Computer vision digitization of smartphone images of anesthesia paper health records from low-middle income countries.

BACKGROUND: In low-middle income countries, healthcare providers primarily use paper health records for capturing data. Paper health records are utilized predominately due to the prohibitive cost of acquisition and maintenance of automated data capture devices and electronic medical records. Data recorded on paper health records is not easily accessible in a digital format to healthcare providers. The lack of real time accessible digital data limits healthcare providers, researchers, and quality improvement champions to leverage data to improve patient outcomes. In this project, we demonstrate the novel use of computer vision software to digitize handwritten intraoperative data elements from smartphone photographs of paper anesthesia charts from the University Teaching Hospital of Kigali. We specifically report our approach to digitize checkbox data, symbol-denoted systolic and diastolic blood pressure, and physiological data. METHODS: We implemented approaches for removing perspective distortions from smartphone photographs, removing shadows, and improving image readability through morphological operations. YOLOv8 models were used to deconstruct the anesthesia paper chart into specific data sections. Handwritten blood pressure symbols and physiological data were identified, and values were assigned using deep neural networks. Our work builds upon the contributions of previous research by improving upon their methods, updating the deep learning models to newer architectures, as well as consolidating them into a single piece of software. RESULTS: The model for extracting the sections of the anesthesia paper chart achieved an average box precision of 0.99, an average box recall of 0.99, and an mAP0.5-95 of 0.97. Our software digitizes checkbox data with greater than 99% accuracy and digitizes blood pressure data with a mean average error of 1.0 and 1.36 mmHg for systolic and diastolic blood pressure respectively. Overall accuracy for physiological data which includes oxygen saturation, inspired oxygen concentration and end tidal carbon dioxide concentration was 85.2%. CONCLUSIONS: We demonstrate that under normal photography conditions we can digitize checkbox, blood pressure and physiological data to within human accuracy when provided legible handwriting. Our contributions provide improved access to digital data to healthcare practitioners in low-middle income countries.

Variability in Intraoperative Opioid and Nonopioid Utilization During Intracranial Surgery: A Multicenter, Retrospective Cohort Study.

BACKGROUND: Key goals during intracranial surgery are to facilitate rapid emergence and extubation for early neurologic evaluation. Longer-acting opioids are often avoided or administered at subtherapeutic doses due to their perceived risk of sedation and delayed emergence. However, inadequate analgesia and increased postoperative pain are common after intracranial surgery. In this multicenter study, we describe variability in opioid and nonopioid administration patterns in patients undergoing intracranial surgery. METHODS: This was a multicenter, retrospective observational cohort study using the Multicenter Perioperative Outcomes Group database. Opioid and nonopioid practice patterns in 31,217 cases undergoing intracranial surgery across 11 institutions in the United States are described. RESULTS: Across all 11 institutions, total median [interquartile range] oral morphine equivalents, normalized to weight and anesthesia duration was 0.17 (0.08 to 0.3) mg.kg.min-1. There was a 7-fold difference in oral morphine equivalents between the lowest (0.05 [0.02 to 0.13] mg.kg.min-1) and highest (0.36 [0.18 to 0.54] mg.kg.min-1) prescribing institutions. Patients undergoing supratentorial surgery had higher normalized oral morphine equivalents compared with those having infratentorial surgery [0.17 [0.08-0.31] vs. 0.15 [0.07-0.27] mg/kg/min-1; P<0.001); however, this difference is clinically small. Nonopioid analgesics were not administered in 20% to 96.8% of cases across institutions. CONCLUSION: This study found wide variability for both opioid and nonopioid utilization at an institutional level. Future work on practitioner-level opioid and nonopioid use and its impact on outcomes after intracranial surgery should be conducted.

Racial and Ethnic Disparities in Veno-Venous Extracorporeal Membrane Oxygenation Mortality for Patients With Severe COVID-19.

