Effect of a non-reactive absorbent with or without environmentally oriented electronic feedback on anesthesia provider's fresh gas flow rates: A greening initiative.

STUDY OBJECTIVE: To examine the effects of a non-reactive carbon dioxide absorbent (AMSORB® Plus) versus a traditional carbon dioxide absorbent (Medisorb™) on the FGF used by anesthesia providers and an electronic educational feedback intervention using Carestation™ Insights (GE HealthCare) on provider-specific change in FGF. DESIGN: Prospective, single-center cohort study set in a greening initiative. SETTING: Operating room. PARTICIPANTS: 157 anesthesia providers (i.e., anesthesiology trainees, certified registered nurse anesthetists, and solo anesthesiologists). INTERVENTIONS: Intervention #1 was the introduction of AMSORB® Plus into 8 Aisys CS2, Carestation™ Insights-enabled anesthesia machines (GE HealthCare) at the study site. At the end of week 6, anesthesia providers were educated and given an environmentally oriented electronic feedback strategy for the next 12 weeks of the study (Intervention #2) using Carestation™ Insights data. MEASUREMENTS: The dual primary outcomes were the difference in average daily FGF during maintenance anesthesia between machines assigned to AMSORB® Plus versus Medisorb™ and the provider-specific change in average fresh gas flows after 12 weeks of feedback and education compared to the historical data. MAIN RESULTS: Over the 18-week period, there were 1577 inhaled anesthetics performed in the 8 operating rooms (528 for intervention 1, 1049 for intervention 2). There were 1001 provider days using Aisys CS2 machines and 7452 provider days of historical data from the preceding year. Overall, AMSORB® Plus was not associated with significantly less FGF (mean - 80 ml/min, 97.5% confidence interval - 206 to 46, P = .15). The environmentally oriented electronic feedback intervention was not associated with a significant decrease in provider-specific mean FGF (-112 ml/min, 97.5% confidence interval - 244 to 21, P = .059). CONCLUSIONS: This study showed that introducing a non-reactive absorbent did not significantly alter FGF. Using environmentally oriented electronic feedback relying on data analytics did not result in significantly reduced provider-specific FGF.

Propofol Inhibits Glioma Stem Cell Growth and Migration and Their Interaction with Microglia via BDNF-AS and Extracellular Vesicles.

Glioblastoma (GBM) is the most common and aggressive primary brain tumor. GBM contains a small subpopulation of glioma stem cells (GSCs) that are implicated in treatment resistance, tumor infiltration, and recurrence, and are thereby considered important therapeutic targets. Recent clinical studies have suggested that the choice of general anesthetic (GA), particularly propofol, during tumor resection, affects subsequent tumor response to treatments and patient prognosis. In this study, we investigated the molecular mechanisms underlying propofol's anti-tumor effects on GSCs and their interaction with microglia cells. Propofol exerted a dose-dependent inhibitory effect on the self-renewal, expression of mesenchymal markers, and migration of GSCs and sensitized them to both temozolomide (TMZ) and radiation. At higher concentrations, propofol induced a large degree of cell death, as demonstrated using microfluid chip technology. Propofol increased the expression of the lncRNA BDNF-AS, which acts as a tumor suppressor in GBM, and silencing of this lncRNA partially abrogated propofol's effects. Propofol also inhibited the pro-tumorigenic GSC-microglia crosstalk via extracellular vesicles (EVs) and delivery of BDNF-AS. In conclusion, propofol exerted anti-tumor effects on GSCs, sensitized these cells to radiation and TMZ, and inhibited their pro-tumorigenic interactions with microglia via transfer of BDNF-AS by EVs.

Sequential Organ Failure Assessment (SOFA) Score and Mortality Prediction in Patients With Severe Respiratory Distress Secondary to COVID-19.

Background This study looks at the validity of the sequential organ failure assessment score (SOFA) in detecting mortality in patients with Coronavirus disease of 2019 (COVID-19) pneumonia. Also, it is looking to determine the optimal SOFA score that will discriminate between mortality and survival. Methods It is a retrospective chart review of the patients admitted to Henry Ford Hospital from March 2020 to December 2020 with COVID-19 pneumonia who developed severe respiratory distress. We collected the following information; patient demographics (age, sex, body mass index), co-morbidities (history of diabetes mellitus, chronic kidney disease, chronic obstructive pulmonary disease, coronary artery disease, or cancer), SOFA scores (the ratio of arterial oxygen tension (PaO2) to the fraction of inspired oxygen, Glasgow Coma Scale (GCS) score, mean arterial pressure, serum creatinine level, bilirubin level, and platelet count) as well as inpatient mortality. Results There were 320 patients; out of these, 111 were intubated. The receiver operating characteristic (ROC) curve for SOFA at the moment of inclusion in the study had an area under the curve of 0.883. The optimal point for discrimination between mortality and survival is SOFA of 5. A SOFA score of less than two is associated with 100% survival, while a score of more than 11 is associated with 100% mortality. Conclusions SOFA score in COVID-19 patients with severe respiratory distress strongly correlates with the initial SOFA score. It is a valuable tool for predicting mortality in COVID-19 patients.

