Artificial intelligence model predicting postoperative pain using facial expressions: a pilot study.

PURPOSE: This study aimed to assess whether an artificial intelligence model based on facial expressions can accurately predict significant postoperative pain. METHODS: A total of 155 facial expressions from patients who underwent gastric cancer surgery were analyzed to extract facial action units (AUs), gaze, landmarks, and positions. These features were used to construct various machine learning (ML) models, designed to predict significant postoperative pain intensity (NRS ≥ 7) from less significant pain (NRS < 7). Significant AUs predictive of NRS ≥ 7 were determined and compared to AUs known to be associated with pain in awake patients. The area under the receiver operating characteristic curves (AUROCs) of the ML models was calculated and compared using DeLong's test. RESULTS: AU17 (chin raising) and AU20 (lip stretching) were found to be associated with NRS ≥ 7 (both P ≤ 0.004). AUs known to be associated with pain in awake patients did not show an association with pain in postoperative patients. An ML model based on AU17 and AU20 demonstrated an AUROC of 0.62 for NRS ≥ 7, which was inferior to a model based on all AUs (AUROC = 0.81, P = 0.006). Among facial features, head position and facial landmarks proved to be better predictors of NRS ≥ 7 (AUROC, 0.85-0.96) than AUs. A merged ML model that utilized gaze and eye landmarks, as well as head position and facial landmarks, exhibited the best performance (AUROC, 0.90) in predicting significant postoperative pain. CONCLUSION: ML models using facial expressions can accurately predict the presence of significant postoperative pain and have the potential to screen patients in need of rescue analgesia. TRIAL REGISTRATION NUMBER: This study was registered at ClinicalTrials.gov (NCT05477303; date: June 17, 2022).

Comparison of the Effect of Landmark-Based Midline and Paramedian Approaches on Spinal Anesthesia-Related Complications in Adult Patients: A Meta-Analysis of Randomized Controlled Trials.

Background and Objectives: Spinal anesthesia is widely used in various types of surgery. However, several complications can occur afterward. This study aimed to identify differences in the incidence of anesthesia-related complications according to the approach methods (midline versus paramedian) for landmark-based spinal anesthesia. Materials and Methods: We searched electronic databases, including PubMed, EMBASE, CENTRAL, Scopus, and Web of Science, for eligible randomized controlled trials. The primary outcome was post-dural puncture headache (PDPH) incidence, and secondary outcomes were low back pain (LBP) incidence and success rate in the first trial of spinal anesthesia. We estimated the odds ratio (OR) with 95% confidence intervals (CI) using a random-effects model. Results: In total, 2280 patients from 13 randomized controlled trials were included in the final analysis. The incidence rates of PDPH were 5.9% and 10.4% in the paramedian and midline approach groups, respectively. The pooled effect size revealed that the incidence of PDPH (OR: 0.43, 95% CI [0.22-0.83]; p = 0.01; I2 = 53%) and LBP (OR: 0.27, 95% CI [0.16-0.44]; p < 0.001; I2 = 16%) decreased, and the success rate in the first attempt was higher (OR: 2.30, 95% CI [1.36-3.87]; p = 0.002; I2 = 35%) with the paramedian than with the midline approach. Conclusions: Paramedian spinal anesthesia reduced PDPH and LBP and increased the success rate of the first attempt.

Postoperative Delirium after Dexmedetomidine versus Propofol Sedation in Healthy Older Adults Undergoing Orthopedic Lower Limb Surgery with Spinal Anesthesia: A Randomized Controlled Trial.

BACKGROUND: Delirium is a critical postoperative complication in older patients. Based on the hypothesis that intraoperative dexmedetomidine sedation would lower postoperative delirium than propofol sedation would, the authors compared the incidence of postoperative delirium in older adults, using the mentioned sedatives. METHODS: This double-blinded, randomized controlled study included 748 patients, aged 65 yr or older, who were scheduled for elective lower extremity orthopedic surgery, between June 2017 and October 2021. Patients were randomized equally into two groups in a 1:1 ratio according to the intraoperative sedative used (dexmedetomidine vs. propofol). The postoperative delirium incidence was considered the primary outcome measure; it was determined using the confusion assessment method, on the first three postoperative days. The mean arterial pressure and heart rate were evaluated as secondary outcomes. RESULTS: The authors enrolled 732 patients in the intention-to-treat analyses. The delirium incidence was lower in the dexmedetomidine group than in the propofol group (11 [3.0%] vs. 24 [6.6%]; odds ratio, 0.42; 95% CI, 0.201 to 0.86; P = 0.036). During sedation, the mean arterial pressure (median [interquartile range] mmHg) was higher in the dexmedetomidine group (77 [71 to 84]) than in the propofol group (74 [69 to 79]; P < 0.001); however, it significantly fell lower (74 [68 to 80]) than that of the propofol group (80 [74 to 87]) in the postanesthesia care unit (P < 0.001). Lower heart rates (beats/min) were recorded with the use of dexmedetomidine than with propofol, both during sedation (60 [55 to 66] vs. 63 [58 to 70]) and in the postanesthesia care unit (64 [58 to 72] vs. 68 [62-77]; P < 0.001). CONCLUSIONS: Dexmedetomidine showed a lower incidence of postoperative delirium than propofol in healthy older adults undergoing lower extremity orthopedic surgery.

