Comparative study of a biofeedback-driven strategy with a standard deep breathing coaching technique used during preoxygenation of patients before induction of general anesthesia

Purpose: Preoxygenation is considered an important patient safety practice prior to induction of general anesthesia and establishment of a secure airway by most anesthesia providers. Studies show that four deep breaths over thirty seconds (four-breath technique) or eight deep breaths over sixty seconds (eight-breath technique) are superior to three to five minutes of passive spontaneous mask ventilation. However, there are no published randomized studies that evaluate maneuvers to improve the quality of deep breathing during preoxygenation in a routine clinical setting. The goal of this study is to determine if the use of a biofeedback strategy effectively improves deep breathing volumes during preoxygenation as compared to a standard coaching technique. Methods: This prospective randomized study was conducted in two groups: Investigational (N=11) and Control (N=11). Both groups were initially preoxygenated with four standardized deep breaths (DBs). For Control subjects, four additional DBs were performed using the traditional coaching technique. However, for the Investigational group, the first four DBs were followed by four breaths utilizing a biofeedback approach where increasing DB targets were provided to the patients in real time. Results: There was a statistically significant increase in volume of DBs 5 to 8 (p=0.005) in the Investigational group compared to controls. When the volume of each DB was compared to participants’ predicted VC, DB 5 to 8 in Investigational subjects more closely approximated predicted VC (p=0.002). Conclusion: DB volumes are significantly greater using a breath-to-breath biofeedback technique compared to a standardized DB coaching technique.