Preoperative Warming Up Exercises Improve Laparoscopic Operative Times in an Experienced Laparoscopic Surgeon

Introduction

W arming up before a musical concert, athletic competition, or other highly skilled tasks is very common and has been shown in a number of studies to improve overall performance. ^1,2 Many surgeons will routinely “mentally warm up” by envisioning the type of surgery or surgical procedure they are about to perform. This exercise has been shown in a number of studies to improve surgical performance. ^{3 –5} Although surgery is a very highly skilled task, many surgeons do not routinely “physically warm up” with surgery-related tasks before an operation. This occurs despite a small but growing body of evidence that physically warming up before surgery can improve performance in the operating room. ^6,7

As the demand for accountability and performance-based initiatives are entering into the healthcare landscape, methods to improve surgical performance and outcomes should be examined. These methods, such as mentally or physically performing surgically related tasks before operating, could improve performance and outcomes in novice and advanced surgeons. We examine the effects of a simple preoperative warm-up (WU) routine on patient outcomes and operating room parameters in an experienced laparoscopic surgeon.

Methods

A retrospective review of all laparoscopic partial (LPN) and radical nephrectomies (LRN) completed by one experienced laparoscopic surgeon (RVC) were analyzed according to whether WU exercises were performed before surgery. All procedures were performed from June 2005 to July 2009. Routine WU consisted of 15 to 20 minutes of pelvic trainer suturing exercises. This was performed using both hands and included forehand and backhand sutures and knot tying. Before July 2007, the surgeon did not warm up for planned LPN or LRN. Starting in July 2007, a planned WU was performed before LPN or LRN. Cases of LPN (n=13) and LRN (n=29) without WU from June 2005 through July 2007 were compared with cases of LPN (n=16) and LRN (n=17) with WU from July 2007 to July 2009. Only cases in which the major portion of the procedure was performed by the primary surgeon or first start cases were included in the analysis.

Intraoperative parameters, including total operative time, surgical time, estimated blood loss, warm ischemia time, complications, and positive margin rates, and postoperative parameters, including total length of stay, changes in postoperative hemoglobin and creatinine levels, were analyzed. Morphine equivalents were also calculated for patients after reviewing all narcotics administered after postoperative day 1 as well as determining the number of patients who needed patient-controlled analgesia (PCA) for pain control. A weighted average cost per minute of operating room time was calculated for fiscal year 2010 using departmental, anesthesia, and costs of implants for LRN and LPN.

Data were analyzed using unpaired Student t tests, and the Fisher exact test where appropriate. All statistical analyses were performed using STATA software, version 9.0 (Stata Corp, College Station, TX).

Results

The WU group and nonwarm-up (NWU) group in the LRN cohort were well matched in terms of age at surgery, sex, tumor size, American Society of Anesthesiologists (ASA) classification, and body mass index (BMI). As summarized in Table 1, the WU group had a significantly shorter total operating room time by 53.9 minutes (P=0.0103) and significantly shorter surgical time of 47.2 minutes (P=0.0208). Changes in serum electrolyte and blood parameters were not significantly different between each group, and the overall length of stay was also not significantly different. The percentage of patients who underwent concurrent adrenalectomy was not different between the groups NWU=71% vs WU=81%, P=0.283), and there was no statistically significant increase in operative time when an adrenalectomy was included in the procedure.

The percentage of patients who needed PCA postoperatively (NWU=28% WU=12%, P=0.119) and narcotic used in morphine equivalents between the two groups was also not statistically significantly different, although there was a trend for less narcotic use in the WU group (14.5+15.2 mg vs 7.91+9.5 mg, P=0.266).

The clinical parameters for the LPN group are summarized in Table 2. The LPN groups were also well matched in terms of age at surgery, sex, ASA classification, and BMI. Tumors were significantly larger in the WU group by approximately 1.54 cm (2.44±0.67 vs 3.99±2.04, P=0.015). Again, surgical times were significantly shorter in the WU group compared with the NWU group (281.92 min vs 227.13 min, P=0.0038), and a decrease in the total operating room time trended toward significance (P=0.0501). Warm ischemia time, estimated blood loss, changes in postoperative serum parameters, and total length of stay were not statistically significantly different between the two groups. The percentage of patients who needed PCA for pain management and the morphine equivalents needed after postoperative day 1 to discharge were also not statistically significantly different between the groups (NWU=33% vs WU=20%, P=0.662, and 9.58±9.41 mg vs 6.72±10.18 mg, P=0.534, respectively).

