The use of remimazolam versus propofol for induction and maintenance of general anesthesia: A systematic review and meta-analysis

Background: The primary objective of this study was to compare the risk of hypotension, as well as the induction and recovery characteristics between remimazolam and propofol in patients receiving surgery under general anesthesia. Methods: The Embase, Medline, Google scholar, and the Cochrane Library databases were searched from inception to March 2022 for randomized controlled trials The primary outcome was the risk of post-induction hypotension between the two agents, while the secondary outcomes included anesthetic depth, induction efficacy, time to loss of consciousness (LOC), hemodynamic profiles, time to eye opening, extubation time as well as the incidence of injection pain and postoperative nausea/vomiting (PONV). Results: Meta-analysis of eight studies published from 2020 to 2022 involving 738 patients revealed a significantly lower risk of post-induction hypotension with the use of remimazolam compared to that with propofol [risk ratio (RR) = 0.57, 95% confidence interval (CI): 0.43 to 0.75, p < 0.0001, I2 = 12%, five studies, 564 patients]. After anesthetic induction, the anesthetic depth measured by bispectral index (BIS) was lighter in the remimazolam group than that in the propofol group (MD = 9.26, 95% confidence interval: 3.06 to 15.47, p = 0.003, I2 = 94%, five studies, 490 patients). The time to loss of consciousness was also longer in the former compared to the latter (MD = 15.49 s, 95%CI: 6.53 to 24.46, p = 0.0007, I2 = 61%, three studies, 331 patients). However, the use of remimazolam correlated with a lower risk of injection pain (RR = 0.03, 95%CI: 0.01 to 0.16, p < 0.0001, I2 = 0%, three studies, 407 patients) despite comparable efficacy of anesthetic induction (RR = 0.98, 95%CI: 0.9 to 1.06, p = 0.57, I2 = 76%, two studies, 319 patients). Our results demonstrated no difference in time to eye opening, extubation time, and risk of PONV between the two groups. Conclusion: Remimazolam was associated with a lower risk of post-induction hypotension after anesthetic induction compared with propofol with similar recovery characteristics. Further studies are required to support our findings. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/; Identifier: CRD42022320658.

Comparison of paravertebral block vs. general anesthesia for percutaneous nephrolithotomy: A retrospective study

Background

General anesthesia is used in the majority of patients undergoing percutaneous nephrolithotomy. To reduce the general anesthesia-related risks and complications, this study evaluated the efficacy and safety of the paravertebral block as a novel and alternative anesthetic method for percutaneous nephrolithotomy.

Methods

This was a retrospective study. A total of 198 patients under percutaneous nephrolithotomy were included. Among them, 76 patients received paravertebral block and 122 received general anesthesia. Patients' characteristics, surgical outcomes, anesthetic outcomes, and perioperative complications and the visual analog scale (VAS) were recorded to evaluate the efficacy and safety of paravertebral block compared with general anesthesia. Intergroup differences of the parameters were analyzed using an independent t-test and χ²-tests appropriate.

Results

Seventy-six patients who underwent paravertebral block completed the surgery successfully, three patients were supplemented with propofol for discomfort during ureteroscopy, and two patients were supplemented with remifentanil for incomplete nerve blockade. Patients who underwent paravertebral block had a higher American Society of Anesthesiologists grade and heart function grade, including patients with contraindications to general anesthesia. Intraoperative and postoperative adverse events and the anesthesia costs were less in patients who underwent paravertebral block. VAS pain scores during the postoperative period in patients who underwent paravertebral block were lower than those in patients who underwent general anesthesia without the use of patient-controlled intravenous analgesia.

Conclusion

In this retrospective study, paravertebral block was found to be effective and safe in providing intraoperative anesthesia for percutaneous nephrolithotomy, and had less adverse events and anesthesia costs. Paravertebral block is an attractive alternative anesthesia for patients at increased risk of comorbidities following general or neuraxial anesthesia.

The efficacy and safety of asleep and awake subthalamic deep brain stimulation for Parkinson's disease patients: A 1-year follow-up

Introduction

Traditional DBS is usually conducted under local anesthesia (LA) which is intolerable to some patients, DBS under general anesthesia (GA) was opted to extended surgical indication. This study aimed to compare the efficacy and safety of bilateral subthalamic deep brain stimulation (STN-DBS) for Parkinson's disease (PD) under asleep and awake anesthesia state in 1-year postoperative follow-up.

