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F Dexter

Publications and source records attributed to F Dexter.

At least 19 recordsLinked to original sources
PubMed2005

[Allocating and scheduling operating room time].

During the past decade many scientific advances have been made concerning the development of methodologies to maximize efficiency of surgical facilities through allocating and scheduling of operating rooms. In this article such a methodology is described. Using the analysis of historical data of surgical activity in a facility, future demand is predicted and planned. Part of the methodology includes principles and rules needed for the daily organization and operative management of surgical facilities. They are also derived from the same science and therefore the basis for rational and structured decision making. Medical aspects such as patient safety and free choice of day for surgery have higher priority than the economic goal of maximizing operating room efficiency.

Efficiency, Organizational↗
PubMed2001

Optimal number of beds and occupancy to minimize staffing costs in an obstetrical unit?

PURPOSE: We describe how the science of analyzing patient arrival and discharge data can be used to determine the optimal number of staffed OB beds to minimize labour costs. METHODS: The number of staffed beds represents a balance between having as few staffed beds as possible to care properly for parturients vs having enough capacity to assure available staff for new admissions. The times of admission and discharge of patients from the OB unit can be used to calculate an average census. From this average census, and the properties of the Poisson distribution, the optimal number of staffed beds can be estimated. This calculation requires specification of the risk of having all in-house and on-call staff caring for patients, such that additional staff are unavailable should another parturient arrive. As an example, patient admission and discharge times were obtained for 777 successive patients cared for at an obstetrical unit. The numbers of patients present in the OB unit each two-hour period were calculated and analyzed statistically. PRINCIPAL FINDINGS: There was variation in the average census among hours of the day and days of the week. Poisson distributions fit the data for each of four periods throughout the week. Simply benchmarking the current average occupancy and comparing it to a desired occupancy would have been inadequate as this neglected consideration of the risk of being unable to appropriately care for an additional patient. CONCLUSIONS: The optimal number of beds and occupancy of an OB unit to minimize staffing costs can be determined using straightforward statistical methods.

Anesthesia, Obstetrical↗
PubMed2001

Weekend operating room on call staffing requirements.

This article describes a statistical method used to determine the minimum number of OR teams that should be on call for urgent procedures, in-house versus on standby from home, to minimize labor costs. The OR manager obtains the number of ORs staffed at each hour of the 24-hour period of interest (e.g., 7 AM Saturday to 7 AM Sunday) from the surgical suite's information system. The minimum number of total staffed hours needed to care for patients is calculated for a prespecified level of the acceptable risk of inadequate staffing. A method used to determine whether each staff member should work in-house or on standby from home then is introduced. This method enumerates all possible combinations of shifts to find the one with the lowest cost, and it ensures a prespecified service level. An example based on 248 weeks of data collected from a large surgical suite is presented, and staffing for emergency procedures is reviewed.

Costs and Cost Analysis↗
PubMed2001

Reducing family members' anxiety while waiting on the day of surgery: systematic review of studies and implications of HIPAA health information privacy rules.

STUDY OBJECTIVE: To investigate changes that most surgical suites will need to make in the process of giving reports to family members on the day of surgery by the compliance date (April 14, 2003) of the privacy regulations of the Health Insurance Portability and Accountability Act (HIPPA) of 1996. DESIGN: Systematic review of the medical literature on ways in which providing information to family members changes their anxiety. MEASUREMENTS: The endpoints of the controlled studies included Spielberger State Anxiety. The observational studies reported percentages of family members with a specific concern. MAIN RESULTS: An in-person progress report can reduce family members' anxiety, but this is not always. A personal approach is superior to providing pagers or a phone call. Observational studies suggest that family members want information specific to their relative, particularly if the case is running later than expected. Statistical methods exist to provide such an estimate of the time remaining in surgical cases. CONCLUSIONS: Surgical facilities should strive to provide in-person progress reports to family members while their relatives are undergoing surgery. To satisfy HIPAA regulations, the staff and physicians who talk to family members in the waiting room will need to determine first if the patient has agreed to the release of information. As hospital information systems are updated to assure that this process is HIPAA-compliant, facilities can also incorporate the relevant statistical methods.

