Postoperative complications and myocardial injury in patients receiving air or oxygen. Prospective, randomised and pilot study.

BACKGROUND: Supplementary oxygen is administered during anaesthesia to increase oxygen delivery and prevent hypoxia. Recent studies have questioned this routine. In this pilot study, our main aim was to investigate if 21% oxygen compared to ≥50% reduces the risk of postoperative complications and myocardial injury. METHODS: In this pragmatic, multicentre, single-blind study, patients undergoing vascular surgery were randomised to receive a fraction of inspired oxygen (Fi O2 ) ≥ 0.50 and oxygen saturation determined by pulse oximetry (SpO2 ) ≥ 98% (group H) or Fi O2 of 0.21 and SpO2 > 90% (group N) oxygen perioperatively. The primary outcome was a composite outcome of major pre-defined postoperative complications assessed at 30 days. Myocardial injury was determined by serial troponin measurements. Data were analysed using generalised estimating equation, Mann-Whitney U test or chi-squared test, as appropriate. RESULTS: The 191 patients were randomised, and per-protocol principle was used for analyses. At 30-day follow-up, 43 out of 94 patients (46%) had a postoperative complication in group H and 36 out of 90 patients (40%) in group N, p = .46. New myocardial injury was seen in 27% versus 22% in Groups H and N respectively (p = .41). No differences in other outcomes were observed between the groups. Twelve patients (13%) in Group N had SpO2 < 90%, six recovered spontaneously and six required supplemental oxygen. At 1-year follow-up, one patient in group H had died. CONCLUSION: In this pilot study, postoperative complications were similar between the groups in patients randomised to Fi O2 of 0.21 or ≥0.50 and no difference was found in the incidence of new myocardial injury. Larger, prospective adequately powered studies are needed.

Intraperitoneal ropivacaine reduces time interval to initiation of chemotherapy after surgery for advanced ovarian cancer: randomised controlled double-blind pilot study.

BACKGROUND: Advanced-stage ovarian cancer has a poor prognosis; surgical resection with the intent to leave no residual tumour followed by adjuvant chemotherapy is the standard treatment. Local anaesthetics (LA) have anti-inflammatory and analgesic effects. We hypothesised that intraperitoneal LA (IPLA) would lead to improved postoperative recovery, better pain relief, and earlier start of chemotherapy. METHODS: This was a prospective, randomised, double-blind, placebo-controlled pilot study in 40 women undergoing open abdominal cytoreductive surgery. Patients were randomised to receive either intraperitoneal ropivacaine (Group IPLA) or saline (Group Placebo) perioperatively. Except for study drug, patients were treated similarly. Intraoperatively, ropivacaine 2 mg ml-1 or 0.9% saline was injected thrice intraperitoneally, and after operation via a catheter and analgesic pump into the peritoneal cavity for 72 h. Postoperative pain, time to recovery, home discharge, time to start of chemotherapy, and postoperative complications were recorded. RESULTS: No complications from LA administration were recorded. Pain intensity and rescue analgesic consumption were similar between groups. Time to initiation of chemotherapy was significantly shorter in Group IPLA (median 21 [inter-quartile range 21-29] vs 29 [inter-quartile range 21-40] days; P=0.021). Other parameters including time to home readiness, home discharge and incidence, and complexity of postoperative complications were similar between the groups. CONCLUSIONS: Intraperitoneal ropivacaine during and for 72 h after operation after cytoreductive surgery for ovarian cancer is safe and reduces the time interval to initiation of chemotherapy. Larger studies are warranted to confirm these initial findings. CLINICAL TRIAL REGISTRATION: NCT02256228.