Development of extended pharmacokinetic models for propofol based on measured blood and brain concentrations.

Propofol's pharmacokinetics have been extensively studied using human blood samples and applied to target-controlled infusion systems; however, information on its concentration in the brain remains scarce. Therefore, this study aimed to simultaneously measure propofol plasma and brain concentrations in patients who underwent awake craniotomy and establish new pharmacokinetic model. Fifty-seven patients with brain tumors or brain lesions who underwent awake craniotomy were sequentially assigned to model-building and validating groups. Plasma and brain (lobectomy or uncapping margins) samples were collected at five time-points. The concentration of propofol was measured using high-performance liquid chromatography. Population pharmacokinetic analysis was conducted through a nonlinear mixed-effects modeling program using a first-order conditional estimation method with interactions. Propofol's brain concentrations were higher than its plasma concentrations. The measured brain concentrations were higher than the effect site concentrations using the previous models. Extended models were constructed based on measured concentrations by incorporating the brain/plasma partition coefficient (Kp value). Extended models showed good predictive accuracy for brain concentrations in the validating group. The Kp value functioned as a factor explaining retention in the brain. Our new pharmacokinetic models and Kp value can predict propofol's brain and plasma concentrations, contributing to safer and more stable anesthesia.

Remimazolam in perioperative management of Eisenmenger syndrome: a case report.

BACKGROUND: Eisenmenger syndrome (ES) is characterized by severe and irreversible pulmonary hypertension stemming from an uncorrected intracardiac shunt of significant size. The imbalance between systemic and pulmonary artery pressures predisposes patients with ES to the risk of cardiac arrest. Remimazolam has caused less circulatory depression, which may be advantageous for ES. However, no studies reported the use of remimazolam in perioperative ES management. CASE PRESENTATION: A 45-year-old female patient with ES derived from a ventricular septal defect was scheduled to undergo bilateral adnexectomy for an ovarian tumor. Her oxygen saturation was 80% with 3 L/min oxygen at rest, and her pulmonary and systemic flow ratio was 0.53. She underwent general anesthesia with remimazolam, and intraoperative hemodynamics was stable without hypotension or reduced oxygen saturation. CONCLUSIONS: Our successful management of ovarian tumor surgery in a patient with ES using remimazolam reveals its potential effectiveness in perioperative care.

Critical care bed capacity in Asian countries and regions before and during the COVID-19 pandemic: an observational study.

Background: The coronavirus disease 2019 (COVID-19) pandemic highlighted the importance of critical care. The aim of the current study was to compare the number of adult critical care beds in relation to population size in Asian countries and regions before (2017) and during (2022) the pandemic. Methods: This observational study collected data closest to 2022 on critical care beds (intensive care units and intermediate care units) in 12 middle-income and 7 high-income economies (using the 2022-2023 World Bank classification), through a mix of methods including government sources, national critical care societies, personal contacts, and data extrapolation. Data were compared with a prior study from 2017 of the same countries and regions. Findings: The cumulative number of critical care beds per 100,000 population increased from 3.0 in 2017 to 9.4 in 2022 (p = 0.003). The median figure for middle-income economies increased from 2.6 (interquartile range [IQR] 1.7-7.8) to 6.6 (IQR 2.2-13.3), and that for high-income economies increased from 11.4 (IQR 7.3-22.8) to 13.9 (IQR 10.7-21.7). Only 3 countries did not see a rise in bed capacity. Where data were available in 2022, 10.9% of critical care beds were in single rooms (median 5.0% in middle-income and 20.3% in high-income economies), and 5.3% had negative pressure (median 0.7% in middle-income and 18.5% in high-income economies). Interpretation: Critical care bed capacity in the studied Asian countries and regions increased close to three-fold from 2017 to 2022. Much of this increase was attributed to middle-income economies, but substantial heterogeneity exists. Funding: None.

Dexmedetomidine versus haloperidol for sedation of non-intubated patients with hyperactive delirium during the night in a high dependency unit: study protocol for an open-label, parallel-group, randomized controlled trial (DEX-HD trial).