Effect of the Paravertebral Block on Chronic Postsurgical Pain After Thoracic Surgery: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

OBJECTIVE: This study aimed to identify the benefits of thoracic paravertebral block (PVB) by focusing on its role in reducing chronic postsurgical pain (CPSP) after thoracic surgery. DESIGN: A systematic review and meta-analysis of randomized controlled trials (RCTs). SETTING: Electronic databases, including PubMed, EMBASE, CENTRAL, Scopus, and Web of Science, were searched to identify studies. PARTICIPANTS: Patients undergoing thoracic surgeries. INTERVENTION: Paravertebral block for postoperative analgesia. MEASUREMENT AND MAIN RESULTS: A total of 1,028 adult patients from 10 RCTs were included in the final analysis. The incidence of CPSP at 3 months after surgery was not reduced in the PVB group compared with the no-block (odds ratio [OR] 0.59, 95% CI 0.34-1.04; p = 0.07; I2 = 6.96%) and other-block (OR 1.39, 95% CI 0.30-6.42; p = 0.67; I2 = 77.75%) groups. The PVB did not significantly reduce the incidence of CPSP after 6 months from surgery when compared with no block (OR 0.44, 95% CI 0.08-2.53; p = 0.36; I2 = 87.53%) and other blocks (OR 1.17, 95% CI 0.71-1.95; p = 0.93; I2 = 45.75%). The PVB significantly decreased postoperative pain at 24 and 48 hours at rest compared with the no- block group. The pain score was higher in the PVB group than in the other block groups 48 hours after surgery at rest. CONCLUSIONS: Thoracic PVB does not prevent CPSP after thoracic surgery. Further large RCTs are required to confirm and validate the authors' results.

The effect of intranasal dexmedetomidine administration on emergence agitation or delirium in pediatric patients after general anesthesia: A meta-analysis of randomized controlled trials.

BACKGROUND: Emergence agitation or delirium can occur in pediatric patients after anesthesia. Dexmedetomidine is known to reduce the impairment of postoperative cognitive function. AIMS: This study aimed to identify the role of intranasal administration of dexmedetomidine in lowering the development of emergence agitation or emergence delirium in pediatric patients after general anesthesia. METHODS: Electronic databases, including PubMed, EMBASE, CENTRAL, Scopus, and Web of Science, were searched to identify studies. The primary outcome was the proportion of patients who underwent emergence agitation or emergence delirium after the surgery. Secondary outcomes included emergence time and incidence of postoperative nausea and/or vomiting. We estimated the odds ratio and mean difference with 95% confidence intervals for the determination of effect size using a random-effects model. RESULTS: In total, 2103 pediatric patients from 20 randomized controlled trials were included in the final analysis. The incidence of emergence agitation or emergence delirium was 13.6% in the dexmedetomidine group and 33.2% in the control group. The pooled effect size revealed that intranasal dexmedetomidine administration significantly reduced the incidence of postoperative emergence agitation or emergence delirium in pediatric patients undergoing surgery under general anesthesia (odds ratio 0.25, 95% confidence interval 0.18-0.34; p = .0000; I2 = 37.74%). Additionally, significant difference was observed in emergence time between the two groups (mean difference 2.42, 95% confidence interval 0.37-4.46; p = .021; I2 = 98.40%). Children in the dexmedetomidine group had a significantly lower incidence of postoperative nausea and/or vomiting than those in the control group (odds ratio 0.39, 95% confidence interval 0.24-0.64; p = .0002; I2 = 0.00%). CONCLUSIONS: Intranasal dexmedetomidine reduced the incidence of emergence agitation or emergence delirium in pediatric patients after general anesthesia.

Intraoperative 5-HT3 receptor antagonists decrease the prevalence of postoperative delirium in older adults undergoing hip fracture surgery: a single-center retrospective study.

