F Dexter


Affiliation: University of Iowa
Country: USA


  1. Dexter F, Lee J, Dow A, Lubarsky D. A psychological basis for anesthesiologists' operating room managerial decision-making on the day of surgery. Anesth Analg. 2007;105:430-4 pubmed
    ..Rather, the heuristic followed is consistent with increasing one's personal clinical work per unit time at one's assigned anesthetizing location. ..
  2. Dexter F, Epstein R. Typical savings from each minute reduction in tardy first case of the day starts. Anesth Analg. 2009;108:1262-7 pubmed publisher
    ..If small, the analyst and/or clinician can promptly speak up and refocus group conversation toward other potential interventions. If large, the full return on investment analysis would be performed. ..
  3. Dexter F, Xiao Y, Dow A, Strader M, Ho D, Wachtel R. Coordination of appointments for anesthesia care outside of operating rooms using an enterprise-wide scheduling system. Anesth Analg. 2007;105:1701-10, table of contents pubmed
    ..g., at facilities with limited physical space). ..
  4. Dexter F. Why calculating PACU staffing is so hard and why/how operations research specialists can help. J Perianesth Nurs. 2007;22:357-9 pubmed
  5. Dexter F, Blake J, Penning D, Sloan B, Chung P, Lubarsky D. Use of linear programming to estimate impact of changes in a hospital's operating room time allocation on perioperative variable costs. Anesthesiology. 2002;96:718-24 pubmed
    ..The OR manager can reduce the potential increase in costs by considering not just OR time, but also the resulting use of hospital beds and implants. ..
  6. Vasilopoulos T, Dexter F, Van Swol L, Fahy B. Trust improves during one-day resident operating room management course preceded by directed study of required statistical content. J Clin Anesth. 2019;55:43-49 pubmed publisher
    ..The 1-day course increases resident trust in OR course management content. Participants with less pre-course confidence in statistical application and decision making had greater increases in trust. ..
  7. Dexter F, Epstein R. Influence of Annual Meetings of the American Society of Anesthesiologists and of Large National Surgical Societies on Caseloads of Major Therapeutic Procedures. J Med Syst. 2018;42:259 pubmed publisher
    ..0%]), and fewer cases (P = 0.018, -5.9% [2.0%]). The results show that, in routine practice, anesthesia staffing and staff scheduling are being chosen to prevent the meeting from affecting patients' and surgeons' access to OR time. ..
  8. Dexter F, Macario A, Ledolter J. Identification of systematic underestimation (bias) of case durations during case scheduling would not markedly reduce overutilized operating room time. J Clin Anesth. 2007;19:198-203 pubmed
  9. Dexter F, Epstein R, Schwenk E. Tardiness of starts of surgical cases is not substantively greater when the preceding surgeon in an operating room is of a different versus the same specialty. J Clin Anesth. 2019;53:20-26 pubmed publisher
    ..Case scheduling should focus on reducing over-utilized OR time and thus the hours that anesthesiologists and nurses work late. ..

More Information


  1. Dexter F, Ledolter J. Bayesian prediction bounds and comparisons of operating room times even for procedures with few or no historic data. Anesthesiology. 2005;103:1259-167 pubmed
    ..The authors validated a practical way to calculate prediction bounds and compare the OR times of all cases, even those with few or no historic data for the surgeon and the scheduled procedure(s). ..
  2. Thenuwara K, Yoshimura T, Nakata Y, Dexter F. Time to recovery after general anesthesia at hospitals with and without a phase I post-anesthesia care unit: a historical cohort study. Can J Anaesth. 2018;65:1296-1302 pubmed publisher
    ..e., when there will not be an available PACU bed and/or nurse). The Japanese anesthesiologists have no PACU labour costs but likely greater anesthesia drug/monitor costs. ..
  3. Dexter F, Jarvie C, Epstein R. Lack of a substantive effect of insurance and the national US payment system on the relative distribution of surgical cases among hospitals in the State of Iowa: A retrospective, observational, cohort study. J Clin Anesth. 2018;51:98-107 pubmed publisher
    ..Anesthesia groups should focus on payer and payment reform in terms of their effects on payment rates (e.g., average payment per relative value guide unit), not on their potential effects on hospital caseloads. ..