BACKGROUND: Delirium is common in critically ill patients. Haloperidol has long been used for the treatment of delirium. Dexmedetomidine has recently been used to treat delirium among intubated critically ill patients. However, the efficacy of dexmedetomidine for delirium in non-intubated critically ill patients remains unknown. We hypothesize that dexmedetomidine is superior to haloperidol for sedation of patients with hyperactive delirium, and would reduce the prevalence of delirium among non-intubated patients after administration. We will conduct a randomized controlled trial to compare dexmedetomidine and haloperidol for the treatment of nocturnal hyperactive delirium in non-intubated patients in high dependency units (HDUs). METHODS: This is an open-label, parallel-group, randomized controlled trial to compare the efficacy and safety of dexmedetomidine and haloperidol for nocturnal hyperactive delirium in non-intubated patients at two HDUs of a tertiary hospital. We will recruit consecutive non-intubated patients who are admitted to the HDU from the emergency room, and allocate them in a 1:1 ratio to the dexmedetomidine or haloperidol group in advance. The allocated investigational drug will be administered only when participants develop hyperactive delirium (Richmond Agitation-Sedation Scale [RASS] score ≥1 and a positive score on the Confusion Assessment Method for the ICU between 19:00 and 6:00 the next day) during the night at an HDU. Dexmedetomidine is administered continuously, while haloperidol is administered intermittently. The primary outcome is the proportion of participants who achieve the targeted sedation level (RASS score of between -3 and 0) 2h after the administration of the investigational drug. Secondary outcomes include the sedation level and prevalence of delirium on the day following the administration of the investigational drugs, and safety. We plan to enroll 100 participants who develop nocturnal hyperactive delirium and receive one of the two investigational drugs. DISCUSSION: This is the first randomized controlled trial to compare the efficacy and safety of dexmedetomidine and haloperidol for sedation of non-intubated critically ill patients with hyperactive delirium in HDUs. The results of this study may confirm whether dexmedetomidine could be another option to sedate patients with hyperactive delirium. TRIAL REGISTRATION: Japan Registry of Clinical Trials, jRCT1051220015, registered on 21 April 2022.

Association between intraoperative end-tidal carbon dioxide and postoperative organ dysfunction in major abdominal surgery: A cohort study.

BACKGROUND: Data on the effects of intraoperative end-tidal carbon dioxide (EtCO2) levels on postoperative organ dysfunction are limited. Thus, this study was designed to investigate the relationship between the intraoperative EtCO2 level and postoperative organ dysfunction in patients who underwent major abdominal surgery under general anesthesia. METHODS: We conducted a cohort study involving patients who underwent major abdominal surgery under general anesthesia at Kyoto University Hospital. We classified those with a mean EtCO2 of less than 35 mmHg as low EtCO2. The time effect was determined as the minutes when the EtCO2 value was below 35 mmHg, whereas the cumulative effect was evaluated by measuring the area below the 35-mmHg threshold. The outcome was postoperative organ dysfunction, defined as a composite of at least one organ dysfunction among acute renal injury, circulatory dysfunction, respiratory dysfunction, coagulation dysfunction, and liver dysfunction within 7 days after surgery. RESULTS: Of the 4,171 patients, 1,195 (28%) had low EtCO2, and 1,428 (34%) had postoperative organ dysfunction. An association was found between low EtCO2 and increased postoperative organ dysfunction (adjusted risk ratio, 1.11; 95% confidence interval [CI], 1.03-1.20; p = 0.006). Additionally, long-term exposure to EtCO2 values of less than 35 mmHg (≥224 min) was associated with postoperative organ dysfunction (adjusted risk ratio, 1.18; 95% CI, 1.06-1.32; p = 0.003) and low EtCO2 severity (area under the threshold) (adjusted risk ratio, 1.13; 95% CI, 1.02-1.26; p = 0.018). CONCLUSIONS: Intraoperative low EtCO2 of below 35 mmHg was associated with increased postoperative organ dysfunction.

