This is a prospective observational cohort study designed to evaluate the impact of alcohol consumption, psychoactive drug use, and prior administration of analgesics on the clinical evaluation process and surgical decision-making in patients with penetrating abdominal trauma.
The study will be conducted at two level I trauma centers in Cali, Colombia: one public university hospital and one private university hospital. Both institutions manage a high volume of trauma patients and apply standardized protocols based on serial physical examination for the evaluation of patients with penetrating abdominal trauma.
Patients older than 14 years who present with penetrating abdominal trauma and are hemodynamically stable will be evaluated according to routine institutional protocols, including serial abdominal physical examinations and selective use of diagnostic adjuncts such as focused abdominal sonography for trauma (FAST) or computed tomography, when clinically indicated. No additional diagnostic or therapeutic interventions will be performed as part of the study.
The exposure of interest is the presence of alcohol consumption, psychoactive substance use, or prior administration of analgesics before or during the initial clinical evaluation. These exposures will be identified through clinical assessment and medical record review and will be categorized according to predefined operational definitions.
The primary analytical focus is the interval between hospital admission and the decision for surgical intervention. Secondary analyses will explore associations between substance exposure and trauma severity, need for operative management, length of hospital stay, intensive care unit admission and length of stay, postoperative complications, and in-hospital mortality.
Data will be collected prospectively using standardized electronic case report forms. Data quality will be ensured through predefined range checks, consistency rules, and periodic review of entered data by the study investigators. Source data verification will be performed by comparing selected registry variables with information documented in the medical records.
Sample size was estimated to detect a clinically relevant difference in time to surgical decision between exposed and non-exposed patients, assuming an alpha level of 0.05, a statistical power of 80%, and an expected hazard ratio of 0.7. Based on the anticipated probability of requiring laparotomy of 0.68, a total of 247 events (laparotomies) were required, corresponding to 363 patients, to ensure an adequate number of events for time-to-event analysis.
Statistical analysis will include descriptive summaries of baseline characteristics, comparison of categorical variables using chi-square or Fisher's exact tests, and comparison of continuous variables using parametric or non-parametric methods as appropriate. Time-to-event analyses will be performed using Cox proportional hazards regression models, adjusting for relevant covariates such as age, sex, mechanism of injury, trauma severity, and type of substance exposure.
This study is observational and involves minimal risk to participants, as all evaluations and management decisions are part of standard clinical care. The results are expected to provide evidence regarding the reliability of serial physical examination in patients with penetrating abdominal trauma who present under the influence of alcohol, psychoactive substances, or analgesics, and may contribute to improving and standardizing trauma evaluation protocols across different clinical settings.
