Search Results (9)

Background: Preoperative clear fluid fasting is intended to reduce aspiration risk, but prolonged abstinence may impair hydration, comfort, and cardiovascular stability. Arterial hypotension during anesthesia induction is a common perioperative complication, and its association with fasting duration has become an important concern. The objective of this review was to evaluate the relationship between the duration of preoperative clear fluid fasting and the risk of arterial hypotension during anesthesia induction in both adult and pediatric populations. Methods: A structured PubMed search identified 17 studies, including randomized controlled trials, prospective cohorts, registry-based analyses, and interventional imaging investigations. Data were extracted on patient age, fasting duration, hypotension definitions, and monitoring modalities. Subgroups included adults, pediatric patients, and studies employing echocardiography or ultrasound to evaluate preload. Results: A total of 96,017 patients were included (77,978 adults; 17,685 children). In adults, fasting beyond two hours was associated with hypovolemia and a greater incidence of post-induction hypotension, while fasting of ≤2 h improved hemodynamic stability without increasing aspiration risk. Pediatric studies demonstrated fasting durations often exceeding 6–10 h, correlating with higher odds of hypotension and metabolic derangements. Liberalized regimens, including carbohydrate-containing fluids, were consistently safe. Ultrasound-based studies revealed increased inferior vena cava collapsibility and reduced ventricular filling after prolonged fasting, providing a mechanistic explanation for blood pressure instability. Conclusions: Prolonged preoperative fasting was not consistently an independent predictor of peri-induction hypotension in all populations; however, data from large adult and pediatric studies demonstrate that extended fasting increases hypotension risk through volume and metabolic depletion. These findings support the importance of liberalized fasting policies and proactive fluid optimization to reduce early hemodynamic instability during anesthesia induction. Full article

Background: Remifentanil, an ultra-short-acting μ-receptor agonist, is used with propofol or thiopental for tracheal intubation without muscle relaxants. While effective with both, its combination with thiopental provides better hemodynamic stability. Thiopental has long been a standard intravenous agent for anaesthesia induction and remains a cost-effective alternative to propofol in resource-limited settings. To date, no study has directly compared the effects of thiopental–remifentanil and propofol–remifentanil combinations on LMA insertion conditions. This study aims to compare the effects of thiopental or propofol with 2 µg·kg⁻¹ remifentanil on laryngeal mask airway (LMA) insertion conditions and success in a prospective, randomised double-blind study. Method: The study included 80 premedicated ASA I-II patients, aged 18–65, randomised into Group P (propofol) and Group T (thiopental). Anaesthesia induction was with 2 μg·kg⁻¹ remifentanil, followed by 5 mg·kg⁻¹ thiopental or 2.5 mg·kg⁻¹ propofol. LMA insertion occurred 90 s post-induction. LMA insertion conditions were evaluated using a six-variable scale. Systolic arterial pressure (SAP), diastolic arterial pressure (DAP), mean arterial pressure (MAP), heart rate (HR), and bispectral index monitor (BIS) values were recorded at baseline, 1 min pre-insertion, and at 1, 2, 3, 4, and 5 min after insertion. Apnoea duration, loss of eyelash reflex duration, insertion duration, number of attempts, and perioperative complications were also documented. Results: Demographic data were similar. Group P showed significantly shorter eyelash reflex loss and LMA insertion durations, longer apnoea duration, and higher rates of full mouth opening, excellent LMA insertion condition, and hypotension or bradycardia compared to Group T (p < 0.05). Group P had significantly lower HR, SAP, DAP, and MAP at various time points (p < 0.05). There were no significant differences in blood presence on LMA, sore throat, or dysphagia (p > 0.05). Conclusions: In our study, administration of 2 μg·kg⁻¹ remifentanil before induction along with thiopental or propofol was shown to provide acceptable LMA insertion conditions at comparable levels. As hemodynamic parameters were less affected, we believe the remifentanil–thiopental combination may be a suitable alternative. Full article

