IERC SimMan/HPS Simulation Scenario Builder · Web view-obtain and prepare all equipment needed for airway management (mask, suction, oral airway/nasal airway, endotracheal tube with

IERC SimMan/HPS Simulation Scenario Builder

Course/Author: Amanda Murray, MDCourse/Instructor: Amanda Murray, MD, Mojca Remskar Konia, MDPatient Name: Jim SmithScenario Subject: Unanticipated Difficult Airway in the ICU

Educational goals:1. Develop the learner’s ability to make a safe plan for induction and airway

management during an airway code in the ICU.2. Review the indications and contraindications for rapid sequence induction.3. Develop the learner’s communication skills and ability to utilize ICU staff during

an airway code.4. Recognize a difficult airway, appropriately utilize resources to aid airway

management. Recognize when you need help with an airway and ask for help early.

5. Effectively use the ASA difficult airway algorithm to manage a “cannot intubate/cannot ventilate” situation.

6. Develop familiarity and proficiency with a variety of airway management techniques and devices.

7. Teach the basic anatomy and skills to perform a cricothyroidotomy.

Learning Objectives:1. Describe and perform airway and clinical assessment in an ICU patient.2. Identify potential risk factors for a difficult ventilation and intubation.3. Optimize monitoring and positioning of the ICU patient prior to induction. 4. Discuss indications/contraindications for rapid sequence induction.5. Discuss various strategies for induction of anesthesia in the ICU patient.6. Familiarize yourself with the code airway backpack contents, ensure ability to

find and utilize equipment needed from airway backpack for induction.7. Recognize a difficult airway, recognize when you need help with an airway and

ask for help from your senior resident or staff. Direct available resources to manage and secure a difficult airway.

8. Demonstrate proficiency in advanced airway management, including bag-mask ventilation, use of oral and nasal airways, LMA placement, direct laryngoscopy and cricothyroidotomy.

9. List alternative options for airway management when a given technique fails.10. Identify landmarks and describe technique to perform a cricothyroidotomy.

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Learners/Level:-first year anesthesia residents-oral surgery residents

Agenda

16:00 Short orientation to the “Airway Backpack” and general discussion of ICU airway management. Highlight the following:

▪Clinical assessment: clinical history, airway exam, previous intubation notes, important labs/weight ▪Monitoring: turn on pulse oximeter tones, cycle BP Q3min, ensure you can see monitor well from the head of the bed ▪Position patient in sniffing position with shoulder roll if needed and bed at appropriate height to optimize intubation conditions▪Clearly communicate airway plan to ICU team

16:10 Group I: scenarioGroup II: airway backpack, cricothyroidotomy teaching

16:30 Group I: airway backpack, cricothyroidotomy teachingGroup II: scenario

16:50 Debriefing-Groups I and II

17:00 Learners complete session evaluation forms

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Learner preparation

Prior to the session all learners are encouraged to review Miller’s Anesthesia Chapter 42, Airway Management and read the airway articles provided prior to the session. They are also encouraged to explore the airway backpacks on their own and to accompany CA2 residents to floor intubations for firsthand experience.

Instructor preparation

Prior to session, instructors should be familiar with the scenarios and the SimMan human patient simulator. Specifically, instructors will need to know how to change the physiologic parameters in response to learner’s actions. Be prepared to discuss your approach to ICU intubations with learners. Be prepared to discuss the ASA Difficult Airway Algorithm and to teach the anatomy and technique necessary to perform a cricothyroidotomy.

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Written Didactics:

Miller’s Anesthesia, Ch.42, Airway Management

Articles: Please locate and read the two articles indicated below in preparation for the simulation.

1. Practice Guidelines for Management of the Difficult Airway, Anesthesiology 2003: 1269-77. 2. Reynolds, S., Heffner, J. Airway Management of the Critically Ill Patient: Rapid Sequence Intubation. Chest 2005; 127: 1397-1412.

ICU intubation references: References #1 and #2 are found at the end of this curriculum; click on the hyperlinks below to be directed to the corresponding reference. Please read in preparation for the simulation.

1. Airway Management In The Intensive Care Unit, Dr. Richard Prielipp M.D.2. Needle Cricothyroidotomy worksheet

SimLab Large Group Didactics:

Medical Knowledge▪ obtain critical patient information (weight, potassium, airway information/exam)▪ pre-induction set-up in ICU▪ induction drug selection▪ standard induction versus rapid sequence▪ identify “can’t ventilate/can’t intubate” situation, call for help if needed

Procedures▪ ensure all essential monitors are on, working and easily visible according to the situation▪ optimize patient positioning▪ mask ventilation, use of adjuncts such as oral or nasal airway▪ placement of LMA ▪ direct laryngoscopy▪ cricothyroidotomy

Interpersonal and communication skills▪ obtain pertinent clinical information ▪ clearly communicate airway plan to the ICU team▪ communicate need for backup help early▪ utilize ICU team and extra help effectively

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Scenario

Learner orientation

It is assumed that learners have been previously oriented to the SimMan and SimLab setup.Points to reinforce:-familiarity with airway backpack, review of all available drugs and equipment-review rapid sequence (see Chest article)-optimize monitors and patient positioning-obtain and prepare all equipment needed for airway management (mask, suction, oral airway/nasal airway, endotracheal tube with stylet and cuff-tested for leak with a 10cc syringe, end tidal carbon dioxide detector, possibly a bougie and laryngeal mask airway set out of the back table if you are worried about the airway on initial assessment.)-perform appropriate induction of anesthesia-recognize a difficult airway, recognize a need for help, ask for and utilize help appropriately -apply ASA difficult airway algorithm-highlight anatomy and technique for cricothyroidotomy

Instructions prior to clinical scenario▪ Two groups of 3 learners▪ Roles:

1. CA1 resident: ▪ Manages airway:

- assesses the patient- induces anesthesia - noninvasively and invasively manages the airway - organizes activities of others

2. RT▪Performs tasks when asked:

-assists with bag-mask ventilation-applies cricoid pressure-removes ETT stylet-holds ETT in place, helps apply ETCO2 detector

3. RN▪Performs tasks when asked:

-gives clinical information about the patient-assist with positioning, changes monitor setup-draws up induction drugs in syringes, administers drugs-calls for help

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Equipment

▪ SimMan simulator with patent PIV, standard monitors in place per ICU protocol▪ Airway “cold pack” (the plastic container with all necessary drugs for induction)

- 20 cc propofol- 20 cc etomidate- 10 cc succinylcholine- 5 cc rocuronium- 1 cc atropine- 1cc glycopyrrolate-10 cc phenylephrine (100mcg/cc)-10 cc ephedrine (5mg/cc)

▪ “Airway backpack” with all standard equipment available- ETT, stylet, syringe- laryngoscope handle- laryngoscope blades: Miller 2, 3 and MacKintosh 3, 4

- oral and nasal airways- face masks in small adult and large adult sizes- Yankauer suction- ETCO2 detector- laryngeal mask airways in sizes 1,1.5, 2, 2.5, 3, 4 and 5- 10cc syringe (for endotracheal tube)- 20 cc syringe (for laryngeal mask airway)- bougie/endotracheal tube introducer

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Simulation

You are a brand new Clinical Anesthesiology year 2 resident and are called to the medical intensive care unit to intubate a patient who has just been transferred from an outside hospital with pneumonia and increasing respiratory distress. On entering the room, you observe an obese, middle-aged male in respiratory distress with oxygen saturations of 88-92% on 15 liters non-rebreather face mask. He has a patent 18gauge peripheral intravenous line and all standard ASA monitors are in place. There are no records or previous airway notes. The patient is somnolent and cannot answer your questions or participate in an airway examination.

