By Michael Vlessides
Originally published by our sister publication, Anesthesiology News
Is there a link between anesthesia handovers during cardiac surgery and increased postoperative mortality? A study has found evidence for this association.
The multicenter team of Canadian researchers concluded that such handovers were not only significantly associated with increased 30-day and one-year mortality, but also ICU length of stay.
“We know from the literature that anesthesiology handover is common and is actually becoming more common year on year,” said John O’Connor, MD, a cardiac anesthesia fellow at the University of Ottawa Heart Institute, in Ontario. “In addition, anesthesiology handover is more common in cardiac surgery than noncardiac surgery.
“Although anesthesiology handover has been associated with increased morbidity and mortality, the precise impact of anesthesiology handover after cardiac surgery is not fully understood,” he added. “To our knowledge, this has not been investigated at a population level, nor has it been investigated up to one year after surgery.”
To shed light on this possible relationship, Dr. O’Connor and his colleagues examined patients presenting for a series of cardiac surgical procedures in Ontario between October 2008 and September 2019. Patients were included in the retrospective cohort study if they underwent coronary artery bypass surgery, single or multiple valve surgery, thoracic aortic procedures, or a combination thereof. Heart transplantation and ventricular assist device implantation surgeries were excluded. The trial’s primary end point was one-year mortality, and secondary end points included 30-day mortality and ICU length of stay.
Propensity score analysis was used to control for potential confounding variables, including patient characteristics, procedure type, surgeon characteristics and anesthesiologist characteristics. Multivariable Cox proportional hazard models assessed the relative hazard of 30-day and one-year mortality, and Poisson regression estimated the effect of intraoperative handover on ICU length of stay.
The final study cohort consisted of 102,209 cases. Anesthesia handover occurred in 1,926 of the group (1.9%). Interestingly, intraoperative anesthesiology handovers were found to occur more commonly in male patients, emergent procedures, academic hospitals, with female primary anesthesiologists, and among surgeons with lower case volumes.
A Question of Handover Method
In a presentation at the 2021 virtual annual meeting of the Society of Cardiovascular Anesthesiologists, Dr. O’Connor reported that intraoperative anesthesiology handover was associated with a 52% increased risk for mortality at one year (hazard ratio [HR], 1.52; 95% CI, 1.1-2.0). Similarly, patients who experienced such handovers also had a 61% increased risk for 30-day mortality (HR, 1.61; 95% CI, 1.1-2.3).
In addition, the study found a rate ratio for increased ICU length of stay of 1.45 (95% CI, 1.2-1.3).
These results were corroborated by Kaplan-Meier analysis, which found lower estimated one-year survival for patients whose procedures were subject to anesthesiology handovers. “The difference in patient survival is evident early in the postoperative course and continues over quite a long period of time,” Dr. O’Connor said.
As Dr. O’Connor explained, the study demonstrates the risk presented by intraoperative anesthesia handover among cardiac surgery patients. “That’s even after controlling for patient factors, procedure factors and staffing factors,” he said. Nevertheless, the authors recognized the need for more research to clarify the relationship and the potential effect of external factors.
“How is handover being performed?” Dr. O’Connor asked. “What tools are being used? And is adequate training occurring for this? Finally,” he added, “we think that handover tools specific to cardiac anesthesiology possibly need to be developed and put in place to enhance patient safety. Perhaps we need to do something a little different to change these results.”
Look to the Aviation Industry
For Alparslan Turan, MD, whose group conducted similar research covering all surgical cases (Anesthesiology 2014;121[4]:695-706), the benefits of a streamlined handover process are clear. “The most structured handover processes in the world come from the aviation industry,” said Turan, a professor and the vice-chair of the Department of Outcomes Research at Cleveland Clinic, in Cleveland. “I think these types of processes need to be implemented in anesthesiology.
“There are multiple studies in every aspect of anesthesia care to show what a critical time it is in the perioperative process,” he said. “Handovers are a time when critical information can be lost, which ultimately affects outcomes for the patient—all the studies show that.”
Yet the way Turan sees it, the standardization of handovers needs to be the product of institutional or even societal efforts. “The motivation should come from higher up and be implemented in every case. The ASA has rules for things like monitoring, and the same should go for handovers, which should be a part of the quality evaluation of anesthesia programs and departments.”