Agreement between continuous cardiac output measured by the fourth-generation FloTrac/Vigileo system and a pulmonary artery catheter in adult liver transplantation.

In liver transplantation for end-stage liver failure, monitoring of continuous cardiac output (CCO) is used for circulatory management due to hemodynamic instability. CCO is often measured using the minimally invasive FloTrac/Vigileo system (FVS-CCO), instead of a highly invasive pulmonary artery catheter (PAC-CCO). The FVS has improved accuracy due to an updated cardiac output algorithm, but the effect of this change on the accuracy of FVS-CCO in liver transplantation is unclear. In this study, we assessed agreement between fourth-generation FVS-CCO and PAC-CCO in 20 patients aged ≥ 20 years who underwent scheduled or emergency liver transplantation at Kyoto University Hospital from September 2019 to June 2021. Consent was obtained before surgery and data were recorded throughout the surgical period. Pearson correlation coefficient (r), Bland-Altman and 4-quadrant plot analyses were performed on the extracted data. A total of 1517 PAC-CCO vs. FVS-CCO data pairs were obtained. The mean PAC-CCO was 8.73 L/min and the mean systemic vascular resistance was 617.5 dyne·s·cm-5, r was 0.48, bias was 1.62 L/min, the 95% limits of agreement were - 3.04 to 6.27, and the percentage error was 54.36%. These results show that agreement and trending between fourth-generation FVS-CCO and PAC-CCO are low in adult liver transplant recipients.

Relationship between the Use of Fentanyl-Based Intravenous Patient-Controlled Analgesia and Clinically Significant Events in Laparoscopic Gynecological Surgery: A Single-Center Retrospective Cohort Study.

Background: This study examined the relationship between the use of fentanyl-based intravenous patient-controlled analgesia (ivPCA) and the incidence of a clinically significant event (CSE), while considering both the analgesic effects and side effects in laparoscopic gynecological surgery. Methods: This study included 816 patients undergoing laparoscopic gynecological surgery under general anesthesia at Kyoto University Hospital between 2012 and 2018. The primary exposure was the use of fentanyl-based ivPCA. We defined an outcome measure­CSE­that integrates severe wound pain and vomiting assumed to negatively affect patient recovery. We performed multivariable logistic regression analysis to assess the independent relationship between ivPCA use and CSE. Results: Multivariable logistic regression analysis revealed that fentanyl-based ivPCA was independently associated with increased CSE (adjusted odds ratio (95% confidence interval): 1.80 (1.24−2.61), p = 0.002). Use of ivPCA was associated with a reduced incidence of postoperative severe wound pain (adjusted odds ratio (95% confidence interval): 0.50 (0.27−0.90), p = 0.022), but was also associated with an increased incidence of vomiting (adjusted odds ratio (95% confidence interval): 2.65 (1.79−3.92), p < 0.001). Conclusion: The use of fentanyl-based ivPCA in laparoscopic gynecological surgery is associated with increased CSE.

Association between intraoperative end-tidal carbon dioxide and postoperative nausea and vomiting in gynecologic laparoscopic surgery.

Gynecologic laparoscopic surgery has a high incidence of postoperative nausea and vomiting (PONV). Studies suggest that low intraoperative end-tidal carbon dioxide (EtCO2) is associated with an increased incidence of PONV, but the results have not been consistent among studies. This study investigated the association between intraoperative EtCO2 and PONV in patients undergoing gynecologic laparoscopic surgeries under general anesthesia. This retrospective cohort study involved patients who underwent gynecologic laparoscopic surgeries under general anesthesia at Kyoto University Hospital. We defined low EtCO2 as a mean EtCO2 of < 35 mmHg. Multivariable modified Poisson regression analysis examined the association between low EtCO2 and PONV during postoperative two days and the postoperative length of hospital stay (PLOS). Of the 739 patients, 120 (16%) had low EtCO2, and 430 (58%) developed PONV during postoperative two days. There was no substantial association between low EtCO2 and increased incidence of PONV (adjusted risk ratio: 0.96; 95% confidence interval [CI] 0.80-1.14; p = 0.658). Furthermore, there was no substantial association between low EtCO2 and prolonged PLOS (adjusted difference in PLOS: 0.13; 95% CI - 1.00 to 1.28; p = 0.816). Intraoperative low EtCO2, specifically a mean intraoperative EtCO2 below 35 mmHg, was not substantially associated with either increased incidence of PONV or prolonged PLOS.

