The Sick Neonate

Authors: Zach Radwine, MD (EM Senior Resident Physician, University of Illinois College of Medicine at Peoria) // Edited by: Alex Koyfman, MD (@EMHighAK)

Intro/Main Questions

Rapid evaluation and management of the sick neonate is a required skill for the emergency physician. Here we present a brief but comprehensive strategy for resuscitating and stabilizing the critically ill neonate as well as some mnemonics for help remembering the differential diagnosis.

Most common causes of catastrophic illness in the neonate:

  1. Sepsis
  2. Ductal-dependent congenital heart disease (CHD)
  3. Metabolic disturbance

Recap Basics

History

  • past medical history including pregnancy
  • gestational age, method of delivery, PROM, immediate neonatal course
  • maternal illness and labs (hep B, GBS, HIV, rubella, HSV, blood type)
  • feeding, stooling, urination
  • growth, state screening labs, discharge weight

Exam

  • vitals including BP and pulse ox in all extremities (pre and post-ductal)
  • head to toe exam including fontanel auscultation for bruit, pupils, reflexes, 4 extremity pulses, genitalia for signs of CAH (ambiguous in female, hyper-pigmented in male)
  • US: FAST, heart (1 or 2 ventricles?), lungs, IVC, aorta, aortic arch

Resuscitation

ABCs: Cardiopulmonary resuscitation first: Address airway and breathing, intubate if needed. Deviations from normal vitals should be addressed:

HR 110-180 and RR 40-60

MAP = current gestational age (eg 40 mmHg for 2 week-old born at 38 weeks)

  • IV/IO, oxygen, accucheck, monitor
  • WARM: maintain thermoneutrality w/ radiant warmer
  • To prevent complications of apnea, incr O2 consumption, hypotension:
    • use servo-control on warmer and set skin temp to 36.5
    • apply probe to abdomen
    • if complications occur slow the warming process
  • Four extremity blood pressure and pulse ox (differential suggests coarct)
  • 10ml/kg bolus initially (then repeat in 10 minutes)
  • 5ml/kg bolus if CHD is strongly suspected (these patients run isovolemic)
  • Prostaglandin (PGE1): 0.05 mcg/kg bolus + 0.01-0.05 mcg/kg/min infusion
  • Obtain central access
  • Inotropes through PIV until CVC is placed
  • Labs: CBC w diff, blood and urine cultures, UA, electrolytes, BUN/creatinine, ABG, ionized calcium, magnesium, phosphorus, ammonia, lactate and pyruvate, CSF studies
  • CXR and ECG and abdominal XR if exam warrants
  • Antibiotics: [ampicillin + gentamicin] or [ampicillin + cefotaxime]
  • Correct hypoglycemia, electrolyte and acid/base disturbance

What’s New

Differential Diagnosis: THE MISFITS and NEO SECRETS

T: Trauma, tumor, thermal
H: Heart disease, hypovolemia, hypoxia
E: Endocrine (CAH, DM, thyroid)
M: Metabolic disturbances (electrolyte imbalance)
I: Inborn errors of metabolism
S: Seizures or CNS abnormalities
F: Formula dilution or over-concentration leading to hypo/hypernatremia
I: Intestinal catastrophe (intussusception, volvulus, NEC)
T: Toxins (including home remedies such as baking soda for burping)
S: Sepsis

N: iNborn errors of metabolism
E: Electrolyte abnormalities
O: Overdose
S: Seizures
E: Enteric emergencies
C: Cardiac abnormalities
R: Recipe (formula, additives)
E: Endocrine crisis
T: Trauma
S: Sepsis

Cardiac

Statistically, the neonate in shock more likely has CHD than sepsis.

Three main ways they present:

  1. Shock: obstructed flow to body (e.g. coarct)
  2. Blue: obstructed flow to lungs (e.g. tricuspid atresia)
  3. Heart failure (e.g. AV canal defect)

ECG for treatable causes

  1. HR >200 and/or inverted p waves in I and aVF: susp SVT -> adenosine or cardioversion
  2. Big Q waves in lateral leads = ALCAPA: immediate surgery consult, very careful diuretics/inotropes
  3. LVH suggests tricuspid atresia
  • Can try 5ml/kg bolus, no more unless they respond well, should run isovolemic.
  • Give PROSTAGLANDIN and assume patient will become apneic and hypotensive: Prepare for intubation prior to giving the drug.

