Browsing by Author "Schonberger, Robert B"

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    ItemOpen Access
    Demonstration and Performance Evaluation of Two Novel Algorithms for Removing Artifacts From Automated Intraoperative Temperature Data Sets: Multicenter, Observational, Retrospective Study.
    (JMIR perioperative medicine, 2022-10) Bardia, Amit; Deshpande, Ranjit; Michel, George; Yanez, David; Dai, Feng; Pace, Nathan L; Schuster, Kevin; Mathis, Michael R; Kheterpal, Sachin; Schonberger, Robert B

    Background

    The automated acquisition of intraoperative patient temperature data via temperature probes leads to the possibility of producing a number of artifacts related to probe positioning that may impact these probes' utility for observational research.

    Objective

    We sought to compare the performance of two de novo algorithms for filtering such artifacts.

    Methods

    In this observational retrospective study, the intraoperative temperature data of adults who received general anesthesia for noncardiac surgery were extracted from the Multicenter Perioperative Outcomes Group registry. Two algorithms were developed and then compared to the reference standard-anesthesiologists' manual artifact detection process. Algorithm 1 (a slope-based algorithm) was based on the linear curve fit of 3 adjacent temperature data points. Algorithm 2 (an interval-based algorithm) assessed for time gaps between contiguous temperature recordings. Sensitivity and specificity values for artifact detection were calculated for each algorithm, as were mean temperatures and areas under the curve for hypothermia (temperatures below 36 C) for each patient, after artifact removal via each methodology.

    Results

    A total of 27,683 temperature readings from 200 anesthetic records were analyzed. The overall agreement among the anesthesiologists was 92.1%. Both algorithms had high specificity but moderate sensitivity (specificity: 99.02% for algorithm 1 vs 99.54% for algorithm 2; sensitivity: 49.13% for algorithm 1 vs 37.72% for algorithm 2; F-score: 0.65 for algorithm 1 vs 0.55 for algorithm 2). The areas under the curve for time × hypothermic temperature and the mean temperatures recorded for each case after artifact removal were similar between the algorithms and the anesthesiologists.

    Conclusions

    The tested algorithms provide an automated way to filter intraoperative temperature artifacts that closely approximates manual sorting by anesthesiologists. Our study provides evidence demonstrating the efficacy of highly generalizable artifact reduction algorithms that can be readily used by observational studies that rely on automated intraoperative data acquisition.
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    ItemOpen Access
    Perioperative Complications in Patients with Systemic Sclerosis: A Comparative Cohort Analysis.
    (Medical research archives, 2023-10) Carr, Zyad J; Yan, Luying; Yanez, N David; Schonberger, Robert B; Bohorquez, Manuel; He, Zili; Li, Fangyong; Hines, Roberta L; Treggiari, Miriam M

    Background

    Systemic sclerosis (SSc) is a rare autoimmune disorder with pathological manifestations affecting multiple organ systems. Few studies have examined perioperative outcomes in patients with this disorder. The primary aim of this retrospective single-center comparative cohort analysis was to estimate the incidence of select perioperative complications in a population of SSc patients. In an exploratory analysis, we analyzed the relationship between SSc and susceptibility to select perioperative complications when treated at a large quaternary-care institution.

    Methods

    We conducted a single-center retrospective, comparative cohort study to compare perioperative outcomes in a SSc (n=258) and a frequency matched control cohort (n=632). We analyzed for the presence of major composite infection (MCI), major adverse cardiac events (MACE), 30-day readmission, 30-day mortality, in-hospital complications, length of stay and airway management outcomes.

    Results

    MCI was higher in the SSc compared to the control cohort [adjusted odds ratio (ORadj)=5.02 (95%CI: 2.47-10.20) p<0.001]. Surgical site infection (3.5% vs. 0%, p<0.001), and other infection types (5% vs. 0%, p<0.001) were higher in the SSc cohort. MACE was not significantly different between SSc vs. Control groups [6.2% vs. 7.9%, ORadj=1.33 (95%CI: 0.61-2.91) p=0.48]. Higher rates of limited cervical range of motion (13.6% vs. 3.5%, p<0.001), microstomia (11.5% vs. 1.3%, p<0.001) and preoperative difficult airway designation (8.7% vs. 0.5%, p<0.001) were observed in the SSc cohort. Bag mask ventilation grade was similar between groups (p=0.44). After adjustment, there was no between-group difference in Cormack-Lehane grade 3 and 4 view on direct laryngoscopy in SSc patients [ORadj = 1.86 (95%CI: 0.612 -5.66) p=0.18] but evidence of higher rates of video laryngoscopy [ORadj= 1.87 (95%CI:1.07 - 3.27) p=0.03]. Length of stay [median: 0.2 vs. 0.3 days, p=0.08], 30-day mortality [1.2% vs. 0.6%, ORadj=2.79 (95%CI: 0.50-15.6) p=0.24] and readmission [11.5% vs. 8.1%, ORadj=1.64 (95%CI: 0.96 - 2.82) p=0.07] were not statistically significant.

    Conclusions

    SSc patients demonstrate mostly similar rates of MACE, 30-day mortality, length of stay intraoperative and airway complications. There is evidence of increased risk of overall 30-day MCI risk and readmission after endoscopic procedures.
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    Variation in propofol induction doses administered to surgical patients over age 65.
    (Journal of the American Geriatrics Society, 2021-08) Schonberger, Robert B; Bardia, Amit; Dai, Feng; Michel, George; Yanez, David; Curtis, Jeptha P; Vaughn, Michelle T; Burg, Matthew M; Mathis, Michael; Kheterpal, Sachin; Akhtar, Shamsuddin; Shah, Nirav

    Background/objectives

    Advanced age is associated with increased susceptibility to acute adverse effects of propofol. The present study aimed to describe patterns of propofol dosing for induction of general anesthesia before endotracheal intubation in a nationwide sample of older adults presenting for surgery.

    Design

    Retrospective observational study using the Multicenter Perioperative Outcomes Group data set.

    Setting

    Thirty-six institutions across the United States.

    Participants

    A total of 350,766 patients aged over 65 years who received propofol for general anesthetic induction and endotracheal intubation between 2014 and 2018.

    Intervention

    None.

    Measurements

    Total induction bolus dose of propofol administered.

    Results

    The mean (SD) weight-adjusted propofol dose was 1.7 (0.6) mg/kg. The mean prevalent propofol induction dose exceeded the upper bound of what has been described as the typical geriatric dose requirement across every age category examined. The percent of patients receiving propofol induction doses above the described typical geriatric range was 64.8% (95% CI 64.6-65.0), varying from 73.8% among patients aged 65-69 to 45.8% among patients aged 80 and older.

    Conclusion

    The present study of a large multicenter cohort demonstrates that prevalent propofol dosing commonly falls above the published typically required dose range for patients aged ≥65 in nationwide anesthetic practice. Widespread variability in induction dose administration remains incompletely explained by known patient variables. The nature and clinical consequences of these unexplained dosing decisions remain important topics for further study. Observed discordance between expected and actual induction dosing raises the question of whether there should be reconsideration of widespread provider practice or, alternatively, whether what is published as the typical propofol induction dose range should be revisited.