Methods

Twenty-one PD patients were assigned to asleep group and 25 patients to awake group. Patients received bilateral STN-DBS under different anesthesia state. The PD participants were interviewed and assessed preoperatively and at 1-year postoperative follow-up.

Results

At 1-year follow-up, compared surgical coordinate in two groups, the left-side Y of asleep group showed more posterior than awake group (Y was-2.39 ± 0.23 in asleep group, -1.46 ± 0.22 in awake group, p = 0.007). Compared with preoperative OFF MED state, MDS-UPDRS III scores in OFF MED/OFF STIM state remained unchanged, while in OFF MED/ON STIM state were significantly improved in awake and asleep groups, yet without significant difference. Compared with preoperative ON MED state, MDS-UPDRS III scores in ON MED/OFF STIM, and ON MED/ON STIM state remained unchanged in both groups. In non-motor outcomes, PSQI, HAMD, and HAMA score significantly improved in asleep group compared to awake group at 1-year follow-up (PSQI, HAMD, and HAMA score in 1-year follow-up were 9.81 ± 4.43; 10.00 ± 5.80; 5.71 ± 4.75 in awake group, 6.64 ± 4.14; 5.32 ± 3.78; 3.76 ± 3.87 in asleep group, p = 0.009; 0.008; 0.015, respectively), while there was no significant difference in PDQ-39, NMSS, ESS, PDSS score, and cognitive function. Anesthesia methods was significantly associated with improvement of HAMA and HAMD score (p = 0.029; 0.002, respectively). No difference in LEDD, stimulation parameters and adverse events was observed between two groups.

Discussion

Asleep STN-DBS may be considered a good alternative method for PD patients. It is largely consistent with awake STN-DBS in motor symptoms and safety. Yet, it showed higher improvement in terms of mood and sleep compared to awake group at 1-year follow-up.

Clinical Study of Intraoperative Microelectrode Recordings during Awake and Asleep Subthalamic Nucleus Deep Brain Stimulation for Parkinson's Disease: A Retrospective Cohort Study

Our objective is to analyze the difference of microelectrode recording (MER) during awake and asleep subthalamic nucleus deep brain stimulation (STN-DBS) for Parkinson’s disease (PD) and the necessity of MER during “Asleep DBS” under general anesthesia (GA). The differences in MER, target accuracy, and prognosis under different anesthesia methods were analyzed. Additionally, the MER length was compared with the postoperative electrode length by electrode reconstruction and measurement. The MER length of two groups was 5.48 ± 1.39 mm in the local anesthesia (LA) group and 4.38 ± 1.43 mm in the GA group, with a statistical significance between the two groups (p < 0.01). The MER length of the LA group was longer than its postoperative electrode length (p < 0.01), however, there was no significant difference between the MER length and postoperative electrode length in the GA group (p = 0.61). There were also no significant differences in the postoperative electrode length, target accuracy, and postoperative primary and secondary outcome scores between the two groups (p > 0.05). These results demonstrate that “Asleep DBS” under GA is comparable to “Awake DBS” under LA. GA has influences on MER during surgery, but typical STN discharges can still be recorded. MER is not an unnecessary surgical procedure.

The Impact of Local vs. General Anesthesia in Patients Undergoing Thoracic Endovascular Aortic Surgery

OBJECTIVE

General anesthesia is associated with inherent risks that can be avoided by the use of lesser invasive anesthetic strategies. We hypothesize that examine and compare the use of local or regional anesthesia (LRA to general anesthesia (GA) in patients undergoing thoracic endovascular aortic repair (TEVAR).

METHODS

Patients undergoing TEVAR between 2010-2020 in the Vascular Quality Initiative were analyzed. Exclusion criteria included receipt of branched or physician modified endografts and devices extending distally beyond Zone 5. Patients were categorized as receiving LRA or GA. Center volume was reported by quartile according to annualized TEVAR volume and operative outcomes were compared using appropriate frequentists tests. Univariable and multivariable regression models for anesthesia type and operative outcomes were created to compare unadjusted and adjusted rates of each outcome. Long-term survival was estimated using a Kaplan-Meier survival estimator, while adjusted survival analysis was performed using a Cox proportional-hazards model.