IMPORTANT: choice of pressor will depend on the following:

  1. Ductal dependent pulmonary lesion: cyanosis/hypoxia with normal (or under-perfused) CXR
    • Use phenylephrine for arterial squeeze (epi or levo will work too)
  2. Ductal dependent systemic lesion: shock, pre/post-ductal BP/Spo2 differential, congestion on CXR
    • Use milrinone to decrease afterload and provide inotropic support (epi, levo, or neo will increase SVR, worsen shock, and can KILL the child)
  • Can repeat 4 extremity BP/pulse ox: if differential is narrowed then duct is re-opened.
  • Replace calcium and glucose.
  • Lasix 1mg/kg IV for volume overload.

If these steps are followed it shouldn’t matter which specific lesion the child has! (except for TAPVR in which case PGE1 won’t work, but this is rare)

Infectious

  • hypothermia and irritability are concerning even without fever
  • common: GBS, listeria, E coli, Staph aureus
  • abx within first hour: amp and gent or amp and cefotaxime
  • use gent if there is strong susp for gram negative
  • early rx with acyclovir 20mg/kg IV significantly reduces mortality in HSV and should be considered especially in pts with seizures
  • skin infection: abx coverage should be expanded to cover staph
  • omphalitis is a surgical emergency: any erythema surrounding the umbilicus and extending to abdominal wall is suspicious regardless of fever
  • if sepsis is strongly suspected over CHD:
    • 20ml/kg boluses up to 60ml/kg until perfusion improves or rales develop
    • shock not reversed? -> begin inotrope through PIV/IO (delay = 20 fold mortality risk!)1
    • reverse cold shock w/ dopamine or epinephrine
    • reverse warm shock w/ norepinephrine
    • shock not reversed? -> begin hydrocortisone

Intestinal Catastrophe

IV abx, NPO, surgical consult, +/- NG tube

Malrotation w/ midgut volvulus

  • peaks in first month of life
  • “double bubble sign” on XR, definitive study is upper GI series

Intussusception

  • hx of colicky episodes
  • US or barium/air enema
  • No enema if there are signs of perforation, peritonitis, or shock

Bowel obstruction: 4 cardinal signs are…

  • maternal polyhydramnios
  • bilious emesis
  • failure to pass meconium
  • abdominal distension

Hypertrophic pyloric stenosis (HPS)

  • 3-5 weeks
  • non-bilious emesis
  • US first line or upper GI series

NEC

  • hx of stress at birth
  • usually preemie, occasionally term infant in first 10 days
  • XR shows pneumatosis intestinalis or portal free air

Meckel

  • give blood if needed (10ml/kg)
  • technetium scan

Toxic megacolon: failure to pass meconium in first 24 hours

Hyperbilirubinemia: order direct, retic, coombs

  • unconjugated is usually physiologic (breastfed, ABO incompatibility, gilbert, G6PD, spherocytosis, sepsis, criggler-najjar)
  • conjugated is always abnormal (biliary atresia or obstruction, hepatitis, alpha-1 antitrypsin)

Neurologic

Seizure: 60% hypoxic/ischemic, 5-10% intracranial infection

  • correct hypoglycemia (<40): 10% dextrose 2-4 ml/kg IV
  • lorazepam 0.1 mg/kg IV
  • phenobarb 20 mg/kg IV
  • fosphenytoin 20 mg/kg IV
  • CT or US head
  • Septic workup, give acyclovir
  • Antibiotics should not be delayed for LP

NAT: 1/3 of head trauma is missed with 30% overall mortality!

