Apneustic anesthesia ventilation improves pulmonary function in anesthetized bottlenose dolphins (Tursiops truncatus).

Introduction: Use of mechanical ventilation during general anesthesia is a necessary practice in the anesthetization of small cetaceans as spontaneous ventilation fails to provide adequate gas exchange. Currently available methods of ventilation do not account for the intermittent breathing strategy of representative species within this infraorder of fully aquatic mammals and may have a significant effect on cardiac and respiratory physiology. Methods: To understand the impact of mechanical ventilation on cardiopulmonary function in one small species of cetacean, the bottlenose dolphin (Tursiops truncatus), we compared controlled mechanical ventilation (CMV) to a novel ventilation method known as apneustic anesthesia ventilation (AAV). AAV simulates the normal inspiratory breath-hold pattern of dolphins. Ten anesthetic procedures (dental procedure, n = 9; bronchoscopy, n = 2) were performed on nine dolphins (age range: 10-42 years; mean = 32 years; median = 37 years; female = 3, 40%; male = 6, 60%). In a cross-over study design, dolphins were instrumented and randomly assigned to AAV or CMV as the initial mode of ventilation, then switched to the alternate mode. Baseline cardiopulmonary data were collected and again after 30 min on each mode of ventilation. Cardiac index, stroke volume index, systemic vascular resistance, alveolar dead space, alveolar-arterial oxygen tension gradient, arterial oxygen content, oxygen delivery index, and dynamic respiratory system compliance index were calculated at each of the four time points. Results: During AAV, dolphins had higher arterial oxygen tension, higher mean airway pressure, reduced alveolar dead space ventilation and lower alveolar-arterial oxygen difference. Cardiovascular performance was not statistically different between the two modes. Discussion: Our study suggests AAV, which more closely resembles the conscious intermittent respiratory pattern phenotype of dolphins, improves ventilation and pulmonary function in the anesthetized dolphin. Future studies should evaluate the cardiopulmonary effects of neutral buoyancy and cardiopulmonary sparing drug protocols to reduce the need for hemodynamic support of current protocols.

American society of anesthesiologists physical status classification significantly affects the performances of machine learning models in intraoperative hypotension inference.

STUDY OBJECTIVE: To explore how American Society of Anesthesiologists (ASA) physical status classification affects different machine learning models in hypotension prediction and whether the prediction uncertainty could be quantified. DESIGN: Observational Studies SETTING: UofL health hospital PATIENTS: This study involved 562 hysterectomy surgeries performed on patients (≥ 18 years) between June 2020 and July 2021. INTERVENTIONS: None MEASUREMENTS: Preoperative and intraoperative data is collected. Three parametric machine learning models, including Bayesian generalized linear model (BGLM), Bayesian neural network (BNN), a newly proposed BNN with multivariate mixed responses (BNNMR), and one nonparametric model, Gaussian Process (GP), were explored to predict patients' diastolic and systolic blood pressures (continuous responses) and patients' hypotensive event (binary response) for the next five minutes. Data was separated into American Society of Anesthesiologists (ASA) physical status class 1- 4 before being read in by four machine learning models. Statistical analysis and models' constructions are performed in Python. Sensitivity, specificity, and the confidence/credible intervals were used to evaluate the prediction performance of each model for each ASA physical status class. MAIN RESULTS: ASA physical status classes require distinct models to accurately predict intraoperative blood pressures and hypotensive events. Overall, high sensitivity (above 0.85) and low uncertainty can be achieved by all models for ASA class 4 patients. In contrast, models trained without controlling ASA classes yielded lower sensitivity (below 0.5) and larger uncertainty. Particularly, in terms of predicting binary hypotensive event, for ASA physical status class 1, BNNMR yields the highest sensitivity of 1. For classes 2 and 3, BNN has the highest sensitivity of 0.429 and 0.415, respectively. For class 4, BNNMR and GP are tied with the highest sensitivity of 0.857. On the other hand, the sensitivity is just 0.031, 0.429, 0.165 and 0.305 for BNNMR, BNN, GBLM and GP models respectively, when training data is not divided by ASA physical status classes. In terms of predicting systolic blood pressure, the GP regression yields the lowest root mean squared errors (RMSE) of 2.072, 7.539, 9.214 and 0.295 for ASA physical status classes 1, 2, 3 and 4, respectively, but a RMSE of 126.894 if model is trained without controlling the ASA physical status class. The RMSEs for other models are far higher. RMSEs are 2.175, 13.861, 17.560 and 22.426 for classes 1, 2, 3 and 4 respectively for the BGLM. In terms of predicting diastolic blood pressure, the GP regression yields the lowest RMSEs of 2.152, 6.573, 5.371 and 0.831 for ASA physical status classes 1, 2, 3 and 4, respectively; RMSE of 8.084 if model is trained without controlling the ASA physical status class. The RMSEs for other models are far higher. Finally, in terms of the width of the 95% confidence interval of the mean prediction for systolic and diastolic blood pressures, GP regression gives narrower confidence interval with much smaller margin of error across all four ASA physical status classes. CONCLUSIONS: Different ASA physical status classes present different data distributions, and thus calls for distinct machine learning models to improve prediction accuracy and reduce predictive uncertainty. Uncertainty quantification enabled by Bayesian inference provides valuable information for clinicians as an additional metric to evaluate performance of machine learning models for medical decision making.

