A pilot study in healthy volunteers to assess the influence of time spent in the Trendelenburg position on cognitive function (BRAIN Study)

1st October 2014

Status: Ended

Specialism: Surgical.

Team: Dr Austin Acheson.

Laparoscopic surgery is preferred to open surgery in suitable colorectal cancer resections. Several trials have compared the benefits of laparoscopic surgery over open surgery for colon cancer revealing many benefits of laparoscopic surgery including less blood loss, earlier return of bowel function, need for fewer analgesics post-operatively and a shorter stay in hospital. These were achieved without an increase in morbidity or mortality. However, to carry out laparoscopic surgery patients are often placed in extreme positions to use gravity to help with retraction of organs and therefore give the surgeon the view required to carry out the operation. This may be in the form of extreme head down tilt for up to four or five hours during complex colorectal resections .

Studies have shown that head-down positioning increases central venous pressure and impairs venous outflow from the brain thus increasing the hydrostatic pressure within the brain’s vasculature. As microvascular fluid exchange is governed by hydrostatic and osmotic pressure, the increase in hydrostatic pressure increases extracellular water content which may eventually induce an increase in intracranial pressure (ICP) and cerebral oedema. In turn this may result in increased cerebrovascular resistance and reduced cerebral blood flow resulting in impaired tissue oxygenation. We know from other specialties that cognitive decline can result in an increase in confusion resulting in an increased length of hospital stay. Although studies have looked at the effect of Trendelenburg positioning on ICP and cerebral perfusion pressure, they have not looked at its effect on cognitive function.

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dr-austin-acheson Dr Austin Acheson Research Summary Interests Chronic anal fissure Anal sphincter Pharmacology Intravenous iron therapy in IDA Laparoscopic Colorectal Surgery Techniques In vitro models for sphincter pharmacology clinical studies…