125 slides about the updated topic in pediatric anesthesia,and laparoscopy in pediatrics

1. Pediatric anesthesia
The Basics and Beyond
Ahmad Abou Leila MD
Dr.Roland Kaddoum

2. Presentation facts and objectives
125 slides(72+53)
REVIEW the Peds anesthesia basics
Updated Basics
Some of the SVI mission in Egypt

3. Infants are not small adults

4. Different Anatomy
Different Physiology
Different Pharmacology
Different psychology

6. Different Approach and preparation
Better understanding of peds
anesthesia principles

7. The different Physiology

8. Limited blood volume
80ml/kg(full term)
Limited stroke volume

9. CO=SV x HR

10. CO=SV x HR
High Heart Rate to maintain CO

11. The parasympathetic system is mature in newborns
Dominant
Vagotonic
50% of apparently healthy babies
24 hours EKG recording
Have shown rhythm changes resembles complete 2:1 Block

12. Anything causes bradycardia
Hypoxia,hypothermia,laryncoscopy
Affect the CO

13. Pediatric Fundamentals – Heart and Circulation
Normal heart rate
Age (days) Rate
1-3 100-140
4-7 80-145
8-15 110-165
Age (months) Rate
0-1 100-180
1-3 110-180
3-12 100-180
Age (years) Rate
1-3 100-180
3-5 60-150
5-9 60-130
9-12 50-110
12-16 50-100

14. HIGH HR……..Risk of fatigue
compensation
LOW afterload

15. Lowest acceptable SBP=70 + (age x2)

16. CO can be assessed clinically by stethoscope
Heart sounds become softer and muffled in low CO states

20. Contractile element is 30%
(60%in adults)
Starling law is at maximum
Cannot tolerate volume overload

21. Thin wall atria and ventricle
Risk of tamponade during central line
insertion

22. Born T wave upright in all chest leads
In few hours T wave isoelectric or
inverted in left chest
In 7 days T wave inverted in the Right
chest leads (V1-V4)
Failure of T wave inversion in V1-V4 is
the earliest sign of RV hypertrophy

23. Respiratory System

24. Almost all cardiac arrest due to
respiratory problem

25. Limited AP expansion
Limited Lateral expansion
Ventilation depend on the
Diaphragm

26. Diaphragm in neonates and
infants<2y
easy fatigue
(lacks the Type I muscle fibers )

27. Any restriction of the Diaphragm movement
Results in respiratory difficulties
stomach inflation due to forceful inflation
will hinder ventilation

28. High Risk of barotrauma on MV -PCV

29. Small lung volume relative to their body size
Small FRC
High RR to maintain the FRC
High RR on MV

30. Under general anesthesia, FRC declines by
10-25% in healthy adults
35-45% in 6 to 18 year-olds

31. General anesthesia, FRC and PEEP
PEEP
important in children < 3 years
essential in infants < 9 months
Mean PEEP to resore FRC to normal
infants < 6 months 6 cm H2O
children 6-12 cm H2O

33. Higher O2 Consumption
6ml-7ml/kg
Adults (3-4ml/kg)
rapid desaturation

34. Aspiration Risk
Children < 3 years at greater risk of aspiration

35. No muscle
Higher
relaxants
incidence of
Inadequate
GERD
anesthesia
Short
esophagus
Limited Excessive air
stomach swallowing
compliance during crying
Baby trust

36. 4 hours
6 hours
8 hours

37. Encourage water intake within two hours

39. Less dehydration
(better induction
hemodynamic profile)
Less agitation and crying
Promotes motility
Decrease gastric volume

40. Neonatal period the HB is HBF
HBF has high affinity to O2 ……P50 is ………

41. HBF decline with age
HBA peaks at 9 month

42. O2 dissociation curve shifts to the right by acidosis(more delivery)
O2 dissociation curve shifts to the left by alkalosis (less delivery)

43. MV in neonates avoid the hyperventilation induced alkalosis

44. P50 Hgb for equivalent tissue oxygen delivery
Adult 27 8 10 12
> 3 months 30 6.5 8.2 9.8
< 2 months 24 11.7 14.7 17.6