History and Physical

HPI: 54 year old male transferred from outside hospital with pneumonia, now with increasing respiratory distress and probable early sepsis. He was reportedly confused at the outside hospital and was somnolent on arrival to the medical intensive care unit.

PMH: chronic obstructive pulmonary disease, obstructive sleep apnea, hypertension

PSH: Right inguinal hernia repair, 2006

ROS: unable to obtain

Medications: hydrochlorothiazide, aspirin, albuterol, Advair Diskus, tiotropium

Exam:Vital Signs: blood pressure 90/56, heart rate 120, respiratory rate 40 breaths/min, oxygen saturation 88% on 15 liter non-rebreather face maks, weight 134kilogramsGeneral: obese middle aged male, lying in bed, in respiratory distress, face mask in placeAirway: thyromental distance=6cm, thick neck, unable to assess neck range of motion, dentition or mallampati class due to lack of patient cooperationCV: tachycardic, regular rate and rhythm, no murmursPulm: heaving retractions, significant increased work of breathing, scattered rhonchi bilaterallyNeuro: unresponsive to voice, withdraws to painful stimuli

Laboratory:Hemoglobin 14.3Sodium 141Potassium 4.2Chloride 104HCO2 17BUN/creat 18/1.2Glucose 145ABG: 7.28/55/110/18 on 15 liters non-rebreather face ma

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Background and briefing information for coordinator’s eyes only:In this simulation the learner is expected to obtain history and pertinent clinical data, perform a brief clinical evaluation including airway exam, prepare and lay out all necessary airway equipment, ensure all necessary monitors are in place and set appropriately, optimize patient position, relay airway plan to ICU team, perform an IV induction based on their clinical judgment, attempt mask ventilation, place oral or nasal airway, ask for help from ICU team when needed, attempt direct laryngoscopy with grade 4 view and pull back laryngoscope, recognize the need to ask for help from more senior skilled airway expert early, place LMA and check for ability to ventilate patient with the LMA, reassesses and optimizes situation, asks for appropriate help from team, secures airway following the ASA Difficult Airway Algorithm.

Simulation scenario narrative:

Time Course Patient status Desired learner actions

Learner teaching points

1. preinduction ▪ Obtunded, obese male in acute respiratory distress, on BiPAP, PIV and standard ASA monitors in place, unresponsive to questions, withdraws to pain▪ VS:NIBP 105/56 (cycling Q20 minutes), HR 120 (no tones on pulse ox), RR 40, SaO2 88% on BiPAP▪ Clinical information available when team asked: Wt 134kg, Potassium 4.2▪ monitor is turned away so the learner cannot see it.

▪ asks for brief clinical history, pertinent labs, weight▪ performs brief patient evaluation▪ inquires about monitor set up, requests NIBP cycles Q3min, pulse ox tones turned on▪ checks IV access▪ prepares all induction drugs, informs RN clearly about drug doses▪ prepares airway equipment, optimizes set-up at head of bed, ▪ discusses plan for airway management with ICU team

▪ obtain/review patient information in an efficient manner▪ optimize patient monitors, positioning and IV access prior to induction▪ clearly communicate plan for induction to ICU team▪ prepare all needed intubation equipment▪ ensure pre-oxygenation as you set up for intubation▪ utilize ICU team to speed preparations for intubation if needed

2. induction ▪ patient is obtunded, high flow O2 in place, SaO2 stable in 88-90% range▪ after induction, patient RR to 15, then 5, then 0▪ patient SaO2 starts to drop slowly (every 5 seconds) after induction, not being ventilated▪ SaO2 slowly trends down despite addition of

▪ preoxygenates patient▪ announces when induction should begin, repeats drug doses to RN ▪ communicates inability to ventilate patient with one-handed mask▪ utilizes adjuncts such as oral/nasal airway or two-handed mask with help from ICU team

▪ ICU team is there to help you and should be utilized

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adjuncts such as oral/nasal airway/two-handed mask ventilation

3. unsuccessful intubation attempt

▪ VS:BP 140/95, HR 130, SaO2 84%▪ grade 4 view on direct laryngoscopy, SaO2 80%▪ if resident continues to to intubate SaO2 continues to fall to 60%▪ easy LMA placement with adequate ventilation after placement▪ SaO2 improves to 92%

▪ grade 4 view on direct laryngoscopy x 1▪ communicates grade 4 view to team, requests cricoid pressure without improved view▪ requests and places LMA correctly▪ Recognizes chest rise, fog in LMA, confirms breath sounds▪ calls for anesthesiology and surgical backup, prepare for cricothyroidotomy /tracheostomy if necessary

▪ Do not repeat failed technique-change blades, optimize patient position, etc▪ LMA as rescue device in difficult airway algorithm▪ discuss potential for additional airway trauma/fixation errors with multiple DL attempts, consequences of delaying definitive management of hypoxia▪ call for anesthesiology and possibly surgery help early in potential difficult airway situation

4. team planning for definitive airway

▪ SaO2 92% with LMA in place▪ BP 115/56, HR 115

▪ assesses and summarizes situation with ICU team ▪ calls for anesthesiology and surgical backup, prepare for cricothyroidotomy /tracheostomy if necessary

▪ consider alternatives to secure airway-alternative blade, LMA as intubating conduit, FOB, etc▪ ensure optimal patient positioning▪ clear leadership and communication critical during management of airway ▪ call for help early with difficult airway, before problem becomes life-threatening

5. secures airway ▪ SaO2 rises to 95%, BP 125/65, HR 120

▪ communicates grade 3 view to team with change to airway management (new blade/position, etc)▪ communicates successful intubation to team▪ confirms ETCO2, +EBBS after intubation ▪ helps RT secure ETT and get patient on vent▪ calls for anesthesiology and surgical backup, prepare for cricothyroidotomy /tracheostomy if

▪ inform team and write a detailed airway note-highlight what was effective for this patient▪ call for help early with difficult airway, before problem becomes life-threatening

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necessary

Debriefing NoteI. General1. What went well?2. What was difficult?3. Is there anything you think you should have done differently?4. Is there anything you think others should have done differently?