Anxiety↗
PubMed2001

Cost identification analysis for succinylcholine.

UNLABELLED: The cost of a dose of succinylcholine from society's perspective equals the acquisition cost of the drug plus the cost of its adverse outcomes. We hypothesized that although the acquisition cost of succinylcholine is minimal, the true cost would be much larger. We reviewed the medical literature to identify the total cost of a dose of succinylcholine when administered for nonemergency purposes according to manufacturers' guidelines (i.e., to adults only). We found that 88% of the cost per dose of succinylcholine was for the chance of dying or sustaining permanent brain injury from anaphylactic or anaphylactoid reactions to succinylcholine. Consequently, the estimated cost per dose of succinylcholine was sensitive to the incidence of anaphylactic or anaphylactoid reactions to succinylcholine, the risk of severe injury from anaphylactic or anaphylactoid reactions, and the financial value of unforeseen instant death or permanent brain injury. The range for the cost per dose of succinylcholine was thus large, $9 to $93. Our best estimate of the cost per dose was $37. We conclude that the true cost per dose of succinylcholine from society's perspective is more than 20 times the acquisition cost. However, a precise costing requires better knowledge of the incidence and consequences of anaphylactic or anaphylactoid reactions to succinylcholine. IMPLICATIONS: The true cost of succinylcholine is more than 20 times the acquisition cost of the drug. The estimated cost is very sensitive to the risk and cost of patients dying or sustaining brain injury from anaphylactic or anaphylactoid reactions to succinylcholine.

Anaphylaxis↗
PubMed2001

Scheduling a delay between different surgeons' cases in the same operating room on the same day using upper prediction bounds for case durations.

UNLABELLED: At some surgical suites, elective cases are only scheduled if they can be completed during regularly scheduled hours. At such a surgical suite, a surgeon may be scheduled to perform one or more cases in an operating room (OR), to be followed by another surgeon who will perform one or more cases. Scheduling a delay between the two surgeons' cases will improve the likelihood that the second surgeon's case(s) will start on time. We show that the mathematics of calculating a scheduled delay between the different surgeons' cases in the same OR on the same day is that of calculating an upper prediction bound for the duration of the second surgeon's case(s). We test an analytical expression for the upper prediction bound for the last one case of the day in an OR, and a Monte Carlo simulation method for the last two cases. We show that these 90% upper prediction bounds are at least as long as the actual durations for 90% +/- 0.2% of single cases and 92% +/- 0.6% of pairs of cases. We conclude that our methodology can be used to calculate an appropriate, and reasonably accurate, scheduled delay between two surgeons' cases in the same OR on the same day. IMPLICATIONS: We show how to use a statistical analysis of historical case duration data to calculate an appropriate and accurate scheduled delay between two surgeons' cases in the same operating room on the same day.

Algorithms↗
PubMed2001

The impact on revenue of increasing patient volume at surgical suites with relatively high operating room utilization.

UNLABELLED: We previously studied hospitals in the United States of America that are losing money despite limiting the hours that operating room (OR) staff are available to care for patients undergoing elective surgery. These hospitals routinely keep utilization relatively high to maximize revenue. We tested, using discrete-event computer simulation, whether increasing patient volume while being reimbursed less for each additional patient can reliably achieve an increase in revenue when initial adjusted OR utilization is 90%. We found that increasing the volume of referred patients by the amount expected to fill the surgical suite (100%/90%) would increase utilization by <1% for a hospital surgical suite (with longer duration cases) and 4% for an ambulatory surgery suite (with short cases). The increase in patient volume would result in longer patient waiting times for surgery and more patients leaving the surgical queue. With a 15% reduction in payment for the new patients, the increase in volume may not increase revenue and can even decrease the contribution margin for the hospital surgical suite. The implication is that for hospitals with a relatively high OR utilization, signing discounted contracts to increase patient volume by the amount expected to "fill" the OR can have the net effect of decreasing the contribution margin (i.e., profitability). IMPLICATIONS: Hospitals may try to attract new surgical volume by offering discounted rates. For hospitals with a relatively high operating room utilization (e.g., 90%), computer simulations predict that increasing patient volume by the amount expected to "fill" the operating room can have the net effect of decreasing contribution margin (i.e., profitability).

