This document discusses neonatal surgical emergencies and anesthetic management considerations. It covers the physiological differences of the neonatal system including the cardiovascular, respiratory, renal and thermal regulation systems. It emphasizes the importance of maintaining normothermia, oxygenation, hydration and glucose levels. The document provides guidance on optimization, monitoring, induction, intubation, maintenance and recovery for neonatal anesthesia. Special attention is needed in the postoperative period to prevent complications like apnea, laryngospasm and cardiac arrest.

1. NEONATAL SURGICAL
EMERGENCIES & ANAESTHETIC
MANAGEMENT
Dr.Narasimha Reddy, M.D.,DA
Professor & H.O.D,
Dept. of Anaesthesiology,
Kurnool Medical College ,
Kurnool

2. PART I
PHYSIOLOGICAL
CONSIDERATIONS
&
ANAESTHETIC
IMPLICATIONS

3. • Neonatal surgical emergencies are common
in developing countries.
– High birth rate
– Consanguinity
– Infections during pregnancy
– Multiple pregnancies
– malnutrition

4. Some terminologies:
• Fetus: intrauterine period
• Newborn: upto 12 hrs after birth
• Neonate: upto 30 days after birth
• Infant: first 12 months of age.
• Gestational age:time from conception to
birth
• Post-natal age:time from birth to present time
• Post-conceptual age:from conception to present
age (G.A+post natal age)

5. CNS
• Gets 1/3rd of CO
• Autoregulation present, but not effective
• Myelination incomplete, senses are active
• Can feel pain , can smell & hear
• Blood – brain barrier
– Immature,hydrophilic & lipophilic cross the barrier
– Autonomic regulation good
– Parasympathetic domination
– Less number of receptors & variant protein binding

6. CNS…..
• InterVentricular hemorrhage:
– Surgical stimulation,
– inadequate analgesia,
– Airway instrumentation,
– Excessive transfusion,
prematures are more prone,
stressed neonate lacks autoregulation,
Fluctuations in CPP

7. CVS
• Heart contractile mass 30%,
• Ventricles less compliant,
• CO 350- 400ml/kg/mt.
• CO depends on heart rate & SV
• O2 consumption is 7 ml/kg/mt.
• Bradycardia is due to hypoxia, low CO,
vagal stimulation in anesthesia

8. AUTONOMIC NERVOUS SYSTEM
• Baroreceptors are immature & sensitive to
anesthetics
• Sympathectomy due to spinal or epidural-
no fall in B.P.(as sympathetic system is
immature).
• Fall of BP & HR due to sympathetic
blockade is offset by inhibition or
withdrawal of cardiac vagal activity.

9. RESPIRATORY SYSTEM
• Neonate has a large head, small weak
neck,obligate nose breather, large tongue,
U-shaped epiglottis,
funnel shaped larynx,
Subglottic portion is the narrowest
larynx is anterior & cephalad
cricoid is complete ring,
tracheal length is 2-5 cms.

10. • Respiratory centre is immature & sensitive to
depressant drugs
• More in prematures, apnoeic episodes are
common
• Lung volumes
– Tidal volume is small, 6 ml/kg 15 ml/kg
– O2 consumption is 7-9 ml/kg
– Resp.rate & alveolar vent. 2-3 times adult.
– FRC/VA ratio in neonates is 0.23,
– Changes in FiO2 causes rapid changes in oxygenation,
– MV/FRC is 5:1
– Less number of underdeveloped alveoli, surfactant less
– Ventilation is better controlled in infants < 3/12 of age

11. BLOOD
• Hb 18-19 gm/dl.
• PCV 60%
• Fetal Hb 70-90%
• ODC shifted to left
• Blood volume 80 ml/kg
• Cardiac index ,i.e CO/BSA is more

12. KIDNEYS
1. Decreased renal blood flow& decreased GFR
Days 6-24 mths
Urine vol. 1.5 2.4
ml/kg/hr
Osmolality 40-900 50-1400
EC vol.(%B.W) 42 34
Body fluid vol./ 82-107 70-75
ml/kg
Higher BSA & immature skin-evaporative losses

13. Metabolism & Thermal
Homeostasis
• O2 consumption is 7 ml/kg/mt – 7th day
• Temperature control is the most imp.
Consideration in pediatric anesthesia
• Metabolism drives MV & CO by increasing rate.
• Resting energy requirements is double that of
older child.
• Glucose is primay substrate for heart & brain

14. Metabolism & Thermal Homeostasis……
• Neonate has core temp. of 370C
– Increasing metabolic demands,
– Decreased stored carbohydrates,
– Decreased liver function,
– Increasing tendency to hypoglycemia
– Heat production by non shivering mech.

15. Metabolism & Thermal Homeostasis…..
• Neutral thermal state: minimal O2 consumption
when the difference of core & skin temp.is <
2-40C.
• Hypothermia leads to-
– catecholamines- O2 consumption
– pulmonary & peripheral vasoconstriction
– metabolic acidosis, resp.depression
– depressed conscious state, delayed recovery
– prolonged action of drugs,reduced surfactant
– dysarrythmias & cardiac depression

16. Fluid & Electrolyte Balance
• Initial fluid replacement must be low
• Overhydration can cause pulmonary edema
• Neonate requires Na: 2-3 meq/kg/day
• K : 2-3meq/kg/day
• Hypocalcemia is common in premature, sick &
acidotic
• Daily maintenance of Ca 500mg/kg/day
• Hypoglycemia is common in prematures
< 20mgs/dl

17. PAC & OPTIMISATION
• Keep in mind
– Neonatal problems
– Surgical problems
– Associated congenital problems
• Maintain
– Clear airway
– O2 therapy to achieve PaO2 of 50-70mm.Hg
– Stomach decompression
– Keep the baby warm at 370 C.
– I.V.line
– Correct acidosis if pH is < 7.3 with soda bicarb.
1-2meq/kg, slow infusion over 10-30 mts.

