Postintubation Hypotension in General Anesthesia: A Retrospective Analysis

Hypotension after general anaesthesia induction using remimazolam or propofol in geriatric patients undergoing sevoflurane anaesthesia with remifentanil: a single-centre, double-blind, randomised controlled trial

BACKGROUND

The occurrence of hypotension after induction of general anaesthesia is common in geriatric patients, and should be prevented to minimise perioperative complications. Compared with propofol, remimazolam potentially has a lower incidence of hypotension. This study aimed to compare the incidence of hypotension after general anaesthesia induction with remimazolam or propofol in geriatric patients.

METHODS

This single-centre, double-blind, randomised trial enrolled 90 patients aged ≥80 yr who received general anaesthesia for scheduled surgery. Patients were randomised to receive remimazolam (12 mg kg-1 h-1) or propofol (0.025 mg kg-1 s-1) for anaesthesia induction, with remifentanil and sevoflurane. The presence or absence of hypertension on the ward served as the stratification factor. The incidence of hypotension after the induction of general anaesthesia, defined as a noninvasive mean arterial pressure of <65 mm Hg measured every minute from initiation of drug administration to 3 min after tracheal intubation, was the primary outcome. Subgroup analysis was performed for the primary outcome using preoperative ward hypertension, clinical frailty scale, Charlson Comorbidity Index, and age.

RESULTS

Three subjects were excluded before drug administration, and 87 subjects were included in the analysis. The incidence of hypotension was 72.1% (31/43) and 72.7% (32/44) with remimazolam or propofol, respectively. No statistically significant differences (adjusted odds ratio, 0.96; 95% confidence interval, 0.37-2.46; P=0.93) were observed between groups. Subgroup analysis revealed no significant differences between groups.

CONCLUSIONS

Compared with propofol, remimazolam did not reduce the incidence of hypotension after general anaesthesia induction in patients aged ≥80 yr.

CLINICAL TRIAL REGISTRATION

UMIN000042587.

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.

Predictive model for post-induction hypotension in patients undergoing transcatheter aortic valve implantation: a retrospective observational study

PURPOSE

Post-induction hypotension (PIH) is an independent risk factor for prolonged postoperative stay and hospital death. Patients undergoing transcatheter aortic valve implantation (TAVI) are prone to develop PIH. This study aimed to develop a predictive model for PIH in patients undergoing TAVI.

METHODS

This single-center retrospective observational study included 163 patients who underwent TAVI. PIH was defined as at least one measurement of systolic arterial pressure <90 mmHg or at least one incident of norepinephrine infusion at a rate >6 µg/min from anesthetic induction until 20 min post-induction. Multivariate logistic regression analysis was performed to develop a predictive model for PIH in patients undergoing TAVI.

RESULTS

In total, 161 patients were analyzed. The prevalence of PIH was 57.8%. Multivariable logistic regression analysis showed that baseline mean arterial pressure ≥90 mmHg [adjusted odds ratio (aOR): 0.413, 95% confidence interval (95% CI): 0.193-0.887; p=0.023] and higher doses of fentanyl (per 1-µg/kg increase, aOR: 0.619, 95% CI: 0.418-0.915; p=0.016) and ketamine (per 1-mg/kg increase, aOR: 0.163, 95% CI: 0.062-0.430; p=0.002) for induction were significantly associated with lower risk of PIH. A higher dose of propofol (per 1-mg/kg increase, aOR: 3.240, 95% CI: 1.320-7.920; p=0.010) for induction was significantly associated with higher risk of PIH. The area under the curve (AUC) for this model was 0.802.

CONCLUSION

The present study developed predictive models for PIH in patients who underwent TAVI. This model may be helpful for anesthesiologists in preventing PIH in patients undergoing TAVI.

Efficacy of remimazolam tosilate versus propofol for total intravenous anaesthesia in urological surgery: A randomised clinical trial

BACKGROUND

Remimazolam is a novel ultra-short-acting benzodiazepine sedative that acts on the gamma-aminobutyric acid type A receptor (GABAAR).

OBJECTIVE

To compare the efficacies of remimazolam (RMZ), and propofol (PROP) combined with remifentanil and cisatracurium for total intravenous anaesthesia (TIVA) in patients undergoing urological surgery.

DESIGN

A prospective, single-blind, randomised, noninferiority clinical trial.

SETTING

Single centre from 1 January 2022 to 30 March 2022.

PATIENTS

A total of 146 adult patients undergoing elective urological surgery.

INTERVENTION

Patients were randomly allocated in a 1 : 1 ratio to the PROP or RMZ groups. In the PROP group, anaesthesia was induced with propofol at 100 mg min -1 to reach a bispectral index score (BIS) of 40 to 60. After loss of consciousness (LOC), intravenous fentanyl 3 μg kg -1 was administered, followed by cisatracurium 0.3 mg kg -1 . Patients were intubated 3 min after cisatracurium administration. Anaesthesia was maintained with the combination of propofol (plasma concentration: 2.5 to 4 μg ml -1 ) and remifentanil (plasma concentration: 2.5 to 4 ng ml -1 ). In the RMZ group, anaesthesia was induced with remimazolam tosilate starting at 10 mg kg -1  h -1 to reach a BIS of 40 to 60 and maintained between 0.2 and 2 mg kg -1  h -1 . After LOC, fentanyl and cisatracurium were administered and intubation was performed as in the PROP group. Anaesthesia was maintained with a combination of remimazolam (0.2 to 2 mg kg -1  h -1 ) and remifentanil (plasma concentration: 2.5 to 4 ng ml -1 ).

MAIN OUTCOME MEASURES

The primary outcome was the TIVA success rate. The predefined noninferiority margin considered an absolute difference of 6% in the primary outcome between the groups. The secondary outcomes were vital signs, anaesthesia and surgery characteristics, and adverse events.

