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Franklin Dexter

Publications and source records attributed to Franklin Dexter.

At least 19 recordsLinked to original sources
PubMed2003

Optimizing second shift OR staffing.

In surgical suites when ORs sometimes run late, nurse anesthetists or perioperative nurses may be scheduled to work a second shift to cover procedures. Nurse anesthetists' OR workload in the afternoons can differ from that of perioperative nurses. At the end of long procedures, times to transport and stabilize patients can be considerable. This article shows that optimal second-shift OR staffing is the same for nurse anesthetists and perioperative nurses when assessed using anesthesia billing data and OR information systems data respectively. Managers do not need hospital information systems staff members to provide data from both anesthesia billing and OR information systems to make second-shift staffing decisions. One or the other is adequate.

Hospital Costs↗
PubMed2003

Scheduling of cases in an ambulatory center.

Perhaps the most important thing for an anesthesiologist and OR manager to understand is that there are different systems for OR allocation and case scheduling. We referred to them as Fixed Hours, Any Workday, and Reasonable Time. This understanding makes the OR management literature clear and applicable to all staff members. Most ambulatory centers handle cases on the workday chosen by the patient and surgeon but strive to do the work each day as efficiently as possible. Precisely how to make OR allocation and case scheduling decisions to achieve these objectives have been worked out. Studies show that case scheduling decisions to enhance OR efficiency are practiced in many facilities. In contrast, OR allocation decisions tend to be different than what OR managers do in practice. This means that it is important to apply the statistical methods for allocating OR time.

Ambulatory Care Facilities↗
PubMed2003

Physicians' perceptions of minimum time that should be saved to move a surgical case from one operating room to another: internet-based survey of the membership of the Association of Anesthesia Clinical Directors (AACD).

STUDY OBJECTIVE: Moving the last case of the day from one operating room (OR) to another OR can increase OR efficiency. However, there is a penalty cost for moving a case. The goal of the study was to measure perceptions of the minimum time that needs to be saved for it to be worthwhile to move a case from a late-running OR to another OR. DESIGN: Internet-based survey of the Association of Anesthesia Clinical Directors (AACD) and/or attendees at one of its courses. As subjects completed the computer-assisted survey, answers to test questions were checked immediately to ensure respondents understood the relevant concepts. MEASUREMENTS: Respondents were asked to complete the statement: "I would move the case if I would expect to save ____ hours of overutilized OR time." MAIN RESULTS: 234 E-mail invitations to complete the survey were transmitted. Of that number, 87 completed surveys were returned. Respondents were physicians, mostly from the United States. The 25th, 50th, and 75th percentiles of the penalty cost were 1.0 hour of overutilized OR time. The 95% confidence intervals were 0.5 to 1.0 hour for the 25th percentile, 1.0 to 1.0 hour for the 50th percentile, and 1.0 to 2.0 hours for the 75th percentile. There was no significant correlation between the penalty cost and the number of ORs at the respondent's facility, number of times the survey was submitted until it was completed correctly, or total number of errors in responses. CONCLUSIONS: Members of the AACD perceive the penalty cost for moving a case to be 1 hour.

Anesthesia Department, Hospital↗
PubMed2003

How to release allocated operating room time to increase efficiency: predicting which surgical service will have the most underutilized operating room time.

At many facilities, surgeons and patients choose the day of surgery, cases are not turned away, and staffing is adjusted to maximize operating room (OR) efficiency. If a surgical service has already filled its allocated OR time, but has an additional case to schedule, then OR efficiency is increased by scheduling the new case into the OR time of a different service with much underutilized OR time. The latter service is said to be "releasing" its allocated OR time. In this study, we analyzed 3 years of scheduling data from a medium-sized and a large surgical suite. Theoretically, the service that should have its OR time released is the service expected to have the most underutilized OR time on the day of surgery (i.e., any future cases that may be scheduled into that service's time also need to be factored in). However, we show that OR efficiency is only slightly less when the service whose time is released is the service that has the most allocated but unscheduled (i.e., unfilled) OR time at the moment the new case is scheduled. In contrast, compromising by releasing the OR time of a service other than the one with the most allocated but unscheduled OR time markedly reduces OR efficiency. OR managers can use these results when releasing allocated OR time.

