Patient Safety Tip of the Week

August 15, 2017

Delayed Emergency Surgery and Mortality Risk



It’s well known that delays in performing surgery for hip fracture increase patient morbidity and mortality. But the relationship has been less well defined for other types of emergency surgery. Now Canadian researchers have published a new study that sheds light on the impact of delays for all types of emergency non-cardiac surgery (McIsaac 2017). McIsaac and colleagues at Ottawa Hospital analyzed cases where surgery for emergency cases was delayed compared to those performed without delay. They found that 18.6% of over 15,000 emergency cases between January 2012 and October 2014 experienced a delay. They found that in-hospital mortality in delayed cases was 4.9% compared to 3.2% in those without delay. They then did matching based on propensity scores in attempt to account for confounding variables other than delays. That adjusted analysis revealed that delays were significantly associated with mortality (OR 1.56), increased length of stay (incident rate ratio 1.07), and higher total costs (incident rate ratio 1.06). The number needed to harm for mortality was 60.


Moreover, they found that system issues dominated the reasons for delay (accounting for over 86% of cases with documented reasons for delay). They found that availability of personnel was a common reason for delays. That unavailability was most often for the surgeon but occasionally also involved anesthesiologists or nurses. Availability of physical resources (operating room, post-anesthesia recovery unit, equipment) was also a common reason for delays. And many cases had multiple reasons for delay. Many cases were bumped by higher priority cases. Patient-specific reasons for delay were less common but usually involved medically complex or decompensated patients who needed stabilization prior to surgery.


You need to read the McIsaac article to understand the way they defined delays and how they classified degree of urgency. But suffice it to say that they determined an expected wait time for surgery for each type of surgery and its classified degree of urgency. They then found another very interesting trend. As wait time increased up to 1.1 multiples of the accepted wait-time window the odds of mortality increased. But for wait times beyond 1.1 multiples, the odds of mortality actually decreased. They thus postulated there may be two distinct subgroups of patients: those that truly need emergent surgery and those that have a survivorship bias.


A key point of the McIsaac article and the accompanying editorial (Urbach 2017) is that in allocating human and financial resources for the OR, we need to take a strong look at downstream costs. While fixing some of the system issues leading to surgery delays may be expensive, there may well be cost offsets in the long run (due to reduced length of stay and other costs).


At first blush, these findings might seem to contradict a point we made in our several columns on “after-hours” surgery (see the list below). In those columns we’ve discussed the multiple factors that may lead to less desirable outcomes when surgery is performed after-hours and in some of those columns we’ve intimated that many cases may be more safely performed the following morning rather than at night.


But the McIsaac study was not a study of time of day surgery was done. Rather, it looked at delays any time of day. And many of the system factors identified by McIsaac and colleagues leading to delays are also the same ones we’ve identified in after-hours cases.


So the conclusions by McIsaac et al. are not really contradictory to those in our prior columns. We are in agreement that there are multiple system issues that interfere with optimal care when emergent cases are either delayed or done after-hours. Attention to correcting those factors may lead to better outcomes.


In our October 4, 2016 Patient Safety Tip of the Week “More on After-Hours Surgery” we discussed why “after hours” surgery might be more prone to adverse outcomes than regularly scheduled elective surgery. There are many reasons aside from the fact that patients needing emergency and after hours surgery are generally sicker. For surgery, in particular, the impact of time of day on teamwork is important. You are often operating with a team that is likely different from your daytime team. All members of that team (physicians, nurses, anesthesiologists, techs, etc.) may not have the same level of expertise or experience as your regular daytime team (because many hospitals have “seniority” policies, you may have less experienced personnel on your OR “on-call” teams) and the team dynamics between members is likely to be different. The post-surgery recovery unit is likely to be staffed much differently after-hours as well. The staff may be more likely to be unfamiliar with things like location of equipment. And some of the other hospital support services (eg. radiology, laboratory, sterile processing, etc.) may have lesser staffing after-hours. Just as importantly, many or all of the “on-call” staff that make up the after-hours surgical team have likely worked a full daytime shift that day so fatigue enters as a potential contributory factor. And there are always time pressures after hours as well. In addition, one of the most compelling reasons surgery is done at night rather than deferred to the next morning is the schedule of the surgeon or other physician for that next morning (either in surgery or the cath lab or his/her office). Because the surgeon does not want to disrupt that next day schedule, he/she often prefers to go ahead with the current case at night. Similarly, many hospitals run very tight OR schedules and adding a case from the previous night can disrupt the schedule of many other cases.


The Urbach editorial (Urbach 2017) suggests that use of team-based surgical care models may be one way to address some of the system-level barriers to timely emergency surgery. Working in such teams may allow cross-coverage so that delays due to a single surgeon being occupied elsewhere are minimized. Obviously such models are best implemented at academic medical centers or larger urban hospitals and are more difficult to implement at rural or smaller community hospitals.


We highly recommend hospitals take a hard look at surgical cases done “after hours” and all your cases of “emergency” surgery. You need to look at the morbidity and mortality statistics of such cases. You need to identify factors contributing to delays in such cases and you need to determine which cases truly needed to be done after hours and, perhaps more importantly, which ones could have and should have been done during “regular hours”. If the latter are significant, you need to consider system changes such as reserving some “regular hours” for such cases to be done the following morning. You may have to alter the scheduling of cases for individual surgeons as well. For example, perhaps the surgeon on-call tonight should not have elective cases scheduled tomorrow morning. That way, if a case comes in tonight that should be done tomorrow morning you will have both a “free” OR room and a “free” surgeon. And you would need to develop a list of criteria to help you triage cases into “regular” or “after-hours” time slots.


The study by McIsaac et al. suggests that investment in personnel and system issues that may lead to delays in surgery are likely to be offset by downstream savings (in reduced length of stay and other costs).




Some of our previous columns on the “after-hours” surgery:

·         September 2009         After-Hours Surgery – Is There a Downside?

·         October 2014             What Time of Day Do You Want Your Surgery?

·         January 2015             Emergency Surgery Also Very Costly

·         September 2015         Surgery Previous Night Does Not Impact Attending Surgeon Next Day

·         October 4, 2016         More on After-Hours Surgery







McIsaac DI, Abdulla K, Yang H, et al. Association of delay of urgent or emergency surgery with mortality and use of health care resources: a propensity score–matched observational cohort study. CMAJ 2017; 189: E905-E912 published online July 10, 2017



Urbach DR. Delivering timely surgery in Canadian hospitals. CMAJ 2017; 189: E903-E904






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