Effect of pneumatic leg compression on post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy: a double-blind randomised controlled trial

The influence of anesthetic drug strategy on the incidence of post-induction hypotension in elective, non-cardiac surgery - A prospective observational cohort study

STUDY OBJECTIVES

To identify the influence of modifiable factors in anesthesia induction strategy on post-induction hypotension (PIH), specifically the type, dosage and speed of administration of induction agents. A secondary aim was to identify patient related non-modifiable factors associated with PIH.

DESIGN

Single-center, prospective observational cohort study.

SETTING

Operating room.

PATIENTS

Adult, ASA I-IV patients undergoing elective, non-cardiac surgery under general anesthesia (GA).

INTERVENTIONS

None.

MEASUREMENTS

Continuous non-invasive blood pressure using finger-cuff technology. PIH was defined as mean arterial pressure (MAP) <65 mmHg ≥1 min, and, separately, as a > 30 % decrease from baseline MAP ≥1 min.

MAIN RESULTS

Study measurements were performed in 760 patients, of which 720 were suitable for analysis. A total of 238 patients (33.1 %) experienced PIH according to the 65 mmHg threshold, and 287 (39.9 %) using the 30 % decrease in MAP threshold. Remifentanil administration was associated with increased risk of PIH according to either definition (MAP <65 mmHg: OR 1.88, 95 %CI 1.31-2.69, p < 0.001, 30 % MAP decrease: OR 1.66, 95 %CI 1.15-2.40, p = 0.007). Pre-emptive vasopressor use (before or during first minute of GA) was associated with reduced risk of PIH (MAP <65 mmHg: OR 0.65, 95 %CI 0.45-0.95, p = 0.027, MAP 30 % decrease: OR 0.58, 95 %CI 0.40-0.84, p = 0.004). Speed of propofol bolus administration, propofol bolus dose, and esketamine use were not associated with PIH in multivariable analysis. Propofol bolus dose decreased with increasing age and American Society of Anesthesiologists physical status classification.

CONCLUSIONS

PIH was common in this patient cohort, regardless of the definition used. Two of the five examined modifiable factors were associated with PIH: remifentanil infusion was associated with an increased risk, and pre-emptive vasopressor use was associated with a decreased risk of PIH. No association between propofol dose and PIH was found, most likely due dose adjustment based on clinical assessment rather than a true absence of effect.

CLINICAL REGISTRATION NUMBER

This study was registered in the Dutch Medical Research in Humans (OMON) register on 18 June 2019 (ID: NL7810). The study was approved by the Medical Ethics Committee of the Amsterdam UMC, location AMC, the Netherlands in December 2018 (NL 6748.018.18; 2018).

Effect of pneumatic leg compression on phenylephrine dose for hypotension prophylaxis via variable rate infusion at cesarean delivery: an unblinded randomized controlled trial

BACKGROUND

Phenylephrine infusion is recommended to prevent spinal hypotension during cesarean delivery (CD) but may be associated with dose-dependent side effects. We hypothesized that adding intermittent pneumatic compression (IPC) of the lower legs to a variable-rate phenylephrine infusion will reduce the dose of phenylephrine required during CD.

METHODS

Seventy-six healthy women undergoing elective CD under combined spinal-epidural anesthesia were randomly assigned to IPC or control groups (n = 38 per group). After spinal anesthesia, IPC of the lower legs was initiated in the IPC group, and all women received a phenylephrine infusion starting at 25 μg·min-1 and increasing by 16.7 μg·min-1 for systolic blood pressure (SAP) < 90% baseline. If hypotension (SAP < 80% baseline) occurred, 100 μg phenylephrine bolus was administered. The primary outcome was the dose of phenylephrine per minute.

RESULTS

The dose of phenylephrine per minute (34.4 ± 7.3 μg·min-1 vs. 40.9 ± 9.5 μg·min-1, P = 0.001; mean difference -6.6 μg·min-1, 95% CI -10.5 to -2.7 μg·min-1) and the incidence of hypotension (24% vs. 55%, P = 0.005) were lower in the IPC group than in the control group. There were no significant differences between the two groups in the total dose of phenylephrine (603.2 ± 217.1 μg vs. 706.2 ± 247.5 μg, P = 0.058; mean difference -102.9 μg, 95% CI -209.4 to 3.5 μg), maternal side effects, or neonatal outcomes.

CONCLUSIONS

Intermittent pneumatic compression combined with a variable-rate phenylephrine infusion reduced the phenylephrine dose per minute and the incidence of hypotension during CD under spinal anesthesia.

Preoperative echocardiography and anesthetic drugs as predictors of post-induction hypotension during general anesthesia: a prospective observational study

Post-induction hypotension (PIH) during general anesthesia is a serious concern due to its high incidence and association with adverse postoperative outcomes and prognosis. We prospectively enrolled consecutive 1,603 patients scheduled for non-cardiac and cardiac surgery under general anesthesia. The primary outcome was defined as the lowest mean blood pressure from induction of general anesthesia to the start of surgery: post-induction blood pressure (PIB). Multivariable regression analysis was used to investigate the relationships between PIB and preoperative echocardiographic measurements, types and doses of anesthetic agents, and preoperative comorbidities and oral medication. Left ventricle regional wall motion abnormality (RWMA) and lower estimated glomerular filtration rate significantly associated lower PIB. Factors significantly associated with higher PIB were high BMI, beta blockers, high pre-induction mean blood pressure, and starting induction in the afternoon. Sevoflurane and prophylactic norepinephrine use were associated with higher PIB as anesthetic interventions. Significant interactions were found between sevoflurane and RWMA (P for interaction: 0.01). This is the first study to demonstrate the feasibility of intervening in the selection of anesthetic agents based on echocardiographic findings and to recommend the use of sevoflurane and prophylactic norepinephrine for the prevention of PIH, especially in patients with RWMA.

