Risk Factors for Developing Critical Illness Polyneuropathy at a Referral Medical Center in Lebanon: A Prospective Cohort Study.

Background Critical illness polyneuropathy (CIP) is a common neuromuscular complication in critically ill patients and is associated with increased morbidity, prolonged mechanical ventilation, and delayed recovery. This study aims to identify clinical factors associated with the development or progression of CIP in critically ill patients admitted to a tertiary care center in Lebanon. Methodology This prospective cohort study included 70 adult patients (≥18 years) admitted to the intensive care unit (ICU) at the American University of Beirut Medical Center. Baseline demographics, medical history, and clinical data were collected upon admission. Nerve conduction studies (NCS) were conducted on day zero and repeated on day seven of ICU stay. Hospital course details, new medications, and complications were recorded throughout the observation period. Categorical variables were analyzed using the chi-squared test, while continuous variables were compared using the Mann-Whitney U test. A p-value <0.05 was considered statistically significant. Results Of the 70 patients enrolled, 46 were excluded due to inability to complete the follow-up NCS, primarily because of ICU stays shorter than seven days. The final analysis included 24 patients, among whom nine (37.5%) developed new or progressive CIP by day seven. Among all clinical variables analyzed, only thyroid dysfunction showed a statistically significant association with CIP development (p = 0.026). Notably, 32% of patients with CIP had underlying hypothyroidism or hyperthyroidism. Other commonly suspected factors, including corticosteroid use, beta-blocker therapy, and sepsis, were not statistically significant in this cohort. Conclusions Thyroid dysfunction was significantly associated with the development of CIP in critically ill patients in this study. These findings suggest that thyroid status may play a previously underrecognized role in the pathogenesis of CIP and highlight the potential value of routine thyroid screening in ICU patients. Further research involving larger, multicenter cohorts is warranted to validate these results and investigate the mechanisms linking thyroid dysfunction to neuromuscular complications in critical illness.