RESULTS

All patients completed the trial. The success rates of TIVA with remimazolam and propofol were 100 and 98.6%, respectively. The incidence of hypotension during anaesthesia was lower in the RMZ group (26%) than in the PROP group (46.6%) ( P  = 0.016). The median [IQR] total consumption of ephedrine during anaesthesia was higher in the PROP group 10 [0 to 12.5] mg than in the RMZ group 0 [0 to 10] mg ( P  = 0.0002). The incidence of injection pain was significantly higher in the PROP group (76.7%) than in the RMZ group (0; P  < 0.001). No significant differences in the controllability of the anaesthesia depth, anaesthesia and surgery characteristics, or vital signs were observed between the groups.

CONCLUSION

Remimazolam demonstrated noninferior efficacy to propofol combined with remifentanil and cisatracurium for TIVA in patients undergoing urological surgery.

TRIAL REGISTRATION

Chictr.org.cn, identifier: ChiCTR2100050923.

CLINICAL REGISTRATION

The study was registered in the Chinese Clinical Trial Registry (ChiCTR2100050923, Principal investigator: Xuehai Guan, Date of registration: 8 November 2021, https://www.chictr.org.cn/showproj.html?proj=133466 ).

Efficacy and safety of remimazolam compared with propofol in hypertensive patients undergoing breast cancer surgery: a single-center, randomized, controlled study

BACKGROUND

Remimazolam, as a novel anesthetic, has recently been shown to improve hemodynamic stability during anesthesia induction and maintenance; however, it has not been reported in the hypertensive population. This study aimed to compare the effects of remimazolam and propofol on hemodynamic stability in hypertensive patients undergoing breast cancer surgery.

METHODS

We enrolled 120 hypertensive patients undergoing breast cancer surgery in this prospective study and randomly allocated them to remimazolam (n = 60) or propofol (n = 60) groups. Anesthesia regimens were consistent between groups, except for the administration of remimazolam and propofol. Our primary outcome was the incidence of post-induction hypotension, which was either an absolute mean arterial pressure (MAP) < 60 mmHg or a > 30% relative drop in MAP compared to baseline within 20 min of induction or from induction to the start of surgery. Secondary outcomes included minimum MAP and MAP at different time points during anesthesia, the application of vasoactive drugs, adverse events, and the patient's self-reported Quality of Recovery-40 scale for the day after surgery.

RESULTS

The incidence of post-induction hypotension was lower and the minimum MAP during induction was higher in the remimazolam group than those in the propofol group. There were no significant differences between the two groups in the remaining outcomes.

CONCLUSION

Remimazolam is safe and effective in hypertensive patients undergoing breast cancer surgery. Induction with remimazolam in hypertensive patients may result in more stable hemodynamics than propofol.

TRIAL REGISTRATION

This study was registered at the Chinese Clinical Trials Registry ( http://www.chictr.org.cn ) on 03/12/2020, with registration number ChiCTR2000040579.

Effect of remimazolam vs. propofol on hemodynamics during general anesthesia induction in elderly patients: Single-center, randomized controlled trial

The current study aimed to compare the effects between remimazolam and propofol on hemodynamic stability during the induction of general anesthesia in elderly patients. We used propofol at a rate of 60 mg/(kg·h) in the propofol group (group P) or remimazolam at a rate of 6 mg/(kg·h) in the remimazolam group (group R) for the induction. A processed electroencephalogram was used to determine whether the induction was successful and when to stop the infusion of the study drug. We measured when patients entered the operating room (T 0), when the induction was successful (T 1), and when before (T 2) and 5 min after successful endotracheal intubation (T 3). We found that mean arterial pressure (MAP) was lower at T 1-3, compared with T 0 in both groups, but higher at T 2 in the group R, while ΔMAP T0-T2 and ΔMAP max were smaller in the group R (ΔMAP T0-T2: the difference between MAP at time point T 0 and T 2, ΔMAP max: the difference between MAP at time point T 0 and the lowest value from T 0 to T 3). Cardiac index and stroke volume index did not differ between groups, whereas systemic vascular resistance index was higher at T 1-3 in the group R. These findings show that remimazolam, compared with propofol, better maintains hemodynamic stability during the induction, which may be attributed to its ability to better maintain systemic vascular resistance levels.

A Nomogram Model for Post-Intubation Hypotension in Patients with Severe Pneumonia in the Emergency Department

Background

Post-intubation hypotension (PIH) frequently occurs in the management of critically ill patients and is associated with prognosis. The study aimed to construct a prediction model for PIH events by analyzing risk factors in patients with severe pneumonia in the emergency department.

Methods

We retrospectively enrolled 572 patients with severe pneumonia diagnosed in the emergency department of West China Hospital of Sichuan University. Five hundred patients with severe pneumonia who underwent endotracheal intubation were included in the study. All patients were randomized according to 7:3 and divided into a training cohort (n=351) and a validation cohort (n=149). Risk factors for PIH were analyzed using Least Absolute Shrinkage and Selection Operator (LASSO) and multivariable logistic regression. Calibration curves, receiver operating characteristic (ROC) curve, and decision curve analysis were applied to assess the predictive model's fitness, discrimination, and clinical utility.

Results

A total of 500 patients with severe pneumonia who underwent endotracheal intubation were enrolled in this study, and PIH occurred in 234 (46.8%) of these patients. Age, heart rate, systolic blood pressure, chronic obstructive pulmonary disease, acute physiology and chronic health evaluation II score, and induction agent use were identified as significant risk factors for the occurrence of PIH. Additionally, the body mass index was the opposite of the above. The area under the ROC curve (AUC) for the model was 0.856 (95% CI, 0.818-0.894) in the training cohort and 0.849 (95% CI, 0.788-0.910) in the validation cohort. The nomogram model was validated and demonstrated good calibration and high net clinical benefit. Finally, to facilitate application by clinicians, an online server has been set up which can be accessed free of charge via the website https://chinahospitals.shinyapps.io/DynNomapp/.

Conclusion

The nomogram is used for individualized prediction of patients with severe pneumonia prior to intubation and is simple to perform with high clinical value.

