LAUSR

BACKGROUND Infraclavicular subclavian vein (SCV) catheterization is a standard procedure in anesthesia and intensive care. There is a lack of evidence on how mechanical ventilation during venipuncture of the SCV influences pneumothorax rates. OBJECTIVE Primary hypothesis: non-inferiority of continuing vs. discontinuing mechanical ventilation during infraclavicular puncture of the SCV with respect to the pneumothorax rate. MATERIAL AND METHODS This prospective, randomized and single-blinded study was approved by the local ethics committee. A total of 1021 eligible patients who underwent cranial neurosurgery in 2 different university hospitals were assessed between August 2014 and October 2017. Patients were randomly assigned to two groups directly before induction of anesthesia. Intervention groups for venipuncture of the SCV were mechanical ventilation: tidal volume 7 ml/kg ideal body weight, positive end expiratory pressure (PEEP) ideal body weight/10, n = 535, or apnea: manual/spontaneous, APL valve 0 mbar, n = 486. Patients and the physicians who assessed pneumothorax rates were blinded to the intervention group. Venipuncture was carried out by both inexperienced and experienced physicians. RESULTS The pneumothorax rate was significantly higher in the mechanical ventilation group (2.2% vs. 0.4%; p = 0.012) with an odds ratio (OR) of 5.63 (95% confidence interval, CI: 1.17-27.2; p = 0.031). A lower body mass index (BMI) was associated with a higher pneumothorax rate, OR 0.89 (95% CI: 0.70-0.96; p = 0.013). CONCLUSION In this study landmark-guided infraclavicular SCV catheterization was associated with a significantly higher rate of pneumothorax when venipuncture was performed during mechanical ventilation and not in apnea. If a short phase of apnea is justifiable in the patient, mechanical ventilation should be discontinued during the venipuncture procedure.