PURPOSE: Postoperative delirium (POD) occurs commonly in older adults, resulting in unfavorable outcomes. Several recent clinical studies have suggested that 5-hydroxytryptamine 3 (5-HT3) receptor antagonists can treat and prevent POD. In this retrospective study, the association between 5-HT3 receptor antagonists and POD was investigated in older adults who underwent hip fracture surgery. METHODS: The electronic medical records of older adults aged ≥ 65 years who underwent hip fracture surgery between January 2011 and June 2018 were reviewed retrospectively. Multivariable logistic regression analysis was used to investigate the association between 5-HT3 receptor antagonists and the occurrence of POD. In addition to the incidence of POD, anesthesia-, surgery-, and patient-related factors related to POD were evaluated. RESULTS: Of the 1025 patients included, 813 (79.3%) were administered 5-HT3 receptor antagonists intraoperatively; 471 (45.9%) were administered ramosetron, and 342 (33.4%) were administered palonosetron. POD was identified in 242 patients (23.6%). Ramosetron and palonosetron reduced the POD incidence by 53% (odds ratio [OR] 0.47; 95% confidence interval [CI] 0.32‒0.71; P < 0.001) and 41% (OR 0.59; 95% CI 0.39‒0.89; P = 0.011), respectively. Additionally, age, American Society of Anesthesiologists physical status class 4, and male were confirmed as risk factors for POD. CONCLUSION: Intraoperative 5-HT3 receptor antagonists may be associated with a reduced risk of POD and can be considered one of the preventive strategies for POD in older adults undergoing hip fracture surgery.

Ultrasound assessment of gastric volume in older adults after drinking carbohydrate-containing fluids: a prospective, nonrandomized, and noninferiority comparative study.

PURPOSE: The aim of this study was to evaluate the safety of drinking carbohydrate-containing fluids two hours prior to surgery in older adults using ultrasonography. METHODS: We conducted a nonrandomized and noninferiority comparative study in 60 patients aged over 65 yr who were scheduled for total knee arthroplasty. Patients who were fasted from midnight (fasting group) or who drank 400 mL of a carbohydrate-containing fluid (carbohydrate ingestion group) two hours prior to surgery were matched for age, sex, and body mass index. We measured the cross-sectional area (CSA) of gastric antrum using ultrasound and estimated the gastric fluid volume as the study's primary outcome measure. The noninferiority margin (δ) for the mean difference was predefined as 50 mL. The secondary outcome measures included CSA of the antrum and qualitative gastric volume. RESULTS: The mean (standard deviation) gastric volume was not significantly different between the fasting group and the carbohydrate ingestion group (30.2 [25.4] mL vs 28.4 [35.8] mL; each group, n = 30; P = 0.81). The mean difference in gastric volume was -1.9 mL (95% confidence interval [CI], -17.9 to 14.2), and the upper limit of the 95% CI was lower than the prespecified noninferiority limit (δ = 50 mL). Secondary outcomes were not significantly different between the two groups. CONCLUSION: Drinking of carbohydrate-containing fluid two hours prior to surgery was noninferior to overnight fasting with respect to residual gastric volume at induction of anesthesia in healthy older adults who undergoing total knee arthroplasty. STUDY REGISTRATION: ClinicalTrials.gov (NCT04514380); registered 14 August 2020.

RéSUMé: OBJECTIF: L'objectif de cette étude était d'évaluer l'innocuité de la consommation d'une préparation glucidique deux heures avant une chirurgie chez les personnes âgées à l'aide de l'échographie. MéTHODE: Nous avons mené une étude comparative non randomisée et de non-infériorité chez 60 patients âgés de plus de 65 ans qui devaient bénéficier d'une arthroplastie totale du genou. Les patients étaient à jeun depuis minuit (groupe à jeun) ou avaient bu 400 mL d'une préparation glucidique (groupe d'ingestion de glucides) deux heures avant la chirurgie et ont été appariés pour l'âge, le sexe et l'indice de masse corporelle. Nous avons mesuré la section transversale de l'antre gastrique à l'aide de l'échographie et estimé le volume de liquide gastrique en tant que mesure du critère d'évaluation principal de l'étude. La marge de non-infériorité (δ) pour la différence moyenne a été prédéfinie à 50 mL. Les mesures de critères d'évaluation secondaires comprenaient la section transversale de l'antre et le volume gastrique qualitatif. RéSULTATS: Le volume gastrique moyen (écart type) n'était pas significativement différent entre le groupe à jeun et le groupe d'ingestion de glucides (30,2 [25,4] mL vs 28,4 [35,8] mL; chaque groupe, n = 30; P = 0,81). La différence moyenne de volume gastrique était de -1,9 mL (intervalle de confiance [IC] à 95 %, -17,9 à 14,2), et la limite supérieure de l'IC 95 % était inférieure à la limite de non-infériorité prédéfinie (δ = 50 mL). Aucune différence intergroupe significative n'a été observée dans les critères d'évaluation secondaires. CONCLUSION: La consommation d'une préparation glucidique deux heures avant la chirurgie n'était pas inférieure au jeûne nocturne en ce qui concerne le volume gastrique résiduel à l'induction de l'anesthésie chez les personnes âgées en bonne santé qui bénéficient d'une arthroplastie totale du genou. ENREGISTREMENT DE L'éTUDE: www.ClinicalTrials.gov (NCT04514380); enregistrée le 14 août 2020.

