Perioperative trends in plasma colloid osmotic pressure in horses undergoing surgery.

The research explores the differences in plasma colloid osmotic pressure (COP) among healthy horses undergoing orthopedic and gastrointestinal (colic) surgeries. The study found a significant decrease in COP during anesthesia, a noticeable increase in COP post-operation in non-GI surgery horses, and a decreased COP post-operation in GI surgery horses, especially those who did not survive or received isotonic crystalloid intravenous fluid therapy post-operation.

Research Methodology

• The study conducted from September 2009-January 2011 was a prospective clinical study executed at a Veterinary university teaching hospital involving 33 healthy, client-owned horses undergoing orthopedic (non-GI) surgery and 85 similar horses undergoing emergency exploratory celiotomy (GI).
• Data related to the horses’ parameters on presentation, surgical lesion, post-operative management, and survival were extracted from computerized clinical records.
• Heparinized blood samples were taken at different intervals including the pre-operative phase (PreOp), immediately after they recovered from anesthesia (T0), and 12 (T12) and 24 (T24) hours after recovery.
• The researchers measured COP within four hours of collection of the blood samples.

Research Findings

• Observations revealed no significant difference in PreOp or T0 COP between both groups of horses. However, a significant decrease in COP was observed during anesthesia in both groups.
• Compared to their respective pre-operative values, non-GI surgery patients exhibited a clear increase in COP at T12, unlike GI patients who saw a significant reduction.
• This COP trend persisted even at T24. More specifically, horses in the GI group that received post-operative intravenous crystalloid isotonic fluids had a significantly lower COP at T12 and T24.
• A significant observation was made regarding the horses in the GI group that didn’t survive. They had markedly lower post-operative COP values at T24.

Conclusions of the Study

• The study successfully observed and compared the perioperative trends in plasma COP in horses undergoing different types of surgeries.
• Horses undergoing exploratory celiotomy (GI group) had significantly lower COP post-operatively compared to the horses undergoing orthopedic surgery (non-GI group). The difference was even more pronounced in horses receiving post-operative isotonic crystalloid intravenous fluid therapy and those which didn’t survive the surgery.
• On the contrary, for the non-GI group of horses, an increase in COP post-operatively was common.