Lung Ultrasound Abnormalities in Patients Without Pulmonary Pathology Prior to Surgery.

Background: The occurrence of lung ultrasound abnormalities in patients without lung disease remains uncertain, while patients with respiratory disease often exhibit such abnormalities. Objectives: The primary aim was to identify pathological ultrasonographic pulmonary findings and their correlation with baseline diseases and static lung compliance in patients without any pre-existing respiratory conditions. Methods: This prospective observational study enrolled a series of surgical patients with no history of pulmonary pathology (n = 104). Baseline diseases and patients' physical status classification, based on the American Society of Anesthesiologists (ASA), were documented by reviewing medical records. Prior to surgery, a lung ultrasound was performed to assess pulmonary changes. During surgery with general anesthesia, static lung compliance was measured. The Spearman correlation coefficient was employed to determine the correlation between the two variables. Results: Twenty-four patients (23.07%) exhibited 1 - 2 B-lines in certain lung fields. Seven patients (6.7%) had an ultrasound B-line score > 0 (indicating ≥ 3 B-lines). Among these patients, the average number of lung fields with ≥ 3 B-lines was 3.71 ± 2.43. Patients with systemic diseases (ASA ≥ 2) displayed a higher number of B-lines compared to ASA I patients (P-value = 0.039). Pleural irregularities were found in 10 patients (9.6%), while atelectasis and pleural effusion were observed in five (4.8%) and four (3.8%) patients, respectively. The mean lung compliance value was 56.78 ± 15.33. No correlation was observed between the total score of the B-lines and lung compliance (Spearman's correlation: rho = -0.028, P-value = 0.812). Conclusions: Patients without pulmonary pathology may exhibit ultrasound pulmonary abnormalities, which tend to increase with higher ASA scores and do not appear to have a correlation with static lung compliance.

Non-surgical patient characteristics best predict outcome after 6 months in patients surgically treated for chronic subdural haematoma.

BACKGROUND: Chronic subdural haematoma (CSDH) is one of the most common conditions encountered in neurosurgical practice. After surgery, the patients often improve dramatically; but their long-term outcome is more uncertain. The purpose of this study was to investigate predictors of outcome 6 months after surgery. METHODS: Retrospective data were collected on patients in Orebro County, Sweden, who had undergone surgery for CSDH at the Orebro University Hospital between 2013 and 2019. The outcomes were defined as favourable or unfavourable in terms of the modified Rankin Scale (mRS). A favourable outcome was defined as either mRS 0-2 or an unchanged mRS score in patients scoring 3-5 before surgery. From the variables in the data collected, a multiple logistic regression model was constructed. RESULTS: The study comprised 180 patients, of whom 134 (74.4%) were male. Median age was 79.2 years (IQR 71.7-85.5), and 129 (71.7%) patients had a favourable outcome at 6 months. In the group with an unfavourable outcome, 18 (10%) had died and 33 (18.3%) had either lost their independence in daily living or become somewhat less independent. The final multiple logistic regression model consisted of pre-surgery variables only: age (OR 0.92, 95% CI 0.87-0.97), CRP (OR 0.96, 95% CI 0.94-0.99), GCS > 13 (OR 3.66, 95% CI 1.09-12.3), Hb (OR 1.03, 95% CI 1.00-1.05), and ASA score < 3 (OR 2.58, 95% CI 0.98-6.79). The whole model had an AUC of 0.88. CONCLUSION: CSDH requiring surgery is associated with high morbidity and mortality at 6 months after surgery. Age, CRP, GCS, Hb and ASA score on admission for surgery are the variables that best predicts outcome. This knowledge can help to identify the patients at greatest risk for an unfavourable outcome, who may need additional support from the health care system. UNSTRUCTURED ABSTRACT: Chronic subdural haematoma (CSDH) is one of the most common conditions encountered in neurosurgical practice. After surgery, the patients often improve dramatically; but their long-term outcome is more uncertain. The purpose of this study was to investigate predictors of outcome, in terms of the modified Rankin Scale (mRS), 6 months after surgery. The study comprised 180 patients, of whom 134 (74.4%) were male. Median age was 79.2 years (IQR 71.7-85.5), and 129 (71.7%) patients had a favourable outcome at 6 months. In the group with an unfavourable outcome, 18 (10%) had died and 33 (18.3%) had either lost their independence in daily living or become somewhat less independent. The final multiple logistic regression model consisted of pre-surgery variables only: age (OR 0.92, 95% CI 0.87-0.97), CRP (OR 0.96, 95% CI 0.94-0.99), GCS > 13 (OR 3.66, 95% CI 1.09-12.3), Hb (OR 1.03, 95% CI 1.00-1.05), and ASA score < 3 (OR 2.58, 95% CI 0.98-6.79). The whole model had an AUC of 0.88. In conclusion, CSDH requiring surgery is associated with high morbidity and mortality at 6 months after surgery. Age, CRP, GCS, Hb and ASA score on admission for surgery are the variables that best predicts outcome. This knowledge can help to identify the patients at greatest risk for an unfavourable outcome, who may need additional support from the health care system.