Computer Simulation↗
PubMed2001

A statistical analysis of weekday operating room anesthesia group staffing costs at nine independently managed surgical suites.

UNLABELLED: At many surgical suites, surgeons and patients schedule elective cases on whatever future workday they choose, resulting in there being no limit on the number of cases performed each day. Staff are then scheduled in the manner that satisfies the marketing guarantee to the surgeons, satisfies labor contracts, and minimizes staffing costs. We assessed weekday nurse anesthesia group staffing at nine such suites to determine whether statistical methods can identify staffing solutions whereby all the cases are covered but for which staffing costs are less than those obtained using the staffing plans implemented by anesthesia groups' managers. Two years of operating room information system case duration and staffing data were analyzed. First- and second-shift staffing was assessed using previously published algorithms. The statistical methods identified staffing solutions with significantly decreased labor costs than those currently being used at eight of the nine surgical suites. The statistical methods relied more on overtime than second-shift staffing. The incremental decrease in staffing costs achievable by using overlapping 8-, 10-, and 13-h shifts was negligible. Overall, we found that statistical methods can identify, for some surgical suites, staffing solutions whereby all the cases are covered but for which costs are significantly less and productivity significantly more than those obtained using the plans developed by the managers based on their experience and the data. IMPLICATIONS: Statistical methods can identify, for some surgical suites, anesthesia staffing solutions whereby all the cases are covered but for which labor costs are significantly less than those obtained using the staffing plans developed by the managers based on data and their experience.

Anesthesia↗
PubMed2001

Hospital profitability per hour of operating room time can vary among surgeons.

The operating margins (i.e., profits) of hospitals are decreasing. An important aspect of a hospital's finances is the profitability of individual surgical cases, which is measured by contribution margin. We sought to determine the extent to which contribution margin per hour of operating room (OR) time can vary among surgeons. We retrospectively analyzed 2848 elective cases performed by 94 surgeons at the Stanford University School of Medicine. For each case, we subtracted variable costs from the total payment to the hospital to compute contribution margin. We found moderate variability in contribution margin per hour of OR time among surgeons, relative to the variability in contribution margins per OR hour among each surgeon's cases (Cohen's f equaled 0.29, 95% lower confidence interval bound 0.27). Contribution margin per OR hour was negative for 26% of the cases. These results have implications for hospitals for which OR utilization is extensive, and for which elective cases are only scheduled if they can be completed during regularly scheduled hours. To increase or achieve profitability, managers need to increase the hours of lucrative cases, rather than encourage surgeons to do more and more cases. Whether the variability in contribution margin among surgeons should be used to more optimally (profitably) allocate OR time depends on the scheduling objectives of the surgical suite.

Aged↗
PubMed2001

Brain expression of inducible cyclooxygenase 2 messenger RNA in rats undergoing cardiopulmonary bypass.

