Tipología de entrevistas

Number of articles excluded

Remaining articles included

Articles retrieved 4090

Exclusions on titles and abstracts

Not general surgery 3210 880

Elective surgery only 489 391

Paediatric population only 24 367

Developing world only 20 347

Exclusions on full text

Single disease 222 125

Single process of care only 34 91

Intra-operative care only 22 69

Inclusions from reference lists and “related articles” 37 106

Titles and abstracts of the articles retrieved by the search were downloaded to Endnote v6.0.1 (Thompson Reuters, New York, USA) and these were reviewed to see if they were relevant to quality and safety in emergency general surgery. A flow chart for reference selection can be found as Figure 3.2. The remaining references were reviewed in full text version and considered for inclusion. The remaining studies covered the entire gamut of emergency general surgery and consisted of

editorials, single centre cohort studies, multi-centre outcomes studies using large datasets and many other article formats. As such these studies could not be formally quality assessed because no

38 quality assessment criteria exist for many of these types of articles and because quality assessment primarily looks for risk of bias in randomised controlled trials, of which there was only one in the literature review and this was stopped early. For similar reasons a systematic amalgamation of data between studies (such as in meta-analysis or formal systematic review) was not possible. In addition, few studies actually addressed the same research questions as one another, a prerequisite for data synthesis. Due to these limitations the remaining 106 articles were assimilated and presented as a narrative review. Not all articles have been referenced in the text as all possible topics have not been covered. Suitable examples have been cited for each statement made and all relevant articles

included where data is reported.

3.2. Results of literature search

Improvements in outcome for EGS admissions are the ultimate goal for all who work in this field and, without an understanding of current performance, a detailed examination of underlying structure and process is difficult to put into perspective. For this reason this literature review, and the rest of this thesis, will consider the outcomes of EGS in the first instance, followed by an exploration of the structural and process factors that may explain or contribute to these outcomes.

3.2.1. Emergency general surgery outcomes

Mortality is the most frequently utilised outcome measure for EGS. This is appropriate for this high- risk group of patients as death rates are high enough to provide a useful data for most high-risk EGS diagnoses. Morbidity is also widely used but is limited by the lack of standardised definitions for many complications, the difference between post-operative atelectasis (lung base collapse without infection) and chest infection/pneumonia being a classic example. There is some debate over the use of length of stay and readmission rate for EGS patients. In many cases, length of stay is

dependent on the social circumstances and rehabilitation of the patient rather than the speed with which they recover from their disease (Mamidanna et al., 2010). While the readmission of EGS patients is often unwarranted, there are a number of conditions, for example small bowel

39 obstruction secondary to adhesions, in which successful non-operative management can be followed by a relapse within the 30 day period that is normally considered inappropriate. A final problem with the currently available data on EGS outcomes is that the majority of it is based on data sets that use an operation or group of operations as inclusion criteria. This approach only includes patients that surgeons have selected to undergo an operation and therefore is not necessarily an accurate representation of the outcomes for all EGS admissions.

The most frequently examined group of EGS patients is those who required an emergency colorectal resection. These operations are a sub-group of emergency laparotomies and are performed for obstruction, perforation, bleeding or ischaemia of the colon as a result of various disease processes. This is a useful group of patients to focus on because mortality for these procedures is high and they remain relatively common.

NHS Hospital Episode Statistics (HES) data demonstrates a 30-day, in-hospital mortality of 14.3% for patients undergoing emergency colorectal resection between 1996 and 2007 (Faiz et al., 2010b). This compares favourably with mortality from the American National Surgical Quality Improvement Project (NSQIP) hospitals of 15.4% between 2005 and 2007 (Ingraham et al., 2010a) (Table 3.1). Though this data has not been rigorously risk-adjusted, these papers suggest that the discrepancy in outcomes between the UK and USA in terms of elective mortality does not extend to emergency operations (Bennett-Guerrero et al., 2003). NSQIP participating hospitals are self-selecting and therefore the outcomes described by this program may not accurately reflect the outcomes of all hospitals in the USA (Almoudaris et al., 2011a). In addition, NSQIP only samples a selection of operations at each hospital and excluded some more minor procedures entirely, which may increase bias further (Khuri et al., 1998). In contrast, HES includes all hospitals in England and so avoids this selection bias. Post-operative complications are very common following emergency colorectal resection, occurring in almost half of patients (Ingraham et al., 2010a). Median length of stay in hospital is between 14 and 23 days, depending on diagnosis and the 28-day readmission rate is

40 between 6 and 14% (Faiz et al., 2010b)(Table 3.1). Survival at one year is similarly poor, with nearly 30% of patients dying within 12 months of their operation (Faiz et al., 2010b).

It is well recognised that age is a risk-factor for poor outcome following EGS operations and this is true for colorectal resections, where mortality is nearly 25% in patients over 70 years of age, rising to over 30% in those over 80 (Mamidanna et al., 2012). Length of stay and readmission rates do not seem to differ markedly from younger patients but mortality at 1 year for those over 70 years is 43% (Mamidanna et al., 2012).

Ingraham et al. examined outcomes for all EGS operations, though this includes large numbers of more minor procedures such as appendicectomy and abscess drainage (Ingraham et al., 2011a). This study of NSQIP data found an overall mortality of 6% and morbidity of 20% for EGS procedures compared to 1% and 9% respectively for elective operations (Table 3.1). The same group looked at similar operations in patients over 65 years of age and found a relative risk of death in those over 65 of 2.3 times, compared to the rest of the population (Ingraham et al., 2011c).