Is ‘starting on time’ useful (or useless) as a surrogate measure for ‘surgical theatre efficiency’?*

Predictors of anesthesia ready time: Analysis and benchmark data

Objective

Patients undergoing congenital cardiac surgery require induction of anesthesia. Our objective was to identify the median anesthesia ready time and the predictors of this time.

Methods

By using the Society of Thoracic Surgeons Congenital Heart Surgery Database, we identified patients who underwent cardiopulmonary bypass procedures from 2017 to 2021. Univariate and multivariable regression modeling to predict the anesthesia ready time was performed using mixed-effects linear regression.

Results

After exclusion of outliers, 44,418 cases were analyzed. The median anesthesia ready time was 51 minutes (interquartile range, 38-66). On multivariable analysis, independent predictors of a longer anesthesia ready time included decreasing weight (0.3 min/10 kg, 95% CI, 0.1-0.6; P = .011), prematurity (1.5 minutes, 95% CI, 0.8-2.2; P < .001), and presence of chromosomal abnormality (3.4 minutes, 95% CI, 1.5-5.2; P < .001). An increase in the duration in anesthesia ready time was seen with increasing Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery mortality category with an additional 7.8 minutes (95% CI, 5.2-10.4; P < .001) for a Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery 5 procedure compared with Society of Thoracic Surgeons-European Association for Cardiothoracic Surgery 1. Emergency versus elective case designation was associated with an anesthesia ready time reduction of 3.6 minutes (95% CI, 1.1-6.1; P = .005), and an afternoon case start was associated with an anesthesia ready time reduction of 4.2 minutes (95% CI, 2.8-5.6; P < .001). The presence of an anesthesia trainee increased the anesthesia ready time by 3.8 minutes (95% CI, 2.6-5.0; P < .001). The presence of an airway in situ decreased the anesthesia ready time by 3.6 minutes (95% CI, 1.6-5.5; P < .001), whereas an in situ arterial line decreased the anesthesia ready time by 7.4 minutes (95% CI, 4.6-10.2; P < .001). Placement of a central venous line increased the anesthesia ready time by 8.5 minutes (95% CI, 5.9-11.1; P < .001).

Conclusions

The median anesthesia ready time was 51 minutes. For patients with characteristics associated with prolonged anesthesia ready time, consideration should be given to allocation of additional anesthesia staffing to improve efficiency.

Getting operating theatre metrics right to underpin quality improvement: understanding limitations of NHS Model Hospital calculations

The Model Hospital is an NHS online resource summarising performance data for, amongst other things, operating theatres categorised by NHS Trust and specialty. As an official source of information, it might be assumed that metrics, such as 'average late start time', 'average early finish time', and 'average late finish time', are calculated in a way to reflect performance in these domains, but this is not the case. These values are, respectively, only for those lists that start late, finish early, and finish late, with the number of lists in each category unreported. The Model Hospital reports utilisation appropriately as 'touch time' (the time delivering anaesthesia and surgery) but prefers a 'capped' measure, in which any touch time occurring in late finishes is ignored. The Model Hospital aggregates utilisations across lists in a mathematically invalid way, which leads to the assumption that small aliquots of unused time on lists can be combined to create larger time blocks, in which to complete more operations. We present alternative, more intuitive, and mathematically conventional methods to derive performance metrics using the same data. The results have implications for hospitals developing their own dashboards and international organisations seeking to create national databases for operating theatre performance.