Total intravenous anesthesia induced and maintained by a combination of remimazolam and remifentanil without a neuromuscular blocking agent: a prospective, observational pilot study.

BACKGROUND: A novel short-acting benzodiazepine, Remimazolam, has recently been approved for general anesthesia and sedation. Hence, we investigated the feasibility and safety of remimazolam during the induction and maintenance of general anesthesia without using a neuromuscular blocking agent (NMBA) in patients undergoing hysteroscopic surgery. METHODS: This prospective observational study included 38 patients undergoing hysteroscopic surgery. Remimazolam and remifentanil were the main anesthetic agents without an NMBA, and a supraglottic airway was inserted to protect the airway. The induction time, amount of each anesthetic agent used during anesthesia, intraoperative bispectral index (BIS) hemodynamic parameters, and recovery profiles were measured. RESULTS: General anesthesia was successfully administered to 37 patients using remimazolam and remifentanil without NMBA. The induction doses of remimazolam and remifentanil were 0.4 mg/kg (interquartile range [IQR] 0.34-0.47 mg/kg) and 1.07 µg/kg (IQR, 0.90-1.29 µg/kg), respectively. Additionally, the maintenance doses of remimazolam and remifentanil were 1.14 mg/kg/h (IQR, 0.88-1.55 mg/kg/h) and 0.06 µg/kg/min (IQR, 0.04-0.08 µg/kg/min), respectively. Intraoperative BIS values had risen temporarily > 60 in eight patients (21.6%) despite administration of 2 mg/kg/h of remimazolam; thus, they were treated with supplementary midazolam. The median recovery time was 7 min (IQR, 5-8 min) after 40 min (IQR, 40.0-57.5 min) of total mean anesthesia time. There was no correlation between the infusion dose of remimazolam and recovery profiles, such as recovery time, final BIS of anesthesia, modified observer assessment of alertness/sedation (OAA/S) scale or post-anesthesia recovery (PAR) score when arriving at the PACU, and length of stay in the PACU (all P > 0.05). CONCLUSION: Remimazolam can be combined with remifentanil without an NMBA in female patients who undergo hysteroscopic surgery, during which a supraglottic airway is a feasible method to protect the airway. TRIAL REGISTRATION: The study protocol was registered at ClinicalTrials.gov (NCT05025410) on 27/08/2021.

Efficacy of Erector Spinae Plane Block for Analgesia in Thoracic Surgery: A Systematic Review and Meta-Analysis.

OBJECTIVE: The objective of this study was to determine whether erector spinae plane block (ESPB) can provide an effective analgesia for managing pain after thoracic surgery and compare the efficacy of ESPB with that of other regional analgesic techniques. DESIGN: Systematic review and meta-analysis of randomized controlled trials. SETTING: PubMed, EMBASE, CENTRAL, CINAHL, Scopus, and Web of Science were searched. PARTICIPANTS: Patients undergoing thoracic surgeries. INTERVENTION: Erector spinae plane block with local anesthetics for postoperative analgesia. MEASUREMENT AND MAIN RESULTS: Seventeen studies, including 1,092 patients, were included in the final analysis. Erector spinae plane block reduced 24-hour postoperative opioid consumption (mean difference [MD] -17.49, 95% CI -26.87 to -8.12), pain score at rest (MD -0.82, 95% CI -1.31 to -0.33), and pain score at movement (MD -0.77, 95% CI -1.20 to -0.3) compared to no block. Compared with other regional blocks, various results have been observed. Although statistical results showed that ESPB is inferior to thoracic paravertebral block and intercostal nerve block and superior to serratus anterior plan block in postoperative analgesia, clinical differences remain unclear. The incidence of hematoma was lower in the ESPB group than in the other groups (odds ratio 0.19, 95% CI 0.05-0.73). CONCLUSION: Erector spinae plane block may provide effective analgesia after thoracic surgery. Compared with other techniques, it is a safer method, without clinically important differences, for postoperative pain control. Therefore, ESPB may be considered as a valuable option for postoperative pain management after thoracic surgery.

