Gas exchange

GAS EXCHANGE

GOALS FOR THIS CONCEPT PRESENTATION

1. Define and describe the concept.

2. Notice risk factors for impaired gas exchange.

3. Recognize when an individual has compromised gas exchange.

4. Provide appropriate nursing and col laborative interventions for optimizing gas exchange.

DEFINE AND DESCRIBE THE CONCEPT OF GAS EXCHANGE

DEFINITION

Gas exchange is the process by which oxygen is transported to cells and carbon dioxide is transported from cells.

OTHER KEY TERMS

Collaborative Learning #1 In your learning group, discuss the meaning of the l isted key terms and each one’s l ink to the concept definition.Ischemia

Hypoxia

Anoxia

Diffusion reduced oxygenation of arterial blood

is insuff icient f low of oxygenated blood to t issues that may result in hypoxia and subsequent cel l injury or

death.

insufficient oxygen reaching cells

the total lack of oxygen in body t issues

SCOPE OF CONCEPT

Optimal Gas

Exchange

Impaired Gas

Exchange

Absence of Gas

Exchange

Collaborative Learning #2

In your learning group, discuss the three gas exchange categories.

How they are different

How they are similar

In what ways they are dependent on one another

CATEGORIES OF GAS EXCHANGE

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Perfusion: refers to the movement of blood; oxygen-rich blood moves to the cel ls, and carbon dioxide–saturated blood moves from the

cel ls to the alveoli for el imination

Ventilation: refers to

inhalation of oxygen,

exchange of oxygen and

carbon dioxide, and exhalation of

carbon dioxide in the

lungs Transport: refers to the availabil i ty of hemoglobin ( in

the red blood cells) to carry

(transport) oxygen and carbon dioxide

as blood moves through the body

REVIEW OF RESPIRATORY SYSTEM

Upper and lower airways

Lungs

Alveol i

Capil laries

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Causes of hypoxia

examples Interventions

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SuffocationConfined in small space

High alt itudeHaving inappropriate O2 flow

rate assigned to oxygen device

Stop the cause of the suffocation and administer

oxygen

Hypoventi lation

Sleep apnea: cerebral hypoxia; drug overdose; MS, Brain tumor; ^ICP; Guil lan-

Barre Syndrome

IVIG; Octagam IV; Aubagio; Interferon; Narcan; BiPap; Chemotherapy, radiation,

surgery; Decreased blood

flow past the alveoli (usually

decreased cardiac output)

MI; hemorrhage, arrhythmias, electrolyte

imbalance, coronary thrombosis; hardening or

arteries; shock

Treatment of cause= MI-defrbri l latr ion; arrythmias-

medication; thrombosis-anti-coagulaant; arthersclerosis-

cholesterol medication; shock- f luids, O2, antibiotics; DOPAMINE;

Isuprel INJImpaired diffusion from thickening of

alveol i ’s membrane(interstit ial cystit is)

Caused by TB, RSV, RA, lupus, amiodarone, chemotherapy,

some antibiotics

Elmiron, pentosan polysulfate; dimethyl sulfoxide

Venti lation/perfusion mismatch-blood

passing unoxygenated alevoli

Fi l led with pus/infection or water- either from infection or

drowning, or CHF

Edema-lasix/diuretic; infection-antibiotics; drowning- CPR

Right to left shunt causing oxygenated and unoxygenated

blood to mix

VSD, ASD, PFO etcUsually surgical correction of

problem

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PROCESS OF GAS EXCHANGEhttps://www.youtube.com/watch?v=WXOBJEXxNEo

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CONSEQUENCES: IMPAIRED GAS EXCHANGE

Impairment of gas exchange occurs when the diffusion of gases (oxygen and carbon dioxide) becomes impaired because of

Ineffective ventilation Reduced capacity for gas transportation (reduced hemoglobin and/or red blood cells) Inadequate perfusion

CONSEQUENCE OF SEVERE, UNRESOLVED IMPAIRMENT IN GAS EXCHANGE

NOTICE RISK FACTORS FOR IMPAIRED GAS EXCHANGE

RISK FACTORS: POPULATIONS AT GREATEST RISKCollaborative Learning #3

In your learning group, discuss why the following patient groups are considered the populations at greatest r isk:

Infants

Children

Older adults

INDIVIDUAL RISK FACTORS

Age

Smoking

Presence of chronic medical conditions, such as chronic obstructive pulmonary disease (COPD), cystic f ibrosis (CF), Heart Failure (HF)

Immunosuppression

Reduced state of cognition

Brain injury

Prolonged immobil ity

RECOGNIZE WHEN AN INDIVIDUAL HAS COMPROMISED GAS EXCHANGE

ELEMENTS OF RESPIRATORY ASSESSMENTHISTORY

Past medical history

Family history

Current medications

Lifestyle behaviors

Occupation

Social environment

Problem-based history

EXAMINATION

Vital signs Heart rate, respiratory rate, blood

pressure, temperature, oxygen saturation

Inspection Breathing effort Skin color Thorax Extremities

Auscultation of lung sounds

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COMMON DIAGNOSTIC TESTS

Laboratory tests Arterial blood gases, complete blood count, sputum, biopsy

Radiologic studies Chest x-ray, CT and MRI scans, ventilation/perfusion (V/Q) scan, positron emission

tomography (PET) scan

Pulmonary function studies

Endoscopy

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RBC count Adult/elderly Male: 4.7-6.1; Female: 4.2-5.4; Children Newborn: 4.8-7.1 2-8 weeks; 4.0-6.0; 2-6 months: 3.5-5.5; 6 months-1 year: 3.5-5.2; 1-6 years: 4.0-5.5; 6-18 years: 4.0-5.5

Hemoglobin Male: 14-18 g/dL or 8.7-11.2 mmol/L (SI units); Female: 12-16 g/dL or 7.4-9.9 mmol/L (SI units); Pregnant female: >11 g/dL; Elderly: values are slightly decreased; Children Newborn: 14-24 g/dL; 0-2 weeks: 12-20 g/dL; 2-6 months: 10-17 g/dL; 6 months–1 year: 9.5-14 g/dL; 1-6 years: 9.5-14 g/dL; 6-18 years: 10-15.5 g/dL

<5.0 g/dL or >20 g/dL

Hematocrit Male: 42%-52% or 0.42-0.52 volume fraction (SI units); Female: 37%-47% or 0.37-0.47 volume fraction (SI units); Pregnant female:

>33%; Elderly: values may be slightly decreased; Children (Newborn: 44-64; 2-8 weeks: 39-5; 2-6 months: 35-50; 6 months–

1 year: 29-43; 1-6 years: 30-40; 6-18 years: 32-44

<15% or >60%

Red blood cell indices Mean corpuscular volume (MCV); Adult/elderly/child: 80-95 fL Newborn: 96-108 fL Mean corpuscular hemoglobin (MCH)Adult/elderly/child: 27-31 pg Newborn: 32-34 pg Mean corpuscular hemoglobin concentration (MCHC), Adult/elderly/child: 32-36 g/dL (or 32%-36%) Newborn: 32-33 g/dL (or 32%-33%) ,Red blood cell distribution width (RDW), Adult: 11%-14.5%

WBC Adult/child >2 years: 5000-10,000/mm3 or 5-10 × 109/L (SI units) ;Child ≤2 years: 6200-17,000/mm3 ;Newborn: 9000-30,000/mm3

WBCs <2500 or >30,000/mm3

Neutrophils:% 55-70/ absolute 2500-8000  

  Lymphocytes %20-40/ Absolute 1000-4000  

Monocytes %2-8/ Absolute 100-700  

Eosinophils % 1-4/ Absolute 50-500  

Basophils% 0.5-1/ Absolute 25-10  

Platelet count(Thrombocyte count)

Normal findingsAdult/elderly: 150,000-400,000/mm3 or 150-400 × 109/L (SI units) ;Premature infant: 100,000-300,000/mm3; Newborn: 150,000-300,000/mm3 ;Infant: 200,000-475,000/mm3 ;Child: 150,000-400,000/mm3

<50,000 or >1 million/mm3

PROVIDE APPROPRIATE NURSING AND COLLABORATIVE INTERVENTIONS TO OPTIMIZE PERFUSION

CLINICAL MANAGEMENT: PRIMARY PREVENTIONInfection control

Smoking cessation

Immunizations

Preventing postoperative complications

CLINICAL MANAGEMENT: COLLABORATIVE INTERVENTIONSTreatment strategies depend on the underlying condit ion and the age of

the patient For each intervention, how does age affect safe and effective delivery of care?