II. Specific1. What were your main concerns from the patient history? From the clinical scenario? 2. What induction drugs did you choose for this patient? Why?3. What adjuncts can you use when ventilation is difficult? 4. Were you effective as the team leader? Is there anything you could have done differently?5. Were there any fixation errors during the scenario?6. Were there any deviations from the difficult airway algorithm?7. What would your next step have been if you were unable to ventilate the patient at all? Able to ventilate but unable to intubate after your second DL?8. What did you change in order to successfully intubate your patient? Was this a realistic change that has worked for you in real life? 9. How would your plan for airway management have changed in an obese patient with a thick, short neck? What resources and/or strategies are available to you to help secure this type of airway?

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Unanticipated Difficult Airway EvaluationName:____________________________

General□ acts professionally□ reviews history, obtains critical labs, performs brief clinical exam□ wears gloves

Equipment and Set Up□ optimizes monitors: sets NIBP to cycle, turns on pulse ox tones, can see monitor from head of bed□ ETT, stylet and syringe□ laryngoscope handle with functioning light□ laryngoscope blades□ oral/nasal airway□ working suction□ ETCO2 detector□ Ensures patent IV access□ Ensures pre-oxygenation during set-up

Induction/Difficult airway sequence□ clearly communicates plan for intubation with team□ clearly communicates induction drugs and doses to RN□ optimizes patient position□ attempts bag-mask ventilation-one person□ attempts bag-mask ventilation-two people□ uses oral/nasal airway□ attempts LMA□ attempts intubation ≤ 2 times on own□ does not repeat failed technique□ calls for help□ confirms ETCO2 and EBBS after successful intubation□ helps secure ETT□ continually reassesses vital signs during scenario

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Unanticipated Difficult Airway EvaluationName:_____________________________

General□ acts professionally□ reviews history, obtains critical labs, performs brief clinical exam□ wears gloves

Equipment and Set Up□ optimizes monitors: sets NIBP to cycle, turns on pulse ox tones, can see monitor from head of bed□ ETT, stylet and syringe□ laryngoscope handle with functioning light□ laryngoscope blades□ oral/nasal airway□ working suction□ ETCO2 detector□ Ensures patent IV access□ Ensures pre-oxygenation during set-up

Induction/Difficult airway sequence□ clearly communicates plan for intubation with team, communicates changes in plan as needed□ clearly communicates induction drugs and doses to RN□ optimizes patient position□ attempts bag-mask ventilation-one person□ attempts bag-mask ventilation-two people□ uses oral/nasal airway□ attempts LMA□ attempts intubation ≤ 2 times on own□ does not repeat failed technique□ asks for help from team-cricoid pressure/two handed mask, etc.□ confirms ETCO2 and EBBS after successful intubation□ helps secure ETT□ continually reassesses vital signs during scenario

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Simulation Evaluation FormUnanticipated Difficult Airway in ICULevel of Training: CA1 ResidentsDate 11/3/2009

Goals and objectives:1. Orient residents to airway backpack2. Orient residents to floor intubation routines, discuss potential problems and differences between OR inductions and intubations versus floor inductions and intubations3. Review the ASA Difficult Airway Algorithm

Was it helpful to do the scenario?

strongly agree agree neutral disagree strongly disagree1 2 3 4 5

Comments:_____________________________________________________________________________________________________________________________________

strongly agree agree neutral disagree strongly disagree1 2 3 4 5

Comments:_____________________________________________________________________________________________________________________________________

What did you learn from the scenario? What was most helpful?________________________________________________________________________________________________________________________________________________

What was the least helpful aspect of the scenario?________________________________________________________________________________________________________________________________________________

What would you change to make this more helpful/instructive?________________________________________________________________________________________________________________________________________________

What other scenarios do you think would be helpful to your education?________________________________________________________________________________________________________________________________________________

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Needle cricothyroidotomy (Back to Written Didactics)

Anatomy

Image retrieved on December 15th from:

www.wikipedia.org/wiki/File:Larynx_external_en.svg

Creative Commons license associated: creativecommons.org/licenses/by-nc-nd/3.0/

Technique

1. ID landmarks as above, clean area over cricothyroid membrane with alcohol swab2. Advance sterile, 14 gauge angiocatheter with a syringe attatched ½”-3/4”,

aspirating continually until you get air return. If you go too far, you may puncture the esophagus, so use care and aspirate slowly.

3. Once you aspirate air, direct needle toward sternal notch and cast off 14 gauge angiocatheter from needle, so catheter remains in trachea. Remove and safely dispose of your needle.

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4. Attach the plastic connector from a 4.0 ETT to the hub of your 14 gauge angiocatheter.

5. Provide ventilation via a bag-valve device with the highest available concentration of oxygen.

6. Call for jet ventilator to oxygenate patient at 20psi per breath. If a jet ventilator is not available, move to step #7.

7. Thread guidewire through angiocatheter down into trachea, remove angiocatheter, enlarge vertical cricothyroidotomy incision with scalpel and insert a 5.5 or 6.0 endotracheal tube through the incision site, over the guidewire. Secure endotracheal tube and bag-mask ventilate.

8. Confirm chest rise and bilateral breath sounds.9. Assess ability to oxygenate. 10. Assess ability to ventilate if an endotracheal tube has been placed by guidewire

via the cricothyroidotomy incision.11. Secure airway by wrapping tape around catheter well, then from catheter around

back of neck and back to catheter on opposite side.

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AIRWAY MANAGEMENT CONSIDERATIONS IN THE ADULT INTENSIVE CARE UNIT

(Written Didactics)

Learning Objectives:1. To appreciate the increased morbidity/mortality profile of airway interventions in

the adult intensive care unit.2. To understand the multiple variables affecting airway management decisions in

the critically ill adult and how they may significantly differ from adults presenting to the operating room.

3. To integrate pertinent critical care literature into airway management decision making in adult critical care patients.

Introduction:Anesthesia providers are frequently summoned to provide airway management expertise for nonoperative patients in clinical areas outside of the operating room. One particularly challenging environment commonly requesting such services is the intensive care unit (ICU). The critically ill represent a unique subset of patients whose underlying pathophysiologic derangements geometrically increase their risks of morbidity and mortality from a variety of airway interventions, which often must occur urgently or emergently under uncontrolled conditions. As such, it is incumbent upon anesthesia care givers to understand the multiple variables affecting airway manipulations in the adult critical care patient and associated factors that often differ from more routine surgical patients presenting to the operating room.

