Association between postoperative hypotension and acute kidney injury after noncardiac surgery: a historical cohort analysis.

PURPOSE: The extent to which postoperative hypotension contributes to renal injury remains unclear, much less what the harm thresholds might be. We therefore tested the primary hypothesis that there is an absolute hypotensive arterial pressure threshold for acute kidney injury during the initial seven days after noncardiac surgery. METHODS: We conducted a single-centre historical cohort analysis of adults who had noncardiac surgery and had creatinine recorded preoperatively and postoperatively. Our exposure was the lowest postoperative mean arterial pressure, defined as the average of the three lowest postoperative pressure measurements. Our primary analysis was the association between the lowest mean arterial pressure and acute kidney injury, defined according to Kidney Disease: Improving Global Outcomes initiative criteria. Our analysis was adjusted for potentially relevant confounding factors including intraoperative hypotension. RESULTS: Among 64,349 patients analyzed, 2,812 (4.4%) patients had postoperative acute kidney injury. Each 5-mm Hg decrease in the lowest mean arterial pressure was associated with a 28% (97.5% confidence interval [CI], 23 to 32; P < 0.001) increase in the odds of acute kidney injury for lowest mean arterial pressures < 80 mm Hg. Higher lowest pressures were not associated with acute kidney injury (odds ratio, 1.08; 97.5% CI, 0.99 to 1.17; P = 0.04) for each 5-mm Hg decrease in the lowest mean arterial pressure. CONCLUSION: Postoperative hypotension, defined as the lowest postoperative mean arterial pressure < 80 mm Hg, was associated with acute kidney injury after noncardiac surgery. A prospective trial will be required to determine whether the observed association is causal and thus amenable to modification.

RéSUMé: OBJECTIF: Nous ne savons pas dans quelle mesure l'hypotension postopératoire contribue aux lésions rénales, et nous connaissons encore moins les seuils de lésion. Nous avons donc testé l'hypothèse primaire selon laquelle il existerait un seuil absolu de tension artérielle hypotensive pour l'insuffisance rénale aiguë au cours des sept premiers jours suivant une chirurgie non cardiaque. MéTHODE: Nous avons mené une analyse de cohorte historique monocentrique auprès d'adultes ayant bénéficié d'une chirurgie non cardiaque et pour lesquel·les les taux de créatinine avant et après l'opération avaient été enregistrés. Notre exposition était la tension artérielle moyenne postopératoire la plus basse, définie comme la moyenne des trois mesures de tension postopératoire les plus basses. Notre analyse principale a porté sur l'association entre la tension artérielle moyenne la plus basse et l'insuffisance rénale aiguë, définies selon les critères de l'initiative KDIGO (Kidney Disease: Improving Global Outcomes). Notre analyse a été ajustée pour tenir compte des facteurs de confusion potentiellement pertinents, notamment de l'hypotension peropératoire. RéSULTATS: Parmi les 64 349 patient·es analysé·es, 2812 (4,4 %) ont présenté une insuffisance rénale aiguë postopératoire. Chaque diminution de 5 mm Hg de la tension artérielle moyenne la plus faible était associée à une augmentation de 28 % (intervalle de confiance [IC] de 97,5 %, 23 à 32; P < 0,001) des risques d'insuffisance rénale aiguë pour les tensions artérielles moyennes les plus faibles < 80 mm Hg. Des tensions les plus faibles plus hautes n'ont pas été associées à une insuffisance rénale aiguë (rapport de cotes, 1,08; IC 97,5 %, 0,99 à 1,17; P = 0,04) pour chaque diminution de 5 mm Hg de la tension artérielle moyenne la plus faible. CONCLUSION: L'hypotension postopératoire, définie comme la tension artérielle moyenne postopératoire < 80 mm Hg la plus basse, a été associée à une insuffisance rénale aiguë après une chirurgie non cardiaque. Une étude prospective sera nécessaire pour déterminer si l'association observée est causale et donc susceptible d'être modifiée.

Perioperative Supplemental Oxygen and Postoperative Nausea and Vomiting: Subanalysis of a Trial, Systematic Review, and Meta-analysis.

