Anesthetic Events Research Articles

Incidence and risk factors of chronic opioid use after sleep apnea surgery.

To assess the incidence and risk factors of chronic opioid use after obstructive sleep apnea surgery. Using IBM MarketScan research database, adults (>18 years) who underwent a variety of sleep surgery procedures between 2007 and 2015 were identified. Individuals with 1 year of insurance coverage before and after the surgical procedure were included. Additional anesthesia event(s) in the year following the procedure of interest and those who filled an opioid prescription within the year prior to surgery (not naive) were excluded. Outcomes included rates of persistent opioid use (additional opioid prescriptions filled 90-180 days postoperatively), prolonged use (additional opioid prescriptions filled 181-365 days postoperatively), and inappropriate use (> 100 morphine milligram equivalents). Evaluated variables include demographics, surgical procedures, and comorbidities. A total of 10,766 surgical procedures met the inclusion criteria. There was a trend of increased rates of perioperative opioid prescription. After multivariable logistic regression analysis, perioperative opioid prescription and smoking were independent risk factors for inappropriate opioid use (odds ratio [OR] = 31.51, P < .001; OR = 1.41, P = .016, respectively). Opioid prescription and hypertension were independent risk factors for persistent opioid use (OR = 37.8, P < .001, OR = 1.38, P = .008). Perioperative opioid prescription, previous opioid dependence diagnosis, smoking, and male sex were associated with continuous prolonged opioid use (OR = 73.1, 8.13, 1.95, and 1.55, respectively; P < .001, P = .020, P = .024, and P = .032, respectively). While efforts by different societies are being implemented to control the opioid crisis, we found that perioperative opioid prescription for airway surgery targeting obstructive sleep apnea is an independent risk factor for persistent, prolonged, and inappropriate opioid use. Abdelwahab M, Marques S, Howard J, et al. Incidence and risk factors of chronic opioid use after sleep apnea surgery. J Clin Sleep Med. 2022;18(7):1805-1813.

Neuraxial anesthesia for post-operative pain control after hip surgery in children with cerebral palsy and pre-existing intrathecal baclofen pumps.

The purpose of this study is to describe the efficacy and adverse events of neuraxial anesthesia for post-operative pain control in non-ambulatory children with cerebral palsy with pre-existing intrathecal baclofen (ITB) pumps undergoing hip reconstructive or palliative surgery. Twelve children (mean age 11.25 years) were included in the study with the following neuraxial anesthesia methods: indwelling epidural catheter (8 patients), neuraxial opioids administered through the side port of the ITB pump (3 patients), and single injection spinal anesthetic (1 patient). Observational pain scores and opioid requirements were quantified for all patients. There were no ITB pump or surgical complications at a mean follow-up of 2.2 years. The average length of stay was 6 days. Patients had good post-operative pain control with a mean observational pain score of 0.7 and mean morphine equivalent use of 0.26mg/kg/day. Four patients required anti-emetics to control nausea and three patients had urinary retention requiring repeat catheterization, but all medical complications resolved prior to discharge. Neuraxial anesthesia can effectively control post-operative pain in children with a pre-existing ITB pump. Utilizing the side port of the ITB pump for administration of neuraxial opioids is an option when epidural or spinal anesthesia is not possible.

Visual Attention of Anesthesia Providers in Simulated Anesthesia Emergencies Using Conventional Number-Based and Avatar-Based Patient Monitoring: Prospective Eye-Tracking Study.