CLINICAL MANAGEMENT:COLLABORATIVE INTERVENTIONS (CONT’D)Smoking cessation

Pharmacotherapy Types of drugs Medication administration

Nutrit ion therapy

Posit ioning

Chest physiotherapy

Postural drainage

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Postural drainage is getting in positions that make it easier for mucus to drain. Chest physiotherapy is gently "clapping" parts of the body to remove mucus from the lungs. They are often used together in conditions such as cystic fibrosis or a spinal cord injury (SCI) to help loosen and remove mucus from the lungs. When mucus collects in your lungs, it increases your risk for lung infections, such aspneumonia.Following are general instructions for chest physiotherapy and postural drainage. Talk to your doctor about the positions you should use and how long how to do it.•Be sure your back is covered. Wear a shirt or blouse, or cover your back with a towel.•Hold each position for 5 minutes to help the mucus drain from your lungs.•For each position, your caregiver claps your back quickly and rhythmically. Your caregiver bends his or her hand at the knuckles to form a cup. The arrows and ovals in the above illustrations show where to clap.•When your caregiver claps, you should hear a hollow sound. If you hear a slapping, the hand is not cupped enough.•Do not clap over the spine.Morning is the best time to do postural drainage, because it helps clear mucus that has built up during the night. It may also be done just before bed to decrease nighttime coughing. Do not do it soon after a meal, because this may increase the chance of vomiting.

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Percussion and vibration may be performed in conjunction with segmental expansion. Percussion is the rhythmic clapping with cupped hands over the involved lung segment performed throughout the respiratory cycle, with the goal of mechanically dislodging pulmonary secretions. Vibration is performed by creating a fine oscillating movement of the hands on the chest wall just before expiration begins and throughout the expiration phase. If the child does not tolerate percussion and vibration, placing the patient in side lying and gently rocking back and forth may stimulate expansion, secretion motion and relaxation. This technique is affective if the child is upset and may decrease respiratory rate. Positioning may be useful for patients, but certain positions may be contraindicated post thoracic surgery. Check with the MD or nurse before using positioning to make sure that it is safe for the child.

CLINICAL MANAGEMENT:COLLABORATIVE INTERVENTIONS (CONT’D) Oxygen therapy devices

Airway suctioning

Endotracheal tubes and tracheostomy tubes

Mechanical intubation

Chest tube management

INHALATION THERAPYNasal Cannula Pediatric: .5 – 4 l iters

per minute (lpm) /Infant: .25 – 2 lpm

Simple Mask Pediatric: 6 – 10 lpm/ Infant: 5 – 8 lpm

Partial Rebreather 10 – 12 lpm

Venture Mask Liter f low indicated for specific FiO2

Non- Rebreather Mask 10 – 15 lpm

Aerosol 8 – 12 lpm

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Oxygen tents and hoods are usually used for pediatric patients who have airway inflammation, croup, or other respiratory infections. The oxygen tent consists of a canopy that surrounds the child. It provides oxygen, humidification, and a cool environment to help control body temperature. The oxygen hood consists of a disposable vinyl box that fits over the child’s head. It provides warm humidified oxygen at a specific temperature. When using a hood, it is important to ensure that there is enough space between the curve of the hood and the child’s neck to allow carbon dioxide to escape.An oxygen hood delivers a 28% to 85% oxygen concentration varying with the flow rate, which can be set at 5 to 12 L/min. An oxygen tent can provide oxygen concentrations of up to 50% with flow rates from 10 to 15 L/min

http://www.atitesting.com/ati_next_gen/skillsmodules/content/oxygen-therapy/equipment/delivery-devices.html

OXYGEN DELIVERY SYSTEMHTTP://WWW.RCJOURNAL.COM/CPGS/SODDNPPCPG-UPDATE.HTML

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O2 concentrations may vary within the hood.O2 concentrations should be measured as near the nose and mouth as possible. Opening any enclosure decreases the O2 concentration. For infants and children confined to hoods, nasal O2 may need to be supplied during feeding and nursing care. Flows > 7 L/min are required to wash out CO2.Devices can be confining and isolating. Concentration in a hood can be varied from Temperature of the gases in the hood should be maintained to provide a neutral thermal environment. High gas flows may produce harmful noise levels. Hoods and transparent enclosures: Prolonged exposure to humidified oxygen may increase risk for cutaneous fungal infection. Inadequate or loss of gas flow may result in hypoxia or hypercapnia. 6.2.6.3 Use of an improperly sized hood can result in irritation of the infant's skin

