Paediatric Anaesthesia
G.K.Kumar
• Gregory 4th edition• Smith 4th edition
Paediatric Anaesthesia
Paediatric Anaesthesia
• Introduction– Why?– What?– How?
Paediatric Anaesthesia
It’s Different
Paediatric Anaesthesia
It’s Different
Paediatric anaesthesia is a family affair.
Paediatric Anaesthesia
Not a miniature adult
• Airway difference• Changes in cardiovascular system• Chest wall/Respiratory difference• Kidney and liver difference• GI system and thermoregulation
difference• Pharmacology/dynamics difference
Paediatric AnaesthesiaIt’s Different
Paediatric Anaesthesia
Airway difference:
Large tongueEpiglottis short and stubbyHigher located larynx Angled vocal cords Narrowest portion is cricoid cartilage
It’s Different
Increased total body water:– Large initial dose required– Less fat longer clinical drugs effect– Redistribution of the drug into muscle will
increase duration of clinical effect (fentanyl)
– Consider liver and kidney immaturity
Paediatric AnaesthesiaIt’s DifferentPharmacology/dynamics
Changes in cardiovascular system
Removal of placenta from circulation Increasing of systemic vascular resistance Decreasing of pulmonary vascular resistance True closure of PDA ~ 2-3 weeks critical
transitional circulation Myocardial cell mass less developed prone to
biventricular failure, volume loading, poor tolerance to afterload, heart rate-dependent CO*
* True for young infants
Changes in pulmonary system:
Small airway diameter - increased resistance
Little support from the ribs
VO2 2x > adults
Diaphragm and intercostal muscles do not achieve type-1 adult muscle fibers until age 2
Obligate nasal breathers
Kidney and liver difference:
Low renal perfusion pressure, immature GF, TF, obligate Na loser in the 1st month of life
Complete maturation @ 2 years of age
Impaired liver enzymes, including conjugation react.
Lower levels of albumen and proteins - prone to neonatal coagulopathy, and less drug bound
higher drug levels
GI system and thermoregulation:
Full coordination of swallowing ~ 4-5 months increased risk for GE reflux
Large body surface area/weight
Limited ability to cope stress
Minimal ability to shiver in 1st 3 months
Heat whole body including the head
It’s Different
Paediatric Anaesthesia
•Different environment•Different gadgets•Different techniques
• Pre anesthetic evaluation• NPO order• Premedication• Fear of the unknown• Fear of parental separation• IV access• Anesthesia• Post anesthesia care• Post op pain relief
Paediatric AnaesthesiaIt’s Different
• Psychological preparation of child and family
• Premedication option
• Induction technique
• Intra operative considerations
• Postoperative emergence, analgesia
• Follow up
Paediatric AnaesthesiaIt’s Different
Preoperative preparation
• The number one error in paediatric anaesthesia is inadequate preparation.
• Planning prevents problems!• Absence of adequate pre-anaesthetic assessment is one
of top three causes of lawsuits against anaesthesiologists.
• Pre anesthetic evaluation
Paediatric AnaesthesiaIt’s Different
Airway? IV Access
Premedication Options
Pharmacologic premedication
• Midazolam
0.5 to 1.0 mg/kg up to 10 mg max.
0.2 to 0.6 mg/kg up to 10 mg max.
0.35 to 1.0 mg/kg
Premedication OptionsMidazolam – PO: 0.5 to 1.0 mg/kg up to 10 mg max.
• Bioavailability = 30% • Peak serum levels after about 45 minutes • Peak sedation by about 30 minutes • 85% peaceful separation • Beware: total volume of dose should probably not exceed 0.4-0.5 ml/kg (NPO!)
– Nasal: 0.2 to 0.6 mg/kg • Peak serum level in 10 minutes • 0.2 mg/kg same as 0.6 mg/kg except
– 0.2 mg/kg did not delay recovery – 0.6 mg/kg may delay extubation
– Sublingual: 0.2-0.3 mg/kg as effective as 0.2 mg/kg intranasal
– Rectal: 0.35 to 1.0 mg/kg • Some effect by 10 minutes, peak effect 20-30 minutes. • 1.0 mg/kg did not delay PACU discharge.
•
Premedication Options
Pharmacologic premedication
• Ketamine
6 to 10 mg/kg
3 to 4 mg/kg
Premedication Options
Ketamine • PO: 6 to 10 mg/kg • May slightly prolong time to discharge after a
short case• IM: 3 to 4 mg/kg sedation; • 2 mg/kg did not delay recovery • 6 to 10 mg/kg = IM induction of general
anesthesia • 10 mg/kg: as effective as Midazolam 1 mg/kg but
some delay in recovery may be expected
Premedication Options
Pharmacologic premedication• Midazolam
+
• Ketamine
100% successful separation
85% easy mask induction
0.4 mg/kg + 4 mg/kg
Premedication Options
Pharmacologic premedication
• Fentanyl lollypops
• (oral transmucosal Fentanyl) • 15 to 20 mcg/kg• Increased volume of gastric contents • Nausea and vomiting • Pruritus
• Hypoventilation (SpO2 <90)
Paediatric Anaesthesia
Avoid over sedation
It’s Different
Parental presence
• Parents and Toys-"Parents are often the best premedication."
