Postoperative hypotension is common, life-threatening and poorly understood. It is associated with an increased risk of perioperative myocardial infarction, stroke, acute kidney injury and mortality. The physiological basis of postoperative hypotension after non-cardiac surgery has not been extensively investigated. As the Australian surgical population ages and acquires risk factors for postoperative hypotension, there is an urgent need to identify the common causes of postoperative hypotension so that appropriate treatments can be delivered.
This project uses point of care cardiac ultrasound and side-stream dark-field microscopy, which images the capillary circulation under the oral mucosa to identify the major physiological disturbance driving hypotension. Both techniques have been extensively used in intensive care, but few studies have used them after major non-cardiac surgery.
This project aims to illuminate the common physiological basis for postoperative hypotension and define the relative contribution of vasodilation compared to other causes of hypotension in patients having major vascular surgery. The investigators hypothesise that a majority of patients who are hypotensive postoperatively will have evidence of vasodilation. Fully understanding the causative mechanisms behind the syndrome of postoperative hypotension will allow perioperative clinicians to design appropriate treatment plans to reduce morbidity and mortality after major surgery.
This project forms part of Dr Douglas' PhD program at the University of Melbourne with the research to be undertaken at the Royal Melbourne Hospital.
Dr Ned Douglas
Associate Professor Jai Darvall
Professor Kate Leslie
The Royal Melbourne Hospital, Victoria and Department of Critical Care, University of Melbourne.
The project was awarded $A83,685 funding through the ANZCA research grants program for 2023.