Opioid drugs (e.g., Morphine, Fentanyl and Remifentanil) are widely used for the treatment of pain (e.g., perioperative and cancer pain) and systemic analgesia, and to also maintain patients adapted to mechanical ventilation in the ICU. They have side effects, even at therapeutic dose, that could affect gastrointestinal (GI) motility, such as vomiting (i.e., stimulation of the vomiting centre) and constipation (i.e., decreased gastric emptying and gut motility), which may negatively influence nutrition therapy in critically ill patients [1-4]. Opioid antagonists (e.g., Naloxone) may attenuate the effect on GI motility of opioids. Their oral administration (e.g., Methylnaltrexone) may be last-line medication for patients with opioid-induced constipation in the ICU (i.e., insufficient response to laxative therapy) [3, 4].
Feasibility/Equipment: The appropriate dosage (i.e., at the lowest effective dose) and type of opioids (i.e., less lasting effect) for the management of analgesia need should be clinically evaluated by all members of the healthcare team to assure patient comfort and minimize their side effects [5]. Clinical experience and expertise in the management of opioids is paramount for this purpose. The administration of opioid antagonist may be evaluated by the medical staff who has to balance the potential benefit (i.e., treatment of opioid side effects) together with the potential for the reversal of analgesia.
Scoring information: The use of scales, such as Behavioral Pain Scale for Pain Assessment in Intubated Patients (Score ≤3 indicates no pain) and Critical Care Pain Observation Tool (score of ≤ 2 indicates no pain), has shown validity and reliability for monitoring pain among critically ill adults unable to self-report pain and in whom behaviors are observable [5].
Cost: Costs of measurement are low since this should be part of current clinical assessment.
Evidence: Inappropriate use of opioids (i.e., higher dosage and longer use) is strongly associated with worst outcomes, such as higher rates of GI complications that may negatively affect nutrition therapy [1-5]. The use of opioid antagonist seems intuitively beneficial, but studies showed unclear results, especially in terms of improvement of GI motility, and their use may be individualized [3, 4].
Accuracy / measurement properties: Administration of high dose of opioids in conjunction with sedatives have also been associated with worst hospital survival (Hazard radio from 1.02 to 1.20) [5]. Opioid-induced constipation may occur in up to 81% of critically ill patients [4]. Contemporary trials have found no benefit (e.g., reduced rescue-free laxation or gastric residual volume) with opioid antagonist use (e.g., methylnaltrexone) [3, 4].
References
1. Stein C: New concepts in opioid analgesia. Expert Opin Investig Drugs 2018, 27(10):765-775.
2. Murnion BP, Demirkol A: Opioid use disorder in anaesthesia and intensive care: Prevention, diagnosis and management. Anaesth Intensive Care 2022, 50(1-2):95-107.
3. Yan Y, Chen Y, Zhang X: The effect of opioids on gastrointestinal function in the ICU. Crit Care 2021, 25(1):370.
4. Chapple LA, Deane A. From dysmotility to virulent pathogens: implications of opioid use in the ICU. Curr Opin Crit Care 2018, 24(2):118-123.5.
5. Devlin JW, Skrobik Y, Gélinas C, Needham DM, Slooter AJC, Pandharipande PP, Watson PL, et al: Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU. Crit Care Med 2018, 46(9):e825-e873.