A Nationwide Questionnaire Survey on Awake Craniotomy in Japan.

The number of awake craniotomies is increasing because of its beneficial features. However, not enough information is available regarding the current status of awake craniotomy in Japan. To evaluate the current status of awake craniotomy in institutes, a nationwide questionnaire survey was conducted. From June to August 2019, we conducted a questionnaire survey on awake craniotomy in the neurosurgery department of 45 institutes that perform awake craniotomies in Japan. Responses were obtained from 39 institutes (response rate, 86.7%). The main methods of awake craniotomy were almost the same in all institutes. Twenty-six institutes (66.7%) had fewer than 10 awake craniotomies (low-volume institutes) per year, and 13 high-volume institutes (33.3%) performed more than 10 awake craniotomies annually. Some institutes experienced a relatively high frequency of adverse events. In 11 institutes (28.2%), the frequency of intraoperative seizures was more than 10%. An intraoperative seizure frequency of 1%-9%, 10%-29%, and over 30% was identified in 12 (92%), 0 (0%), and 1 (8%) of the high-volume institutes, which was significantly less than in 16 (62%), 10 (38%), and 0 (0%) of the low-volume institutes (p = 0.0059). The routine usage of preoperative antiepileptic drugs was not different between them, but the old type was used more often in the low-volume institutes (p = 0.0022). Taken together, the annual number of awake craniotomies was less than 10 in over two-thirds of the institutes. Fewer intraoperative seizures were reported in the high-volume institutes, which tend not to preoperatively use the old type of antiepileptic drugs.

Incidence, clinical characteristics and long-term prognosis of postoperative symptomatic venous thromboembolism: a retrospective cohort study.

OBJECTIVES: The purpose of this study was to evaluate the incidence, clinical characteristics and prognosis of postoperative symptomatic venous thromboembolism (VTE) in Japan. DESIGN: Retrospective observational study. Two data sets, Contemporary ManageMent AND outcomes in patients with Venous ThromboEmbolism (COMMAND VTE) Registry and Japanese Society of Anesthesiologists (JSA) annual report, were used for current analyses. SETTING: Eighteen of 29 centres participated in the COMMAND VTE Registry. PARTICIPANTS: Acute symptomatic patients with VTE who had undergone surgery 2 months prior to the diagnosis at 18 centres from January 2010 to December 2013 were identified in the COMMAND VTE Registry. From each centre's JSA annual report, the overall population that had received anaesthetic management during this period was retrieved. INTERVENTIONS: None. PRIMARY AND SECONDARY OUTCOME MEASURES: The primary outcome was the incidences and clinical characteristics of postoperative symptomatic VTE. The secondary outcomes were recurrent VTE, major bleeding and all-cause death. RESULTS: We identified 137 patients with postoperative symptomatic VTE, including 57 patients with pulmonary embolism. The incidences of postoperative symptomatic VTE and pulmonary embolism were 0.067% and 0.028%, respectively, based on data from 2 03 943 patients who underwent surgery, managed by anaesthesiologists, during the study period. The incidences of postoperative symptomatic VTE varied widely, depending on surgical and anaesthetic characteristics. Postoperative symptomatic VTE occurred at a median of 8 days after surgery, with 58 patients (42%) diagnosed within 7 days. The cumulative incidence, 30 days after VTE, of recurrent VTE, major bleeding, and all-cause death was 3.0%, 5.2%, and 3.7%, respectively. CONCLUSION: This study, combining the large real-world VTE and anaesthesiology databases in Japan revealed the incidence, clinical features and prognosis of postoperative symptomatic VTE, providing useful insights for all healthcare providers involved in various surgeries. TRIAL REGISTRATION: Not applicable.