Racial/ethnic disparities in mortality were observed during the coronavirus disease-2019 pandemic, but investigations examining the association between race/ethnicity and mortality during extracorporeal membrane oxygenation (ECMO) are limited. We performed a retrospective observational cohort study using the 2020 national inpatient sample. Multivariable logistic regression was used to estimate the odds of mortality in patients of difference race/ethnicity while controlling for confounders. There was a significant association between race/ethnicity and in-hospital mortality ( p < 0.001). Hispanic patients had significantly higher in-hospital mortality compared with White patients (odds ratio [OR] = 1.39, 95% confidence interval [CI] = 1.16-1.67, p < 0.001). Black patients and patients of other races did not have significantly higher in-hospital mortality compared with White patients (OR = 0.82, 95% CI = 0.66-1.02, p = 0.07 and OR = 1.20, 95% CI = 0.92-1.57, p = 0.18). Other variables that had a significant association with mortality included age, insurance type, Charlson comorbidity index, all patient-refined severity of illness, and receipt of care in a low-volume ECMO center (all p < 0.001). Further studies are needed to understand causes of disparities in ECMO mortality.

Mobile health supported multi-domain recovery trajectories after major arthroplasty or spine surgery: a pilot feasibility and usability study.

BACKGROUND: Recovery after surgery intersects physical, psychological, and social domains. In this study we aim to assess the feasibility and usability of a mobile health application called PositiveTrends to track recovery in these domains amongst participants undergoing hip, knee arthroplasty or spine surgery. Our secondary aim was to generate procedure-specific, recovery trajectories within the pain and medication, psycho-social and patient-reported outcomes domain. METHODS: Prospective, observational study in participants greater than eighteen years of age. Data was collected prior to and up to one hundred and eighty days after completion of surgery within the three domains using PositiveTrends. Feasibility was assessed using participant response rates from the PositiveTrends app. Usability was assessed quantitatively using the System Usability Scale. Heat maps and effect plots were used to visualize multi-domain recovery trajectories. Generalized linear mixed effects models were used to estimate the change in the outcomes over time. RESULTS: Forty-two participants were enrolled over a four-month recruitment period. Proportion of app responses was highest for participants who underwent spine surgery (median = 78, range = 36-100), followed by those who underwent knee arthroplasty (median = 72, range = 12-100), and hip arthroplasty (median = 62, range = 12-98). System Usability Scale mean score was 82 ± 16 at 180 days postoperatively. Function improved by 8 and 6.4 points per month after hip and knee arthroplasty, respectively. In spine participants, the Oswestry Disability Index decreased by 1.4 points per month. Mood improved in all three cohorts, however stress levels remained elevated in spine participants. Pain decreased by 0.16 (95% Confidence Interval: 0.13-0.20, p < 0.001), 0.25 (95% CI: 0.21-0.28, p < 0.001) and 0.14 (95% CI: 0.12-0.15, p < 0.001) points per month in hip, knee, and spine cohorts respectively. There was a 10.9-to-40.3-fold increase in the probability of using no medication for each month postoperatively. CONCLUSIONS: In this study, we demonstrate the feasibility and usability of PositiveTrends, which can map and track multi-domain recovery trajectories after major arthroplasty or spine surgery.

Comparison of oral versus intravenous methadone on postoperative pain and opioid use after adult spinal deformity surgery: A retrospective, non-inferiority analysis.

OBJECTIVE: To compare efficacy of oral versus intravenous (IV) methadone on postoperative pain and opioid requirements after spine surgery. METHODS: This was a retrospective, single-academic center cohort study evaluating 1010 patients who underwent >3 level spine surgery from January 2017 to May 2020 and received a one-time dose of oral or intravenous methadone prior to surgery. The primary outcome measured was postoperative opioid use in oral morphine equivalents (ME) and verbal response scale (VRS) pain scores up to postoperative day (POD) three. Secondary outcomes were time to first bowel movement and adverse effects (reintubation, myocardial infarction, and QTc prolongation) up to POD 3. RESULTS: A total of 687 patients received oral and 317 received IV methadone, six patients were excluded. The IV group received a significantly greater methadone morphine equivalent (ME) dose preoperatively (112.4 ± 83.0 mg ME versus 59.3 ± 60.9 mg ME, p < 0.001) and greater total (methadone and non-methadone) opioid dose (119.1 ± 81.4 mg ME versus 63.9 ± 62.5 mg ME, p < 0.001), intraoperatively. Although pain scores for the oral group were non-inferior to the IV group for all postoperative days (POD), non-inferiority for postoperative opioid requirements was demonstrated only on POD 3. Based on the joint hypothesis for the co-primary outcomes, oral methadone was non-inferior to IV methadone on POD 3 only. No differences in secondary outcomes, including QTc prolongation and arrhythmias, were noted between the groups. CONCLUSIONS: Oral methadone is a feasible alternative to IV methadone for patients undergoing spine surgery regarding both pain scores and postoperative opioid consumption.

