Title: Incidence and impact of chronic pain in discharged patients from an Intensive Care Unit 

Background and Goal of Study: Pain in the intensive care unit (ICU) patients is frequent, with an incidence of up to 50% in medical and surgical patients at rest and during common care procedures. Evidence demonstrates that adequate pain control is associated with improved patient outcomes in the ICU. This work aims to evaluate the acute pain during hospitalization and investigate the incidence and impact of chronic pain in patients after discharge.

Materials and Methods: Retrospective study of the incidence of pain during the ICU stay by evaluation of the Numeric Pain Scale (NPS) and the Behavioral Pain Scale (BPS). A questionnaire and telephone follow-up method was used to investigate the incidence of chronic pain, by the application of the Brief Pain Inventory (BPI) in this group of patients. 6 to 12 months post-discharged patients were included in the study. 

Results and Discussion: 72 patients were included in this study. During the ICU stay, the maximal pain score observed was 7 in both scales. A score of 0 (NPS) or 3 (BPS) was reported in 41.7% of the patients. Chronic pain was reported in 55.6% of all respondents. Shoulder pain was reported in 22%. Patients with persistent pain after ICU discharge had higher levels of pain assessed during hospitalization (p=0.002). Duration of mechanical ventilation of 5 or more days was associated with chronic pain referred to the shoulder joint (41.2% vs 16.4%; p=0.039). The mean pain score on the BPI questionnaire was 3.21.4. 42.5% of the patients referring chronic pain were taking analgesics (88.2% with paracetamol and/or metamizole), with a mean pain relief of 58.8%. None of these patients was being followed in a pain unit. The mean values of functional interference were 4.32.5 on general activity, 3.42.4 on mood, 3.23.1 on the ability to walk, 3.72.3 on normal work, 2.41.8 on relations with other people, 2.22.3 on sleep and 2.92.4 on enjoyment of life.

Conclusion(s): Chronic pain has a high incidence in survivors of critical illness after ICU discharge. The systematic assessment of pain and its control are essential as greater levels of acute pain are associated with higher incidence of chronic pain.

Incidence and impact of chronic pain in discharged patients from an intensive care unit