BackgroundInadequate situational awareness accounts for two-thirds of preventable complications in anesthesia. An essential tool for situational awareness in the perioperative setting is the patient monitor. However, the conventional monitor has several weaknesses. Avatar-based patient monitoring may address these shortcomings and promote situation awareness, a prerequisite for good decision making.ObjectiveThe spatial distribution of visual attention is a fundamental process for achieving adequate situation awareness and thus a potential quantifiable surrogate for situation awareness. Moreover, measuring visual attention with a head-mounted eye-tracker may provide insights into usage and acceptance of the new avatar-based patient monitoring modality.MethodsThis prospective eye-tracking study compared anesthesia providers' visual attention on conventional and avatar-based patient monitors during simulated critical anesthesia events. We defined visual attention, measured as fixation count and dwell time, as our primary outcome. We correlated visual attention with the potential confounders: performance in managing simulated critical anesthesia events (task performance), work experience, and profession. We used mixed linear models to analyze the results.ResultsFifty-two teams performed 156 simulations. After a manual quality check of the eye-tracking footage, we excluded 57 simulations due to technical problems and quality issues. Participants had a median of 198 (IQR 92.5-317.5) fixations on the patient monitor with a median dwell time of 30.2 (IQR 14.9-51.3) seconds. We found no significant difference in participants' visual attention when using avatar-based patient monitoring or conventional patient monitoring. However, we found that with each percentage point of better task performance, the number of fixations decreased by about 1.39 (coefficient –1.39; 95% CI –2.44 to –0.34; P=.02), and the dwell time diminished by 0.23 seconds (coefficient –0.23; 95% CI: –0.4 to –0.06; P=.01).ConclusionsUsing eye tracking, we found no significant difference in visual attention when anesthesia providers used avatar-based monitoring or conventional patient monitoring in simulated critical anesthesia events. However, we identified visual attention in conjunction with task performance as a surrogate for situational awareness.

User Perceptions of Different Vital Signs Monitor Modalities During High-Fidelity Simulation: Semiquantitative Analysis.

BackgroundPatient safety during anesthesia is crucially dependent on the monitoring of vital signs. However, the values obtained must also be perceived and correctly classified by the attending care providers. To facilitate these processes, we developed Visual-Patient-avatar, an animated virtual model of the monitored patient, which innovatively presents numerical and waveform data following user-centered design principles. After a high-fidelity simulation study, we analyzed the participants’ perceptions of 3 different monitor modalities, including this newly introduced technique.ObjectiveThe aim of this study was to collect and evaluate participants’ opinions and experiences regarding 3 different monitor modalities, which are Visual-Patient-avatar, Split Screen (avatar and Conventional monitor alongside each other), and Conventional monitor after using them during simulated critical anesthetic events.MethodsThis study was a researcher-initiated, single-center, semiquantitative study. We asked 92 care providers right after finishing 3 simulated emergency scenarios about their positive and negative opinions concerning the different monitor modalities. We processed the field notes obtained and derived the main categories and corresponding subthemes following qualitative research methods.ResultsWe gained a total of 307 statements. Through a context-based analysis, we identified the 3 main categories of “Visual-Patient-avatar,” “Split Screen,” and “Conventional monitor” and divided them into 11 positive and negative subthemes. We achieved substantial interrater reliability in assigning the statements to 1 of the topics. Most of the statements concerned the design and usability features of the avatar or the Split Screen mode.ConclusionsThis study semiquantitatively reviewed the clinical applicability of the Visual-Patient-avatar technique in a high-fidelity simulation study and revealed the strengths and limitations of the avatar only and Split Screen modality. In addition to valuable suggestions for improving the design, the requirement for training prior to clinical implementation was emphasized. The responses to the Split Screen suggest that this symbiotic modality generates better situation awareness in combination with numerical data and accurate curves. As a subsequent development step, a real-life introduction study is planned, where we will test the avatar in Split Screen mode under actual clinical conditions.

Referral Indications for Malignant Hyperthermia Susceptibility Diagnostics in Patients without Adverse Anesthetic Events in the Era of Next-generation Sequencing.

The introduction of next-generation sequencing into the diagnosis of neuromuscular disorders has resulted in an increased number of newly identified RYR1 variants. The hypothesis was that there is an increased referral of patients to malignant hyperthermia units without a personal/family history of adverse anesthetic events suspected to be malignant hyperthermia. This retrospective multicenter cohort study evaluates patient referral indications and outcomes for those without a history of an adverse anesthetic event. Patients referred between 2010 and 2019 to the malignant hyperthermia units in Antwerp, Belgium; Lund, Sweden; Nijmegen, The Netherlands; and Toronto, Ontario, Canada were included. Previously tested patients and relatives of previously tested patients were excluded. Data collection included demographics, referral details, muscle contracture, and genetic testing results including Rare Exome Variant Ensemble Learner scores. Referral indications were categorized into those with a personal/family history of adverse anesthetic event and other indications including exertional and/or recurrent rhabdomyolysis, RYR1 variant(s) detected in diagnostic testing in the neuromuscular clinic without a specific diagnosis (in a family member), diagnosed RYR1-related myopathy (in a family member), idiopathically elevated resting creatine kinase values, exertional heat stroke, and other. A total of 520 medical records were included, with the three most frequent referral indications as follows: personal history of an adverse anesthetic event (211 of 520; 40.6%), family history of an adverse anesthetic event (115 of 520; 22.1%), and exertional and/or recurrent rhabdomyolysis (46 of 520; 8.8%). The proportion of patients referred without a personal/family history of an adverse anesthetic event increased to 43.6% (133 of 305) between 2015 and 2019 compared to 28.4% (61 of 215) in 2010 to 2014 (P < 0.001). Patients with a personal/family history of an adverse anesthetic event were more frequently diagnosed as malignant hyperthermia-susceptible (133 of 220; 60.5%) than those without (47 of 120; 39.2%; P < 0.001). Due to missing data, 180 medical records were excluded. The proportion of patients referred to malignant hyperthermia units without a personal/family history of an adverse anesthetic event has increased, with 39.2% (47 of 120) diagnosed as malignant hyperthermia-susceptible.