Objectives: Laparoscopic gynecological surgeries are commonly performed under general anesthesia and can induce cardiovascular depression and hypotension, requiring vasopressor support. Remimazolam, a novel ultra-short-acting benzodiazepine, is used to treat minimal cardiovascular depression. This study compared the hemodynamic effects of remimazolam and sevoflurane anesthesia in patients undergoing laparoscopic gynecological surgery. Methods: A retrospective analysis was conducted on 474 patients who underwent laparoscopic gynecological surgery at Korea University Anam Hospital between September 2021 and December 2022. The patients were categorized into two groups based on the anesthetic agent used: remimazolam or sevoflurane. Hemodynamic parameters, vasopressor use, and intraoperative variables were compared between anesthetic agents. Propensity score matching was applied to account for potential confounders, and logistic regression was utilized to assess the relationship between anesthesia type and outcomes. Results: Remimazolam anesthesia was linked to a significantly lower incidence of vasopressor use compared to sevoflurane-based anesthesia (3.7% vs. 19.5%, p < 0.0001). The odds of requiring vasopressor support were significantly lower during the post-induction and maintenance phases in the remimazolam group. Furthermore, hemodynamic stability, particularly systolic and mean arterial pressures, was better maintained with remimazolam than sevoflurane. Conclusions: Remimazolam provides superior hemodynamic stability and reduces the need for vasopressor support during laparoscopic gynecological surgery compared with sevoflurane. Full article

Post-induction hypotension (PIH) is a common and potentially serious complication of general anesthesia. This meta-analysis (Prospero registration number: CRD42024566321) aimed to evaluate the predictive efficacy of the perfusion index (PI) for PIH in patients undergoing general anesthesia. A comprehensive literature search was performed using multiple electronic databases (Google Scholar, EMBASE, Cochrane Library, and MEDLINE). Studies involving adult patients undergoing general anesthesia, with the PI measured before anesthesia induction and reporting PIH incidence, were included. The primary outcome was the diagnostic accuracy of the PI in predicting the probability of PIH. The secondary outcome was the pooled PIH incidence. Eight studies with 678 patients were included. The pooled incidence of PIH was 44.8% (95% confidence interval [CI]: 29.9%–60.8%). The combined sensitivity and specificity of the PI for predicting PIH were 0.84 (95% CI: 0.65–0.94) and 0.82 (95% CI: 0.70–0.90), respectively. The summary receiver operating characteristic (sROC) analysis revealed an area under curve of 0.89 (95% CI: 0.86–0.92). The Deek’s funnel plot asymmetry test indicated no significant publication bias. The PI demonstrates high predictive efficacy for PIH in patients undergoing general anesthesia, indicating that it can be a valuable tool for identifying those at risk of PIH. Full article

Postinduction hypotension (PIH) is closely associated with postoperative adverse outcomes. Preoperative hypovolemia is a key risk factor, and many parameters are available from ultrasound to detect hypovolemia, but the accuracy of PIH from ultrasound remains unclear. This systematic review and meta-analysis aimed to evaluate the commonly used measurements from ultrasound to predict PIH. We searched the PubMed, Cochrane Library, Embase, CNKI, and Web of Science databases from their inception to December 2023. Thirty-six studies were included for quantitative analysis. The pooled sensitivities for the inferior vena cava collapsibility index (IVC-CI), maximum inferior vena cava diameter (DIVCmax), minimum inferior vena cava diameter (DIVCmin), and carotid artery corrected flow time (FTc) were 0.73 (95% CI = 0.65, 0.79), 0.66 (95% CI = 0.54, 0.77), 0.74 (95% CI = 0.60, 0.85), and 0.81 (95% CI = 0.72, 0.88). The pooled specificities for the IVC-CI, DIVCmax, DIVCmin, and carotid artery FTc were 0.82 (95% CI = 0.75, 0.87), 0.75 (95% CI = 0.66, 0.82), 0.76 (95% CI = 0.65, 0.84), and 0.87 (95% CI = 0.77, 0.93). The AUC for the IVC-CI, DIVCmax, DIVCmin, and carotid artery FTc were 0.84 (95% CI = 0.81, 0.87), 0.77 (95% CI = 0.73, 0.81), 0.82 (95% CI = 0.78, 0.85), and 0.91 (95% CI = 0.88, 0.93). Our study demonstrated that ultrasound indices are reliable predictors for PIH. The carotid artery FTc is probably the optimal ultrasound measurement for identifying patients who will develop PIH in our study. Full article

Background: Post-induction hypotension frequently occurs and can lead to adverse outcomes. As target-controlled infusion (TCI) obviates the need to calculate the infusion rate manually and helps safer dosing with prompt titration of the drug using complex pharmacokinetic models, the use of TCI may provide a better hemodynamic profile during anesthesia induction. This study aimed to compare TCI versus manual induction and to determine the hemodynamic risk factors for post-induction hypotension. Methods: A total of 200 ASA grade 1–3 patients, aged 24 to 82 years, were recruited and randomly assigned to the TCI (n = 100) or manual induction groups (n = 100). Hemodynamic parameters were monitored with the pressure-recording analytic method. The propofol dosage was adjusted to keep the Bispectral Index between 40 and 60. Results: Post-induction hypotension was significantly higher in the manual induction group than in the TCI group (34% vs. 13%; p < 0.001, respectively). The propofol induction dose did not differ between the groups (TCI: 155 (135–180) mg; manual: 150 (120–200) mg; p = 0.719), but the induction time was significantly longer in the TCI group (47 (35–60) s vs. 150 (105–220) s; p < 0.001, respectively). In the multivariable Cox regression model, the presence of hypertension, stroke volume index (SVI), cardiac power output (CPO), and anesthesia induction method were found to predict post-induction hypotension (p = 0.032, p = 0.013, p = 0.024, and p = 0.015, respectively). Conclusion: TCI induction with propofol provided better hemodynamic stability than manual induction, and the presence of hypertension, a decrease in the pre-induction SVI, and the CPO could predict post-induction hypotension. Full article