  4. Epstein R, Dexter F, Maratea E. Unscheduled absences in a cohort of nurse anesthetists during a 3-year period: Statistical implications for the identification of outlier personnel. J Clin Anesth. 2019;52:1-5 pubmed publisher
    ..OR managers can detect CRNAs with excessive numbers of unscheduled absences, but at least a year of data is required. Detecting apparent "patterns" of absences would require multiple years of data and is thus impractical. ..
  5. Dexter F, Witkowski T, Epstein R. Forecasting preanesthesia clinic appointment duration from the electronic medical record medication list. Anesth Analg. 2012;114:670-3 pubmed publisher
    ..This approach can take schedulers only approximately 10 seconds extra per patient when scheduling the appointment. ..
  6. Dexter F, Epstein R, Ledolter J, Wanderer J. Interchangeability of counts of cases and hours of cases for quantifying a hospital's change in workload among four-week periods of 1 year. J Clin Anesth. 2018;49:118-125 pubmed publisher
    ..Simple control chart methods of detecting sudden changes in workload or caseload, based simply on the sample mean and standard deviation from the preceding year, are appropriate. ..
  7. Elhag D, Dexter F, Elhakim M, Epstein R. Many US hospital-affiliated freestanding ambulatory surgery centers are located on hospital campuses, relevant to interpretation of studies involving ambulatory surgery. J Clin Anesth. 2018;49:88-91 pubmed publisher
    ..Similarly, hospital affiliated freestanding surgery centers should not be assumed to be more than a 5 min walk for anesthesia and operating room personnel from the hospital. ..
  8. Loftus R, Dexter F, Robinson A, Horswill A. Desiccation tolerance is associated with Staphylococcus aureus hypertransmissibility, resistance and infection development in the operating room. J Hosp Infect. 2018;100:299-308 pubmed publisher
    ..aureus ST 5 isolates that are linked to postoperative infection. Future work should determine whether attenuation of desiccation-tolerant, intraoperative ST 5 strains can impact the incidence of healthcare-associated infections. ..
  9. Dexter F, Epstein R, Jarvie C, Thenuwara K. At all hospitals in the State of Iowa over a decade, the number of cases performed during weekends or holidays increased approximately proportionally to the total caseload. J Clin Anesth. 2018;50:27-32 pubmed publisher
    ..Average weekend workload can be benchmarked using hospitals' percentages of operating room cases performed on weekends and holidays. ..
  10. Dexter F, Epstein R, Lubarsky D. Hospitals with greater diversities of physiologically complex procedures do not achieve greater surgical growth in a market with stable numbers of such procedures. J Clin Anesth. 2018;46:67-73 pubmed publisher
  11. Dexter F, Maguire D, Epstein R. Observational study of anaesthetists' fresh gas flow rates during anaesthesia with desflurane, isoflurane and sevoflurane. Anaesth Intensive Care. 2011;39:460-4 pubmed
    ..These results show that departments choosing to use inexpensive automatic email feedback on FGF should target all anaesthetists and focus on variation in FGF among anaesthetists' cases. ..
  12. Dexter F, Hindman B. Recommendations for hyperbaric oxygen therapy of cerebral air embolism based on a mathematical model of bubble absorption. Anesth Analg. 1997;84:1203-7 pubmed
  13. Dexter F, Jarvie C, Epstein R. Heterogeneity among hospitals statewide in percentage shares of the annual growth of surgical caseloads of inpatient and outpatient major therapeutic procedures. J Clin Anesth. 2018;49:126-130 pubmed publisher
  14. Dexter F, Epstein R, Elgart R, Ledolter J. Forecasting and perception of average and latest hours worked by on-call anesthesiologists. Anesth Analg. 2009;109:1246-52 pubmed publisher
    ..The data are useful because experience provides limited intuition. Updates on scheduled workload available closer to the day of surgery provided only marginal increases in knowledge over the use of historical data. ..
  15. Logvinov I, Dexter F, Hindman B, Brull S. Anesthesiologists' perceptions of minimum acceptable work habits of nurse anesthetists. J Clin Anesth. 2017;38:107-110 pubmed publisher
    ..e., of 3.69). Instead, work habits scores should be analyzed based on relative reporting among anesthetists. ..
