Hemodynamic changes in the prone position according to fluid loading after anaesthesia induction in patients undergoing lumbar spine surgery: a randomized, assessor-blind, prospective study.

INTRODUCTION: A change from the supine to prone position causes hemodynamic alterations. We aimed to evaluate the effect of fluid preloading in the supine position, the subsequent hemodynamic changes in the prone position and postoperative outcomes. PATIENTS AND METHODS: This prospective, assessor-blind, randomized controlled trial was conducted between March and June 2023. Adults scheduled for elective orthopaedic lumbar surgery under general anaesthesia were enrolled. In total, 80 participants were randomly assigned to fluid maintenance (M) or loading (L) groups. Both groups were administered intravenous fluid at a rate of 2 ml/kg/h until surgical incision; Group L was loaded with an additional 5 ml/kg intravenous fluid for 10 min after anaesthesia induction. The primary outcome was incidence of hypotension before surgical incision. Secondary outcomes included differences in the mean blood pressure (mBP), heart rate, pleth variability index (PVi), stroke volume variation (SVV), pulse pressure variation (PPV), stroke volume index and cardiac index before surgical incision between the two groups. Additionally, postoperative complications until postoperative day 2 and postoperative hospital length of stay were investigated. RESULTS: Hypotension was prevalent in Group M before surgical incision and could be predicted by a baseline PVi >16. The mBP was significantly higher in Group L immediately after fluid loading. The PVi, SVV and PPV were lower in Group L after fluid loading, with continued differences at 2-3 time points for SVV and PPV. Other outcomes did not differ between the two groups. CONCLUSION: Fluid loading after inducing general anaesthesia could reduce the occurrence of hypotension until surgical incision in patients scheduled for surgery in the prone position. Additionally, hypotension could be predicted in patients with a baseline PVi >16. Therefore, intravenous fluid loading is strongly recommended in patients with high baseline PVi to prevent hypotension after anaesthesia induction and in the prone position. TRIAL NUMBER: KCT0008294 (date of registration: 16 March 2023).

Fluid preloading could reduce the occurrence of hypotension in the prone position. Hypotension could be predicted in patients with a baseline PVi >16. Intravenous fluid preloading is strongly recommended in patients with high baseline PVi to prevent hypotension after anaesthesia induction and in the prone position.

Comparison of Hemodynamic Parameters Based on the Administration of Remimazolam or Sevoflurane in Patients under General Anesthesia in the Beach Chair Position: A Single-Blinded Randomized Controlled Trial.

Background: We aimed to evaluate whether the administration of remimazolam as a maintenance agent for general anesthesia affects the occurrence of hypotension compared with sevoflurane when switching to the beach chair position (BCP). Methods: We conducted a prospective randomized controlled trial from June 2023 to October 2023 in adult patients undergoing orthopedic surgery under general anesthesia in the BCP. A total of 78 participants were randomly allocated to the remimazolam (R) or sevoflurane (S) groups. The primary outcome was the incidence of hypotension that occurred immediately after switching to a BCP. The secondary outcomes included differences between the study groups in perioperative blood pressure (BP), heart rate (HR), endotracheal tube extubation time, postoperative complications, and hospital length of stay (LOS). Results: The incidence of hypotension immediately after switching to a BCP was significantly higher in the S group. The risk factors associated with hypotension included sevoflurane administration and a high baseline systolic BP. In the receiver operating characteristic curve analysis for the occurrence of hypotension after the transition to a BCP, the cutoff value for systolic BP was 142 mmHg. The perioperative BP and HR were higher in the R group at several timepoints. Postoperative endotracheal tube extubation time was shorter in the R group. There were no significant differences in the postoperative complications or hospital LOS between the two groups. Conclusions: Remimazolam should be considered as an anesthetic agent to prevent hypotension when switching to BCP, and hypotension may occur frequently in patients with high baseline BP.

Comparison of oxygen reserve index according to the remimazolam or dexmedetomidine for intraoperative sedation under regional anesthesia-A single-blind randomized controlled trial.