45. Implications for blood transfusion
older infants may tolerate somewhat lower Hgb levels at which
neonates ought certainly be transfused

46. Maximal allowable blood loss MABL: EBV x (Hcti-Hctf)/averaage Hct

47. Neonates have immature WBCs function ..risk of infection is high

48. Vitamin k dependent factors(II,VII,IX,X)
20-60% of adult values
Infants of mother who have received
anticoagulation may develop severe bleeding like
Vitamin K deficiency
Babies on MV showed significant thrombocytopenia

49. Large surface area relative to body weight(2-2.5x BW)
Thin skin and subcutaneous fat( less insulation)
Neonates no shivering
Immature thermoregulation center

50. Forced air warming systems always available
Fluid warmer
Room temperature

54. Infant kidneys
immature function at birth:
 GFR (‘til 2 years old)
 concentrating capacity
 Na reabsorption
 HCO3 /H exchange
 free H2O clearance
 urinary loss of K+, Cl-

55. What it means:
Newborn kidney has limited
capacity to compensate for
volume excess or
volume depletion

56. Maintenance Fluid Therapy
Term Newborn (ml/kg/day)
Day 1 50-60 D10W
Day 2 100 D10 1/2 NS
>Day 7 100-150 D5-D10 1/4 NS
Older Child: 4-2-1 rule

57. Hourly Maintenance Fluids
4:2:1 Rule
4 ml/kg/hr 1st 10 kg +
2 ml/kg/hr 2nd 10 kg +
1 ml/kg/hr for each kg > 20

58. Rules 1
Always Use volumetric Chambers or
Microdrip
(infusion pumps may continue to infuse
through dislodged catheters with out alarm)

60. Rule 2
Warm up all infused fluid
Crystalloids safe up to 54 C
Blood safe up to 42 C..risk of hemolysis)

61. Rule 3
Include dextrose in the maintenance hydration
fluid (Dextrose 1% or Dextrose 2.5%)
Risk of Hypoglycemia is higher in
Premature
Sick babies(malnutrition,cardiac)
Regional anesthesia
Glucose infusion

62. hypoglycemia
Apnea
Cyanosis
Respiratory distress
Limpness
Sweating
Seizures

63. Rule 4
Replace Deficits,losses, and bleeding by
isotonic fluid (not glucose containing
fluid)
Risks of Hyperglycemia

64. Rule 5
Monitor intravascular volume closely by
BP
UOP
SVV
Heart sounds
Warm extremities
Capillary refill

65. Rule 6
Montior electrolytes closely
Risk of Hyponatremia..Na losers
Risk of hyperkalemia ..
blood transfusion
>1-2ml/kg/min

66. Different anatomy

67. Short distance between tongue and
the glottis
Tongue easily obstruct the airway
Proximity of tongue to glottis
visualization more difficult
more angulation between the oral
axis and the laryngeal axis
Straight blade preferred more
effectively in tongue lift

68. Epiglottis axis acute angle with airway axis..more
difficult to lift
Stiff
Omega shape ,touch the soft palate(easy airway
obstruction)

69. Large occiput (flexed head)
Till one year

70. Shoulder Roll
(deflex the head + stabilize the head)
Extreme extension will cause obstruction
Head parallel to the ceiling

71. The narrowest area is…………………………….

72. MRI at level of cricoid cartilage (not
MRI of sub vocal cords area
ring)

73. Bronchoscopy of glottis area
and sub glottis Bronchoscopy of cricoid cartilage

74. Abide to the rules of ideal tube
selection
Tube Size
Age(yrs)/4 +4(un cuffed)
for cuffed tube
Age(yrs)/4 +3.5

76. Subvocal cords area is the narrowest
Don’t push the tube through tight glottis opening
Prepare smaller tube size

77. un-Cuffed
Cuffed

78. Radiologic evidence
Airway is oval not circular
Clinical evidence
No difference in incidence of post intubation croup
No complications in cuffed tube

79. Cuffed tubes can be used in kids< 8 years

80. Neonates have reduced incidence of
subglottic stenosis
Immature cartilage
High water content in cartilage
Less susceptible for ischemic injuries