BACKGROUND: Intraoperative supplemental oxygen may reduce postoperative nausea and vomiting by mitigating hypoxic stress on the gastrointestinal tract. The authors therefore tested the hypothesis that supplemental oxygen reduces nausea and vomiting in adults recovering from colorectal surgery at the Cleveland Clinic between January 28, 2013, and March 11, 2016. METHODS: Initially, the authors conducted an unplanned subanalysis of a previous trial that evaluated the effect of 80% versus 30% intraoperative inspired oxygen on surgical site infection. Specifically, they assessed the effect of 80% versus 30% oxygen concentration on the incidence of postoperative nausea and/or vomiting. Thereafter, the authors conducted a systematic review and meta-analysis of the effect of supplemental oxygen on postoperative nausea and vomiting. RESULTS: The authors' underlying analysis included 5,057 colorectal surgeries on 4,001 patients. For 2,554 surgeries, assignment was to 80% oxygen, and in 2,503 surgeries, to 30%. Postoperative nausea and vomiting was 852 of 2,554 (33%) in 80% oxygen and 814 of 2,503 (33%) in 30% oxygen. The estimated relative risk (95% CI) of 80% versus 30% oxygen on postoperative nausea and vomiting was 1.04 (0.96 to 1.12) in a generalized estimating equation model adjusting for within-patient correlation for patients with multiple surgeries, P = 0.355. Furthermore, supplemental oxygen did not reduce antiemetic use (P = 0.911) or the severity of nausea and vomiting (P = 0.924). The authors' meta-analysis included 10 qualifying trials (6,749 patients) and did not find a difference in postoperative nausea and vomiting: relative risk, 0.97 [95% CI, 0.86 to 1.08], P = 0.55, I2 = 52%. CONCLUSIONS: The incidence of postoperative nausea and vomiting did not differ in patients assigned to 80% or 30% inspired oxygen. A meta-analysis of available trials similarly indicated that supplemental intraoperative oxygen does not reduce postoperative nausea and vomiting. Therefore, supplemental oxygen should not be given in the expectation that it will reduce nausea and vomiting.

Effect of intraoperative subhypnotic infusion of propofol on postoperative nausea and vomiting: A retrospective analysis.

STUDY OBJECTIVE: To measure the possible association between subhypnotic propofol infusion during general balanced anesthesia and the incidence of PONV. DESIGN: Retrospective Cohort Analysis Using Propensity Score Matching. SETTING: Postanesthesia care unit and inpatient unit. PATIENTS: Patients with American Society of Anesthesiologists (ASA) physical status I-IV, undergoing non-cardiac surgery lasting >2 h were included. Patients were excluded if transferred to the intensive care unit after surgery or received ketamine. Initially 70,976 patients were screened, and a cohort of 51,707 eligible adult patients undergoing non-cardiac surgery under general balanced anesthesia between 2015 and 2019 were included. Using a propensity score matching, 3185 patients who received subhypnotic propofol during general balanced anesthesia were matched with 5826 patients who did not receive subhypnotic propofol in a 1:2 ratio. INTERVENTIONS: None. MEASUREMENTS: The primary outcome was the incidence of PONV during PACU stay. The secondary outcome was the incidence of PONV within the first 24 h after surgery. Exploratory outcomes were time-to-extubation and length of hospital stay. MAIN RESULTS: A total of 9011 patients were included (3185 patients who received propofol infusion, and 5826 patients who did not receive propofol infusion) after propensity score matching. The adjusted odds ratio for PONV incidence was 1.03 (95% CI: 0.90, 1.18; p = 0.635) in PACU, and 1.05 (95% CI: 0.90, 1.23; P = 0.50) within 24 h after surgery. The length of hospital stay was 6 h shorter (ratio of means (95% CI) of 0.92, 0.89, 0.94), p < 0.001) and time-to-extubation was 2 min longer (ratio of means 1.24 (1.20, 1.28), p < 0.001) in patients receiving subhypnotic propofol infusion. CONCLUSIONS: Our study suggests that subhypnotic propofol infusion during general balanced anesthesia is not associated with a reduction in the incidence of PONV during PACU stay and within the first 24 h after surgery. However, it is associated with decreased LOS and increased time-to-extubation, but differences in neither outcome were clinically important.

Emerging drugs for the treatment of postsurgical pain.

INTRODUCTION: Postoperative pain is a distressful experience and remains to be a significant concern after surgery. Current agents either fail to prevent or minimize postoperative pain or cause a series of adverse effects, addiction, or abuse. Opioids have been the gold standard in the treatment of postoperative pain despite their well-described adverse effects. Many new agents with different mechanisms of action have been recently introduced to address this issue. AREAS COVERED: This current review summarizes the list of new and emerging drugs investigated for their efficacy in controlling the postoperative pain and decreasing the need for rescue opioid use, adverse effect profile, abuse, and addiction potential. EXPERT OPINION: Opioids have unrivaled analgesic efficacy. However adverse effects of opioids led to the search for better options. In mild pain most of the emerging drugs have been shown to control postoperative pain and decrease the use of rescue opioid, however fail to control pain after major surgeries causing severe pain. Specific agents such as Oliceridine, new local anesthetics, etc., are effective in controlling severe pain and hold a promise to replace opioids in the near future.