  16. Dexter F, Macario A, O Neill L. A strategy for deciding operating room assignments for second-shift anesthetists. Anesth Analg. 1999;89:920-4 pubmed
    ..A relief strategy that relies only on analyzing historical case durations from an operating room information system to predict the time remaining in cases performs well at minimizing anesthetist staffing costs. ..
  17. Dexter F, Macario A, Traub R. Which algorithm for scheduling add-on elective cases maximizes operating room utilization? Use of bin packing algorithms and fuzzy constraints in operating room management. Anesthesiology. 1999;91:1491-500 pubmed
    ..The ease of implementation of the algorithm, either manually or in an OR information system, needs to be studied. ..
  18. Dexter F, Epstein R. For assessment of changes in intraoperative red blood cell transfusion practices over time, the pooled incidence of transfusion correlates highly with total units transfused. J Clin Anesth. 2017;39:53-56 pubmed publisher
    ..0001). For assessment of changes in intraoperative RBC transfusion practices over years, it is sufficient to analyze the pooled incidence of transfusion, rather than to calculate the number of units transfused. ..
  19. Dexter F, Rittenmeyer H. A statistical method for predicting postanesthesia care unit staffing needs. AORN J. 1997;65:947-50, 952-3, 955-7 pubmed
  20. Dexter F, Abouleish A, Epstein R, Whitten C, Lubarsky D. Use of operating room information system data to predict the impact of reducing turnover times on staffing costs. Anesth Analg. 2003;97:1119-26, table of contents pubmed
    ..Staffing cost reductions are generally very small and would be achieved predominantly by reducing allocated OR time to the surgeons. ..
  21. Dexter F, Epstein R. Calculating institutional support that benefits both the anesthesia group and hospital. Anesth Analg. 2008;106:544-53, table of contents pubmed publisher
    ..e., OR allocations). Such an agreement creates incentives whereby the hospital and anesthesia group both profit from increased OR workload and from more accurate specialty-specific staffing. ..
  22. Dexter F, Marcon E, Aker J, Epstein R. Numbers of simultaneous turnovers calculated from anesthesia or operating room information management system data. Anesth Analg. 2009;109:900-5 pubmed publisher
  23. Dexter F, Wachtel R, Epstein R. Impact of average patient acuity on staffing of the phase I PACU. J Perianesth Nurs. 2006;21:303-10 pubmed
    ..Methods are described for adjusting staffing requirements when some patient acuities differ from 1 nurse:2 patients, when patients transition from one acuity to another, and when acuity is not known for all patients. ..
  24. Dexter F. A strategy to decide whether to move the last case of the day in an operating room to another empty operating room to decrease overtime labor costs. Anesth Analg. 2000;91:925-8 pubmed
  25. Dexter F, Epstein R, Lee J, Ledolter J. Automatic updating of times remaining in surgical cases using bayesian analysis of historical case duration data and "instant messaging" updates from anesthesia providers. Anesth Analg. 2009;108:929-40 pubmed publisher
    ..We implemented automated calculation of times remaining for every case at a 29 OR hospital. ..
  26. Dexter F, Epstein R. Holiday and weekend operating room on-call staffing requirements. Anesth Analg. 2006;103:1494-8 pubmed
    ..To be useful, the statistic must be combined with mathematically valid assessments of appropriate weekend staffing on-call, whether in-house, or from home. ..
  27. Epstein R, Dexter F, Schwenk E, Witkowski T. Bypass of an anesthesiologist-directed preoperative evaluation clinic results in greater first-case tardiness and turnover times. J Clin Anesth. 2017;41:112-119 pubmed publisher
    ..A strategy of selective bypass of ASA PS 1-2 patients would not be effective economically because of substantial delays from ASA PS 2 patients. ..
  28. Dexter F, Epstein R, Marcon E, Ledolter J. Estimating the incidence of prolonged turnover times and delays by time of day. Anesthesiology. 2005;102:1242-8; discussion 6A pubmed
    ..Managers can target their quality improvement efforts on times of the day with the largest percentages of prolonged turnovers. ..
  29. Dexter F, Ledolter J, Hindman B. Measurement of faculty anesthesiologists' quality of clinical supervision has greater reliability when controlling for the leniency of the rating anesthesia resident: a retrospective cohort study. Can J Anaesth. 2017;64:643-655 pubmed publisher
    ..Use of logistic regression with leniency results in greater detection of anesthesiologists with significantly better (or worse) clinical supervision scores than use of Student's t tests (i.e., without adjustment for rater leniency). ..