The Golden Patient Initiative: A Systematic Review

Operating theatres and surgical resource consumption comprise a significant proportion of healthcare costs. Inefficiencies in theatre lists remain an important focus for cost management, along with reducing patient morbidity and mortality. With the emergence of the coronavirus disease 2019 (COVID-19) pandemic, the number of patients on theatre waiting lists has surged. Hence, there is a pressing need to utilise the already limited theatre time and fraught resources with innovative methods. In this systematic review, we discuss the Golden Patient Initiative (GPI), in which the first patient on the operating list is pre-assessed the day prior to surgery, and we aim to assess its impact and overall efficacy. A literature search using the following four databases was conducted to identify and select all clinical research concerning the GPI: Medical Literature Analysis and Retrieval System Online (MEDLINE), Cumulative Index to Nursing and Allied Health Literature (CINAHL), Excerpta Medica Database (EMBASE), and the Cochrane library. Two independent authors screened articles against the eligibility criteria, using a process adapted from the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Data extracted included outcomes measured, follow-up period, and study design. The results showed significant heterogeneity, and hence a narrative review was conducted; 13 of the 73 eligible articles were included for analysis. Outcomes included delay in theatre start time, number of surgical case cancellations, and changes to total case numbers. Across the studies, a 19-30-minute improvement in theatre start time was reported (p<0.05), as well as a statistically significant decrease in case cancellations. Our analysis provides encouraging conclusions with regard to greater theatre efficiency following the application of GPI, a low-cost solution that can easily be implemented to help improve patient safety and lead to cost savings. However, at present, it is largely implemented among local trusts, and hence larger multi-centre studies are required to gather conclusive evidence about the efficacy of the initiative.

Case-Mix Moderation of the Relationship Between OR Performance Metrics and Utilization

We investigated the impact of the case-mix ratio of inpatients to outpatients on the relationships between OR utilization and late starts, turnover time, delays, cancellations, and idle time at an academic medical center in the southeastern United States. After extracting 55 months of data from the surgical repository, we used simple and multiple linear regression models to analyze the data and determine the strength and direction of the relationships among the variables. We compared models comprising proportionally more inpatients to models comprising proportionally more outpatients for each metric to ascertain the effects of case mix on OR utilization. Idle time had the greatest effect on OR utilization, followed by late starts and turnover time. Case mix moderated the relationship between OR utilization and the metrics of cancellations and turnover time. Perioperative leaders may enhance OR utilization by monitoring and addressing idle time and late starts and scheduling an appropriate mix of inpatients and outpatients.

The effect of overlapping surgical scheduling on operating theatre productivity: a narrative review

This article reviews the background to overlapping surgery, in which a single senior surgeon operates across two parallel operating theatres; anaesthesia is induced and surgery commenced by junior surgeons in the second operating theatre while the lead surgeon completes the operation in the first. We assess whether there is any theoretical basis to expect increased productivity in terms of number of operations completed. A review of observational studies found that while there is a perception of increased surgical output for one surgeon, there is no evidence of increased productivity compared with two surgeons working in parallel. There is potential for overlapping surgery to have some positive impact in situations where turnover times between cases are long, operations are short (<2 h) and where 'critical portions' of surgery constitute about half of the total operation time. However, any advantages must be balanced against safety, ethical and training concerns.

Getting going on time: reducing neurophysiology set-up times in order to contribute to improving surgery start and finish times

At the Walton Centre we conduct a relatively large number of complex and lengthy elective (booked) spinal operations. Recently, we have had a particular problem with half or more of these sessions finishing late, resulting in staff discontent and greater use of on-call staff.

These operations require patient monitoring by neurophysiology clinical scientists. Before the surgeon can start the operation, in-theatre neurophysiological measurements are required to establish a baseline. We reasoned that reducing this set-up time would reduce the risk of surgery starting late, and so the whole session finishing later than expected.

In this project we redesigned the neurophysiology parts of in-theatre patient preparation. We conducted five Plan-Do-Study-Act cycles over 3 months, reducing the duration of pre-surgery preparation from a mean of 70 min to around 50 min. We saw improvements in surgical start times and session finish times (both earlier by roughly comparable amounts). The ultimately impact is that we saw on-time session finishes improve from around 50% to 100%. Following this project, we have managed to sustain the changes and the improved performance.

The most impactful change was to conduct in-theatre neurophysiology patient preparation simultaneously with anaesthesia, rather than waiting for this to finish; when we performed this with a pair of clinical scientists, we were able to complete neurophysiology patient preparation by the time the anaesthetist was finished, therefore not introducing delays to the start of surgery. A final change was to remove a superfluous preparatory patient-baseline measurement.