Urgent versus elective laparoscopic cholecystectomy following percutaneous transhepatic gallbladder drainage for high-risk grade II acute cholecystitis.

BACKGROUND: The aim of this study was to evaluate the safety of urgent laparoscopic cholecystectomy (Lap-C) for grade II acute cholecystitis (AC) in high-risk patients who were defined by Tokyo Guideline 18 as having age-adjusted Charlson comorbidity index ≥6 or American Society of Anesthesiologists physical status classification (ASA-PS) ≥ 3, compared with elective Lap-C following percutaneous transhepatic gallbladder drainage (PTGBD). METHODS: In 73 grade II AC patients who underwent Lap-C from January 2012 to March 2021, 35 were identified as high-risk; 22 underwent urgent Lap-C (urgent group) and 13 PTGBD followed by elective Lap-C (elective group). Surgical and perioperative outcomes were analyzed. RESULTS: There was no significant difference in operation time (median: 101 min vs 125 min; P = 0.371), blood loss (25 ml vs 7 ml; P = 0.853), morbidity rate (31.8% vs 38.5%; P = 0.726), or the incidence of total perioperative major complications (13.6% vs 15.4%; P = 1.000) between the two groups. The total duration of treatment was significantly shorter in the urgent group than the elective group (11 days vs 71 days; P < 0.001). Multivariate analysis revealed that blood loss ≥45 ml [odds ratio (OS): 12.14, 95% confidence interval (CI): 2.03-72.42, P = 0.006], and age ≥75 years with ASA-PS ≥ 3 (OS: 9.85, 95%CI: 1.26-77.26, P = 0.03) were the independent risk factors for total perioperative major complications. CONCLUSION: In well-selected high-risk patients with grade II AC, urgent Lap-C can be performed with comparable safety to elective Lap-C following PTGBD.

Effect of the preoperative physical status on postoperative nausea and vomiting risk: a matched cohort study.

BACKGROUND: The American Society of Anesthesiologists Physical Status Classification System is commonly used for preoperative assessment. Patient physical status before surgery can play an important role in postoperative nausea and vomiting. However, the relationship between the physical status classification and postoperative nausea and vomiting has not been well defined. METHODS: Adults aged ≥ 18 years who underwent procedures under anesthesia between 2015 and 2020 were included in the study. We analyzed the relationship of postoperative nausea and vomiting with physical status classification score using propensity score matching and Cox hazard regression. Differences in intraoperative use of vasopressor and inotropes and invasive monitoring were investigated according to the classification. RESULTS: A total of 163,500 patients were included in the study. After matching, classification 1 versus 2 included 43,400 patients; 1 versus ≤ 3, 13,287 patients; 2 versus ≤ 3, 23,530 patients (absolute standardized difference, 0-0.06). Patients with physical status classification ≤ 3 had a significantly lower postoperative nausea and vomiting risk than those with classification 1-2 (physical status classification 1 vs. ≤ 3, hazard ratio 0.76 [0.71-0.82], P < 0.001; 2 versus ≤ 3, hazard ratio 0.86 [0.82-0.91], P < 0.001). Intraoperative use of vasopressor or inotrope and invasive monitoring were noted more in the high physical status classification than the low physical status classification (absolute standardized difference [0.19-1.25]). CONCLUSION: There were differences in intraoperative invasive monitoring and use of vasopressor or inotrope among the classifications, and a score of 3 or higher reduced the risk of postoperative nausea and vomiting more than a score of 1-2.

The impact of the American Society of Anesthesiology-Physical Status classification system on the treatment and prognosis of patients with esophageal cancer undergoing esophagectomy.