Characteristics of Organ Donors Who Died From Suicide by Hanging in Australia and New Zealand: A Retrospective Study.

Background and objective The annual incidence of suicide by hanging in Australia and New Zealand has increased in the past decade, and a significant number of these individuals are becoming organ donors. The rates of organ donation following deaths from hanging is unknown and the characteristics of this cohort of donors have not been described in the literature. In light of this, we aimed to examine the trends in organ donation from individuals who had died from hanging, based on the solid organ donor data from the Australia and New Zealand Organ Donation (ANZOD) Registry. Methods We conducted a retrospective study that analyzed the ANZOD Registry donor data (2006-2015) to describe the characteristics of solid organ donors who had died by hanging (post-hanging group); these characteristics were compared to those of individuals who died by all other causes (non-hanging group). Results During the study period, the number and proportion of donors who died by suicide from hanging increased. Of the 4,024 consented organ donors, 226 had died by hanging and 3,798 had died from other causes. The probability that an individual who died by hanging would become an organ donor increased from 0.5 to 3%. Compared to donors who died by all other causes, post-hanging donors were younger (median age of 30 vs. 50 years), with fewer comorbidities, and a higher incidence of smoking. There was no significant difference in the proportion of those who indicated a prior intent to donate organs between post-hanging (34%) and non-hanging donors (38%). A higher proportion of post-hanging donors donated via the donation after the circulatory death pathway (36.3%) than non-hanging donors (24.2%). Individuals in the post-hanging cohort donated an average of 4.19 organs compared to 3.62 in the non-hanging cohort. Conclusion We believe the findings of this retrospective analysis will help inform clinical decision-making regarding organ donation, including the best approaches to obtaining donation consent. Our findings will help physicians provide care to patients and to families of individuals in this challenging group, where organ donation potential is high. Further investigations are required to determine which aspects of healthcare influence the donation rates in individuals who have died by hanging and the outcomes related to transplanted organs.

Hemodynamic Changes with 1:1000 Epinephrine on Wrung-Out Pledgets Before and During Sinus Surgery.

BACKGROUND: Intranasal topical 1:1000 epinephrine has been used safely and effectively for hemostasis during endoscopic sinus surgery (ESS). Prior studies assessing hemodynamic changes after intranasal topical epinephrine application have only used soaking wet cottonoid pledgets, and have only assessed for hemodynamic changes before any surgery being performed. OBJECTIVE: The purposes of this study were to determine whether intranasal application of topical 1:1000 epinephrine with wrung-out cottonoid pledgets caused significant hemodynamic changes both before and during ESS, and whether it allowed for adequate hemostasis. METHODS: A prospective evaluation of 30 patients with eosinophilic chronic rhinosinusitis with nasal polyps (CRSwNP) undergoing complete bilateral ESS was conducted. Heart rate, blood pressure (systolic, diastolic, and mean arterial pressure), and electrocardiography changes were recorded at 0, 1, 2, and 5-minute intervals after placing wrung-out epinephrine-saturated pledgets, both before and at the end of ESS. No submucosal epinephrine injections were performed. Estimated blood loss (EBL) and major intraoperative complications were recorded for all cases. RESULTS: There were no significant hemodynamic changes or electrocardiographic abnormalities after placement of wrung-out epinephrine-soaked pledgets both before and after ESS. After bilateral ESS, there were actually mean decreases in heart rate and blood pressure parameters. Mean EBL was 75.8 ± 32.2 mL, and no major intraoperative complications occurred. CONCLUSION: Intranasal application of topical 1:1000 epinephrine via wrung-out cottonoid pledgets was effective for intraoperative hemostasis, and did not cause clinically significant alterations in hemodynamic parameters or cardiovascular events, either before or during ESS in patients with CRSwNP.Level of Evidence: 4.

Frequency and Analysis of Unplanned Extubation in Coronavirus Disease 2019 Patients.