Airway Management Adverse Outcomes: The American Society of Anesthesiologists (ASA) Closed Claims StudyThe ASA Closed Claims Study represents our specialty’s systematic evaluation of adverse events associated with suboptimal airway management outcomes. While this database is primarily derived from intraoperative and immediate perioperative recovery periods, it provides a useful foundation from which to project the likelihood of such outcomes from airway management misadventures in the critically ill. Current information derived from this multi-decade effort is temporally summarized in the table 1 below (1-4):

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TABLE 1: SUMMARY OF ASA CLOSED CLAIMS STUDY RESULTS

EVENT(S) % CLAIMS% DEATH/BRAIN

DAMAGE (BD) ASSOCIATED COMMENTSAdverse Respiratory 37.2% 74.8% single largest class of injury

Inadequate oxygenation/ventilation

7% >90% Cheney, 1991; Miller, 2000

Esophageal intubation 4.5% >90% Cheney, 1991; Miller, 2000Airway obstruction 3% 87% 70% upper airway

Difficult intubation (DI) 6.4% 57% ▪ risk factors: increased age, ASA 3 or 4, obesity▪ DI anticipated in only 50%▪ airway history or physical exam in only 25%, respectively

Airway (AW) injuries 6% 8% (death) ▪ trachea, pharynx, or esophagus in 2/3rds▪ pharyngoesophageal (PE) and tracheal injuries associated with DI▪ PE injury risk factors – female, age >60

Difficult AW <4% 63% ▪ 67% induction, 12% extubation, 5% recovery▪ death/BD during induction ↓ 44% after Diff. AW algorithm; no change in death/BD during other time periods▪ 25% AW emergencies (can’t intubate, can’t ventilate): 86% death/BD▪ persistent intubation attempts, airway “rescue maneuvers" during AW emergencies: poor outcomes

What Do We Know About The Risks of Airway Management Interventions in the ICU?Airway management literature from the critical care environment is significantly confounded by the heterogenous nature of this patient population, their underlying critical illness/comorbidities, and their various indications for definitive airway control. As such, these data must be carefully scrutinized and interpreted with caution.

Unplanned extubation (UE) of mechanically ventilated ICU patients is one particularly common scenario generating emergent calls for anesthesia airway expertise. Reintubation rates after UE range between 23-77%, with surgical ICU (SICU) patients appearing less likely to require reintubation compared to those in the medical ICU (MICU) (5-6). Reintubation rates also appear lower in younger patients and those undergoing active weaning from mechanical ventilation (5-7). Not surprisingly, factors such as inadequate sedation and agitation have been consistently associated with UE in many series. While the timing of reintubation after UE is arbitrarily limited to a specific time period in some studies (typically within 24-72 hours after UE) (5-8) or not specified in others (9), studies reporting such data suggest that the majority of UE patients requiring reintubation do so within the first 2 hours (7,10). Although ICU patients experiencing UE do not have worse

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outcomes compared to either the ICU study population or matched case controls (6-9), some data suggest that UE patients requiring reintubation have an increased risk of ICU and/or in-hospital mortality compared to those not requiring reintubation (6-7).

Are the risks associated with reintubation after UE higher, the same, or lower than these same risks during intubation in the operating room? Table 2 below summarizes recent literature on adverse outcomes from out-of-OR airway management and emphasizes the increased risk profile associated with intubating an ICU patient (10-14):

TABLE 2: COMPLICATIONS OF ICU AIRWAY MANAGEMENTEVENT % INCIDENCE ASSOCIATED COMMENTS

Difficult Intubation (DI) 8-14% ▪ historical incidence in anesthesia literature 1-3%

Esophageal Intubation (EI) 5-14% ▪ increased incidence with > 2 DLsRight Mainstem Intubation 4-5%Hypoxemia (SpO2 < 90%) 12-26% ▪ increased incidence with > 2 DLs

▪ increased incidence with EI▪ increased incidence with regurgitation and/or aspiration

Severe Hypoxemia (SpO2 < 70-80%)

6-26% ▪ same as hypoxemia above

Hypotension 25-35% - no relationship to # of DLsSurgical Airway 2-20% ▪ highest incidence in cardiac arrest

associated with DICardiac Arrest 2-3% ▪ more likely with preintubation ↓ BP

▪ increased incidence with > 2 DLs▪ common pattern: severe hypoxemia → bradycardia → asystole ▪ approx. 25% had preDL SpO2 < 90%▪ 15-20% required surgical airway▪ up to 38% survival to hospital discharge

Two studies derived from a large quality improvement database of non-OR intubations by anesthesia providers utilizing direct laryngoscopy (DL) over more than a decade warrant specific mention. Approximately 70% of these intubations occurred in the ICU and another 10% in the Emergency Department (which I would consider a critical care environment). The first reported a series of 2833 emergency intubations over a 10 year period and demonstrated a 10% incidence of difficult intubation. One particularly ominous finding was that rates of hypoxemia (SpO2 < 90%), severe hypoxemia (SpO2 < 70%), esophageal intubation, and cardiac arrest within 5 minutes of intubation were 70%, 28%, 51%, and 11%, respectively, in the DI group compared to 10.5%, 1.9%, 4.8%, and 0.7% in those patients requiring 1 or 2 DLs (12). A more recent study utilizing the same database subsequently reported 60 cardiac arrests within 5 minutes of emergency intubation in 3035 patients over an 11 year period. These arrests exhibited a consistent pattern initially heralded by severe hypoxemia precipitously followed by bradycardia and asystole. The rates of DI and EI in this series were 62% and 63% respectively, and a surgical airway was ultimately performed in 20% of cases. One- and 7-day mortality rates

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were 27% and 50%, respectively, and only 38% of arrest victims survived neurologically intact to hospital discharge (13).

For those who remain unconvinced about the high-risk nature of ICU airway management, the ASA Closed Claims Study recently contributed further sobering support of this concept. Peterson and colleagues reported a subset of 23 difficult airway claims occurring in “outside locations” other than the operating room. The vast majority of this group was sick (ASA 3 or 4) inpatients and approximately half were emergency situations in nonsurgical patients. Reintubation for postoperative swelling of the head/neck and ETT exchange each accounted for 25% of these claims. The incidence of death or brain damage in this subgroup was 100%. The authors felt these results “may reflect the lack of operating room resources of standard airway management equipment or the lack of immediate availability of healthcare providers skilled in airway management” (4).

ICU Airway Management: Initial ConsiderationsMy general approach to managing the ICU airway involves emergently responding to the patient’s bedside with as many airway options as can be expediently accessed at the time expertise is requested (i.e., an airway “bag”). Once at the bedside, I simultaneously acquire a brief, focused history of the patient’s current hemodynamic and pulmonary status from the bedside providers while rapidly performing a screening airway /cardiorespiratory “primary survey” (table 3).

TABLE 3: RAPID ICU AIRWAY MANAGEMENT “PRIMARY SURVEY”Color/cyanosis/conjunctiva Carotid pulse/capillary refill/JVD

Retractions/paradoxical respiratory efforts Tracheal position/surgical AW landmarksSnoring/stridor/hoarseness Breath sounds/chest excursion

Difficult airway traits Mental status/agitationPresence/absence of protective reflexes Vital signs/ SpO2

My goal from this process is to triage the airway situation into 1 of 3 categories within 5 minutes of arrival: (1) a true, high-risk, life-threatening airway emergency requiring immediate intervention under current conditions (these are usually self evident), (2) an urgent, moderate risk airway situation which can potentially be managed semi-electively under more controlled conditions, or (3) an elective clinical scenario where conditions should be optimized to maximize success of the chosen airway intervention while minimizing the risk of patient decompensation. Ongoing vigilance, close clinical monitoring, and frequent reevaluation are mandatory in the latter two categories, and providers should be fully prepared to “kick it up a notch” should the patient begin to deteriorate.