Development and implementation of veterinary anesthesia medical quality standards for primary care

ObjectiveThe provision of general anesthesia is common in veterinary hospitals and procedures include some level of risk, up to and including mortality. A quality initiative was introduced with a focus on reducing canine and feline anesthesia mortality. This paper describes the development and implementation of risk-based medical quality standards (MQS) and resultant impacts on anesthesia mortality. Study designThis was a qualitative observational study. MQS focused on the provision of anesthesia were researched, developed and implemented. Anesthesia mortality rates, captured via an automated process based on the electronic medical record, were recorded before and after implementation. Compliance to standards was determined via hospital auditing. AnimalsClient-owned dogs and cats presenting to Banfield Pet Hospital (a national network of primary care hospitals) for elective and nonelective general anesthesia procedures. Over the course of the study, 2,038,318 dogs and 350,410 cats had a general anesthesia event. MethodsLiterature reviews and analysis of veterinary patient medical records identified risk factors associated with anesthesia mortality. Risk factors informed the development of MQS. Evidence-based standards focused on the provision of general anesthesia were written, reviewed, evaluated and edited. Implementation occurred over 6 months via a robust communication plan. Anesthesia mortality rates were continuously monitored before, during and after the introduction of standards. Compliance with all quality standards was assessed via hospital-based auditing performed on an annual basis. ResultsPrior to quality standards implementation, anesthesia mortality rates for dogs and cats combined was 7.4 deaths/10,000 procedures. At 6 months after implementation, the mortality rate was 6.24 deaths/10,000 procedures, representing a 16% decrease. Compliance with standards improved over time with continued focus and education. Conclusions and clinical relevanceDevelopment, implementation and continued focus on MQS can improve anesthetic safety and reduce anesthesia mortality in primary care veterinary hospitals.

The use of sugammadex in critical events in anaesthesia: A retrospective review of the webAIRS database

Sugammadex has been used for more than ten years in Australia and New Zealand and has been implicated as an effective treatment, and in some cases a potential cause, of a critical incident. We aimed to identify and analyse critical incidents involving sugammadex reported to webAIRS, a de-identified voluntary online critical incident reporting system in Australia and New Zealand. We identified 116 incidents where the reporter implicated sugammadex as either a cause (23 cases) or a treatment (93 cases) during anaesthesia. There were 17 incidents suggestive of sugammadex anaphylaxis, although not all were confirmed by skin testing. There were six incidents when bradycardia was temporally related to sugammadex administration, although it was not possible to exclude other causes or contributory factors. There were nine incidents in which sugammadex was used to reverse aminosteroid-related neuromuscular blockade successfully in a 'can't intubate, can't oxygenate' (CICO) situation, and a further 67 incidents in which sugammadex was used to reverse aminosteroid neuromuscular blockade as part of the management of other critical incidents. While sugammadex was used during the management of 16 cases of anaphylaxis, there was no clear indication that this altered the course of the anaphylaxis in any of the cases. These reports indicate that sugammadex can be a potential trigger for anaphylaxis and that its use may be associated with the development of significant bradycardia. However, it is not possible to estimate or even speculate on the incidence of these sugammadex-related incidents on the basis of voluntary reporting to a database such as webAIRS. The reports also indicate that sugammadex has been used successfully to reverse residual or deep aminosteroid neuromuscular blockade in critical incident situations and to help rescue CICO scenarios. These findings provide further support for ensuring the ready availability of sugammadex wherever aminosteroid muscle relaxants are used.