Impact of body mass index on surgical case durations in an academic medical center.

STUDY OBJECTIVE: To investigate the association between patient body mass index (BMI) and operating room duration. DESIGN: Retrospective cohort analysis. SETTING: Demographic data and anesthesia/surgical times for adult surgical patients at University of Virginia Health between August 2017 and February 2019 were collected and analyzed. PATIENTS: A total of 31,548 cases were included in the final analysis. 55% of patients were female, and 51% were classified as ASA Physical Status 2. The mean operating room (OR) duration was 144.2 min ± 112.7 (median = 118, IQR = 121). Orthopedic surgery (32%) was the most common surgery. MEASUREMENTS: Linear mixed effects models were used to examine whether procedure intervals differed across three BMI categories (BMI < 30, 30 ≤ BMI < 40, BMI ≥ 40), considering within-surgeon correlations. Surgical times were log-transformed to correct for positive skewness. MAIN RESULTS: The average time in the operating room was longer for patients with higher BMI (mean ± SD [median, IQR] = 139.5 ± 111.2 [113.0, IQR = 114], 150.2 ± 115.4 [125, IQR = 127], and 153.1 ± 111.1 [130, IQR = 134] for BMI < 30, 30 ≤ BMI < 40, and BMI ≥ 40), respectively. We found a 2% [95% CI = 1-3%] and 3% [95% CI = 1-5%] increase in OR time for 30 ≤ BMI < 40 and BMI ≥ 40, respectively, compared to BMI < 30, after controlling for within-surgeon correlations and covariates. The excess time was primarily determined by anesthesia times. CONCLUSION: In an academic hospital, patients with BMI ≥ 30 required more time in the operating room than patients with BMI < 30, when controlling for confounders. This information can be incorporated into modern-day OR scheduling software, potentially resulting in more accurate case duration estimates that reduce waiting and improve OR efficiency.

Prolonged Opioid Use and Pain Outcome and Associated Factors after Surgery under General Anesthesia: A Prospective Cohort Association Multicenter Study.

BACKGROUND: There is insufficient prospective evidence regarding the relationship between surgical experience and prolonged opioid use and pain. The authors investigated the association of patient characteristics, surgical procedure, and perioperative anesthetic course with postoperative opioid consumption and pain 3 months postsurgery. The authors hypothesized that patient characteristics and intraoperative factors predict opioid consumption and pain 3 months postsurgery. METHODS: Eleven U.S. and one European institution enrolled patients scheduled for spine, open thoracic, knee, hip, or abdominal surgery, or mastectomy, in this multicenter, prospective observational study. Preoperative and postoperative data were collected using patient surveys and electronic medical records. Intraoperative data were collected from the Multicenter Perioperative Outcomes Group database. The association between postoperative opioid consumption and surgical site pain at 3 months, elicited from a telephone survey conducted at 3 months postoperatively, and demographics, psychosocial scores, pain scores, pain management, and case characteristics, was analyzed. RESULTS: Between September and October 2017, 3,505 surgical procedures met inclusion criteria. A total of 1,093 cases were included; 413 patients were lost to follow-up, leaving 680 (64%) for outcome analysis. Preoperatively, 135 (20%) patients were taking opioids. Three months postsurgery, 96 (14%) patients were taking opioids, including 23 patients (4%) who had not taken opioids preoperatively. A total of 177 patients (27%) reported surgical site pain, including 45 (13%) patients who had not reported pain preoperatively. The adjusted odds ratio for 3-month opioid use was 18.6 (credible interval, 10.3 to 34.5) for patients who had taken opioids preoperatively. The adjusted odds ratio for 3-month surgical site pain was 2.58 (1.45 to 4.4), 4.1 (1.73 to 8.9), and 2.75 (1.39 to 5.0) for patients who had site pain preoperatively, knee replacement, or spine surgery, respectively. CONCLUSIONS: Preoperative opioid use was the strongest predictor of opioid use 3 months postsurgery. None of the other variables showed clinically significant association with opioid use at 3 months after surgery.

