Adverse events during the intrahospital transfer of critically ill perioperative patients in a South African tertiary hospital

Abstract

Background: Critically ill patients frequently require intrahospital transfer for diagnostic or therapeutic procedures, or transfer to the intensive care unit. Intrahospital transfer exposes patients to an increased risk of adverse events. The reported rate of adverse events ranges from 4.2% to 79% based on data from high income countries. There is limited data available on intrahospital transfers in the South African context. This study aimed to determine the incidence of adverse events during intrahospital transfer, the physiological effects of intrahospital transfer, identify potential risk factors for adverse events and determine if adverse events were associated with poor clinical outcomes. Methods: The study was a single-centre, prospective, observational study of adult patients undergoing transport between the operating theatre and the intensive care unit (or vice versa) of a tertiary academic hospital in South Africa. Demographic data, transfer data (including adverse events, and the physiological parameters of the patients before and after transfer), and intensive care unit outcome data was collected between September 2018 and May 2019.
Results: Data on 94 transfers was collected. Adverse events occurred in 23.4% (95% CI 14.7–32.1%) of transfers. Clinical adverse events, namely hypotension requiring management, made up 55% of the adverse events, while the remaining were technical adverse events (32% monitor failure, 9% ventilator failure and 4% infusion pump failure). The median transfer time was 10 minutes. Patients who developed adverse events during transfer were significantly older (median age 48 years versus 37 years, p = 0.037) and were significantly more likely to be receiving inotropic support (81.8% versus 51.4%, OR 4.26; 95% CI 1.31–13.82, p = 0.011) than those who did not have adverse events. Only the association with inotropic support remained on multivariable analysis. Patients who suffered an adverse event during transfer had a significantly higher mortality than those who did not have an adverse event (63.6% versus 30.6%, OR 3.98; 95% CI 1.46–10.84, p = 0.005) on univariate analysis, however this association was no longer significant on multivariable analysis. Increasing age, inotropic support and transfer by a medical officer as opposed to a registrar remained significant predictors on multivariable analysis. Significant physiological changes were noted in 80.9% of patients, with 64.9% of patients showing deterioration in at least one physiological parameter.
Conclusion: Adverse events are common during the transfer of critically ill patients between the operating theatre and the intensive care unit. Even in the absence of adverse events, physiological changes occur in the majority of patients undergoing transfer. Patients receiving inotropic support are at increased risk of adverse events during transfer and enhanced attention to pre-transfer preparation and intratransfer management is warranted in these patients. The potential associations between adverse events during transfer and transferring personnel and ICU mortality needs to be explored in further studies.