Effect of active forced air warming during the first hour after anesthesia induction and intraoperation avoids hypothermia in elderly patients

BackgroundThe study aimed at exploring an optimal temperature model of forced air warming during the first hour after induction and intraoperation to prevent hyperthermia for elderly patients undergoing laparoscopic abdominal surgery.MethodsThere were 218 patients that were randomly divided into 3 groups warmed with a forced-air warmer during surgery: Group L (intraoperative warming set to 38 °C, n = 63), Group H (intraoperative warming set to 42 °C, n = 65) and Group LH (intraoperative warming set to 42 °C for the first hour then set to 38 °C, n = 65). Core temperature in the preoperative room and PACU was measured by a tympanic membrane thermometer and in the operation room, a nasopharyngeal temperature probe was recorded. The rate of perioperative hypothermia, defined as a reduction in body temperature to < 36 °C was recorded as the primary outcome. Intraoperative anesthetic dosage, recovery time, adverse events, thermal comfort and satisfaction score were measured as secondary outcome.ResultsThe incidence of intraoperative and postoperative hypothermia was significantly lower in Group LH and Group H than Group L (18.75 and 15.62% vs 44.44%, P<0.001; 4.69 and 4.69% vs 20.63%, P<.05). Anesthetic dosage of rocuronium was lower in Group L than other two groups, with the opposite result of recovery time. The number of patients with shivering was higher in Group L but sweating was higher in Group H. Both of the thermal comfort and satisfaction score was highest in Group LH.ConclusionA temperature pattern of forced air warming set at 42 °C during the first hour after anesthesia induction and maintained with 38 °C was a suitable choice for elderly patients undergoing laparoscopic abdominal surgery lasting for more than 120 min.Trial registrationChictr.org.cn ChiCTR-2,100,053,211.

Type-1 Laryngeal Cleft and Pathogenic Bacterial Growth in the Lower Airway in Children.

The purpose of this study is to evaluate the association between type-1 laryngeal clefts and pathogenic bacterial growth in the lower airway in children. Retrospective chart review. A retrospective chart review was conducted for all children who underwent direct laryngoscopy, flexible bronchoscopy with bronchoalveolar lavage (BAL), and esophagogastroduodenoscopy, under a single anesthetic event from 2015 until 2018 at an academic tertiary referral center. Type-1 laryngeal clefts were diagnosed as an interarytenoid depth at or below the level of the vocal folds, on direct laryngoscopy, via palpation by a fellowship-trained pediatric otolaryngologist. Pathogenic bacterial growth in the lower airway was defined as presence of BAL culture growth of nonrespiratory flora. A total of 217 patients were identified. Type-1 laryngeal cleft was significantly associated with chronic cough (P= .0016) and cough with feeds (P< .0001). However, an abnormal video fluoroscopic swallow study was not found to be significantly associated with type-1 laryngeal cleft (P= .92) or pathogenic bacterial growth in the lower airway (P= 0.19). Overall, 122 (56%) patients were diagnosed with type-1 laryngeal cleft, 75 (35%) had pathogenic bacterial growth in the lower airway and 50 (23%) had both type-1 laryngeal cleft and pathogenic bacterial growth in the lower airway. Type-1 laryngeal cleft was significantly associated with pathogenic bacterial growth in the lower airway on both univariate analysis (P= .0307) and multivariate analysis (P= .0298, odds ratio 1.922, 95% confidence interval 1.066-3.467). Children with type-1 laryngeal clefts are at higher risk of having pathogenic bacterial growth in the lower airway. 4 Laryngoscope, 132:1825-1828, 2022.

Development and Internal Validation of the Postoperative Analgesic Intake Needs Score: A Predictive Model for Post-Operative Narcotic Requirement after Spine Surgery.