  30. Dexter F, Szeluga D, Hindman B. Content analysis of resident evaluations of faculty anesthesiologists: supervision encompasses some attributes of the professionalism core competency. Can J Anaesth. 2017;64:506-512 pubmed publisher
    ..The core competency of professionalism, however, is multidimensional, and the supervision scale and/or residents' comments did not address many of the other established attributes of professionalism. ..
  31. Dexter F, Traub R. The lack of systematic month-to-month variation over one-year periods in ambulatory surgery caseload -application to anesthesia staffing. Anesth Analg. 2000;91:1426-30 pubmed
    ..These findings suggest that the relatively simple statistical methods that are available to estimate future anesthesia workload will work for many anesthesia groups. ..
  32. Dexter F, Willemsen Dunlap A, Lee J. Operating room managerial decision-making on the day of surgery with and without computer recommendations and status displays. Anesth Analg. 2007;105:419-29 pubmed
    ..Organizational culture and socialization during clinical training may be a cause. Command displays showed promise in mitigating this tendency. Additional investigations are in our companion paper. ..
  33. Dexter F. Bed management displays to optimize patient flow from the OR to the PACU. J Perianesth Nurs. 2007;22:218-9 pubmed
  34. Dexter F, Macario A, Traub R. Optimal sequencing of urgent surgical cases. Scheduling cases using operating room information systems. J Clin Monit Comput. 1999;15:153-62 pubmed
    ..We use an example to illustrate that the optimal sequence varies depending on the scheduling objective chosen. ..
  35. Dexter F, Jarvie C, Epstein R. Lack of generalizability of observational studies' findings for turnover time reduction and growth in surgery based on the State of Iowa, where from one year to the next, most growth was attributable to surgeons performing only a few cases per week. J Clin Anesth. 2018;44:107-113 pubmed publisher
    ..Although reducing turnover times and anesthesia-controlled times to promote growth will be beneficial for a few surgeons, the effect on total caseload will be small. ..
  36. Dexter F, Jarvie C, Epstein R. At most hospitals in the state of Iowa, most surgeons' daily lists of elective cases include only 1 or 2 cases: Individual surgeons' percentage operating room utilization is a consistently unreliable metric. J Clin Anesth. 2017;42:88-92 pubmed publisher
    ..The implication of the current study is generalizability of that finding from the largest teaching hospital in the state to the other hospitals in the state. ..
  37. Dexter F, Ledolter J, Hindman B. Validity of using a work habits scale for the daily evaluation of nurse anesthetists' clinical performance while controlling for the leniencies of the rating anesthesiologists. J Clin Anesth. 2017;42:63-68 pubmed publisher
    ..1%). Reporting OPPE metrics are mandatory for the maintenance of clinical privileges of anesthesia practitioners in the USA. Basing such peer review on work habits can be quantitative, psychometrically reliable, and valid. ..
  38. Dexter F, Epstein R, Fahy B, Van Swol L. With directed study before a 4-day operating room management course, trust in the content did not change progressively during the classroom time. J Clin Anesth. 2017;42:57-62 pubmed publisher
  39. O Neill L, Dexter F, Park S, Epstein R. Discharges with surgical procedures performed less often than once per month per hospital account for two-thirds of hospital costs of inpatient surgery. J Clin Anesth. 2017;41:99-103 pubmed publisher
    ..The finding that such uncommon procedures account for a large percentage of costs is important because methods of cost accounting by procedure are generally unsuitable for them. ..
  40. O Neill L, Dexter F, Park S, Epstein R. Uncommon combinations of ICD10-PCS or ICD-9-CM operative procedure codes account for most inpatient surgery at half of Texas hospitals. J Clin Anesth. 2017;41:65-70 pubmed publisher
  41. Dexter F, Epstein R, Wachtel R, Rosenberg H. Estimate of the relative risk of succinylcholine for triggering malignant hyperthermia. Anesth Analg. 2013;116:118-22 pubmed publisher
    ..We determine the magnitude of the relative risk of the administration of succinylcholine for triggering MH...