Incremental Cost-effectiveness Analysis on Length of Stay of an Enhanced Recovery After Spine Surgery Program: A Single-center, Retrospective Cohort Study.

BACKGROUND: Enhanced recovery after spine surgery (ERAS) is increasingly utilized to improve postoperative outcomes and reduce cost. There are limited data on the monetary benefits of ERAS when incorporating the costs of developing, operationalizing, and maintaining ERAS programs. The objective of this study was to calculate the incremental cost-effectiveness of a spine surgery ERAS program, modeling hospital and operational cost and length of stay (LOS). METHODS: The study included adult patients undergoing spine surgery before and after implementation of an ERAS program. Variables included individual patient-level and ERAS personnel costs, with LOS as the outcome utility of interest. Propensity score matching was used to create a quasi-experimental design to equate the standard care and ERAS groups. RESULTS: Four hundred and nine patients were included in the unmatched group, with 54 patients each in the standard care and ERAS groups after matching. In the matched cohort, the only imbalance in predictors (standard mean difference [SMD] >0.2) were race (SMD, 0.21), American Society of Anesthesiologist (ASA) physical status (SMD, 0.32), fluid balance in the operating room (SMD, 0.21), median (interquartile range) LOS (standard care, 2.0 [1.0, 3.75] days vs. ERAS, 4.0 [3.0, 5.0]; SMD, 0.81) and mean (±SD) total cost (standard care, $19,291.57±13,572.24 vs. ERAS, $24,363.45±26,352.45; SMD, 0.24). In the incremental cost effectiveness analysis, standard care was the dominant strategy in both 1-way and 2-way sensitivity analysis. CONCLUSIONS: We report a real-world, cost-effectiveness analysis following implementation of an ERAS program for spine surgery at a quaternary medical center. Our study demonstrated that considering LOS as the sole determinant, standard care is the dominant cost-effective strategy compared with the ERAS protocol.

Enhanced Recovery Protocol Associated With Decreased 3-Month Opioid Use After Thoracic Surgery.

BACKGROUND: Enhanced recovery protocols (ERPs) have been shown to decrease inhospital opioid use after thoracic surgery. However, the impact on opioid use after discharge has not been reported. We hypothesized that prolonged opioid use would decrease after implementation of a comprehensive ERP. METHODS: Records from all patients undergoing elective pulmonary, pleural, and mediastinal operations at a single institution (2015-2018) were abstracted from a prospective ERP database and The Society of Thoracic Surgeons institutional database. Records were reviewed for documentation of opioid use at 3-month and 6-month postoperative visits. Patients with preoperative chronic opioid use were excluded. Univariate analysis compared patients with and patients without 3-month opioid use, and a multivariable logistic regression evaluated independent predictors of prolonged opioid use. RESULTS: A total of 499 patients was included: 160 pre-ERP, and 339 post-ERP. Three-month opioid use rates were decreased after implementation of an ERP (44% vs 30%, P = .01); 6-month opioid use rates were not significantly different (25% vs 18%, P = .10). Univariate analysis demonstrated increased 3-month opioid use rates among patients with preoperative tobacco use (38% vs 27%, P = .05) and chronic pain disorder (88% vs 32%, P < .01), with no impact from surgical incision (video-assisted thoracoscopic surgery 33%; open 37%, P = .49). On multivariable analysis, participation in an ERP was independently associated with decreased opioid use at 3 months (odds ratio 0.53; 95% CI, 0.31-0.89; P = .02). CONCLUSIONS: There is a high burden of prolonged opioid use after elective thoracic surgery. Participation in a comprehensive ERP is associated with decreased opioid use 3 months postoperatively.

Investigating the Association Between a Risk-Directed Prophylaxis Protocol and Postoperative Nausea and Vomiting: Validation in a Low-Income Setting.

