An analysis of time utilization and cancellations of scheduled cases in the main operation theater complex of a tertiary care teaching institute of North India.

CONTEXT: Operation theater (OT) utilization. AIMS: To analyze the time utilization and to assess the stated causes of cancellations of scheduled cases in the OT complex of a tertiary care teaching institute. SETTINGS AND
DESIGN: This prospective study was carried out from December 2010 to April 2011.
MATERIALS AND METHODS: each of the 16 OT tables was observed for 6 days (total 96 days). The available resource hours were taken as 0800-1600 hrs. (480 min/day; 46,080 min in 96 days). The following parameters were recorded--time spent on supportive services, time spent on actual surgery, room turn over time, time spent for total procedure and time between entry and exit of patient. STATISTICAL ANALYSIS: Data were analyzed using the SPSS software version 15.
RESULTS: Of the total 325 scheduled cases, 252 were operated and 73 (22.5%) were cancelled. There were delays on 15 days (15.63%) in starting the OT table at the scheduled time. Of the total resource hours (46,080 min), the mean "Raw utilization" was 37,573 min (81.54%) and the "Adjusted utilization" was 39,668 min (86.09%). The mean time spent on "supportive services" was 5539 min (12.02%) and on "actual surgery"' was 28,277 min (61.37%), and the "room turn over time" was 2095 min (5.39%). Among the stated reasons for cancellations, lack of operating time--57 cases (78.1%)--was the most common.
CONCLUSION: Study of time utilization and cancellation are important tools in assessing the optimal utilization of available resource hours in an OT.

Introduction

The operation theater (OT) in a hospital is a very important facility. As the major part of the hospital budget is spent on OTs, they have to be utilized maximally to ensure optimum resource utilization.[1] For optimum cost-benefit, scientific and efficient management of an OT is essential. Hospitals in developing countries absorb more resources than any other kind of recurrent government spending on health.[2] Although the actual percentage varies from country to country, on an average, 50-80% of the public health sector resources in money and trained personnel is used in hospitals.[2]

One measure to assess how well an OT functions is the “time utilization”. This was defined by Donham and colleagues as the quotient of hours of OT time actually used during elective resource hours and the actual number of elective resource hours available for use.[3]

Planning of various activities in an OT must be done systematically so that the allocation of staff is done efficiently. This will involve close cooperation amongst surgeons and anesthetists. Realistic scheduling of procedures will avoid cancellation of operations. Potentially long operations should be identified and planned in a way that it is possible to complete them within the time available.

Cancellations interrupt patient flow and decrease the throughput of the theaters, resulting in wasted resources. Cancellation also results in psychological trauma to patients as they have to undergo the pre-operative mental and clinical preparation again. The emotional and economic implications for the patient and their families can be significant.[4]

There are various factors contributing to effective utilization of available resource hours, such as trained staff, appropriate facilities, equipment, good communication, operational layout, etc. Good utilization also depends on a complex interaction between the availability of personnel and resources and on the attitudes and good practice of all staff involved. Efficiency in the theater is inevitably influenced by a huge range of surrounding resources such as pre-operative planning and assessment, beds, theater sterile supply unit (TSSU) capacity and staffing levels in other disciplines.

The present study was conducted to analyze the time utilization and cancellations of scheduled cases in the main OT complex of an apex tertiary care hospital and teaching institute.

Materials and Methods

Ethics

Prior approval to carry out the study was obtained from the Ethics Committee of the institute and confidentiality was maintained throughout the audit.

Study site

The main OT complex consists of 16 functional OT tables that are situated on the fourth and fifth floors of the hospital [Table 1].

Table 1

Specialty-wise distribution of OT tables on the fourth and fifth floors of the hospital

Name of specialty	Total number of OT tables
General Surgery	3
Urology	2
Orthopedics	2
Plastic Surgery	2
E.N.T.	2
Neurosurgery	3
Gynecology	2

OT – Operation theater

Sampling technique, selection criteria and data collection

This prospective study was carried out between December 2010 and April 2011. The observations were made only for scheduled cases. This list was generated before 2000 hrs on the previous day. The main OT timing for the scheduled elective cases was from 0800-1600 hrs. The last case taken up under anesthesia was induced before 1400 hrs. The cases that were induced after 1400hrs and emergency surgeries were excluded. As it was a single-worker study, one OT table was observed for a period of 6 days but not on consecutive days; therefore, a total of 96 days of observations for the 16 OT tables were made during the study period. The observations were not made on Saturdays, Sundays and gazetted holidays. The selection of OT table was performed on a random basis.

