Comparison of the effect of sevoflurane or propofol anesthesia on the regional cerebral oxygen saturation in patients undergoing carotid endarterectomy: a prospective, randomized controlled study

The diagnostic accuracy of intraoperative near-infrared spectroscopy in carotid artery endarterectomy under general anesthesia: A systematic review with meta-analysis

BACKGROUND

Carotid endarterectomy (CEA) carries a risk of perioperative stroke, particularly during carotid cross-clamping. While neurological monitoring is reliable for patients under regional anesthesia, alternative options are needed for those unsuitable for regional anesthesia. Near-infrared spectroscopy (NIRS) is commonly used during CEA, but its diagnostic accuracy varies, particularly under general anesthesia.

METHODS

A systematic review with meta-analysis was performed to assess the diagnostic accuracy of intraoperative NIRS in detecting clamp-associated hemodynamic cerebral ischemia in patients under general anesthesia. MEDLINE, Google Scholar, and Web of Science were searched for studies that compared NIRS with the occurrence of immediate or early postoperative neurological deficits in patients undergoing CEA under GA. Meta-regression was performed to explore causes of heterogeneity.

RESULTS

A total of 28 studies involving 5729 patients were included. The results show that NIRS has a summary sensitivity of 47.5% and a summary specificity of 90.3% in diagnosing clamp-associated cerebral ischemia under general anesthesia, with an area under the ROC curve (AUC-ROC) of 0.85. The presence of a contralateral carotid occlusion (CCO) increased summary sensitivity while smoking history the presence of CCO and smoking history decreased summary specificity. For postoperative stroke prediction, NIRS has a summary sensitivity of 49.5% and summary specificity of 88.5%, with an AUC-ROC of 0.85.

CONCLUSIONS

NIRS is a specific but not highly sensitive tool for detecting cerebral ischemia during CEA, and its use in combination with more sensitive neuromonitoring methods is recommended, in order to guide intraoperative neuroprotective strategies.

Effects of anesthesia on cerebral oxygen saturation and prevention of brain injury during carotid endarterectomy

BACKGROUND

This study aimed to investigate the effects of general intravenous anesthesia and combined inhalation anesthesia on regional saturation of oxygen (rSO2) and cerebral hemodynamics during carotid endarterectomy (CEA). Optimizing intraoperative brain protection strategies has become a key focus in CEA research.

METHODS

Fifty-four patients (43 males, 11 females, aged 44-80) undergoing unilateral CEA were randomly assigned to Group IVA (intravenous anesthesia) or Group CIA (combined inhalation anesthesia), with 27 patients each. Group IVA was maintained with propofol and remifentanil, while Group CIA used sevoflurane, propofol, and remifentanil, with sevoflurane stopped after carotid exposure. Hemodynamics were controlled at various stages: ±10% before clamping, + 20% during clamping (metaraminol), and 0 to -10% after exposure. HR, MAP, and rSO₂ were recorded at T0 (pre-induction), T1 (pre-clamping), T2 (post-clamping), T3 (5 min post-clamping), T4 (10 min post-clamping), T5 (15 min post-clamping), and T6 (15 min post-reperfusion). Blood samples were taken at T1, T6, and T7 (24 h post-surgery) for blood gas and S100-β analysis.

RESULTS

No significant differences in rSO₂ were observed at T0 and T6 (P > 0.05). However, Group CIA had significantly higher rScO₂ at T1, T2, T3, T4, and T5 (P < 0.05). From T2 to T5, rSO₂ increased in both groups (P < 0.05). MAP and HR showed no significant differences (P > 0.05). ΔrSO₂ increased more in Group CIA (P < 0.05). At T6, S100-β protein was higher in Group IVA (P = 0.016), and pH differed significantly at T1 (P = 0.009). No other significant differences were observed.

CONCLUSION

Both intravenous and combined inhalation anesthesia may reduce rSO₂ decline during temporary clamping in CEA. Combined inhalation anesthesia showed a trend toward higher rSO₂ levels, potentially leading to better outcomes, but further studies are needed to confirm these findings.

RETROSPECTIVELY REGISTERED CLINICAL TRIAL NUMBER

ISRCTN17014575; Registration Date: 2024/6/10.