Retrospective Cohort. The aim of this study was to develop a clinical tool to pre-operatively risk-stratify patients undergoing spine surgery based on their likelihood to have high postoperative analgesic requirements. A total of 1199 consecutive patients undergoing elective spine surgery over a 2-year period at a single center were included. Patients not requiring inpatient admission, those who received epidural analgesia, those who had two surgeries at separate sites under one anesthesia event, and those with a length of stay greater than 10 days were excluded. The remaining 860 patients were divided into a derivation and validation cohort. Pre-operative factors were collected by review of the electronic medical record. Total postoperative inpatient opioid intake requirements were converted into morphine milligram equivalents to standardize postoperative analgesic requirements. The postoperative analgesic intake needs (PAIN) score was developed after the following predictor variables were identified: age, race, history of depression/anxiety, smoking status, active pre-operative benzodiazepine use and pre-operative opioid use, and surgical type. Patients were risk-stratified based on their score with the high-risk group being more likely to have high opioid consumption postoperatively compared to the moderate and low-risk groups in both the derivation and validation cohorts. The PAIN Score is a pre-operative clinical tool for patients undergoing spine surgery to risk stratify them based on their likelihood for high analgesic requirements. The information can be used to individualize a multi-modal analgesic regimen rather than utilizing a "one-size fits all" approach.

Frequently applied ketamine, medetomidine and thiopental anaesthesia induces high mortality in Wistar rats.

Fatal reactions to the combination of ketamine-medetomidine and thiopental in Wistar rats are described in two different models of orthodontic tooth movement. Thirty male rats were divided into two groups that required repeated anaesthesia during a 42-day study period, once a week or more frequently depending on the experimental group. The combination of ketamine [50 mg/kg body weight (b.w.)] and medetomidine (67 µg/kg b.w.) was administered intraperitoneally. Thiopental (8.3 mg/kg b.w.) was administered intraperitoneally 5 minutes later, barring any observable adverse reactions to the anaesthesia. Twelve animals died, though none during the first two procedures. Three animals died shortly after the administration of a ketamine-medetomidine combination, and the remainder died 10-25 minutes later. Only four of the affected animals received thiopental before their death on a particular day. As ten rats died in the more frequently anaesthetized group, repeated anaesthesia was suspected to be the cause of the increased mortality. Obstruction of the respiratory airways by saliva with subsequent suffocation may have been one of the causes of death, as it appeared in all the affected animals. Although the combination of ketamine and an alpha-2 adrenergic agonist is generally considered to be safe in rats, we propose that studies utilizing protocols requiring repeated anaesthesia adhere to a minimum safety period of 8.5 days between anaesthesia events. Alternative anaesthetic protocols should be employed if adherence to this is not possible due to the nature of the study.

Anesthesia-induced severe esophagitis in a cat

This case report describes the development of severe esophagitis after an anesthesia event for a shaving procedure in a seven years old male cat. The cat was brought to our animal clinic with a complaint of severe vomiting and appetite loss. It was reported that vomiting has started after the administration of xylazine-ketamine anesthesia for the shaving procedure. In the endoscopic examination, severe esophagitis has been detected. Within two weeks, esophagitis was complicated with megaesophagus and then severe weight loss had been observed. Post-treatment endoscopic examination couldn’t be performed because the esophagitis had developed after anesthesia. Regardless of whether a surgical procedure has been performed or the anesthesia has been performed repeatedly or once, post-anesthesia reflux esophagitis should also be suspected in cases of persistent appetite loss or dysphagia and vomiting after anesthesia.

Alterations of actin cytoskeleton and arterial protein level in patients with obstructive jaundice.

Vascular hypo-responsiveness to vasopressors in patients with obstructive jaundice (OJ) is a common anesthetic event, which leads to perioperative complications and increased mortality. The cause of this clinical issue remains unclear. In this study, we estimated the actin cytoskeleton and arterial protein level in the artery of OJ patients by proteomic analysis. Ten patients with OJ due to bile duct diseases or pancreatic head carcinoma were enrolled, while another ten non-jaundice patients with chronic cholecystitis or liver hemangioma as the control group. Vascular reactivity to noradrenaline was measured before anesthesia on the day of surgery. Artery samples in adjacent tissues of removed tumor were collected and evaluated by 2-dimensional electrophoresis. Proteins with differential expression were detected by MALDI-TOF mass spectrometry with immunoblot confirmation. The results confirmed the phenomenon of vascular hypo-reactivity in OJ patients as suppressed aortic response to noradrenaline were existed in these patients. We also found that actin cytoskeleton and several actin-binding proteins were up- or down-regulated in the artery of OJ patients. These proteins changed in OJ patents might be the basic mechanism of vascular hypo-reactivity, further studies to uncover the role of these proteins in OJ is critical for clinical treatment of these patients.