Intraoperative hand strength as an indicator of consciousness during awake craniotomy: a prospective, observational study.

Awake craniotomy enables mapping and monitoring of brain functions. For successful procedures, rapid awakening and the precise evaluation of consciousness are required. A prospective, observational study conducted to test whether intraoperative hand strength could be a sensitive indicator of consciousness during the awake phase of awake craniotomy. Twenty-three patients who underwent awake craniotomy were included. Subtle changes of the level of consciousness were assessed by the Japan Coma Scale (JCS). The associations of hand strength on the unaffected side with the predicted plasma concentration (Cp) of propofol, the bispectral index (BIS), and the JCS were analyzed. Hand strength relative to the preoperative maximum hand strength on the unaffected side showed significant correlations with the Cp of propofol (ρ = - 0.219, p = 0.007), the BIS (ρ = 0.259, p = 0.002), and the JCS (τ = - 0.508, p = 0.001). Receiver operating characteristic curve analysis for discriminating JCS 0-1 and JCS ≥ 2 demonstrated that the area under the curve was 0.76 for hand strength, 0.78 for Cp of propofol, and 0.66 for BIS. With a cutoff value of 75% for hand strength, the sensitivity was 0.76, and the specificity was 0.67. These data demonstrated that hand strength is a useful indicator for assessing the intraoperative level of consciousness during awake craniotomy.

Intraoperative end-tidal carbon dioxide and postoperative mortality in major abdominal surgery: a historical cohort study.

PURPOSE: There is a paucity of data on the effect of intraoperative end-tidal carbon dioxide (EtCO2) levels on postoperative mortality. The purpose of this study was to investigate the relationship between intraoperative EtCO2 and 90-day mortality in patients undergoing major abdominal surgery under general anesthesia. METHODS: We conducted a historical cohort study of patients undergoing major abdominal surgery under general anesthesia at Kyoto University Hospital. We measured the intraoperative EtCO2, and patients with a mean EtCO2 value < 35 mm Hg were classified as low EtCO2. The time effect was determined based on minutes below an EtCO2 of 35 mm Hg, and cumulative effects were evaluated by measuring the area under the threshold of 35 mm Hg for each patient. RESULTS: Of 4,710 patients, 1,374 (29%) had low EtCO2 and 55 (1.2%) died within 90 days of surgery. Multivariable Cox regression analysis-adjusted for age, American Society of Anesthesiologists Physical Status classification, sex, laparoscopic surgery, emergency surgery, blood loss, mean arterial pressure, duration of surgery, type of surgery, and chronic obstructive pulmonary disease-revealed an association between low EtCO2 and 90-day mortality (adjusted hazard ratio, 2.2; 95% confidence interval [CI], 1.2 to 3.8; P = 0.006). In addition, severity of low EtCO2 was associated with an increased 90-day mortality (area under the threshold; adjusted hazard ratio; 2.9, 95% CI, 1.2 to 7.4; P =0.02); for long-term exposure to an EtCO2 < 35 mm Hg (≥ 226 min), the adjusted hazard ratio for increased 90-day mortality was 2.3 (95% CI, 0.9 to 6.0; P = 0.08). CONCLUSION: A mean intraoperative EtCO2 < 35 mm Hg was associated with increased postoperative 90-day mortality.