Overall intraoperative complications (any event that deviated from the primary operation) rates in the LRN and LPN were low precluding any robust statistical analysis among the WU groups (LRN=three complications, LPN=three complications). When using a weighted average for operating room costs per minute, the saving incurred by the decreased operating room times in the LRN would have amounted to, on average, approximately $2230.92 and $2201.53 in the LPN.

Discussion

The concept of warming up before a performance in sports, theater, and other skill-based activities is well established. ^8,9 Only recently have researchers begun to examine the effects of preoperative WU directly on surgical performance and outcomes. This article is one of the first to report a direct improvement in measurable operating room efficiency after performing WU exercise before complex laparoscopic surgery.

There are very few studies that look directly at the impact of preoperative WU and surgical outcomes. One of the first includes Calatayud and associates, ⁶ who examined the impact of performing laparoscopic tasks on a virtual reality simulator immediately before performing a laparoscopic cholecystectomy. They found that surgeons who performed approximately 15 minutes of WU on a simulator just before surgery had significant improvement in objective structured assessment of technical skills global rating scores compared with those who did not warm up. This study, however, did not examine the effects of WU on operative time or postoperative outcomes.

Kahol and colleagues ⁷ examined the effects of WU in a virtual reality simulator on performance of surgically related tasks in the laboratory setting. WU resulted in an improvement in surgical skill proficiency that was noted across all levels of surgical training. It even helped reduce errors related to postcall fatigue. Finally, Do and coworkers ¹⁰ demonstrated that 15 minutes of basic skill task WU exercises on a laparoscopic pelvic trainer significantly improved the subsequent time to perform the same tasks in obstetrics/gynecology residents and medical students. These studies were limited to the laboratory and used the same simulator for WU practice and evaluation of the surgical tasks.

This is the first study to look directly at the impact of preoperative WU on patient outcomes. In our series, the 15 to 20 minutes of WU resulted in an average decline of just approximately 50 minutes of operating room time in the LPN and LRN groups. Although other measures of outcomes, such as length of stay, narcotic use, warm ischemia time, blood loss, and changes in serum parameters were not different between the groups, this study suggests that a WU period improves operating room efficiency even in an advanced laparoscopic surgeon, and thus may significantly impact both the cost of hospitalization and the patient safety/outcome with regard to amount of time under anesthesia. ^{11 –13} Using a weighted cost average for LRN and LPN at our institution, the decline in operating room times resulted in more than $2000 in cost savings per procedure for the hospital or more than $60,000 in the 2 years that WU was initiated. Finally, less surgical and anesthesia time has been shown to significantly reduce postoperative complications in a number of previous surgeries. ^{11 –13}

There are several limitations to this study. One is the retrospective nature of the data collection. This is also a single surgeon series. The impact of the various trainees who were involved in the procedure cannot be determined, as well as other factors that could have impacted operating room times (operating room staff, anesthesia staff, sleep deprivation in the surgeon or assistant, etc); however, at our hospital, there is a dedicated urology laparoscopy team that would have participated in more than 90% of the procedures, which could limit some of the external factors that influence times in the operating room. The study also does not identify the specific parts of the procedure in which operative times improved in the WU group or if there was a reduction in the number of intraoperative errors. Warming up could help with some of the earlier less critical tasks, while the more complex portions of the surgery, such as dissecting the hilum or resecting the tumor, may not be affected by the WU period because the surgeon would have gone through the WU during the initial part of the procedure.

Despite the limitations, this singular study suggests that even in an advanced laparoscopic surgeon, warming up can have some benefits to surgical efficiency. It could potentially impact on the adverse effects of prolonged anesthesia for the patient. Finally, it could reduce operating room costs by decreasing anesthesia time and total time spent in the operating room. Whether preoperative WU can improve overall surgical outcomes and reduce intraoperative errors among experienced laparoscopic surgeons remains undetermined in this study.

Conclusion

Preoperative WU appears to improve procedural efficiency when performing complex laparoscopic procedures in an experienced laparoscopic surgeon.