This is a very challenging and complex environment, with powerful stakeholders and many factors and unpredictable events affecting sessions. Nevertheless, we have shown that we can make improvements within our span of influence that improve the wider process. While using pairs of staff requires greater resource, we found the benefit to be worthwhile.

A graphical assessment of emergency surgical list efficiency to determine operating theatre capacity needs

BACKGROUND

Unlike elective lists, full utilisation of an emergency list is undesirable, as it could prevent patient access. Conversely, a perpetually empty emergency theatre is resource wasteful. Separately, measuring delayed access to emergency surgery from time of booking the urgent case is relevant, and could reflect either deficiencies in patient preparation or be because of an occupied (over-utilised) emergency theatre.

METHODS

We developed a graphical method recognising these two separate but linked elements of performance: (i) delayed access to surgery and (ii) operating theatre utilisation. In a plot of one against the other, data fell into one of four quadrants, with delays associated with high utilisation signifying the need for more emergency capacity. However, delays associated with low utilisation reflect process deficiencies in the emergency patient pathway. We applied this analysis to 73 consecutive lists (>300 cases) from two UK hospitals.

RESULTS

Although both hospitals experienced similar rates of delayed surgery (21.8% vs 21.0%; P=0.872), in one hospital 83% of these were associated with low emergency theatre utilisation (suggesting predominant process deficiencies), whereas in the other 73% were associated with high utilisation (suggesting capacity deficiency; P<0.0001). Increasing emergency capacity in the latter resulted in shorter delays (just 6.7% cases excessively delayed; P<0.0001 for effect of intervention).

CONCLUSIONS

This simple graphical analysis indicates whether more emergency capacity is necessary. We discuss potential applications in managing emergency surgery theatres.

Efficiency Metrics at an Academic Freestanding Ambulatory Surgery Center: Analysis of the Impact on Scheduled End-Times

BACKGROUND

Understanding the impact of key metrics on operating room (OR) efficiency is important to optimize utilization and reduce costs, particularly in freestanding ambulatory surgery centers. The aim of this study was to assess the association between commonly used efficiency metrics and scheduled end-time accuracy.

METHODS

Data from patients who underwent surgery from May 2018 to June 2019 at an academic freestanding ambulatory surgery center was extracted from the medical record. Unique operating room days (ORDs) were analyzed to determine (1) duration of first case delays, (2) turnover times (TOT), and (3) scheduled case duration accuracies. Spearman's correlation coefficients and mixed-effects multivariable linear regression were used to assess the association of each metric with scheduled end-time accuracy.

RESULTS

There were 1378 cases performed over 300 unique ORDs. There were 86 (28.7%) ORDs with a first case delay, mean (standard deviation [SD]) 11.2 minutes (15.1 minutes), range of 2-101 minutes; the overall mean (SD) TOT was 28.1 minutes (19.9 minutes), range of 6-83 minutes; there were 640 (46.4%) TOT >20 minutes; the overall mean (SD) case duration accuracy was -6.6 minutes (30.3 minutes), range of -114 to 176; and there were 389 (28.2%) case duration accuracies ≥30 minutes. The mean (SD) scheduled end-time accuracy was 6.9 minutes (68.3 minutes), range of -173 to 229 minutes; 48 (15.9%) ORDs ended ≥1 hour before scheduled end-time and 56 (18.6%) ORDs ended ≥1 hour after scheduled end-time. The total case duration accuracy was strongly correlated with the scheduled end-time accuracy (r = 0.87, 95% confidence interval [CI], 0.84-0.89, P < .0001), while the total first case delay minutes (r = 0.12, 95% CI, 0.01-0.21, P = .04) and total turnover time (r = -0.16, 95% CI, 0.21-0.05, P = .005) were less relevant. Case duration accuracy had the highest association with the dependent variable (0.95 minutes changed in the difference between actual and schedule end time per minute increase in case duration accuracy, 95% CI, 0.90-0.99, P < .0001), compared to turnover time (estimate = 0.87, 95% CI, 0.75-0.99, P < .0001) and first case delay time (estimate = 0.83, 95% CI, 0.56-1.11, P < .0001).