Introduction: We aimed to evaluate the difference in intraoperative oxygen reserve index (ORi) between the sedatives remimazolam (RMMZ) and dexmedetomidine (DEX). Methods: Seventy-eight adult patients scheduled for sedation under regional anesthesia were randomly assigned to either the DEX (n = 39) or RMMZ (n = 39) group. The primary outcome was the difference in perioperative ORi between the groups. The secondary outcomes included respiratory depression, hypo- or hypertension, heart rate (HR), blood pressure, respiratory rate and postoperative outcomes. Additionally, the number of patients who experienced a decrease in intraoperative ORi to < 50% and the associated factors were analyzed. Results: The ORi was significantly higher in the RMMZ group at 15 min after sedation maintenance. There were no significant differences in respiratory depression between the two groups. The intraoperative HR was significantly higher in the RMMZ group after the induction of sedation, 15 min after sedation maintenance, and at the end of surgery. No other results were significantly different between the two groups. The incidence of a decrease in intraoperative ORi to < 50% was significantly higher in the DEX group. Factors associated with a decrease in the intraoperative ORi to < 50% were diabetes mellitus, low baseline peripheral oxygen saturation (SpO2), and DEX use. In the receiver operating characteristic curve analysis for a decrease in the intraoperative ORi to < 50%, the cutoff baseline SpO2 was 97%. Conclusion: RMMZ is recommended as a sedative for patients with a low baseline SpO2 and intraoperative bradycardia. Further studies should be conducted to establish the criteria for a significant ORi reduction.

Application of the New Preoperative Frailty Risk Score in Elderly Patients Undergoing Emergency Surgery.

BACKGROUND: Predicting preoperative frailty risk in emergency surgery is difficult with limited information because preoperative evaluation is not commonly performed properly. A recent study attempted to predict preoperative frailty risk using only diagnostic and surgical codes that can be extracted from the electronic medical records system. OBJECTIVE: This study aimed to validate whether the prediction model of preoperative frailty risk presented in the previous study is well applied to other medical hospitals' data. METHODS: This is a retrospective cohort study including 1,557 patients (≥75 years old) who were admitted to a single institution for emergency operations between January 1, 2010, and December 31, 2019, for study analysis. The Charlson comorbidity index, Hospital Frailty Risk Score, and the recently developed Operation Frailty Risk Score (OFRS) were calculated using the patient's diagnostic and operation codes. The predictive performances of these calculated risk scores and the American Society of Anesthesiologists-Physical Status classification for postoperative 90-day mortality were compared by using the receiver operating characteristic curve analysis. FINDINGS: The predictive performance of the OFRS, Charlson comorbidity index, American Society of Anesthesiologists-Physical Status, and Hospital Frailty Risk Score for postoperative 90-day mortality was 0.81, 0.630, 0.699, and 0.549 on a c-statistics basis, respectively. CONCLUSIONS: The OFRS using diagnostic and operation codes may show the best predictive performance for 90-day mortality compared to other risk scores, and it can be the clinically applicable model to evaluate the preoperative frailty risk in elderly patients undergoing emergency surgery.

Metataxonomic investigation of the microbial community in the trachea and oropharynx of healthy controls and diabetic patients using endotracheal tubes.

BACKGROUND: Although the study of respiratory microbiota has been an active field of research, obtaining the appropriate respiratory samples for healthy controls remains to be a challenge. As such, this study aims to evaluate the use of endotracheal tube washing as a viable control for sputum samples. METHODS: A total of 14 subjects, including 8 healthy respiratory controls and 6 diabetic patients without any respiratory disease, were enrolled in this study, during which the endotracheal tubes used in their scheduled routine surgery were collected. Pre-operative oral gargles were also collected from non-diabetic subjects. RESULTS: 16S amplicon sequencing revealed similar taxa composition in endotracheal tube washings and oral gargles in the healthy control subjects, although the relative abundance of 11 genus level operational taxonomic units was significantly different between the two sample sources. The diabetic subjects showed relatively lower diversity than those of non-diabetic subjects. The proportion range of the most abundant taxa detected in each endotracheal tube washings were 10.1-33.2%. CONCLUSION: Endotracheal tube washing fluid may provide healthy control samples for upper respiratory investigations without incurring any additional risk to the subject.

Predictive Model for the Assessment of Preoperative Frailty Risk in the Elderly.