RéSUMé: OBJECTIF: Il n'existe que très peu de données s'intéressant à l'effet du niveau peropératoire télé-expiratoire du dioxyde de carbone (EtCO2) sur la mortalité postopératoire. L'objectif de cette étude était d'examiner la relation entre l'EtCO2 peropératoire et la mortalité à 90 jours chez des patients subissant une chirurgie abdominale majeure sous anesthésie générale. MéTHODE: Nous avons réalisé une étude de cohorte historique portant sur des patients subissant une chirurgie abdominale majeure sous anesthésie générale à l'Hôpital universitaire de Kyoto. Nous avons mesuré l'EtCO2 peropératoire, et les patients avec une valeur moyenne d'EtCO2 < 35 mmHg ont été catégorisés comme EtCO2 faible. L'effet temps a été déterminé en fonction de la durée, en minutes, avec une EtCO2 inférieure à 35 mmHg, et les effets cumulatifs ont été évalués en mesurant l'aire sous le seuil de 35 mmHg pour chaque patient. RéSULTATS: Sur 4710 patients, 1374 (29 %) avaient une EtCO2 faible et 55 (1,2 %) sont décédés dans les 90 jours suivant la chirurgie. Une analyse de régression multivariée de Cox, ajustée pour tenir compte des facteurs suivants : âge, statut physique selon l'American Society of Anesthesiologists, sexe, chirurgie par laparoscopie, chirurgie d'urgence, pertes de sang, tension artérielle moyenne, durée de la chirurgie, type de chirurgie et maladie pulmonaire obstructive chronique, a révélé une association entre une EtCO2 faible et la mortalité à 90 jours (rapport de risque ajusté, 2,2; intervalle de confiance [IC] à 95 %, 1,2 à 3,8; P = 0,006). De plus, la sévérité de l'EtCO2 basse était associée à une augmentation de la mortalité à 90 jours (aire sous le seuil; rapport de risque ajusté; 2,9, IC 95 %, 1,2 à 7,4; P =0,02); pour une exposition à long terme à une EtCO2 < 35 mmHg (≥ 226 minutes), le rapport de risque ajusté pour une mortalité accrue à 90 jours était de 2,3 (IC 95 %, 0,9 à 6,0 ; P = 0,08). CONCLUSION: Une EtCO2 peropératoire moyenne < 35 mmHg était associée à une augmentation de la mortalité postopératoire à 90 jours.

Factors associated with somnolence during brain function mapping in awake craniotomy.

Somnolence during brain function mapping is one of the factors that inhibit the accomplishment of the goals of awake craniotomy. We examined the effect of anesthesia depth measured by bispectral index (BIS) during pre-awake phase on somnolence during brain function mapping and also explored the factors associated with somnolence. We examined the association between BIS values during pre-awake phase and somnolence during the first 30 min of brain function mapping in 55 patients who underwent awake craniotomy at Kyoto University Hospital from 2015 to 2018. The pre-awake BIS value was defined as the mean BIS value for 60 min before the removal of the airway. Somnolence during brain function mapping was the primary outcome, defined as either of the following conditions: inability to follow up, disorientation, or inability to assess speech function. Additionally, we compared patient or perioperative variables between patients with/without somnolence. Somnolence occurred in 14 patients (25.5%), of which 6 patients (10.9%) were unable to complete brain function mapping. There was no significant difference in the pre-awake BIS value between patients with/without somnolence (median: 46 vs. 49, P = 0.192). Somnolence was not significantly associated with age, gender, and the number of preoperative anticonvulsive drugs, but patients with somnolence had a significantly lower preoperative Western Aphasia Battery (WAB) aphasia quotient score (median 93.8 vs. 98.6, P = 0.011). We did not find an association between pre-awake BIS value and somnolence during brain function mapping. Somnolence likely occurs in patients with a low preoperative WAB aphasia quotient score.

Knot formation in a thoracic epidural catheter: a case report.

BACKGROUND: Although most epidural catheter knot formation has been reported in lumbar epidural catheter placement, knot formation in a thoracic epidural catheter has been experienced. CASE PRESENTATION: A 72-year-old woman was scheduled for laparoscopic cholecystectomy under general anesthesia combined with epidural anesthesia. The epidural catheter was inserted through the Th10-Th11 intervertebral space and was placed 7 cm into the epidural space. Two days after the surgery, the anesthesiologist was called because of difficulty in removing the epidural catheter. The catheter was eventually removed when the anesthesiologist carefully pulled it while strongly bending the patient's body to the right, although resistance was still noted. The removed catheter was observed to have a hard single knot formed at about 3 mm from the tip. CONCLUSIONS: A knot formation of an epidural catheter placed at the thoracic level was experienced. Limiting the length of catheter placement may prevent knot formation.