BACKGROUND: The efficacy of postoperative nausea and vomiting (PONV) prevention protocols in low-income countries is not well known. Different surgical procedures, available medications, and co-occurring diseases imply that existing protocols may need validation in these settings. We assessed the association of a risk-directed PONV prevention protocol on the incidence of PONV and short-term surgical outcomes in a teaching hospital in Rwanda. METHODS: We compared the incidence of PONV during the first 48 hours postoperatively before (April 1, 2019-June 30, 2019; preintervention) and immediately after (July 1, 2019-September 30, 2019; postintervention) implementing an Apfel score-based PONV prevention strategy in 116 adult patients undergoing elective open abdominal surgery at Kigali University Teaching Hospital in Rwanda. Secondary outcomes included time to first oral intake, hospital length of stay, and rate of wound dehiscence. Interrupted time series analyses were performed to assess the associated temporal slopes of the outcome before and immediately after implementation of the risk-directed PONV prevention protocol. RESULTS: Compared to just before the intervention, there was no change in the odds of PONV at the beginning of the postintervention period (odds ratio [OR], 0.23; 95% confidence interval [CI], 0.05-1.01). There was a decreasing trend in the odds of nausea (OR, 0.60; 95% CI, 0.36-0.97) per month. However, there was no difference in the incidence of nausea immediately after implementation of the protocol (OR, 0.96; 95% CI, 0.25-3.72) or in the slope between preintervention and postintervention periods (OR, 1.48; 95% CI, 0.60-3.65). In contrast, there was no change in the odds of vomiting during the preintervention period (OR, 1.01; 95% CI, 0.61-1.67) per month. The odds of vomiting decreased at the beginning of the postintervention period compared to just before (OR, 0.10; 95% CI, 0.02-0.47; P = .004). Finally, there was a significant decrease in the average time to first oral intake (estimated 14 hours less; 95% CI, -25 to -3) when the protocol was first implemented, after adjusting for confounders; however, there was no difference in the slope of the average time to first oral intake between the 2 periods ( P = .44). CONCLUSIONS: A risk-directed PONV prophylaxis protocol was associated with reduced vomiting and time to first oral intake after implementation. There was no substantial difference in the slopes of vomiting incidence and time to first oral intake before and after implementation.

Digitization of Symbol-Denoted Blood Pressure Data From Intraoperative Paper Health Records in a Low-Middle-Income Country Using Deep Image Segmentation and Associated Postoperative Outcomes: A Feasibility Study.

BACKGROUND: In low-middle-income countries (LMICs), perioperative clinical information is almost universally collected on paper health records (PHRs). The lack of accessible digital databases limits LMICs in leveraging data to predict and improve patient outcomes after surgery. In this feasibility study, our aims were to: (1) determine the detection performance and prediction error of the U-Net deep image segmentation approach for digitization of hand-drawn blood pressure symbols from an image of the intraoperative PHRs and (2) evaluate the association between deep image segmentation-derived blood pressure parameters and postoperative mortality and length of stay. METHODS: A smartphone mHealth platform developed by our team was used to capture images of completed intraoperative PHRs. A 2-stage deep image segmentation modeling approach was used to create 2 separate segmentation masks for systolic blood pressure (SBP) and diastolic blood pressure (DBP). Iterative postprocessing was utilized to convert the segmentation mask results into numerical SBP and DBP values. Detection performance and prediction errors were evaluated for the U-Net models by comparison with ground-truth values. Using multivariate regression analysis, we investigated the association of deep image segmentation-derived blood pressure values, total time spent in predefined blood pressure ranges, and postoperative outcomes including in-hospital mortality and length of stay. RESULTS: A total of 350 intraoperative PHRs were imaged following surgery. Overall accuracy was 0.839 and 0.911 for SBP and DBP symbol detections, respectively. The mean error rate and standard deviation for the difference between the actual and predicted blood pressure values were 2.1 ± 4.9 and -0.8 ± 3.9 mm Hg for SBP and DBP, respectively. Using the U-Net model-derived blood pressures, minutes of time where DBP <50 mm Hg (odds ratio [OR], 1.03; CI, 1.01-1.05; P = .003) was associated with an increased in-hospital mortality. In addition, increased cumulative minutes of time with SBP between 80 and 90 mm Hg was significantly associated with a longer length of stay (incidence rate ratio, 1.02 [1.0-1.03]; P < .05), while increased cumulative minutes of time where SBP between 140 and 160 mm Hg was associated with a shorter length of stay (incidence rate ratio, 0.9 [0.96-0.99]; P < .05). CONCLUSIONS: In this study, we report our experience with a deep image segmentation model for digitization of symbol-denoted blood pressure from intraoperative anesthesia PHRs. Our data support further development of this novel approach to digitize PHRs from LMICs, to provide accessible, curated, and reproducible data for both quality improvement- and outcome-based research.