Adequate preoperative evaluation of frailty can greatly assist in the efficient allocation of hospital resources and planning treatments. However, most of the previous frailty evaluation methods, which are complicated, time-consuming, and can have inter-evaluator error, are difficult to apply in urgent situations. Thus, the authors aimed to develop and validate a predictive model for pre-operative frailty risk of elderly patients by using diagnostic and operation codes, which can be obtained easily and quickly from electronic records. We extracted the development cohort of 1762 people who were hospitalized for emergency operations at a single institution between 1 January 2012 and 31 December 2016. The temporal validation cohort from 1 January 2017 to 31 December 2018 in the same center was set. External validation was conducted on 6432 patients aged 75 years or older from 2012 to 2015 who had emergency surgery in the Korean national health insurance database. We developed the Operation Frailty Risk Score (OFRS) by assessing the association of Operation Group and Hospital Frailty Risk Score with the 90-day mortality through logistic regression analysis. We validated the OFRS in both the temporal validation cohort and two external validation cohorts. In the temporal validation cohort and the external validation cohort I and II, the c-statistics for OFRS to predict 90-day mortality were 0.728, 0.626, and 0.619, respectively. OFRS from these diagnostic codes and operation codes may help evaluate the peri-operative frailty risk before emergency surgery for elderly patients where history-taking and pre-operative testing cannot be performed.

Hyperchloremic metabolic acidosis during bipolar transurethral resection of the prostate: a report of two cases.

Compared with monopolar transurethral resection of the prostate (TURP), which requires electrolyte-free irrigation fluid, normal saline can be used as the irrigation solution in bipolar and laser TURP. The risk of TURP syndrome and severe electrolyte disturbance is minimized when normal saline is used as the irrigation fluid. However, the use of isotonic saline also causes acid-base imbalance and electrolyte disturbance. We experienced two patients who developed hyperchloremic metabolic acidosis during bipolar TURP. After proper intervention, hemodynamic instability resolved, and laboratory test results normalized. Anesthesiologists must pay attention to acid-base and electrolyte status when rapid absorption of excessive isotonic solution is suspected, even during bipolar and laser TURP, which use normal saline as the irrigation fluid.

Correlation between the Perfusion Index and Intraoperative Hypothermia: A Prospective Observational Pilot Study.

Background and Objectives: We examined the association between the baseline perfusion index (PI) and changes in intraoperative body temperature during general anesthesia. The PI reflects the peripheral perfusion state. The PI may be associated with changes in body temperature during general anesthesia because the degree of redistribution of body heat from the central to the peripheral compartment varies depending on the peripheral perfusion state. Materials and Methods: Thirty-eight patients who underwent brain surgery were enrolled in this study. The baseline PI and body temperature of the patients were measured on entering the operating room. Body temperature was recorded every 15 min after induction of anesthesia using an esophageal temperature probe. Univariate and multivariate logistic regression analyses were performed to identify the risk factors for intraoperative hypothermia. Results: Eighteen patients (47 %) developed hypothermia intraoperatively. The baseline PI was significantly lower among patients in the hypothermia group (1.8 ± 0.7) than among those in the normothermia group (3.0 ± 1.2) (P < 0.001). The baseline PI and body temperature were independently associated with intraoperative hypothermia (PI: odds ratio [OR], 0.270; 95% confidence interval [CI], 0.105-0.697; P = 0.007, baseline body temperature: OR, 0.061; 95% CI, 0.005-0.743; P = 0.028). Conclusions: This study showed that low baseline PI was the factor most related to the development of intraoperative hypothermia. Future studies should consider the PI as a predictor of intraoperative hypothermia.

Accuracy of noninvasive continuous arterial pressure monitoring using ClearSight during one-lung ventilation.