OBJECTIVES: To determine if patients with coronavirus disease 2019 had a greater number of unplanned extubations resulting in reintubations than in patients without coronavirus disease 2019. DESIGN: Retrospective cohort study comparing the frequency of unplanned extubations resulting in reintubations in a group of coronavirus disease 2019 patients to a historical (noncoronavirus disease 2019) control group. SETTING: This study was conducted at Henry Ford Hospital, an academic medical center in Detroit, MI. The historical noncoronavirus disease 2019 patients were treated in the 68 bed medical ICU. The coronavirus disease 2019 patients were treated in the coronavirus disease ICU, which included the 68 medical ICU beds, 18 neuro-ICU beds, 32 surgical ICU beds, and 40 cardiovascular ICU beds, as the medical ICU was expanded to these units at the peak of the pandemic in Detroit, MI. PATIENTS: The coronavirus disease 2019 cohort included patients diagnosed with coronavirus disease 2019 who were intubated for respiratory failure from March 12, 2020, to April 13, 2020. The historic control (noncoronavirus disease 2019) group consisted of patients who were admitted to the medical ICU in the year spanning from November 1, 2018 to October 31, 2019, with a need for mechanical ventilation that was not related to surgery or a neurologic reason. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: To identify how many patients in each cohort had unplanned extubations, an electronic medical records query for patients with two intubations within 30 days was performed, in addition to a review of our institutional quality and safety database of reported self-extubations. Medical charts were manually reviewed by board-certified anesthesiologists to confirm each event was an unplanned extubation followed by a reintubation within 24 hours. There was a significantly greater incidence of unplanned extubations resulting in reintubation events in the coronavirus disease 2019 cohort than in the noncoronavirus disease 2019 cohort (coronavirus disease 2019 cohort: 167 total admissions with 22 events-13.2%; noncoronavirus disease 2019 cohort: 326 total admissions with 14 events-4.3%; p < 0.001). When the rate of unplanned extubations was expressed per 100 intubated days, there was not a significant difference between the groups (0.88 and 0.57, respectively; p = 0.269). CONCLUSIONS: Coronavirus disease 2019 patients have a higher incidence of unplanned extubation that requires reintubation than noncoronavirus disease 2019 patients. Further study is necessary to evaluate the variables that contribute to this higher incidence and clinical strategies that can reduce it.

Postoperative Pulmonary Complications in the Morbidly Obese: The Role of Tidal Volume and Type of Abdominal Surgery.

BACKGROUND: The patient who is morbidly obese is not adequately represented in the evidence recommending intraoperative low tidal volume (VT) ventilation. We aimed to explore the association between VT adjusted for ideal body weight (IBW) and the occurrence of postoperative pulmonary complications in subjects who were morbidly obese and undergoing abdominal surgery, as well as its implications on intraoperative ventilatory variables. METHODS: We included 734 subjects with a body mass index of at least 40 kg/m2, undergoing open or laparoscopic abdominal surgery that lasted for at least 120 min. Clinical variables were obtained to estimate the preoperative pulmonary risk as well as intraoperative ventilator data to perform associations. Outcomes were defined by medical billing code diagnoses and oxygen use. All data were collected electronically by using Structured Query Language. RESULTS: The subjects received a mean VT/IBW of 9.41 mL/kg IBW, and postoperative pulmonary complications occurred in 7.5% of the subjects. The occurrence of complications was correlated with the presence of several preoperative risk factors for postoperative pulmonary complications. VT/IBW was not associated with postoperative pulmonary complications. This finding remained present after separating different levels of VT/IBW. In a multivariate analysis, only laparoscopic surgery was an independent protective factor against postoperative pulmonary complications (odds ratio 0.07, 95% CI 0.01-0.55). CONCLUSIONS: VT/IBW was not associated with the occurrence of postoperative pulmonary complications in subjects who were morbidly obese and undergoing prolonged abdominal surgery. Future prospective studies are indicated to guide the optimum ventilation strategy for patients who are morbidly obese.

Late first-case of the day starts do not cause greater minutes of over-utilized time at an endoscopy suite with 8-hour workdays and late running rooms. A historical cohort study.

