We assessed potential mechanisms that may jeopardize skeletal muscle perfusion during surgery leading to adverse outcomes including muscle injury and flap hypoxia. In craniotomy patients, we observed an increase in serum lactate and creatine kinase and urine myoglobin; indicative of muscle damage. The early rise in lactate correlated with elevated BMI, suggesting that obesity caused tissue compression and muscle ischemia. In our rodent model, we investigated the effects of flap preparation and phenylephrine on muscle perfusion by assessing microvascular blood flow and tissue PO2. Phenylephrine reduced muscle blood flow by ~20%, yet increased PO2 by ~10% suggestive of decreased O2 metabolism. At baseline, muscle flap blood flow was reduced by ~50% while PO2 was severely reduced ~80% (~5 torr) suggesting that flap perfusion was attenuated and O2 metabolism was increased. Phenylephrine infusion further reduced muscle flap perfusion. These data demonstrate multiple mechanisms by which muscle perfusion is jeopardized during surgery.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/43125 |
| Date | 05 December 2013 |
| Creators | Mak, Timothy |
| Contributors | Hare, Gregory, Mazer, David |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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