Surgery Start Time Research Articles

WP7.12 - The Impact of a ‘Golden Abscess Pathway’ in a Tertiary Teaching Hospital to Optimize Acute Abscess Management

Abstract Introduction The 'Golden Patient' initiative targets operating room efficiency by pre-selecting initial patients, especially beneficial for non-urgent emergencies like abscesses. Anorectal abscesses often face treatment delays due to the prioritization of critical cases. WSES guidelines advocate prompt incision and drainage (I&D) within 24 hours, recommending outpatient management for suitable patients. This study aims to establish an ambulatory 'Golden Abscess Pathway' in a tertiary teaching hospital and assess its impact on acute abscess management efficiency. Patients and Methods This retrospective study at the Leeds Institute of Emergency General Surgery included individuals undergoing I&D for acute abscesses. The pre-pathway cohort spanned 03/01/2023 to 28/04/2023, with the 'Golden Abscess Pathway' implemented on 19/06/2023. The post-pathway cohort covered 19/06/2023 to 16/10/2023. The analysis focused on patient demographics and intervention timelines. Results The study included 199 patients, with 93 pre-pathway (55M: 38F, mean age 34.3 ± 14.5 years) and 106 post-pathway (70M: 36F, mean age 35.4 ± 13.3 years). The 'Golden Abscess Pathway' reduced the average duration from consultation to operation (1.73 days vs. 2.75 days), advanced median operation start time (09:20 vs. 09:47), and decreased overnight stays (34.9% vs. 44.1%). Conclusion Implementation of the 'Golden Abscess Pathway' demonstrated positive outcomes, reducing delays in patient management. These results highlight the pathway's potential to enhance efficiency and overall patient care in acute abscess management.

Root causes of first-case start time delays for elective surgical procedures: a prospective multicenter observational cohort study in Ethiopia

BackgroundDelays in surgery start times can lead to poor patient outcomes and considerable increases in healthcare expenditures. This is especially true in developing countries that often face systemic inefficiencies, such as a shortage of operating rooms and trained surgical personnel. With substantial effects on patient outcomes, healthcare efficiency, and resource allocation, identifying delays in first-case elective surgery is a crucial area of research.MethodsA multicenter observational study was conducted at three comprehensive and specialized hospitals in the Amhara region of Ethiopia from May 1 to October 30, 2023. The primary aim of the study was to determine the occurrence of late first-case start times, defined as a patient being in the operating room at or after the hospital’s incision time of 2:30 a.m. The secondary aim was to discover potential root causes of delayed first-case start times. All patients scheduled for elective surgery as the first case on the operating list throughout the study period were included in the study. Every emergency, day case, after-hours case, and canceled case was excluded.ResultsA total of 530 surgical patients were included during the study window from May 1 to October 1, 2023. Of these, 41.5% were general surgeries, 20.4% were gynecology and obstetrics surgeries, and 13.2% were orthopedic surgery procedures. Before the procedure started, nine (1.7%) of the participants had prolonged discussion with a member of the surgical team. Patients who arrived in the operating room waiting area at or after 2:30 a.m. were 2.5 times more likely to experience a first-case start time delay than those who arrived before or at 2:00 a.m. (AOR = 2.50; 95% CI: 1.13–5.14). Furthermore, participants with abnormal investigation results were 2.4 times more likely to have a late first-case start time (AOR = 2.41; 95% CI: 1.06, 5.50). Moreover, the odds of a late first-case start time were increased by 10.53 times with the surgeon being in the operating room at or after 2:30 a.m. (AOR = 10.53; 95% CI: 5.51, 20.11).ConclusionThe research highlights a significant occurrence of delayed start times for the first elective surgical procedures. Therefore, directing attention to aspects such as ensuring patients and surgical teams arrive promptly (by or before 2:00 a.m.) and timely evaluation and communication of investigative findings before the scheduled surgery day could facilitate efforts to maximize operating room efficiency and enhance patient health outcomes.