Hypotension Prediction Index and Incidence of Perioperative Hypotension: A Single-Center Propensity-Score-Matched Analysis

(1) Background: Intraoperative hypotension is common and is associated with increased morbidity and mortality. The Hypotension Prediction Index (HPI) is an advancement of arterial waveform analysis and allows preventive treatments. We used a propensity-score-matched study design to test whether application of the HPI reduces hypotensive events in non-cardiac surgery patients; (2) Methods: 769 patients were selected for propensity score matching. After matching, both HPI and non-HPI groups together comprised n = 136 patients. A goal-directed treatment protocol was applied in both groups. The primary endpoint was the incidence and duration of hypotensive events defined as MAP < 65 mmHg, evaluated by the time-weighted average (TWA) of hypotension. (3) Results: The median TWA of hypotension below 65 mmHg in the matched cohort was 0.180 mmHg (IQR 0.060, 0.410) in the non-HPI group vs. 0.070 mmHg (IQR 0.020, 0.240) in the HPI group (p < 0.001). TWA was higher in patients with ASA classification III/IV (0.170 mmHg; IQR 0.035, 0.365) than in patients with ASA status II (0.100; IQR 0.020, 0.250; p = 0.02). Stratification by intervention group showed no differences in the HPI group while TWA values in the non-HPI group were more than twice as high in patients with ASA status III/IV (p = 0.01); (4) Conclusions: HPI reduces intraoperative hypotension in a matched cohort seen for TWA below 65 mmHg and relative time in hypotension. In addition, non-HPI patients with ASA status III/IV showed a higher TWA compared with HPI-patients, indicating an advantageous effect of using HPI in patients at higher risk.

Sedation with a 1:1 mixture of etomidate and propofol for gastroscopy in hypertensive elderly patients

We hypothesized that the combined use of etomidate and propofol for endoscopic sedation in elderly hypertensive patients could reduce adverse reactions while providing ideal sedation. To validate our hypothesis, we conducted a prospective, randomized, controlled, double-blinded study. A total of 360 elderly hypertensive patients scheduled for gastroscopy at our hospital were enrolled in the study, of whom 328 completed the trial. The patients were randomly assigned to one of three groups: the propofol group (group P), the etomidate group (group E), or the propofol-etomidate combination group (mixed at a ratio of 1:1, group PE). We collected and analyzed the cardiopulmonary effects and side effects in each group. Regardless of the sedation drug used, the systolic blood pressure, mean blood pressure, and heart rate of involved patients were significantly affected. Oxygen desaturation and injection pain were more common in group P compared to groups E (33.6% vs. 14.8%, 31.8% vs. 2.7%, both P < 0.01) and group PE (33.6% vs. 13.6%, 31.8% vs. 6.4%, both P < 0.01). The incidence of myoclonus in the PE group was lower than that in the E group (10.9% vs. 61.2%, P < 0.01). Our results indeed demonstrated that the combined use of etomidate and propofol appeared to maintain cardiopulmonary stability with minimal side effects in older hypertensive patients scheduled for gastroscopy, which further implied that this sedation strategy could be a safe and pain-free option for managing patients undergoing gastroscopy, particularly those at a higher risk of adverse cardiovascular events.

Post-induction hypotension with remimazolam versus propofol in patients routinely administered angiotensin axis blockades: a randomized control trial

BACKGROUND

Certain routine medication could result in post-induction hypotension (PIH), such as angiotensin axis blockades, which are frequently administered as a first-line therapy against hypertension. Remimazolam is reportedly associated with lesser intraoperative hypotension than propofol. This study compared the overall incidence of PIH following remimazolam or propofol administration in patients managed by angiotensin axis blockades.

METHODS

This single-blind, parallel-group, randomized control trial was conducted in a tertiary university hospital in South Korea. Patients undergoing surgery with general anesthesia were considered for enrollment if the inclusion criteria were met: administration of an angiotensin converting enzyme inhibitor or angiotensin receptor blocker, 19 to 65 years old, American Society of Anesthesiologists physical status classification ≤ III, and no involvement in other clinical trials. The primary outcome was the overall incidence of PIH, defined as a mean blood pressure (MBP) < 65 mmHg or decrease by ≥ 30% of the baseline MBP. The time points of measurement were baseline, just before the initial intubation attempt, and 1, 5, 10, and 15 min following intubation. The heart rate, systolic and diastolic blood pressures, and bispectral index were also recorded. Groups P and R included patients administered propofol and remimazolam, respectively, as an induction agent.

RESULTS

A total of 81 patients were analyzed, of the 82 randomized patients. PIH was less frequent in group R than group P (62.5% versus 82.9%; t value 4.27, P = 0.04, adjusted odds ratio = 0.32 [95% confidence interval 0.10-0.99]). The decrease in the MBP from baseline was 9.6 mmHg lesser in group R than in group P before the initial intubation attempt (95% confidence interval 3.3-15.9). A similar trend was observed for systolic and diastolic blood pressures. No severe adverse events were observed in either group.

CONCLUSION

Remimazolam results in less frequent PIH than propofol in patients undergoing routine administration of angiotensin axis blockades.

TRIAL REGISTRATION

This trial was retrospectively registered on Clinical Research Information Service (CRIS), Republic of Korea (KCT0007488). Registration date: 30/06/2022.

Risk factors and predictive model for pulmonary complications in patients transferred to ICU after hepatectomy

OBJECTIVE

Postoperative pulmonary complications (PPCs) seriously harm the recovery and prognosis of patients undergoing surgery. However, its related risk factors in critical patients after hepatectomy have been rarely reported. This study aimed at analyzing the factors related to PPCs in critical adult patients after hepatectomy and create a nomogram for prediction of the PPCs.

METHODS

503 patients' data were collected form the Peking University People's Hospital. Multivariate logistic regression analysis was used to identify independent risk factors to derive the nomogram. Nomogram's discriminatory ability was assessed using the area under the receiver operating characteristic curve (AUC), and calibration was assessed using the Hosmer-Lemeshow goodness-of-fit test and calibration curve.

