Retrospective evaluation of the outcome and prognosis of undergoing positive pressure ventilation due to cardiac and noncardiac causes in dogs and cats (2019-2020): 101 cases

Objective: To compare the short- and long-term outcomes of dogs and cats with left-sided congestive heart failure (L-CHF) undergoing positive pressure ventilation (PPV) to patients undergoing PPV for other causes and to determine risk factors associated with outcomes in this population.

Design: This retrospective study included dogs and cats that underwent PPV during 2018-2020. The study group included patients diagnosed with L-CHF. The control group included patients who were ventilated for reasons other than L-CHF. The risk factors evaluated included vital signs on presentation, ventilator settings, development of azotemia during hospitalization, cardiopulmonary resuscitation (CPR), complications, and medications used.

Setting: University Teaching Hospital.

Animals: Fifty (32 dogs, 18 cats) study group animals and 51 (39 dogs, 12 cats) control group animals were included in the L-CHF and control groups, respectively.

Measurements and main results: Sixty-six percent (33/50) of L-CHF patients, compared with 35% (18/51) of the control patients, were weaned off PPV (P = 0.002). Fifty-four percent (27/50) of the L-CHF patients survived to discharge, compared with 26% (13/51) of the control group patients (P = 0.003). However, only 54% (12/22) of the discharged L-CHF patients survived for >2 months compared to 100% of the control patients. The median survival time for dogs and cats with L-CHF surviving to discharge was 240 days (range: 1-730 days). In dogs, factors negatively associated with survival included CPR in both groups and the development of azotemia in the L-CHF group. Anemia on presentation was negatively associated with survival for both cats and dogs in the control group.

Conclusions: Dogs and cats undergoing PPV due to L-CHF were more commonly weaned off the ventilator and survived to discharge compared to other causes necessitating PPV. However, these patients suffer from severe heart disease, and therefore, their long-term survival is guarded.