Role of Unfolded Protein Response and Endoplasmic Reticulum-Associated Degradation by Repeated Exposure to Inhalation Anesthetics in Caenorhabditis elegans.

Background: When an imbalance occurs between the demand and capacity for protein folding, unfolded proteins accumulate in the endoplasmic reticulum (ER) lumen and activate the unfolded protein response (UPR). In addition, unfolded proteins are cleared from the ER lumen for ubiquitination and subsequent cytosolic proteasomal degradation, which is termed as the ER-associated degradation (ERAD) pathway. This study focused on changes in the UPR and ERAD pathways induced by the repeated inhalation anesthetic exposure in Caenorhabditis elegans. Methods: Depending on repeated isoflurane exposure, C. elegans was classified into the control or isoflurane group. To evaluate the expression of a specific gene, RNA was extracted from adult worms in each group and real-time polymerase chain reaction was performed. Ubiquitinated protein levels were measured using western blotting, and behavioral changes were evaluated by chemotaxis assay using various mutant strains. Results: Isoflurane upregulated the expression of ire-1 and pek-1 whereas the expression of atf-6 was unaffected. The expression of both sel-1 and sel-11 was decreased by isoflurane exposure, possibly indicating the inhibition of retro-translocation. The expression of cdc-48.1 and cdc-48.2 was decreased and higher ubiquitinated protein levels were observed in the isoflurane group than in the control, suggesting that deubiquitination and degradation of misfolded proteins were interrupted. The chemotaxis indices of ire-1, pek-1, sel-1, and sel-11 mutants decreased significantly compared to N2, and they were not suppressed further even after the repeated isoflurane exposure. Conclusion: Repeated isoflurane exposure caused significant ER stress in C. elegans. Following the increase in UPR, the ERAD pathway was disrupted by repeated isoflurane exposure and ubiquitinated proteins was accumulated subsequently. UPR and ERAD pathways are potential modifiable neuroprotection targets against anesthesia-induced neurotoxicity.

Immediate retrograde amnesia induced by midazolam: A prospective, non-randomised cohort study.

BACKGROUND: Midazolam, a short-acting benzodiazepine, has sedative, anxiolytic, amnestic and anticonvulsant effects. Given its advantages of rapid onset, short duration and low toxicity, midazolam is optimal for any procedural sedation. Midazolam is known to cause anterograde amnesia; however, the possibility of retrograde amnesia has also been raised. This prospective cohort, non-randomised study evaluated the presence and extent of retrograde amnesia induced by midazolam during caesarean delivery. METHODS: One hundred parturients scheduled for elective caesarean delivery under spinal anaesthesia were enrolled. As soon as giving birth, six picture cards were shown to the patients in 1-min intervals, and then midazolam (0.1 mg/kg) was given or not according to the patients' preference. This overall retrograde recall rate of six cards was the primary outcome of our study, which was asked by a blinded investigator. RESULTS: The overall retrograde card recall rate was lower in the midazolam group compared with the control group (77.0 ± 13.4 vs. 87.7 ± 3.9%, P < .001), especially at 1 minute before midazolam administration (58% vs. 88%, P < .001). Decreased memory trend was observed as time progressed towards midazolam administration in the midazolam group (P = .035). More patients answered 'yes' to the factitious event in the midazolam group than in the control group (26% vs. 4%, P = .004). CONCLUSION: Intravenous midazolam could cause a brief-period retrograde amnesia in visual and event memory. Moreover, there were more spurious reports of intraoperative factitious events in the midazolam group, implying that episodic memories were also affected by midazolam.

Immediate retrograde amnesia induced by midazolam: a prospective, nonrandomized cohort study.

BACKGROUND: Midazolam, a short-acting benzodiazepine, has sedative, anxiolytic, amnestic, and anticonvulsant effect. Given its advantages of rapid onset, short duration, and low toxicity, midazolam is optimal for any procedural sedation. Midazolam is known to cause anterograde amnesia; however, the possibility of retrograde amnesia has also been raised. This prospective cohort, nonrandomized study evaluated the presence and extent of retrograde amnesia induced by midazolam during cesarean delivery. METHODS: One-hundred parturients scheduled for elective cesarean delivery under spinal anesthesia were enrolled. As soon as giving birth, 6 picture cards were shown to the patients in one min intervals, and then midazolam (0.1 mg/kg) was given or not according to the patients' preference. This overall retrograde recall rate of six cards was the primary outcome of our study, which was asked by a blinded investigator. RESULTS: The overall retrograde card recall rate was lower in the midazolam group compared to the control group (77.0 ± 13.4 vs. 87.7 ± 3.9%, p <0.001), especially at one min before midazolam administration (58 vs. 88%, p <0.001). Decreased memory trend was observed as time progressed toward midazolam administration in the midazolam group (p = 0.035). More patients answered 'yes' to the factitious event in the midazolam group than in the control group (26% vs. 4%, p = 0.004). CONCLUSION: Intravenous midazolam could cause a brief-period retrograde amnesia in visual and event memory. Moreover, there were more spurious reports of intraoperative factitious events in the midazolam group, implying that episodic memories were also affected by midazolam.