Appointments and Schedules↗
PubMed2003

Operating room utilization alone is not an accurate metric for the allocation of operating room block time to individual surgeons with low caseloads.

INTRODUCTION: Many surgical suites allocate operating room (OR) block time to individual surgeons. If block time is allocated to services/groups and yet the same surgeon invariably operates on the same weekday, for all practical purposes block time is being allocated to individual surgeons. Organizational conflict occurs when a surgeon with a relatively low OR utilization has his or her allocated block time reduced. The authors studied potential limitations affecting whether a facility can accurately estimate the average block time utilizations of individual surgeons performing low volumes of cases. METHODS: Discrete-event computer simulation. RESULTS: Neither 3 months nor 1 yr of historical data were enough to be able to identify surgeons who had persistently low average OR utilizations. For example, with 3 months of data, the widths of the 95% CIs for average OR utilization exceeded 10% for surgeons who had average raw utilizations of 83% or less. If during a 3-month period a surgeon's measured adjusted utilization is 65%, there is a 95% chance that the surgeon's average adjusted utilization is as low as 38% or as high as 83%. If two surgeons have measured adjusted utilizations of 65% and 80%, respectively, there is a 16% chance that they have the same average adjusted utilization. Average OR utilization can be estimated more precisely for surgeons performing more cases each week. CONCLUSIONS: Average OR utilization probably cannot be estimated precisely for low-volume surgeons based on 3 months or 1 yr of historical OR utilization data. The authors recommend that at surgical suites trying to allocate OR time to individual low-volume surgeons, OR allocations be based on criteria other than only OR utilization (e.g., based on OR efficiency).

Computer Simulation↗
PubMed2003

Use of discharge abstract databases to differentiate among pediatric hospitals based on operative procedures: surgery in infants and young children in the state of Iowa.

INTRODUCTION: A pediatric hospital may aim to show governmental agencies, charitable organizations, and philanthropic individuals how its clinical services differ from those of nonpediatric surgical facilities and of other pediatric hospitals. Yet, it is unknown how to use existing databases to quantify where infants and young children undergo surgery, and to use that information to differentiate among facilities. METHODS: Discharge abstracts were used to study inpatient and outpatient operative procedures performed between January and June 2001 in children 0-2 yr old at hospitals or hospital-affiliated outpatient surgery centers in Iowa. RESULTS: Of the 93 facilities performing at least one procedure, the 90 performing 15 or fewer different types of procedures provided surgical care for 80% of procedures. Among procedures performed at these 90 facilities, less than 0.15% were physiologically complex (more than seven American Society of Anesthesiologists' basic units). In contrast, at the larger and smaller pediatric hospitals, the percentages were 26% and 7%, respectively. These pediatric hospitals performed 181 and 73 different types of procedures, respectively; 64% of the physiologically complex procedures performed statewide were performed at the larger pediatric hospital. The smaller pediatric hospital was no more similar to the larger pediatric hospital in its relative volumes of each type of procedure than it was to the other 91 facilities. CONCLUSIONS: Statewide discharge abstract data can be used by a hospital to quantify how its surgical practice differs from that of other hospitals (e.g., to show that it provides a more diverse, comprehensive, and physiologically complex selection of procedures in younger patients).

Adolescent↗
PubMed2003

Labor costs incurred by anesthesiology groups because of operating rooms not being allocated and cases not being scheduled to maximize operating room efficiency.