RESULTS

Of the 17,099 patients who underwent TEVAR, 7,299 met the inclusion and exclusion criteria. Of these, 3.8% received LRA. There were no significant differences in the annual proportion of patients who received LRA from 2011 to 2020 (p = 0.49, Chi-square test for trend). Only 18.8% of patients who received LRA were treated at the highest quartile volume centers. Patients who received LRA were older and more comorbid compared to those who received GA. There were no differences in in-hospital mortality (OR = 0.79, 95% CI 0.42 to 1.38, p = 0.44) or composite of any complication (OR = 0.79, 95% CI 0.54 to 1.14, p = 0.22) between patients who received LRA compared to GA. This also applied to patients presenting with rupture. Receipt of LRA was associated with lower odds of post-operative congestive heart failure (OR = 0.19, 95% CI 0.01 to 0.89, p = 0.01) as well as decreased length of ICU (OR = 0.54, 95% CI 0.40 to 0.72, p < 0.01) and hospital length of stay (OR = 0.64, 95% CI 0.46 to 0.84, p < 0.01). LRA was not associated with decreased long-term survival compared to GA (HR 0.95, 95% CI 0.72 to 1.25, p = 0.72).

CONCLUSION

Despite a greater number of baseline comorbidities, patients undergoing TEVAR with LRA experienced shorter ICU and post-operative lengths of stay, with similar operative outcomes and long-term survival compared to patients who received GA.. Similar findings were found amongst the rupture cohort. LRA should be considered more frequently in select patients undergoing TEVAR.

Using Local Anesthesia for Burr Hole Surgery of Chronic Subdural Hematoma Reduces Postoperative Complications, Length of Stay, and Hospitalization Cost: A Retrospective Cohort Study From a Single Center

PURPOSE

The purpose of the current study was to compare the effects of local anesthesia (LA) and general anesthesia (GA) on the surgical process and postoperative recovery of patients with unilateral chronic subdural hematoma (CSDH).

PATIENTS AND METHODS

A retrospective cohort study was conducted on patients with unilateral CSDH who underwent burr hole surgery between the years 2013 and 2018. Patients who received local anesthesia were allocated to the LA group, and the patients who received general anesthesia were allocated to the GA group. The clinical data, postoperative complication, length of stay, and hospitalization cost of these two groups were compared and analyzed.

RESULTS

Data from 105 patients was collected for this study. Fifty one patients were assigned to the LA group and 54 to GA group. The duration of anesthesia and operation of the LA group was 37.71 (10.55) min; while for the GA group the duration was 56.04 (8.37) min (p < 0.001). The time from operation to discharge in GA group was greatly longer than that in LA group [(8.51 (1.49) days vs. 10.46 (2.34) days, respectively; p < 0.001]. Hospitalization cost for LA group was 2,721.54 (504.66) USD, which was significantly lesser than that for GA patients [3,314.82 (493.52) USD; p < 0.001]. The total number of complications in LA patients was less than that in GA patients [6 vs. 29 cases, respectively; p < 0.001]. The number of patients with residual hematoma in the LA group was <that in the GA group (p = 0.014).

CONCLUSION

As compared to GA, LA might be a simpler, safer, and more effective method for burr hole surgery of CSDH to promote patients' recovery. However, further research is still required to confirm this conclusion.

Anesthesia Techniques and Long-Term Oncological Outcomes

Despite advances in cancer treatments, surgery remains one of the most important therapies for solid tumors. Unfortunately, surgery promotes angiogenesis, shedding of cancer cells into the circulation and suppresses anti-tumor immunity. Together this increases the risk of tumor metastasis, accelerated growth of pre-existing micro-metastasis and cancer recurrence. It was theorized that regional anesthesia could influence long-term outcomes after cancer surgery, however new clinical evidence demonstrates that the anesthesia technique has little influence in oncologic outcomes. Several randomized controlled trials are in progress and may provide a better understanding on how volatile and intravenous hypnotics impact cancer progression. The purpose of this review is to summarize the effect of the anesthesia techniques on the immune system and tumor microenvironment (TME) as well as to summarize the clinical evidence of anesthesia techniques on cancer outcomes.