RESULTS

The independent risk factor for PPCs are advanced age (odds ratio [OR] = 1.026; P = 0.008), higher body mass index (OR = 1.139; P < 0.001), lower preoperative serum albumin level (OR = 0.961; P = 0.037), and intensive care unit first day infusion volume (OR = 1.152; P = 0.040). And based on this, we created a nomogram to predict the occurrence of PPCs. Upon assessing the nomogram's predictive ability, the AUC for the model was 0.713( 95% CI: 0.668-0.758, P<0.001). The Hosmer-Lemeshow test (P = 0.590) and calibration curve showed good calibration for the prediction of PPCs.

CONCLUSIONS

The prevalence and mortality of postoperative pulmonary complications in critical adult patients after hepatectomy are high. Advanced age, higher body mass index, lower preoperative serum albumin and intensive care unit first day infusion volume were found to be significantly associated with PPCs. And we created a nomogram model which can be used to predict the occurrence of PPCs.

Hypotension Prediction Index guided Goal Directed therapy and the amount of Hypotension during Major Gynaecologic Oncologic Surgery: a Randomized Controlled clinical Trial

Intraoperative hypotension (IOH) is associated with increased morbidity and mortality. Hypotension Prediction Index (HPI) is a machine learning derived algorithm that predicts IOH shortly before it occurs. We tested the hypothesis that the application of the HPI in combination with a pre-defined Goal Directed Therapy (GDT) hemodynamic protocol reduces IOH during major gynaecologic oncologic surgery. We enrolled women scheduled for major gynaecologic oncologic surgery under general anesthesia with invasive arterial pressure monitoring. Patients were randomized to a GDT protocol aimed at optimizing stroke volume index (SVI) or hemodynamic management based on HPI guidance in addition to GDT. The primary outcome was the amount of IOH, defined as the timeweighted average (TWA) mean arterial pressure (MAP) < 65 mmHg. Secondary outcome was the TWA-MAP < 65 mmHg during the first 20 min after induction of GA. After exclusion of 10 patients the final analysis included 60 patients (30 in each group). The median (25-75th IQR) TWA-MAP < 65 mmHg was 0.14 (0.04-0.66) mmHg in HPI group versus 0.77 (0.36-1.30) mmHg in Control group, P < 0.001. During the first 20 min after induction of GA, the median TWA-MAP < 65 mmHg was 0.53 (0.06-1.8) mmHg in the HPI group and 2.15 (0.65-4.2) mmHg in the Control group, P = 0.001. Compared to a GDT protocol aimed to SVI optimization, a machine learning-derived algorithm for prediction of IOH combined with a GDT hemodynamic protocol, reduced IOH and hypotension after induction of general anesthesia in patients undergoing major gynaecologic oncologic surgery.Trial registration number: NCT04547491. Date of registration: 10/09/2020.

Post-induction hypotension and intraoperative hypotension as potential separate risk factors for the adverse outcome: a cohort study

PURPOSE

Intraoperative hypotension (IOH) is associated with organ hypoperfusion. There are different underlying causes of IOH depending on the phase of surgery. Post-induction hypotension (PIH) and early-intraoperative hypotension tend to be frequently differentiated. We aimed to explore further different phases of IOH and verify whether they are differently associated with postoperative complications.

METHODS

Patients undergoing abdominal surgery between October 2018 and July 2019 in a university hospital were screened. Post-induction hypotension was defined as MAP ≤ 65 mmHg between the induction of anaesthesia and the onset of surgery. Hypotension during surgery (IOH) was defined as MAP ≤ 65 mmHg occurring between the onset of surgery and its completion. Acute kidney injury, stroke or transient ischaemic attack, delirium, and myocardial infarction were considered as the outcome.

RESULTS

We enrolled 508 patients (219 males, median age 62 years). 158 subjects (31.1%) met PIH, 171 (33.7%) met IOH criteria, and 67 (13.2%) patients experienced both. PIH time accounted for 22.8% of the total hypotension time and 29.7% of the IOH time. The IOH time accounted for 5.17% of the total intraoperative time, while PIH for 8.91% of the pre-incision time. Female sex, lower height, body mass and lower pre-induction BP (SBP and MAP) were found to be associated with the incidence of PIH. The negative outcome was observed in 38 (7.5%) patients. Intraoperative MAP ≤ 65 mmHg, longer duration of the procedure (≥ 230 min), chronic arterial hypertension and age were associated with the presence of the outcome (p < 0.01 each).

CONCLUSIONS

The presence of IOH defined as MAP ≤ 65 mmHg is relevant to post-operative organ complications, the presence of PIH does not appear to be of such significance. Because cumulative duration of PIH and IOH differs significantly, especially in long-lasting procedures, direct comparison of the influence of PIH and IOH on outcome separately may be biased and should be taken into account in data interpretation. Further research is needed to deeply investigate this phenomenon.

The difference in mean arterial pressure induced by remimazolam compared to etomidate in the presence of fentanyl at tracheal intubation: A randomized controlled trial

Background: Combined use of hypnotic and opioids during anesthesia inductions decreases blood pressure. Post-induction hypotension (PIHO) is the most common side effect of anesthesia induction. We aimed to compare the difference in mean arterial pressure (MAP) induced by remimazolam with that induced by etomidate in the presence of fentanyl at tracheal intubation. Methods: We assessed 138 adult patients with American Society of Anesthesiologists physical status I-II who underwent elective urological surgery. Patients were randomly allocated to receive either remimazolam or etomidate as alterative hypnotic in the presence of fentanyl during anesthesia induction. Comparable BIS values were achieved in both groups. The primary outcome was the difference in the MAP at tracheal intubation. The secondary outcomes included the characteristics of anesthesia, surgery, and adverse effects. Results: The MAP was higher in the etomidate group than in the remimazolam group at tracheal intubation (108 [22] mmHg vs. 83 [16] mmHg; mean difference, -26; 95% confidence interval [CI], -33 to -19; p < 0.0001). Heart rate was significantly higher in the etomidate group than in the remimazolam group at tracheal intubation. The patients' condition warranted the administration of ephedrine more frequently in the remimazolam group (22%) than in the etomidate group (5%) (p = 0.0042) during anesthesia induction. The remimazolam group had a lower incidence of hypertension (0% vs. 9%, p = 0.0133), myoclonus (0% vs. 47%, p < 0.001), and tachycardia (16% vs. 35%, p = 0.0148), and a higher incidence of PIHO (42% vs. 5%, p = 0.001) than the etomidate group during anesthesia induction. Conclusion: Remimazolam was associated with lower MAP and lower heart rate compared to etomidate in the presence of fentanyl at tracheal intubation. Patients in the remimazolam group had a higher incidence of PIHO, and their condition warranted the administration of ephedrine more frequently than in the etomidate group during anesthesia induction.

