Treatment outcomes and associated factors for patients with empyema thoracis managed at Mulago national referral hospital: a retrospective cohort study

Abstract

Background: Worldwide, the treatment outcomes of empyema thoracis patients remain unacceptably poor despite advances in management techniques. Recent data from the Western population indicate rising incidence and worsening outcomes of empyema thoracis patients. However, published data on empyema thoracis outcomes in Uganda are scarce.

Objective: To evaluate the treatment outcomes and associated factors for patients with empyema thoracis managed at Mulago National Referral Hospital (MNRH), Uganda.

Methodology: A retrospective review of file records of all patients with the diagnosis of empyema thoracis managed at MNRH from January 2017 to December 2021 was carried out. Information on patients’ sociodemographic, comorbidities, clinical parameters at admission, management, and outcomes were evaluated and summarized. A Poisson regression model with a robust standard error was used to identify independent factors for in-hospital mortality of empyema thoracis patients. All analyses weree2-sided (p<0.05). Results were reported in relative risks with 95% confidence.

Results: A total of 200 empyema thoracis cases were evaluated. Males were 123 (61.5%), females; 77 cases (38.5%). Majority of the cases, 80.5% (161 cases) were complicated parapneumonic effusions. We found the in-hospital mortality rate to be 10.5% (21 cases), and re-intervention was required in 33.5% (67 cases). Increasing age (RR=1.02 (1.01 – 1.04) p=0.009) and underlying etiology (RR=6.58 (2.50 – 17.18), p<0.0001) were independently associated with in-hospital mortality while delayed empyema drainage (RR=2.19 (1.24- 3.86), p=0.007) and etiology other than parapneumonic effusion (RR=2.23 (1.27 – 3.92), p=0.005) increased the likelihood of the need for re-intervention in empyema management.

Conclusion: In-hospital mortality (10.5%) and reintervention rate (33.5%) for empyema thoracis are high in MNRH. Age and the underlying empyema etiology influence mortality outcome while the re- intervention rate is influenced by the timing of drainage of the empyema and the underlying etiology.