Effects of dexmedetomidine on blood coagulation: an in vitro study using rotational thromboelastometry.

PURPOSE: To assess the effects of various concentrations of dexmedetomidine on the human blood coagulation profile using rotational thromboelastometry (ROTEM). METHODS: Venous blood samples were collected from 11 healthy volunteers and divided into four specimen bottles; dexmedetomidine was added to attain final sample concentrations of 0, 0.5, 1.0, and 1.5 ng/mL. ROTEM was performed on each study sample. RESULTS: The concentration of dexmedetomidine increased, and the ROTEM values showed a hypercoagulable state. The change in clotting time (CT) for INTEM was larger in samples with a dexmedetomidine concentration of 1.5 ng/mL (- 34%) than in the 0.5 ng/mL samples (- 16%) (P = 0.010). The change in clot formation time (CFT) for INTEM was greater in 1.5 ng/mL samples (- 16%) than in 0.5 ng/mL samples (- 4%) (P = 0.004). A greater decrease in CT for EXTEM was identified in the 1.0 ng/mL and 1.5 ng/mL samples (- 36% and - 37%, respectively) than in the 0.5 ng/mL samples (- 12%) (P = 0.003 for both categories). The change in CFT for EXTEM was greater in the 1.0 ng/mL and 1.5 ng/mL samples (- 11% and - 13%, respectively) than in the 0.5 ng/mL samples (- 4%) (P = 0.006 and P = 0.001, respectively). A bigger change in maximum clot firmness (MCF) for EXTEM was observed in the 1.5 ng/mL samples (4%) than in the 0.5 ng/mL samples (0%) (P = 0.002). The change in MCF for FIBTEM was greater in the 1.5 ng/mL samples (19%) than in the 0.5 ng/mL samples (5%) (P = 0.001). CONCLUSIONS: All coagulation pathways showed a hypercoagulable state as the concentration of dexmedetomidine increased. Nevertheless, most of the values of ROTEM were maintained within the reference ranges. Clinical Trial NCT04269278.

Retrospective Comparison between the Effects of Propofol and Inhalation Anesthetics on Postoperative Recurrence of Early- and Intermediate-Stage Hepatocellular Carcinoma.

OBJECTIVE: Previous studies have reported that propofol has antitumor, anti-inflammatory, and antioxidant effects in addition to its anesthetic properties. To confirm this, a retrospective investigation was conducted to determine whether different anesthetic agents, particularly propofol and inhalation anesthetics, have an effect on the recurrence of hepatocellular carcinoma (HCC) in patients who were diagnosed with primary HCC and underwent laparoscopic hepatectomy. SUBJECTS AND METHODS: Patients with Barcelona Clinic Liver Cancer stages 0, A, and B HCC, who underwent laparoscopic hepatic resection, were enrolled in this study. Post-operative HCC recurrence, which was determined from postoperative liver CT, was evaluated 24 months postoperatively with respect to the main anesthetic agents. The characteristics of HCC and other patient-related or surgery-related variables were evaluated together. RESULTS AND CONCLUSION: During the 24-month period after hepatic resection, less HCC patients in the propofol group than in the inhalation group recurred (p = 0.046). The mean time to recurrence was 20.8 months (95% CI, 19.7-22.0) and 19.1 months (95% CI, 17.8-20.4) in the propofol group and the inhalation group, respectively. In addition, multivariable Cox proportional regression analysis revealed that the propofol group showed significantly decreased recurrence versus the inhalation group (hazard ratio, 0.57; 95% CI, 0.47-0.69; p = 0.029). When propofol was used as the main general anesthetic agent for laparoscopic hepatic resection, the postoperative 2-year recurrence rate decreased in early- and intermediate-stage HCC.

Comparison of Intraoperative Sedation With Dexmedetomidine Versus Propofol on Acute Postoperative Pain in Total Knee Arthroplasty Under Spinal Anesthesia: A Randomized Trial.