Impact of Manual Sustained Inflation vs Stepwise PEEP on Pulmonary and Cerebral Outcomes in Carotid Endarterectomy Patients

BACKGROUND Recruitment maneuvers (RMs) are used to reduce pulmonary atelectasis in patients under general anesthesia, but they can lead to a decrease in cerebral hemodynamics. MATERIAL AND METHODS Thirty patients undergoing carotid endarterectomy were randomized to a manual sustained inflation (SI) group or a stepwise increase in PEEP (IP) group. During both RMs, the peak airway pressure (Ppeak) was maintained at 30 cmH₂O for 30 s. Electrical impedance tomography was used to evaluate pulmonary aeration changes. Mean velocity of blood flow in the middle cerebral artery (Vm) and cerebral oxygen saturation (rScO₂) was monitored intraoperatively. RESULTS IP improved lung aeration better at Ppeak=30 cmH₂O than SI (58.2±8.4% vs 46.0±8.3%, P=0.001) and this persisted until the end of surgery. Dorsal (dependent) ventilation 30 min after extubation in the SI group was lower than that before surgery (7.7±2.6% vs 9.9±3.8%, P=0.003). Vm and rScO₂ returned to baseline immediately after RM in the SI group, while it remained below baseline in the IP group (42.5±12.6 vs 50.9±18.8 cm/s, P<0.001 and 68.1±3.5% vs 70.6±3.7%, P=0.001). Heart rate declined significantly during RM only in the SI group (55.9±6.6 vs 52.2±6.9 bpm, P=0.008). CONCLUSIONS Compared with SI, IP performed better in improving lung aeration, with greater hemodynamic stability. IP resulted in slower recovery of cerebral blood flow and oxygenation.

Appraisal of Postoperative Outcomes of Volatile and Intravenous Anesthetics: A Network Meta-Analysis of Patients Undergoing Cardiac Surgery

OBJECTIVES

To determine the relative efficacy of specific regimens used as primary anesthetics, as well as the potential combination of volatile and intravenous anesthetics among patients undergoing cardiac, thoracic, and vascular surgery.

DESIGN

This frequentist, random-effects network meta-analysis was registered prospectively (CRD42022316328) and conducted according to the PRISMA-NMA framework. Literature searches were conducted up to April 1, 2022 across relevant databases. Risk of bias (RoB) and confidence of evidence were assessed by RoB-2 and CINeMA, respectively. Pooled treatment effects were compared with propofol monotherapy.

SETTING

Fifty-three randomized controlled trials (N = 8,085) were included, of which 46 trials (N = 6,604) enrolled patients undergoing cardiac surgery.

PARTICIPANTS

Trials enrolling adults (≥18) undergoing cardiac, thoracic, and vascular surgery, using the same induction regimens, and comparing volatile and/or total intravenous anesthesia for the maintenance of anesthesia. Given that the majority of trials focused on those undergoing cardiac surgery and the heterogeneity, analyses were restricted to this population.

MEASUREMENT AND MAIN RESULTS

Outcomes of interest included intensive care unit (ICU) length of stay (LOS), myocardial infarction, in-hospital and 30-day mortality, stroke, and delirium. Across 19 trials (N = 1,821; 9 arms; I2 = 64.5%), sevoflurane combined with propofol decreased ICU LOS (mean difference [MD] -18.26 hours; 95% CI -34.78 to -1.73 hours), whereas midazolam with propofol (MD 17.51 hours; 95% CI 2.78-32.25 hours) was associated with a significant increase in ICU LOS, when compared with propofol monotherapy. Among 27 trials (N = 4,080; 10 arms; I2 = 0%), midazolam was associated with significantly greater risk of myocardial infarction versus propofol (risk ratio 1.94; 95% CI 1.01-3.71). There were no significant differences across other outcomes.

CONCLUSION

In patients undergoing cardiac surgery, sevoflurane with propofol was associated with decreased ICU LOS compared with propofol monotherapy. Midazolam with propofol increased ICU LOS compared with propofol alone. The combined use of intravenous and volatile anesthetics should be explored further. Future trials in thoracic and vascular surgery are warranted.

Effect of remimazolam versus propofol for the induction of general anesthesia on cerebral blood flow and oxygen saturation in elderly patients undergoing carotid endarterectomy

BACKGROUND

This study was conducted to investigate the effects and safety of remimazolam versus propofol on cerebral oxygen saturation and cerebral hemodynamics during the induction of general anesthesia in patients receiving carotid endarterectomy (CEA), so as to provide theoretical basis for better clinical application of remimazolam.