BACKGROUND: The American Society of Anesthesiologists-Physical Status (ASA-PS) classification system has been shown to predict morbidity and mortality after surgery. However, the impact of the ASA-PS on esophageal cancer treatment remains unclear. This study examined both the impact of the ASA-PS on treatment, including surgery and perioperative chemotherapy, and the prognostic effects of ASA-PS class in patients who had undergone esophagectomy for thoracic esophageal cancer or esophagogastric junction cancer. METHODS: ASA-PS status was collected for 301 patients who had undergone esophagectomy between January 2007 and June 2016 for thoracic esophageal cancer or esophagogastric junction cancer at a single institution. As the ASA-PS was updated in 2014, the previous classifications of all patients were reevaluated using the updated standard by a surgeon with the previous classifications masked. The dose intensity of preoperative chemotherapy was also compared across classes. Multivariate Cox regression analysis was used to analyze the association between ASA-PS class and overall survival. RESULTS: Patients whose reevaluations had placed them in a more severe ASA-PS class showed significantly poorer overall and cancer-specific survival rates. The dose intensities of cisplatin and 5-fluorouracil for preoperative chemotherapy were significantly lower in patients in the more severe ASA-PS classes. Multivariate analysis showed that ASA-PS class was an independent prognostic factor for overall survival. CONCLUSION: Preoperative ASA-PS classification may influence the intensity of perioperative treatment and may be a valuable long-term prognostic factor for patients with esophageal cancer undergoing esophagectomy.

Surgical Procedures in Patients Awaiting Liver Transplantation: Complications and Impact on the Liver Function.

BACKGROUND: Potential indications for surgery frequently arise in patients awaiting liver transplantation. There is a risk of hepatic decompensation and death triggered by surgical trauma, but this has not been studied in detail in this unique population. We aimed to quantify the impact of surgical interventions in patients awaiting liver transplantation on hepatic function and identify risk factors for decompensation. METHODS: All surgeries between 2000 and 2018 in patients awaiting liver transplantation in a highvolume German liver transplant center were analyzed retrospectively. Change in liver function measured as indicated by MELD score was assessed and complication rates recorded. The primary endpoint was a composite of an increase in MELD score by > 5 points or death. A logistic regression model was used for multivariate analysis to identify risk factors. RESULTS: In total, 177 surgical procedures in 148 patients were analyzed. The primary endpoint was reached in 42 cases (23.7%). The overall in-hospital complication rate (including death) was 44.1%. Multivariate analysis identified elevated leukocyte count, perioperative blood transfusion, preoperative presence of ascites, and preoperative circulatory support as independent risk factors for a decline in liver function or death. CONCLUSION: Surgery in patients awaiting liver transplantation carries a relevant risk of hepatic decompensation and death that needs to be considered when deciding whether to perform elective surgery prior to or defer until after liver transplantation.

Improving agreement of ASA physical status class between pre-anesthesia screening and day of surgery by adding institutional-specific and ASA-approved examples: a quality improvement project.

BACKGROUND: A successful anesthesia pre-assessment clinic needs to identify patients who need further testing, evaluation, and optimization prior to the day of surgery to avoid delays and cancelations. Although the ASA Physical Status Classification system (ASA PS) has been used widely for over 50 years, it has poor interrater agreement when only using the definitions. In 2014, ASA-approved examples for each ASA physical status class (ASA PS). In this quality improvement study, we developed and evaluated the effectiveness of institutional-specific examples on interrater reliability between anesthesia pre-anesthesia clinic (APAC) and the day of surgery evaluation (DOS). METHODS: A multi-step, multi-year quality improvement project was performed. Step 1, pre-intervention, was a retrospective review to determine the percentage agreement of ASA PS assignment between APAC and DOS for adult and pediatric patients. Step 2 was a retrospective review of the step 1 cases where the ASA PS assignment differed to determine which medical conditions were valued differently and then develop institutional-specific examples for medical conditions not addressed by ASA-approved examples. Step 3 was to educate clinicians about the newly implemented examples and how they should be used as a guide. Step 4, post-intervention, was a retrospective review to determine if the examples improved agreement between APAC and DOS ASA PS assignments. Weighted Kappa coefficient was used to measure of interrater agreement excluding chance agreement. RESULTS: Having only ASA PS definitions available, APAC and DOS agreement was only 74% for adults (n = 737) and 63% for pediatric patients (n = 216). For adults, 20 medical co-morbidity categories and, for pediatric patients, 9 medical co-morbidity categories accounted for > 90% the differences in ASA PS. After development and implementation of institutional-specific examples with ASA-approved examples, the percentage agreement increased for adult patients (n = 795) to 91% and for pediatric patients (n = 239) to 84%. Weighted Kappa coefficients increased significantly for all patients (from 0.62 to 0.85, p < .0001), adult patients (from 0.62 to 0.86, p < .0001), and pediatric patients (from 0.48 to 0.78, p < .0001). CONCLUSIONS: ASA-approved examples do not address all medical conditions that account for differences in the assignment of ASA PS between pre-anesthesia screening and day of anesthesia evaluation at our institution. The process of developing institutional-specific examples addressed the medical conditions that caused differences in assignment at one institution. The implementation of ASA PS examples improved consistency of assignment, and therefore communication of medical conditions of patients presenting for anesthesia care.

