Patient Safety Tip of the Week

December 30, 2014

Data Accumulates on Impact of Long Surgical Duration



You’ve seen it at your facilities: surgeons blame late OR starts and long cases on the anesthesiologists taking too much time and anesthesiologists blame the surgeons for showing up late for cases and taking too long to operate. And those perceptions actually confound each other because the assumption that one or the other will be late may actually cause surgeons and anesthesiologists to delay! And neither are very good at predicting how long a case will actually take.


Yet another study has demonstrated a disparity between the ability of surgeons and anesthesia personnel to predict procedure duration and the actual duration of the procedures (Travis 2014). The researchers found that general surgeons in a New Zealand hospital underestimated the time required for the procedure by 31 minutes. Plastic surgeons underestimated by 5 minutes but orthopedic surgeons actually overestimated by 1 minute. Interestingly, anesthetists underestimated by 35 minutes. The authors conclude that the inability of clinicians to predict the necessary time for a procedure is a significant cause of delay in the operating room but there are potential differences between specialties.


Yes, such misperceptions of procedure times do wreak havoc with efficient operating room scheduling and throughput. They probably also lead to problems in teamwork and communication and morale. But we are most concerned about the potential impact for this time disparity from a patient safety perspective.


We’ve already discussed the issue in several prior columns (see our Patient Safety Tips of the Week for August 26, 2014 “Surgeons’ Perception of Intraoperative Time” and March 10, 2009 “Prolonged Surgical Duration and Time Awareness” and our January 2010 What’s New in the Patient Safety World column “Operative Duration and Infection). There are a variety of adverse events that can potentially occur when surgical cases go past their anticipated times.


One such potential adverse event is the occurrence of venous thrombembolism (VTE). Most of us have assumed over the years that longer surgical procedures were associated with increased risk of deep venous thrombosis (DVT) and pulmonary embolism (PE). In fact, we have long recommended that the operative team discuss either during the pre-op huddle/briefing or the surgical “timeout” the expected duration of the procedure and what contingencies should be considered if a certain duration is exceeded. But, much to our surprise, there really had never been a high quality study looking quantitatively at the relationship between surgery duration and VTE risk. Now a new study has done just that (Kim 2014). The researchers, using data from the American College of Surgeons National Surgical Quality Improvement Program on over 1.4 million patients undergoing surgery with general anesthesia, found an association between surgical duration and VTE that increased in a stepwise fashion. Compared with a procedure of average duration, patients undergoing the longest procedures experienced a 1.27-fold increase in the odds of developing a VTE event.


Another recent study looked at duration of surgery as a possible risk factor for complications in neurosurgery (Golebiowski 2014). The authors did a review of 1,000 consecutive patients who underwent planned surgery for intracranial tumors at a single institution. They found that duration of surgery together with comorbidity and acquired neurological deficits is an independent risk factor for extracranial complications after brain tumor surgery. Duration of surgery was also associated with surgical site infections. The odds ratio for extracranial complications with duration of surgery per hour was 1.14. The authors note that awareness of the harms of prolonged surgery may help neurosurgeons in planning approaches and equipment and should be considered in regards to training aspects. They also note that, in view of this association between case duration and complications, any potential prolongation of cases for research purposes should be discussed as part of informed consent.


Another study used American College of Surgeons National Surgical Quality Improvement Program data to evaluate the impact or surgical duration in patients who underwent lumbar fusion procedures (Kim, BD et al 2014). They demonstrated that increasing operative time was associated with step-wise increase in risk for overall complications, medical complications, surgical complications, superficial surgical site infection, and postoperative transfusions. Operative duration of 5 hours or more was also associated with increased risk of reoperation, organ/space surgical site infection, sepsis/septic shock, wound dehiscence, and deep vein thrombosis. The editorial accompanying this study, however, urges caution in attributing too much to surgical duration (Pearson 2014). It notes that the reasons for longer cases, including patient-related factors and technical factors, may not have been adequately accounted for in the analysis even though Kim et al. had used multivariate risk-adjusted regression models.


A previous study on risk for postoperative pulmonary complications found that surgical duration of at least 2 hours was one of seven independent risk factors for such complications (Canet 2010). The authors developed a risk index based on these seven objective, easily assessed factors and suggest the index can be used to assess individual risk of postoperative pulmonary complications and focus further research on measures to improve patient care.


Our March 10, 2009 Patient Safety Tip of the Week “Prolonged Surgical Duration and Time Awareness” discussed time unawareness during many surgeries. In addition to the potential impact on infectious complications, we noted that there are other potential patient safety issues related to prolonged surgical duration such as DVT, decubiti, hypothermia, fluid/electrolyte shifts, nerve compression, compartment syndromes, and rhabdomyolysis. Long-duration cases also increase the likelihood of personnel changes that increase the chance of retained foreign objects or retained surgical items (see our August 19, 2014 Patient Safety Tip of the WeekSome More Lessons Learned on Retained Surgical Items”). And the fatigue factor comes into play with longer cases, increasing the likelihood of a variety of other errors.


Surgical case duration is also one of the few modifiable risk factors for surgical infections. A number of studies in the past have demonstrated an association between perioperative infection and the duration of the surgical procedure. In our January 2010 What’s New in the Patient Safety World column “Operative Duration and Infection” we noted a study (Proctor et al 2010) which found the infectious complication rate increased by 2.5% per half hour and hospital length of stay (LOS) also increased geometrically by 6% per half hour.


In our September 29, 2009 Patient Safety Tip of the Week “Perioperative Peripheral Nerve Injuries” and our May 2011 What’s New in the Patient Safety World column “ASA Updates Advisory for Prevention of Perioperative Peripheral Neuropathies” we discussed duration of procedures and position in causing compressive nerve injuries. A recent study (Delaney 2014) noted that total operative time was one of two predictors of postoperative brachial plexus deficits after the Latarjet shoulder procedure.