CONCLUSIONS

Standard efficiency metrics are similarly associated with scheduled end-time accuracy, and addressing problems in each is requisite to having an efficient ambulatory surgery center. Pursuing methods to narrow the gap between scheduled and actual case duration may result in a more productive enterprise.

Delay of Surgery Start Time: Experience in a Nigerian Teaching Hospital

Background:

Operating room delay has multiple negative effects on the patients, surgical team, and the hospital system. Maximum utilization of the operating room requires on-time knife on the skin and efficient turnover. Knowledge of the reasons for the delay will form a basis toward proffering solutions.

Patients and Methods:

This was a prospective study of all consecutive elective cases done over a 15-month period from January 2016 to March 2017. Using our departmental protocol that “knife on skin” for the first elective case should be 8.00am, the delay was defined as a surgery starting later than 8.00am for the first cases while the interval between the cases of >30 min for the knife on the skin was used for subsequent cases. Reasons for delay in all cases of delay were documented. The prevalence and causes of the delays were analyzed. P < 0.05 was considered statistically significant.

Results:

Of 1178 surgeries performed during the period of study, 1170 (99.3%) of cases were delayed. The mean delay time was 151 min for all cases. First on the list had a longer delay time than others; 198.9 min versus 108.5 min (P = 0.000). Delay in the first cases accounted for 47.5% of all delayed cases. Overall, patient-related factor was the most common cause of delay (31.3%) followed in descending order by surgeon-related factor (28.5%) and hospital-related factor (26.2%). Patient-related factors accounted for 43.2% of first-case delays.

Conclusion:

Delays encountered in this study were multifactorial and are preventable. Efforts should be directed at these different causes of delay in the theater to mitigate these delays and improve productivity.

Determinants of lost theatre capacity

Secondary care Trusts nationwide are continuing to fail the 18-week referral to treatment (RTT) target despite several initiatives to improve theatre efficiency (2018 NHS England review). A limitation of wasted theatre productivity is required to alleviate pressures on waiting lists. Productivity, which is a measure of treatment time as a proportion of available/allocated time, takes into consideration variations in operator performance, early (non-funded) theatre starts, and over-run, and its analysis enables the determination of theatre downtime and lost theatre capacity. We monitored productivity over a 12-week period and performed downtime analysis as reported in the NHS Improvement national audit (NHSI). Results showed a marked but predictable variation in productivity connected to turnaround and session list scheduling. Productivity and booking efficiency correlated uniformly (Pearson's r=0.82). Theatre downtime was analysed with respect to three components defined in the NHSI national audit: late starts, early finish, and turnaround. We found that lost theatre time was predominantly due to early finishes; late starts were infrequent. Transport time correlated unfavourably with productivity (Pearson's r=-0.29, p=0.037) and over-run (r=0.44), and prolonged transport times were shorter when surgery was performed in a dedicated day surgery unit. Calculating the mean transport times for lists with high compared with low productivity helped us set a benchmark for patient transport times for future audit.

Rational performance metrics for operating theatres, principles of efficiency, and how to achieve it

BACKGROUND

Several performance metrics are commonly used by National Health Service (NHS) organizations to measure the efficiency and productivity of operating lists. These include: start time, utilization, cancellations, number of operations and gap time between operations. The authors describe reasons why these metrics are flawed, and use clinical evidence and mathematics to define a rational, balanced efficiency metric.

METHODS

A narrative review of literature on the efficiency and productivity of elective NHS operating lists was undertaken. The aim was to rationalize how best to define and measure the efficiency of an operating list, and describe strategies to achieve it.

RESULTS

There is now a wealth of literature on how optimally to measure the performance of elective surgical lists. Efficiency may be defined as the completion of all scheduled operations within the allocated time with no over- or under-runs.

CONCLUSION

Achieving efficiency requires appropriate scheduling using specific procedure mean (or median) times and their associated variance (standard deviation or interquartile range) to calculate the probability they can be completed on time. The case mix may be adjusted to yield better time management. This review outlines common misconceptions applied to managing scheduled operating theatre lists and the challenges of measuring unscheduled operations in emergency settings.

