Physiologic effects of nasopharyngeal administration of supplemental oxygen at various flow rates in healthy neonatal foals.
OBJECTIVE
To evaluate the effects of various flow rates of oxygen administered via 1 or 2 nasal cannulae on the fraction of inspired oxygen concentration (FIO2) and other arterial blood gas variables in healthy neonatal foals.


METHODS
9 healthy neonatal (3- to 4-day-old) foals.


METHODS
In each foal, a nasal cannula was introduced into each naris and passed into the nasopharynx to the level of the medial canthus of each eye; oxygen was administered at 4 flow rates through either 1 or both cannulae (8 treatments/foal). Intratracheal FIO2, intratracheal end-tidal partial pressure of carbon dioxide, and arterial blood gas variables were measured before (baseline) and during unilateral and bilateral nasopharyngeal delivery of 50, 100, 150, and 200 mL of oxygen/kg/min.


RESULTS
No adverse reactions were associated with administration of supplemental oxygen except at the highest flow rate, at which the foals became agitated. At individual flow rates, significant and dose-dependent increases in FIO2, PaO2, and oxygen saturation of hemoglobin (SaO2) were detected, compared with baseline values. Comparison of unilateral and bilateral delivery of oxygen at similar cumulative flow rates revealed no differences in evaluated variables.


CONCLUSIONS
Results indicated that administration of supplemental oxygen via nasal cannulae appeared to be a highly effective means of increasing FIO2, PaO2, and SaO2 in neonatal foals. These findings may provide guidance for implementation of oxygen treatment in hypoxemic neonatal foals.
Wong
David M
DM
Section of Equine Medicine, Department of Veterinary Clinical Sciences, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA. dwong@iastate.edu
Alcott
Cody J
CJ
Wang
Chong
C
Hay-Kraus
Bonnie L
BL
Buchanan
Benjamin R
BR
Brockus
Charles W
CW
D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D001783:Blood Flow Velocity; D001784:Blood Gas Analysis; D002245:Carbon Dioxide / Q000097:blood / Q000378:metabolism; D006736:Horses; D001239:Inhalation / Q000502:physiology; D009305:Nasopharynx; D010100:Oxygen / Q000008:administration & dosage* / Q000097:blood / Q000494:pharmacology; D012016:Reference Values; D012143:Respiratory Physiological Phenomena
D002245:Carbon Dioxide; D010100:Oxygen