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Evaluation of PaO 2 /FiO 2 and SaO 2 /FiO 2 ratios in postoperative dogs recovering on room air or nasal oxygen insufflation
Author(s) -
Carver Andy,
Bragg Ryan,
Sullivan Lauren
Publication year - 2016
Publication title -
journal of veterinary emergency and critical care
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.886
H-Index - 47
eISSN - 1476-4431
pISSN - 1479-3261
DOI - 10.1111/vec.12475
Subject(s) - medicine , anesthesia , insufflation , arterial blood , blood pressure , room air distribution , physics , thermodynamics
Objective To evaluate partial pressure of oxygen in arterial blood/fractional percentage of inspired oxygen (PaO 2 /FiO 2 ) and SaO 2 /FiO 2 ratios (where SaO 2 is percentage of oxyhemoglobin saturation in arterial blood), and the correlation between PaO 2 /FiO 2 and SaO 2 /FiO 2 , in healthy dogs recovering postoperatively on room air versus nasal oxygen insufflation. Design Retrospective study. Setting University veterinary teaching hospital. Animals Nineteen dogs. Measurements and Main Results Medical records were retrospectively evaluated for data from a previous prospective study of dogs undergoing ovariohysterectomy, subsequently randomized to receive 100 mL/kg/min of nasal oxygen insufflation (estimated 37% FiO 2 , n = 9) or room air (estimated 21% FiO 2 , n = 10) for 2 hours postoperatively. Baseline information was obtained 1 hour intraoperatively, followed by three postoperative time points (10, 60, and 120 min). Data recorded for each time point included FiO 2 , PaO 2 , SaO 2 , PaO 2 /FiO 2 , SaO 2 /FiO 2 , partial pressure of carbon dioxide in arterial blood (PaCO 2 ), rectal temperature, and arterial blood pH. The PaO 2 /FiO 2 in dogs recovering on supplemental oxygen was significantly higher compared to dogs recovering on room air (516 ± 28 vs. 359 ± 10, P < 0.0001), whereas the SaO 2 /FiO 2 ratio in dogs recovering on supplemental oxygen was significantly lower compared to dogs recovering on room air (268 ± 0.5 versus 448 ± 1.4, P < 0.0001). The PaO 2 /FiO 2 and SaO 2 /FiO 2 ratios demonstrated excellent correlation for both groups at each postoperative time point. In dogs breathing room air, PaO 2 /FiO 2 and SaO 2 /FiO 2 correlation coefficients were 0.90, 0.95, and 0.93 ( P < 0.001). In dogs receiving supplemental oxygen, PaO 2 /FiO 2 and SaO 2 /FiO 2 correlation coefficients were 0.94, 0.93, and 0.90 ( P < 0.001). Conclusions In this population of postoperative dogs breathing either room air or with nasal oxygen insufflation, PaO 2 /FiO 2 and SaO 2 /FiO 2 had excellent correlation. Further evaluation into the correlation between SaO 2 /FiO 2 or pulse oximeter oxygen saturation (SpO 2 )/FiO 2 with PaO 2 /FiO 2 in both healthy dogs, and dogs with pulmonary dysfunction is warranted.