An underrepresented, but equally important component to successful ICU airway management is the mental and psycho-emotional preparation of the airway provider(s). These are commonly dynamic, highly stressful, and poorly controlled clinical situations with the constant potential for precipitous, life-threatening deterioration. Such high-risk scenarios are the antithesis of a well-planned, methodical, controlled anesthetic induction with which anesthesia providers are most comfortable. Emergent clinical decisions must

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frequently be based on skimpy, incomplete information, and the patient is often less than fully cooperative due to hypoxemia, respiratory distress, sepsis, shock, sedatives/ analgesics, and/or their underlying critical illness. Death from inability to successfully manage an ICU airway can devastate the confidence of the airway provider irrespective of level or experience (15), and anesthesia team members must accept that their well-intentioned airway efforts will occasionally result in a devastating outcome.

ICU Airway Management: The Unsecured AirwayThe ASA Practice Guidelines for Management of the Difficult Airway (16) represents the criterion standard by which airway management issues should be approached irrespective of location, and I would argue it is as equally applicable in the ICU as it is in the Operating Room. That said, consistent implementation of the guideline’s recommendations in the ICU may prove problematic due to lack of advanced airway equipment, knowledge/skill deficiencies of ancillary bedside staff, and/or patient-specific contraindications (for example, nasal intubation in an anticoagulated patient).

Rather than expend time and energy reviewing the ASA Difficult Airway algorithm (which we have all seen countless times), I have elected to focus on airway management aspects unique to the ICU based upon my 20+ years of ICU experience and pertinent critical care literature. Please consider the following “Kelly’s Tips for ICU Tubes” (presented in no particular order) as adjuncts to the ASA Difficult Airway algorithm in appropriately managing the ICU airway.

Tip #1: “Tag – You’re It”. Respond anticipating this will be a high-risk, emergency airway situation requiring immediate stabilization in a setting of limited airway equipment availability and suboptimal assistance from bedside paramedical personnel. Frustration is the enemy of performance under duress, and it is much better to be pleasantly surprised when adequate equipment and help are indeed available.Tip #2: “You’re Not In Kansas Anymore, Dorothy”. The ICU is an ergonomically challenging environment for managing an unstable airway. Ventilators, infusion pumps, continuous dialysis machines, central lines, and intracranial pressure monitors crowd the head of the bed. Nasogastric/feeding tubes and cervical collars interfere with mask ventilation and laryngoscopy. Inflatable skin care beds make it difficult to optimally position patients, particularly if head of bed elevation is required. This is the OR – NOT!Tip #3: Is Intubation/Reintubation Clinically Indicated At This Time? Avoid the urge to be a technician and independently evaluate whether intubation is clinically indicated under current conditions. In my experience, most situations requiring immediate intubation are readily apparent upon arrival at the bedside and should be handled accordingly. In the remainder of cases, a more systematic evaluation of the patient’s current condition and anticipated near-term course (which may require direct communication with the patient’s physician team) may be warranted before making a decision to intubate (or not). The 40% TBSA burn patient with inhalation injury may need intubated early while clinically stable knowing that he/she will likely develop significant upper/lower airway edema during their Parkland formula fluid resuscitation. Alternatively, a young patient S/P exploratory laparotomy for traumatic liver and splenic lacerations who self-extubates during active weaning from mechanical ventilation and

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who is breathing comfortably with adequate oxygen saturation may warrant a “trial of extubation” with close clinical monitoring.Tip #4: Time Permitting, Find Any Previous Intubation Notes and Read Them. The details found in intubation notes provide valuable information (intubating provider, blade, taping depth, etc.) regarding what was previously successful (or unsuccessful) in the same patient. Such information must then be extrapolated to the patient’s current condition to evaluate its applicability (or lack thereof). Documentation of previous airway management difficulties earlier in the patient’s hospitalization portends similar problems with current airway management unless the patient has improved significantly in the interim. Conversely, an uneventful intubation 2 weeks previously for elective surgery may no longer be applicable in a patient who subsequently develops postoperative sepsis and multisystem organ failure.Tip #5: Place A Large (Preferably ≥ 7.5 mm), High Volume, Low Pressure Endotracheal Tube (ETT) If Possible. While any ETT is better than no ETT in a patient death spiraling toward cardiac arrest, a high volume, low pressure ETT better distributes a lower ETT cuff pressure along the tracheal mucosa and may decrease the incidence of post-intubation airway complications. I also recommend strong consideration for placing a 7.5 mm (or larger) ETT in almost all adults in the ICU to allow for diagnostic and/or therapeutic fiberoptic bronchoscopy (FOB) during the patient’s ICU course and minimize requests for ETT exchange to permit same.Tip #6: Strongly Consider The Pros and Cons Of Maintaining Spontaneous Ventilation. To quote my mentor, Dr. Donald Prough, “The only thing worse than a critically ill patient with a bad airway is a critically ill patient with no airway.” The pharmacodynamic effects of sedatives, anesthetic agents, and/or neuromuscular blocking drugs superimposed upon the patient’s underlying critical illness have an unpredictable interaction that may turn a bad airway situation into a crisis. Alternatively, maintenance of airway patency and spontaneous ventilation potentially allows insufflation of supplemental oxygen during airway manipulations while not pharmacologically “burning any bridges.” Many ICU airway scenarios unfortunately mandate taking a “safety first, comfort second” approach, and I have personally found air hunger to be a valuable factor in securing patient cooperation for unsedated DL attempts.Tip #7: “Ah, Yes, The Nose, The Nose” (See Allen, Woody, “Sleeper”). Blind nasotracheal intubation is a vastly underutilized technique (in my opinion) and can potentially stabilize the airway in rapid fashion with minimal equipment and limited patient cooperation when spontaneous respiratory effort is present. Air hunger is again a valuable adjunct with this technique, and some patients literally “suck the tube in” due to their exaggerated inspiratory efforts. If successful, the nasotracheal tube should be replaced with an orotracheal tube or tracheostomy as soon as the patient stabilizes due to the association between nasotracheal intubation and nosocomial sinusitis (17). Tip #8: “Hear The Sirens Of Oxygen Desaturation”. Critically ill patients commonly have a significant imbalance between low oxygen supply (low functional residual capacity, low PAO2, hypercapnia, hypovolemia, low cardiac output, anemia) and high oxygen consumption (catabolic stress, fever, tachycardia, tachypnea, seizures, agitation, etc.) (18). The current transfusion trigger in many ICUs is a hemoglobin < 7 grams/dl based upon data supporting lower mortality with restrictive transfusion strategies (19). These lower hemoglobin concentrations (which disproportionately lower arterial oxygen

