A predictor of early mortality in patients undergoing percutaneous endoscopic gastrostomy: systemic immune-inflammation index

Introduction: Percutaneous endoscopic gastrostomy (PEG) is a widely used procedure for patients with impaired oral intake due to various underlying conditions but with intact gastrointestinal tracts. Although generally considered safe and straightforward, PEG placement has been associated with a relatively high rate of early mortality. The mechanisms underlying this increased early mortality remain incompletely understood, but systemic inflammation is suspected to play a key role. Elevated inflammation markers, such as CRP and indices like the Systemic Immune-Inflammation Index (SII), have been linked to poor outcomes in PEG patients. However, it is still unclear whether PEG placement itself influences these inflammatory markers or whether high inflammation is primarily related to the underlying disease necessitating PEG. Clarifying the relationship between inflammation, PEG application, and early mortality is essential for better patient selection and management. Therefore, this study aimed to evaluate the association between pre-PEG inflammation status, as measured by SII, and early mortality following PEG placement.Methods: This prospective observational study included 96 patients aged 18 years and older who underwent PEG placement within 30 days prior to admission to the Palliative Care Clinic at Etlik City Hospital, Department of Internal Medicine, between February and June 2024. The study population consisted of patients with various underlying conditions necessitating PEG for enteral nutrition. The inclusion and exclusion criteria were clearly defined to establish a homogeneous cohort. Sample size was determined based on previous literature and power calculations to detect significant associations between inflammatory markers and mortality. Baseline laboratory values—including CRP, albumin, neutrophil, lymphocyte, and platelet counts—were collected from patient records prior to PEG placement. The Systemic Immune-Inflammation Index (SII) was calculated using the formula: platelet count × neutrophil count / lymphocyte count. The timing of laboratory assessments was standardized to within 48 hours before PEG. Patients’ treatments, including anti-inflammatory or immunosuppressive therapies, were documented as potential confounders affecting inflammatory markers. Patients were followed for 30 days post-PEG placement to assess early mortality. Statistical analyses were performed to evaluate the relationship between pre-PEG SII and mortality outcomes, adjusting for potential confounding factors including underlying diseases and treatments.Results: Of the 96 patients included in the study, 58 (60.4%) were female and 38 (39.6%) were male. CRP values ranged from 1 to 189.2 mg/L, with a mean of 58.18 ± 45.46 mg/L. Patients who died within 30 days post-PEG had significantly higher CRP levels compared to survivors (p = 0.031). Neutrophil counts ranged from 1,440 to 24,420/µL, with a mean of 6,913.24 ± 4,344.73/µL; deceased patients exhibited significantly elevated neutrophil counts (p = 0.001). Lymphocyte counts ranged between 120 and 3,400/µL, averaging 1,346.38 ± 729.30/µL; patients who died had significantly lower lymphocyte counts (p = 0.013). The SII values ranged from 107.70 to 12,920, with a mean of 1,766.32 ± 1,868.75; higher SII values were significantly associated with mortality (p = 0.001).Conclusion: Percutaneous endoscopic gastrostomy is a safe and effective method for providing enteral nutrition when applied under appropriate clinical conditions. Elevated pre-PEG inflammatory markers, specifically SII and CRP, are significantly associated with early mortality and can serve as useful predictors. Assessment of these parameters prior to PEG placement may assist clinicians in better selecting patients who are most likely to benefit from the procedure.