The Post-ICU Pain Study

Recruiting

• Conditions: Chronic Pain; Post Intensive Care Unit Syndrome; Pain Disorder; Quality of Life

• Registration Number: NCT07180407
• Lead Sponsor: Zealand University Hospital

Brief Summary

BACKGROUND: ICU survivors may experience serious psychological, physical and cognitive impairments following ICU admission, collectively termed Post Intensive Care Syndrome (PICS). Persistent pain is an underrecognized component of PICS. Previous research has shown that persistent pain is a profound clinical challenge in ICU survivors, however, research demonstrates conflicting results. Furthermore, no studies have examined the prevalence of persistent pain in ICU survivors in a contemporary Danish ICU setting.

OBJECTIVES: We aim to examine the clinical trajectory, risk factors, and pathophysiology of persistent pain in ICU survivors in Denmark.

DESIGN AND SAMPLE SIZE: The study is designed as a multicenter, prospective, inception cohort study with clinical follow-up. Based on the pre-study sample size calculation, 800 patients will be included. Patients will be contacted by telephone 90 days and 180 days after ICU discharge, and a series of questionnaires regarding pain, sleep quality, affective state and quality of life will be completed. A subgroup of patients will undergo a detailed clinical examination including quantitative sensory testing between 180-365 days after ICU discharge.

POPULATION: Patients will be recruited from 4 Danish ICU departments. Inclusion criteria include adult patients (18 years of age), acute admission to the ICU, and an ICU admission of a minimum of 48 hours.

OUTCOMES: The primary outcome is the prevalence of pain assessed by the Brief Pain Inventory (BPI) at 90 and 180 days after ICU discharge. Secondary outcomes include additional detailed descriptions of pain and daily activity, sleep quality, affective state, quality of life, treatment- and patient-related risk factors, and biomarkers associated with development of persistent pain.

Substudies:

\- QST substudy: 80 participants (40 with pain and 40 without pain) recruited from the main cohort will undergo Quantative Somatosensory Testing (QST). The objectives are first, to delineate somatosensory profiles of ICU survivors with and without pain, and second, to examine the presence of neuropathic pain in ICU survivors.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2025-07-15
• Status Verified: 2025-09
• Study First Submitted QC: 2025-09-11
• Study First Posted: 2025-09-18
• Study Start: 2025-09-23
• Last Update Submitted: 2025-09-29
• Last Update Posted: 2025-09-30
• Primary Completion: 2027-01
• Study Completion: 2027-06-01

Recruitment & Eligibility

• Status: RECRUITING
• Sex: All
• Target Recruitment: 800

Inclusion Criteria

• Adult ICU patients ≥18 years of age
• Acute admission to the ICU
• ICU length of stay of at least 48 hours

Exclusion Criteria

• Patients transferred from a non-participating ICU
• Patients with pre-planned admission to the ICU e.g., following elective surgery
• Patients unable to complete questionnaires, including those who are unable to understand or speak Danish, or patients with severe cognitive deficits.

Study & Design

• Study Type: OBSERVATIONAL
• Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
Prevalence of pain	180 day follow-up	Patients are defined as having pain if they answer "yes" to question number 1 in the Brief Pain Inventory - Short Form

Secondary Outcome Measures

Name	Time	Method
Brief Pain Inventory - Short Form (BPI-SF)	At follow-up at 90 and 180 days	Additional components of the Brief Pain Invenstory Short Form
Incidence of new-onset persistent pain after ICU discharge	at 90 and 180 days follow-up	Definition of new-onset persistent pain: Individuals presenting with pain according to Brief Pain Inventory Short Form at 90 AND 180 days follow-up AND not suffering from persistent pain/using pain medication regularly before ICU admission, as reported by the individual.
Quality of life measured by EuroQol-5-domain 5-level (EQ-5D-5L)	at 90 and 180 days	The EQ-5D-5L comprises 5 components (mobility, self-care, usual activity, pain/discomfort, and anxiety/depression) which can be rated at 5 levels. Furthermore, a Visual Analog Scale (VAS) documents self-rated health
The Single Item Sleep Quality Scale (SQS)	at 90 and 180 days	The respondent is asked to rate the overall quality of sleep over a 7-day recall period on a VAS. Respondents are instructed to consider the following components before answering the questionnaire: hours of sleep, night wakings, how easily they fall asleep, how often they wake earlier then needed, and how refreshed they feel when waking. Sleep quality is scored as follows: 0 = terrible, 1-3 = poor, 4-6 = fair, 7-9 = good, and 10 = excellent
Hospital Anxiety and Depression Scale (HADS)	at 90 and 180 days	It comprises seven questions regarding anxiety and seven questions regarding depressive symptoms. Anxiety and depression are scored separately with recommended cut-off values of 8-10 for possible presence of a mood disorder and \>11 for probable presence of a mood disorder
Self-Reported Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS)	90 and 180 days	Only patients answering "yes" to the Brief Pain Inventory Short Form, question number 1, will be asked to fill out the S-LANSS. The tool was created as a clinical tool to identify pain primarily of neuropathic origin, allowing for the differentiation between neuropathic pain and nociceptive pain. It contains 7 items assessing pain quality, sensory changes and specific symptoms commonly associated with neuropathic pain. A score above 12 suggests neuropathic pain
30-day mortality	30 days
90-day mortality	90 days
180 days mortality	180 days

Trial Locations

Locations (2)

Aalborg University Hospital; 🇩🇰 Aalborg, Denmark

Zealand University Hospital; 🇩🇰 Roskilde, Denmark