Lateral lumbar interbody fusion in revision surgery for restenosis after posterior decompression.

OBJECTIVE: The purpose of this study was to compare the clinical results of revision interbody fusion surgery between lateral lumbar interbody fusion (LLIF) and posterior lumbar interbody fusion (PLIF) or transforaminal lumbar interbody fusion (TLIF) with propensity score (PS) adjustments and to investigate the efficacy of indirect decompression with LLIF in previously decompressed segments on the basis of radiological assessment. METHODS: A retrospective study of patients who underwent revision surgery for recurrence of neurological symptoms after posterior decompression surgery was performed. Postoperative complications and operative factors were evaluated and compared between LLIF and PLIF/TLIF. Moreover, postoperative improvement in cross-sectional areas (CSAs) in the spinal canal and intervertebral foramen was evaluated in LLIF cases. RESULTS: A total of 56 patients (21 and 35 cases of LLIF and PLIF/TLIF, respectively) were included. In the univariate analysis, the LLIF group had significantly more endplate injuries (p = 0.03) and neurological deficits (p = 0.042), whereas the PLIF/TLIF group demonstrated significantly more dural tears (p < 0.001), surgical site infections (SSIs) (p = 0.02), and estimated blood loss (EBL) (p < 0.001). After PS adjustments, the LLIF group still showed significantly more endplate injuries (p = 0.03), and the PLIF/TLIF group demonstrated significantly more dural tears (p < 0.001), EBL (p < 0.001), and operating time (p = 0.04). The PLIF/TLIF group showed a trend toward a higher incidence of SSI (p = 0.10). There was no statistically significant difference regarding improvement in the Japanese Orthopaedic Association scores between the 2 surgical procedures (p = 0.77). The CSAs in the spinal canal and foramen were both significantly improved (p < 0.001). CONCLUSIONS: LLIF is a safe, effective, and less invasive procedure with acceptable complication rates for revision surgery for previously decompressed segments. Therefore, LLIF can be an alternative to PLIF/TLIF for restenosis after posterior decompression surgery.

Complication Rates and the Benefits of Neuraxial Anesthesia in the Patient With High Comorbidity Burden Undergoing Primary Total Joint Arthroplasty.

BACKGROUND: The American Society of Anesthesiologists physical status classification 4 (ASA PS 4) comprises patients with "severe systemic disease that is a constant threat to life." The purpose of this study is to conduct a retrospective analysis to report the rate of complications in the ASA PS 4 patients who undergo elective total joint arthroplasty (TJA). In addition, we report whether neuraxial anesthesia is associated with improved outcomes compared to general anesthesia in these patients. METHODS: The American College of Surgeons National Surgical Quality Improvement Program registry was used to extract patient records. The study population included patients aged ≥18 years who underwent TJA from 2014 to 2016 and who were classified as ASA PS 4. To measure differences in outcomes and patient characteristics, we used chi-squared tests. Odds ratios (ORs) and their 95% confidence intervals (CIs) were reported for all covariates. A P value of <.01 was selected. RESULTS: Among the patients who were ASA PS 4, 58 (1.4%) experienced 30-day mortality, 349 (8.2%) experienced 30-day readmission, 271 (6.3%) had a postoperative complication, and 504 (11.8%) required a transfusion. Those receiving neuraxial anesthesia compared to general anesthesia had lower odds of 30-day mortality (OR, 0.24; 95% CI, 0.12-0.49; P = .0001) and lower odds of perioperative transfusion (OR, 0.53; 95% CI 0.45-0.65; P < .0001). CONCLUSION: The elevated risks for ASA PS 4 patients undergoing TJA may be too high to justify surgery. Neuraxial anesthesia is a reasonable alternative to general anesthesia if pursuing TJA in patients with a very high comorbidity burden.

Predictive ability of the American Society of Anaesthesiologists physical status classification system on health-related quality of life of patients after total hip replacement: comparisons across eight EQ-5D-3L value sets.