BACKGROUND: In patients undergoing total knee arthroplasty under spinal anesthesia, we compared the postoperative analgesic effect of intraoperative sedation with dexmedetomidine versus propofol. We hypothesized that sedation with dexmedetomidine would result in lower postoperative opioid analgesic consumption than with propofol. METHODS: Forty-eight patients were enrolled and randomly assigned to either a dexmedetomidine group (n = 24), which received a loading dose of 1 µg/kg dexmedetomidine over 10 minutes, followed by a continuous infusion of 0.1-0.5 µg·kg·hour, or a propofol group (n = 24), which received a continuous infusion of propofol via a target-controlled infusion to maintain the effect-site concentration within a range of 0.5-2.0 µg/mL. The drug infusion rate was determined according to the sedation level, targeting a modified observer's assessment of alertness/sedation score of 3 or 4. The cumulative amounts of fentanyl administered via intravenous patient-controlled analgesia were recorded at 24 and 48 hours postoperatively (primary outcome). The postoperative numerical rating scale for pain was assessed at 6, 12, 24, and 48 hours (secondary outcome). The postoperative use of additional rescue analgesic (ketoprofen) and antiemetic drugs was also compared between the 2 groups at 24 and 48 hours. RESULTS: Dexmedetomidine significantly reduced postoperative fentanyl consumption (median [interquartile range]) during 0-24 hours (45 [30-71] vs 150 [49-248] µg, P = .004; median difference = -105 µg [99.98% CI, 210-7.5]), 24-48 hours (90 [45-143] vs 188 [75-266] µg, P = .005; median difference = -98 µg [99.98% CI, 195-45]), and 0-48 hours (135 [68-195] vs 360 [146-480] µg, P = .003; median difference = -225 µg [99.98% CI, 405-7.5]). The numerical rating scale (median [interquartile range]) was lower at 6 hours (1 [0-2] vs 2 [1-3], P = .003), 12 hours (1 [1-2] vs 3 [2-3], P < .001), 24 hours (1 [1-2] vs 3 [2-3], P < .001), and 48 hours (2 [2-3] vs 3 [3-4], P < .001) after surgery in the dexmedetomidine group compared to the propofol group. No significant intergroup differences were observed in the amount of rescue analgesics and antiemetics at 24 hours (P = .155 and P = .482) and 48 hours (P = .082 and P = .153) after surgery. CONCLUSIONS: Intraoperative dexmedetomidine sedation was associated with a small but clinically important reduction in postoperative opioid use after total knee arthroplasty.

Association of Preoperative Serum Chloride Levels With Mortality and Morbidity After Noncardiac Surgery: A Retrospective Cohort Study.

BACKGROUND: Postoperative hyperchloremia is known to be related to increases in mortality and morbidity after surgery. However, the relationship between preoperative hyperchloremia and hypochloremia and postoperative mortality and morbidity is not well established. Our aim was to evaluate the relationship between preoperative hyperchloremia or hypochloremia, as assessed using preoperative serum chloride tests, and 90-day mortality and morbidity after noncardiac surgery. METHODS: In this retrospective cohort study, we reviewed the medical records of patients >20 years of age who underwent noncardiac surgery between January 2010 and December 2016. Patients were categorized into one of the following groups on the basis of the results of serum chloride testing performed within 1 month before surgery: normochloremia, 97-110 mmol·L; hyperchloremia, >110 mmol·L; and hypochloremia, <97 mmol·L. The primary end point of this study was the difference in postoperative 90-day mortality among the preoperative serum chloride groups. The secondary end point was the difference in postoperative acute kidney injury incidence among the preoperative serum chloride groups. RESULTS: A total of 106,505 patients were included in the final analysis (2147 were allocated to the preoperative hypochloremia group and 617 to the hyperchloremia group). Multivariable Cox regression analysis revealed significantly increased 90-day mortality in the hypochloremia (hazard ratio, 1.46; 95% CI, 1.16-1.84; P = .001) and hyperchloremia (hazard ratio, 1.76; 95% CI, 1.13-2.73; P = .013) groups when compared with the normochloremia group. In addition, multivariable logistic regression analysis revealed a 1.83-fold increased odds of acute kidney injury in the preoperative hypochloremia group when compared with the normochloremia group (odds ratio, 1.83; 95% CI, 1.53-2.19; P < .001). CONCLUSIONS: Preoperative hypochloremia and hyperchloremia were related to increased 90-day mortality after noncardiac surgery. In addition, preoperative hypochloremia was related to an increased risk for postoperative acute kidney injury.

Comparison of standard versus 90° rotation technique for LMA Flexible™ insertion: a randomized controlled trial.