BACKGROUND: We hypothesized that systemic proinflammatory cytokines or endotoxemia, or both, associated with cardiopulmonary bypass (CPB) would increase expression of inducible cyclooxygenase (COX-2) or inducible nitric oxide synthase (iNOS) messenger RNA (mRNA), or both, in brain. METHODS: Isoflurane-anesthetized Sprague-Dawley rats were randomly selected for CPB (n = 6) or sham surgery (n = 6). All animals underwent tracheotomy and controlled ventilation, arterial and venous pressure monitoring, insertion of a jugular venous outflow catheter, insertion of a subclavian arterial inflow catheter, systemic anticoagulation (500 U/kg heparin) and, except during CPB, servoregulation of pericranial temperature at 37.5 degrees C. Animals selected for CPB underwent 1 h of CPB at 165 ml x kg(-1) x min(-1) (31.8 +/- 0.2 degrees C), whereas animals having sham surgery underwent no intervention during this interval. Thereafter, all animals were given protamine and remained anesthetized for 4 more h. Brain and liver COX-2 and iNOS mRNA expression were determined by a ribonuclease protection assay with ribosomal L32 mRNA as a loading control. Arterial blood was analyzed for interleukin 1beta, interleukin 6, and endotoxin concentrations. RESULTS: Endotoxin concentrations did not increase above baseline values in either group. At 4 h after the CPB interval, interleukin 6 concentrations were significantly greater in CPB animals (101 +/- 45 pg/ml) versus sham animals (44 +/- 17 pg/ml) (P = 0.025). Brain COX-2 expression was significantly greater in CPB animals (0.36 +/- 0.11) versus shams (0.19 +/- 0.08) (P = 0.013). Brain COX-2 expression correlated with interleukin 6 concentration 4 h after CPB (r = 0.91; P = 5 x 10(-5)). In brain, iNOS mRNA was not detected in any animal. Cardiopulmonary bypass animals had only trace COX-2 and iNOS mRNA induction in liver. CONCLUSIONS: Cardiopulmonary bypass was associated with increased systemic interleukin 6 concentrations and increased brain COX-2 expression.

Anesthesia, Inhalation↗
PubMed2001

Relative value guide basic units in operating room scheduling to ensure compliance with anesthesia group policies for surgical procedures performed at each anesthetizing location.

Many anesthesia groups provide services in a spectrum of anesthetizing locations, including offices, free-standing ambulatory surgery centers, diagnostic clinics, and traditional hospital operating rooms. The use of a uniformly understood measure of case complexity could assist an anesthesia group in ensuring appropriate anesthesia provider expertise and equipment availability at each anesthetizing location. In this article, we show how the American Society of Anesthesiologists' Relative Value Guide (ASA RVG) basic units can be used as a criterion to establish the maximum level of complexity of cases performed at each location by an anesthesia group. By reviewing ASA RVG basic units at several anesthetizing locations in lowa, we found that ASA RVG basic units differ among sites. The ASA RVG basic units can be used to identify cases that are seemingly unexpected for an anesthetizing location. There are several reasonable values that an anesthesia group can use for its maximum number of basic units at an anesthetizing location.

Ambulatory Surgical Procedures↗
PubMed2000

Post-ischemic RSR13 amplifies the effect of dizocilpine on outcome from transient focal cerebral ischemia in the rat.

In a recent study of focal cerebral ischemia in rats, pre-ischemic administration of the synthetic allosteric hemoglobin modifier RSR13 (2-[4-[[3,5-dimethylanilino) carbonyl] methyl] phenoxy]-2-methylproprionic acid) reduced cerebral infarct size when combined with the NMDA receptor antagonist dizocilpine (MK-801) but not when given alone. We hypothesized that post-ischemic RSR13 administration would enhance neuroprotection afforded by NMDA receptor antagonism in a rat model of transient middle cerebral artery occlusion (MCAO). Fasted normothermic Wistar rats underwent 75 min of temporary MCAO. At onset of reperfusion, rats randomly received: (1) 0.9% NaCl (vehicle) i.v. alone (n=16); (2) 0.9% NaCl+dizocilpine (0.25 mg/kg) i.v. (n=16); or (3) RSR13 (150 mg/kg)+dizocilpine (0.25 mg/kg) i.v. (n=17). Seven days later, neurologic deficit and cerebral infarct size were determined. Dizocilpine alone compared to vehicle reduced mean+/-S.D. subcortical (52+/-24 mm(3) vs. 122+/-64 mm(3), P=0.003) and cortical (35+/-35 mm(3) vs. 125+/-72 mm(3), P=0.00074) infarct volumes. When compared to dizocilpine alone, the combination of RSR13+dizocilpine further reduced subcortical (37+/-14 mm(3) vs. 52+/-24 mm(3), P=0. 034) and cortical (8+/-19 mm(3) vs. 35+/-35 mm(3), P=0.018) infarct size. RSR13+dizocilpine improved neurologic scores vs. either dizocilpine alone (P=0.0014) or vehicle (P=10(-7)). The combination of NMDA receptor antagonism and a RSR13 mediated rightward shift of the oxy-hemoglobin dissociation curve improved outcome from MCAO. Because this occurred after reperfusion, our results suggest that the post-ischemic brain continues to suffer from hypoperfusion defects, which are amenable to therapy by enhanced O(2) delivery. The results also support the concept that neuroprotective strategies, which combine drugs with different mechanisms of action, may yield cumulative benefits.

