Non-Traumatic Abdominal Pain

A Retrospective Analysis of Secondary Data From 448 689 Cases Treated in Two Emergency Rooms in Berlin

Non-traumatic abdominal pain (NTAP) is one of the most common reasons for presentation to the emergency department (ED) (1, 2, 3). An understanding of demographic and clinical characteristics of patients with NTBS, the underlying diseases and the clinical course of treatment is critical to the targeted diagnosis and management of this condition in the ED (1, 2).

The aim of this study is to describe the demographic and clinical parameters as well as the clinical course and outcome of unselected patients with NTAP in two emergency rooms in the German city of Berlin.

Methods

In this retrospective study, we analyzed secondary data of two emergency departments for adult patients of the Charité—Universitätsmedizin Berlin, covering a period of 56 months (January 2015–August 2019).

The symptom NTAP was operationalized using the following clinical characteristics:

• Chief complaint “abdominal pain“ and/or
• Manchester Triage System (MTS) indicator “abdominal pain in adults” and/or
• ICD10 diagnosis R10 (abdominal and pelvic pain), based on the first diagnosis documented in the ED.

Patients with abdominal pain attributable to an injury based on the diagnosis made or the MTS presentational flow chart were excluded. Statistical analysis was performed using the SPSS software, version 27 (IBM). Group differences were assessed using chi-square test, t-test and logistic regression analysis. P-values were interpreted in an exploratory manner.

Results

Approximately 11.0% (n = 49 430) of a total 448 689 patients in the ED presented with NTAP during the observation period (Table 1). Comparing the individual years (2015: 10.7%, 2016: 11.1%, 2017: 10.9%, 2018: 11.3%, Jan-Aug 2019: 11.2%), only minor fluctuations were found. The majority of patients with NTAP in the ED were female (62.1%). The median age of patients presenting to the ED with NTAP was 38 years (women: 35 years versus men: 45 years; p<0.001), which was lower than that of patients presenting to the ED for other reasons (44 years).

Table 1

NTAP and other cases from the two EDs (CVK, CCM) of Charité—Universitätsmedizin Berlin during the period January 2015 to August 2019

The proportion of NTAP patients admitted for inpatient treatment was 25.8% (n = 12 769). Of those admitted as inpatients, 12.1% (n = 1 551) had to be treated in an intensive care unit one or more times over the course of their stay, and in-hospital mortality was 3.3% (n = 421). Significant differences between men and women were observed in the proportion of inpatient admissions (men: 32.9%; women: 21.5%; odds ratio [OR] 1.79; 95% confidence interval: [1.72; 1.86]; p<0.001), the proportion of intensive care treatment (men: 14.7%; women: 9.7%; OR 2.38; [2.14; 2.63]; p<0.001), and the in-hospital mortality rate (men: 4.0%; women: 2.6%; OR 2.35; [1.93; 2.85]; p<0.001).

Table 2 provides an overview of the most common diagnoses and the leading causes of death. Among outpatients with NTAP, the largest proportion of R10 diagnoses were symptom descriptions. Among inpatients, acute appendicitis (6.8 %) and pancreatitis (4.5 %) were the most common diagnoses. With 14.3%, sepsis was the most common primary hospital diagnosis among patients who died in hospital.

Table 2

Most frequent outpatient and inpatient diagnoses and most frequent causes of death of 49 090 patients with NTAP

Discussion

Of all persons presenting to the ED during the study period, approximately one in nine came because of NTAP (11.2%). This is in line with the results of other studies, reporting proportions between 10–12% (1, 2). However, the age in the patient population of this study is lower than previously described for Germany (1, 2). This may be explained by differences in ED catchment areas between this and other studies. Furthermore, differences in inpatient admission rates were found; with 25.8%, the rate shown in our study is comparatively lower. This could be attributable to differences in age. The in-hospital mortality of patients with NTAP was found to be 3.3%, which is significantly higher than, for example, the in-hospital mortality of patients with chest pain (0.9%) in comparable studies (1). In this context, sepsis plays an important role as the most common cause of death in patients with NTAP (14.3%). In light of the “golden hour of sepsis” (4), early detection and adequate treatment of patients with suspected sepsis is crucial in NTAP. While men overall presented less frequently with NTAP, they were more likely to subsequently experience a severe clinical course with a higher proportion of inpatient admissions and intensive care treatments, along with increased in-hospital mortality. Possible causes include both older age in men and differences in the most common diagnoses. For instance, women were more frequently diagnosed with conditions with typically uncomplicated disease course, such as cystitis (women: 5.1% versus men: 0.7% of all outpatient cases; p<0.001), while acute life-threatening diseases, such as pancreatitis, were more common among men (men: 5.6% versus women: 3.4% of all inpatient cases; p<0.001).

Symptom-descriptive diagnoses (“R diagnoses“) accounted for a large proportion of diagnoses coded in patients with NTAP who were treated on an outpatient basis, a finding consistent with corresponding data in the literature (1, 2). With regard to inpatient diagnoses, acute appendicitis, pancreatitis, and cholelithiasis were found to be among the „top 5“ most common diagnoses for inpatients with NTAP, both in our study and in the literature (1, 2).

Conclusion

Patients with NTAP were found to be younger and have a higher proportion of women compared to other patients in the ED. A greater proportion of men with NTAP were admitted for inpatient treatment and received intensive care, and they had a higher case fatality than women with NTAP. The most common outpatient diagnosis was abdominal and pelvic pain, the most common inpatient diagnosis was acute appendicitis. Sepsis was by far the leading cause of death. In everyday clinical practice, NTAP should not be underestimated and, for example, cases of sepsis should not be misdiagnosed as unexplained abdominal pain, but should be identified early. Initiatives aimed at establishing a consistent care structure, such as the “Abdominal Pain Unit” (5), can contribute to this goal (http://apu.charite.de).

Lukas Helbig, Martin Möckel, Antje Fischer-Rosinsky, Anna Slagman

Emergency and Acute Medicine (CVK, CCM), Charité, Universitätsmedizin Berlin, Berlin, Germany
(Helbig, Möckel, Fischer-Rosinsky, Slagman), [e-mail]

Conflict of interest statement
The authors declare no conflict of interest.

Manuscript received on 2 January 2023, revised version accepted on 28 June 2023

Translated from the original German by Ralf Thoene, MD

Cite this as:
Helbig L, Möckel M, Fischer-Rosinsky A, Slagman A: Non-traumatic abdominal pain—a retrospective analysis of secondary data from 448 689 cases treated in two emergency rooms in Berlin. Dtsch Arztebl Int 2023; 120: 613–4. DOI: 10.3238/arztebl.m2023.0163

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