A single-arm prospective interventional study to assess the efficacy of continuous bronchial cuff pressure monitoring to detect the displacement of lung isolation devices in elective thoracic surgeries

BACKGROUND AND AIMS: During proximal or distal migration of lung isolation device (LID), the bronchial cuff would move into a wider or narrower portion of the bronchus, leading to a decrease or increase in the cuff pressure, respectively. To test this hypothesis, we conducted a study to find out the efficacy of continuous bronchial cuff pressure (BCP) monitoring for detecting the displacement of LID. METHODS: A single-arm interventional study was conducted including hundred adult patients undergoing elective thoracic surgeries using a left-sided LID. BCP was monitored in a continuous manner using a pressure transducer connected to the bronchial cuff of the LID. The position of the LID was assessed using a paediatric bronchoscope. Changes in the BCP were noted when the LID was moved intentionally in the left main bronchus (part 1) and during the surgery (part 2). Bronchoscopic confirmation was performed at the end of the surgery to note any uncaptured movement of the LID (part 3). RESULTS: During part 1 of the study, BCP consistently decreased on the proximal movement and increased on the distal movement of the LID, although the magnitude of change was not constant. During part 2 of the study, sensitivity, specificity, positive predictive value, negative predictive value and accuracy of continuous BCP monitoring to detect the dislodgement of LIDs (n = 41) during the surgery were 97.6%, 40%, 76.9%, 88.9% and 78.7%, respectively. CONCLUSION: Continuous BCP monitoring is a useful and sensitive method for monitoring the position of left-sided LIDs in limited-resource settings.