Transcutaneous Carbon Dioxide Measurements in Women Receiving Intrathecal Morphine for Cesarean Delivery: A Prospective Observational Study

Abstract

(Anesth Analg. 2017;124(3):872–878) Neuraxial morphine, which is commonly used after cesarean delivery, has a favorable safety profile with a reported incidence of respiratory depression of only 0.07% to 0.9%. However, there is no standard definition of respiratory depression. The most sensitive measure may be hypercapnia (threshold of 50 mm Hg), which can be measured using the noninvasive, transcutaneous Topological Oscillation Search with Kinematical Analysis (TOSCA) monitor, which estimates arterial carbon dioxide levels (TcCO2). Thus, the authors of the present study estimated the incidence of respiratory depression as defined by hypercapnia events (TcCO2 >50 mm Hg for ≥2 min) using the TOSCA monitor in women receiving 150 μg intrathecal morphine for postcesarean analgesia.