  • maintain suspicion
  • head CT, look for retinal hemorrhages

Inborn Errors of Metabolism

  • usually present day 2-7
  • initial rx should be done even in the absence of diagnosis:
    • NPO, IVF, correct acid/base and electrolyte abnormalities
  • metabolic acidosis, persistent hypoglycemia, and family history are red flags
  • lab: serum amino acids, pyruvate, lactate, urine organic acids, UA
  • serum ammonia >200 umol/L needs emergent dialysis

Electrolyte Abnormalities

  • commonly result of underlying process rather than initiating factor
  • avoid correcting too rapidly
  • hyponatremic seizure: 4-6ml/kg 3% NaCl rapid IVP
  • hyperkalemia w ECG changes: Ca gluconate 10% 100mg/kg IV over 5 min, NaHCO3 1-2mEq/kg IV over 10min, insulin 0.1 U/kg/hr infusion

Endocrine

  • hypoglycemia: 2-4 ml/kg D10 + 5-8 mg/kg/min infusion if needed
  • hypocalcemia: clonic seizures, jerking, laryngospasm, stridor, long QT
    • 100-200 mg/kg 10% Ca gluconate then repeat q6h or start infusion
  • CAH: shock unresponsive to fluids/inotropes, hypoNa, hyperK, hypoglycemia
    • aggressive fluid resuscitation, gluco and mineralocorticoids, peds endo consult
    • hydrocortisone 1-2mg/kg
  • thyrotoxicosis: hx of maternal Grave disease, failure to thrive despite hyperphagia
    • propranolol 0.25mg/kg
    • PTU 1.25 mg/kg
    • Lugol’s soln (1-5 drops PO)

Toxicologic

  • consider dermal exposures such as rubbing alcohol or Benadryl
  • homeopathic remedies (eg bicarb and etoh aka “gripe water”)
  • breast milk exposure

Bottom Line/Pearls & Pitfalls

  • Tachycardia is the first sign of shock in children.
  • Neonate in extremis without fever has CHD until proven otherwise.
  • A pink baby in shock needs PGE1 and milrinone. Epi or levo can kill them.
  • Cyanotic baby: use epi or levo to incr SVR and shunt blood toward the lungs.
  • Cyanotic baby: target SpO2 70-85%.
  • Involve specialists early.
  • Consider intubation prior to transfer, especially if the child is receiving PGE1.

Sources/Further Reading:

  1. Kissoon N, Orr RA, Carcillo JA. Updated American college of critical care medicine- pediatric advanced life support guidelines for management of pediatric and neonatal septic shock: relevance to the emergency care clinician. Pediatr Emerg Care. 2010 Nov;26(11):867-9.
  2. Shah S, Sharieff GQ. An update on the approach to apparent life-threatening events. Curr Opin Pediatr. 2007;19:288-294.
  3. Doniger S, Sharieff GQ. Pediatric Resuscitation Update. Emerg Med Clin N Am. Nov 2007;25:947-960.
  4. Brousseau T, Sharieff GQ. Newborn emergencies: the first 30 days of life.  Ped Clin N Am. Feb 2006; 53:69-84.
  5. McCollough M, Sharieff GQ. Abdominal surgical emergencies in infants and young children. Emerg Med Clin N Am. 2003 Nov;21(4):909-35.
  6. De Oliveira CF. Early goal-directed therapy in treatment of pediatric septic shock.  Shock. 2010 Sept;34(7):44-47.
  7. Brierley J, et al. Clinical practice parameters for hemodynamic support of pediatric and neonatal septic shock:2007 update from the American College of Critical Care Medicine. Crit Care Med. Feb 2009;37(2):666-88.
  8. Brooks PA, Penny DJ. Management of the sick neonate with suspected heart disease. Early Hum Dev. 2008 Mar;84(3):155-9.
  9. Steinhorn R. Evaluation and management of the cyanotic neonate. Clin Ped Emerg Med. 2008 Sept;9(3):169-175.
  10. Kim UO, Brousseau D, Konduri G. Evaluation and management of the critically ill neonate in the emergency department.  Clin Ped Emerg Med. 2008 Sept;9(3):140-148.
Edited by Alex Koyfman, MD

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