Effects of Different Oxygen Concentrations on Anesthetized Horses
Author Information
Author(s): Hubbell John AE, Aarnes Turi K, Bednarski Richard M, Lerche Phillip, Muir William W
Primary Institution: The Ohio State University
Hypothesis
0.5 FiO2 would reduce ventilation-perfusion mismatching and increase the fraction of pulmonary blood flow that is oxygenated, thus improving arterial oxygen content and DO2.
Conclusion
Reducing FiO2 did not change alveolar dead space ventilation or shunt fraction in dorsally recumbent, mechanically ventilated horses during 3 hr of isoflurane anesthesia.
Supporting Evidence
- Arterial partial pressures of O2 were significantly higher in the >0.95 FiO2 group.
- Oxygen delivery did not change from preanesthetic levels in either group during anesthesia.
- Shunt fraction increased in both groups during anesthesia.
- Reducing FiO2 did not improve oxygenation or oxygen delivery.
Takeaway
Using less oxygen during horse anesthesia didn't help them breathe better or get more oxygen to their bodies.
Methodology
Five horses were anesthetized and compared while breathing either 0.5 FiO2 or >0.95 FiO2 for 3 hours.
Potential Biases
Potential bias due to the small sample size and the specific conditions of the study.
Limitations
The study had a small sample size and did not account for all potential variables affecting oxygenation.
Participant Demographics
Five mature horses (one Thoroughbred, one Quarterhorse, three Standardbreds; two geldings, three mares) with a mean body weight of 614 kg.
Statistical Information
P-Value
p<0.05
Statistical Significance
p<0.05
Digital Object Identifier (DOI)
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