Research on a multiobjective cooperative operation scheduling method for agricultural machinery across regions with time windows

This article aims to solve the problems of high cost, low efficiency, and task delay caused by the lack of scientific scheduling strategies during the agricultural harvest season. Considering the constraints of operation time windows, a multimachine multiobjective cross-regional collaborative operation scheduling model is constructed with the goal of minimizing the transfer distance of agricultural machinery and nonoperational scheduling costs. A multiobjective genetic algorithm (HTSMOGA) based on a hybrid time window priority rule and a tabu search strategy is designed. The initial population is generated by utilizing time window priority rules, genes with earlier operation start times are preferentially retained, and a mixed search strategy is introduced to avoid local optimal solutions. Experiments were conducted among 24 farms in a region of Hebei Province, and the results showed that, compared with other algorithms, the HTSMOGA achieved an average reduction of 17.18 % in the transfer distance of agricultural machine operations and 19.36 % in the nonoperational waiting time. Therefore, this study provides a rational and feasible solution for the cross-regional operation scheduling of agricultural machinery cooperatives and provides theoretical support for ensuring the timely completion of harvesting tasks and the cost savings and efficiency of agricultural machinery operations.

A robust mixed-integer binary programming model for operating theater scheduling to the patient and the surgeon under uncertainty in an open-heart Surgery Department

In hospitals, the surgical ward is both a cost and revenue center. In this ward, hospitals face challenges such as increasing demand, limited resources, and rising costs. Consequently, the decisions made have an implications effect on the hospital's performance. Therefore, in this paper a robust mixed-integer binary programming model is proposed with three objectives of maximizing the efficiency of available resources, minimizing the patients waiting time, and minimizing surgery costs that are formulated utilizing the augmented epsilon constraint approach. This model allocates the operating room to the patient and the surgeon and then obtains the required bed capacity inside the downstream units for stand-alone cardiac hospitals. This model includes different preferences for hospital, surgeon, and patient: waiting time, patient cancellations, tardiness, uncertainties in surgery durations, the patient operation start times, the overtime per working day, time windows, SICU beds, planning horizon, and the idle times of the surgeons, operating theater, and working day. The proposed model is solved using robust optimization to deal with stochastic. The proposed model is formulated on the stochastic programming method proposed by Bertsimas and Sim. In the proposed model, a rolling horizon method is used to reschedule the program after cancellation. The computational results illustrate that the rolling horizon method reduces waiting time and increases throughput. The results illustrate that the benefit obtained from the introduced model has improvements in reducing the surgery costs, and patient waiting time, and increasing the efficiency of available resources. This study has been performed at Shahid Rajaei Heart Hospital in Iran.

Impact of Replacing Fentanyl With Hydromorphone as the First-Line Postoperative Opioid Among Patients Undergoing Outpatient Cancer Surgery

In response to a nationwide fentanyl shortage, our institution assessed whether changing our first-line postoperative intravenous opioid from fentanyl to hydromorphone impacted patient outcomes. The primary research aim was to evaluate the association between first-line opioid and rapidity of recovery. The study team retrospectively obtained data on all consecutive patients extracted from the electronic medical record. The rapidity of recovery was defined as the time from entry into the postanesthesia care unit to the transition to Phase 2 for ambulatory extended recovery patients and as the length of total postanesthesia care unit stay for outpatients. Following intent-to-treat-principles, we tested the association between study period and rapidity of recovery (a priori clinically meaningful difference: 20minutes) using multivariable linear regression, adjusting for anesthesia type (general vs monitored anesthesia care), American Society of Anesthesiologst physical status (ASA) score (1-2 vs 3-4), age, service, robotic procedure, and surgery start time. Ambulatory extended recovery patients treated in the hydromorphone period had, on average, a 0.25minute(95% confidence interval [CI] -6.5, 7.0), nonstatistically significant (P>.9) longer time to transition. For outpatient procedures, those who received hydromorphone had, on average, 8.5-minute longer stays (95% CI 3.7-13, P<.001). Although we saw statistical evidence of an increased risk of resurgery associated with receiving hydromorphone (0.5%; 95% CI -0.1%, 1.0%; P=.039 on univariate analysis), the size of the estimate is clinically and biologically implausible and is most likely a chance finding related either to multiple testing or confounding. The multidisciplinary team concluded that the increase in postoperative length of stay associated with hydromorphone was not clinically significant and the decrease waste of prefilled syringes outweighed the small potential increased risk of resurgery compared to the shorter-acting fentanyl. We will therefore use hydromorphone moving forward.