Predictive Value of Preoperative Profiling of Serum Metabolites for Emergence Agitation After General Anesthesia in Adult Patients

Background: Emergence agitation (EA) in adult patients under general anesthesia leads to increased postoperative complications and heavy medical burden. Unfortunately, its pathogenesis has not been clarified until now. The purpose of the present study was to explore the relationship between preoperative serum metabolites and EA. Methods: We used an untargeted metabolic analysis method to investigate the different metabolomes in the serum of EA patients and non-EA patients undergoing elective surgical procedures after the induction of general anesthesia. A Richmond Agitation-Sedation Scale score ≥ +2 was diagnosed as EA during postoperative emergence. Non-EA patients were matched with EA patients according to general characteristics. Preoperative serum samples of the two groups were collected to investigate the association between serum metabolites and EA development. Results: The serum samples of 16 EA patients with 34 matched non-EA patients were obtained for metabolic analysis. After screening and alignment with databases, 31 altered metabolites were detected between the two groups. These metabolites were mainly involved in the metabolism of lipids, purines, and amino acids. Analyses of receiver-operating characteristic curves showed that the preoperative alterations of choline, cytidine, glycerophosphocholine, L-phenylalanine, oleamide, and inosine may be associated with adult EA. Conclusion: Multiple metabolic abnormalities (including those for lipids, purines, and amino acids) and other pathological processes (e.g., neurotransmitter imbalance and oxidative stress) may contribute to EA. Several altered metabolites in serum before surgery may have predictive value for EA diagnosis. This study might afford new metabolic clues for the understanding of EA pathogenesis.

Assessment of Myocardial Function During Blood Pressure Manipulations Using Feature Tracking Cardiovascular Magnetic Resonance

Background: Coronary autoregulation is a feedback system, which maintains near-constant myocardial blood flow over a range of mean arterial pressure (MAP). Yet in emergency or peri-operative situations, hypotensive or hypertensive episodes may quickly arise. It is not yet established how rapid blood pressure changes outside of the autoregulation zone (ARZ) impact left (LV) and right ventricular (RV) function. Using cardiovascular magnetic resonance (CMR) imaging, measurements of myocardial tissue oxygenation and ventricular systolic and diastolic function can comprehensively assess the heart throughout a range of changing blood pressures.

Design and methods: In 10 anesthetized swine, MAP was varied in steps of 10–15 mmHg from 29 to 196 mmHg using phenylephrine and urapidil inside a 3-Tesla MRI scanner. At each MAP level, oxygenation-sensitive (OS) cine images along with arterial and coronary sinus blood gas samples were obtained and blood flow was measured from a surgically implanted flow probe on the left anterior descending coronary artery. Using CMR feature tracking-software, LV and RV circumferential systolic and diastolic strain parameters were measured from the myocardial oxygenation cines.

Results: LV and RV peak strain are compromised both below the lower limit (LV: Δ1.2 ± 0.4%, RV: Δ4.4 ± 1.2%, p < 0.001) and above the upper limit (LV: Δ2.1 ± 0.4, RV: Δ5.4 ± 1.4, p < 0.001) of the ARZ in comparison to a baseline of 70 mmHg. LV strain demonstrates a non-linear relationship with invasive and non-invasive measures of oxygenation. Specifically for the LV at hypotensive levels below the ARZ, systolic dysfunction is related to myocardial deoxygenation (β = −0.216, p = 0.036) in OS-CMR and both systolic and diastolic dysfunction are linked to reduced coronary blood flow (peak strain: β = −0.028, p = 0.047, early diastolic strain rate: β = 0.026, p = 0.002). These relationships were not observed at hypertensive levels.

Conclusion: In an animal model, biventricular function is compromised outside the coronary autoregulatory zone. Dysfunction at pressures below the lower limit is likely caused by insufficient blood flow and tissue deoxygenation. Conversely, hypertension-induced systolic and diastolic dysfunction points to high afterload as a cause. These findings from an experimental model are translatable to the clinical peri-operative environment in which myocardial deformation may have the potential to guide blood pressure management, in particular at varying individual autoregulation thresholds.

Propofol Requirement and EEG Alpha Band Power During General Anesthesia Provide Complementary Views on Preoperative Cognitive Decline

Background: Although cognitive decline (CD) is associated with increased post-operative morbidity and mortality, routinely screening patients remains difficult. The main objective of this prospective study is to use the EEG response to a Propofol-based general anesthesia (GA) to reveal CD.

Methods: 42 patients with collected EEG and Propofol target concentration infusion (TCI) during GA had a preoperative cognitive assessment using MoCA. We evaluated the performance of three variables to detect CD (MoCA < 25 points): age, Propofol requirement to induce unconsciousness (TCI at SEF₉₅: 8–13 Hz) and the frontal alpha band power (AP at SEF₉₅: 8–13 Hz).

