Paediatric Anaesthesia Flashcards
The provision of safe anaesthesia for the paediatric patient requires a clear understanding of the ________,________,__________ and __________ differences children and adults.
psychological, anatomic, physiological and pharmacologic
Span from Newborn to adolescent
Neonates –__________ of life. May be preterm
Infants – ______ to _________
Preschool -__-____yrs
Schoolage – ___-____ yrs
first 28 days
1 month to 1 year
1-5
5-12
Neonates further classified as
Full term
Pre-term <____wks
Extreme preterm <____ wks
Post-term >____ wks
Low Birth Weight < ____g
Extremely Low Birth Weight <______g
37
28
41
2500
1000
Postconceptual age = ______ + _______
GA + PNA
Anatomical differences
Anatomy of airway predisposes to obstruction and difficult intubation.
- ________ head, ________ neck, ________ neck muscles, ___ AP diameter→ difficult positioning.
- ________ nares → easily obstructed e.g ________ - ________ tongue readily obstructs ________ → obligate _____________
- Anterior, high larynx C___- C___
- (short or long?), ___-shaped epiglottis at _____ angle
large ; short ;underdev
↑; Small ;catarrah
large ;oropharynx ; nasal breathers
C2- C4
long ; U ; 450
Pediatric
_______ shaped larynx with ______ as the narrowest part
The ________ is narrowest part in adults
Funnel; cricoid
glottis
(Anterior or Posterior?) , (low or high?) larynx C___- C__ (C__- C__ in adults)
(Short or Long?), _____ epiglottis
Soft tracheal cartilages
Thin lining of airway which easily gets damaged.
Anterior ; Hugh
C2- C4
C5- C6
Long; floppy
Paeds
(Vertical or Horizontal?) ribs with loss of ____________ movt does not contribute to resp mechanics→ _________ breathers
Large liver pushes up and flattens diaphragm → ________ tidal volume
____________ intercostal muscles
___________________ of bronchi -___0
Horizontal ; bucket-handle
diaphragmatic ; fixed
Poorly developed
Equal bifurcation
55
Anatomical differences
CNS
Spinal cord terminates at _______
Dural sac terminates at _____ in neonates
CVS
_____ veins, extensive _________→ ________ cannulation
L3/L4
S3
Tiny; subcut fat
difficult
Physiological differences
Few alveoli → _______
↓FRC, closing volume encroaches on FRC
→ easily ________ with ____
↑alveolar ventilation will req ↑ ________________ 6-8ml/kg/min to meet demands
Response to hypercapnia and hypoxaemia →____________
Surfactant produced at ____wks GA
V/Q mismatch
hypoxic with apnoea
O2 consumption
respiratory depression
36
Physiological Cardiovascular
Easily reverts to _______ circulation
↑ cardiac output ←↑_____ reqs ↑ ________
↓ myocardial contractile tissue→ less able to ↑ ___________. Thus Cardiac output is _________ dependent
Normal heart rate – _____-_____ bts/min (neonates)
Predominant _______ innervation of heart ↓ ____- activity → _______ and _______
foetal ; BMR ; perfusion
stroke volume ; heart rate
130 -160
parasym ; sym
low BP ; PVR
Haematological
Blood volume
– preterm ____-____ mls/kg
- neonate – ____mls/kg
- infant - ____mls/kg
- child - ___mls/kg
Hb ____ – ___ g/dl at birth
- ‘physiological anaemia’
Hb____ predominant till ________ . ↓2,3 DPG, Lt shift of ODC
preterm 95 -100 mls/kg
- neonate – 90mls/kg
- infant - 85mls/kg
- child - 80mls/kg
Hb 18 – 21 g/dl at birth
HbF predominant till 6 months
Pardiatric Neonate
(Mature or Immature?) CNS
___________ myelination →_____ conduction time but _______ interneuron distance for impulse to travel
Blood-brain barrier is (more or less?) permeable
Impaired autoregulation → intraventricular hmg
Immature
Incomplete; slower
shorter; more
Paeds Temperature Control
High ______ area : _______ ratio → _____ loose heat esp from _______
Immature __________ centre
Lack of ___________
Unable to ________
Cutaneous vessels do not _________
Non-shivering thermogenesis → hypoxia, acidosis, hypoglycaemia
Thermoneutral temperature (____oC prems, ____oC neonates)
body surface area : body weight
rapidly ; head
thermoregulatory ; subcutaneous fat
shiver ; vasoconstrict
34oC ; 32oC
Paeds Renal /Fluid Balance/ Hepatic
TBW = _____% of body wt
↑ ECF (75%) →↑__________ of drugs
→ more accessible to _______
________ renal function, therefore unable to
handle large fluid or Na loads.
Limited ____________________ → easily become hypoglycaemic
90
volume of distribution; fluid losses
Immature; carbohydrate stores
Paeds pharmacology
↑ cardiac output → faster ____________
↑ ECF → ↑__________________ of highly
ionised drugs e.g muscle relaxants
Immature liver enzymes → ↓ _______________ especially __________
Immature renal fxn → ↓_____________
MAC – ___es with ____ing age till ____/12 (except _____)
↑ sensitivity to induction agents – immature ________
MR - ↑sensitivity, but ↑ vol of distr → dose
circulation time
vol of distribution ; drug metabolism
morphine; drug excretion
↑; ↑; 6; Sevo; BBB
Most anatomical and physiological differences approach adult characteristics by age _________ yrs.