Rational planning of operating lists: a prospective comparison of 'booking to the mean' vs. 'probabilistic case scheduling' in urology

The efficient use of operating theatres requires accurate case scheduling. One common method is 'booking to the mean'. Here, the mean times for individual operations are summed to approximate the time allocated to the list. An alternative approach is 'probabilistic scheduling'. Here, the means and standard deviation of the individual case times are combined to estimate the probability that the planned list will finish on time. This study assessed how probabilistic booking would have changed list utilisation, over-running and case cancellations in 60 urology lists during eight months that had been 'booked to the mean'. Booking to the mean resulted in 53/60 (88%) lists over-running and correctly predicted the finish times in just 13% of lists. Out of 264 patients, 36 (14%) were cancelled on the day due to over-runs in 24/60 (40%) lists. In contrast, probabilistic scheduling correctly predicted an over-run or under-run in 77% of lists, which would have allowed the case mix to be adjusted to prevent cancellation and optimise utilisation.

Changing operating lists on the day of surgery: a service evaluation

This study aims to explore how often the operating list is changed on the day of surgery and the reasons why this may occur. The purpose was to analyse the wider potential impact that changing the list on the day of surgery may have on patient safety, patient satisfaction and theatre efficiency. Survey data was collected across a multi-specialty elective operating department. The findings demonstrated that a significant change in operating lists occurred in 37.3% of sessions, for a variety of potentially avoidable reasons. We concluded that improved organisation and communication before the planned session could reduce the occurrence of changes, thereby increasing patient safety, theatre efficiency and potentially reducing incidents.

"Knife to skin" time is a poor marker of operating room utilization and efficiency in cardiac surgery

BACKGROUND

Markers of operation room (OR) efficiency in cardiac surgery are focused on "knife to skin" and "start time tardiness." These do not evaluate the middle and later parts of the cardiac surgical pathway. The purpose of this analysis was to evaluate knife to skin time as an efficiency marker in cardiac surgery.

METHODS

We looked at knife to skin time, procedure time, and transfer times in the cardiac operational pathway for their correlation with predefined indices of operational efficiency (Index of Operation Efficiency - InOE, Surgical Index of Operational Efficiency - sInOE). A regression analysis was performed to test the goodness of fit of the regression curves estimated for InOE relative to the times on the operational pathway.

RESULTS

The mean knife to skin time was 90.6 ± 13 minutes (23% of total OR time). The mean procedure time was 282 ± 123 minutes (71% of total OR time). Utilization efficiencies were highest for aortic valve replacement and coronary artery bypass grafting and least for complex aortic procedures. There were no significant procedure-specific or team-specific differences for standard procedures. Procedure times correlated the strongest with InOE (r = -0.98, p < 0.01). Compared to procedure times, knife to skin is not as strong an indicator of efficiency. A statistically significant linear dependence on InOE was observed with "procedure times" only.

CONCLUSIONS

Procedure times are a better marker of OR efficiency than knife to skin in cardiac cases. Strategies to increase OR utilization and efficiency should address procedure times in addition to knife to skin times.

[Management for the operating room]

Business companies, which in the current times also includes hospitals, must create customer benefits and as a prerequisite for this must sustainably generate profits. Management in the world of business means the formation and directing of a company or parts of a company on a permanent basis, whereby management in this context is not exercising power but function. This concept of management is exemplary developed in this article for the important services sector of the operating room (OR) and individual functions, such as resource control, capacity planning and materials administration are presented in detail. Some OR-specific management challenges are worked out. From this it becomes clear that the economic logic of the most efficient implementation possible is not a contradiction of medical ethics, enabling the most effective treatment possible for patients while safeguarding the highest possible levels of safety and quality. The article aims to build a bridge for medical specialists to the language and world of commerce, emphasizing the profession-based competence and hopefully to arouse interest to go into more detail.

Enhancement opportunities in operating room utilization; with a statistical appendix

BACKGROUND

The purpose of this study was to assess the direct and indirect relationships between first-case tardiness (or "late start"), turnover time, underused operating room (OR) time, and raw utilization, as well as to determine which indicator had the most negative impact on OR utilization to identify improvement potential. Furthermore, we studied the indirect relationships of the three indicators of "nonoperative" time on OR utilization, to recognize possible "trickle down" effects during the day.