UNLABELLED: Determination of operating room (OR) block allocation and case scheduling is often not based on maximizing OR efficiency, but rather on tradition and surgeon convenience. As a result, anesthesiology groups often incur additional labor costs. When negotiating financial support, heads of anesthesiology departments are often challenged to justify the subsidy necessary to offset these additional labor costs. In this study, we describe a method for calculating a statistically sound estimate of the excess labor costs incurred by an anesthesiology group because of inefficient OR allocation and case scheduling. OR information system and anesthesia staffing data for 1 yr were obtained from two university hospitals. Optimal OR allocation for each surgical service was determined by maximizing the efficiency of use of the OR staff. Hourly costs were converted to dollar amounts by using the nationwide median compensation for academic and private-practice anesthesia providers. Differences between actual costs and the optimal OR allocation were determined. For Hospital A, estimated annual excess labor costs were $1.6 million (95% confidence interval, $1.5-$1.7 million) and $2.0 million ($1.89-$2.05 million) when academic and private-practice compensation, respectively, was calculated. For Hospital B, excess labor costs were $1.0 million ($1.08-$1.17 million) and $1.4 million ($1.32-1.43 million) for academic and private-practice compensation, respectively. This study demonstrates a methodology for an anesthesiology group to estimate its excess labor costs. The group can then use these estimates when negotiating for subsidies with its hospital, medical school, or multispecialty medical group. IMPLICATIONS: We describe a new application for a previously reported statistical method to calculate operating room (OR) allocations to maximize OR efficiency. When optimal OR allocations and case scheduling are not implemented, the resulting increase in labor costs can be used in negotiations as a statistically sound estimate for the increased labor cost to the anesthesiology department.

Anesthesiology↗
PubMed2003

Managing risk and expected financial return from selective expansion of operating room capacity: mean-variance analysis of a hospital's portfolio of surgeons.

UNLABELLED: Surgeons using the same amount of operating room (OR) time differ in their achieved hospital contribution margins (revenue minus variable costs) by >1000%. Thus, to improve the financial return from perioperative facilities, OR strategic decisions should selectively focus additional OR capacity and capital purchasing on a few surgeons or subspecialties. These decisions use estimates of each surgeon's and/or subspecialty's contribution margin per OR hour. The estimates are subject to uncertainty (e.g., from outliers). We account for the uncertainties by using mean-variance portfolio analysis (i.e., quadratic programming). This method characterizes the problem of selectively expanding OR capacity based on the expected financial return and risk of different portfolios of surgeons. The assessment reveals whether the choices, of which surgeons have their OR capacity expanded, are sensitive to the uncertainties in the surgeons' contribution margins per OR hour. Thus, mean-variance analysis reduces the chance of making strategic decisions based on spurious information. We also assess the financial benefit of using mean-variance portfolio analysis when the planned expansion of OR capacity is well diversified over at least several surgeons or subspecialties. Our results show that, in such circumstances, there may be little benefit from further changing the portfolio to reduce its financial risk. IMPLICATIONS: Surgeon and subspecialty specific hospital financial data are uncertain, a fact that should be taken into account when making decisions about expanding operating room capacity. We show that mean-variance portfolio analysis can incorporate this uncertainty, thereby guiding operating room management decision-making and reducing the chance of a strategic decision being made based on spurious information.

Analysis of Variance↗
PubMed2002

Statistical power analysis to estimate how many months of data are required to identify PACU staffing to minimize delays in admission from ORs.

When each nurse in the Phase I setting is caring for the maximum number of patients allowed by hospital staffing standards (typically 2 per ASPAN standards), patients may have to be held in the OR until a PACU nurse becomes available. Previously, the authors described a statistical method to determine the process of scheduling existing nurses without increasing staffing hours (Dexter et al. Anesth Analg. 92:947-949, 2001). The end result was to minimize the percentage of future workdays during which at least one patient would wait in his or her OR for Phase I PACU admission. In this study, the authors performed a statistical power analysis to determine how many months of PACU workload data are needed to optimize PACU staffing by using this "set covering" algorithm. One year (232 workdays) of data was available from a PACU employing up to 10 nurses working a total of 72 clinical hours a day. The data were divided into 2 subsets. Using the first subset, which varied in size between 20 and 140 days of data, the authors identified the optimal staffing solutions. These solutions were tested on the second subset of data. This process then was repeated thousands of times. There was a marked improvement in the performance of the staffing solutions at preventing "PACU hold" by increasing from 20 to 80 historical workdays of data, a slight but statistically significant improvement between 80 and 100 workdays, but no significant improvement in further increasing the number of workdays of data. PACU nurse managers should use at least 4 months of data when choosing a staffing solution to minimize the chance of patients waiting in ORs for PACU admission. Tampering with PACU staffing more often than every 4 months is unlikely to result in improvements in OR efficiency and may harm recruitment and retention of nursing staff.