18. PAC & OPTIMISATION…..
– Ventilate if PaCO2 is > 50mm.Hg.
– Correct dehydration ( crystalloids),
• Insensible loss
• GI losses
• Others
– Correct hypovolemia ( colloids)
• Albumin, plasma, RBC, & whole blood if
necessary.
– Arterial line in critically ill patients.

19. MONITORING
• Precordial stethoscope or esophageal steth.
• ECG lead II
• BP cuff, oscillometer, arterial cath
• CVP – int.jugular, cubital vein
• Temp., thermister probe –
rectal,esophageal
or nasopharyngeal

20. MONITORING…..
• Ventilation
– Airway pr.monitoring,
– O2 analyser
– Mass spectrography
– Infra red capnograph
• Blood gases-
– SPO2, ETCO2, blood glucose & electrolytes

21. MONITORING…..
• Blood loss
– Small vol.suction traps,
– Swab weighing,
– Serial Hct estimation
• Urine volume
– Urinary catheter & collecting bag
• Above all, trained anesthesiologists eyes , hands &
ears are indispensible.

22. ANESTHESIA
• Major decision is whether or not the neonate needs
post-op ventilation & resuscitation.
• If post-op ventilation is needed, anesthesia
technique is of little importance, any tech. which
maintains BP & oxygenation is acceptable.
• If extubation is planned, anesthesia tech. is very
crucial.
• GA + Regional tech. with epidural Bupivacaine
0.25 %, 1 ml./kg with adrenaline is good.

23. ANESTHESIA….
• Regional block reduces doses of muscle relaxants,
narcotics & recovery will be good.
• Post-op pain relief can be planned
• All new borns must be intubated unless it is a
very minor procedure
• Consider them always ‘full stomach’
• Rapid sequence induction- no need of priming
with NDMR before DM. No fasciculations, no rise
of pressure with DMR.

24. INDUCTION
• It is to eliminate stress,
• CVS stability,
• To secure airway & ventilation,
• To prevent aspiration.
• Gastric pH at birth is 6.0; after 6 hrs. it is
2.5

25. INTUBATION
• It can be awake, or anesthetised.
• Indications for awake intubation:
– Very sick patients
– Anesthesiologist inexperienced in pediatric
anesthesia
– H/o apnoea or respiratory distress,
– Full stomach.

26. INTUBATION…..
• Complications of awake intubation:
– Arterial hypertension,
– IVH
– Apnoea,
– Obstruction to breathing,
– Desaturation & bradycardia
• Deep inhalational induction & 2% xylocaine spray
followed by intubation
• Intubation after paralysing with SUXA 2mg/kg
(controversial) , or NMDR & cricoid pressure.

27. INTUBATION…..
• Preoxygenation for 2 mts.is a must,
uncuffed ET , 20-40 cm/H2O pressure, no
pillow under the head & head extended.
• MAINTENANCE:
• Good oxygenation, prevention of stress due to pain
by short acting narcotics, intermittent inhalational &
muscle relaxants.

28. Maintenance…
– Intra – op fluid therapy:
• 0.2 % saline with 5% dextrose closely resembles the
obligatory fluid of neonate
• 4 ml/kg/hr. ( hyponatremia if given more)
• Better to use 0.45 % saline c 5% Dx.
• RL for 3rd space losses
• More 5% Dx causes hyperglycemia which leads to IVH due to
diuresis, cell dehydration & severe hyperosmolality.
• 5% Dx should not exceed 15-20ml/kg
• Serial estimation of glucose is necessary.

29. Maintenance…
• 3rd space losses in NEC, Omphalocele &
gastroschisis can exceed patients blood volume.
• CDH , congenital heart patients may not tolerate
larger vol.
• Interstitial edema develops
• Serial estimation of Hct , proteins , osmolality ,
electrolytes & urine output help in accurate
replacement of fluids.
• Neonate can tolerate 10% of blood loss
• Transfusion reactions like coagulation defects,
temp. changes, metabolic problems occur early in
neonates

30. RECOVERY
• Recovery is quick ,
• Extubation without good recovery causes
laryngeal spasm,
• Rx with IPPV , head extension , mandible thrust.
• If desaturation occurs ( < 85% ) IV suxa &
intubation.
• Don’t wait for cyanosis & bradycardia!
• Strong inspiratory efforts c obstruction causes pul.
edema,
• NMJ block must be reversed fully until active
movements of all 4 limbs occur
• Temp. must be > 35 0 C before reversal.

31. POST-OP PERIOD
• Most vulnerable period ,
hypoxia ,
laryngospasm &
cardiac arrest are common.
• Respiratory depression: Due to
– Apnoea
• Prematurity , narcotics , anesthetics , incomplete reversal ,
hypothermia , concomitant antibiotics &
hypermagnesemia –(PIH)
apnoea is more common below 41 weeks of PCA
upto 4th mth.

32. POST-OP PERIOD…
Hypoxemia due to
– Hypothermia , sepsis & acidosis.
• Rx:
FiO2 for 1st 24 hrs., monitor SaO2
• In conditions c reduced FRC like peritonitis,
int.obstruction, massive transfusions, correction of
omphalocele & gastroschisis-
minimum of CPAP should be provided

33. POST-OP PERIOD…
• Pre-op lung problems like RDS , pulmonary
dysplasia needs active ventilation.
• NMJ transmission impairment
• Hypotension may be due to hypovolemia or
residual inhalational agents
• Metabolic complications: hypocalcemia,
hypo & hyperglycemia.

34. Keep your eyes wide open …