Background: Hypotension is common after anesthesia induction and may have adverse outcomes. The aim of this study was to investigate whether arterial elastance (Ea) is a predictor of post-induction hypotension. Methods: Between January and June 2022, the hemodynamic parameters of 85 patients who underwent major surgery under general anesthesia were prospectively evaluated. The noncalibrated pulse contour device MostCare (Vytech, Vygon, Padua, Italy) was used to measure hemodynamic parameters before and after anesthesia induction. The duration of the measurements was determined from one minute before induction to 10 min after induction. Hypotension was defined as a greater than 30% decrease in mean arterial pressure from the pre-induction value and/or systolic arterial pressure of less than 90 mmHg. The patients were divided into post-induction hypotension (−) and (+) groups. For the likelihood of post-induction hypotension, a multivariate regression model was used by adding significantly different pre-induction parameters to the post-induction hypotension group. Results: The incidence of post-induction hypotension was 37.6%. The cut-off value of the pre-induction Ea for the prediction of post-induction hypotension was ≥1.08 mmHg m⁻²mL⁻¹ (0.71 [0.59–0.82]). In the multivariate regression model, the likelihood of postinduction hypotension was 3.5-fold (1.4–9.1), increased by only an Ea ≥ 1.08 mmHg m⁻²mL⁻¹. Conclusion: Pre-induction Ea showed excellent predictability of hypotension during anesthetic induction and identified patients at risk of general anesthesia induction-related hypotension. Full article

Patients with hypertension develop hemodynamic instability more frequently during anesthesia—particularly post-induction. Therefore, different monitoring methods may be required in patients with hypertension. Perfusion index—the ratio of the pulsatile blood flow to the non-pulsatile static blood flow in a patient’s peripheral tissues, such as the fingers or ears—can show the hemodynamic status of the patient in a non-invasive way. Among the sites used for measuring the perfusion index, it is assumed that the ear is more reliable than the finger for hemodynamic monitoring, because proximity to the brain ensures appropriate perfusion. We hypothesized that the low value of preoperative ear PI could be a predictor of post-induction hypotension in patients with hypertension. Thirty patients with hypertension were enrolled. The perfusion index and pleth variability index were measured using the ear, finger, and blood pressure, and heart rate was recorded to monitor hypotension. After insertion of the supraglottic airway, 20 patients developed post-induction hypotension. Those who developed hypotension showed a significantly lower preoperative perfusion index of the ear. The preoperative perfusion index of the ear could predict post-induction hypotension in patients with hypertension. Full article

Hypotensive events in the initial stage of anesthesia can cause serious complications in the patients after surgery, which could be fatal. In this study, we intended to predict hypotension after tracheal intubation using machine learning and deep learning techniques after intubation one minute in advance. Meta learning models, such as random forest, extreme gradient boosting (Xgboost), and deep learning models, especially the convolutional neural network (CNN) model and the deep neural network (DNN), were trained to predict hypotension occurring between tracheal intubation and incision, using data from four minutes to one minute before tracheal intubation. Vital records and electronic health records (EHR) for 282 of 319 patients who underwent laparoscopic cholecystectomy from October 2018 to July 2019 were collected. Among the 282 patients, 151 developed post-induction hypotension. Our experiments had two scenarios: using raw vital records and feature engineering on vital records. The experiments on raw data showed that CNN had the best accuracy of 72.63%, followed by random forest (70.32%) and Xgboost (64.6%). The experiments on feature engineering showed that random forest combined with feature selection had the best accuracy of 74.89%, while CNN had a lower accuracy of 68.95% than that of the experiment on raw data. Our study is an extension of previous studies to detect hypotension before intubation with a one-minute advance. To improve accuracy, we built a model using state-of-art algorithms. We found that CNN had a good performance, but that random forest had a better performance when combined with feature selection. In addition, we found that the examination period (data period) is also important. Full article