Observations made

The following times were recorded for each scheduled case for that day on that table.

Table start time: The time at which the patient entered the OT.

Surgery start time: The time at which skin preparation started.

Surgery end time: The time at which dressing was applied.

Table finish time: The time at which the patient was shifted out of the OT.

These times were pre-defined after consultation with surgeons and anesthesiologists from the institute. The observations were recorded on the self-developed performas. The following times were then derived and recorded in minutes [Figure 1]:

Figure 1

Flow chart depicting the operative process

Time spent on supportive services: It was the time between the patient going inside the OT and the start of surgery. The activities performed during this time were anesthetizing the patient and arrangement of sterile trolleys.

Time spent on actual surgery: It was the time between start of surgery till the end of surgery, i.e. the time between skin preparation to application of dressing. This is the time during which the surgery was performed.

Room turn over time: It was the time between one patient leaving the OT and the next patient entering it. The activities performed during this time were room cleaning, removal of soiled linen, sponges, disposal of tissues removed during operation, carbolization of the OT table and making the OT table ready with the clean linen. This room turnover time was applicable only when a second case was scheduled and operated to immediately follow the first case on a particular OT table.

Total time for the procedure: It was the time from the start of room setup to the end of room cleanup. It includes time spent on supportive services, actual surgery time, anesthesia reversal time and room turn over time. This time was used to calculate the adjusted utilization.

Time between entry and exit of patient: This was calculated as the duration between table start time and table finish time. This time was used to calculate the raw utilization.

Data analysis

Raw utilization was taken as the ratio of the time that patients were in the OT (min) to the available resource time (min).[5] It is the total hours of elective cases performed within the OT time divided by the hours of allocated block time. It was calculated in percent (%) as:[6]

Total hours of cases performed ÷ total hours of OT time allocated × 100

The percentage of resource hours spent on a particular activity was calculated as:

The room turnover time was applicable only when a second case was scheduled and operated to immediately follow the first case on a particular OT table. Hence, “n” (i.e., number of days) for calculating mean time and percentage mean time was 81 days instead of 96 days. The comparison of time utilized on different OT tables was performed using the one-way ANOVA.

Results

Overall results

A total of 325 cases were scheduled during the study period, of which 252 cases were operated and 73 (22.46%) cases were cancelled due to various reasons. The OT table-wise percentage mean time per day spent on different parameters is given in Table 2. The room turnover time for each OT table is given in Table 3.