The effect of surgery started at different time point during the day on the clinical outcomes of mitral valve surgery.

The clinical prognosis of mitral valve surgery at morning, afternoon, and evening is not yet clear. The aim of the study is to investigate the impact of different time periods of surgery in the morning, afternoon and evening on the short-term and long-term results of mitral valve surgery. From January 2018 to December 2020, 947 patients with mitral valve surgery in our department were selected. These patients were divided into 3 groups according to the starting time of surgery. Morning group (operation start time 8:00-10:30, n = 231), afternoon group (operation start time 12:00-14:30, n = 543), and evening group (operation start time 17:30-20:00, n = 173). The short-term and long-term results of the three groups were compared. There were no significant difference in the long-term mortality, long-term risk of stroke and reoperation. And there were no significant difference in in-hospital outcomes, including mortality, stroke, cardiopulmonary bypass time, aortic cross clamp time, mitral valve repair convert to mitral valve replacement, number of aortic cross clamp ≥2 times, unplanned secondary surgery during hospitalization (including thoracotomy hemostasis, thoracotomy exploration, redo mitral valve surgery, and debridement), intra-aortic balloon pump, extracorporeal membrane oxygenation, continuous renal replacement therapy, mechanical ventilation time, and intensive care unit length of stay. There is no significant difference in the risk of short-term and long-term survival and adverse events after mitral valve surgery at different time periods in the morning, afternoon, and evening. Mitral valve surgery at night is safe.

Outpatient Total Joint Arthroplasty at a High-Volume Academic Center: An Analysis of Failure to Launch

BackgroundUnanticipated failure to discharge home (failure to launch, FTL) following scheduled same-day discharge (SDD) total joint arthroplasty (TJA) is problematic for the surgical facility with respect to staffing, care coordination, and reimbursement concerns. The aim of this study was to review rates, etiologies, and contributing factors for FTL in SDD TJA at an inpatient academic medical center. MethodsAll patients who underwent primary TJA between February 2021 and February 2023 were retrospectively reviewed. Of those scheduled for SDD, risk factors for FTL were compared with successful SDD. Readmission and emergency department (ED) visits were compared with historical cohorts. There were 3,093 consecutive primary joint arthroplasties performed, of which 2,411 (78%) were scheduled for SDD. ResultsOverall, SDD was successful in 94.2% (n = 2,272) of patients who had an FTL rate of 5.8%. Specifically, SDD was successful in 91.4% with total hip arthroplasty, 96.0% with total knee arthroplasty, and 98.6% with unicompartmental knee arthroplasty. Factors that significantly increased the risk of FTL included general anesthesia versus spinal anesthesia (P < .0001), later surgery start time (P < .0001), longer surgical time (P = .0043), higher estimated blood loss (P < .0001), women (P = .0102), younger age (P = .0079), and lower preoperative mental health patient-reported outcomes scores (P = .0039). Readmission and ED visit rates were not higher in the SDD group when compared to historical controls (P = .6830). ConclusionsWith a comprehensive multidisciplinary approach dedicated to improving SDDs at an academic medical center, we have seen successful SDD in nearly 80% of primary TJA, with an FTL rate of 5.8%, and no increased risk of readmission or ED visits. Without adding many personnel, hospital recovery units, or other resources, simple interventions to help decrease FTL have included enhanced preoperative education and expectation settings, improved perioperative communications, reallocating personnel from the inpatient to the outpatient setting, the use of short-acting spinal anesthetics, and earlier scheduled surgery times.

Factors influencing same-day discharge after minimally invasive hysterectomy for malignant and non-malignant gynecological diseases: a systematic review and meta-analysis.

