Preliminary evaluation of the utility of comparing SpO₂/FiO₂and PaO₂/FiO₂ratios in dogs

Abstract

SF and PF in dogs spontaneously breathing room air have good correlation, suggesting that SF may be a useful, noninvasive surrogate for PF when assessing oxygenation in canine patients. Further studies are warranted to confirm and validate this relationship in spontaneously breathing and mechanically ventilated dogs on varying levels of FiO2 and to assess the ability of SF to predict outcome.

Evaluation of PaO2/FiO2and SaO2/FiO2ratios in postoperative dogs recovering on room air or nasal oxygen insufflation

“…Calabro et al performed a pilot study that evaluated SpO 2 /FiO 2 and PaO 2 /FiO 2 ratios in hypoxemic dogs presented to an urban tertiary referral hospital. All measurements in their study were obtained from dogs breathing room air and the results from their heterogeneous population of dogs revealed a moderate correlation between SpO 2 /FiO 2 and PaO 2 /FiO 2 (ρ = 0.618, P < 0.01) . In contrast to the study at hand, all dogs evaluated by Calabro et al were breathing room air; therefore, the correlation between these ratios at varying levels of FiO 2 was not evaluated.…”

“…As a result, SaO 2 /FiO 2 , and SpO 2 /FiO 2 ratios are increasingly used in people as a way to monitor oxygenation at varying levels of FiO 2 . To date, only 1 pilot study exists comparing SpO 2 /FiO 2 and PaO 2 /FiO 2 ratios in dogs with hypoxemia, and this study found moderate correlation between these ratios in a heterogenous population of hypoxemic dogs …”

“…To date, only one published report exists in veterinary medicine that evaluated a marker of arterial oxygen saturation in ratio with FiO 2 , as well as its correlation with PaO 2 /FiO 2 . Calabro et al performed a pilot study that evaluated SpO 2 /FiO 2 and PaO 2 /FiO 2 ratios in hypoxemic dogs presented to an urban tertiary referral hospital.…”

Acute respiratory distress syndrome and septic shock in a cat with disseminated toxoplasmosis

“…Due to technical difficulties in arterial sampling in a hypotensive cat, an ABG could not be performed in this case and SpO 2 was used to estimate the patient's oxygenation. In dogs, SpO 2 /FiO 2 (S:F) ratios have been shown to correlate with P:F ratios . Two studies in people have investigated the usefulness of the S:F ratio as a surrogate for the P:F ratio in the diagnosis of ALI and ARDS .…”

Care of the Ventilator Patient

“…7,8 A pilot study in dogs demonstrated moderate correlation of the SpO 2 /FiO 2 ratio to the PaO 2 /FiO 2 ratio in a heterogeneous population of dogs spontaneously breathing room air. 9 Whether this relationship holds true in mechanically ventilated dogs and cats has yet to be determined. Even if an arterial catheter is placed, continuous pulse oximetry is recommended because it provides continuous feedback and may alert the clinician to a rapid change in oxygenation status.…”