Operating Rooms↗
PubMed2002

Calculating a potential increase in hospital margin for elective surgery by changing operating room time allocations or increasing nursing staffing to permit completion of more cases: a case study.

UNLABELLED: Administrators routinely seek to increase contribution margin (revenue minus variable costs) to better cover fixed costs, provide indigent care, and meet other community service responsibilities. Hospitals with high operating room (OR) utilizations can allocate OR time for elective surgery to surgeons based partly on their contribution margins per hour of OR time. This applies particularly when OR caseload is limited by nursing recruitment. From a hospital's annual accounting data for elective cases, we calculated the following for each surgeon's patients: variable costs for the entire hospitalization or outpatient visit, revenues, hours of OR time, hours of regular ward time, and hours of intensive care unit (ICU) time. The contribution margin per hour of OR time varied more than 1000% among surgeons. Linear programming showed that reallocating OR time among surgeons could increase the overall hospital contribution margin for elective surgery by 7.1%. This was not achieved simply by taking OR time from surgeons with the smallest contribution margins per OR hour and giving it to the surgeons with the largest contribution margins per OR hour because different surgeons used differing amounts of hospital ward and ICU time. We conclude that to achieve substantive improvement in a hospital's perioperative financial performance despite restrictions on available OR, hospital ward, or ICU time, contribution margin per OR hour should be considered (perhaps along with OR utilization) when OR time is allocated. IMPLICATIONS: For hospitals where elective surgery caseload is limited by nursing recruitment, to increase one surgeon's operating room time either another surgeon's time must be decreased, nurses need to be paid a premium for working longer hours, or higher-priced "traveling" nurses can be contracted. Linear programming was performed using Microsoft Excel to estimate the effect of each of these interventions on hospital contribution margin.

Elective Surgical Procedures↗
PubMed2002

Operating room managers' use of integer programming for assigning block time to surgical groups: a case study.

UNLABELLED: A common problem at hospitals with fixed amounts of available operating room (OR) time (i.e., "block time") is determining an equitable method of distributing time to surgical groups. Typically, facilities determine a surgical group's share of available block time using formulas based on OR utilization, contribution margin, or some other performance metric. Once each group's share of time has been calculated, a method must be found for fitting each group's allocated OR time into the surgical master schedule. This involves assigning specific ORs on specific days of the week to specific surgical groups, usually with the objective of ensuring that the time assigned to each group is close to its target share. Unfortunately, the target allocated to a group is rarely expressible as a multiple of whole blocks. In this paper, we describe a hospital's experience using the mathematical technique of integer programming to solve the problem of developing a consistent schedule that minimizes the shortfall between each group's target and actual assignment of OR time. Schedule accuracy, the sum over all surgical groups of shortfalls divided by the total time available on the schedule, was 99.7% (SD 0.1%, n = 11). Simulations show the algorithm's accuracy can exceed 97% with > or =4 ORs. The method is a systematic and successful way to assign OR blocks to surgeons. IMPLICATIONS: At hospitals with a fixed budget of operating room (OR) time, integer programming can be used by OR managers to decide which surgical group is to be allocated which OR on which day(s) of the week. In this case study, we describe the successful application of integer programming to this task, and discuss the applicability of the results to other hospitals.

Elective Surgical Procedures↗
PubMed2002

What are the most important risk factors for a patient's developing intraoperative hypothermia?