To explore the factors influencing the successful implementation of same-day discharge in patients undergoing minimally invasive hysterectomy for malignant and non-malignant gynecological diseases. We searched PubMed, Embase, Cochrane Central Register of Controlled Trials, International Clinical Trials Registry Platform, and Clinical Trials.gov from inception to May 23, 2023. We included case-control and cohort studies published in English reporting same-day discharge factors in patients undergoing minimally invasive hysterectomy for malignant and non-malignant gynecological diseases. STATA 16.0 was used for the meta-analysis. Risk factors were assessed using odds ratios (OR) (relative risk (RR)/hazard ratios (HR)) with 95% confidence intervals (CI), and logistic regression determined the same-day discharge rate (%). We analyzed 29 studies with 218192 patients scheduled for or meeting same-day discharge criteria. The pooled rates were 50% (95% CI 0.46-0.55), and were similar for malignant and non-malignant gynecological diseases (48% and 47%, respectively). In terms of basic characteristics, an increase in age (OR: 1.03; 95% CI: 1.01-1.05), BMI (OR: 1.02; 95% CI: 1.01-1.03), and comorbidities including diabetes and lung disease were risk factors affecting SDD, while previous abdominal surgery history (OR: 1.54; 95% CI: 0.93-2.55) and hypertension (OR: 1.53; 95% CI: 0.80-2.93) appeared not to affect SDD. In terms of surgical characteristics, radical hysterectomy (OR: 3.46; 95% CI: 1.90-6.29), surgery starting after 14:00 (OR: 4.07; 95% CI: 1.36-12.17), longer surgical time (OR: 1.03; 95% CI: 1.01-1.06), intraoperative complications (OR: 4.68; 95% CI: 1.78-12.27), postoperative complications (OR: 3.97; 95% CI: 1.68-9.39), and surgeon preference (OR: 4.47; 95% CI: 2.08-9.60) were identified as risk factors. However, robotic surgery (OR: 0.44; 95% CI: 0.14-1.42) and intraoperative blood loss (OR: 1.16; 95% CI: 0.98-1.38) did not affect same-day discharge. An increase in age, body mass index, and distance to home; certain comorbidities (e.g., diabetes, lung disease), radical hysterectomy, surgery starting after 14:00, longer surgical time, operative complications, and surgeon preference were risk factors preventing same-day discharge. Same-day discharge rates were similar between malignant and non-malignant gynecological diseases. The surgery start time and body mass index have a greater impact on same-day discharge for malignant diseases than non-malignant diseases.

Safety of nighttime elective hepatectomy for hepatocellular carcinoma patients: a retrospective study.

This study aimed to investigate whether nighttime elective surgery influenced the short-term outcomes and prognosis of hepatocellular carcinoma (HCC) patients. The 1,339 HCC patients who underwent hepatectomy were divided into the daytime surgery group (8 a.m.-6 p.m., n = 1,105) and the nighttime surgery group (after 6 p.m., n = 234) based on the start time of surgery. The 1:2 propensity score matching (PSM) analysis was used to control confounding factors. The short-term outcomes of HCC patients in the 2 groups were compared before and after PSM. Factors associated with major complications (Clavien-Dindo grade, ≥III) and textbook oncologic outcomes (TOO) were separately identified by multivariable logistic regression based on variables screened via least absolute shrinkage and selection operator (LASSO). The Kaplan-Meier method was used to analyze overall survival (OS) and recurrence-free survival (RFS). TOO was achieved after surgery in 897 HCC patients. HCC patients in the nighttime surgery group had a higher body mass index (P = 0.010). After 1:2 PSM, the baseline characteristics of patients between the 2 groups were similar. Short-term outcomes in HCC patients were comparable both before and after PSM (all Ps > 0.05), as were TOO in the 2 groups before (P = 0.673) and after PSM (P = 0.333). In our LASSO-logistic regression, nighttime surgery was not an independent factor associated with major complications or TOO. Both groups also had similar OS (P = 0.950) and RFS (P = 0.740) after PSM. Our study revealed the safety of nighttime elective hepatectomy for HCC patients.

