Haemodynamic effects of remifentanil during induction of general anaesthesia with propofol. A randomised trial.

BACKGROUND: Remifentanil may have a dose-dependent haemodynamic effect during the induction of general anaesthesia combined with propofol. Our objective was to investigate whether systolic arterial blood pressure (SAP) was reduced to a greater extent when the remifentanil dose was increased. METHODS: This randomised, double-blind, dose-controlled study was conducted at the Day Surgery Unit of Haugesund Hospital, Norway. Ninety-nine healthy women scheduled for gynaecological surgery were randomly allocated in a 1:1:1 ratio to receive remifentanil induction with a low, medium or high dose corresponding to maximum effect-site concentrations (Ce) of 2, 4 and 8 ng/mL. The induction dose of propofol was 1.8 mg/kg, with a Ce of 2.9 µg/mL. Anaesthesia was induced using target-controlled infusion. After 150 s of sedation, a bolus of remifentanil and propofol was administered. Baseline was defined as 55-5 s before the bolus dose, and the total observation time was 450 s. We used beat-to-beat haemodynamic monitoring with LiDCOplus. The primary outcome variable was the maximum decrease in SAP within 5 min after bolus administration of remifentanil and propofol. Absolute and relative changes from baseline to minimal values and the area under the curve (AUC) were used as effect measures. Comparisons of groups were performed using analysis of variance (ANOVA). RESULTS: Median remifentanil doses were 0.75, 1.5 and 3.0 µg/kg in the low-, medium- and high-dose groups, respectively. The absolute changes (mean ± standard deviation) in SAP in the low-, medium- and high-dose groups of remifentanil were -39 ± 9.6 versus -43 ± 9.1, and -41 ± 10 mmHg, respectively. No difference (95% confidence interval) in the absolute change in SAP was observed between the groups (ANOVA, p = .29); medium versus low dose 3.7 (-2.0, 9.4) mmHg, and high versus medium dose -2.2 (-8.0; 3.5) mmHg. The relative changes from baseline to minimum SAP values were -30% versus -32% versus -32% (p = .52). The between-group differences in the AUC were not statistically significant. Relative changes in heart rate (-20% vs. -21% vs. -21%), stroke volume (-19% vs. -16% vs. -16%), cardiac output (-32% vs. -32% vs. -32%), systemic vascular resistance (-24% vs. -27% vs. -28%), and AUC were not statistically significant. CONCLUSION: This trial demonstrated major haemodynamic changes during the induction of anaesthesia with remifentanil and propofol. However, we did not observe any statistically significant differences between low, medium or high doses of remifentanil when using continuous invasive high-accuracy beat-to-beat monitoring.

Hemodynamic effects of a low versus a high dose of propofol during induction of anesthesia. A randomized trial.

BACKGROUND: Hypotension is common after anesthesia induction with propofol and is associated with increased morbidity. It is important to examine the effects of the proposed interventions to limit preventable hypotension, as suggested by the reduction in the dose of propofol. Our objective was to investigate whether a high dose of propofol is inferior to a low dose with respect to changes in systolic arterial blood pressure (SAP). METHODS: This randomized, double-blind, dose-controlled, non-inferiority study included 68 healthy women scheduled for gynecological surgery at the Day Surgery Unit, Haugesund Hospital, Norway. The patients were randomly allocated 1:1 to a low or high dose (1.4 mg/kg total body weight (TBW) versus 2.7 mg/kg TBW of propofol corresponding to maximal effect site concentrations (Ce) of 2.0 µg/mL versus 4.0 µg/mL. The dose of remifentanil was 1.9-2.0 µg/kg TBW, with maximal Ce of 5.0 ng/mL. The patients were observed for 450 s from the start of the infusions. The first 150 s was the sedation period, after which a bolus of propofol and remifentanil was administered. Baseline was defined as 55-5 s before the bolus doses. LiDCOplus was used for invasive beat-to-beat hemodynamic monitoring of changes in SAP, heart rate (HR), cardiac output (CO), stroke volume (SV), and systemic vascular resistance (SVR). A difference of 10 mmHg in the change in SAP was considered to be clinically important. RESULTS: The SAP change difference for low versus high dose was -2.9 mmHg (95% CI -9.0-3.1). The relative changes for low versus high dose were SAP -31% versus -36%, (p < .01); HR -24% versus -20%, (p = .09); SVR -20% versus -31%, (p < .001); SV -16% versus -20%, (p = .04); and CO -35% versus -32%, (p = .33). CONCLUSION: A high dose of propofol was not inferior to a low dose, and a reduction in the dose of propofol did not result in clinically important attenuation of major hemodynamic changes during induction in healthy women. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT03861364, January 3, 2019.

Clinical Efficacy of Combined Surgical Patient Safety System and the World Health Organization's Checklists in Surgery: A Nonrandomized Clinical Trial.

Importance: Checklists have been shown to improve patient outcomes in surgery. The intraoperatively used World Health Organization surgical safety checklist (WHO SSC) is now mandatory in many countries. The only evidenced checklist to address preoperative and postoperative care is the Surgical Patient Safety System (SURPASS), which has been found to be effective in improving patient outcomes. To date, the WHO SSC and SURPASS have not been studied jointly within the perioperative pathway. Objective: To investigate the association of combined use of the preoperative and postoperative SURPASS and the WHO SSC in perioperative care with morbidity, mortality, and length of hospital stay. Design, Setting, and Participants: In a stepped-wedge cluster nonrandomized clinical trial, the preoperative and postoperative SURPASS checklists were implemented in 3 surgical departments (neurosurgery, orthopedics, and gynecology) in a Norwegian tertiary hospital, serving as their own controls. Three surgical units offered additional parallel controls. Data were collected from November 1, 2012, to March 31, 2015, including surgical procedures without any restrictions to patient age. Data were analyzed from September 25, 2018, to March 29, 2019. Interventions: Individualized preoperative and postoperative SURPASS checklists were added to the intraoperative WHO SSC. Main Outcomes and Measures: Primary outcomes were in-hospital complications, emergency reoperations, unplanned 30-day readmissions, and 30-day mortality. The secondary outcome was length of hospital stay (LOS). Results: In total, 9009 procedures (5601 women [62.2%]; mean [SD] patient age, 51.7 [22.2] years) were included, with 5117 intervention procedures (mean [SD] patient age, 51.8 [22.4] years; 2913 women [56.9%]) compared with 3892 controls (mean [SD] patient age, 51.5 [21.8] years; 2688 women [69.1%]). Parallel control units included 9678 procedures (mean [SD] patient age, 57.4 [22.2] years; 4124 women [42.6%]). In addition to the WHO SSC, adjusted analyses showed that adherence to the preoperative SURPASS checklists was associated with reduced complications (odds ratio [OR], 0.70; 95% CI, 0.50-0.98; P = .04) and reoperations (OR, 0.42; 95% CI, 0.23-0.76; P = .004). Adherence to the postoperative SURPASS checklists was associated with decreased readmissions (OR, 0.32; 95% CI, 0.16-0.64; P = .001). No changes were observed in mortality or LOS. In parallel control units, complications increased (OR, 1.09; 95% CI, 1.01-1.17; P = .04), whereas reoperations, readmissions, and mortality remained unchanged. Conclusions and Relevance: In this nonrandomized clinical trial, adding preoperative and postoperative SURPASS to the WHO SSC was associated with a reduction in the rate of complications, reoperations, and readmissions. Trial Registration: ClinicalTrials.gov Identifier: NCT01872195.