Evaluation of Nasal Oxygen Administration at Various Flow Rates and Concentrations in Conscious, Standing Adult Horses.

The research being discussed tests the impact of various oxygen concentrations and flow rates on several breathing parameters in adult horses. The results could be useful for treating horses with respiratory issues.

Research Objective

• The goal of the study was to examine the effects of different oxygen flow rates and concentrations on arterial blood gas parameters in awake, standing adult horses. The levels of inspired oxygen (also known as FO) administered to the distal trachea, the last part of the trachea before it branches into the lungs, was also measured. The research aimed to support better treatment strategies for horses with breathing problems.

Methods Used in Research

• The research involved testing on 6 healthy, alert and upright adult horses. Oxygen was supplied via a single nasal cannula that was placed in the nasopharynx, the part of the pharynx that lies behind the nose and above the soft part of the roof of the mouth.
• Three different flow rates (5L, 15L, and 30L per minute) and oxygen concentrations (21%, 50%, and 100%) were utilized, with each being delivered for 15 minutes in a random sequence.
• Both the nares (nostrils) levels and the levels in the trachea were checked to monitor the oxygen concentration (FO).

Research Findings and Results

• No adverse reactions were recorded on any of the horses during the trial with any of the flow rates.
• Arterial blood oxygen levels (PaO) and the fraction of inspired oxygen (FO) increased in line with increasing flow rates and oxygen concentrations. The increases recorded were consistent and significant.
• In all the flow rates, the fraction of inspired oxygen (FO) was significantly less at the trachea than at the nostrils when oxygen concentrations were set at 50% and 100%.
• There were no significant variations in arterial oxygen levels between providing 100% oxygen at 5L/min and 50% oxygen at 15L/min or between 100% oxygen at15L/min and 50% oxygen at 30L/min.
• At 100% oxygen-15L/min, there was a recorded increase in tracheal fraction of inspired oxygen (FO) when compared to 50% oxygen-30L/min.
• Parameters such as respiratory rate, end-tidal carbon dioxide (ETCO), the partial pressure of arterial carbon dioxide (PaCO), and blood pH did not differ significantly between the different tests.
• Administering 50% oxygen via nasal cannula at 15 and 30 L/min effectively increased arterial oxygen levels (PaO) and was well tolerated by aware, standing, healthy horses.

Implications of Research

• The results of the research could inform treatment strategies for horses experiencing lowered blood oxygen levels or hypoxemia. Administering 50% oxygen via a nasal cannula at flow rates of 15 and 30 L/min has been proven to be efficient and well-tolerated by healthy horses.
• The study recommends the evaluation of 50% oxygen administration in horses with respiratory diseases, hinting at further research in this direction.