Carbon Dioxide, Blood Pressure, and Perioperative Stroke: A Retrospective Case-Control Study.

BACKGROUND: The relationship between intraoperative physiology and postoperative stroke is incompletely understood. Preliminary data suggest that either hypo- or hypercapnia coupled with reduced cerebrovascular inflow (e.g., due to hypotension) can lead to ischemia. This study tested the hypothesis that the combination of intraoperative hypotension and either hypo- or hypercarbia is associated with postoperative ischemic stroke. METHODS: We conducted a retrospective, case-control study via the Multicenter Perioperative Outcomes Group. Noncardiac, nonintracranial, and nonmajor vascular surgical cases (18 yr or older) were extracted from five major academic centers between January 2004 and December 2015. Ischemic stroke cases were identified via manual chart review and matched to controls (1:4). Time and reduction below key mean arterial blood pressure thresholds (less than 55 mmHg, less than 60 mmHg, less than 65 mmHg) and outside of specific end-tidal carbon dioxide thresholds (30 mmHg or less, 35 mmHg or less, 45 mmHg or greater) were calculated based on total area under the curve. The association between stroke and total area under the curve values was then tested while adjusting for relevant confounders. RESULTS: In total, 1,244,881 cases were analyzed. Among the cases that screened positive for stroke (n = 1,702), 126 were confirmed and successfully matched with 500 corresponding controls. Total area under the curve was significantly associated with stroke for all thresholds tested, with the strongest combination observed with mean arterial pressure less than 55 mmHg (adjusted odds ratio per 10 mmHg-min, 1.17 [95% CI, 1.10 to 1.23], P < 0.0001) and end-tidal carbon dioxide 45 mmHg or greater (adjusted odds ratio per 10 mmHg-min, 1.11 [95% CI, 1.10 to 1.11], P < 0.0001). There was no interaction effect observed between blood pressure and carbon dioxide. CONCLUSIONS: Intraoperative hypotension and carbon dioxide dysregulation may each independently increase postoperative stroke risk.

A Novel Hemodynamic Index of Post-operative Right Heart Dysfunction Predicts Mortality in Cardiac Surgical Patients.

INTRODUCTION: This study aimed to investigate whether mortality following cardiac surgery was associated with the pulmonary artery pulsatility index (PAPi): pulmonary artery pulse pressure divided by central venous pressure (CVP), and a novel index: mean pulmonary artery pressure (mPAP) minus CVP. METHODS: This retrospective analysis investigated all cardiac surgery patients in the Society of Thoracic Surgeons registry at a single academic medical center from January 2017 through March 2020 (n = 1510). The primary and secondary outcomes were mortality at 1 year and serum creatinine increase during index surgical admission, respectively. CVP, mPAP, PAPi, mPAP-CVP gradient, mean arterial pressure (MAP), and cardiac index (CI) were sampled continually from invasive hemodynamic monitors post-operatively. Associations with mortality were tested with univariate and multivariate analyses. The relationship with serum creatinine was investigated with Pearson's correlation at alpha = .05. RESULTS: One-year mortality was observed in 44/1200 patients (3.7%). On univariate analysis, mortality was associated with minimums for mPAP, MAP, and CI and maximums for CVP, mPAP, PAPi, mPAP-CVP gradient, and CI (all P < .10). Model selection revealed that the only independently predictive parameters were minimum MAP (AOR = .880 [.819-.944]), maximum mPAP-CVP gradient (AOR = 1.082 [1.031-1.133]), and maximum CI (AOR = 1.421 [.928-2.068]), with model c-statistic = .770. A maximum mPAP-CVP gradient >20.5 predicted mortality with 54.5% sensitivity and 79.30% specificity, maintaining significance on survival analysis (P < .001). Peak increase in serum creatinine from baseline demonstrated a weak association with all parameters (max |r| = .33). CONCLUSIONS: Mortality was not predicted by the post-operative PAPi; rather, it was independently predicted by the mPAP-CVP gradient, MAP, and CI.

