Ventilatory strategies for hypoxemia during cardiac surgery: survey validation for anesthesiologists in Brazil

Perioperative hypoxemia is common in cardiac surgeries, and atelectasis is the main cause. Besides, we can mention extracorporeal circulation (ECC), dissection of internal thoracic arteries, and previous clinical status of the patient among others as its causes. The present study elaborated an anonymous questionnaire to observe ventilatory strategies for hypoxemia in cardiac surgeries adopted by five thousand anesthesiologists all over the country.

Questionnaires were sent via e-mail for five thousand anesthesiologists in Brazil.

Out of the questionnaires sent, 81 valid responses were received. Among the answers, 65 (80%) anesthesiologists use volume-controlled ventilation (VCV), while 16 (20%) prefer pressure-controlled ventilation (PCV). The tidal volume (Vt) used is lower than 10 mL.kg(-1), for 46 (61%) versus 20 (30%) who adopt a Vt greater than 10 mL.kg(-1). Forty-seven (58%) use PEEP and 15 (21%) use FiO(2) above 60%. In the case of intraoperative hypoxemia, 20.9% increase or introduce PEEP, 70.3% increase the FiO(2), 19.7% use alveolar recruitment maneuvers, 13.5% increase the tidal volume, and 20.9% check for the presence of failures in the anesthesia equipment. Responses were sent from 15 states.

The conducts described in the questionnaires are compatible with those of the international literature. Adjusting the questionnaires format and the way to approach anesthesiologists, new studies could be undertaken.