The relative incidence of cardiogenic and septic shock in neonates

To evaluate the relative incidence of cardiogenic and septic shock in term neonates and identify findings that help differentiate the two entities.

We conducted a retrospective chart review of term neonates presenting to British Columbia Children's Hospital (BCCH) with decompensated shock of an undiagnosed etiology between January 1, 2008 and January 1, 2013. Charts were reviewed to determine the underlying diagnoses of all neonates meeting our inclusion criteria. Patients were categorized as having septic, cardiogenic, or other etiologies of shock. We then evaluated potential demographic, clinical, and biochemical parameters that could help differentiate between septic and cardiogenic shock.

Cardiogenic shock was more common than septic shock (relative risk=1.53). A history of cyanosis was suggestive of cardiogenic shock (positive likelihood ratio, LR+=3.2 and negative likelihood ratio, LR-=0.4). Presence of a murmur or gallop (LR+=5.4, LR-=0.3), or decreased femoral pulses (LR+=5.1, LR-=0.5) on physical exam were also suggestive of cardiogenic shock as was cardiomegaly on chest x-ray (LR+=4.9, LR-=0.5). Notably, temperature instability (LR+=0.7, LR-=1.8) and white blood cell count elevation or depression (LR+=0.8, LR-=1.1) were all poor predictors of septic shock.

Cardiogenic shock is a more common cause of decompensated shock than septic shock. A history of cyanosis, murmur or gallop, or decreased femoral pulses on exam and cardiomegaly on chest x-ray are useful indicators of cardiogenic shock. In evaluating the neonate with decompensated shock, early consideration for Cardiology consultation and interventions to treat the underlying condition is warranted.