Risk for and Disparities in Critical Care during Delivery Hospitalizations.

BACKGROUND Need for critical care during delivery hospitalizations may be an important maternal outcome measure but it is not well characterized. OBJECTIVE To characterize risk for and disparities in critical care diagnoses and procedures during delivery hospitalizations. METHODS This serial cross-sectional study utilized the 2000-2014 National Inpatient Sample. The primary outcome was a composite of critical care interventions and diagnoses including mechanical ventilation and intubation, central monitoring, septicemia, coma, acute cerebrovascular disease, extracorporeal membrane oxygenation, Swan Ganz catheter monitoring, cardiac rhythm conversion, and respiratory failure. Temporal trends, risk of death, and the proportion of deaths with a critical care composite diagnosis were determined. Unadjusted and adjusted log linear regression models were fit with the critical care composite as the outcome, adjusting for demographic, clinical, and hospital factors. To evaluate the role of critical care interventions in disparities, analyses were stratified by maternal race and ethnicity. RESULTS Of 45.8 million deliveries identified, 0.21% had a critical care procedure or diagnosis during the delivery hospitalization. Overall, 75.8% of maternal deaths had an associated diagnosis from the critical care composite. The critical composite increased from 17.9 to 30.3 per 10,000 deliveries from 2000 to 2014 with an average annual percent change of 3.4% (95% CI 1.3%-5.5%). Mechanical ventilation and intubation (21.5% of cases) and respiratory failure (54.8% of cases) were the most common diagnoses present in the composite. While non-Hispanic Black women were at 32.4% higher risk than non-Hispanic white women to die in the setting of a critical care diagnosis (2.2% versus 1.7%, p<0.01), they were 162% more likely to have a critical care diagnosis (risk ratio 2.62, 95% CI 2.58, 2.66). Of clinical factors, primary cesarean delivery (aRR 7.54, 95% CI 7.43, 7.65), postpartum hemorrhage (aRR 5.11, 95% CI 5.02, 5.19), and chronic kidney disease (aRR 4.06, 95% CI 3.89, 4.23) were associated with the highest adjusted risk of the critical care composite. CONCLUSIONS Three quarters of maternal deaths were associated with a critical care diagnosis or procedure. Critical care during delivery hospitalizations increased over the study period. Maternal mortality disparities may result more from risk for conditions that require critical care rather than the care received once a critical care condition has developed.