The Effects of Daytime Variation on Short-term Outcomes of Patients Undergoing Off-Pump Coronary Artery Bypass Grafting

Study objectiveTo evaluate the effects of time of operation on short-term outcomes of patients undergoing off-pump coronary artery bypass grafting (OPCAB). DesignRetrospective cohort study. SettingA single large-volume cardiovascular center. PatientsPatients undergoing elective OPCAB between September 2019 and July 2022. InterventionsPatients were divided into two groups according to the start time of surgery: morning (AM group, before 11am) and afternoon (PM group, after 11am). Propensity score matching (PSM) with a 1:1 matching ratio was used to create comparable cohorts. Measurements and Main resultsThe primary endpoint was the composite incidence of mortality and morbidities during hospitalization. Secondary endpoints included postoperative bleeding and transfusion, mechanical ventilation duration (MVD) and length of stay (LOS) in intensive care unit (ICU) and hospital. From a consecutive series of 1,039 patients, PSM yielded 317 well-matched pairs. There was no difference in the composite incidence of in-hospital mortality and morbidities between AM and PM groups (16.4% vs. 17.4%, P=0.832). However, patients in PM group were associated with less postoperative blood loss over the first 24 h (470 ml vs. 540 ml, P=0.002), decreased MVD (14 h vs. 16 h, P<0.001) and shorter LOS in ICU (46 h vs. 68 h, P=0.002) as compared to patients in AM group. ConclusionsThe current study suggested a lack of relevance regarding time of operation with in-hospital mortality and morbidities in patients undergoing OPCAB.

Effects of intraoperative sodium oxybate infusion on post-operative sleep quality in patients undergoing gynecological laparoscopic surgery: A randomized clinical trial

Study objectivePost-operative sleep quality is an important factor that influences post-operative recovery. Sodium oxybate has been used to treat sleep disturbances associated with various pathological conditions. However, whether intraoperative intravenous infusion of sodium oxybate improves post-operative sleep quality is unknown. This study aimed to examine the effects of sodium oxybate on the post-operative sleep quality of patients who underwent gynecological laparoscopic surgery. DesignA single-center, prospective, two-arm, double-blinded randomized controlled trial. SettingThe Shengjing Hospital of China Medical University in Liaoning, China. PatientsWe enrolled 180 adult patients (90 for each group) undergoing elective gynecological laparoscopic surgery, and 178 patients (89 for each group) were included in the final analysis. InterventionsPatients were randomly allocated in a 1:1 ratio to receive either sodium oxybate (30 mg kg−1) or an equivalent volume of saline after intubation. The patients, anesthetists, and follow-up staff were blinded to group assignment. MeasurementsThe primary outcome was sleep quality measured using the Richards–Campbell Sleep Questionnaire (RCSQ) on post-operative days (PODs) one and three. Secondary outcomes included post-operative pain measured using the visual analog scale, sleep quality at one and three months post-operatively measured using the Pittsburgh Sleep Quality Index, and factors associated with post-operative sleep quality. Main resultsAnalysis with generalized estimating equations showed that sodium oxybate significantly improved post-operative sleep quality, as represented by increased total RCSQ scores (mean difference (95% CI); 9 (2, 16), P = 0.010) over PODs one and three. There was no difference in post-operative pain between the two groups over PODs one and three or in post-operative sleep quality over one and three months post-operatively. Age, surgery type, start time of surgery, and use of sufentanil-based patient-controlled intravenous analgesia were significantly associated with post-operative sleep quality. ConclusionsIntraoperative sodium oxybate infusion improved post-operative sleep in patients who underwent gynecological laparoscopic surgery.Trial registration.Chinese Clinical Trial Registry, Clinical trial number: ChiCTR2200061460.

Predicting conversion of ambulatory ACDF patients to inpatient: a machine learning approach

