Acute Respiratory Failure in Pregnancy

Abstract

Acute respiratory failure in pregnancy has multiple etiologies, including thromboembolism, amniotic fluid embolism, venous air embolism, aspiration of gastric contents, respiratory infections, asthma, beta-adrenergic tocolytic therapy, and pneumomediastinum and pneu mothorax. Proper management of acute respiratory fail ure in pregnancy requires an understanding of the specific diseases and the normal gestational changes that occur in maternal respiration (decreased functional re sidual capacity, increased minute ventilation, mild respi ratory alkalosis) and hemodynamics (increased cardiac output, increased blood and plasma volume, unchanged central pressures). Knowledge of the determinants of oxygen delivery to fetal tissue (uterine blood flow, pla cental transfer, fetal circulation) and how they are af fected by changes in maternal hemodynamics, position, acid-base status, and medications can help sustain nor mal fetal development, whenever possible, without compromising maternal care. Diagnostic testing such as radiography, hemodynamic monitoring, and fetal moni toring are considered in terms of attendant risk to the mother or the fetus, alterations in normal values related to gestation, and indications for usage. Similarly, the risks and benefits of supportive and specific therapies for the various etiologies of acute respiratory therapy are reviewed.