ABSTRACT: Noninvasive continuous arterial pressure monitoring may be clinically useful in patients who require continuous blood pressure monitoring in situations where arterial catheter placement is limited. Many previous studies on the accuracy of the noninvasive continuous blood pressure monitoring method reported various results. However, there is no research on the effectiveness of noninvasive arterial pressure monitoring during one-lung ventilation. The purpose of this study was to compare arterial blood pressure obtained through invasive method and noninvasive method by using ClearSight during one-lung ventilation.In this retrospective observational study, a total of 26 patients undergoing one-lung ventilation for thoracic surgery at a single institution between March and July 2019 were recruited. All patients in this study were cannulated on their radial artery to measure continuously invasive blood pressures and applied ClearSight on the ipsilateral side of the cannulated arm. We compared and analyzed the agreement and trendability of blood pressure recorded with invasive and noninvasive methods during one-lung ventilation.Blood pressure and pulse rate showed a narrower limit of agreement with a percentage error value of around 30%. In addition, the tracking ability of each measurement could be determined by the concordance rate, all of which were below acceptable limits (92%).In noninvasive arterial blood pressure monitoring using ClearSight, mean blood pressure and pulse rate show acceptable agreement with the invasive method.

Early Skin Test after Anaphylaxis during Induction of Anesthesia: A Case Report.

BACKGROUND: It is recommended that a skin test be performed 4-6 weeks after anaphylaxis. However, there is little evidence about the timing of the skin test when there is a need to identify the cause within 4-6 weeks. CASE REPORT: A 57-year-old woman was scheduled to undergo surgery via a sphenoidal approach to remove a pituitary macroadenoma. Immediately after the administration of rocuronium, pulse rate increased to 120 beats/min and blood pressure dropped to 77/36 mmHg. At the same time, generalized urticaria and tongue edema were observed. Epinephrine was administered and the surgery was postponed. Reoperation was planned two weeks after the event. Four days after the anaphylactic episode, rocuronium was confirmed to be the cause by the skin prick test. Cisatracurium, which showed a negative reaction, was selected as an alternative agent for future procedures. Two weeks later, the patient underwent reoperation without any adverse events. CONCLUSIONS: The early skin test can be performed if there is a need even earlier than 4-6 weeks after anaphylaxis.

Extracorporeal membrane oxygenation for takotsubo cardiomyopathy that developed after mitral valve replacement.

Takotsubo cardiomyopathy is a transient systolic and diastolic left ventricular dysfunction that presents several wall-motion abnormalities, while the coronary artery shows normal findings. Because patients with Takotsubo cardiomyopathy present with symptoms similar to acute coronary syndrome, the initial diagnosis and treatment are often difficult. The condition is often precipitated by acute emotional or physical stress and frequently occurs in postmenopausal women. Takotsubo cardiomyopathy may also occur in the perioperative period after cardiac and noncardiac surgery; surgery-associated Takotsubo cardiomyopathy reportedly accounts for 3%-23% of all cases. Of these perioperative cases, cardiothoracic surgery accounted for 16%. However, few cases have been reported in patients undergoing cardiac surgery and managed with extracorporeal membrane oxygenation (ECMO). We report a case of Takotsubo cardiomyopathy managed with ECMO in a patient in the intensive care unit after mitral valve replacement.

Use of methylene blue in vasoplegic syndrome that developed during non-cardiac surgery - A case report.

BACKGROUND: Vasoplegic syndrome is an increasingly recognized disease in perioperative medicine and is characterized by severe hypotension, normal or elevated cardiac output, and decreased systemic vascular resistance. It occurs commonly after cardiopulmonary bypass but may also occur after other types of surgery. CASE: Vasoplegic syndrome developed in our patient during posterior lumbar interbody fusion because of administering nicardipine after phenylephrine. However, the blood pressure did not increase as expected despite simultaneous use of norepinephrine and vasopressin to increase the reduced systemic vascular resistance. CONCLUSIONS: We present a case of vasoplegic syndrome that developed during posterior lumbar interbody fusion and was treated successfully with methylene blue.

Transthoracic radiofrequency ablation for hepatic tumor located beneath the diaphragm under one-lung ventilation: A case report.

