By Eric Ramos
Intraoperative maximal change in systolic blood pressure (SBPMax) is independently associated with postoperative atrial fibrillation (AF) in patients undergoing minimally invasive oesophagectomy, according to a study presented at the 2020 Virtual Meeting of the American Society of Anesthesiologists (ASA).
“A lot of studies have looked at the preop and postop variables of the development of atrial fibrillation after surgery,” said Nikhil Keny, MD, University of California Irvine, Irvine, California. “We wanted to look at the intraoperative variables, and more specifically, we wanted to look at intraoperative blood pressure swings and see if that is associated with the development of postoperative atrial fibrillation.”
The researchers retrospectively analysed data from 96 patients who underwent minimally invasive esophagectomy at the University of California Irvine Medical Center between 2010 and 2017. Intraoperatively, an oscillometric non-invasive blood pressure cuff recorded values every 3 to 5 minutes. Values included maximal pulse pressure (PPMax), maximal change in diastolic blood pressure (DBPMax), and SBPMax.
In univariate analysis, PPMax and SBPMax were associated with higher incidence of postoperative AF. However, after adjusting for age, pre-operative beta-blocker use, and history of paroxysmal AF, only SBPMax remained independently associated.
“Something that was interesting is that intraoperative fluid balance at 5 different timepoints was not associated with the development of postoperative atrial fibrillation, even though hypovolemia is thought to be a contributor to the condition,” said Dr. Keny.
The study also found that the development of postoperative AF was associated with a significant increase in intensive care unit length of stay (4.9 vs 2.7 days; P = .023).
“Although this is a preliminary study, we found that the intraoperative maximum change in systolic blood pressure was independently associated with postoperative atrial fibrillation, and this is likely due to the effect of catecholamines release on systolic blood pressure.”
Dr. Keny noted some limitations of the study, including the retrospective nature of the study, the fact that oscillometric blood pressure measurements may not be as accurate as invasive measurements, and that the findings cannot be generalised to patients with ventricular dysfunction, as most patients enrolled in this study did not have coronary artery disease and were presumed to have normal ventricular function.