EM@3AM: The Sick Neonate

Author: Brit Long, MD (@long_brit, EM Attending Physician, San Antonio, TX) // Reviewed by: Alex Koyfman, MD (@EMHighAK, EM Attending Physician, UTSW / Parkland Memorial Hospital)

Welcome to EM@3AM, an emDocs series designed to foster your working knowledge by providing an expedited review of clinical basics. We’ll keep it short, while you keep that EM brain sharp.

A 10-day-old female presents with her parents with poor feeding and increased work of breathing. Her urine output has been poor, but her parents have not observed fevers. The baby was born at term and did not have a prolonged hospital stay.

On examination, the baby is afebrile, but her HR is 188, RR is 61, and oxygen saturation is 94% on room air. She demonstrates increased work of breathing and retractions and appears lethargic. Her serum glucose is 48.

What is your next step in evaluation and management?

Answer:  The Sick Neonate

Background: Neonates are a distinct population with physiological differences. The sick neonate in the ED is uncommon, but terrifying. Having an approach is the most important aspect. Rapid assessment and management is vital.

Causes: There are several different approaches you can use for determining the underlying etiology. THE MISFITS and NEO SECRETS are two mnemonics that can be utilized. The most common causes of severe illness include sepsis, ductal-dependent congenital heart disease, and metabolic disturbance.

History:

• Obtain history concerning pregnancy and delivery, PROM, neonatal course, gestational age, vitamin K.
• Ask about maternal illness and lab results (GBS, HIV, rubella, HSV, Hep B).
• Inquire about neonate feeding/sweating, urination, stool, activity, skin changes, and presence of fever.
• Ask about neonate growth, screening labs, weight.

Assessment:

• Use the Pediatric Assessment Triangle: appearance, work of breathing, and circulation.
  • Appearance (TICLS): Tone, interactiveness, consolability, look/gaze (track or fix on you), speech/cry (vigorously crying but consolable vs. high pitched crying or soft wimper).
  • Work of breathing: Neonates are hypermetabolic and require close assessment of respiratory status. Look for nasal flaring, abnormal airway sounds (grunting, stridor), abnormal positioning (tripoding, head bobbing).
  • Circulation: Evaluate skin color and tone. Look closely for pallor, cyanosis, or mottling (all suggest abnormal circulation).
• Obtain vital signs with blood pressure and pulse oximetry in all four extremities.
• Perform head to toe examination. Evaluate skin, fontanelles, pulses, and genitalia (evaluation for congenital adrenal hyperplasia). Use the pediatric triangle repeatedly to assess patients.
• Assess for cyanosis, murmur, liver size, and femoral pulses.
• Irritability and hypothermia are concerning for infection.

Evaluation:

• Start with cardiopulmonary resuscitation first with airway, breathing, and circulation.
• Normal VS: HR 110-180, RR 40-60, MAP = current gestational age (39 mm Hg if 1 week old born at 38 weeks).
• Assess serum glucose and obtain access.
• Obtain ECG
  • ECG with HR > 200, inverted p waves in I and aVF, consider SVT.
  • Large Q waves in lateral leads or ST changes, consider ALCAPA.
  • LVH is abnormal and suggests tricuspid atresia.
• Obtain CXR to evaluate for pulmonary infiltrates and cardiogenic causes.
• Obtain CBC, venous blood gas, electrolytes, liver function, coagulation function, ammonia, lactate, blood cultures X2, urinalysis, lumbar puncture if able.
• Obtain head CT for concerns of head trauma.
• Perform bedside US to evaluate for source of shock and cardiac abnormalities.

Management:

• Based on differential, provide fluid bolus. If concerned for cardiogenic etiology, provide 5 ml/kg bolus. For other patients, provide 10 ml/kg bolus.
• Warm the patient (warmer to 36.5 C). Neonates are poorly insulated and may rapidly become hypothermic.
• For hypoglycemia, provide 5 mL/kg of D10 IV.
• For infection, the most common microbes are Group B streptococcus, E. coli, S. aureus.
  • Provide ampicillin and gentamicin OR cefotaxime.
    • Many consider ampicillin and gentamicin to be the first line regimen, with ampicillin and cefotaxime recommended for those with direct evidence of meningitis (please see reference number 12 for more information).
    • With the current cefotaxime shortage, substituting ceftazidime or cefepime is a valid option.
  • IV fluids 20 mL/kg up to 60 mL/kg is recommended.
  • For cold shock start epinephrine. For warm shock use norepinephrine. Norepinephrine is a safe choice.
  • If unresponsive to fluid and vasopressors, administer hydrocortisone.
  • Concern for HSV (mom with history, vesicles, elevated LFTs) warrants acyclovir.
  • Omphalitis with erythema surrounding the umbilicus is a surgical emergency.
• Cardiac: Neonates with shock but afebrile more likely have cardiac cause as opposed to infection and sepsis.
  • Three primary obstructions: Shock with obstructed flow to body (aortic coarctation), Blue with obstructed flow to lungs (tricuspid atresia), and Heart failure (AV canal defect).
  • Hyperoxia test to evaluate for cardiac disease. Perform US to evaluate cardiac chambers.
  • Consult PICU and cardiac surgeon.
  • Ductal dependent pulmonary lesion with cyanosis and hypoxia but normal chest x-ray: use phenylephrine (norepinephrine or epinephrine will work as well).
  • Ductal dependent systemic lesion with shock, difference between pre/post-ductal blood pressure and pulse oximetry, congestion on chest x-ray: consider milrinone.
  • Provide prostaglandin starting at 0.05 mcg/kg/min IV. Prepare for hypotension and hypoxia. May increase to 0.1 mcg/kg/min after 10 minutes if there is no effect.
  • Caution with IV fluids recommended; it is reasonable to start with 5 mL/kg bolus and reassess.
  • Consider furosemide 1 mg/kg IV if systemically fluid overloaded.
  • Correct glucose and electrolytes, which will improve cardiac function.
• For intestinal condition, administer broad-spectrum antibiotics, make NPO, obtain surgical consult. Assess for history/presence of bilious emesis and failure to pass meconium.
  • Malrotation with volvulus peaks in first month; evaluate with upper GI series.
  • Intussusception presents with history of colicky episodes. Diagnosis with US or air/barium enema.
  • Bowel obstruction presents with bilious emesis, history of maternal polyhydramnios, failure to pass meconium, abdominal distension.
  • Pyloric stenosis presents around 3-5 weeks, non-bilious emesis, US versus upper GI series.
  • Necrotizing enterocolitis usually occurs in patients with premature birth, occurs in first 2 weeks, X-ray show pneumatosis intestinalis or portal venous air.
  • Toxic megacolon or Hirschsprung’s disease presents with failure to pass meconium and toxic appearance.
• Hyperbilirubinemia: Obtain biliary labs, reticulocyte counts, Coombs test.
  • Unconjugated is typically physiologic.
  • Conjugated is abnormal.
• Respiratory: Muscle fatigue sets in quickly in neonates, resulting in apnea.
  • Neonates are obligatory nasal breathers, so any congestion may result in respiratory distress.
  • Pneumothoraces are rare at this age. US and X-ray can be used for diagnosis. For pneumothorax causing respiratory distress and hyoxemia, needle aspirate or place pigtail catheter.
• Seizure: Most commonly due to ischemic injury, but up to 10% due to intracranial infection.
  • Correct glucose; administer lorazepam or phenobarbital, antibiotics, acyclovir for HSV.
  • Obtain CT head and LP.
• Inborn errors of metabolism: Present within first week after birth
  • In addition to above labs, obtain serum amino acids, pyruvate, urine organic acids.
  • May have elevated ammonia, elevated lactate, low blood glucose, electrolyte abnormalities.
  • Make NPO and replete glucose; provide antibiotics for sepsis.
  • Ammonia > 200 needs dialysis.
• Endocrine:
  • Consider congenital adrenal hyperplasia in patients with shock unresponsive to fluids and vasopressors, hyponatremia, hyperkalemia, hypoglycemia.
    • Administer hydrocortisone and antibiotics.
  • Consider thyrotoxicosis for failure to thrive, maternal Graves disease.
    • Administer propranolol 0.25 mg/kg, propylthiouracil 1.25 mg/kg, hydrocortisone, antibiotics, Lugol’s solution.
  • Consider congenital hypothyroidism in those with poor feeding and poor tone.
• Electrolytes:
  • Typically due to underlying process, but avoid correcting too rapidly
  • For seizures due to hyponatremia, provide 4-6 mL/kg of 3% hypertonic saline.
  • For hyperkalemia, administer Ca gluconate 10% 100 mg/kg over 5 minutes, sodium bicarbonate 1-2 mEq/kg IV, insulin 0.1 units/kg
  • For hypocalcemia, provide 100-200 mg/kg 10% Ca gluconate.
• Trauma: Occurs rarely in this age group.
  • Subgaleal hemorrhage may result in decompensation due to low circulatory volume in neonate (5 kg neonate has 400 mL of circulating volume, 80 mL/kg X 5 kg).
  • Non-accidental trauma/abuse: Head trauma may result in 30% mortality rate. Obtain head CT and X-rays. Always keep NAT on the differential.
• Toxicologic: Consider diphenhydramine or isopropyl alcohol exposure, homeopathic exposures.