Results: The 17 patients (40%) with CD were significantly older (p < 0.001), had lower TCI (p < 0.001), and AP (p < 0.001). We found using logistic models that TCI and AP were the best set of variables associated with CD (AUC: 0.89) and performed better than age (p < 0.05). Propofol TCI had a greater impact on CD probability compared to AP, although both were complementary in detecting CD.

Conclusion: TCI and AP contribute additively to reveal patient with preoperative cognitive decline. Further research on post-operative cognitive trajectory are necessary to confirm the interest of intra operative variables in addition or as a substitute to cognitive evaluation.

Comparison of the effects of general and local anesthesia in lumbar interlaminar endoscopic surgery

BACKGROUND

Percutaneous endoscopic lumbar discectomy (PELD) with an interlaminar approach is a technique used to treat lumbar disc hernia. It has not yet been established whether general or local anesthesia (LA) is preferable for lumbar interlaminar endoscopic surgery.

METHODS

Between October, 2012 and June, 2016, 60 patients were recruited and randomly divided into 2 groups: the general anesthesia (GA) group and the LA group. The patients' basic clinical data, intraoperative patient experience, Oswestry disability index (ODI), visual analog scale (VAS) score, and the postoperative patient satisfaction rate were assessed.

RESULTS

Statistically significant differences were found between the two groups in operative time and length of hospital stay. There were no significant differences in postoperative ODI or VAS scores between the two groups during follow-up at 3, 6, and 12 months. One patient in the GA group sustained a nerve root injury intraoperatively. Two patients in the LA group suffered adverse reactions, as did six patients in the GA group. However, 50% of the patients expressed fear about undergoing the surgery with LA, while all patients felt they could undergo the same surgery with GA.

CONCLUSIONS

General and LA are both suitable for use in lumbar interlaminar endoscopic surgery. However, GA makes a positive intraoperative surgical experience more likely for the patient.

Comparison between monitored anesthesia care and general anesthesia in patients undergoing device closure of atrial septal defect

Background

Percutaneous atrial septal defect (ASD) device closure is usually performed under general anesthesia (GA) because it can ensure protection of the airway from the effects of insertion of the transesophageal echocardiogram probe insertion. However, recent studies have suggested that this procedure can be performed safely under deep sedation also. Thus, we compared the efficacy of using monitored anesthesia care (MAC) with deep sedation versus GA to perform this procedure and the post-procedural outcomes and incidence of complications associated with these two methods of anesthesia.

Methods

We retrospectively analyzed cases involving 311 patients who underwent ASD device closures from January 2011 to December 2015. The demographics, laboratory values, echocardiographic findings, and intraoperative data of these patients were assessed. GA was induced with a continuous infusion of propofol and remifentanil using a target control infusion pump. MAC with deep sedation was performed by using a continuous infusion of dexmedetomidine and remifentanil. The primary outcome of the study was the overall complication rate that included the incidence of aspiration pneumonia, sore throat, dysphagia, vocal cord palsy, neurologic complication, device-related complications, and other minor complications during the procedure; and the secondary outcomes were the turnover time, procedure time, and duration of hospital stay.

Results

No significant differences were observed in the complication rate and length of the hospital stay between the MAC group and the GA group. However, the turnover time was significantly longer in the GA group than in the MAC group (56.2±13.3 vs. 51.0±15.4 min, P=0.004).

Conclusions

MAC under deep sedation is an effective and safe anesthetic option comparable to GA for performing percutaneous ASD device closures.

Sedation versus general anesthesia for transcatheter aortic valve replacement

There is currently significant controversy regarding the best anesthesia management for patients undergoing transcatheter aortic valve replacement (TAVR). Some institutions primarily use general anesthesia (GA) but many institutions primarily use moderate sedation. Much of the controversy is due to the limited evidence base available to inform this decision and the strong feelings and pre-conceived notions about the optimal anesthesia technique which exist amongst anesthesiologists, cardiologists, and cardiac surgeons. In this article and in the context of TAVR, we will define the salient differences between GA and sedation, review the results and limitations of the currently available data, and discuss the priority questions for future research.

Nonintubated anesthesia in thoracic surgery: general issues

Anesthetic management for awake thoracic surgery (ATS) is more difficult than under general anesthesia (GA), being technically extremely challenging for the anesthesiologist. Therefore, thorough preparation and vigilance are paramount for successful patient management. In this review, important considerations of nonintubated anesthesia for thoracic surgery are discussed in view of careful patient selection, anesthetic preparation, potential perioperative difficulties and the management of its complications.