Hypotension after general anesthesia induction using remimazolam in geriatric patients: Protocol for a double-blind randomized controlled trial

Introduction

In geriatric patients, hypotension is often reported after general anesthesia induction using propofol. Remimazolam is a novel short-acting sedative. However, the incidence of hypotension after general anesthesia induction using remimazolam in geriatric patients remains unclear. This study aims to compare the incidence of hypotension associated with remimazolam and propofol in patients aged ≥80 years.

Methods

This single-center, double-blind, randomized, two-arm parallel group, standard treatment-controlled, interventional clinical trial will include 90 patients aged ≥80 years undergoing elective surgery under general anesthesia who will be randomized to receive remimazolam or propofol for induction. The primary outcome is the incidence of hypotension after general anesthesia induction, occurring between the start of drug administration and 3 min after intubation. We define hypotension as mean blood pressure <65 mmHg. The primary outcome will be analyzed using the full analysis set. The incidence of hypotension in the two groups will be compared using the Mantel-Haenszel χ2 test. Subgroup analysis of the primary outcome will be performed based on the Charlson comorbidity index, clinical frailty scale, hypertension in the ward, and age. Secondary outcomes will be analyzed using the Fisher’s exact test, Student’s t test, and Mann–Whitney U test, as appropriate. Logistic regression analysis will be performed to explore the factors associated with the incidence of hypotension after anesthesia induction.

Discussion

Our trial will determine the efficacy of remimazolam in preventing hypotension and provide evidence on the usefulness of remimazolam for ensuring hemodynamic stability during general anesthesia induction in geriatric patients.

Trial registration

The study has been registered with UMIN Clinical Trials Registry (UMIN000042587), on June 30, 2021.

Prediction of post-induction hypotension by point-of-care echocardiography: A prospective observational study

BACKGROUND

Post-induction hypotension (PIH) is a common side effect of general anaesthesia and is associated with poor perioperative outcomes. We assessed the ability of two point-of-care echocardiographic variables to predict the occurrence of PIH: the passive leg raising-induced changes in the velocity-time integral of the left ventricular outflow tract (ΔVTI-PLR) and the inferior vena cava collapsibility index (IVC-CI).

METHODS

We studied 64 patients > 50 years scheduled for elective abdominal surgery. ΔVTI-PLR and IVC-CI were prospectively obtained before general anaesthesia induction. PIH was defined by a systolic arterial pressure < 90 mmHg or a mean arterial pressure < 65 mmHg or by a decrease in systolic or mean arterial pressure > 30% from pre-induction level. Intraclass correlation coefficients (ICCs) were calculated to assess the reproducibility of echocardiographic measurements. Receiver operating characteristic (ROC) curves with 95% confidence intervals (CIs) were generated to test the ability of ΔVTI-PLR and IVC-CI to predict the occurrence of PIH.

RESULTS

PIH occurred in 33 (51%) patients. The ICCs for VTI and IVC measurements showed excellent reproducibility. The occurrence of PIH was accurately predicted by ΔVTI-PLR with an area under the ROC curve (AUROC) of 0.89 (95% CI: 0.80-0.97), a threshold value of 18% with a sensitivity of 88% (95% CI: 71-97%) and a specificity of 84% (95% CI: 66-94%). The occurrence of PIH was poorly predicted by IVC-CI with an AUROC of 0.68 (95% CI: 0.54-0.80) and a threshold value of 42%.

CONCLUSIONS

ΔVTI-PLR, unlike IVC-CI, could reliably predict the occurrence of PIH. The use of ΔVTI-PLR could help individualise anaesthesia management to prevent PIH.

Hemodynamic monitoring with Hypotension Prediction Index versus arterial waveform analysis alone and incidence of perioperative hypotension

BACKGROUND

Intraoperative hypotension is associated with increased morbidity and mortality. The Hypotension Prediction Index (HPI) is an advancement of the arterial waveform analysis to predict intraoperative hypotension minutes before episodes occur enabling preventive treatments. We tested the hypothesis that the HPI combined with a personalized treatment protocol reduces intraoperative hypotension when compared to arterial waveform analysis alone.

METHODS

We conducted a retrospective analysis of 100 adult consecutive patients undergoing moderate- or high-risk noncardiac surgery with invasive arterial pressure monitoring using either index guidance (HPI) or arterial waveform analysis (FloTrac) depending on availability (FloTrac, n = 50; HPI, n = 50). A personalized treatment protocol was applied in both groups. The primary endpoint was the incidence and duration of hypotensive events defined as MAP <65 mmHg evaluated by time-weighted average of hypotension.

RESULTS

In the FloTrac group, 42 patients (84%) experienced a hypotension while in the HPI group 26 patients (52%) were hypotensive (p = 0.001). The median (IQR) time-weighted average of hypotension in the FloTrac group was 0.27 (0.42) mmHg versus 0.10 (0.19) mmHg in the HPI group (p = 0.001). Finally, the median duration of each hypotensive event (IQR) was 2.75 (2.40) min in the FloTrac group compared to 1.00 (2.06) min in the HPI group (p = 0.002).

CONCLUSIONS

The application of the HPI combined with a personalized treatment protocol can reduce incidence and duration of hypotension when compared to arterial waveform analysis alone. This study therefore provides further evidence of the transition from prediction to actual prevention of hypotension using HPI.