The association between arterial pulse waveform analysis device and in-hospital mortality in high-risk non-cardiac surgeries.

BACKGROUND: Perioperative goal-directed fluid therapy is used for haemodynamic optimization in high-risk surgeries. Cardiac output monitoring can be performed by a specialized pressure transducer for arterial pulse waveform analysis (S-APWA). No study has assessed whether real-world use of S-APWA is associated with post-operative outcomes; therefore, using a Japanese administrative claims database, we retrospectively investigated whether S-APWA use is associated with in-hospital mortality among patients undergoing high-risk surgery under general anaesthesia. METHODS: Adult patients who underwent high-risk surgery under general anaesthesia and arterial catheterization between 2014 and 2016 were divided into S-APWA and conventional arterial pressure transducer groups, then compared regarding baseline factors and outcomes. Logistic regression analysis was performed to compare in-hospital mortality. Subgroup analyses evaluated S-APWA efficacy and outcomes based on the type of surgery and patients' comorbidity. RESULTS: S-APWA was used in 6859 of 23 655 (29.0%) patients; the crude in-hospital mortality rate was 3.5%. Adjusted analysis showed no significant association between S-APWA use and in-hospital mortality rate (adjusted odds ratio [aOR] = 0.91; 95% confidence interval [CI]: 0.76-1.07; P = .25). S-APWA use was associated with significantly lower in-hospital mortality in patients undergoing vascular surgery (aOR = 0.67; 95% CI: 0.49-0.94), and significantly higher in-hospital mortality in patients undergoing lower limb amputation (aOR = 2.63; 95% CI: 1.32-5.22). S-APWA use and in-hospital mortality were not significantly associated with other subgroups. CONCLUSION: S-APWA use was not associated with in-hospital mortality in the entire study population. However, S-APWA was associated with decreased in-hospital mortality among vascular surgery and increased in-hospital mortality among lower limb amputation.

Effects of low-dose remifentanil infusion on analgesic or antiemetic requirement during brain function mapping: A retrospective cohort study.

BACKGROUND: Pain and discomfort during the awake phase in awake craniotomy should be relieved to facilitate brain mapping. Although some anaesthesiologists use low-dose (0.01-0.05 µg/kg/min) remifentanil infusion to provide analgesia during this phase, its efficacy and side effects have never been evaluated. Therefore, this study primarily aimed to investigate the effects of low-dose remifentanil infusion on the need for antiemetic treatment during brain mapping and secondarily aimed to determine its effects on the need for additional analgesic treatment. METHODS: This retrospective study included 218 patients who underwent awake craniotomy at our centre from 2008 to 2018. The relationship between low-dose remifentanil infusion during the awake phase and the requirement for analgesic or antiemetic treatment was examined. A multivariable competing risk regression analysis was performed to adjust for patient and operative variables. RESULTS: Sixty-six patients (30.3%) received low-dose (median rate: 0.01 µg/kg/min) remifentanil infusion during the awake phase. Forty-nine patients (22.5%) received an antiemetic and 99 (45.4%) received additional analgesic treatment. The difference in additional analgesic treatment was not significant between patients who received low-dose remifentanil infusion and those who did not (adjusted hazard ratio: 1.13; 95% confidence interval: 0.75-1.70; P = .570); however, the use of antiemetics significantly increased in patients who received remifentanil (adjusted hazard ratio: 1.78; 95% confidence interval: 1.01-3.15; P = .047). CONCLUSION: Low-dose remifentanil infusion during the awake phase in awake craniotomy significantly increased the need for antiemetics but did not decrease the need for additional analgesic treatment.