BACKGROUND: American Society of Anaesthesiologists (ASA) physical status classification system and its association with postoperative outcomes has been studied in different diseases. However, there is a paucity of studies on the relationship between ASA class and postoperative health-related quality of life (HRQoL) outcomes following total hip replacement (THR). The aim of this study was to assess the discriminative abilities of EQ-5D-3L value sets from Sweden, Germany, Denmark and the United Kingdom in relation to ASA classes and these value sets' abilities to show the predictive performance of ASA classes on HRQoL among THR patients in Sweden. METHODS: A longitudinal study was conducted using data of patients in the Swedish Hip Arthroplasty Register who underwent THR between 2008 and 2016. We included 69,290 pre- and 1-year postoperative records and 21,305 6-year postoperative records. The study examined three experience-based EQ-5D-3L value sets (the Swedish VAS and TTO and the German VAS) and five hypothetical value sets (TTO from Germany and VAS and TTO value sets from Denmark and the UK each). Using linear models, the abilities of the value sets to discriminate among ASA classes and to show the predictive performance of ASA classes on HRQoL score were assessed. RESULTS: All value sets differentiated among ASA classes and showed the predictive effect of ASA classes on HRQoL. ASA classes were found to predict HRQoL consistently for all value sets investigated, with small variations in prediction error among the models. CONCLUSION: ASA classes of patients undergoing THR predicted HRQoL scores significantly and consistently, indicating their importance in tailoring care for patients.

Cost-effectiveness of minimally invasive midline lumbar interbody fusion versus traditional open transforaminal lumbar interbody fusion.

OBJECTIVE: The midline transforaminal lumbar interbody fusion (MIDLIF) using cortical screw fixation is a novel, minimally invasive procedure that may offer enhanced recovery over traditional open transforaminal lumbar interbody fusion (TLIF). Little information is available regarding the comparative cost-effectiveness of the MIDLIF over conventional TLIF. The purpose of this study was to compare cost-effectiveness of minimally invasive MIDLIF with open TLIF. METHODS: From a prospective, multisurgeon, surgical database, a consecutive series of patients undergoing 1- or 2-level MIDLIF for degenerative lumbar conditions was identified and propensity matched to patients undergoing TLIF based on age, sex, smoking status, BMI, diagnosis, American Society of Anesthesiologists Physical Status Classification System (ASA) class, and levels fused. Direct costs at 1 year were collected, including costs associated with the index surgical visit as well as costs associated with readmission. Improvement in health-related quality of life was measured using EQ-5D and SF-6D. RESULTS: Of 214 and 181 patients undergoing MIDLIF and TLIF, respectively, 33 cases in each cohort were successfully propensity matched. Consistent with propensity matching, there was no difference in age, sex, BMI, diagnosis, ASA class, smoking status, or levels fused. Spondylolisthesis was the most common indication for surgery in both cohorts. Variable direct costs at 1 year were $2493 lower in the MIDLIF group than in the open TLIF group (mean $15,867 vs $17,612, p = 0.073). There was no difference in implant (p = 0.193) or biologics (p = 0.145) cost, but blood utilization (p = 0.015), operating room supplies (p < 0.001), hospital room and board (p < 0.001), pharmacy (p = 0.010), laboratory (p = 0.004), and physical therapy (p = 0.009) costs were all significantly lower in the MIDLIF group. Additionally, the mean length of stay was decreased for MIDLIF as well (3.21 vs 4.02 days, p = 0.05). The EQ-5D gain at 1 year was 0.156 for MIDLIF and 0.141 for open TLIF (p = 0.821). The SF-6D gain at 1 year was 0.071 for MIDLIF and 0.057 for open TLIF (p = 0.551). CONCLUSIONS: Compared with patients undergoing traditional open TLIF, those undergoing MIDLIF have similar 1-year gains in health-related quality of life, with total direct costs that are $2493 lower. Although the findings were not statistically significant, minimally invasive MIDLIF showed improved cost-effectiveness at 1 year compared with open TLIF.

Four questions to identify patients with ASA III or higher.

BACKGROUND: Increased age, obesity, and American Society of Anesthesiologists (ASA) Physical Status class III and IV have been reported as predictors for mortality and perioperative complications. High-volume institutions rely on central referral services as first contact point for patients. The current study reports on a simple four-step questionnaire to identify patients with ASA-physical status class III and IV to improve referral processes and optimize perioperative work ups. MATERIALS AND METHODS: Seven hundred and seventy-five patients who called the physician referral service (PRS) at the author's institution and subsequently underwent surgery were enrolled in this study. The answers to the initial PRS questionnaire were analyzed. The study cohort consisted of 414 women (53.4%) and 361 men (46.6%) with an average age of 61.4 years (range 44-90 years) at the time of surgery. RESULTS: Binary logistic regression revealed hypertension, diabetes mellitus (using medication), using blood thinner (other than Aspirin) and a number of 4-9 prescribed medication, respectively, as predictors for ASA III and IV. Receiver-operating characteristic (ROC) curve analysis identified a sensitivity of 82.4%, a specificity of 82.9%, and an accuracy of 82.8%, when two of these four questions are answered "yes". The area under the curve for this analysis was 0.876 [95% confidence interval (CI) 0.845-0.908]. Positive and negative likelihood ratios were 4.8 (95% CI 4.0-5.8) and 0.2 (95% CI 0.1-0.3), respectively. CONCLUSIONS: This study revealed a simple four-step questionnaire to identify patients with ASA III or IV before a medical appointment. This helps to balance referrals between multiple providers in high-volume medical groups.

