Mechanical ventilation beyond 24 hours is associated with improved survival outcomes in dogs: a multi-institutional analysis of 258 cases (2019-2025).

Abstract

OBJECTIVE: To evaluate survival outcomes in dogs undergoing mechanical ventilation (MV) when accounting for ventilation duration and euthanasia context, and to determine survival rates in patients ventilated &#x2265; 24 hours. METHODS: In this retrospective observational study, records were reviewed from dogs undergoing all-cause MV at 3 academic referral hospitals and 2 private specialty hospitals between March 2019 and January 2025. Data collected included underlying diagnosis, indication for MV, ventilation duration, and outcome. Indications were categorized as increased work of breathing, severe hypoxemia (Pao2 < 60 mm Hg or peripheral oxygen saturation of hemoglobin as measured by pulse oximetry < 90% despite supplemental oxygen), or hypoventilation (Paco2 &#x2265; 60 mm Hg). Ventilation duration was classified as < 24 hours or &#x2265; 24 hours, and reasons for euthanasia were recorded when available. RESULTS: Of 258 dogs, 85 (32.9%) survived to discharge, 105 (40.7%) were euthanized, and 68 (26.4%) died. Survival was 52.3% for dogs ventilated &#x2265; 24 hours compared to 13.3% for those ventilated < 24 hours. Overall, 64.7% of euthanasias occurred within 24 hours and 28.6% were financially driven. Median ventilation duration among survivors was 48 hours (range, 24 to 356 hours). CONCLUSIONS: This multi-institutional study demonstrates improved survival outcome with a 52% survival to discharge for patients ventilated &#x2265; 24 hours compared to patients ventilated < 24 hours. These findings suggest that once a patient surpasses the initial 24-hour period on MV, prognosis stabilizes at approximately 50:50, aligning more closely with human ICU survival rates. CLINICAL RELEVANCE: These findings support MV as a viable therapeutic option in veterinary critical care, and updated survival statistics provide a basis for prognostic discussions and treatment decisions.