81. Short Neck
Short trachea
Risk of endobronchial Intubation

82. Airway management
Depth of insertion
Age/2 + 12
Age (yrs) + 10

83. Depth of insertion
One study used CXR to confirm the correct placement of
tube
The foot length was accurate as weight based formulas
Tube size X 3

84. Other uses of Tube size
Tube size
2 X Tube size=size of NG tube
3 X Tube size =Depth of tube insertion
4 X Tube size =size of chest tube

85. Intubation using Left molar approach

86. 1. Left-molar Approach Improves the Laryngeal View in Patients with
Difficult LaryngoscopyAnesthesiology. 2000 Jan;92(1):70-4 Full Text
2. Comparative Study Of Molar Approaches Of Laryngoscopy Using
Macintosh Versus Flexitip BladeThe Internet Journal of Anesthesiology 2007 : Volume 12
Number 1
3. The use of the left-molar approach for direct laryngoscopy combined
with a gum-elastic bougieEuropean Journal of Emergency Medicine December 2010
;17(6):355-356

87. Another anatomical difference
Spinal cord ends at L3
In adults it ends at……..
Be cautious in neuroaxial anesthesia
Lumbar puncture

88. Epidural or caudal block LOR with saline
LOR with air not recommended

89. Pharmacological difference

90. More free fraction of medication
Greater effect Water soluble Drugs will distribute more
Drugs high protein bound Higher loading dose to achieve desired serum
Altered protein binding
Barbiturates levels
High Volume of Distribution
Bupivacaine Muscle relaxants
Alfentanil Antibiotics
Lidocaine
Drugs that redistribute to fat
Have larger initial peak levels (Opioids)
Small proportion of fat and muscles Immaturemetabolism and excretion
Delayed Kidney and liver functions
Less muscle mass (more sensitive to muscle
relaxants)

91. Inhalation agents

92. MAC
HIGHER MAC
Highest MAC in infants 6 months and
1 year

95. Fast induction

96. Greater Alveolar High cardiac out
Reduced tissue
ventilation to FRC put to vessel rich
blood solubility
ratio organs(brain)
Fast inhalation induction

97. SEVOFLURANE
HALOTHANE
ISOFLURANE
DESFLURANE
97

100. When to intubate?

102. Pediatric psychology
Pediatric Perioperative
anxiety

103. 40%-60% of infants experience
perioperative anxiety
Highest incidence 1-5 years

105. Consequences
Bad dreams, wake up crying or walking
Disobeying parents
New onset enuresis

107. Crying leads to aerophagia and then stomach inflation
Higher risk of aspiration and inefficient ventilation

108. Parental presence induction
anesthesia(PPIA)
To date the experimental evidence doesn’t
support the routine use of PPIA

109. Pharmacologic intervention superior to
other intervention
Parent are less anxious

110. Midazolam is most commonly used(85%)
0.5mg/kg PO is the best dose(less side effects , and rapid
onset)

111. Impulsive children shows paradoxical
response to Midazolam

112. Early infancy (neonate to about 7 months of age):
Parents are the primary focus
Comfortable separation in preop holding area usual

113. Later infancy to about 5 years:
Separation anxiety major
Selected parental presence
Midazolam 0.5 mg/kg orally 10 min before separation

114. >6 years: Child becomes primary focus.
Explain exactly what will happen; what you will do
Then do it that way. (Be trustworthy!)

117. Less insufflation pressure
6mmHg for infants
12mmHg for children

118. Abdomen insufflation causes vagal stimulation

119. Abdomen insufflation with Cold CO2
Increase the risk of hypothermia

120. Abdomen insufflation
Trend position
Higher risk of endobronchial intubation

121. Higher risk of Hypovolemia
Longer time for bleeding control

122. Indication for Cuffed ET tube
Higher risk of aspiration
Accurate CO2 sampling

123. Infants < 5 kg
Peri-umbilical area shouldn’t be used for port access
Risk of umbilical artery injury

124. This lecture is posted on
www.anesthesia-resident.blogspot.com

126. Thank you all
And have a nice day