PERSISTENT OPIOID USE AFTER INTENSIVE CARE ADMISSION: A 10-YEAR OBSERVATIONAL POPULATION-BASED COHORT STUDY IN A NORTHERN ITALIAN HOSPITAL

V. Damico | PhD, University of Milano-Bicocca, School of Nursing, ASST Lecco

INTRODUCTION
Opioid abuse has become a serious public health problem. Patients admitted to intensive care units are usually exposed to opioids, but the incidence and effects of chronic opioid use are unknown.
AIM
The primary objective of this study is to describe opioid use after admission to an intensive care unit. The secondary objectives are i) to identify factors associated with chronic opioid use and ii) to analyze the risk of death. This cohort study included all patients transferred to the intensive care unit of the A. Manzoni Hospital in Lecco between 2015 and 2025. Patients were interviewed by telephone 1 and 2 years after discharge from the intensive care unit.
RESULTS
Among the 1,624 patients included in the final study cohort, 171 (10.5%) developed persistent opioid use after ICU care. In the multivariable logistic regression analysis, determinants associated with higher odds of chronic opioid use included female sex, psychiatric and somatic comorbid conditions, substance dependence, preadmission opioid usage, and critical care stay for 3–7 days. In contrast, high age, high income and education, ICU stay for less than 7 days, were all associated with lower odds of persistent opioid usage. The adjusted hazard ratio for mortality between 12 and 24 months after hospitalization among subjects with persistent opioid use was 2.4 (95% CI 1.6–2.7; P < 0.001). During the 12-24 month follow-up after ICU admission, 103 patients died, of whom 29 (28.2%) were persistent opioid users. In Cox proportional hazards regression analysis (unadjusted), persistent opioid use was associated with higher mortality, a hazard ratio (HR) of 2.5 (95% CI 1.8–2.9; P < 0.001). After adjusting for covariates (age, sex, comorbid psychiatric and somatic conditions, substance dependence, and length of ICU stay, the association remained significant, HR of 2.1 (95% CI, 1.6–2.9; P < 0.001). Even among opioid-naïve patients, increased mortality was associated with persistent opioid use, adjusted HR of 2.1 (95% CI). 1.6-2.8; P < 0.001). Specific procedures, including spinal surgery (odds ratio, 2.21; 95% CI, 1.04-4.56) and arthroplasty (odds ratio, 1.98; 95% CI, 1.48-2.12), and patient characteristics, such as previous opioid use that was discontinued before surgery (OR, 2.01; 95% CI, 1.13-2.87) and the frequency of previously filled opioid prescriptions (OR, 9.12; 95% CI, 5.51-13.56), were associated with new persistent opioid use within 24 months of ICU discharge.
CONCLUSIONS
Mean opioid consumption increased one year after admission to ICU care even though no evidence supports long-term use of opioids. For opioid naïve patients, opioid use increased and without decline two years after ICU care. Chronic opioid users had an increased risk of death both in the total cohort as well as in the subgroup of opioid naïve patients.