Analysis of Prognostic Relevance based on Ambulatory Vital Signs Among Pregnancy with Pulmonary Hypertension in the ICU

Purpose: The study seeks to utilise the extensively monitored data to explore the prognostic information in the continuous ambulatory vital signs of the pregnant women with pulmonary hypertension in the ICU, aiming to bring insights to physicians on evaluation and management of these specific patients. Methods: This is a retrospective study of consecutive obstetric patients with PH admitted to ICU of the First Affiliated Hospital of Air Force Military Medical University of China, from January 2011 to May 2020. 92 cases are analysed via time-dependent Cox regression to take account of the dynamic features of vital signs. Results: Seven out of 92 maternal deaths occurred, with most maternal deaths occurring within the first three days of admission to the ICU. The vital signs for the survived are more stable and normally ranged comparing to the death. Three vital signs are identified as risk factors in the maternal in-hospital mortality model: SpO 2 (OR,0.93;95%CI,0.89-0.98), Heart rate(OR, 0.95 ; 95%CI, 0.92-0.99), Mean blood pressure(OR, 1.1 ; 95%CI, 0.98-1). The model performance is justified by the ROC curve with AUC being 0.84. Further exploration showed that the total and the longest consecutive time ratios also affect the outcome. Conclusions: Pregnancy women with PH who dead in hospital experienced long-term abnormal fluctuations in blood pressure, heart rate and blood oxygen during ICU stay. Both dynamic and time ratios reported impacts relating to SpO 2 , heart rate and blood pressure. In general SpO 2 mitigate the hazard. Effects of the heart rate and mean blood pressure should be described combining the time ratios of hypotension and tachycardia.