A simple mask is usually used for patients who require a moderate flow rate for a short period of time. It is composed of a plastic mask that fits snugly over the patient’s mouth and nose. The mask has holes on each side that are used for exhalation and for air entrainment if the flow rate is too low. An adjustable elastic strap that fits over the patient’s head holds the mask in place. A piece of tubing connects the mask to the oxygen source. Extension tubing is usually added to allow the patient more freedom of movement.A simple mask has the ability to deliver oxygen concentrations of 40% to 60% with flow rates from 6 to 10 L/min. Because carbon dioxide can build up in the mask at low flow rates, do not use a flow rate lower than 6 L/min with this type of mask. When using this mask, consider humidification to keep the patients’ mucous membranes from becoming dry.

A nasal cannula is the device most often used to administer oxygen therapy. It consists of a length of tubing, usually 7 to 14 feet long, with two small prongs to insert into one of the patient’s nares. It also has a plastic piece at the neck that slides up under the patient’s chin to tighten the tubing and keep it in place. It is available in a range of sizes and can be used for various age groups.A nasal cannula delivers oxygen concentrations of 22% to 50% with flow rates from 1 to 6 L/min through the cannula. The exact concentration inspired depends on the flow rate and on the patient’s rate and pattern of breathing and the depth of respirations. A nasal cannula is usually used for patients who are noncritical with minor breathing problems and for patients who cannot or will not wear an oxygen mask. Because this device administers low-flow oxygen, humidification is rarely required

http://www.bing.com/videos/search?q=how+to+inflate+a+non-rebreather+mask&FORM=HDRSC3#view=detail&mid=3A8A64E2A0CBE35DDBF13A8A64E2A0CBE35DDBF1

Another type of device used for oxygen therapy is a nonrebreather mask. This device is used to deliver high flow rates and high concentrations of oxygen. Like the simple mask, the nonrebreather mask fits snugly over the patient’s mouth and nose. An adjustable elastic strap that fits over the patient’s head holds the mask in place.A nonrebreather mask has ports on each side that have one-way valves that keep the patient from breathing in room air to ensure that a high concentration of oxygen is delivered. The mask also has a reservoir bag that is inflated with pure oxygen. Between the mask and the bag is another one-way valve that allows the patient to breathe in the oxygen supplied by the source as well as oxygen from the reservoir. This provides the patient with an oxygen concentration of nearly 100%. A piece of tubing, usually connected to extension tubing, connects the mask to the oxygen source.A nonrebreather mask can deliver oxygen concentrations of 60% to 95% with flow rates from 10 to 15 L/min. When using a nonrebreather mask, do not allow the reservoir bag to deflate. If it does deflate, the patient is likely to breathe in large amounts of exhaled carbon dioxide.

MONITORING OXYGEN LEVELS

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Suctioning infants and children requires the use of smaller suction catheters and lower suction pressures than for adults. Catheter sizes range from 5 Fr to 14 Fr,

with smaller sizes used for smaller tubes. To avoid total airway occlusion, catheter

size should be approximately half the inner diameter of the tracheostomy tube.

Recommended pressures for tracheostomy suctioning vary by age

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It is important to preoxygenate in children before and after suctioningHave the child on a pulse ox and stop the procedure if the child falls below parameters (usually 90%) Nasopharyngeal (without applying suction): In adults insert catheter about 16 cm (6.4 inches); in older children, 8 to 12 cm (3 to 5 inches); in infants and young children, 4 to 7.5 cm (1.6 to 3 inches). Rule of thumb is to insert catheter distance from tip of nose (or mouth) to angle of mandible.

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Neonates and infants: 60 to 80 mm Hg•Children: 80 to 100 mm Hg•Adolescents: 80 to 120 mm H

Nasotracheal (without applying suction): In adults insert catheter about 20 cm (8 inches);in older children about 16 to 20 cm (6 to 8 inches); and in young children and infants, 8 to 14 cm (3 to 5 ½  inches)Predicted Size Uncuffed Tube = (Age / 4) + 4Predicted Size Cuffed Tube = (Age / 4) + 3

EXEMPLARS

Think about common examples of impaired gas exchange. How do these vary according to the age of the patient?

Infants

Young children

Adolescents

Adults

Older adults