The effect of ICP monitoring in severe traumatic brain injury: a propensity score-weighted and adjusted regression approach.

OBJECTIVE: The use of intracranial pressure (ICP) monitoring has been postulated to be beneficial in patients with severe traumatic brain injury (TBI), although studies investigating this hypothesis have reported conflicting results. The objective of this study was to evaluate the effect of inserting an ICP monitor on survival in patients with severe TBI. METHODS: The Oslo University Hospital trauma registry was searched for the records of all patients admitted between January 1, 2002, and December 31, 2013, who fulfilled the Brain Trauma Foundation criteria for intracranial hypertension and who survived at least 24 hours after admission. The impact of ICP monitoring was investigated using both a logistic regression model and a multiple imputed, propensity score-weighted logistic regression analysis. RESULTS: The study involved 1327 patients, in which 757 patients had an ICP monitor implanted. The use of ICP monitors significantly increased in the study period (p < 0.01). The 30-day overall mortality was 24.3% (322 patients), divided into 35.1% (200 patients, 95% confidence interval [CI] 31.3%-39.1%) in the group without an ICP monitor and 16.1% (122 patients, 95% CI 13.6%-18.9%) in the group with an ICP monitor. The impact of ICP monitors on 30-day mortality was found to be beneficial both in the complete case analysis logistic regression model (odds ratio [OR] 0.23, 95% CI 0.16-0.33) and in the adjusted, aggregated, propensity score-weighted imputed data sets (OR 0.22, 95% CI 0.15-0.35; both p < 0.001). The sensitivity analysis indicated that the findings are robust to unmeasured confounders. CONCLUSIONS: The authors found that the use of an ICP monitor is significantly associated with improved survival in patients with severe head injury.

Impact of the ASA Physical Status Score on Adjuvant Chemotherapy Eligibility and Survival of Upper Tract Urothelial Carcinoma Patients: a Multicenter Study.

The aim of the present multi-institutional study was to assess the influence of the American Society of Anesthesiologists Physical Status (ASA-PS) classification on adjuvant chemotherapy eligibility and survival in a multi-institutional cohort of patients treated with radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC). We retrospectively reviewed data from 416 patients who underwent RNU for UTUC at four Korean institutions between 2001 and 2013. The ASA-PS classification was obtained from the anesthesia chart. Locally advanced UTUC was defined as ≥ pT3 and/or pN1 disease. The influence of ASA-PS score on survival was evaluated by Kaplan-Meier analyses and a multivariate Cox regression model. Patients with a higher ASA-PS class were less likely to be eligible for adjuvant chemotherapy in locally advanced UTUC (P = 0.016). Kaplan-Meier estimates showed that the high-risk ASA-PS group has a poorer overallsurvival (OS) and cancer-specific survival (CSS) compared to low risk ASA-PS groups in both the total and locally advanced UTUC cohorts. Based on multivariate Cox regression analysis, the high-risk ASA-PS category was an independent predictor for overall mortality (OM) (hazard ratio [HR], 1.919; 95% confidence interval [CI], 1.017-3.619; P = 0.044) and cancer-specific mortality (CSM) (HR, 2.120; 95% CI, 1.023-4.394; P = 0.043). In conclusion, high-risk ASA-PS score was independently associated with a lower survival rate in patients with UTUC after RNU. However, the influence of ASA-PS classification on survival was limited to locally advanced UTUC. The lower eligibility of patients in the high-risk ASA category for adjuvant chemotherapy may contribute to the lower survival rate in this group.

New surgical scoring system to predict postoperative mortality.