Aniline Compounds↗
PubMed2000

Effect of compensation and patient scheduling on OR labor costs.

To determine whether to accept a contract to provide additional surgical cases, OR managers must determine the incremental costs of caring for the new patients. The expected profitability of the contract can be computed by subtracting the incremental costs from the revenue. For surgical procedures, the incremental costs of OR labor significantly depend on how employees are paid (e.g., part-time versus full-time). If a surgical suite employs full-time staff members, incremental labor costs also are affected by how the day and time of patients' cases are selected (e.g., whether new cases are scheduled weeks in advance by the surgeon and the patient, or are performed on short notice based on the discretion of the surgical suite). This article explains how to estimate the incremental costs of staffing an OR for a case and discusses the use of internet-based online exchanges to match demand for OR time for additional cases to available unused OR capacity in variety of surgical suites.

Appointments and Schedules↗
PubMed2000

Sequencing cases in the operating room: predicting whether one surgical case will last longer than another.

UNLABELLED: A microscope will be used for the first case of the day in operating room (OR) 1 and then may be used in the second case of the day by a different surgeon in a different OR, OR 2. Provided that the probability is reasonably high that the first case of the day in OR 2 will last longer than the first case in OR 1, the OR manager can be confident in scheduling the microscope to be used by both surgeons on the same day. The OR manager can use statistical decision theory to sequence cases to decrease the impact of limitations in equipment or personnel on case scheduling. This increases utilization of both the capital equipment and OR time. In this study, we derived equations that can be programmed into a surgical services information system to reliably estimate the probability that one case will have a longer duration than another. We confirmed the accuracy of our method by using actual case duration data. IMPLICATIONS: Our statistical method uses historical case duration data from an operating room information system to estimate the actual probability to within 1.5% that the second case of a pair will last longer than the first case of a pair.

Appointments and Schedules↗
PubMed2000

Scheduling surgical cases into overflow block time- computer simulation of the effects of scheduling strategies on operating room labor costs.

UNLABELLED: "Overflow" block time is operating room (OR) time for a surgical group's cases that cannot be completed in the regular block time allocated to each surgeon in the surgical group. Having such overflow block time increases OR utilization. The optimal way to schedule patients into a surgical group's overflow block time is unknown. In this study, we developed a scheduling strategy that balances the OR manager's need to reduce staffing costs and the needs of patients and surgeons for flexibility in choosing the dates and times of cases. We used computer simulation to evaluate our scheduling strategy. Surgeons and patients (i) can schedule the case into any overflow block within 2 wk; (ii) can only schedule the case into a "first case of the day" start time more than 2 wk in the future if there is not enough open time for the case within 2 wk; (iii) must schedule the case to be done within 4 wk; and (iv) are encouraged to perform the case on the earliest possible date. Staffing costs were lowest when the OR manager did not incorporate surgeon and patient preferences when scheduling cases into overflow block time. The strategy we developed provides surgeons and patients with some flexibility in scheduling, while only increasing OR staffing costs slightly over the minimum achieved when the OR manager controls scheduling. IMPLICATIONS: The strategy we developed provides surgeons and patients with some flexibility in scheduling, while increasing OR staffing costs only slightly over the minimum achieved when the OR manager controls scheduling. Staffing costs were lowest when the operating room (OR) manager did not incorporate surgeon and patient preferences when scheduling cases into overflow block time.

Appointments and Schedules↗