Simultaneous Gallbladder Carcinoma and Gist of the Stomach, a Rare Case of Multiple Primary Malignant Tumors: A Case Report

Background: Multiple primary malignant tumors are defined as two concurrent cancers from differing histologic origins. The presence of two concomitant malignancies raises challenges regarding treatment approach and coordination of neoadjuvant, surgical, and adjuvant therapies. The existing data and treatment approaches to multiple primary malignant tumors are limited. Methods: Review of an interesting case presentation. Results: In this case report, we present the case of a 76-year-old female who presented with a synchronous gastrointestinal stromal tumor of the stomach and gallbladder adenocarcinoma. She underwent diagnostic laparoscopy, Intra-op Ultrasound, laparoscopic gastric wedge resection of the lesser curvature GIST, and cholecystectomy with limited portal lymphadenectomy. The pathology report demonstrated a pT1bN0M0 well-differentiated papillary adenocarcinoma of the gallbladder, and a pT2pN0M0 low-grade gastrointestinal stromal tumor. Her case was presented at a multidisciplinary tumor board which ultimately recommended six months of adjuvant capecitabine. Her five-month follow up PET scan was negative for local recurrence or metastatic disease. Conclusion: There is currently limited literature regarding treatment approaches to multiple primary malignant tumors. As such, each case must be thoroughly discussed and reviewed. In this case report, the tumors were able to be resected within a single anesthesia event and single surgical field. Additionally, only one of the tumors merited adjuvant chemotherapy. Further investigation into multiple primary malignant tumors with conflicting treatment approaches will provide further insight into these rare and challenging cases. KeywordsGallbladder Carcinoma, Multiple Primary Malignant tumors, Gastrointestinal Stromal Tumor, GIST

Anaesthetic management of a dog with tetralogy of Fallot undergoing placement of a modified Blalock‐Taussig shunt

AbstractA 6‐month‐old male Old English Bulldog with tetralogy of Fallot (ToF) required general anaesthesia for surgical palliative treatment of ToF, whereby a shunt was placed between the left subclavian artery and the pulmonary trunk to increase pulmonary circulation (modified Blalock‐Taussig shunt). Anaesthesia of a patient with ToF presents an anaesthetic challenge given the four concurrent cardiac defects as well as the surgical manoeuvres involved, requiring an advanced understanding of the underlying pathophysiology and haemodynamics. Besides this, a thorough knowledge of the clinical effects of anaesthetic events and drugs is required. This case report describes the two major anaesthetic events that occurred and the unexplained hyperkalaemia that developed. Furthermore their management is explained and discussed.

Risk assessment and optimization strategies to reduce perioperative respiratory adverse events in Pediatric Anesthesia-Part 2: Anesthesia-related risk and treatment options.

Perioperative respiratory adverse events are the most common cause of critical events in children undergoing anesthesia and surgery. While many risk factors remain unmodifiable, there are numerous anesthetic management decisions which can impact the incidence and impact of these events, especially in at-risk children. Ongoing research continues to improve our understanding of both the influence of risk factors and the effect of specific interventions. This review discusses anesthesia risk factors and outlines strategies to reduce the rate and impact of perioperative respiratory adverse events with a chronologic based inquiry into anesthetic management decisions through the perioperative period from premedication to postoperative disposition.

Predicting anesthetic infusion events using machine learning

Recently, research has been conducted to automatically control anesthesia using machine learning, with the aim of alleviating the shortage of anesthesiologists. In this study, we address the problem of predicting decisions made by anesthesiologists during surgery using machine learning; specifically, we formulate a decision making problem by increasing the flow rate at each time point in the continuous administration of analgesic remifentanil as a supervised binary classification problem. The experiments were conducted to evaluate the prediction performance using six machine learning models: logistic regression, support vector machine, random forest, LightGBM, artificial neural network, and long short-term memory (LSTM), using 210 case data collected during actual surgeries. The results demonstrated that when predicting the future increase in flow rate of remifentanil after 1 min, the model using LSTM was able to predict with scores of 0.659 for sensitivity, 0.732 for specificity, and 0.753 for ROC-AUC; this demonstrates the potential to predict the decisions made by anesthesiologists using machine learning. Furthermore, we examined the importance and contribution of the features of each model using Shapley additive explanations—a method for interpreting predictions made by machine learning models. The trends indicated by the results were partially consistent with known clinical findings.

