Positioning of double-lumen tubes based on the minimum peak inspiratory pressure difference between the right and left lungs in short patients: a prospective observational study.

BACKGROUND: Peak inspiratory pressures (PIPs) during one-lung ventilation (OLV) have served as a clinical marker that could indirectly verify the proper positioning of double-lumen tubes (DLTs). Patients of short stature are highly susceptible to initial DLT malpositioning. OBJECTIVES: We investigated the usefulness of positioning left-sided DLTs using minimum PIP differences between the right and left lungs by comparing with the previously used method of auscultation without fibreoptic bronchoscopy (FOB). We also evaluated the difference in PIPs between the two lungs during OLV after the DLT was ideally positioned with FOB examination. DESIGN: Prospective, observational study. SETTING: A university hospital. PATIENTS: One hundred and two female patients of short stature (≤160  cm). INTERVENTIONS: Verification of DLT position was conducted by three sequential steps: auscultation; minimising the difference in PIP during each OLV; and verifying the resulting position by FOB. MAIN OUTCOME MEASUREMENTS: Fibreoptic bronchoscopic view results of DLT position followed by the position adjustment using the minimum PIP difference method. RESULTS: Repositioning the DLT using the minimum PIP difference led to clinically successful positioning of the DLT in 88% of patients and a more ideal placement of the tube than auscultation alone (69.6 vs. 11.8%, P <0.001). Additionally, the ideal position of DLTs verified by FOB showed that PIP differences were zero or ±1  mmHg in 93% of patients. CONCLUSION: Positioning the DLT based on the minimum PIP difference between the right and left lungs as a supplementation to routine auscultation serves as an easy and reliable method for DLT positioning and may improve the accuracy of DLT positioning as an adjuvant to FOB in short patients. TRIAL REGISTRATION: Clinicaltrial.gov identifier: NCT01533012.