Observer's Assessment of Alertness/Sedation-based titration reduces propofol consumption and incidence of hypotension during general anesthesia induction: A randomized controlled trial

Administration of a single propofol bolus dose for anesthesia induction causes hypotension. We included 160 patients (74 males and 86 females; mean age, 42.4 ± 10.7 [range: 18-60] years) with the American Society of Anesthesiologists status I-II undergoing elective surgery under general anesthesia. Using simple randomization, the patients were divided into a conventional group (n = 80; received 2 mg/kg propofol at a rate of 250 mg/min) and titrated group (n = 80; received propofol at a rate of 1 mg/kg/min until the Observer's Assessment of Alertness/Sedation scale score reached 1 point). Fentanyl (4 µg/kg) and cisatracurium (0.2 mg/kg) were administered, as appropriate. Systolic blood pressure, diastolic blood pressure, mean blood pressure, and heart rate were recorded at different time points. Propofol consumption, hypotension, and other adverse events were recorded. All the patients were intubated without awareness. Compared with the conventional group, the titrated group showed more stable blood pressure (p < 0.05), as well as a lower decrease in systolic blood pressure, mean blood pressure at 1 and 3 min, and diastolic blood pressure at 1 min after propofol administration (p < 0.01). Moreover, compared with the conventional group, the titrated group showed a lower post-intubation hypotension incidence (9 vs. 19 cases; p = 0.04), as well as lower total propofol dosage and propofol dose per kilogram of body weight (93.57 ± 14.40 mg vs. 116.80 ± 22.37 mg and 1.73 ± 0.27 mg/kg vs. 2.02 ± 0.08 mg/kg, respectively, p < 0.01). Compared with conventional propofol usage, titrated propofol administration can reduce the incidence of hypotension and propofol consumption during anesthesia induction.

Intraoperative management and hemodynamic monitoring for ma- jor abdominal surgery : a narrative review

Background : Several trials suggest that postoperative outcomes may be improved by the use of hemodynamic monitoring, but a survey by the American Society of Anesthesiologists (ASA) and the European Society of Anaesthesiology (ESA) showed that cardiac output is monitored by only 34% of ASA and ESA respondents and central venous pressure is monitored by 73% of ASA respondents and 84% of ESA respondents. Moreover, 86.5% of ASA respondents and 98.1% of ESA respondents believe that their current hemodynamic management could be improved (1). The interaction of general anesthesia and surgical stress is the main problem and the leading cause for postoperative morbidity and mortality. The choice of a suitable hemodynamic monitoring system for patients at high anesthesiological risk is of crucial importance to reduce the incidence of major postoperative complications. The aim of the present review is to summarize the benefits of a defined path beginning before surgery, and discuss the available evidence supporting the efficacy and safety of an individualized hemodynamic approach for major abdominal surgery. Objective : To evaluate the clinical effectiveness of a perioperative hemodynamic therapy algorithm in high risk patients

Intraoperative hypotension and complications after vascular surgery: A scoping review

BACKGROUND

Intraoperative hypotension during major surgery is associated with adverse health outcomes. This phenomenon represents a potentially important therapeutic target for vascular surgery patients, who may be uniquely vulnerable to intraoperative hypotension. This review summarizes current evidence regarding the impact of intraoperative hypotension on postoperative complications in patients undergoing vascular surgery, focusing on potentially modifiable procedure- and patient-specific risk factors.

METHODS

A scoping review of the literature from Embase, MEDLINE, and PubMed databases was conducted from inception to December 2019 to identify articles related to the effects of intraoperative hypotension on patients undergoing vascular surgery.

RESULTS

Ninety-two studies met screening criteria; 9 studies met quality and inclusion criteria. Among the 9 studies that defined intraoperative hypotension objectively, there were 9 different definitions. Accordingly, the reported incidence of intraoperative hypotension ranged from 8% to 88% (when defined as a fall in systolic blood pressure of >30 mm Hg or mean arterial pressure <65). The results demonstrated that intraoperative hypotension is an independent risk factor for longer hospital length of stay, myocardial injury, acute kidney injury, postoperative mechanical ventilation, and early mortality. Vascular surgery patients with comorbid conditions that confer increased vulnerability to hypoperfusion and ischemia appear to be susceptible to the adverse effects of intraoperative hypotension.

CONCLUSION

There is no validated, consensus definition of intraoperative hypotension or other hemodynamic parameters associated with increased risk for adverse outcomes. Despite these limitations, the weight of evidence suggests that intraoperative hypotension is common and associated with major postoperative complications in vascular surgery patients.

Assessing the validity of a linear inflation method in noninvasive blood pressure monitoring during the induction period of general anaesthesia

Inflationary noninvasive blood pressure (iNIBP) monitoring can determine BP in a shorter time compared to conventional deflationary NIBP (dNIBP) monitoring. We assessed the efficacy of iNIBP monitoring during induction of general anaesthesia and tracheal intubation, which can cause rapid changes in haemodynamics. Our study included 14 surgery patients receiving tracheal intubation under general anaesthesia. Blood pressure was continuously measured using iNIBP monitoring. We recorded the percentage of successful iNIBP monitoring (measurements made without switching to dNIBP mode) during anaesthesia induction. We obtained 326 BP-measurements from 14 patients. The iNIPB mode was able to perform 90.9% of the measurements during the induction of general anaesthesia. iNIBP could determine BP even during periods of high blood pressure variability (31.6% [interquartile range; 22-40]). Our results validate the utility of iNIBP monitoring during the induction period of general anaesthesia, despite the rapid haemodynamic changes.

Hypotension Prediction Index for Prevention of Hypotension during Moderate- to High-risk Noncardiac Surgery

Background

The Hypotension Prediction Index is a commercially available algorithm, based on arterial waveform features, that predicts hypotension defined as mean arterial pressure less than 65 mmHg for at least 1 min. We therefore tested the primary hypothesis that index guidance reduces the duration and severity of hypotension during noncardiac surgery.

