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- Talk
- 23/09/2021
- UK
Real Time Measurement of Intramuscular pH During Routine Knee Arthroscopy and Arthroplasty Using a Tourniquet: A Preliminary Study
Description
In this presentation, David Macdonald discusses a research project conducted in Aberdeen focusing on the real-time measurement of intramuscular pH during knee surgeries, specifically arthroscopy and arthroplasty, using a tourniquet. He begins by highlighting the advantages of tourniquets such as improved visibility and reduced bleeding but also emphasizes their risks, including reduced muscle function and potential post-tourniquet syndrome with prolonged ischemia effects.
Macdonald outlines the biochemistry behind how reduced oxygen availability affects muscle cells, leading to lactic acid production and decreased pH levels. He notes previous studies on canine subjects that indicated decreased pH levels in response to tourniquet application, and explains the goal of their study: to measure these pH changes in humans.
The methodology involves using a specific pH probe inserted into patients' leg compartments during surgery, measuring pH before and after tourniquet inflation and deflation. Over five months, they successfully recruited 39 patients, recording pH levels at regular intervals throughout the procedure, noting significant pH declines due to ischemia.
The results show clear trends in pH changes, particularly a steeper decline in the first ten minutes after tourniquet inflation, with overall lower pH observed in the arthroplasty group compared to the arthroscopy group. Macdonald concludes that their approach to measuring pH in real time is effective and presents no significant complications from the procedure, suggesting potential future applications of this research in monitoring ischemic conditions during longer surgeries.