And remember – it is not just human factors that lead to long surgical cases. There may be system issues as well. In our August 26, 2014 Patient Safety Tip of the Week “Surgeons’ Perception of Intraoperative Timewe noted many factors that may lead to increased surgical durations, including case type and complexity, emergency vs. elective nature, patient-related factors, proficiency of the surgeon, lack of team familiarity, interruptions, equipment issues, presence of trainees and poor communication. Obviously patient-related issues are important. For example, a recent study (Bradley 2014) showed that for total joint replacement each 5-point increase in patient BMI increased operative time by 7 minutes. Unanticipated complications (bleeding, anomalous anatomy, etc.) may occur as well. Even if you do a great job planning in your pre-op huddle/briefing there are always potential contingencies that arise. A key piece of equipment might break or get contaminated, necessitating a delay to get a replacement.


Some have advocated for estimates of and discussions about anticipated surgical duration during the surgical “timeout”. We think that is too late and not the best opportunity for that discussion. Rather, we recommend that the OR team, during the presurgical huddle/briefing, should discuss issues related to prolonged cases. For example, they should discuss whether intraoperative DVT prophylaxis should begin if the procedure lasts beyond a certain duration. Or discuss at what duration a repositioning of the patient might be wise to avoid nerve compression, compartment syndrome, or rhabdomyolysis. And it would be very useful to have an estimate of time remaining to again trigger some discussion on the above issues. In addition to the DVT prophylaxis and repositioning issues, it might raise questions about the need to temporarily ease up on traction. It might direct attention to maintenance of the patient’s body temperature. In a very prolonged case it might raise questions about the need for further doses of prophylactic antibiotics. So good communication begins before the patient has actually entered the OR and is necessary throughout the case to ensure more efficient and safe performance of surgery. (And don’t forget that the postop debriefing may help you save time during your next case as well!)


In our July 22, 2014 Patient Safety Tip of the Week “More on Operating Room Briefings and Debriefings (and other columns) we noted some of the issues that might be discussed in a pre-op briefing/huddle (plus we’ve added some questions that came from last week’s column Iatrogenic Burns in the News Againon iatrogenic burns related to warming devices):


But beware you don’t make the process too complicated. Your pre-op briefing should probably take no more than about 2-3 minutes. Be sure to customize them. A briefing for an orthopedic surgery case is likely to be significantly different than one for a gynecological procedure.


We also recommend that someone in the OR, usually the anesthesiologist, be tasked with calling out the running case duration at regular intervals (for example, every 30 minutes and more often as the case approaches the average duration for similar cases). That makes everyone aware of the issues that may need to be considered in cases that are taking longer than expected. The announcement of the duration should be accompanied by announcement of pre-agreed-upon actions (for example, a second dose of antibiotics or a change in patient positioning).


In our August 26, 2014 Patient Safety Tip of the Week “Surgeons’ Perception of Intraoperative Time” we noted no one is happy when surgical cases take too long. There are safety issues, as noted above, for the patient. Staff dissatisfaction increases. Other patients and surgeons become disappointed if their subsequent case has to be cancelled (and that next patient’s employer becomes unhappy if he/she has to take a second day off from work). Your surgical scheduling becomes chaotic. Your hospital or facility may suffer financially due to unexpected overtime costs and lost opportunity costs (for other cases that might have been done).


So make surgical case duration an issue of importance for your organization. Make sure you keep good data on duration of all cases, major and minor, and actually utilize that data during scheduling. Do your pre-op huddles/briefings and post-op debriefings in all cases. And make intraoperative time awareness part of your regular OR routines.



Our prior columns focusing on surgical case duration:



See our prior columns on huddles, briefings, and debriefings:







Travis E, Woodhouse S, Tan R, et al. Operating theatre time, where does it all go? A prospective observational study. BMJ 2014; 349: g7182



Kim JYS, Khavanin N, Rambachan A, et al. Surgical Duration and Risk of Venous Thromboembolism. JAMA Surg 2014; Published online December 03, 2014



Golebiowski A, Drewes C, Gulati S, et al. Is duration of surgery a risk factor for extracranial complications and surgical site infections after intracranial tumor operations?

Acta Neurochirurgica 2014; Date: 02 Dec 2014



Kim BD, Hsu WK, De Oliveira GS, et al. Operative Duration as an Independent Risk Factor for Postoperative Complications in Single-Level Lumbar Fusion: An Analysis of 4588 Surgical Cases. Spine 2014; 39(6): 510-520



Pearson A. Duration of Surgery: Independent Risk Factor for Complications? The Spine Blog March 28, 2014



Canet J, Gallart L, Gomar C, et al. Prediction of Postoperative Pulmonary Complications in a Population-based Surgical Cohort. Anesthesiology 2010; 113(6): 1338-1350



Procter LD, Davenport DL, Bernard AC, Zwischenberger JB. General Surgical Operative Duration Is Associated with Increased Risk-Adjusted Infectious Complication Rates and Length of Hospital Stay, Journal of the American College of Surgeons 2010; 210: 60-65



Delaney RA, Freehill MT, Janfaza DR, et al. Neuromonitoring the Latarjet Procedure. Journal of Shoulder and Elbow Surgery 2014; 23(9): e229–e230 Published in issue: September, 2014



Bradley BM, Griffiths SN, Stewart KJ, et al. The Effect of Obesity and Increasing Age on Operative Time and Length of Stay in Primary Hip and Knee Arthroplasty. J Arthroplasty 2014; 29(10) 1906–1910





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