MATERIALS AND METHODS

(Multiple) linear regression analysis and mediation effect analysis were applied to a data set from all eight University Medical Centers in the Netherlands. This data set consisted of 190,071 OR days (on which 623,871 surgical cases were performed).

RESULTS

Underused OR time at the end of the day had the strongest influence on raw utilization, followed by late start and turnover time. The relationships between the three "nonoperative" time indicators were negligible. The impact of the partial indirect effects of "nonoperative" time indicators on raw utilization were statistically significant, but relatively small. The "trickle down" effect that late start can cause resulting in an increased delay as the day progresses, was not supported by our results.

CONCLUSIONS

The study findings clearly suggest that OR utilization can be improved by focusing on the reduction of underused OR time at the end of the day. Improving the prediction of total procedure time, improving OR scheduling by, for example, altering the sequencing of operations, changing patient cancellation policies, and flexible staffing of ORs adjusted to patient needs, are means to reduce "nonoperative" time.

An audit of operating room time utilization in a teaching hospital: is there a place for improvement?

Aim. To perform a thorough and step-by-step assessment of operating room (OR) time utilization, with a view to assess the efficacy of our practice and to identify areas of further improvement. Materials and Methods. We retrospectively analyzed the most ordinary general surgery procedures, in terms of five intervals of OR time utilization: anaesthesia induction, surgery preparation, duration of operation, recovery from anaesthesia, and transfer to postanaesthesia care unit (PACU) or intensive care unit (ICU). According to their surgical impact, the procedures were defined as minor, moderate, and major. Results. A total of 548 operations were analyzed. The mean (SD) time in minutes for anaesthesia induction was 19 (9), for surgery preparation 13 (8), for surgery 115 (64), for recovery from anaesthesia 12 (8), and for transfer to PACU/ICU 12 (9). The time spent in each step presented an ascending escalation pattern proportional to the surgical impact (P = 0.000), which was less pronounced in the transfer to PACU/ICU (P = 0.006). Conclusions. Albeit, our study was conducted in a teaching hospital, the recorded time estimates ranged within acceptable limits. Efficient OR time usage and outliers elimination could be accomplished by a better organized transfer personnel service, greater availability of anaesthesia providers, and interdisciplinary collaboration.

A predetermined first patient on the trauma list can improve theatre start times

INTRODUCTION

The concept of the golden patient (GP) was introduced to our busy teaching hospital, in April 2009, with the aim of improving our trauma theatre start times. The GP is a pre-selected first patient on the following day trauma list who is medically fit with a clear surgical plan.

METHODS

This prospective study compared the trauma theatre start times over a two month period following the introduction of the GP, with a similar two month period prior to the introduction of the GP. A two-sided t-test was used to evaluate statistical significance between groups.

RESULTS

Of the 55 planned trauma lists analysed, 42 had a designated GP on it (76%), 37 of which remained first on the actual trauma list (88%). The mean operation start time for the pre-GP lists was 10:03 compared to 09:33 for the actual GP lists (P<0.001). The reception, anaesthetic and operation start times for pre-GP lists compared with lists where no GP was selected were not statistically significant suggesting that the GP was the cause of the significance.

CONCLUSION

The introduction of the GP to our trauma lists has made a significant improvement to theatre start times and consequently surgical theatre efficiency.

Has the introduction of an admissions lounge affected theatre start times in a busy teaching hospital environment?

The Admissions Lounge (AL) was introduced with the aims of reducing the number of late starts, improving the patient experience and reducing preoperative length of stay to save bed days. To determine whether a reduction in number of late starts was achieved, 237 start times from pre and post introduction of the AL were collected and analysed. There was no statistically significant difference (p > 0.05) between the percentage of lists delayed or the mean delay between pre and post introduction of the AL (mean delay for post AL was 10.17 minutes compared to 9.85 minutes pre AL). The AL had no impact on theatre start times, neither improving nor reducing the operating theatre efficiency in this respect.