Capnography (ETCO2), Respiratory Depression, and Nursing Interventions in Moderately Sedated Adults Undergoing Transesophageal Echocardiography (TEE)

PurposeLittle attention has been paid to the safety of moderate sedation given to adult patients undergoing transesophageal echocardiography (TEE). Although capnography has been found to indicate respiratory depression earlier than pulse oximetry in other sedation scenarios, its usefulness during TEE has not been clearly documented.DesignA prospective, single-group, observational design was used.MethodsA total of 200 adult patients undergoing TEE with moderate sedation were studied. Patient demographic and procedural physiologic variables, types and doses of sedating medications administered, incidence of respiratory depression, and types and effectiveness of nursing interventions delivered when subjects experienced respiratory depression were examined.FindingRespiratory depression identified by capnography occurred in 45% of the subjects. Capnography provided earlier identification of respiratory depression than pulse oximetry. Hydromorphone was associated with respiratory depression more so than other agents; whereas nursing interventions were effective in preventing more serious cardiorespiratory compromise.ConclusionsCapnography, as a tool to provide early warning of respiratory depression or airway compromise, has the potential to further decrease the incidence of serious adverse events due to inadvertent oversedation.