Background ContextMachine learning is a powerful tool that has become increasingly important in the orthopedic field. Recently, several studies have reported that predictive models could provide new insights into patient risk factors and outcomes. Anterior cervical discectomy and fusion (ACDF) is a common operation that is performed as an outpatient procedure. However, some patients are required to convert to inpatient status and prolonged hospitalization due to their condition. Appropriate patient selection and identification of risk factors for conversion could provide benefits to patients and the use of medical resources. PurposeThis study aimed to develop a machine-learning algorithm to identify risk factors associated with unplanned conversion from outpatient to inpatient status for ACDF patients. Study Design/SettingThis is a machine-learning-based analysis using retrospectively collected data. Patient SamplePatients who underwent one- or two-level ACDF in an ambulatory setting at a single specialized orthopedic hospital between February 2016 to December 2021. Outcome MeasuresLength of stay, conversion rates from ambulatory setting to inpatient. MethodsPatients were divided into two groups based on length of stay: (1) Ambulatory (discharge within 24 hours) or Extended Stay (greater than 24 hours but fewer than 48 hours), and (2) Inpatient (greater than 48 hours). Factors included in the model were based on literature review and clinical expertise. Patient demographics, comorbidities, and intraoperative factors, such as surgery duration and time, were included. We compared the performance of different machine learning algorithms: Logistic Regression, Random Forest (RF), Support Vector Machine (SVM), and Extreme Gradient Boosting (XGBoost). We split the patient data into a training and validation dataset using a 70/30 split. The different models were trained in the training dataset using cross-validation. The performance was then tested in the unseen validation set. This step is important to detect overfitting. The performance was evaluated using the area under the curve (AUC) of the receiver operating characteristics analysis (ROC) as the primary outcome. An AUC of 0.7 was considered fair, 0.8 good, and 0.9 excellent, according to established cut-offs. ResultsA total of 581 patients (59% female) were available for analysis. Of those, 140 (24.1%) were converted to inpatient status. The median age was 51 (IQR 44–59), and the median BMI was 28 kg/m2 (IQR 24–32). The XGBoost model showed the best performance with an AUC of 0.79. The most important features were the length of the operation, followed by sex (based on biological attributes), age, and operation start time. The logistic regression model and the SVM showed worse results, with an AUC of 0.71 each. ConclusionsThis study demonstrated a novel approach to predicting conversion to inpatient status in eligible patients for ambulatory surgery. The XGBoost model showed good predictive capabilities, superior to the older machine learning approaches. This model also revealed the importance of surgical duration time, BMI, and age as risk factors for patient conversion. A developing field of study is using machine learning in clinical decision-making. Our findings contribute to this field by demonstrating the feasibility and accuracy of such methods in predicting outcomes and identifying risk factors, although external and multi-center validation studies are needed.

Older Age, Male Sex, and Early Start Time Lengthen the Recovery Room Stay Following Total Joint Arthroplasty in an Ambulatory Surgical Center.

Total joint arthroplasty (TJA) performed in the ambulatory surgical center (ASC) has been shown to be safe and cost-effective for an expanding cohort of patients. As criteria for TJA in the ASC become less restrictive, data guiding the efficient use of ASC resources are crucial. We sought to identify factors associated with length of stay in the recovery room after primary total hip arthroplasty (THA) and total knee arthroplasty (TKA) performed in the ASC. We conducted a retrospective review of 411 patients who underwent primary THA or TKA at our institution's ASC between November 2020 and March 2022. We collected patient demographics, perioperative factors, success of same-day discharge (SDD), and length of time in the recovery room. Of 411 patients, 100% had successful SDD. The average length of time spent in recovery was 207 minutes (SD: 73.9 minutes). Predictors of longer time in recovery were increased age, male sex, and operative start time before 9:59 am. Body mass index, preoperative opioid use, Charlson Comorbidity Index, type of surgery (THA vs TKA), urinary retention risk, and type of anesthesia (spinal vs general) were not significant predictors of length of time in the recovery room. In this retrospective study, factors associated with increased length of time in the recovery room included older age, male sex, and operative start time before 9:59 am. Such factors may guide surgeons in determining the optimal order of cases for each day at the ASC, but further prospective studies should seek to confirm these observations.

Development of the Kinetic Equation of the Groove Corrosion Process for Predicting the Residual Life of Oil-Field Pipelines

One of the main reasons for oil-field pipeline failure is groove corrosion. The residual life of such pipelines is estimated based on defectoscopy corrosion rate—a ratio of the formed «groove» depth to the pipeline operation start time. In this case, it is supposed that, in the future, the «groove» will deepen at the same rate for the remaining period of the pipe’s operation. However, sometimes, oil-field pipeline operation experience shows that the remaining time of safe operation is much less than the calculated one. In this article, such a discrepancy is explained via the acceleration of the groove corrosion rate in the process of «groove» deepening due to the increasing level of mechanical stresses in the surrounding metal, which intensifies the corrosion process as a result of the mechanochemical effect. Based on a literature analysis and calculated data, the kinetic equation of the groove corrosion rate for an oil-field pipeline is proposed, which accounts for the acceleration of the process rate as the pipeline is operated and allows the more accurate estimation of its remaining service life.