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content relative to a low PaO2) significantly magnify the limited efficacy of preoxygenation prior to DL in the critically ill (20). The oxygen desaturation data summarized above in table 2 are thus not particularly surprising given such conditions and in large part explain my preference to maintain spontaneous ventilation if at all possible. Tip #9: Should Your Plan “B” Be A Surgical Airway? While the majority of anesthesia providers are confident in their supraglottic airway management skills and have a historically high rate of translaryngeal intubation success, it is also true that some critically ill patients would be best served by skilled surgical airway expertise (either primarily or as a backup at the bedside or in the operating room). The thrombocytopenic leukemia patient with trismus, drooling, 1 finger breadth mouth opening, and an exquisitely tender fist-sized mass filling the sublingual space down to 2 finger breadths above the suprasternal notch (an actual case I was presented with recently) obviously mandates extremely cautious airway manipulation, and it is no “sign of weakness” to defer to a skilled otolaryngologist under such circumstances. It is similarly intuitive that surgical airways performed semi-electively or electively will likely result in better outcomes. Sixty-four percent of tracheal injuries reported from the ASA Closed Claims Study were related to surgical tracheostomy, 84% of which were emergently performed during DI situations (2). Peterson’s more recent report from this same database documented 75 closed claims from emergency airway situations. Seventy-six percent of these cases had surgical airways attempted; the incidence of death/BD in these cases was 84% (4). Anesthesia providers practicing in hospitals where surgical airway expertise is not immediately available may want to consider acquiring skill in performing a surgical cricothyroidotomy. Percutaneous cricothyroidotomy kits utilizing the Seldinger technique are commercially available and may warrant routine ICU stocking under such conditions. Tip #10: “Never Do The ICU Airway Boogie Without A Bougie”. In my experience, the gum elastic bougie (GEB) is the most valuable, easily available adjunct for ICU intubations and may be particularly useful in patients with limitations in mouth opening or cervical spine mobility (21). A recently published Australian study of 147 DIs demonstrated that 46% were successfully managed utilizing a GEB (22).Tip #11: Helpful Colleagues May Be Unhelpful. A recent emergency medicine cadaver study suggests that cricoid pressure and backward-upward-right(ward) pressure (BURP) applied by assisting practitioners significantly worsens laryngoscopic views using a curved blade compared to laryngoscopist-directed thyroid cartilage manipulation (23). These findings are consistent with the above mentioned Australian study, which found only 11% of the DIs were ultimately intubated utilizing patient repositioning, cricoid pressure, or BURP (22).Tip #12: Consider Using A Straight Blade. Limited mouth opening and inability to consistently place ICU patients in a reasonable “sniffing position” makes a straight blade more efficacious in my hands under such circumstances. Indeed, one recent study from the anesthesia literature suggests that laryngoscopic views obtained with a straight blade were statistically superior to those obtained with a curved blade (24). Furthermore, the posterior oropharynx commonly contains orogastric and/or feeding tubes, making the lower straight blade profile advantageous. The GEB is particularly valuable under such circumstances.

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Tip #13: Choose Your Anesthetic And Sedative Agents Wisely (If At All). While etomidate’s hemodynamic stability makes it an appealing agent for ICU airway management, emerging evidence suggests its adrenal suppressive properties may have deleterious consequences in this population (25, 26). Benzodiazepine administration in the critically ill has been associated with agitation, UE, and delirium (9, 27). Individual ICU patients manifesting partial upper airway obstruction potentially may worsen with sedative doses of propofol and midazolam (28). Topical benzocaine can cause methemoglobinemia and adversely affect systemic oxygenation (29). Tip #14: “Do You Feel Lucky, Punk?” (see Eastwood, Clint, “Dirty Harry). While succinylcholine appears to be commonly administered during ICU airway management (11-14), factors such as thermal burns, disuse atrophy, upper/lower motor neuron denervation, and therapeutic glucocorticoid administration may predispose the critically ill to succinylcholine-induced hyperkalemia and subsequent cardiac arrest (30). Furthermore, a computer model simulating the rate of oxygen desaturation during complete upper airway obstruction after administration of succinylcholine 1 mg/kg suggests that critical oxygen desaturation (defined as an SpO2 < 80%) occurs 3-5 minutes before single twitch height recovers to 50% of control in a typical critical care patient (18).Tip #15: Write An Appropriately Detailed Intubation Note, Including Post-Intubation Chest X-Ray (CXR) Findings (Or Which Physician Has Actively Assumed Responsibility For Checking Same). See tip #4 above. I am personally aware of 2 malpractice litigations where anesthesiologists were named defendants primarily because of questions involving ETT position on the post-intubation CXR. Lack of timely CXR interpretation and implementation of appropriate corrective actions were alleged to be the proximate cause of cardiac arrest in both cases.

ICU Airway Management: Anesthesia “Standby” For High-Risk ExtubationAnother ICU scenario which anesthesia providers are commonly presented with involves “standby” for high-risk patients undergoing elective/semi-elective extubation. Typical examples might be DI patients who were successfully intubated, patients with obstructive sleep apnea (OSA), mentally challenged adults, high spinal cord injuries, and patients with impaired sensorium from a variety of causes. While many of the “tips” detailed above continue to apply to “standby” extubations, some additional ones are worthy of consideration:

Tip #16: Is This Patient An Appropriate Candidate For A “Trial” Of Extubation? Anesthesia care givers need to again resist the urge to be technicians and ensure that the patient has met appropriate criteria for possible extubation. Acceptable mentation, minimal secretions, presence of protective airway reflexes, adequate oxygenation on nontoxic oxygen concentrations with minimal PEEP, absence of significant tachypnea or respiratory extremis, and a limited trial of spontaneous breathing are commonly utilized (31, 32). Tip #17: Is Residual Nondepolarizing Neuromuscular Blockade Present? Low plasma levels of nondepolarizing neuromuscular blocking agents adversely affect upper airway patency and coordinated pharyngeal swallowing. Both of these vital airway functions do not reliably return until recovery to a train-of-four ratio ≥ 0.9 occurs, a ratio

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not exceeded for 2 hours or more in a significant number of patients after a single intubating dose of an intermediate acting nondepolarizer (33, 34). Because patients incompletely recovered from nondepolarizing neuromuscular blockade may meet other criteria commonly used in ICU extubation paradigms (forced vital capacity, negative inspiratory force), it is important to clinically demonstrate absence of significant residual blockade (with maneuvers such as sustained head lift and tongue protrusion to command) since airway obstruction and inability to handle oropharyngeal secretions will not manifest themselves until the ETT “stent” is removed (35). Incomplete recovery from long-acting (but not intermediate-acting) nondepolarizing neuromuscular blockade has been previously associated with the development of postoperative pulmonary complications (36).Tip #18: Should I Check For An ETT Cuff Leak? Certain ICU patients (such as those with significant head/neck edema) present concern about upper airway compromise after ETT “stent” removal and may warrant testing for an ETT cuff leak. This can be done using positive pressure and a stethoscope on the anterior neck (as with uncuffed ETTs in children) or by temporary cuff deflation followed by a request for the patient to cough or phonate in those awake and cooperative. Absence of a clinical leak (my arbitrary threshold being ≤ 25 cm of water) in an appropriate situation should lead to thorough reevaluation regarding whether to proceed. I have on rare occasions taken ICU patients to the operating room with ENT standby for controlled extubation and immediate post-extubation monitoring (similar to the “double set-up” approach for children with epiglottitis). Tip #19: Should I Consider Extubating Over An Airway Exchange Catheter (AEC)? In patients with a known or suspected difficult airway, extubation over an indwelling AEC permits continuous distal insufflation of supplemental oxygen as well as support of ventilation utilizing either a bag-valve-15 mm adaptor system or a jet venturi apparatus. It can safely remain in the trachea with acceptable patient tolerance for a number of hours until the clinical risk of reintubation appears unlikely (37). Should extubation failure occur, the AEC can be utilized as an intubating stylet while limiting oxygen desaturation with simultaneous oxygen insufflation during reintubation (37). I am aware of one institution which has a 90% reintubation success rate with 1-2 attempts utilizing the AEC for this indication while reporting low rates of hypoxemia, esophageal intubation, and/or use of airway rescue devices (personal communication). Use of an AEC to support ventilation with an in situ ETT and its associated risk of barotrauma will be discussed in the next section.Tip #20: Is It Known Or Likely That This ICU Patient Has OSA? OSA patients can be particularly challenging to optimize prior to extubation and require a multifaceted plan to maximize extubation success while minimizing pharmacologic respiratory depression, anatomic impairment with ventilation, and subsequent need for reintubation. Analgesic requirements (regional analgesia, nonsteroidal antiinflammatory agents if applicable), ETT tolerance during ventilator weaning (dexmetotomidine’s absence of effect on CO2 response is appealing), patient positioning (sitting upright or reverse Trendelenburg), appropriate application of airway adjuncts (nasopharyngeal airway), and post-extubation interventions (i.e., immediate application of noninvasive positive pressure ventilation) should all be considered in plan development. The recent ASA guidelines in this area