METHODS

Forty-three patients (60-75 years old) with carotid artery stenosis (carotid artery stenosis greater than 70%) were randomly divided into the remimazolam group (R group) and the propofol group (P group). Anesthesia was induced with remimazolam (0.3 mg/kg) or propofol (1.5-2 mg/kg) individually. At time of admission (T0), post-anesthesia induction (T1), consciousness disappears (T2), 1 min after loss of consciousness (T3), 2 min after loss of consciousness (T4) and pre-endotracheal intubation (T5), measurement in patients with regional cerebral oxygen saturation (SrO₂), average blood flow velocity (Vm), resistance index (RI), mean arterial pressure (MAP), heart rate (HR) and cardiac index (CI) were recorded.

RESULTS

SrO₂ increased significantly in both groups after induction of anesthesia compared with baseline (P < 0.05) and decreased after loss of consciousness (P < 0.05). There was no difference in the mean value of the relative changes in SrO₂ between the groups. Meanwhile, the Vm, RI, HR and CI of each time point between two groups showed no statistically significant difference (P > 0.05) while MAP in group P at T5 was lower than that in group R individually(P < 0.05). In each group, Vm, HR, CI and MAP at T2-T5 were all significantly reduced compared with T1, with statistically differences(P < 0.05). Specifically, there was no difference of RI at each time between or within groups(P > 0.05).

CONCLUSIONS

Our study revealed that remimazolam can be administered safely and effectively during the induction of general anesthesia for carotid endarterectomy in elder population and it demonstrated superiority in hemodynamic changes compared with propofol.

CLINICAL TRIAL REGISTRATION

This trial was retrospectively registered with the Chinese Clinical Trial Registry.

REGISTRATION NUMBER

ChiCTR2300070370. Date of registration: April 11, 2023.

Comparison of cerebral metabolic rate of oxygen, blood flow, and bispectral index under general anesthesia

Significance

The optical measurement of cerebral oxygen metabolism was evaluated.

Aim

Compare optically derived cerebral signals to the electroencephalographic bispectral index (BIS) sensors to monitor propofol-induced anesthesia during surgery.

Approach

Relative cerebral metabolic rate of oxygen (rCMRO 2 ) and blood flow (rCBF) were measured by time-resolved and diffuse correlation spectroscopies. Changes were tested against the relative BIS (rBIS) ones. The synchronism in the changes was also assessed by the R-Pearson correlation.

Results

In 23 measurements, optically derived signals showed significant changes in agreement with rBIS: during propofol induction, rBIS decreased by 67% [interquartile ranges (IQR) 62% to 71%],rCMRO 2 by 33% (IQR 18% to 46%), and rCBF by 28% (IQR 10% to 37%). During recovery, a significant increase was observed for rBIS (48%, IQR 38% to 55%),rCMRO 2 (29%, IQR 17% to 39%), and rCBF (30%, IQR 10% to 44%). The significance and direction of the changes subject-by-subject were tested: the coupling between the rBIS,rCMRO 2 , and rCBF was witnessed in the majority of the cases (14/18 and 12/18 for rCBF and 19/21 and 13/18 forrCMRO 2 in the initial and final part, respectively). These changes were also correlated in time ( R > 0.69 to R = 1 , p - values < 0.05 ).

Conclusions

Optics can reliably monitorrCMRO 2 in such conditions.

Effect of remifentanil combined with sevoflurane inhalation anesthesia on coagulation function and postoperative recovery of patients undergoing endoscopic selective varices devascularization

OBJECTIVE

To investigate the effect of remifentanil combined with sevoflurane inhalation anesthesia on coagulation function and postoperative recovery of patients undergoing endoscopic selective varices devascularization (ESVD).

METHODS

Altogether 116 patients undergoing ESVD in our hospital were randomly divided into two groups. The control group received propofol combined with remifentanil anesthesia, while the observation group received remifentanil combined with sevoflurane inhalation anesthesia.

RESULTS

There was no statistical difference in coagulation function indexes between the control group and the observation group (P>0.05), and the clinical anesthesia effect of the observation group was better (P<0.001). Five minutes after intubation, compared with the control group, the clinical stress response index was better (all P<0.001), the quality of anesthesia recovery was higher (all P<0.001), the heart rate was better after anesthesia (P<0.001), and the incidence of adverse reactions was higher (P<0.01) in the observation group.