RATIONALE: Radiofrequency ablation (RFA) has become the reliable, effective, and less invasive treatment for small primary or metastatic hepatic tumors. Hepatic tumors that located immediately beneath the diaphragm are difficult to treat with percutaneous RFA due to poor visualization by percutaneous ultrasonography and the close location of the heart or lung. A transthoracic approach has been proposed to be an alternative for hepatic tumors located beneath the diaphragm that are difficult to access by conventional percutaneous or laparoscopic approaches. There has been no report regarding the anesthetic management of the transthoracic RFA for hepatic tumor. PATIENT CONCERNS: A 69-year-old female had undergone segmentectomy due to hepatocellular carcinoma 4 years ago. DIAGNOSES: Newly developed hepatic tumor located in the liver dome and beneath the diaphragm was diagnosed by follow-up imaging study. INTERVENTIONS: Because the tumor could not be identified by transabdominal ultrasonography (US), transthoracic approach for RFA under one-lung ventilation was planned. General anesthesia was induced with propofol and remifentanil via target-controlled infusion system and rocuronium was administered. Orotracheal intubation with double-lumen endotracheal tube was performed and position of the tube in the trachea was confirmed by bronchoscope. The RFA electrode was introduced percutaneously into the right pleural cavity, guided by visualization through the thoracoscope and inserted into the tumor after visualizing the tumor by US. Radiofrequency waves can be successfully administered through the needle. OUTCOMES: We performed successfully RFA of the hepatic tumor through one-lung ventilation and transthoracic approach. At 5 days postoperatively, she was discharged in a stable condition without any complication. LESSONS: Transthoracic RFA can be successfully performed under one-lung ventilation, optimal analgesia, and vigilant monitoring.

Comparison of analgesic efficacy of oxycodone and fentanyl after total hip replacement surgery: A randomized controlled trial.

BACKGROUND: Total hip replacement (THR) is often accompanied by severe postoperative pain. We aimed to study whether oxycodone can be an effective alternative for fentanyl in the management of early postoperative pain after total hip replacement. METHODS: We conducted a randomized controlled trial on 46 patients scheduled to undergo THR. We followed a standard general anesthetic technique, with endotracheal intubation. Twenty minutes before the end of surgery, single bolus injection of fentanyl, 50 µg (fentanyl group [group F], n = 23) or oxycodone, 4 mg (oxycodone group [group O], n = 23) was administered intravenously. Numeric rating scale (NRS) was used to assess pain in the post-anesthesia care unit (PACU). All patients had intravenous patient-controlled analgesia (PCA) with 10 µg/kg of fentanyl for 48 hours. Intravenous boluses of 50 µg were administered for breakthrough pain. The cumulative opioid dose administered at 6, 12, 24, and 48 h after surgery were recorded. A P value of less than .05 was considered statistically significant. RESULTS: The NRS of group O in the PACU was significantly lower (P <.05); fewer patients in group O required additional fentanyl boluses in the PACU (P <.05). The cumulative opioid requirement was significantly less in group O at 6, 12, 24, and 48 hours after surgery. (P <.05) CONCLUSIONS:: A single bolus injection of oxycodone is more effective than that of fentanyl in the acute phase of postoperative pain after THR. It may be used as an alternative drug for fentanyl in pain control after orthopedic surgery.

Effect of prophylactic palonosetron and sugammadex on postoperative nausea and vomiting in patients undergoing microvascular decompression under propofol-maintained anesthesia: A retrospective observational study.

Microvascular decompression (MVD) is associated with a particularly high risk of postoperative nausea and vomiting (PONV) among craniotomy patients. However, there is no information regarding the effect of prophylactic palonosetron and sugammadex on PONV in patients undergoing MVD under propofol-maintained anesthesia.Medical records of 274 adults who had undergone MVD under propofol-maintained anesthesia were reviewed. Patients were classified into 4 groups, based on the reversal agent used (sugammadex/pyridostigmine) and whether or not prophylactic palonosetron was used. The PONV incidence and risk factors were analyzed according to the use of these agents.The overall incidence of PONV was 30.7% during the first 24 hours postoperatively. The incidence of PONV was lower in the group using combination of prophylactic palonosetron and sugammadex (19.3%) compared with the group not using both agents (37.2%). The combined use of the prophylactic palonosetron and sugammadex was identified as a factor affecting the occurrence of PONV in both univariable (OR = 0.40, 95% CI: 0.21-0.77, P = .006) and multivariable (OR = 0.38, 95% CI: 0.20-0.75, P = .005) logistic regression analyses. In multivariable logistic regression analysis, female sex was also significant independent risk factor in PONV (OR = 2.62, 95% CI: 1.35-5.08, P = .004).In this retrospective observational study, the combined use of prophylactic palonosetron before anesthetic induction and sugammadex as a reversal of neuromuscular blockade are associated with a reduction in the incidence of PONV in patients undergoing MVD under propofol-maintained anesthesia.

