Pulse pressure variation and systolic pressure variation in horses undergoing general anesthesia.

The research is about examining the relationship between pulse pressure variation (PPV) and systolic pressure variation (SPV) in horses when they are under general anesthesia. The study found that the initially recorded values of both PPV and SPV decreased over time, and there was not a strong agreement between these two parameters.

Research Objectives and Methods

The primary objective of this research was to describe and compare pulse pressure variation (PPV) and systolic pressure variation (SPV) in horses undergoing general anesthesia. These two measures, which can fluctuate in response to respiratory cycles, have been widely applied to predict fluid responsiveness in various species. However, their interrelation has not been clearly defined in horses.

1. Pulse Pressure Variation (PPV): Represents the fluctuation in pulse pressure during a respiratory cycle.
2. Systolic Pressure Variation (SPV): Denotes the change in systolic blood pressure throughout a respiratory cycle.

The study was conducted on 26 horses that were receiving general anesthesia and mechanical ventilation. Measurements of the maximum and minimum pulse and systolic pressure values were taken at 15-minute intervals throughout the surgery.

Results

The research results showed that both the PPV and SPV values that initially were measured at 15.6% and 10.3% respectively decreased during the first half-hour of the experiment. PPV decreased to10.7 ± 7.2% (P = 0.03) and SPV went down to 7.3 ± 3.3% (P = 0.004).

An interesting finding was that the correlation coefficient between PPV and SPV was measured at 0.52 (P < 0.0001), signifying a moderate positive correlation. However, looking at the 95% limit of agreement which ranged widely from -7.1% to 14.4%, it can be inferred that the measurements' congruence within the stated limits was not strong.

Conclusions

To sum up, this study demonstrates that while both the parameters decrease over time, there is no significant agreement or close correlation between the pulse pressure variation (PPV) and systolic pressure variation (SPV) in horses under general anesthesia. This absence of a high parallel relationship might suggest different mechanisms influencing pulse pressure and systolic pressure, requiring further investigation for complete understanding. The relevance of these measurements in assessing fluid responsiveness or other physiological aspects in horses remain to be explored in future research.