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provide the latest consensus regarding management of this increasingly common problem (38).

ICU Airway Management: ETT ExchangeETT exchange represents the final ICU scenario worthy of comment to anesthesia providers. Some of my most unsatisfying airway experiences have involved exchanging ETTs in ICU patients, and I approach this procedure with great respect and guarded caution. Each ETT exchange must be individually evaluated to ensure appropriate indication(s) exist, and a technician-like approach is strongly discouraged. Providers can limit the number of ETT exchange requests by placing ETTs of sufficient diameter to allow diagnostic/therapeutic FOB (see tip #5). In addition to many of the previously mentioned “tips”, further consideration should be given to the following:

Tip #21: Should The ETT Be Advanced, Pulled Back, Or Removed (See Tips #15 and 16). Evaluation of ETT insertion depth (say, 18 cm or 26 cm at the lip, respectively), clinical examination (limited chest excursion/audible air escape or asymmetric chest rise/breath sounds, respectively) and review of the patient’s daily CXR (ETT tip barely at the thoracic inlet or in the right main stem bronchus, respectively) may readily explain a patient’s significant ETT cuff leak or “mucous plug” and dictate appropriate ETT repositioning (rather than exchange). Similarly, certain patients may meet appropriate criteria for rapid weaning and “liberation” from mechanical ventilation rather than subjected to unnecessary (and potentially dangerous) ETT exchange.Tip #22: Should I Perform The ETT Exchange Under Direct Visualization Or Utilize A “Blind” Technique? While either approach may be appropriate in a given patient, I personally favor carefully moving the ETT to the left corner of the mouth and doing an initial DL to evaluate the “lay of the land” in most circumstances. My rationale is that DL will almost always be one’s “plan B” should a blind technique go awry, so it is better to discover a grade 4 laryngoscopic view with an in situ ETT rather than when you can’t advance the new ETT blindly into the now unsecured airway. Should DL provide adequate glottic visualization, I proceed with the ETT exchange using a styletted ETT. Inadequate glottic visualization usually causes me to reevaluate and consider other options (AEC, FOB, tracheostomy, etc.). While blind ETT exchange has been described utilizing either a rigid plastic “tube changer” or an AEC (37), significant barotrauma has been reported with such techniques (39, 40). Tip #23: ETT Exchange Utilizing An AEC Requires Close Attention To Detail. While the AEC can be an invaluable adjunct in safely performing ETT exchange, barotrauma may result when it is used for “rescue” jet ventilation while positioned into a main stem bronchus through an existing ETT (40). Care must be taken to (a) maintain AEC position well within the trachea (typically utilizing a combination of ETT insertion depth and distance from the ETT tip to the carina on CXR) and (b) provide sufficient room between the AEC outer diameter and the ETT inner diameter to allow for passive exhalation and avoid air trapping (41). Tip #24: Consider Providing Chlorhexidine Oral Care Prior To Performing ETT Exchange. Similar to sterilely prepping the central line site and catheter prior to changing a preexisting line over a guide wire, it seems intuitive to provide chlorhexidine oral care prior to ETT exchange given data supporting lower rates of ventilator-associated

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pneumonia in mechanically ventilated patients receiving such daily care (42). This recommendation is supported by evidence of an increased rate of nosocomial pneumonia in patients requiring reintubation due either to UE or extubation failure after appropriate weaning (8).

ConclusionICU airway management presents unique challenges to airway providers in a high-risk patient care environment. Anesthesia care givers must have sufficient knowledge of common ICU airway issues to properly apply their judgment, skill, and expertise toward optimizing patient outcomes while minimizing morbidity and mortality.

References1. Cheney FW, Posner KL, Caplan RA. Adverse respiratory events infrequently

leading to malpractice suits. A closed claims analysis. Anesthesiology 1991;75:932-9.

2. Domino KB, Posner KL, Caplan RA, et al. Airway injury during anesthesia: a closed claims analysis. Anesthesiology 1999;91:1703-11.

3. Miller CG. Management of the difficult intubation in closed malpractice claims. American Society of Anesthesiologists NEWSLETTER 2000;64:13-19.

4. Peterson GN, Domino KB, Caplan RA, et al. Management of the difficult airway: a closed claims analysis. Anesthesiology 2005;103:33-9.

5. Razek T, Gracias V, Sullivan D, et al. Assessing the need for reintubation: a prospective evaluation of unplanned endotracheal extubation. J Trauma 2000;48:466-9.

6. Krinsley JS, Barone JE. The drive to survive: unplanned extubation in the ICU. Chest 2005;128:560-6.

7. Epstein SK, Nevins ML, Chung J. Effect of unplanned extubation on outcome of mechanical ventilation. Am J Respir Crit Care Med 2000;161:1912-6.

8. de Lassence A, Alberti C, Azoulay E, et al. Impact of unplanned extubation and reintubation after weaning on nosocomial pneumonia risk in the intensive care unit: a prospective multicenter study. Anesthesiology 2002;97:148-56.

9. Tung A, Tadimeti L, Caruana-Montaldo B, et al. The relationship of sedation to deliberate self-extubation. J Clin Anesth 2001;13:24-9.

10. Mort TC. Unplanned tracheal extubation outside the operating room: a quality improvement audit of hemodynamic and tracheal airway complications associated with emergency tracheal reintubation. Anesth Analg 1998;86:1171-6.

11. Schwartz DE, Matthay MA, Cohen NH. Death and other complications of emergency airway management in critically ill adults. A prospective investigation of 297 tracheal intubations. Anesthesiology 1995;82:367-76.

