Background: The aim of this post hoc analysis of a large cohort study was to evaluate the association between night-time surgery and the occurrence of intraoperative adverse events (AEs) and postoperative pulmonary complications (PPCs). Methods: LAS VEGAS (Local Assessment of Ventilatory Management During General Anesthesia for Surgery) was a prospective international 1-week study that enrolled adult patients undergoing surgical procedures with general anaesthesia and mechanical ventilation in 146 hospitals across 29 countries. Surgeries were defined as occurring during 'daytime' when induction of anaesthesia was between 8:00 AM and 7:59 PM, and as 'night-time' when induction was between 8:00 PM and 7:59 AM. Results: Of 9861 included patients, 555 (5.6%) underwent surgery during night-time. The proportion of patients who developed intraoperative AEs was higher during night-time surgery in unmatched (43.6% vs 34.1%; P<0.001) and propensity-matched analyses (43.7% vs 36.8%; P¼0.029). PPCs also occurred more often in patients who underwent night-time surgery (14% vs 10%; P¼0.004) in an unmatched cohort analysis, although not in a propensity-matched analysis (13.8% vs 11.8%; P¼0.39). In a multivariable regression model, including patient characteristics and types of surgery and anaesthesia, night-time surgery was independently associated with a higher incidence of intraoperative AEs (odds ratio: 1.44; 95% confidence interval: 1.09e1.90; P¼0.01), but not with a higher incidence of PPCs (odds ratio: 1.32; 95% confidence interval: 0.89e1.90; P¼0.15). Conclusions: Intraoperative adverse events and postoperative pulmonary complications occurred more often in patients undergoing night-time surgery. Imbalances in patients' clinical characteristics, types of surgery, and intraoperative management at night-time partially explained the higher incidence of postoperative pulmonary complications, but not the higher incidence of adverse events. Clinical trial registration: NCT01601223.

No abstract

No abstract

Ultrasound-guided right internal jugular vein catheterization (RIJV) should be the first choice to decrease the catheterrelated complications in high-risk hemodialysis patients. For this procedure, clinicians should identify the optimum positions of the RIJV, including its lower overlap with the carotid artery (CA) and high cross-sectional area of the vein. The aim of this prospective randomized study to evaluate the effects of mild ipsilateral head rotation combined with Trendelenburg position on RIJV cross-sectional area and its relation to the CA in adult patients. Forty ASA I-II patients who were undergoing elective surgery were enrolled for this study. The subjects were asked to remain supine in the 15-20Trendelenburg position. Two-dimensional ultrasound was then used to measure the degree of overlap between the RIJV and CA, the cross-sectional area of the RIJV. These measurements were compared between head rotation to the >30 left, <30 left, neutral, and <30 right positions. When the head was in the >30 left position, overlap was seen in 38 of 40 patients (95%). As the head was rotated from >30 left to <30 right, the CA-RIJV overlap (from 95% to 57.5%), and the cross-sectional area (from 14.2 mm to 8.7 mm) significantly decreased. In conclusion, when the head was turned to <30 right, the CA-RIJV overlap significantly decreased, and the cross-sectional area also decreased. When clinicians determine the optimal head position before RIJV cannulation, it is important to consider the advantages and disadvantages of the different head positions from >30 left to <30 right.

Objective:Trendelenburg positioning is a common approach used during internal jugular vein (IJV) cannulation. No evidence indicates that Trendelenburg positioning significantly increases the cross-sectional area (CSA) of the IJV in obese patients. The primary aim of this study was to determine the effectiveness of Trendelenburg positioning on the CSA of the right internal jugular vein assessed with ultrasound measurement in obese patients.Methods:Forty American Society of Anesthesiologists II patients with body mass index ≥30 kg/m2 undergoing various elective surgeries under general endotracheal anesthesia were enrolled. Ultrasound images of the right IJV were obtained in a transverse orientation at the cricoid level. We measured the CSA of the right IJV two different conditions in a sealed envelope were applied in random order: State 0, table flat (no tilt), with the patients in the supine position, and State T, in which the operating table was tilted 20° to the Trendelenburg position.Results:The change in the CSA of the IJV from the supine to the Trendelenburg position (1.80 cm2 vs 2.08cm2) was not significantly different. The CSA was paradoxically decreased in 10 of 36 patients when the position changed from State 0 to State T.Conclusions:Trendelenburg positioning does not significantly increase the mean CSA of the right IJV in obese patients. In fact, in some patients, this position decreases the CSA. The use of the Trendelenburg position for IJV cannulation in obese patients can no longer be supported.