Abstract

Mechanical Ventilation (MV) is becoming increasingly available as a lifesaving tool in veterinary medicine. Informed decision-making is particularly important because of the labor intensity and the associated cost, and the prognosis is one of the major factors for the owner to consider. The overall survival rate with MV in heterogenous populations of dogs and cats was reported to be between 15-33%. However, this is widely varied depending on the underlying diseases process. Moreover, euthanasia accounted for a large proportion of non-survivors and the reasons potentially included financial aspects. This needs to be considered for interpretation of the results. MV from hypoxemic respiratory failure and patients with worse pulmonary function tended to have an unfavorable outcome, with the mortality rate of Acute Respiratory Distress Syndrome (ARDS), for example, up to 90%. However, patients with left-sided congestive heart failure had a better short-term outcome compared to other causes, likely because rapid improvement of pulmonary function is possible with pharmacological treatment. Patients with neuromuscular diseases such as tick paralysis and snake envenomation tended to have more favorable outcome compared to pulmonary disease because hypercapnic respiratory failure is more common. Pneumonia was the leading underlying disease for MV in puppies and brachycephalic dogs and survival rate of brachycephalic dogs might be lower compared to other breeds of dogs. The prognosis associated with the underlying causes should be the focus for the decision-making process rather than the general prognosis with MV. Moreover, further studies of ventilator strategies are required in dogs and cats which may give insights into improving patient outcomes.

Keywords:Mechanical ventilation; Dogs; Cats

Abbreviations:MV: Mechanical Ventilation; LSCHF: Left-Sided Congestive Heart Failure; ARDS: Acute Respiratory Distress Syndrome; VILI: Ventilator-Induced Lung Injury