Continuous Positive Airway Pressure Decreased Lung Collapse During General Anesthesia Induction in Pediatric Patients

Overview

Anesthesia-induced atelectasis is a well-known entity observed in approximately 68-100% of pediatric patients undergoing general anesthesia. Infants and young children are more susceptible to this lung collapse due to their small functional residual capacity. Thus, intrapulmonary shunting caused by those atelectasis are more likely to occur during general anesthesia in infants and younger children than in adults. This problem predisposes children to hypoxemic episodes that can persist in the early postoperative period. Beyond the negative impact of atelectasis on gas exchange, mechanical ventilation induces a local inflammatory response in atelectatic lungs, even in healthy patients undergoing general anesthesia. Therefore, the diagnosis, prevention and active treatment of anesthesia-induced atelectasis are mandatory, not only to avoid hypoxemic episodes and atelectasis-related post-operative pulmonary complications, but also to protect the lungs during mechanical ventilation. Nowadays, the diagnosis of anesthesia-induced atelectasis is easily and accurately accomplished by lung ultrasound (LUS). LUS is a simple and non-invasive tool useful to detect atelectasis in children, to assess lung aeration and for monitoring ventilator settings or strategies. Regarding to the prevention of atelectasis, it was demonstrated that the application of continuous positive airway pressure (CPAP) during the induction of general anesthesia decreases atelectasis formation in adult morbidly obese patients. The investigators hypothesized that the use of CPAP during general anesthesia induction in pediatric patients can prevent or decrease atelectasis formation.

Compare lung aeration between two different strategies of induction to general anesthesia: breathing throughout a facial mask without CPAP and breathing with 5 cmH20 of CPAP in pediatric patients scheduled for surgery under general anesthesia, using ultrasound imaging and a four-point-aeration score to assess the lung aeration.