Efficacy and Safety of Remimazolam Versus Etomidate for Induction of General Anesthesia: Protocol for a Systematic Review and Meta-Analysis

BACKGROUND

Postinduction hypotension (PIHO) is a hemodynamic abnormality commonly observed during the induction of general anesthesia. Etomidate is considered a safer drug for the induction of anesthesia because it has only minor adverse effects on the cardiovascular and pulmonary systems. Recent evidence indicates that the novel benzodiazepine remimazolam has minimal inhibitory effects on the circulation and respiration. However, the efficacy and safety of remimazolam versus etomidate in the induction of anesthesia are unclear.

OBJECTIVE

To further understand the potential of remimazolam in anesthesia induction, it is necessary to design a meta-analysis to compare its effects versus the classic safe anesthetic etomidate. The aim of this study is to determine which drug has more stable hemodynamics and a lower incidence of PIHO. Our study will also yield data on sedation efficiency, time to loss of consciousness, time to awakening, incidence of injection pain, and postoperative nausea and vomiting with the two drugs.

METHODS

We plan to search the Web of Science, Cochrane Library, Embase, PubMed, China National Knowledge Infrastructure, and Wanfang databases from the date of their creation until March 31, 2025. The language is limited to English and Chinese. The search terms are "randomized controlled trials," "etomidate," and "remimazolam." The incidence of PIHO is the primary outcome measure. Secondary outcomes include depth of anesthesia after induction, sedation success rate, time to loss of consciousness, hemodynamic profiles, recovery time, incidence of injection pain, and postoperative nausea and vomiting. Reviews, meta-analyses, case studies, abstracts from conferences, and commentaries will not be included. The heterogeneity of the results will be evaluated by sensitivity and subgroup analyses. RevMan software and Stata software will be used for data analysis. We will evaluate the quality of included studies using version 2 of the Cochrane risk-of-bias tool. The confidence of the evidence will be assessed through the Grading of Recommendations, Assessments, Developments, and Evaluations system.

RESULTS

The protocol was registered in the international PROSPERO (Prospective Register of Systematic Reviews) registry in November 2023. As of June 2024, we have performed a preliminary article search and retrieval for further review. The review and analyses are expected to be completed in March 2025. We expect to submit manuscripts for peer review by the end of June 2025.

CONCLUSIONS

By synthesizing the available evidence and comparing remimazolam and etomidate, we hope to provide valuable insights into the selection of anesthesia-inducing drugs to reduce the incidence of PIHO and improve patient prognosis.

TRIAL REGISTRATION

PROSPERO CRD42023463120; https://tinyurl.com/333jb8bm.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

PRR1-10.2196/55948.

Carotid blood flow changes following a simulated end-inspiratory occlusion maneuver measured by ultrasound can predict hypotension after the induction of general anesthesia: an observational study

BACKGROUND

The primary purpose of this study was to investigate the predictive value of alterations in cervical artery hemodynamic parameters induced by a simulated end-inspiratory occlusion test (sEIOT) measured by ultrasound for predicting postinduction hypotension (PIH) during general anesthesia.

METHODS

Patients undergoing gastrointestinal tumor resection under general anesthesia were selected for this study. Ultrasound has been utilized to assess hemodynamic parameters in carotid artery blood flow before induction, specifically focusing on variations in corrected flow time (ΔFTc) and peak blood flow velocity (ΔCDPV), both before and after sEIOT. Anesthesia was induced by midazolam, sufentanil, propofol, and rocuronium, and blood pressure (BP) and heart rate (HR) were recorded within the first 10 min following endotracheal intubation. PIH was defined as fall in systolic blood pressure (SBP) or mean arterial pressure (MAP) by > 30% of baseline or MAP to < 60 mm Hg.

RESULTS

The area under the receiver operating characteristic curves (AUC) for carotid artery ΔFTc was 0.88 (95%CI, 0.81 to 0.96; P < 0.001), and the optimal cutoff value was -16.57%, with a sensitivity of 91.4% and specificity of 77.60%. The gray zone for carotid artery ΔFTc was -16.34% to -15.36% and included 14% of the patients. The AUC for ΔCDPV was 0.54, with an optimal cutoff value of -1.47%. The sensitivity and specificity were calculated as 55.20% and 57.10%, respectively.

CONCLUSION

The corrected blood flow time changes in the carotid artery induced by sEIOT can predict hypotension following general anesthesia-induced hypotension, wherein ΔFTc less than 16.57% is the threshold.

TRIAL REGISTRATION

Chinese Clinical Trial Registry ( www.chictr.org.cn ; 20/06/2023; ChiCTR2300072632).