105. ICU Acquired Weakness

Today we’re talking about a topic that is relevant for all critical care physicians but under-examined: ICU Acquired Weakness. We are joined by two excellent guests to walk through a case and discuss the diagnosis, pathophysiology, prevention, and treatment of ICU Acquired Weakness. Check out our associated infographics and key learning points below. Meet Our Guests Jim Devanney is a Physiatrist who just completed a neurocritical care fellowship at BIDMC. He is transitioning to a clinical associate position at University Health Network – University of Toronto where he will be working as a PM&R consultant within the ICU. Kalaila Pais is a third year internal medicine resident at BIDMC, interested in pulmonary and critical care and medical education and is returning for her third Pulm PEEPs episode. Key Learning Points Definition & Clinical PresentationICU-AW refers to new-onset, generalized muscle weakness that arises during critical illness, not explained by other causes.It typically presents as:Symmetric, proximal > distal weaknessRespiratory muscle involvementPreserved cranial nerve functionNo sensory deficits in myopathy (sensory loss points toward neuropathy)Differential Diagnosis Using Neuroanatomical ApproachAn anatomical approach (central → peripheral) helps localize the etiology weaknessCNS: trauma, stroke, encephalitis, seizuresAnterior horn cells: viral myelitis, motor neuron diseasePeripheral nerves: Guillain-Barré, vasculitis, critical illness polyneuropathy (CIP)Neuromuscular junction: myasthenia gravis, botulism, Lamber EatonMuscle: rhabdomyolysis, inflammatory or drug-induced myopathies, critical illness myopathy (CIM)Subtypes of ICU-AWCritical Illness Myopathy (CIM):Muscle dysfunctionEarly onset (within 48 hrs)Sensation intactproximal > distal weaknessCritical Illness Polyneuropathy (CIP):Nerve involvementDistal > proximal weakness, sensory deficits Critical Illness Polyneuromyopathy (CIPNM): Combination of bothDiagnosisMedical Research Council Score (MRC-SS):Score < 48: ICU-AWScore < 36: severe ICU-AWHandgrip dynamometry: <11 kg (men), <7 kg (women)Electrophysiology: EMG/NCS to distinguish CIM vs CIPMuscle ultrasound: bedside monitoringMRI/CT/Muscle biopsy: rarely used due to practical limitationRisk FactorsModifiable:Hyper/hypoglycemiaElectrolyte derangementParenteral nutritionImmobilityMedications (steroids, NM blockers, sedatives, aminoglycosides)Non-modifiable:Age, female sex, comorbiditiesSeverity of illness, prolonged ventilationSepsis, multi-organ failure Management & PreventionPrevention is key:Early treatment of sepsis and inflammationGlycemic controlEarly enteral nutritionMinimize sedation (A-F bundle)Early mobilization and physical therapyNMES (neuromuscular electrical stimulation): emerging therapy, needs more evidenceOutcomesShort-term: increased LOS, ventilation duration, mortalityLong-term: decreased function, discharge to rehab, prolonged recoveryFinal TakeawaysPrevention is crucial — start interventions early.Systematic approach to ICU weakness helps rule out dangerous mimics.ICU-AW is common but often under-recognized — awareness and early rehab can significantly impact recovery. Infographics References and Further Reading Clinical Practice Guidelines for the Prevention and Management of Pain, Agitation/­Sedation, Delirium, Immobility, and Sleep Disruption in Adult Patients in the ICU. Devlin JW, Skrobik Y, Gélinas C, et al. Critical Care Medicine. 2018;46(9):e825-e873. doi:10.1097/CCM.0000000000003299. The ABCDEF Bundle: Science and Philosophy of How ICU Liberation Serves Patients and Families. Ely EW. Critical Care Medicine. 2017;45(2):321-330. doi:10.1097/CCM.0000000000002175. Caring for Critically Ill Patients With the ABCDEF Bundle: Results of the ICU Liberation Collaborative in Over 15,000 Adults. Pun BT, Balas MC, Barnes-Daly MA, et al. Critical Care Medicine. 2019;47(1):3-14. doi:10.1097/CCM.0000000000003482. Delirium in Critical Illness: Clinical Manifestations, Outcomes, and Management. Stollings JL, Kotfis K, Chanques G, et al. Intensive Care Medicine. 2021;47(10):1089-1103. doi:10.1007/s00134-021-06503-1. ICU-acquired Weakness. Vanhorebeek I, Latronico N, Van den Berghe G. Intensive Care Medicine. 2020;46(4):637-653. doi:10.1007/s00134-020-05944-4. Clinical Review: Intensive Care Unit Acquired Weakness. Hermans G, Van den Berghe G. Critical Care (London, England). 2015;19:274. doi:10.1186/s13054-015-0993-7. Best Practices for Conducting Interprofessional Team Rounds to Facilitate Performance of the ICU Liberation (ABCDEF) Bundle. Stollings JL, Devlin JW, Lin JC, et al. Critical Care Medicine. 2020;48(4):562-570. doi:10.1097/CCM.0000000000004197. ABCDE and ABCDEF Care Bundles: A Systematic Review of the Implementation Process in Intensive Care Units. Moraes FDS, Marengo LL, Moura MDG, et al. Medicine. 2022;101(25):e29499. doi:10.1097/MD.0000000000029499.