12. Mort TC. Emergency tracheal intubation: complications associated with repeated laryngoscopic attempts. Anesth Analg 2004;99:607-13.

13. Mort TC. The incidence and risk factors for cardiac arrest during emergency tracheal intubation: a justification for incorporating the ASA Guidelines in the remote location. J Clin Anesth 2004;16:508-16.

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14. Jaber S, Amraoui J, Lefrant JY, et al. Clinical practice and risk factors for immediate complications of endotracheal intubation in the intensive care unit: a prospective, multiple-center study. Crit Care Med 2006;34:2355-61.

15. Sklar DP. A piece of my mind. The intubation. JAMA 1992;268:1072.16. American Society of Anesthesiologists Task Force on Management of the

Difficult Airway. Practice guidelines for management of the difficult airway: an updated report by the American Society of Anesthesiologists Task Force on Management of the Difficult Airway. Anesthesiology 2003;98:1269-77.

17. Holzapfel L, Chastang C, Demingeon G, et al. A randomized study assessing the systematic search for maxillary sinusitis in nasotracheally mechanically ventilated patients. Influence of nosocomial maxillary sinusitis on the occurrence of ventilator-associated pneumonia. Am J Respir Crit Care Med 1999;159:695-701.

18. Benumof JL, Dagg R, Benumof R. Critical hemoglobin desaturation will occur before return to an unparalyzed state following 1 mg/kg intravenous succinylcholine. Anesthesiology 1997;87:979-82.

19. Vincent JL, Piagnerelli M. Transfusion in the intensive care unit. Crit Care Med 2006;34(5 Suppl):S96-101.

20. Mort TC. Preoxygenation in critically ill patients requiring emergency tracheal intubation. Crit Care Med 2005;33:2672-5.

21. Nolan JP, Wilson ME. Orotracheal intubation in patients with potential cervical spine injuries. An indication for the gum elastic bougie. Anaesthesia 1993;48:630-3.

22. Paix AD, Williamson JA, Runciman WB. Crisis management during anaesthesia: difficult intubation. Qual Saf Health Care 2005;14:e5.

23. Levitan RM, Kinkle WC, Levin WJ, et al. Laryngeal view during laryngoscopy: a randomized trial comparing cricoid pressure, backward-upward-rightward pressure, and bimanual laryngoscopy. Ann Emerg Med 2006;47:548-55.

24. Arino JJ, Velasco JM, Gasco C, et al. Straight blades improve visualization of the larynx while curved blades increase ease of intubation: a comparison of the Macintosh, Miller, McCoy, Belscope and Lee-Fiberview blades. Can J Anaesth 2003;50:501-6.

25. Malerba G, Romano-Girard F, Cravoisy A, et al. Risk factors of relative adrenocortical deficiency in intensive care patients needing mechanical ventilation. Intensive Care Med 2005;31:388-92.

26. Jackson WL Jr. Should we use etomidate as an induction agent for endotracheal intubation in patients with septic shock?: a critical appraisal. Chest 2005;127:1031-8.

27. Pandharipande P, Shintani A, Peterson J, et al. Lorazepam is an independent risk factor for transitioning to delirium in intensive care unit patients. Anesthesiology 2006;104:21-6.

28. Norton JR, Ward DS, Karan S, et al. Differences between midazolam and propofol sedation on upper airway collapsibility using dynamic negative airway pressure. Anesthesiology 2006;104:1155-64.

29. Khan NA, Kruse JA. Methemoglobinemia induced by topical anesthesia: a case report and review. Am J Med Sci 1999;318:415-8.

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30. Gronert GA. Cardiac arrest after succinylcholine: mortality greater with rhabdomyolysis than receptor upregulation. Anesthesiology 2001;94:523-9.

31. Ely EW, Baker AM, Dunagan DP, et al. Effect on the duration of mechanical ventilation of identifying patients capable of breathing spontaneously. N Engl J Med 1996;335:1864-9.

32. Namen AM, Ely EW, Tatter SB, et al. Predictors of successful extubation in neurosurgical patients. Am J Respir Crit Care Med 2001;163:658-64.

33. Eikermann M, Blobner M, Groeben H, et al. Postoperative upper airway obstruction after recovery of the train of four ratio of the adductor pollicis muscle from neuromuscular blockade. Anesth Analg 2006;102:937-42.

34. Debaene B, Plaud B, Dilly MP, et al. Residual paralysis in the PACU after a single intubating dose of nondepolarizing muscle relaxant with an intermediate duration of action. Anesthesiology 2003;98:1042-8.

35. Pavlin EG, Holle RH, Schoene RB. Recovery of airway protection compared with ventilation in humans after paralysis with curare. Anesthesiology 1989;70:381-5.

36. Berg H, Roed J, Viby-Mogensen J, et al. Residual neuromuscular block is a risk factor for postoperative pulmonary complications. A prospective, randomised, and blinded study of postoperative pulmonary complications after atracurium, vecuronium, and pancuronium. Acta Anaesthesiol Scand 1997;41:1095-103.

37. Loudermilk EP, Hartmannsgruber M, Stoltzfus DP, et al. A prospective study of the safety of tracheal extubation using a pediatric airway exchange catheter for patients with a known difficult airway. Chest 1997;111:1660-65.

38. Gross JB, Bachenberg KL, Benumof JL, et al. Practice guidelines for the perioperative management of patients with obstructive sleep apnea: a report by the American Society of Anesthesiologists Task Force on Perioperative Management of Patients with Obstructive Sleep Apnea. Anesthesiology 2006;104:1081-93.

39. Seitz PA, Gravenstein N. Endobronchial rupture from endotracheal reintubation with an endotracheal tube guide. J Clin Anesth 1989; 1: 214-17.

40. Baraka AS. Tension pneumothorax complicating jet ventilation via a Cook airway exchange catheter. Anesthesiology 1999; 91:557-8.

41. Benumof JL. Airway exchange catheters: simple concept, potentially great dangers (editorial). Anesthesiology 1999;91:342-4.

42. Craven DE. Preventing ventilator-associated pneumonia in adults: sowing the seeds of change. Chest 2006;130:251-60.

Self-Assessment Questions1. Factors contributing to rapid oxygen desaturation during intubation in the

critically ill include:(a) increased oxygen consumption(b) anemia(c) low cardiac output(d) limited preoxygenation efficacy(e) all of the above

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2. Airway exchange catheters(a) should be fully inserted into the tracheobronchial tree during ETT exchange(b) can be utilized for proximal jet venturi support of ventilation(c) can remain in the trachea and supply supplemental O2 after extubation(d) should fit snugly through the ETT when used for difficult extubation

3. Which of the following is true regarding complications from ICU airway management?(a) The rate of DI mirrors that reported in the operating room.(b) Severe hypoxemia is associated with multiple DLs and EI.(c) Post-intubation cardiac arrest is most commonly from ventricular arrhythmias.(d) Survival to hospital discharge is extremely rare in ICU patients suffering post-intubation cardiac arrest.

Answer Key: 1. (e); 2. (c); 3. (b)

Written Didactics

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