In our study, an analysis of surgical procedures was carried out and the mortality was estimated in procedures of varying complexity, from exploratory laparotomy to elective hernioplasty. Many of the interventions (92.8%) were emergency surgery, which represents a risk factor for 30-day mortality.
The emergency procedures present significant numbers. In the United States, for example, there is an annual mean of around 3 million emergency surgeries carried out7. In this context, Reinke et al., carried out a study assessing hospitalization for non-cardiac general surgery8. The most common surgical procedures were cholecystectomy, wound debridement, partial resection of the small intestine and appendectomy, while in our study the most prevalent were exploratory laparotomy, cholecystectomy, appendectomy and wound debridement of perineal abscesses. A correspondence was verified between the cases in our study and those reported in others with similar risk factors and comorbidities8,9.
Despite the higher number of patients with high cardiovascular risk, the mortality obtained in the American study in patients submitted to emergency surgery was 3.8%9, a much lower number than that found in our study. This contrast could be due to the severity of the conditions the patients presented in our center and the elevated rate of acute mesenteric ischemia (AMI). With 53 occurrences, this diagnosis was responsible for 52.7% of the mortality in our study.
AMI is caused by a sudden interruption of the blood supply for a segment of the small intestine, causing ischemia, cellular damage and intestinal necrosis. Most cases are caused by embolic occlusion (40 to 50%) or by thrombotic occlusion (25 to 35%). Mesenteric embolisms are associated with cardiac complications such as atrial fibrillation, left ventricle myocardial dysfunction and reduced ejection fraction or cardiac valves damaged by endocarditis. AMI is an uncommon cause of abdominal pain, corresponding to less than 0.1% of hospitalizations in a general hospital, but its mortality is between 60 to 80%10.
In a recently published article, Gilshtein et al. identified 63 patients with ischemic colitis, the most common form of AMI, in one tertiary center11. Most patients were treated clinically, and only the 20% most serious cases, with complications such as peritonitis, hemodynamic instability and untreatable disease, received surgical intervention. These patients had a mortality of 50%, lower than our study (71.7%), which reinforces the gravity of the condition of the patients referred to the center in our study.
From our statistical analysis it was possible to estimate that for AMI, mortality occurs until a mean of 11 days, which represents more than 90% of the deaths from this condition. This information could affect the management of the patient, as it defines the phase of greatest risk.
Another diagnosis that was relevant to our study was the perforated peptic ulcer. Complications of the ulcer, as well as perforation, include bleeding and obstruction. When perforated, the ulcer must be referred to emergency surgical treatment, and is associated with a 30% mortality rate in 30 days 12,13. Among our patients, a significantly higher mortality rate of 66.7% was observed, probably due to the severity of the condition of patients referred to the center. Furthermore, it was possible to identify that patients tended to die up to the 12th postoperative day. The large CI of 95% (between 5 and 20 days) was a result of our small sample with just 9 patients.
Acute cholecystitis and acute appendicitis were also highly prevalent in our study, but the 30-day mortality of both was low, which resulted in a survival curve with little predictive value.
Similarly, the other diagnoses did not collect enough cases, which shows a need for other studies with a larger sample of patients to obtain significant results. This would allow the period of greatest risk to patients to be identified, and allow care to be tailored accordingly, as with AMI.