Experience in iliopsoas abscess treatment at a multi-specialty emergency inpatient care facility: A cohort retrospective study

Background. Iliopsoas abscess constitutes a rare pathology, and few studies on this topic are available in Russia. The literature describes only single observations, thus limiting statistical data analysis. Iliopsoas abscess mortality amounts to 12–15% and shows no signs of decreasing. The diagnosis is made using radiological imaging methods together with clinical and laboratory data to detect the signs of an inflammatory response and assess organ dysfunction and the severity of the condition. Treatment includes antibiotic therapy, abscess drainage, sepsis therapy, and correction of organ dysfunction. However, no uniform clinical guidelines for diagnosis and treatment are available. An analysis of available data on this pathology and study of factors affecting disease progression and prognosis will help to identify ways to improve treatment efficacy in the future. Objective. To conduct a retrospective analysis of the composition of iliopsoas abscess patients admitted to a multi-specialty inpatient care facility over an eight-year period, as well as to assess the results of diagnosis and treatment in this category of patients. Methods. A cohort retrospective study was conducted at the Saint-Petersburg I. I. Dzhanelidze Research Institute of Emergency Medicine; the study analyzed the medical records of 116 iliopsoas abscess patients hospitalized from January 01, 2015 to December 31, 2022. The main study parameters included iliopsoas abscess frequency and the composition of iliopsoas abscess patients, as well as their distribution by sex, age, presence of a background disease, etiology, and initial severity of the condition. The diagnostic significance of individual clinical symptoms, laboratory parameters, and imaging methods in iliopsoas abscess patients was assessed. The main study outcome was the identification of factors affecting the disease prognosis under the assumption that iliopsoas abscess mortality is largely affected such factors as individual reactivity and the presence of comorbid conditions. Additionally, the overall rate of postoperative complications was determined. Statistical analysis was performed using jamovi software, ver. 2.4.8.0 (Intel, USA). The effect of individual factors in nominal data comparisons was evaluated using Pearson’s χ 2 test; the odds ratio was used as a quantitative measure of effect size, and 95% confidence interval limits were calculated. Differences between groups were considered to be statistically significant at p < 0.05. Results. The median age was 59.5 (45–69) years. The patients included 65 (56.0%) males and 51 (44.0%) females. Primary iliopsoas abscess was diagnosed in 15 (12.9%) patients; secondary, in 101 (87.1%) patients. In the present study, iliopsoas abscesses were most commonly caused (58.6%, 68/116) by suppurative spinal infections. A typical clinical picture of psoas abscess was noted only in 27.6% (32/116) of patients. The disease was accompanied by systemic inflammatory response syndrome in 63.8% (74/116) of patients, severe sepsis in 43.1% (50/116) of patients, and septic shock in 2.6% (3/116) of patients. Most commonly, spiral computed tomography (69.8%, 81/116) was used as the abscess imaging method to establish the diagnosis. In 61.3% (54/88 positive cultures) of cases, Staphylococcus aureus was responsible for the infection, with MRSA ( methicillin-resistant Staphylococcus aureus ) accounting for 9.3% (5/54). The second most common causes of infection were Klebsiella pneumoniae and Escherichia coli . In primary and osteogenic abscesses, Gram-positive flora was isolated in 70.9% (56/79) of cases. In intestinal abscesses, gram-negative flora was observed in 83.3% (5/6) of cases; polymicrobial flora, in 50% (3/6) of cases. All iliopsoas abscess patients received antibiotic therapy and underwent abscess drainage. In 64.8% (57/88) of cases, the empiric antibacterial therapy matched the culture reports. Open surgery was performed in 93.1% (108/116) of cases and minimally invasive ultrasound-guided drainage was indicated in the remaining cases. A fatal outcome occurred in 14.7% (17/116) of patients. Statistically significant factors affecting a fatal outcome included concomitant diseases of the central nervous, cardiovascular, and respiratory systems; the presence of severe sepsis, multiple infection foci, acute protein deficiency, thrombocytopenia, and a severe initial condition. Conclusion. Iliopsoas abscess is difficult to diagnose. Its treatment requires a multidisciplinary approach, the identification and debridement of all foci of infection, monitoring and correction of organ dysfunction and protein deficiency, and treatment of the concomitant pathology. Charlson Comorbidity Index, SOFA (Sequential Organ Failure Assessment Score), APACHE II (Acute Physiology and Chronic Health Evaluation II), SAPS (original Simplified Acute Physiology Score), and C-reactive protein levels can be used to assess the mortality risk.