Acute appendicitis is one of the most commonly encountered surgical emergencies today. Given the ubiquitous nature of the condition, however, it has also become one of the most commonly postponed surgical procedures.

Increasing the interval between emergency department (ED) admission and appendectomy has been shown to increase the development of advanced appendicular pathology, as well as increasing post-operative complications, length of stay and overall cost to the hospital service.^1,2,3

Prior research in the mid to late 1990s suggested that a ‘wait and see’ approach could be beneficial for patients with suspected appendicitis,⁴ however more recent work has debunked this notion and has shown the importance of prompt treatment of this common yet significant surgical pathology.

Objectives

The objective of this audit was to determine whether significant delays were occurring between patient admission and appendectomy time. Furthermore we aimed to elucidate whether these delays, if any, were comparable to international figures.

Standard

No single international standard exists for the interval between admission and procedure in acute appendicitis. In this audit we used several relevant studies identified from the literature to produce a de facto standard. Through our literature review we observed a common finding that an interval time of greater than 24 hours^2,3 from ED admission was a statistically significant predictor of poor post-operative outcomes. Some evidence suggests that 12 hours is the ‘watershed’ interval,¹ but for this audit we have used an interval time of < 24 hours as our benchmark.

Complication rates were compared against reported figures from a 32,683-patient study by Ingraham et al,⁵ which reported a total morbidity rate of 4.5% for laparoscopic procedures and 8.8% for those performed following a laparotomy.

The rate of negative histology was measured against a paper by the SCOAP collaborative,⁶ which looked at 3,540 patients to review the rate of negative histology following either computed tomography (CT) or ultrasound (U/S) imaging. See Table 1 for a summary of these sources.

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Methods

A retrospective analysis was performed on 50 patients who underwent an appendectomy for acute appendicitis at Midlands Regional Hospital, Portlaoise, between December 2012 and September 2013. Patients were identified using the theatre register and computerised filing system. Charts were retrieved from medical records and reviewed by hand. Patients were split into two groups, with patients operated on in less than 24 hours being placed in the ‘early appendectomy’ (EA) group, and those waiting longer than 24 hours placed in the ‘delayed appendectomy’ (DA) group.

All data were collected using an audit proforma. Pre-operative data extracted from patient charts included: age, admission date, admission time, procedure date, procedure time and incidence of complications. Pathology was recorded as positive or negative as per histopathological reports or, where this was not available, the result was based on a senior surgeon’s intra-operative impression. Post-operative data extracted from patient charts regarding complications was recorded as present or absent. In the presence of either negative histology or postoperative complications, the patient’s clinical details were recorded.

Data were maintained and analysed on an Excel spreadsheet. All data were anonymised and stored according to HSE guidelines. Averages are expressed as arithmetic means, standard deviations and, where appropriate, are followed by the range (A-Z).

Results

A total of 50 patients were included in the audit and full audit proforma information was available for all patients.

Interval time

There were 21 males and 29 females. The average age was 23.04 ± 13.14 years (2-61), 14 were children (< 15 years). There were 25 (50%) patients in the EA group and 25 (50%) patients in the DA group. The overall average interval time was 21.06 ± 20.85 hours (1-96).

Open versus laparoscopic

Open appendectomy (OA) was performed on 12 (24%) patients and laparoscopic appendectomy (LA) was performed on 38 (76%) patients. In the EA group there were seven OAs performed and 18 LAs. In the DA group there were five OAs performed and 20 LAs.

Histology

Overall there were 38 (76%) cases with positive histology. All of the remaining 12 (24%) patients had some degree of surgical or gynaecological pathology present intra-operatively (10/12) or appeared inflamed intra-operatively (2/12). See Table 2 for the clinical details of these patients.

Complications

There was one (2%) post-operative complication overall, in the EA group.

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Discussion

Overall the interval times audited do not compare favourably with international benchmarks. Despite a relatively small sample size of 50 patients, it is evident that a large proportion of patients with suspected appendicitis are having their treatment delayed beyond 24 hours. As contemporary research would show, this is a potentially dangerous practice which not only increases the risk for negative outcomes, but also increases the financial burden on hospital services. Increasing theatre availability outside of normal working hours would help in alleviating this problem.

In relation to post-operative complication rates, our figures compare favourably with international recommendations (2% versus 4.5%). Turning to histology, there was a 24% negative histology rate, considerably higher than the standard of 8.1%. However, 10 of these cases had intra-operative findings of pathology other than appendicitis, which could explain the decision to operate. 

Making a conservative assumption that the two remaining cases were the only two true negative appendectomies, our negative histology rate becomes 4% – well under the benchmark cited by the SCOAP Collaborative.²

Limitations

This was a retrospective analysis, and so cannot account for specific clinical indications which may have driven the decision to operate in certain cases.

Secondly, the design of an audit as a benchmarking tool prevents its use in the analysis of relationships, if any, that exist between the variables mentioned. Further research is warranted in this area to determine if these delays are a predictor of poorer outcomes in our patient population.

Recommendations

Following this audit, the authors made the following recommendations: 

• To explore the feasibility of increasing theatre availability
• To focus on improving NCHDs’ diagnostic skillset.

References

1. Busch M, Gutzwiller FS, Aellig S et al. In-hospital delay increases the risk of perforation in adults with appendicitis. World J Surg 2011 Jul; 35(7): 1626-33 
2. Cuschieri J, Florence M, Flum DR et al. Negative appendectomy and imaging accuracy in the Washington State Surgical Care and Outcomes Assessment Program. Ann Surg 2008 Oct; 248(4): 557-63
3. Eldar S, Nash E, Sabo E et al. Delay of surgery in acute appendicitis. Am J Surg 1997 Mar; 173(3): 194-8
4. Ditillo MF, Dziura JD, Rabinovici R. Is it safe to delay appendectomy in adults with acute appendicitis? Ann Surg 2006 Nov; 244(5): 656-60
5. Giraudo G, Baracchi F, Pellegrino L et al. Prompt or delayed appendectomy? Influence of timing of surgery for acute appendicitis. Surg Today 2013 Apr; 43(4): 392-6
6. Ingraham AM, Cohen ME, Bilimoria KY et al. Comparison of outcomes after laparoscopic versus open appendectomy for acute appendicitis at 222 ACS NSQIP hospitals. Surgery 2010 Oct; 148(4): 625-35; discussion 635-7