STUDY OBJECTIVE: We consider the influence of the tardiness of first-case of the day start times on the minutes that rooms finish late for procedural suites with relatively interchangeable rooms and mean workloads ≅ 7 h per room, thus regularly filling 8-hour of allocated time. DESIGN: Historical cohort of N = 331 workdays of data. SETTING: Gastrointestinal endoscopy suite. MAIN RESULTS: By unadjusted analyses, reductions in the number of first-cases of the day starting ≥5 min late were associated with less minutes that the day's cases ended beyond the allocated 8 h. However, there were no significant relationships in adjusted analyses, controlling for the daily total hours of cases and turnovers ("workload") or the daily caseload of elective cases. There also were no significant relationships in adjusted analyses between the minutes of cases ending beyond the allocated 8 h and either the count of cases starting ≥15 min late or the mean minutes of case tardiness. The differences between unadjusted and adjusted results were explained by slight positive associations between the count of first-cases starting ≥5 min late and both the daily workload and caseload. Days with less hours of cases had significantly fewer cases starting near simultaneously at the beginning of the day; the same was true for days with fewer total cases. CONCLUSIONS: For procedural suites with relatively interchangeable rooms and mean workloads ≅ 7 h per room, reducing tardiness of first-case of the day start times does not result in beneficial reductions in over-utilized time. The focus of improving on-time starts for the first-cases of the day should be on services with mean workloads that exceed the minimum scheduled duration of the workday.

Approximate Weight of 1:1000 Topical Epinephrine on Wrung-Out Epinephrine-Soaked Pledgets.

OBJECTIVE: Topical 1:1000 epinephrine solution is commonly applied intranasally with cottonoid pledgets in endoscopic sinonasal surgery for local vasoconstriction and hemostasis. Pledgets are typically submerged in epinephrine solution and applied without measurement. Hemodynamic complications have been reported when pledgets have been saturated and not wrung out. The amount of epinephrine absorbed per pledget has not been studied methodically. The purpose of this study was to determine the amount of topical 1:1000 epinephrine remaining on a cottonoid pledget after wringing out the pledget, to simulate intraoperative application. STUDY DESIGN: Cohort study. SETTING: Tertiary care center. SUBJECTS AND METHODS: Sixty 0.5-in × 3-in cottonoid pledgets were submerged in canisters filled with 1:1000 epinephrine solution (1 mg/mL). Weights of the epinephrine-filled canisters were measured before submerging the pledgets and then after removing and wringing out the pledgets. Measurements were recorded for each pledget after being submerged for 0, 1, and 5 minutes and then wrung out. Mean weights were calculated and compared between the submersion durations. RESULTS: The mean overall weight of epinephrine on a wrung-out pledget was 0.931 mg. Mean weights of epinephrine absorbed onto wrung-out pledgets after submersion for 0, 1, and 5 minutes were 0.914, 0.913, and 0.967 mg, respectively. There were no significant differences in weights based on submersion duration (P = .296). CONCLUSION: Approximately 1 mg of epinephrine was absorbed onto 0.5-in × 3-in cottonoid pledgets when pledgets were wrung out after being submerged in 1:1000 epinephrine, whether being removed from solution immediately or after up to 5 minutes.

Endotracheal tube malposition within the pediatric population: a common event despite clinical evidence of correct placement.

PURPOSE: To ensure that the endotracheal tube (ETT) is ideally placed for proper ventilation, radiographic confirmation of ETT placement is frequently used to supplement clinical examination in the intensive care unit setting. However, fluoroscopy rarely serves the same role during surgery, despite the fact that portable units are often present in the operating room. The purpose of this study was to ascertain the value of fluoroscopy in determining ETT malposition among the pediatric surgical population. METHODS: Chest radiographs from 257 children (age 12 days-12 yr), who presented for a total of 446 individual procedures in the fluoroscopy suite, were studied to determine the incidence of ETTs placed too shallow (above the inferior clavicular border) or too deep (at or below the carina). A logistic regression with outcomes of correct and incorrect was used to analyze the data points. RESULTS: Eighteen percent of all the radiographs showed initial improper ETT placement, despite clinical evidence suggesting the contrary. The peak incidence of malposition, which occurred in patients under one year old, reached 35%. Incidence decreased with advancing age, but remained over 10% until the age of ten. A second attempt at positioning the tube, based on information from the chest radiograph, was successful in 95% of the cases. The remaining 5% required placement of the ETT under continuous fluoroscopic guidance. CONCLUSION: Fluoroscopy, when readily available in the operating room, is a safe and useful technique to ensure proper ETT placement among the pediatric population.

Cord gas analysis, decision-to-delivery interval, and the 30-minute rule for emergency cesareans.