8 – 10
Neonatal surgery and anaesthesia should be performed in specialized centres
T/F
T
In paeds, ______ metabolic rate & ______ resp physiology make desaturation and hypoxia more likely
They are (more or less?) able to tolerate changes in temp, glucose homeostasis
Higher; immature
Less
Pre-op assessment
Should include meeting with _______
PCA – problems of prematurity
Newborn -Congenital abnormalities, metab disturbances
Presch/ sch age – URTI, enlarged adenoids, tonsils
Immunisation
PMH – Asthma, SCD General exam
Investigate all heart murmurs
parents
Formula to estimate weight from age
0-12 month
1-5 years
6-12 year
(0.5 x months )+4
(2 x years )+8
(3 x years )+7
Preperation & premedication
Allay anxiety in parents/patient
familiarisation tour of hospital and equipments
Crossmatch blood
_________ or __________ for venepuncture
Preop fasting guidelines- avoid prolonged fast
- clear fluid –____ hrs
- breast milk –___hrs
- formula milk / solid food–____ hrs
EMLA or ametop cream
2; 4 ; 6
Suitability for Daycase
Very (good or bad?) candidates for day case surgery
Selection criteria as for adults
Good
Suitability for Daycase
Exclusion includes –
- Former preterm PCA <_____ weeks
- Undiagnosed ________
-_________ dx
- Sleep apnoea
60
cardiac murmur
Sickle cell
The child with RTI
Children prone to URTI. Many are benign and non-infectious
Important to identify those with significant RTI → _______,________,________
Severe if –________ cough, _______ nasal discharge, fever malaise,_________ , ↑ _______
Postpone till _____ wks after resolution of URTI or _____ weeks after LRTI.
Caution in infants
laryngospasm, brochospasm, atelectasis.
productive; purulent; bronchospasm; WCC
2; 4
Conduct of Anaesthesia
________ anaesthesia ± _______ technique
__________ as sole anaes techniq is
contraindicated in paeds.
Exception –______ anaes for prems
-___________ for moribund patients
General
regional
Regional
spinal; local infiltration
Induction
Calculate drug doses, blood volume and fluid req before anaesthesia
? Parental presence
________ techniques
? Anticholinergic –______,________
Inhalational -_______ or ————
IV induction – ________,_________, or ________
IM –________ especially for difficult venous access
Rectal – _________,__________. Irreg absorp
Distraction
atropine, glycopyrrolate
halothane or sevoflurane
propofol, thiopentone or ketamine
ketamine
thiopentone, methohexitone
Airway mx
Airway complications are common
Head tilt, chin-lift, jaw thurst
Position – ______,______
Intubation – _______,_________ blade
- deep inhalational, relaxant Tube
neutral, sniffing
curved, straight
Airway management
– size =___________
- length = _______________
- non-cuffed if age < ____ yrs-tube mandatory in newborn -#3, 3.5 #2.5 (prems)
– size = (age/4) + 4
- length = age/2 + 12 (or 15)
- non-cuffed if age < 8 yrs
-tube mandatory in newborn -#3, 3.5 #2.5 (prems)
Airway
LMA- size ___-___
Meticulous attention to fixing of tube
1-3
Ventilation
Spontaneous ventilation
IPPV -–__________ tube with audible____ to prevent ______________ (<10 yrs)
uncuffed; leak
subglottic stenosis
Ventilation
Equipment
-________________ face masks
- reduced _________ and good anatomical fit
-___________ breathing system – up to ___kg
-_________ system - ____ kg
-_______ circuit -_____kg
Rendell-Baker-Soucek
dead space
Mapleson F ; 25
Paed circle; >5
Bain’s; >25
Maintenance
Relaxants –_________ _-__mg/kg
- NDMR - ↑ ________
Inhalational + N2O/ Air + O2
TIVA –_______ (> ___yrs), _______
Suxamethonium; 1-2
sensitivity
Propofol; 3 ; ketamine
Monitoring
________/______ stethoscope
BP, ECG, pulse oximetry, capnography Temp, bld loss, U/O
Constant _____
Precordial / oeso
observation
Analgesia in paeds
Should not _____________
Combine regional / local with GA to ↓ need for __________
Fentanyl 1-2mcg/kg, morphine 0.1mg/kg, pethidine 1mg/kg
Caution with _________ in infants < ___________
LAA – cau block
depress resp sys
peri-op opioids
NSAIDS; 6 mths
Temperature control
Compromise between thermo-neutral temp (____prem, ____ neonates, ___ adolescent) and comfortable ambient temp (____o C)
↑ ambient temp
Wrap esp _______, radiant heater, warming blanket
Warm fluids and blood
Humidify gases
34; 33; 30; 25
head
Reversal
Reverse NMB – __________ + __________ / __________
Pharyngeal toileting
Extubate neonates that are __________, _______thermic, _______glycaemic, _______tensive and breathing __________
Awake / deep extubation.
neostigmine + atropine / glyco
fully awake
normothermic
normoglycaemic
normotensive
spontaneously
Regional Anaesthesia
Not used as sole anaesthetic tech in children <____ yrs.
_____ /______ – pre-terms and ex-prems
12
Spinal; caudal
Regional anaesthesia
Spinal/caudal – ________ and ________
- ↓ incidence of _________,————-
- less ____________ to _____________
pre-terms and ex-prems
post-op apnoea, bradycardia
disruptive to feeding regimen
POST-OPERATIVE
Positioning – airway patency, prevent _______
Supplementary oxygen till ___________
Keep warm
Monitoring
Fluid therapy
Post-op __________ – Pain scores -PCA(>____yrs) or NCA
Commence oral feeds as soon as possible
aspiration; fully awake
analgesia
5
Postoperative Analgesia
Analgesia – Opioids – morphine, pentazocine
- NSAIDS – only >________
- Paracetamol – IV, oral, rectal - PCA, NCA
Regional anaesthesia, nerve blocks, local infiltration
May require anti-emetics – ondansetron, dexamethasone
6 months