BACKGROUND: Insertion of a flexible laryngeal mask airway (LMA Flexible) is known to be more difficult than that of a conventional laryngeal mask airway. The 90° rotation technique can improve the success rate with a conventional laryngeal mask airway but its effect with the LMA Flexible remains unknown. We assessed whether the 90° rotation technique increased the first-attempt success rate of LMA Flexible insertion versus the standard technique. METHODS: In total, 129 female patients undergoing breast surgery were analyzed. The primary endpoint was success at the first attempt. The insertion time, number of trials, number of manipulations required, and oropharyngeal leak pressure were also evaluated. Heart rate and mean blood pressure were recorded 1 min before and 1 min after insertion. Blood staining on the LMA Flexible after removal and postoperative sore throat were checked. RESULTS: The first-attempt success rates were comparable between the groups (93% vs. 98.3%, P = .20). The insertion time, number of trials and manipulations, hemodynamic variables, and complications, such as blood staining and sore throat, did not differ between the groups. CONCLUSIONS: The 90° rotation technique is a good alternative to the standard technique for insertion of the LMA Flexible. TRIAL REGISTRATION: ClinicalTrials.gov ( NCT03028896 ). It was registered retrospectively at Jan 19th, 2017.

A Comparison of Hemostatic Properties between Monopolar and Bipolar Hysteroscopic Surgery using Rotational Thromboelastometry: A Randomized Trial.

OBJECTIVE: Systemic absorption of irrigation fluid can lead to a disturbed coagulation cascade. We compared the changes in hemostatic properties on using nonelectrolyte solution in monopolar hysteroscopic surgery (HS) with that on using isotonic saline in bipolar HS via rotational thromboelastometry (ROTEM) analysis. METHODS: A total of 54 patients were randomized into 2 groups: 1 group underwent monopolar HS using a mixture of 2.7% sorbitol and 0.54% mannitol (the HSMP group), whereas the other group underwent bipolar HS using 0.9% isotonic saline (the HSBP group). The effects of these 2 methods on coagulation were assessed via pre and postoperative laboratory tests, including estimation of the international normalized ratio of prothrombin time and activated partial thromboplastin time and ROTEM analysis. In addition, the hemoglobin, hematocrit, and electrolyte levels and the platelet count were analyzed. RESULTS: Patient characteristics, volume of irrigation fluid absorbed, and type of procedure were comparable between the 2 groups. There were no significant differences in the pre and postoperative values of ROTEM parameters between the 2 groups. Most postoperative ROTEM parameters, as compared with preoperative values, changed in both groups; clot formation time was prolonged, and the α-angle and maximum clot firmness were decreased. All ROTEM parameters were maintained within the normal range. Hematological parameters, including hemoglobin and hematocrit levels and platelet count, were significantly decreased postoperatively in both groups compared to the preoperative values. No pre and postoperative hematological and hemostatic parameters were significantly different between the 2 groups. CONCLUSION: Irrigation fluid absorbed in healthy women during HS caused hypocoagulable changes in the blood, irrespective of the irrigant type, and no significant differences between HS using monopolar and bipolar electrodes were demonstrated.

Comparison of upper airway patency in patients with mild obstructive sleep apnea during dexmedetomidine or propofol sedation: a prospective, randomized, controlled trial.

BACKGROUND: In addition to propofol, dexmedetomidine is a suitable alternative for intraoperative sedation in procedures requiring regional anesthesia. To date, however, little is known about the influences of each drug on upper airway patency. Accordingly, the authors investigated differences between dexmedetomidine and propofol sedation in the occurrence of upper airway obstruction and requirements for airway intervention in patients with mild obstructive sleep apnea. METHODS: Patients with an apnea/hypopnea index of 5-14/h according to Watch-PAT 200 analysis were enrolled in this study. Spinal anesthesia was routinely performed for surgery. Intraoperative sedation was initiated using either dexmedetomidine or propofol infusion at a level of modified observer's assessment of alertness/sedation scale 3. The primary outcome was the proportion of patients exhibiting signs of upper airway obstruction. A sign of upper airway obstruction was defined as no detection of end-tidal carbon dioxide for at least 10 s despite respiratory efforts. RESULTS: A total of 50 patients were included in the final analysis (dexmedetomidine [n = 26]; propofol [n = 24]). During the intraoperative sedation period, there was a significantly lower proportion of patients exhibiting signs of upper airway obstruction in the dexmedetomidine group than in the propofol group (11.5% vs. 41.7%, P = 0.035). An artificial airway was inserted in 1 patients (3.8%) and 5 patient (20.8%) in the dexmedetomidine and propofol groups, respectively (P = 0.093). CONCLUSION: Dexmedetomidine sedation was associated with a lower incidence of upper airway obstruction than propofol sedation in patients with mild obstructive sleep apnea. TRIAL REGISTRATION NUMBER: Clinical trials.gov ( NCT02993718 ): Retrospectively registered.