Methods

We enrolled adults having moderate- or high-risk noncardiac surgery with invasive arterial pressure monitoring. Participating patients were randomized to hemodynamic management with or without index guidance. Clinicians caring for patients assigned to guidance were alerted when the index exceeded 85 (range, 0 to 100) and a treatment algorithm based on advanced hemodynamic parameters suggested vasopressor administration, fluid administration, inotrope administration, or observation. Primary outcome was the amount of hypotension, defined as time-weighted average mean arterial pressure less than 65 mmHg. Secondary outcomes were time-weighted mean pressures less than 60 and 55 mmHg.

Results

Among 214 enrolled patients, guidance was provided for 105 (49%) patients randomly assigned to the index guidance group. The median (first quartile, third quartile) time-weighted average mean arterial pressure less than 65 mmHg was 0.14 (0.03, 0.37) in guided patients versus 0.14 (0.03, 0.39) mmHg in unguided patients: median difference (95% CI) of 0 (–0.03 to 0.04), P = 0.757. Index guidance therefore did not reduce amount of hypotension less than 65 mmHg, nor did it reduce hypotension less than 60 or 55 mmHg. Post hoc, guidance was associated with less hypotension when analysis was restricted to episodes during which clinicians intervened.

Conclusions

In this pilot trial, index guidance did not reduce the amount of intraoperative hypotension. Half of the alerts were not followed by treatment, presumably due to short warning time, complex treatment algorithm, or clinicians ignoring the alert. In the future we plan to use a lower index alert threshold and a simpler treatment algorithm that emphasizes prompt treatment.

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Risk factors for and prediction of post-intubation hypotension in critically ill adults: A multicenter prospective cohort study

Objective

Hypotension following endotracheal intubation in the ICU is associated with poor outcomes. There is no formal prediction tool to help estimate the onset of this hemodynamic compromise. Our objective was to derive and validate a prediction model for immediate hypotension following endotracheal intubation.

Methods

A multicenter, prospective, cohort study enrolling 934 adults who underwent endotracheal intubation across 16 medical/surgical ICUs in the United States from July 2015-January 2017 was conducted to derive and validate a prediction model for immediate hypotension following endotracheal intubation. We defined hypotension as: 1) mean arterial pressure <65 mmHg; 2) systolic blood pressure <80 mmHg and/or decrease in systolic blood pressure of 40% from baseline; 3) or the initiation or increase in any vasopressor in the 30 minutes following endotracheal intubation.

Results

Post-intubation hypotension developed in 344 (36.8%) patients. In the full cohort, 11 variables were independently associated with hypotension: increasing illness severity; increasing age; sepsis diagnosis; endotracheal intubation in the setting of cardiac arrest, mean arterial pressure <65 mmHg, and acute respiratory failure; diuretic use 24 hours preceding endotracheal intubation; decreasing systolic blood pressure from 130 mmHg; catecholamine and phenylephrine use immediately prior to endotracheal intubation; and use of etomidate during endotracheal intubation. A model excluding unstable patients’ pre-intubation (those receiving catecholamine vasopressors and/or who were intubated in the setting of cardiac arrest) was also developed and included the above variables with the exception of sepsis and etomidate. In the full cohort, the 11 variable model had a C-statistic of 0.75 (95% CI 0.72, 0.78). In the stable cohort, the 7 variable model C-statistic was 0.71 (95% CI 0.67, 0.75). In both cohorts, a clinical risk score was developed stratifying patients’ risk of hypotension.

Conclusions

A novel multivariable risk score predicted post-intubation hypotension with accuracy in both unstable and stable critically ill patients.

Study registration

Clinicaltrials.gov identifier: NCT02508948 and Registered Report Identifier: RR2-10.2196/11101.

Effect of Ketamine/Propofol Admixture on Peri-Induction Hemodynamics: A Systematic Review and Meta-Analysis

To evaluate the effectiveness of an admixture of ketamine and propofol on peri-induction hemodynamics during airway manipulation, we searched electronic databases of randomized controlled trials from January 1, 2000, to October 17, 2018. Trial screening, selection, and data extraction were done independently by two reviewers with outcomes pooled across included trials using the random-effects model. We included 10 randomized trials (722 patients, mean age of 53.99 years, 39.96% female). American Society of Anesthesiologists physical status was reported in 9 trials with classes I and II representing the majority. Ketamine/propofol admixture was associated with a nonsignificant increase in heart rate (weighted mean difference, 3.36 beats per minute (95% CI, -0.88, 7.60), I 2 = 88.6%), a statistically significant increase in systolic blood pressure (weighted mean difference, 9.67 mmHg (95% CI, 1.48, 17.86), I 2 = 87.2%), a nonsignificant increase in diastolic blood pressure (weighted mean difference, 2.18 mmHg (95% CI, -2.82, 7.19), I 2 = 73.1%), and a nonsignificant increase in mean arterial pressure (weighted mean difference, 3.28 mmHg (95% CI, -0.94, 7.49), I 2 = 69.9%) compared to other agents. The risk of bias was high and the certainty of evidence was low. In conclusion, among patients undergoing airway manipulation and needing sedation, the use of a ketamine/propofol admixture may be associated with better hemodynamics compared to nonketamine/propofol sedation. This trial is registered with CRD42019125725.

Hypotension Prediction Index software for management of hypotension during moderate- to high-risk noncardiac surgery: protocol for a randomized trial

BACKGROUND

Hypotension is associated with serious complications, including myocardial infarction, acute kidney injury, and mortality. Consequently, predicting and preventing hypotension may improve outcomes. We will therefore determine if use of a novel hypotension prediction tool reduces the duration and severity of hypotension in patients having non-cardiac surgery.

METHODS/DESIGN

We will conduct a two-center, pragmatic, randomized controlled trial (N = 213) in noncardiac surgical patients > 45 years old who require intra-arterial blood pressure monitoring. All participating patients will be connected to a Flortrac IQ sensor and EV1000 platform (Edwards Lifesciences, Irvine). They will be randomly assigned to blinded or unblinded arms. The Hypotension Prediction Index (HPI) and advanced hemodynamic information will be universally recorded, but will only be available to clinicians when patients are assigned to unblinded monitoring. The primary outcome will be the effect of HPI software guidance on intraoperative time-weighted average mean arterial pressure under a threshold of 65 mmHg, which will be assessed with a Wilcoxon-Mann-Whitney 2-sample, two-tailed test.