CONCLUSION

Compared with remifentanil combined with propofol anesthesia, remifentanil combined with sevoflurane inhalation anesthesia for ESVD can effectively improve the clinical anesthesia effect, improve the quality of anesthesia recovery, and reduce stress reactions, but the incidence of adverse reactions is increased. Therefore the clinical application still needs to be strengthened.

Postoperative recovery of patients with differential requirements for sevoflurane after abdominal surgery: A prospective observational clinical study

An association between animals and volatile anaesthetic requirements has been shown; however, evidence related to the postoperative outcome of human patients is lacking. Our aim was to investigate whether there is a difference in the requirement for sevoflurane among people undergoing gastrointestinal surgery.We observed 390 adult patients who underwent gastrointestinal surgery with an American Society of Anesthesiologists physical status of I or II with an expected surgery duration of > 2 hours. We used the bispectral index (BIS) to guide the regulation of end-tidal sevoflurane concentration (ETsevo). The mean ETsevo from 20 minutes after endotracheal intubation to 2 hours after the start of surgery was calculated for all patients. Differential sevoflurane requirements were identified according to ETsevo. The BIS, ETsevo, heart rate, mean arterial pressure, dose of sufentanil and cisatracurium, tracheal extubation time, incidence of intraoperative awareness, and incidence of postoperative nausea and vomiting were compared between patients with a low requirement for sevoflurane (group L) and patients with a high requirement for sevoflurane (group H).The mean ETsevo of the 390 patients was 1.55% ± 0.26%. Based on our definition, patients with an ETsevo of < 1.29% were allocated to the low requirement group (group L; n = 69), while patients with an ETsevo of > 1.81% were allocated to the high requirement group (group H; n = 78). The ETsevo of group L was significantly lower than the ETsevo of group H (1.29% ± 0.014% vs 1.82% ± 0.017%, P < .001). There was no significant difference in the ETsevo, BIS, heart rate, mean arterial pressure, dose of sufentanil and cisatracurium, tracheal extubation time, incidence of intraoperative awareness, and incidence of postoperative nausea and vomiting. The tracheal extubation time in the L group was significantly shorter than that in the H group. No intraoperative awareness occurred.There was a significant difference in the requirement for sevoflurane in adult patients. The tracheal extubation time in group L was significantly shorter than that in group H.

Effects of end-tidal carbon dioxide levels in patients undergoing direct revascularization for Moyamoya disease and risk factors associated with postoperative complications

A history of transient ischemic attack, severity of disease, urinary output, hematocrit, hypocapnia, and hypotension during direct revascularization (superficial temporal artery to middle cerebral artery [STA-MCA]) in patients with Moyamoya disease (MMD) may lead to a poor prognosis, however, to our knowledge evidence for end-tidal carbon dioxide (ETCO2) targets is lacking. Within the ranges of standardized treatment, the article was primarily designed to study the risk factors associated with the neurologic outcomes during STA-MCA for MMD especially including ETCO2 ranges and the duration in different groups. The primary goals of this study were to investigate the risk factors for neurologic deterioration and explore the association between ETCO2 ranges and neurologic outcome during general anesthesia for STA-MCA.This retrospective observational study included 56 consecutively adult Moyamoya patients who underwent STA-MCA under general anesthesia between January 2015 and August 2019. ETCO2 was summarized per patient every 5 minutes. Clinical outcome was assessed with clinical presentation, computed tomography findings, magnetic resonance imaging findings, cerebral angiography, and the modified Rankin Scale scores at discharge as main outcome measure. The outcomes were also compared for the duration of surgery, anesthesia, and the length of stay.A total of 56 patients were studied, all patients had comprehensive ETCO2 measurements. The incidence of postoperative complications was 44.6% (25/56). There was no association between age, sex, hypertension, diabetes, smoking history, drinking history, sevoflurane use, invasive arterial blood pressure monitoring, combined encephalomyosynangiosis and postoperative complications. Duration of surgery (P = .04), anesthesia (P = .036), hospital stay (P = .023) were significant correlates of postoperative complications. In the multiple logistic regression model, they were not the significant predictors. The ETCO2 ranges and the length of time in different groups within the current clinical setting was not associated with postoperative complications (P > .05).Within a standardized intraoperative treatment strategy, we found that postoperative complications had no significant correlation with sex, age, hypertension, diabetes, smoking history, drinking history, invasive arterial blood pressure monitoring, combined encephalomyosynangiosis, or sevoflurane use. Further, hypocapnia and hypercapnia during STA-MCA were not found to be associated with postoperative complications in patients with MMD.