PURPOSE: There is still no easy and highly useful method to comprehensively assess both preoperative and intraoperative patient statuses to predict postoperative outcomes. We attempted to develop a new scoring system that would enable a comprehensive assessment of preoperative and intraoperative patient statuses instantly at the end of anesthesia, predicting postoperative mortality. METHODS: The study included 32,555 patients who underwent surgery under general or regional anesthesia from 2008 to 2012. From the anesthesia records, extracted factors, including patient characteristics and American Society of Anesthesiologists physical status classification (ASA-PS), and three intraoperative indexes (the lowest heart rate, lowest mean arterial pressure, and estimated volume of blood loss) are used to calculate the surgical Apgar score (sAs). The sAs and ASA-PS, and surgical Apgar score combined with American Society of Anesthesiologists physical status classification (SASA), which combines the sAs and ASA-PS into a single adjusted scale, were compared and analyzed with postoperative 30-day mortality. RESULTS: Increased severity of the sAs, ASA-PS and SASA was correlated with significantly higher mortality. The risk of death was elevated by 3.65 for every 2-point decrease in the sAs, by 6.4 for every 1-point increase in the ASA-PS, and by 9.56 for every 4-point decrease in the SASA. The ROC curves of the sAs and ASA-PS alone also individually demonstrated high validity (AUC = 0.81 for sAs and 0.79 for ASA-PS, P < 0.001). The SASA was even more valid (AUC = 0.87, P < 0.001). CONCLUSIONS: The sAs and ASA-PS were shown to be extremely useful for predicting 30-day mortality after surgery. An even higher predictive ability was demonstrated by the SASA, which combines these simple and effective scoring systems.

Impact of the ASA Physical Status Score on Adjuvant Chemotherapy Eligibility and Survival of Upper Tract Urothelial Carcinoma Patients: a Multicenter Study

The aim of the present multi-institutional study was to assess the influence of the American Society of Anesthesiologists Physical Status (ASA-PS) classification on adjuvant chemotherapy eligibility and survival in a multi-institutional cohort of patients treated with radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC). We retrospectively reviewed data from 416 patients who underwent RNU for UTUC at four Korean institutions between 2001 and 2013. The ASA-PS classification was obtained from the anesthesia chart. Locally advanced UTUC was defined as ≥ pT3 and/or pN1 disease. The influence of ASA-PS score on survival was evaluated by Kaplan-Meier analyses and a multivariate Cox regression model. Patients with a higher ASA-PS class were less likely to be eligible for adjuvant chemotherapy in locally advanced UTUC (P = 0.016). Kaplan-Meier estimates showed that the high-risk ASA-PS group has a poorer overallsurvival (OS) and cancer-specific survival (CSS) compared to low risk ASA-PS groups in both the total and locally advanced UTUC cohorts. Based on multivariate Cox regression analysis, the high-risk ASA-PS category was an independent predictor for overall mortality (OM) (hazard ratio [HR], 1.919; 95% confidence interval [CI], 1.017–3.619; P = 0.044) and cancer-specific mortality (CSM) (HR, 2.120; 95% CI, 1.023–4.394; P = 0.043). In conclusion, high-risk ASA-PS score was independently associated with a lower survival rate in patients with UTUC after RNU. However, the influence of ASA-PS classification on survival was limited to locally advanced UTUC. The lower eligibility of patients in the high-risk ASA category for adjuvant chemotherapy may contribute to the lower survival rate in this group.

Evaluation of the American Society of Anesthesiologists Physical Status classification system in risk assessment for plastic and reconstructive surgery patients.

BACKGROUND: The American Society of Anesthesiologists Physical Status (ASA-PS) classification is a ranking system that quantifies patient health before anesthesia and surgery. Some surgical disciplines apply the ASA-PS to gauge a patient's likelihood of developing postoperative complications. OBJECTIVE: In this study, the authors analyze whether ASA-PS scores can successfully predict risk for postoperative complications in plastic and reconstructive operations. METHODS: The authors retrospectively reviewed the charts of 1801 patient procedures and selected for inclusion 1794 complex plastic and reconstructive operations that took place at 1 of several academic medical institutions between January 2008 and January 2012. ASA-PS scores, patient comorbidities, and postoperative complications were analyzed. Percentile data were treated with tests for proportions. Nonpercentile data were analyzed through comparison of means (t test). Low-risk (ASA 1-2) and high-risk (ASA 3+) groups were compared with simple odds ratios. RESULTS: For the 1430 women and 364 men in the patient cohort (average age, 49.5 years), the overall complication rate was 27.7%. When patients with complications were compared to those without, body mass index, operation time, recent major surgery, diabetes, hypertension, renal disease, cancer, and oral contraceptive use were statistically significant. After high-risk (n = 398) and low-risk (n = 1396) groups were identified, infection, delayed wound healing, deep vein thrombosis, and overall complications had significantly increased incidence in the high risk group. Notably, deep vein thrombosis displayed the highest odds ratio (4.17) and a complication rate increase from 0.93% to 3.77%. CONCLUSIONS: ASA-PS scores can be used either as substitutes for or as adjuncts to questionnaire-based risk assessment methods in plastic surgery. In addition to deducing significant findings for deep vein thrombosis incidence, ASA-PS scores hold important predictive associations for multiple non-venous thromboembolism complications, providing a broader measurement for postoperative complication risks. LEVEL OF EVIDENCE: 4.