Show Notes

The Critically Ill Infant: THE MISFITS

Trauma

• ‘T’ in the mnemonic stands for trauma, which includes both accidental and intentional causes.
• Considerations for Non-accidental Trauma:
  • Stresses the importance of considering non-accidental trauma, especially given that it may not always present with obvious external signs.
• Anatomical Vulnerabilities:
  • Highlights specific anatomical considerations for infants who suffer from trauma:
    • Infants have proportionally larger heads, increasing their susceptibility to high cervical spine (c-spine) injuries.
    • Their liver and spleen are less protected, making abdominal injuries potentially more severe.

Heart

• 5 T’s of Cyanotic Congenital Heart Disease: Introduces a mnemonic to help remember key right-sided ductal-dependent lesions:
  • Truncus Arteriosus: Single vessel serving as both pulmonary and systemic outflow tract.
  • Transposition of the Great Arteries: The pulmonary artery and aorta are switched, leading to improper circulation.
  • Tricuspid Atresia: Absence of the tricuspid valve, leading to inadequate development of the right ventricle and pulmonary circulation issues.
  • Tetralogy of Fallot: Comprises four defects—ventricular septal defect, pulmonary stenosis, right ventricular hypertrophy, and an overriding aorta.
  • Total Anomalous Pulmonary Venous Connection (TAPVC): Pulmonary veins do not connect to the left atrium but rather to the right heart or veins, causing oxygen-rich blood to mix with oxygen-poor blood.
• Other Significant Conditions:
  • Ebstein’s Anomaly: Malformation of the tricuspid valve affecting right-sided heart function.
  • Pulmonary Atresia/Stenosis: Incomplete formation or narrowing of the pulmonary valve obstructs blood flow to the lungs.
• Left-sided Ductal-Dependent Lesions:
  • Conditions such as aortic arch abnormalities (coarctation or interrupted arch), critical aortic stenosis, and hypoplastic left heart syndrome are highlighted. These generally present with less obvious cyanosis and more pallor.
• Diagnostic and Management Considerations:
  • Routine prenatal ultrasounds detect most cases, but conditions like coarctation of the aorta and TAPVC might not be apparent until after birth when the ductus arteriosus closes.
  • Emphasizes the importance of a thorough physical exam: checking for murmurs, assessing hepatosplenomegaly, feeling for femoral pulses, measuring pre- and post-ductal saturations, and taking blood pressures in all four limbs.
• Treatment Recommendations:
  • Early initiation of alprostadil (a prostaglandin) for patients with suspected ductal-dependent lesions to maintain ductal patency.
  • Preparedness for potential complications from alprostadil treatment, such as apnea and hypotension, which may necessitate intubation and hemodynamic support.

Endocrine

• Focuses on acute salt-wasting crisis in undiagnosed Congenital Adrenal Hyperplasia (CAH).
• Electrolyte imbalances: ↓Na, ↑K, ↓HCO3, ↓Glu.
• Treatment: hydrocortisone (25mg for babies, 50mg for kids, 100mg for adults).

Metabolic

• Electrolyte abnormalities such as hypoglycemia (values: <60 in infants, <40 in neonates).
• Broad differential.
• Rule of 50s for correction: D% x #ml/kg fluid = 50.

Inborn Errors of Metabolism

• Major classes include organic acidurias (profound anion gap metabolic acidosis) and urea cycle defects (hyperammonemia)
• Recommendation: Draw gas and ammonia level.

Sepsis

• Emphasized as a critical condition in the differential diagnosis for ill infants, though placed later in the mnemonic for easier recall.
• Presentation and Diagnosis:
  • Sepsis in infants often presents nonspecifically, making early detection challenging.
  • Immediate drawing of blood cultures upon suspicion of sepsis.
• Initial Treatment:
  • Prompt initiation of antimicrobials and fluids.
  • Use of vancomycin for gram-positive and MRSA coverage, a third-generation cephalosporin or pip-tazo for broad bacterial coverage, and acyclovir for HSV. (tailor based on age and institutional guidelines)
• Supportive Care:
  • Highlights the necessity of fluid resuscitation to stabilize the patient.

Formula

• Formula-Related Electrolyte Imbalances:
  • Incorrect mixing of infant formula can cause hypo- or hypernatremia.
• Consequences of Electrolyte Imbalances:
  • Both conditions can lead to severe outcomes including altered mental status, seizures, coma, and potentially death.
• Management Strategies:
  • Treatment varies based on the sodium levels:
    • Symptomatic hyponatremia is treated with hypertonic saline.
    • Hypernatremia requires fluid resuscitation.

Intestinal Catastrophe

• Specific Conditions:
  • Malrotation with Midgut Volvulus: Twisting of the intestines that can obstruct blood flow.
  • Necrotizing Enterocolitis (NEC): Can occur in both full-term and preterm infants, involves inflammation and bacterial infection that can destroy bowel tissue.
  • Hirschsprung-associated Enterocolitis: Complication of Hirschsprung’s disease involving blockage and infection.
  • Intussusception: Older infants might only show altered mental status instead of the typical intermittent pain and lethargy.
• Symptoms:
  • Common symptoms include bilious emesis (green vomit) or hematemesis (vomiting blood).
• Emergency Response:
  • Urges early mobilization of pediatric surgery and radiology teams upon suspicion of these conditions.

Toxins

• Includes intentional or unintentional ingestion.
• One pill killers include: calcium channel blockers (CCB), tricyclic antidepressants (TCA), opiates, sulfonylureas, Class 1 antiarrhythmics, antimalarials, camphor, oil of wintergreen.

Seizures

• The second ‘S’ in the mnemonic refers to seizures, which can be triggered by various conditions such as hypoglycemia, sepsis, inborn errors of metabolism, and trauma.
• First-Line Treatment:
  • Actively seizing patients should initially be treated with benzodiazepines.
• Second-Line Medications:
  • Includes fosphenytoin, phenobarbital, levetiracetam (Keppra), and valproic acid.
• Management of Reversible Causes:
  • Urges prompt treatment of any identifiable causes like hypoglycemia or electrolyte imbalances.
• Special Consideration:
  • Notes the possibility of pyridoxine-dependent epilepsy in neonates, recommending pyridoxine (vitamin B6) for intractable seizures unresponsive to multiple antiepileptic drugs (AEDs).