Individualized Analgesia in the Intensive Care Unit With a New Pain Assessment Bundle and Protocolized Analgesia Adjustments

Individualized Analgesia in the Intensive Care Unit With a New Pain Assessment Bundle and Protocolized Analgesia Adjustments (INVISIBLE) - an Observational Single-Centre Study in Critically Ill Patients

Both severe pain and opioid therapy are associated with negative effects. The experience of pain is common in the intensive care unit, but it is highly individual and difficult to assess, as patients are often unable to communicate. This especially applies to patients who are mechanically ventilated. Behavioral assessment tools can help to identify pain in this population, but do not register overdose of opioid therapy. The AlgiScan® delivers the Pupillary Pain Index (PPI), an objective assessment of nociception level, which has been shown to be useful in small studies with respect to reduction of opioid dose without leading to more pain.

New institutional protocols for the assessment of pain include the behavioral pain assessment tool Zurich Observational Pain Assessment (ZOPA) and the PPI. This project aims to evaluate the impact of the new institutional protocols on opioid administration and occurrence of pain compared to a historical cohort by analyzing routinely collected data during mechanical ventilation (Part A). In a second part (Part B), promising biomarkers for detection of pain, subjective ratings by nurses and physicians and an additional behavioral pain scale will be evaluated using an observational study design. After screening and enrolment (day 1/visit 1), characteristics of pain will be assessed on 4 occasions during 2 days (day 2/visit 2, day 2/visit 3, day 3/visit 4, day 3/visit 5). On visit 2 and 4, biomarkers (alpha-amylase, cortisol) will be sampled.

Inclusion Criteria:

Part A

• Admission to the intensive care unit
• Adults (≥18 years) of all sex and gender
• Mechanical ventilation Part B
• Admission to the intensive care unit
• Adults (≥18 years) of all sex and gender
• mechanical ventilation
• Continuous opioid therapy
• Richmond Agitation Sedation Scale (RASS) ≤ -4
• Presumed duration of mechanical ventilation until the end of observations (until day 3)
• Established vascular access suitable for blood sampling independent of study inclusion (arterial line or central venous catheter)

Exclusion Criteria:

Part A

• None Part B
• Previous enrolment into the current investigation
• Tracheostomy
• Chronic opioid use
• Regional anaesthesia
• Implanted pacemaker device
• Allergy to silicone or ECG-electrodes
• Ophthalmologic disease (e.g. ocular trauma, glaucoma) or past eye surgery
• Fixed pupils
• Known or suspected neurologic disease (including hypoxic encephalopathy)
• Therapy with atropine or topical mydriatics in previous 24 hours or planned
• Therapy with systemic steroids in previous 24 hours or planned
• Therapy with neuromuscular blocking agents in previous 24 hours or planned
• Stomatitis
• Active oral or nasal bleeding