OBJECTIVE: Our primary objective was to examine the relationship between umbilical arterial gas analysis and decision-to-delivery interval for emergency cesareans performed for nonreassuring fetal status to determine if this would validate the 30-minute rule. STUDY DESIGN: For this retrospective cohort study, all cesarean deliveries performed for nonreassuring fetal status from September 2001 to January 2003 were reviewed. A synopsis of clinical information that would have been available to the clinician at the time of delivery and the last hour of the electronic fetal heart rate tracing prior to delivery were reviewed by three different maternal-fetal medicine specialists masked to outcome, who classified each delivery as either emergent (delivery as soon as possible) or urgent (willing to wait up to 30 minutes for delivery) since immediacy of the fetal condition is the key factor affecting the type of anesthesia used. RESULTS: Of 145 cesareans performed for nonreassuring fetal status during this period, 117 patients met criteria for entry, of which 34 were classified as emergent and 83 as urgent. Kappa correlation was 0.35, showing only fair/moderate agreement between reviewers. In the emergent group, general anesthesia was more common (35.3%, 10.8%, p=0.003), and the decision-to-delivery interval was 14 minutes shorter (23.0+/-15.3, 36.7+/-14.9 minutes, p<0.001). Linear regression showed a statistically significant relationship between increasing decision-to-delivery interval and umbilical arterial pH (r=0.22, p=0.02) and base excess (r=0.33, p<0.001) showing that delivery proceeded sooner for most of those with the worst cord gases, with a gradual improvement over time. For the 13 (11%) neonates with cord gases placing them at increased risk for long-term neurologic sequelae, the decision-to-delivery interval was 24.7+/-14.6 minutes (range 6 to 50 minutes), and 3/13 (23%) were classified as urgent rather than emergent. CONCLUSION: Electronic fetal monitoring shows considerable variation in interpretation among maternal-fetal medicine specialists and is not a sensitive predictor of the fetus developing metabolic acidosis. There is no deterioration in cord gas results after 30 minutes, and most neonates delivered emergently or urgently for nonreassuring fetal status even when born after 30 minutes have normal cord gases. The 30-minute rule is a compromise that reflects the time it takes the fetus to develop severe metabolic acidosis, our imprecision in its identification, and its rarity in the presence of nonreassuring fetal monitoring.

Allopregnanolone attenuates N-methyl-D-aspartate-induced excitotoxicity and apoptosis in the human NT2 cell line in culture.

Progesterone modulates gamma-aminobutyric acid and excitatory amino acid neurotransmitter systems and has neuroprotective properties in models of hypoxia-ischemia. This study examined the in vitro effects of allopregnanolone, the active progesterone metabolite, in models of N-methyl-D-aspartate (NMDA)-induced necrosis and apoptosis. Cultured NT2 neurons were exposed to 1 mM NMDA. Lactate dehydrogenase (LDH) release was measured 24 h later. NMDA at a concentration of 1 mM produced a 39 +/- 19% release of total LDH. Exposure to 10 microM allopregnanolone prior to NMDA exposure reduced LDH release by 51% (P = 0.0028). NMDA stimulated apoptotic cell changes defined by terminal dUTP nick-end labeling (TUNEL) and 5,5', 6,6'-tetrachloro-1,1,3,3'-tetra ethlybenzimidazolycarbocyanide iodide staining were reduced to baseline values by both 10 microM allopregnanolone and 100 microM MK-801. Pretreatment with allopregnanolone (0-10 microM) reduced the percentage of TUNEL-positive cells in a dose-dependent manner (EC(50) = 2.7 +/- 0.1 nM). Physiologic concentrations of allopregnanolone provided protection against both necrotic and apoptotic injury induced by NMDA excitotoxicity.

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.

Use of linear programming to estimate impact of changes in a hospital's operating room time allocation on perioperative variable costs.

BACKGROUND: Administrators at hospitals with a fixed annual budget may want to focus surgical services on priority areas to ensure its community receives the best health services possible. However, many hospitals lack the detailed managerial accounting data needed to ensure that such a change does not increase operating costs. The authors used a detailed hospital cost database to investigate by how much a change in allocations of operating room (OR) time among surgeons can increase perioperative variable costs. METHODS: The authors obtained financial data for all patients who underwent outpatient or same-day admit surgery during a year. Linear programming was used to determine by how much changing the mix of surgeons can increase total variable costs while maintaining the same total hours of OR time for elective cases. RESULTS: Changing OR allocations among surgeons without changing total OR hours allocated will likely increase perioperative variable costs by less than 34%. If, in addition, intensive care unit hours for elective surgical cases are not increased, hospital ward occupancy is capped, and implant use is tracked and capped, perioperative costs will likely increase by less than 10%. These four variables predict 97% of the variance in total variable costs. CONCLUSIONS: The authors showed that changing OR allocations among surgeons without changing total OR hours allocated can increase hospital perioperative variable costs by up to approximately one third. Thus, at hospitals with fixed or nearly fixed annual budgets, allocating OR time based on an OR-based statistic such as utilization can adversely affect the hospital financially. 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.

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.