ABSTRACT
Background: Early intraoperative hypotension is associated with acute kidney and myocardial injury in patients undergoing noncardiac surgery. Precise arterial blood pressure measurement before and during the induction of general anaesthesia may avert early intraoperative hypotension. However, rapid arterial cannulation in anxious, conscious patients can be challenging. We describe the protocol for a randomised controlled trial designed to test the hypothesis that readily available, handheld ultrasound-guided arterial cannulation is the optimal method in conscious patients undergoing noncardiac surgery. Methods: Participants >45 yr undergoing noncardiac surgery expected to last >120 min and requiring an overnight hospital stay will be eligible. We will randomly allocate participants to undergo cannulation of the radial artery in the non-dominant arm before the induction of general or regional anaesthesia using either handheld ultrasound-guided dynamic needle position technique or palpation. The primary outcome is first-pass successful arterial cannulation, analysed by intention-to-treat. Secondary outcomes include adequacy/characteristics of the arterial waveform and complications within 24 h of cannulation. We will require 118 patients to demonstrate a doubling of successful first-pass arterial cannulation, from â¼30% using the palpation approach (α=0.05; 1-ß=0.1). Results: This study has been approved by the NHS Health Research Authority and Health Care Research Wales (21/WA/0403) and commenced recruitment in May 2022. Conclusions: This study will establish whether handheld ultrasound-guided arterial cannulation before the induction of anaesthesia should be the standard of care in patients at risk of developing perioperative organ injury after noncardiac surgery. Clinical trial registration: NCT05249036.
ABSTRACT
BACKGROUND: Postoperative pulmonary complications, including pneumonia, are a substantial cause of morbidity. We hypothesised that routine noninvasive respiratory support was associated with a lower incidence of pneumonia after surgery. METHODS: Systematic review and meta-analysis of RCTs comparing the routine use of continuous positive airway pressure (CPAP), noninvasive ventilation (NIV), or high-flow nasal oxygen (HFNO) against standard postoperative care in the adult population. We searched MEDLINE (PubMed), EMBASE, and CENTRAL from the start of indexing to July 27, 2021. Articles were reviewed and data extracted in duplicate, with discrepancies resolved by a senior investigator. The primary outcome was pneumonia, and the secondary outcome was postoperative pulmonary complications. We calculated risk difference (RD) with 95% confidence intervals using DerSimonian and Laird random effects models. We assessed risk of bias using the Cochrane risk of bias tool. RESULTS: From 18 513 records, we included 38 trials consisting of 9782 patients. Pneumonia occurred in 214/4403 (4.9%) patients receiving noninvasive respiratory support compared with 216/3937 (5.5%) receiving standard care (RD -0.01 [95% confidence interval: -0.02 to 0.00]; I2=8%; P=0.23). Postoperative pulmonary complications occurred in 393/1379 (28%) patients receiving noninvasive respiratory support compared with 280/902 (31%) receiving standard care (RD -0.11 [-0.23 to 0.01]; I2=79%; P=0.07). Subgroup analyses did not identify a benefit of CPAP, NIV, or HFNO in preventing pneumonia. Tests for publication bias suggest six unreported trials. CONCLUSION: The results of this evidence synthesis do not support the routine use of postoperative CPAP, NIV, or HFNO to prevent pneumonia after surgery in adults. CLINICAL TRIAL REGISTRATION: PROSPERO: CRD42019156741.