235 Late Start Times Do Not Disproportionately Prolong Operating Times in Major Head and Neck Reconstruction

Abstract Introduction Operating start time delays are deemed as having a detrimental effect on theatre efficiency, subsequent delays, costs, and potentially outcomes. This study assessed the significance of delayed operating start times on major head and neck reconstruction cases and whether later starts led to disproportionately later finishes. Focus was placed on free osteocutaneous fibula flap reconstruction due to long operating times, difficult anaesthesia, frequently overrun and the perception of increased morning efficiency. Method Single centre identification of 26 patients using coding informatics that were diagnosed with an intra oral malignancy or osteoradionecrosis requiring reconstruction with a free osteocutaneous fibula flap. Data was manually retrieved between 2015 to 2020 from electronic patient records and statistical analysis was completed using Microsoft Excel. Results Total number of patients collated was 27, however 1 was excluded due to insufficient electronic logging of patient data. The total mean age was 64.8 (40-79), 50% were male (13) and 50% were female (13). The mean start time was 9:57, end time was 18:52 and duration was 10:50 (4:46 to 13:42). For surgery start times before 10:00 a.m. the mean start time was 9:31, end time was 20:16 and duration was 10:46 (8:30 to 22:56). For surgery start times after 10:00 a.m. the mean start time was 10:22, end time was 19:25 and duration was 10:54 (10:01 to 00:51). Conclusions Delayed operating start times have minimal significance on theatre efficiency and don’t disproportionally prolong operating times in major head and neck reconstruction cases.

928 The Golden Patient: A Concept to Improve Trauma Theatre Efficiency

Abstract Aim Golden patient (GP) is a pre-selected first patient on the next day’s trauma theatre list, with suitable medical fitness and a clear surgical plan. This study aimed to evaluate whether the GP concept improved the start times of theatre lists and the operating efficiency of the Aberdeen trauma unit. Method This prospective study compared theatre starting times before and following an intervention to improve consideration of the GP concept among both trauma and theatre staff. Data was collected from pre-planned trauma theatre lists on Bluespier software the evening before and the morning of the list. The comparative mean of operation start times between the groups was established and a two-sided t-test was performed to evaluate the significance between the groups. Results Post-interventional analysis identified 32 GPs out of which 28 persisted as first patients on the lists. The remaining 4 patients were deferred either due to an overnight emergency that took priority or a change in medical status that required them to be moved down the list. The mean operation start time was 10:00 compared to 10:14 pre-intervention. Further, in the re-audit, the mean operation start time was reduced by 39 minutes (p&amp;lt;0.01) when the GP remained first on the list. Conclusions The concept of GP has improved the theatre start times which is further evident in the delay to the start of the list when the GP is not employed. Additional contributing factors that influence theatre efficiency and require further review include anaesthetic planning, patient transport and others.

1237 Audit Project on Golden Patient Policy Adherence and Its Improvement to Theatre Efficiency

Abstract Aim The Golden Patient (GP) is the first patient listed for theatre next day identified and reviewed the day before, with the aim to improve theatre start times and overall efficiency. We aimed to compare the data before implementation of the GP against post-implementation at University Hospital North Durham (UHND) to assess if improvement in efficiency was achieved. We also aimed to analyse the appropriateness of patients listed as GP. Method We analysed data of 45 listed GPs between April and August 2022 as well as 50 patients listed first in theatre prior to GP implementation and compared the documented operation start times. We then compared the data of the listed GPs against local trust criteria for identifying the GP which includes ASA grade/ anaesthetic type, case duration, surgical team availability. Results When comparing pre- and post-implementation of the Golden Patient guidelines, surgical start times improved on average by 30 minutes. In the GPs, 62.9% met all criteria. Compliance was mostly affected by the number of patients not sent for before 0830 AM (only 68.6% of cases met this criterion.) Otherwise, 97.1% of cases met ASA/anaesthetic criteria, and 94.3% met case duration criteria. Conclusions We saw a significant improvement in the average starting times of theatres with implementation of the GP. We also found that we were good at identifying potential GPs however there was much room for improvement with logistics and actually getting patients to theatre quickly.