DISCUSSION

Our trial will determine whether the Hypotension Prediction Index and associated hemodynamic information substantively reduces hypotension during non-cardiac surgery.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03610165 . Registered on 1 August 2018.

Shock Index as a Predictor of Post-Intubation Hypotension and Cardiac Arrest; A Review of the Current Evidence

Endotracheal intubation is a lifesaving procedure that is performed in various settings within the hospital or even in the pre-hospital field. However, it can result in serious hemodynamic complications, such as post-intubation hypotension (PIH) and cardiac arrest. The most promising predictor of such complications is the shock index (SI), which holds great prognostic value for multiple disorders. On the other hand, most of the studies that have assessed the predictability of the pre-intubation SI have been small and were limited to a particular setting of a single center; thus, the results were not generalizable, and the predictive value vary according to the setting. This review comprehensively assessed the utility of the pre-intubation SI for predicting PIH and post-intubation cardiac arrest by classifying and comparing evidence compiled from various settings, such as pre-hospital settings, emergency departments (EDs), intensive care units (ICUs), and operating rooms (ORs). The vast majority of these studies, conducted in ED and ICU settings, which revealed a significant correlation between an elevated SI and PIH or post-intubation cardiac arrest. The reliability and simplicity of obtaining a pre-intubation SI value are important considerations that encourage the extension of its use to all in-hospital intubations. Further studies are required to assess the predictive value of the SI in the pre-hospital setting.

Sedative dose and patient variable impacts on postintubation hypotension in emergency airway management

PURPOSE

Postintubation hypotension (PIH) is an adverse event associated with poor outcomes in emergency department (ED) endotracheal intubation. This study aimed to evaluate the association between sedative dose adjustment and PIH during emergency airway management. We also investigated the impact of patient and procedural factors on the incidence of PIH.

MATERIALS AND METHODS

This was a single-center, retrospective study that used a prospectively collected registry of airway management performed at the ED from April 2014 to February 2017. Adult patients who received emergency endotracheal intubation were included. Multivariable logistic regression models were used to evaluate the association of PIH with sedative dose, patient variables, and procedural variables.

RESULTS

Overall, 689 patients were included, and 233 (33.8%) patients developed PIH. In the patients overall, multivariable logistic regression demonstrated that age > 70 years, shock index >0.8, arterial acidosis (pH < 7.2), intubation indication, and use of non-depolarizing neuromuscular blocking agent were significantly related to PIH. In patients overall, the sedative dose was not related to PIH (overdose; OR: 1.09, 95%CI: 0.57-2.06), (reduction; OR: 0.93, 95%CI: 0.61-1.42), (none used; OR: 1.28, 95%CI: 0.64-2.53). In subgroup analysis, ketamine dose was not related to PIH (overdose; OR: 0.81, 95%CI: 0.27-2.38, reduction; OR: 1.41, 95%CI: 0.78-2.54). Reduction of etomidate dose was significantly associated with decreased PIH (reduction; OR: 0.46, 95%CI: 0.22-0.98, overdose; OR: 1.77, 95%CI: 0.79-3.93).

CONCLUSIONS

PIH was mainly related to predisposing patient-related factors. Only adjustment of etomidate dose was associated with the incidence of PIH.

The association of hypotension during non-cardiac surgery, before and after skin incision, with postoperative acute kidney injury: a retrospective cohort analysis

Intra-operative hypotension is associated with acute postoperative kidney injury. It is unclear how much hypotension occurs before skin incision compared with after, or whether hypotension in these two periods is similarly associated with postoperative kidney injury. We analysed the association of mean arterial pressure < 65 mmHg with postoperative kidney injury in 42,825 patients who were anaesthetised for elective non-cardiac surgery. Intra-operative hypotension occurred in 30,423 (71%) patients: 22,569 (53%) patients before skin incision; and 24,102 (56%) patients after incision. Anaesthetised patients who were hypotensive had mean arterial pressures < 65 mmHg for a median (IQR [range]) of 5.5 (0.0-14.7 [0.0-60.0]) min.h^-1 before skin incision, compared with 1.7 [0.3-5.1 [0.0-57.5]) min.h^-1 after incision: a median (IQR [range]) of 36% (0%-84% [0%-100%]) of hypotensive readings were before incision. We diagnosed postoperative kidney injury in 2328 (5%) patients. The odds ratio (95%CI) for acute kidney injury was 1.05 (1.02-1.07) for each doubling of the duration of hypotension, p < 0.001. Postoperative kidney injury was associated with the product of hypotension duration and severity, that is, area under the curve, before skin incision and after, odds ratio (95%CI): 1.02 (1.01-1.04), p = 0.004; and 1.02 (1.00-1.04), p = 0.016, respectively. A substantial fraction of all hypotension happened before surgical incision and was thus completely due to anaesthetic management. We recommend that anaesthetists should avoid mean arterial pressure < 65 mmHg during surgery, especially after induction, assuming that its association with postoperative kidney injury is, at least in part, causal.

Could resuscitative endovascular balloon occlusion of the aorta improve survival among severely injured patients with post-intubation hypotension?

Current literature shows the association of post-intubation hypotension and increased odds of mortality in critically ill non-trauma and trauma populations. However, there is a lack of research on potential interventions that can prevent or ameliorate the consequences of endotracheal intubation and thus improve the prognosis of trauma patients with post-intubation hypotension. This review paper hypothesizes that the deployment of REBOA among trauma patients with PIH, by its physiologic effects, will reduce the odds of mortality in this population. The objective of this paper is to review the current literature on REBOA and post-intubation hypotension, and, furthermore, to provide a rational hypothesis on the potential role of REBOA in severely injured patients with post-intubation hypotension.