Table 2

OT table wise percentage mean time per day spent on different parameters

OT Table No.	Number of Days (n)	Raw utilization in minutes (mean/day ± SD)	Time spent on supportive services in minutes (mean/day ± SD)	Time spent on actual surgery in minutes (mean/day ± SD)	Total time for the procedure in minutes (mean/day ± SD)
1	6	373.67 (77.84±11.53)	52.33 (10.90±3.53)	249.33 (51.94±21.95)	398.33 (82.99±11.31)
2	6	347.67 (72.43±20.32)	49.83 (10.38±3.60)	269 (56.04±18.19)	364.83 (76.01±19.43)
3	6	388 (80.83±10.23)	57.83 (12.05±2.89)	283.17 (58.99±11.37)	403.33 (84.03±10.90)
4	6	394.5 (82.19±5.17)	67 (13.96±2.87)	287.17 (59.83±5.77)	420.33 (87.57±5.01)
5	6	400.67 (83.47±7.73)	74.33 (15.49±7.32)	290 (60.42±15.25)	432.17 (90.04±5.71)
6	6	379.5 (79.06±24.59)	54.83 (11.42±7.29)	286.83 (59.76±23.61)	391.67 (81.60±23.76)
7	6	407.5 (84.90±7.36)	60 (12.5±6.00)	317.5 (66.15±10.37)	428.33 (89.24±7.30)
8	6	411.67 (85.76±14.29)	46.17 (9.62±3.82)	332.17 (69.20±15.34)	428.33 (89.24±11.54)
9	6	424.5 (88.44±8.34)	43.67 (9.1±2.71)	353.33 (73.61±8.20)	450 (93.75±5.71)
10	6	412.83 (86.01±5.75)	56.33 (11.74±4.15)	297.33 (61.94±5.14)	439.17(91.49±6.89)
11	6	355.5 (74.06±9.32)	51.33 (10.69±2.64)	263.33 (54.86±8.39)	390.83 (81.42±9.37)
12	6	448.67 (93.47±8.14)	77.83 (16.22±4.10)	338.83 (69.55±7.82)	464.5 (96.77±7.28)
13	6	414.33 (86.32±10.85)	67.67 (14.1±5.98)	318 (66.25±15.69)	432.83 (90.17±9.00)
14	6	412.5 (85.94±10.20)	61.67 (12.85±6.99)	316.67 (65.97±16.27)	423.33(88.20±10.47)
15	6	3.5.33 (63.61±20.95)	53.33 (11.11±3.07)	215 (44.79±20.62)	330 (68.75±18.80)
16	6	385.33 (80.28±16.93)	49 (10.21±2.99)	300.17 (62.53±16.82)	413.33 (86.11±18.50)
Over all	96	391.39 (81.54±14.00)	57.70 (12.02±4.74)	294.55 (61.37±15.40)	413.21 (86.09±13.38)

OT – Operation theater

Table 3

OT table-wise percentage mean room turnover time per day

OT table no.	Number of days (n)	Room turnover time in minutes (mean/day ± SD)
1	6	24.67 (5.14±4.28)
2	4	25.75 (5.36±3.30)
3	6	15.33 (3.20±1.04)
4	6	25.83 (5.37±2.95)
5	6	31.5 (6.5± 3.71)
6	3	24.33 (5.5±1.95)
7	5	25 (5.21±3.53)
8	4	25 (5.21±3.40)
9	6	25.5 (5.31±3.77)
10	6	26.33 (5.49±1.60)
11	6	35.33 (7.36±2.10)
12	5	19 (3.96±0.79)
13	4	27.75 (5.78±4.80)
14	3	21.67 (4.51±3.18)
15	5	29.6 (6.17±4.28)
16	6	28 (5.83±1.86)
Overall	81	25.86 (5.39±2.96)

OT – Operation theater

Variation in time

The reason for variation in time spent on supportive services included for example time spent in positioning of patient for surgery or catheterization. Other reasons included the patient's medical condition for example an increase or decrease in blood pressure on the table requiring time for stabilization. The variation in time spent on actual surgery was because of case mix. The case duration of surgeries conducted by various surgical specialties is different. In fact in the same specialty, each procedure requires different length of time. The time spent on supportive services, time spent on actual surgery, time between entry and exit of patient (raw utilization) and total time for the procedure (adjusted utilization) was significantly different among the 16 OT tables (P < 0.001), whereas the room turnover time was not significantly different among the various OT tables (P = 0.195).

Delays in start

There were delays on 15 days in starting the OT table at the scheduled time (8.00 am) during the study period [Tables 4 and 5]. These included late shifting of second patient on the list if the first patient was cancelled due to any reason, late shifting of first patient due to lack of a hospital attendant, late reporting by outdoor/day surgery patients, non availability of sterile equipment which was used up the previous day for an emergency. On one occasion, an emergency case was operated in the night until morning, which resulted in a delay. On another occasion, the patient needed nebulization before he was shifted to the OT table, which delayed the starting of the operation table.