Practice Patterns and Variability in Intraoperative Opioid Utilization: A Report From the Multicenter Perioperative Outcomes Group.

BACKGROUND: Opioids remain the primary mode of analgesia intraoperatively. There are limited data on how patient, procedural, and institutional characteristics influence intraoperative opioid administration. The aim of this retrospective, longitudinal study from 2012 to 2016 was to assess how intraoperative opioid dosing varies by patient and clinical care factors and across multiple institutions over time. METHODS: Demographic, surgical procedural, anesthetic technique, and intraoperative analgesia data as putative variables of intraoperative opioid utilization were collected from 10 institutions. Log parenteral morphine equivalents (PME) was modeled in a multivariable linear regression model as a function of 15 covariates: 3 continuous covariates (age, anesthesia duration, year) and 12 factor covariates (peripheral block, neuraxial block, general anesthesia, emergency status, race, sex, remifentanil infusion, major surgery, American Society of Anesthesiologists [ASA] physical status, non-opioid analgesic count, Multicenter Perioperative Outcomes Group [MPOG] institution, surgery category). One interaction (year by MPOG institution) was included in the model. The regression model adjusted simultaneously for all included variables. Comparison of levels within a factor were reported as a ratio of medians with 95% credible intervals (CrI). RESULTS: A total of 1,104,324 cases between January 2012 and December 2016 were analyzed. The median (interquartile range) PME and standardized by weight PME per case for the study period were 15 (10-28) mg and 200 (111-347) µg/kg, respectively. As estimated in the multivariable model, there was a sustained decrease in opioid use (mean, 95% CrI) dropping from 152 (151-153) µg/kg in 2012 to 129 (129-130) µg/kg in 2016. The percent of variability in PME due to institution was 25.6% (24.8%-26.5%). Less opioids were prescribed in men (130 [129-130] µg/kg) than women (144 [143-145] µg/kg). The men to women PME ratio was 0.90 (0.89-0.90). There was substantial variability in PME administration among institutions, with the lowest being 80 (79-81) µg/kg and the highest being 186 (184-187) µg/kg; this is a PME ratio of 0.43 (0.42-0.43). CONCLUSIONS: We observed a reduction in intraoperative opioid administration over time, with variability in dose ranging between sexes and by procedure type. Furthermore, there was substantial variability in opioid use between institutions even when adjusting for multiple variables.

Airway driving pressure is associated with postoperative pulmonary complications after major abdominal surgery: a multicentre retrospective observational cohort study.

Background: High airway driving pressure is associated with adverse outcomes in critically ill patients receiving mechanical ventilation, but large multicentre studies investigating airway driving pressure during major surgery are lacking. We hypothesised that increased driving pressure is associated with postoperative pulmonary complications in patients undergoing major abdominal surgery. Methods: In this preregistered multicentre retrospective observational cohort study, the authors reviewed major abdominal surgical procedures in 11 hospitals from 2004 to 2018. The primary outcome was a composite of postoperative pulmonary complications, defined as postoperative pneumonia, unplanned tracheal intubation, or prolonged mechanical ventilation for more than 48 h. Associations between intraoperative dynamic driving pressure and outcomes, adjusted for patient and procedural factors, were evaluated. Results: Among 14 218 qualifying cases, 389 (2.7%) experienced postoperative pulmonary complications. After adjustment, the mean dynamic driving pressure was associated with postoperative pulmonary complications (adjusted odds ratio for every 1 cm H2O increase: 1.04; 95% confidence interval [CI], 1.02-1.06; P<0.001). Neither tidal volume nor PEEP was associated with postoperative pulmonary complications. Increased BMI, shorter height, and female sex were predictors for higher dynamic driving pressure (ß=0.35, 95% CI 0.32-0.39, P<0.001; ß=-0.01, 95% CI -0.02 to 0.00, P=0.005; and ß=0.74, 95% CI 0.63-0.86, P<0.001, respectively). Conclusions: Dynamic airway driving pressure, but not tidal volume or PEEP, is associated with postoperative pulmonary complications in models controlling for a large number of risk predictors and covariates. Such models are capable of risk prediction applicable to individual patients.

