The Usefulness of the APACHE II Score in Obstetric Critical Care: A Structured Review

To assess the performance of the Acute Physiology and Chronic Health Evaluation II (APACHE II) mortality prediction model in pregnant and recently pregnant women receiving critical care in low-, middle-, and high-income countries during the study period (1985-2015), using a structured literature review.

Ovid MEDLINE, Embase, Web of Science, and Evidence-Based Medicine Reviews, searched for articles published between 1985 and 2015.

Twenty-five studies (24 publications), of which two were prospective, were included in the analyses. Ten studies were from high-income countries (HICs), and 15 were from low- and middle-income countries (LMICs). Median study duration and size were six years and 124 women, respectively.

ICU admission complicates 0.48% of deliveries, and pregnant and recently pregnant women account for 1.49% of ICU admissions. One quarter were admitted while pregnant, three quarters of these for an obstetric indication and for a median of three days. The median APACHE II score was 10.9, with a median APACHE II-predicted mortality of 16.6%. Observed mortality was 4.6%, and the median standardized mortality ratio was 0.36 (interquartile range 0.23 to 0.73). The standardized mortality ratio was < 0.9 in 24 of 25 studies. Women in HICs were more frequently admitted with a medical comorbidity but were less likely to die than were women in LMICs.

The APACHE II score consistently overestimates mortality risks for pregnant and recently pregnant women receiving critical care, whether they reside in HICs or LMICs. There is a need for a pregnancy-specific outcome prediction model for these women.