Effect of remifentanil during drug-induced sleep endoscopy in patients with obstructive sleep apnea.

PURPOSE: During drug-induced sleep endoscopy (DISE) in patients with obstructive sleep apnea, the increased depth of propofol anesthesia is related to the increased collapsibility of the upper airway with dose-dependent. We examined the effect of remifentanil on propofol concentration during DISE. METHODS: In a prospective randomized trial, 56 adult patients were divided into remifentanil-propofol (n = 28) and propofol alone (n = 28) groups. Anesthesia was administered using a target-controlled infusion system. In the remifentanil-propofol group, 0.5 ng/ml remifentanil was administered prior to propofol infusion and its concentration maintained; thereafter, in the propofol alone group, normal saline was injected instead of remifentanil. Propofol was infused at a concentration of 1.5 µg/ml after the target concentration of remifentanil was reached. In both groups, the concentration of propofol was increased by 0.5 µg/ml if the degree of sedation was not sufficient. The sedation level was targeted at observer's assessment of alertness/sedation (OAA/S) scale 3. RESULTS: The mean propofol concentration was 2.87 ± 0.60 µg/ml in the remifentanil-propofol group, which was lower than that in the propofol alone group (3.38 ± 0.72 µg/ml, P < 0.001). The time until sufficient sedation to perform DISE was shorter in the remifentanil-propofol group (P < 0.001). Apnea-hypopnea index and the lowest peripheral capillary oxygen saturation (SpO2) during polysomnography showed no statistical difference between groups (P > 0.05). The lowest SpO2 and VOTE classification during DISE were also not statistically different (P > 0.05). CONCLUSIONS: Use of remifentanil during DISE reduces the target concentration of propofol required for patient sedation to perform DISE without respiratory depression.

Replacement of dexmedetomidine loading with midazolam for sedation in elderly patients with spinal anesthesia.

BACKGROUND: Dexmedetomidine is an effective sedative during spinal anesthesia. However, it requires a loading dose, which can result in transient hypertension, hypotension, bradycardia, and/or sinus arrest. In addition, the time required to reach an appropriate depth of sedation may cause anxiety to the patients. Therefore, we examined whether an intravenous bolus of midazolam could replace the loading dose of dexmedetomidine for sedation during surgery in elderly patients who received spinal anesthesia. METHODS: Patients aged over 60 years who scheduled to undergo total knee arthroplasty under spinal anesthesia were enrolled in this study. The patients were randomized into 2 groups. Patients in dexmedetomidine group (group D) (n = 20) were administered a loading dose of dexmedetomidine (1.0 µg/kg over 10 min) intravenously followed by dexmedetomidine maintenance (0.5 µg/kg/h). Patients in group MD (n = 20) were administered an intravenous midazolam (0.05 mg/kg) followed by dexmedetomidine maintenance (0.5 µg/kg/h) intravenously. Heart rate (HR), mean arterial blood pressure (MBP), peripheral oxygen saturation (SpO2), and patient state index (PSI) were recorded. Ramsay sedation scale (RSS) scores were evaluated at 10 minutes after drug administration and the end of surgery. RESULTS: A total of 40 subjects were enrolled in the present study. At baseline, there was no between-group difference in HR. Ten minutes after drug administration, group D had lower HR than group MD (62.1 ±â€Š9.4 versus 69.6 ±â€Š13.4, P = .047). PSI was significantly lower in group MD at 10 minutes after drug administration (82.8 ±â€Š13.0 versus 72.0 ±â€Š16.0, P = .024); there was no between-group difference at 30 and 60 minutes, and lower values in group D at the end of surgery (70.2 ±â€Š22.6 versus 79.7 ±â€Š10.9, P = .011). The RSS score showed statistically significantly deeper sedation in group MD 10 minutes after drug administration, but no difference at the end of surgery. CONCLUSIONS: An intravenous bolus of midazolam is a viable alternative to dexmedetomidine loading for sedation during surgery in elderly patients who received spinal anesthesia. This is especially effective for patients who are at high risk for bradycardia or who want a faster sedation.