Severe Non-Cardiogenic Pulmonary Edema Caused by a Near-Drowning in a Dog: Successful Management with CPAP Helmet Ventilation
Background
Drowning is potentially fatal. The presence of liquid in the oropharynx or larynx usually triggers a vagally mediated laryngospasm, vasoconstriction in the lungs and immediate pulmonary hypertension. Freshwater absorbed from the alveoli through the alveolar-capillary basement cause a respiratory impairment.
Case Presentation
A 4-month-old, female, entire pitt bull terrier presented in an emergency setting with severe respiratory distress and sialorrhea after freshwater near-drowning. On clinical examination the dog was alert, but with signs of cardiocirculatory shock: tachycardia (heart rate =180 bpm), hypotension (MAP =50 mm Hg), hypothermia (36°C), tachypnea (respiratory rate =110 bpm) and a severe restrictive respiratory pattern were present. Mucous membranes were cyanotic and capillary refill time could not be evaluated. Oxygen supplementation and intravenous fluids were administered (ringer lactate 20 ml/kg bolus); TFAST revealed bilateral confluent B-lines. Venous blood gas showed a moderate respiratory acidosis (pH 7.2; PCO2 52 mm Hg).
Continuous positive airway pressure (CPAP) ventilation with a pediatric helmet was started using a PEEP of 5 cm H2O. The dog was closely monitored with a continuous EKG (sinus rhythm) non-invasive blood pressure, pulse-oximetry and vetBLUE. During CPAP, respiratory rate significantly reduced (40 bpm) and an arterial blood gas (ABG) on 40% FiO2 showed: P/F ratio 483 mm Hg, pH 7.34, PCO2 47 mm Hg; electrolytes, anion gap, lactate were within normal range. Three 2-hour cycles of CPAP were performed in the first day. CPAP was switched to nasal catheter between cycles to clinically evaluate the dog. ABG was assessed at this time the last measured P/F was 350 mm Hg on room air. On day 2, TFAST showed a reduction of B-lines (4–5/field) and dog showed appetite. CPAP was stopped and oxygen supplementation was continued with a nasal catheter.
On day 3, the dog improved, and oxygen therapy was no longer tolerated. ABG before discharge showed good oxygenation: pH 7.39; PCO2 39 mm Hg; PO2 80 mm Hg; P/F ratio 349 mm Hg; A-a 21 mm Hg. The dog was discharged uneventfully.
New/Unique Information
To the authors’ knowledge this is the first report of non-cardiogenic pulmonary edema caused by near-drowning successfully managed with non-invasive CPAP ventilation support.
E-mail: gianilaceccherini@virgilio.it