Recommended Primary Outcomes for Clinical Trials Evaluating Hemostatic Agents in Patients With Intracranial Hemorrhage: A Consensus Statement.

Importance: In patients with acute spontaneous or traumatic intracranial hemorrhage, early hemostasis is thought to be critical to minimize ongoing bleeding. However, research evaluating hemostatic therapies has been hampered by a lack of standardized clinical trial outcome measures. Objective: To identify appropriate primary outcomes for phase 2 and 3 clinical trials of therapies aimed at reducing acute intracranial bleeding. Evidence Review: A comprehensive review of all previous clinical trials of hemostatic therapy for intracranial bleeding was performed, and studies measuring the frequency, risk factors, and association of intracranial bleeding with outcome of hemorrhage growth were included. Findings: A hierarchy of 3 outcome measures is recommended, with the first choice being a global patient-centered clinical outcome scale measured 30 to 180 days after the event; the second, a combined clinical and radiographic end point associating hemorrhage expansion with a poor patient-centered outcome at 24 hours or later; and the third, a radiographic measure of hemorrhage expansion at 24 hours alone. Additional recommendations stress the importance of separating various subtypes of bleeding when possible, early treatment within a standardized treatment window, and the routine use of computerized planimetry comparing continuous measures of absolute and relative hemorrhage growth as either a primary or secondary end point. Conclusions and Relevance: Standardization of outcome measures in studies of intracranial bleeding and hemostatic therapy will support comparative effectiveness research and meta-analysis, with the goal of accelerating the translation of research into clinical practice. The 3 outcome measures proposed in this consensus statement could help this process.

A Lower Tidal Volume Regimen during One-lung Ventilation for Lung Resection Surgery Is Not Associated with Reduced Postoperative Pulmonary Complications.

BACKGROUND: Protective ventilation may improve outcomes after major surgery. However, in the context of one-lung ventilation, such a strategy is incompletely defined. The authors hypothesized that a putative one-lung protective ventilation regimen would be independently associated with decreased odds of pulmonary complications after thoracic surgery. METHODS: The authors merged Society of Thoracic Surgeons Database and Multicenter Perioperative Outcomes Group intraoperative data for lung resection procedures using one-lung ventilation across five institutions from 2012 to 2016. They defined one-lung protective ventilation as the combination of both median tidal volume 5 ml/kg or lower predicted body weight and positive end-expiratory pressure 5 cm H2O or greater. The primary outcome was a composite of 30-day major postoperative pulmonary complications. RESULTS: A total of 3,232 cases were available for analysis. Tidal volumes decreased modestly during the study period (6.7 to 6.0 ml/kg; P < 0.001), and positive end-expiratory pressure increased from 4 to 5 cm H2O (P < 0.001). Despite increasing adoption of a "protective ventilation" strategy (5.7% in 2012 vs. 17.9% in 2016), the prevalence of pulmonary complications did not change significantly (11.4 to 15.7%; P = 0.147). In a propensity score matched cohort (381 matched pairs), protective ventilation (mean tidal volume 6.4 vs. 4.4 ml/kg) was not associated with a reduction in pulmonary complications (adjusted odds ratio, 0.86; 95% CI, 0.56 to 1.32). In an unmatched cohort, the authors were unable to define a specific alternative combination of positive end-expiratory pressure and tidal volume that was associated with decreased risk of pulmonary complications. CONCLUSIONS: In this multicenter retrospective observational analysis of patients undergoing one-lung ventilation during thoracic surgery, the authors did not detect an independent association between a low tidal volume lung-protective ventilation regimen and a composite of postoperative pulmonary complications.