Preventive Priority Setting Against Multiple Controller Failures in Software Defined Networks

This paper proposes a preventive priority setting model to minimize the worst-case maximum utilization ratio against multiple controller failures in software defined networks. For a set of controllers able to manage a switch, we introduce a priority for each controller to become the main controller that controls the switch. Once the existing main controller fails, the survived controller which has the highest priority works as the main controller. This reassignment is automatically obtained according to the priority setting decided at the network operation start time. In this way, the proposed model provides a prompt recovery with reducing the network instability due to unnecessary controller reassignment. We formulate the proposed model in two different forms, which are an integer linear programming formulation and a min-max formulation. We prove that the considered problem is NP-hard. A basic heuristic is introduced based on the min-max formulation. Its two extensions are further developed considering the accuracy and the computation time in practical computation. Numerical results reveal that, compared to two baselines that sacrifice certain network stability to achieve a more flexible reassignment, the proposed model reduces the network instability by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$27\%$</tex-math></inline-formula> and <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$52\%$</tex-math></inline-formula> in average, respectively, with obtaining the comparable maximum utilization ratio.

Weight Is a Predictor of Delayed Operation Time in Primary Isolated Anterior Cruciate Ligament Reconstruction.

Few studies have evaluated the impact of obesity on operation time in patients with ACL reconstruction. The purpose of this study was to understand the effect of obesity on operation time in patients with arthroscopic anterior cruciate ligament (ACL) reconstruction. A total of 103 patients were included. The mean pure operation time was 45.9 ± 13.4 min. Considering that 15 min incremental increases in operation time are an independent risk factor for complications, all patients were classified into two groups according to operation time: more or less than 61 min. Demographic data were compared between both groups. Pure operation time was defined as operative time without suture time (pure operation time = suture start time - operation start time). Correlation analysis between demographic data and pure operation time was performed, and multiple linear regression analysis was used to identify the predictors of pure operation time. The pure operation time ≥61 min group (n = 34) had a 14.7 kg higher weight and 4.5 kg/m2 higher body mass index (BMI) than those with pure operation time < 61 min (n = 69). Weight (r = 0.635, p < 0.001) and BMI (r = 0.584, p < 0.001) were positively correlated with operation time. Multiple linear regression analysis showed that weight (β = 0.635, p < 0.001) was the only predictor of operation time. A weight of 74.25 kg was a cut-off value for a pure operation time of >61 min. The weight and BMI of the group with pure operation time of ≥61 min were 14.7 kg and 4.5 kg/m2 higher, respectively. The weight of patients with ACL tears was a factor affecting delay in the operation time. Patients weighing over 74.25 kg were more likely to delay ACL reconstruction.

Complications of endoscopic sinus surgery for chronic rhinosinusitis in a tertiary care teaching hospital in Saudi Arabia

To aimed to determine the incidence of complications of endoscopic sinus surgery (ESS) and to investigate the factors associated with the occurrence of complications.In this retrospective study, we reviewed the medical records of all patients who had undergone ESS at King Saud University Medical City (KSUMC) between January 2015 and March 2022. Patients who underwent ESS for complicated acute sinusitis, sinonasal malignancy, and cerebrospinal fluid leak repair, and those who underwent extended ESS for indications other than chronic rhinosinusitis were excluded. This study was approved by the KSUMC Institutional Review Board.We included 1395 patients, 3 of whom had major complications and 28 had minor complications, resulting in an overall major complication rate of 0.2% and a minor complication rate of 2%. The most common major complication was orbital hematoma, and the most common minor complication was synechia. Moreover, the duration of surgery and laterality increased the risk of complications, whereas the use of image guidance had no effect.The ESS is a safe procedure. The operative start time and laterality were associated with an increased risk of complications and warrant further investigation.