UNLABELLED: Anesthesiologists attempt to maintain perioperative normothermia for surgical patients. We surveyed clinical anesthesiologists and physician researchers and asked them to prioritize risk factors for a patient to develop intraoperative hypothermia. The questionnaire included 41 factors associated with changes in patient temperature identified during a computerized literature search. We asked respondents to estimate the relative importance of each risk factor on a 10-point scale. The survey was mailed to two groups: 1) 180 anesthesiologists (n = 84 respondents) randomly selected from the 1999 American Society of Anesthesiologists Members Directory and to 2) 24 physician researchers (n = 12 respondents) in thermoregulation. Researchers rated the following to be the most important risk factors for hypothermia (in sequence): neonates, a low ambient operating room temperature, burn injuries, general anesthesia with neuraxial anesthesia, geriatric patients, low temperature of the patient before induction, a thin body type, and large blood loss. The results for the clinician group were similar, because the median differences between the groups' results were two or fewer units for all items. The risk factors identified to be most important can now be further evaluated in clinical trials to develop a multivariate predictive tool for calculating a patient's a priori risk for developing hypothermia. IMPLICATIONS: Surveys of clinicians and physician researchers identified what they consider to be the most important risk factors for perioperative hypothermia (e.g., neonates, a low ambient operating room temperature, burn patients, and general anesthesia with neuraxial anesthesia).

Adult↗
PubMed2002

Statistical power analysis to estimate how many months of data are required to identify operating room staffing solutions to reduce labor costs and increase productivity.

UNLABELLED: We performed a statistical power analysis to determine how many historical data are needed for optimal operating room (OR) management decision making. The work applies to hospitals that provide service for all of its surgeons' elective cases on whatever workday the surgeons and patients choose. The hospital and anesthesia group adjust OR staffing and patient scheduling to care for the patients while minimizing OR staffing costs and maximizing labor productivity. Two years of data were obtained from a seven-OR surgical suite. The data were repeatedly split into training and testing datasets. The optimal staffing solution was calculated for each training dataset to maximize the efficiency of OR time usage and was then applied to the corresponding testing dataset. Training datasets ranged in size from 30 to 270 consecutive workdays. With 30 workdays of data, the statistical method identified staffing solutions that had an average of 35% decreased costs and 27% increased productivity as compared to the existing staffing plan. There was no significant improvement in performance with more than 210 workdays (10 mo) of data. With 30 workdays of OR or anesthesia group data, the optimization method can significantly reduce staffing costs and increase productivity compared with existing staffing. When applied routinely for adjusting staffing (e.g., on a quarterly basis), 9 to 12 mo of data should be used. IMPLICATIONS: With 30 workdays of operating room or anesthesia group data, the optimization method can propose staffing solutions that significantly decrease costs and increase productivity compared with existing staffing solutions. We recommend that, when the statistical method is applied routinely for adjusting staffing (e.g., on a quarterly basis), 9 to 12 mo of data be used.

Efficiency↗
PubMed2002

How to schedule elective surgical cases into specific operating rooms to maximize the efficiency of use of operating room time.

UNLABELLED: We considered elective case scheduling at hospitals and surgical centers at which surgeons and patients choose the day of surgery, cases are not turned away, and anesthesia and nursing staffing are adjusted to maximize the efficiency of use of operating room (OR) time. We investigated scheduling a new case into an OR by using two patient-scheduling rules: Earliest Start Time or Latest Start Time. By using several scenarios, we showed that the use of Earliest Start Time is rational economically at such facilities. Specifically, it maximizes OR efficiency when a service has nearly filled its regularly scheduled hours of OR time. However, Latest Start Time will perform better at balancing workload among services' OR time. We then used historical case duration data from two facilities in computer simulations to investigate the effect of errors in predicting case durations on the performance of these two heuristics. The achievable incremental reduction in overtime by having perfect information on case duration versus using historical case durations was only a few minutes per OR. The differences between Earliest Start Time and Latest Start Time were also only a few minutes per OR. We conclude that for facilities at which the goals are, in order of importance, safety, patient and surgeon access to OR time, and then efficiency, few restrictions need to be placed on patient scheduling to achieve an efficient use of OR time. IMPLICATIONS: We showed how elective cases should be scheduled to maximize the efficiency of use of operating room time. The analysis applies to surgical suites at which surgeons and patients have access to operating room time every workday.

Ambulatory Surgical Procedures↗
PubMed2002

Changing allocations of operating room time from a system based on historical utilization to one where the aim is to schedule as many surgical cases as possible.

