Occurrence and characteristics of pain after ICU discharge: A longitudinal study

Pain is a serious problem for intensive care unit (ICU) patients, but we are lacking data on pain at the hospital ward after ICU discharge.

To describe pain intensity, -interference with function and -location in patients up to 1 year after ICU discharge. To identify demographic and clinical variables and their association with worst pain intensity and pain interference.

A longitudinal descriptive secondary analysis of a randomized controlled trial on nurse-led follow-up consultations on post-traumatic stress and sense of coherence after ICU discharge.

Pain intensity, -interference, and -location were measured using Brief Pain Inventory at the hospital ward and 3, 6, and 12 months after ICU discharge. For associations, data were analysed using multivariate linear mixed models for repeated measures.

Of 523 included patients, 68% reported worst pain intensity score above 0 (no pain) at the ward. Estimated means for worst pain intensity and -interference (from 0 to 10) after ICU discharge were 5.5 [CI 4.6-6.5] and 4.5 [CI 3.7-5.3], and decreased to 3.8 [CI 2.8-4.8] (P ≤ .001) and 2.9 [CI 2.1-3.7] after 12 months (P ≤ .001). Most common pain locations were abdomen (43%), lower lumbar back (28%), and shoulder/forearm (22%). At 12 months, post-traumatic stress (PTS) symptoms ≥25 (scale 10-70), female gender, shorter ICU stay, and more traumatic ICU memories were significantly associated with higher worst pain intensity. PTS symptoms ≥25, female gender, more traumatic ICU memories, younger age, and not having an internal medical diagnosis were significantly associated with higher pain interference.

Early after ICU discharge pain was present in 68% of patients. Thereafter, pain intensity and -interference declined, but pain intensity was still at a moderate level at 12 months. Health professionals should be aware of patients' pain and identify potentially vulnerable patients.

Longitudinal assessment of factors associated with pain early after ICU discharge and the following year is a first step that could improve follow-up focus and contribute to reduced development of chronic pain.