Table 4

Delays in starting of OT on time in the morning

OT table no.	Number of delays
1	1
2	1
3	0
4	0
5	0
6	0
7	0
8	2
9	2
10	0
11	3
12	0
13	2
14	1
15	2
16	1
Total	15

OT – Operation theater

Table 5

Reasons and the number of delays in starting the operation table in the morning

Reason for delay	Number of delays	%
Patient shifted late from the ward	7	46.66
Patient reported late	4	26.67
Administrative cause-instruments not ready; OT light not functioning properly etc.	2	13.33
Emergency case was operated in the night so OT started late in the morning	1	6.67
Critical condition of the patient	1	6.67
Total	15	100

Cancellations

During the study period of 96 days, a total of 325 elective surgeries were scheduled on the 16 OT tables under observation. Seventy-three (22.5%) surgeries were cancelled [Table 6] due to various reasons [Table 7]. The highest number of cancellations were on OT table no. 2 (9/22 = 40.99%) and lowest on OT table no. 16 (0%). Cancellations due to lack of time (n = 57; 78.1%) resulted from improper scheduling leading to no time left to provide anesthesia. Cancellation due to unfavorable medical condition of the patient was responsible for 8.2% of the cancellations. A total of 4.1% of the patients on an outdoor basis did not report on the day of surgery, 4.1% of the patients were advised some work-up before the day of operation, which was not completed till the day of surgery, resulting in cancellation. In another 4.1%, the outdoor patients reported in a non-fasting state due to inadequate counseling. In the remaining 1.4% patients, the reason for cancellation was that the case was scheduled after the generation of the list leading to no pre anesthesia work up and thus lack of readiness for surgery.

Table 6

Cancellations on various OT tables

OT table no.	Surgeries done	Cancelled surgeries	Total scheduled cases	Cancellation (%)
1	20	6	26	23
2	13	9	22	40.09
3	13	3	16	18.75
4	19	3	22	13.63
5	19	5	24	20.83
6	13	7	20	35
7	12	5	17	29.41
8	16	2	18	11.11
9	14	3	17	17.65
10	24	8	32	25
11	23	7	30	23.33
12	13	8	21	38.10
13	11	3	14	21.43
14	10	3	13	23.08
15	14	1	15	6.67
16	18	0	18	0
Total	252	73	325	22.5

OT – Operation theater

Table 7

Stated reasons for cancellations

Reason for cancellation	Number	Percent (%)
Lack of operating time	57	78.1
Patient unfit	6	8.2
Patient absent	3	4.1
Work-up pending	3	4.1
Patient non-fasting	3	4.1
Scheduling error	1	1.4
Total	73	100

Discussion

Keeping the OT scheduled to satisfy all the various constituents is a complex dynamic process. There is restriction of operating time at the hospitals as no elective operations are performed on Sundays and on public holidays. The health care environment needs to be carefully analyzed to ensure that the services the OT offers are appropriate.

An audit of surgical theater utilization by Vinukondaiah et al.[1] reported a mean of 10 h 31 min of operating time/day, amounting to 91.5% of total available operating time. Two percent of the total available time was spent on interval between cases. In our study, the adjusted utilization was a mean of 413 min/day, accounting for 86.9% of the total resource hours, which is comparable to the previous study. In a study on time utilization of operating rooms at a large teaching hospital by Jan et al.,[7] of the utilized time, time spent on actual surgery was found to be 66.02%, time spent on supportive services was found to be 21% and time spent on making the room ready was found to be 12.9%.

Another study by Haiart et al.[8] showed that 25% of theater sessions were not allocated for use, 23% of general surgical lists were cancelled and of the lists that did take place, a further 23% of theater time was not utilized. The single largest cause of underutilization was understaffing. They suggested that to increase theater utilization, higher levels of staffing and expenditure are needed rather than changes in the working practices of surgeons. Of the 283 hours of allocated theater time, 218 h and 19 min (77.1%) were utilized, which included anesthetic induction time and operating time.

Vinukondaiah et al.,[1] showed that 43.6% of the lists started later than the scheduled time. From these 43.6% delays, 80.4% of the time the delay was due to late shifting of the patient to the OT and 17.1% of the time the delay was due to an emergency surgery from the previous night continuing beyond 8.00 am. In the remaining 2.5% of time, the delay was because of miscellaneous causes. In our study, there were delays on 15 occasions of 96 lists, i.e. 15.63%, and late shifting of the patient from the ward to the OT was the most common (44.66%) cause. In a study by Kumar and Sarma,[9] none of the residents felt that there is a delay in start of OT, yet majority of the consultants and 35% of the nurses felt that OTs were starting late and the most common reason stated was delay in shifting of patients to OTs from wards. Delay in readiness of other equipment was also an important reason mentioned.