Remimazolam for induction of anesthesia in elderly patients with severe aortic stenosis: a prospective, observational pilot study

BackgroundRemimazolam, a novel benzodiazepine, has been reported to cause less hypotension than propofol during induction of anesthesia. Therefore, remimazolam might be a valuable option in elderly patients with severe aortic stenosis who are considered to be the most vulnerable to hemodynamic instability. We aimed to evaluate the feasibility and hemodynamic effects of remimazolam as an induction agent in elderly patients with severe aortic stenosis.MethodsThis prospective, open-label, single-arm, observational pilot study was conducted in a university hospital between November 2020 and April 2021. We included 20 patients aged 65 years or older scheduled for transcatheter or surgical aortic valve replacement for severe aortic stenosis under general anesthesia. Patients were administered intravenous remimazolam infusion at 6 mg/kg/h combined with 0.25 μg/kg/min of remifentanil infusion. The primary outcome was the vasopressor dosage between the induction of anesthesia and the completion of tracheal intubation. The secondary outcomes included hemodynamic changes, bispectral index changes, and the time from the start of remimazolam infusion to loss of consciousness. We also recorded awareness during anesthesia induction and serious adverse events related to death, life-threatening events, prolonged hospitalizations, and disability due to permanent damage.ResultsTwenty patients aged 84 [79–86] (median [interquartile range]) with American Society of Anesthesiologists physical status 4 were analyzed. Ephedrine 0 [0–4] mg and phenylephrine 0.1 [0–0.1] mg were administered to 14/20 patients (3 doses in 1 patient, 2 doses in 4 patients, and one dose in 9 patients). Loss of consciousness was achieved at 80 [69–86] s after the remimazolam infusion was started. The mean arterial pressure decreased gradually after loss of consciousness but recovered immediately after tracheal intubation. The bispectral index values gradually decreased and reached < 60 at 120 s after loss of consciousness. Neither awareness during induction of anesthesia nor serious adverse events, such as severe bradycardia (< 40 bpm), life-threatening arrhythmia, myocardial ischemia, or anaphylactic reactions were observed.ConclusionsRemimazolam could be used as an induction agent with timely bolus vasopressors in elderly patients with severe aortic stenosis.Trial registrationUMIN Clinical Trials Registry, identifier UMIN000042318.

Manual Anesthesia Record Keeping at a Tertiary Care Center: A Descriptive Cross-sectional Study.

Intraoperative record form is one of the cardinal parts of anesthesia practices. Ideally, it should contain complete information about patients under anesthesia and intraoperative events. It serves as valuable information for subsequent patient management, research, or during medicolegal conditions. The objective of this study was to assess the practice and completeness of manual intraoperative anesthesia record keeping. A descriptive cross-sectional study was conducted from May 1 to July 31, 2021, in the postoperative ward of Kathmandu Medical College, which is a multispecialty tertiary care center. Approval from the ethical committee of Kathmandu Medical College Teaching Hospital was obtained (Reference: 2603202105) before conducting the study. Convenience sampling was used. The data were entered in Microsoft Excel and statistical analysis was done using Statistical Package for the Social Sciences version 20. Point estimate was done at 95% Confidence Interval and data present in numbers and percentages. We devised forty-two variables, which included demographics, personal identifiers, intraoperative events, anesthesia and airway management, intraoperative parameters, monitoring and medication. The overall completion rate was 202 (52.59%) (47.6-57.57 at 95% Confidence Interval). Out of 42 variables, the completion rate of 14 variables was less than 50%. Among those were important parameters such as known allergies 94 (24.4%), Body mass index 50 (13%), intraoperative saturation of oxygen 104 (27%), intraoperative electrocardiogram recording 107 (27.8%), total fluid volume administered 45 (11.7%), patient status on transfer 84 (21.8%) had poor completion rate. Our intraoperative record form shows poor completion rate, which was similar to other studies. many important variables were missing and had incomplete data.

Simulation Technology in Anesthesiology.

Simulation Technology in Anesthesiology.