Paediatric Anaesthesia G.K.Kumar. Gregory 4 th edition Smith 4 th edition Paediatric Anaesthesia.

Paediatric Anaesthesia

G.K.Kumar

• Gregory 4th edition• Smith 4th edition



• Introduction– Why?– What?– How?


It’s Different


It’s Different

Paediatric anaesthesia is a family affair.


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


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


•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


• Psychological preparation of child and family

• Premedication option

• Induction technique

• Intra operative considerations

• Postoperative emergence, analgesia

• Follow up


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


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.

•



• Ketamine

6 to 10 mg/kg

3 to 4 mg/kg


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


Pharmacologic premedication• Midazolam

+

• Ketamine

100% successful separation

85% easy mask induction

0.4 mg/kg + 4 mg/kg



• Fentanyl lollypops

• (oral transmucosal Fentanyl) • 15 to 20 mcg/kg• Increased volume of gastric contents • Nausea and vomiting • Pruritus

• Hypoventilation (SpO2 <90)


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


•Parental separationIt’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


• 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


•IV Access

Call for help Use gadgets

It’s Different

Induction Techniques

• Inhalational

• Intravenous (IV)

• Intramuscular (IM)

• Rectal

• Oral

http://metrohealthanesthesia.com/edu/ped/induction5.htm#inhalational

http://metrohealthanesthesia.com/edu/ped/induction4.htm#iv

http://metrohealthanesthesia.com/edu/ped/induction6.htm#im

http://metrohealthanesthesia.com/edu/ped/induction6.htm#rectal

http://metrohealthanesthesia.com/edu/ped/pedspreop6.htm#midket


‘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

=


CONSENSUS GUIDELINE ON PERIOPERATIVEFLUID MANAGEMENT IN CHILDREN 2007COTWAF-2009


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


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


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


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


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


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


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


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

Paediatric Anaesthesia G.K.Kumar. Gregory 4 th edition Smith 4 th edition Paediatric Anaesthesia.

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Transcript of Paediatric Anaesthesia G.K.Kumar. Gregory 4 th edition Smith 4 th edition Paediatric Anaesthesia.