UNLABELLED: Many facilities allocate operating room (OR) time based on historical utilization of OR time. This assumes that there is a fixed amount of regularly scheduled OR time, called "block time". This "Fixed Hours" system does not apply to many surgical suites in the US. Most facilities make OR time available for all its surgeons' patients, even if cases are expected to finish after the end of block time. In this setting, OR time should be allocated to maximize OR efficiency, not historical utilization. Then, cases are scheduled either on "Any Workday" (i.e., date chosen by patient and surgeon) or within a reasonable time (e.g., "Four Weeks"). In this study, we used anesthesia billing data from two facilities to study statistical challenges in converting from a Fixed Hours to an Any Workday or Four Weeks patient scheduling system. We report relationships among the number of staffed ORs (i.e., first case of the day starts), length of the regularly scheduled OR workday, OR efficiency, OR staffing cost, and changes in services' OR allocations. These relationships determine the expected changes in each service's OR allocation, when a facility using Fixed Hours considers converting to the Any Workday or Four Weeks systems. IMPLICATIONS: We investigated the complex relationships among the number of surgical services, number of staffed operating rooms (ORs), length of the regularly scheduled OR workday, efficiency of use of OR time, OR staffing cost, and changes in each services' allocated OR time.

Ambulatory Surgical Procedures↗
PubMed2002

Development of an appropriate list of surgical procedures of a specified maximum anesthetic complexity to be performed at a new ambulatory surgery facility.

UNLABELLED: A common but difficult task for a hospital when it decides to open a freestanding ambulatory surgery facility is how to decide which surgical procedures should be done at the new facility. This is necessary in order to determine how many operating rooms to plan for the new facility and which ancillary services are needed on-site. In this case study, we describe a novel methodology that we used to develop a comprehensive list of procedures to be done at a new ambulatory facility. The level of anesthetic complexity of a procedure was defined by its number of ASA Relative Value Guide basic units. Broad categories of procedures (e.g., eye surgery) were defined according to the International Classification of Diseases, Ninth Revision, Clinical Modification. We identified 22 categories that are of a type that every procedure in the category has no more than seven basic units. In addition, by analyzing all procedures that the hospital being studied actually performed on an ambulatory basis, we identified six other categories of procedures that were of a type that all procedures eligible for surgery at the new facility had seven or fewer basic units. IMPLICATIONS: We describe a novel method to develop a comprehensive list of procedures that have a prespecified maximum level of anesthetic complexity to be performed at a new ambulatory surgery facility.

Adolescent↗
PubMed2002

Sampling error can significantly affect measured hospital financial performance of surgeons and resulting operating room time allocations.

UNLABELLED: Hospitals with limited operating room (OR) hours, those with intensive care unit or ward beds that are always full, or those that have no incremental revenue for many patients need to choose which surgeons get the resources. Although such decisions are based on internal financial reports, whether the reports are statistically valid is not known. Random error may affect surgeons' measured financial performance and, thus, what cases the anesthesiologists get to do and which patients get to receive care. We tested whether one fiscal year of surgeon-specific financial data is sufficient for accurate financial accounting. We obtained accounting data for all outpatient or same-day-admit surgery cases during one fiscal year at an academic medical center. Linear programming was used to find the mix of surgeons' OR time allocations that would maximize the contribution margin or minimize variable costs. Confidence intervals were calculated on these end points by using Fieller's theorem and Monte-Carlo simulation. The 95% confidence intervals for increases in contribution margins or reductions in variable costs were 4.3% to 10.8% and 6.0% to 8.9%, respectively. As many as 22% of surgeons would have had OR time reduced because of sampling error. We recommend that physicians ask for and OR managers get confidence intervals of end points of financial analyses when making decisions based on them. IMPLICATIONS: The common approach of using one fiscal year of perioperative accounting data can be insufficient to prevent random error from influencing important management decisions. When accounting data are used for hospital and operating room management decision making, confidence intervals should be calculated for the key financial variables (e.g., variable cost per hour of operating room time).

Costs and Cost Analysis↗