• The presence of the parents during induction has virtually eliminated the need for sedative premedication.
• Helpful for children older than 4 years who have calm parents
Paediatric Anaesthesia
•Parental separationIt’s Different
Paediatric AnaesthesiaIt’s Different
• Early infancy (up to7 m): Parents are the primary focus. Gentle, comfortable separation is almost always possible before induction of anesthesia.
• 1 to 3 yr: Separation anxiety is major consideration. Surgery outpatient bases if possible. Careful selection regarding parental presence.
Parental separation
Paediatric AnaesthesiaIt’s Different
• 3 to 6 years: Child becomes primary focus. Fear of unknown dealt with by explaining exactly what will happen; what you will do. Then make sure you do it that way. (Be trustworthy!)
• 6 years to adolescent: Increasing involvement of patient.•
Parental separation
NPO Guidelines
• AGE MILK & SOLIDS FLUIDS• < 6 MTHS 4 HRS 2 HRS• 6-36 MTHS 6-8 HRS 3HRS• >36 MTHS 6-8 HRS 3HRS• This fasting regimen has made the preoperative fast a
much more humane process for both the patients
and the parents• BEWARE effects of STRESS & DRUGS
COTWAF-2009
Paediatric Anaesthesia
•IV Access
Call for help Use gadgets
It’s Different
Induction Techniques
• Inhalational
• Intravenous (IV)
• Intramuscular (IM)
• Rectal
• Oral
Paediatric AnaesthesiaIt’s Different
‘Try your mask’
Induction Techniques
• How old is the patient? • What is the underlying illness? General medical
condition? ASA physical status? • What is the surgical procedure planned? • How cooperative is the patient? • Will a parent be present? • Does s/he have an IV? • What are the skills and preferences of the
anaesthesiologist?
Factors Influencing Choice of Technique
Peri operative Fluid Management
Maintenance of IN & OUT
=
Peri operative Fluid Management
CONSENSUS GUIDELINE ON PERIOPERATIVEFLUID MANAGEMENT IN CHILDREN 2007COTWAF-2009
Peri operative Fluid Management
1.Children can safely be allowed clear fluids 2 hours before surgery without increasing the risk of aspiration.2. Food should normally be withheld for 6 hours prior to surgery in children aged 6 months or older.3. In children under 6 months of age it is probably safe to allow a breast milk feed up to 4 hours before surgery
APA Guidelines-2007
COTWAF-2009
Peri operative Fluid Management
4. Dehydration without signs of hypovolaemia should be corrected slowly.5. Hypovolaemia should be corrected rapidly to maintain cardiac output and organperfusion.6. In the child, a fall in blood pressure is a late sign of hypovolaemia.
APA Guidelines-2007
COTWAF-2009
Peri operative Fluid Management
7. Maintenance fluid requirements should be calculated using the formula of Holliday and SegarBody weight Daily fluid requirement0-10kg 4ml/kg/hr10-20kg 40ml/hr + 2ml/kg/hr above 10kg>20kg 60ml/hr + 1ml/kg/hr above 20kg
APA Guidelines-2007
COTWAF-2009
Peri operative Fluid Management
8. A fluid management plan for any child should address 3 key issuesi. any fluid deficit which is presentii. maintenance fluid requirementsiii. any losses due to surgery e.g. blood loss, 3rd space losses
APA Guidelines-2007
COTWAF-2009
Peri operative Fluid Management
9. During surgery all of these requirements should be managed by giving isotonicfluid in all children over 1 month of age
10. The majority of children over 1 month of age will maintain a normal blood sugarif given non-dextrose containing fluid during surgery
APA Guidelines-2007
COTWAF-2009
Peri operative Fluid Management
11.Children at risk of hypoglycaemia if non-dextrose containing fluid is given are those on parenteral nutrition or a dextrose containing solution prior to theatre,children of low body weight (<3rd centile) or having surgery of more than 3 hours duration and children having extensive regional anaesthesia. These children atrisk should be given dextrose containing solutions or have their blood glucose monitored during surgery.
APA Guidelines-2007
COTWAF-2009
Peri operative Fluid Management
APA Guidelines-2007
12. Blood loss during surgery should be replaced initially with crystalloid or colloid,and then with blood once the haematocrit has fallen to 25%. Children with cyanotic congenital heart disease and neonates may need a higher haematocrit to maintain oxygenation.
COTWAF-2009
Peri operative Fluid Management
APA Guidelines-2007
13. Fluid therapy should be monitored by daily electrolyte estimation, use of a fluidinput/output chart and daily weighing if feasible.
14. Acute dilutional hyponatraemia is a medical emergency and should be managed in PICU.
COTWAF-2009
Extubation-Always awake
Except
COTWAF-2009
Common PostoperativeProblems In Paediatric Anaesthesia
• Emergence Delirium
• Upper Airway Obstruction
• Laryngospasm
• Post Intubation Croup
• Bronchospasm
• Aspiration
COTWAF-2009
Thank youG.K.Kumar