Disposition:

• Consult pediatrics and admit.
• Provide antibiotics and fluid rehydration.
• Further consultation depends on suspected underlying etiology.

A two-day-old infant presents to the emergency department with fever, poor feeding, and irritability. She was born at home at 38 weeks gestation. Which of the following is the most likely pathogen associated with early neonatal sepsis?

A) Enterococcus

B) Group B Streptococcus

C) Listeria monocytogenes

D) Staphylococcus aureus

Answer: B

Neonatal sepsis can be classified as either early onset or late onset. Early onset sepsis typically develops within 72 hours of birth and is due to vertical transmission of infection from the maternal genital tract or amniotic fluid to the infant. Risk factors for development include maternal colonization of group B streptococcus (especially if untreated during labor), premature rupture of membranes, prolonged rupture of membranes, prematurity and maternal urinary tract infection. The most common pathogen associated with early onset neonatal sepsis is group B Streptococcus. Other frequently implicated pathogens include Escherichia coli, Listeria monocytogenes, and coagulase-negative Staphylococcus. Infants may present with subtle, nonspecific findings such as irritability, poor feeding, jaundice and tachypnea, or fever and signs of septic shock. Infants presenting with signs and symptoms concerning for early onset sepsis should undergo a full diagnostic evaluation, including complete blood count, blood cultures, urinalysis, urine culture, and lumbar puncture. A chest radiograph is indicated if respiratory findings are present. Appropriate empiric antibiotics (e.g. ampicillin and gentamicin or cefotaxime) should be started while awaiting culture results.

Enterococcus (A) is more commonly seen in neonatal sepsis in premature infants. It is unlikely in otherwise healthy term infants. Listeria monocytogenes (C) is a less commonly implicated pathogen and is more likely seen during outbreaks of listeriosis. Staphylococcus aureus (D) is more commonly associated with late onset neonatal sepsis (i.e. presenting after 72 hours). Late onset sepsis is the result of horizontal transmission from caregivers or the environment to the infant.

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Further Reading:

FOAMed:
St. Emlyn’s Blog

emDocs

EMPEM

PEM Playbook

PEMBlog – Cefotaxime shortages

References:

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. Doniger S, Sharieff GQ. Pediatric Resuscitation Update. Emerg Med Clin N Am. Nov 2007;25:947-960.
3. Brousseau T, Sharieff GQ. Newborn emergencies: the first 30 days of life.  Ped Clin N Am. Feb 2006; 53:69-84.
4. McCollough M, Sharieff GQ. Abdominal surgical emergencies in infants and young children. Emerg Med Clin N Am. 2003 Nov;21(4):909-35.
5. De Oliveira CF. Early goal-directed therapy in treatment of pediatric septic shock.  Shock. 2010 Sept;34(7):44-47.
6. 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.
7. Brooks PA, Penny DJ. Management of the sick neonate with suspected heart disease. Early Hum Dev. 2008 Mar;84(3):155-9.
8. Steinhorn R. Evaluation and management of the cyanotic neonate. Clin Ped Emerg Med. 2008 Sept;9(3):169-175.
9. 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.
10. https://www.accessdata.fda.gov/scripts/drugshortages/dsp_ActiveIngredientDetails.cfm?AI=Cefotaxime%20Sodium%20(Claforan)%20Injection&st=c
11. https://redbook.solutions.aap.org/chapter.aspx?sectionid=189640241&bookid=2205
12. Clark RH, Bloom BT, Spitzer AR, et al. Empiric Use of Ampicillin and Cefotaxime, Compare With Ampicillin and Gentamicin, for Neonates at Risk for Sepsis Is Associated With an Increased Risk of Neonatal Death. Pediatrics. 2006;117:67. DOI: 10.1542/peds.20050179.