In most facilities, room turnover time represents 10-20% of the total case time.[5] A review at four academic institutions indicated that turnover times ranged from 34 to 66 min.[10] Kumar and Sarma[9] in their study cited that the average clean-up time of all OTs ranged between 10 and 15 min. In our study, the percentage mean room turnover time was 5.39% (25.86 min) of the total available resource hours. Jan et al.[7] reported that room turnover time was on an average 14.1 min. In an audit by Vinukondaiah et al.,[1] about 5 min was taken as the maximum permissible interval between cases. Interval between cases was a mean of 3 min and 13 s. Two percent of the total available time was spent on interval between cases. This variability in different studies could be attributed to patient factors (septic burns, HIV or HBsAg positive), number of cancellations and certain logistic factors that may delay the shifting of the next case.

In a study by Kumar and Sarma,[9] due to unrealistic scheduling and shortage of OT time, nearly 26% of the total cases posted in all the OTs were cancelled. The single most important cause for the cancellation was found to be “time factor” due to restriction of general anesthesia time. In our study also, the most common reason for cancellation was lack of operating time (78.1%) due to restriction of general anesthesia time, while the overall cancellation rate was 22.5% (73/325 cases).

In a study by Garg et al.[11] 30.3% cancellations were reported on the day of surgery. The reasons for cancellation of the scheduled elective cases were 59.7% due to lack of availability of theater time, 16.2% did not turn up on the day of surgery, 10.8% because of medical reasons, 5.4% due to a change in the surgical plan and 3.7% because of administrative reasons (autoclaved instruments/linen not available, instruments not available), and miscellaneous reasons (no availability of senior surgeon for the case, ICU bed/ventilator, adequate blood products and refusal of consent by patient) were responsible for 4.2% of cancellations.

Schofield et al.[12] in their study at a major hospital in Australia reported 941 (11.9%) cancellations out of 7913 theater sessions. The reasons included no bed available (18.9%), run out of theater time (16.1%), patient non-arrival (10.5%), patient unfit (9.2%) and cancelled by patient or relative (8.2%). In our study, there were no cancellations because of unavailability of bed or by patient/relative. 4.1% of the cancellations were due to non-arrival of the patient and 8.2% due to lack of fitness.

An audit study of OT utilization by Vinkondaiah et al.[1] cited 310 (14.3%) cancellations. Two hundred and two (65.2%) cases were cancelled due to lack of time, 43 (13.9%) due to emergency surgeries during elective list and 35 (11.3%) due to lack of fitness.

Another prospective study by Sanjay et al.[13] in 2007 titled “Cancelled elective operations: An observational study from a district general hospital” demonstrated that 14% of elective operations were cancelled. Fifty-one percent of the cancellations were due to patient-related reasons, 34% were cancelled for non-clinical reasons and 15% were cancelled for clinical reasons. The common reasons for cancellation were inconvenient appointment (18.5%), list over-running (16%), the patient thought that they were unfit for surgery (12.2%) and emergencies and trauma (9.4%).

Delay in starting the OT table on time leads to inefficient utilization of available resource hours. It can be reduced by improving communication between patient and surgeon (so that the patient knows the pre-operative instructions properly) and between OT nurses and ward nurses (for smooth shifting of elective surgery indoor patients from wards to OT). The number of cancellations can be reduced by proper scheduling of cases. Appointment of an OT manager may help adequate scheduling of cases for various OT tables, thereby reducing cancellation of cases and improving utilization of OT tables.

To assess OT utilization, a study of utilization of available resource hours is an important tool. Such a study indicates the factors that need to be improved for optimal utilization of the available operating time. Variability of case duration also makes it difficult to predict the actual utilization. Even for routine operations, actual case time is uncertain. Each patient is different, and the actual time for a given operation cannot be predicted. This means that in a series of cases that are scheduled to follow, the actual time of cases after the first case cannot be anticipated. If scheduling of cases is done according to the available resource hours and communication between pre-operative personnel, i.e. patients, surgeons, nurses, anesthesiologists etc., is improved, the efficiency of OTs may be improved. Additional audits similar to this are required to critically analyze the utilization of available resource hours, keeping in mind the variability of case-mix.