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 Presentation ＜#＞ICU-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 weakness＜#＞CNS: 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-AW＜#＞Critical Illness Myopathy (CIM): • Muscle dysfunctionEarly onset (within 48 hrs)Sensation intactproximal ＞ distal weakness ＜#＞Critical Illness Polyneuropathy (CIP): • Nerve involvementDistal ＞ proximal weakness, sensory deficits • Critical Illness Polyneuromyopathy (CIPNM): Combination of both Diagnosis • Medical Research Council Score (MRC-SS): • Score ＜ 48: ICU-AW • Score ＜ 36: severe ICU-AW • Handgrip dynamometry: ＜11 kg (men), ＜7 kg (women) • Electrophysiology: EMG/NCS to distinguish CIM vs CIP • Muscle ultrasound: bedside monitoring • MRI/CT/Muscle biopsy: rarely used due to practical limitation Risk Factors Modifiable: • Hyper/hypoglycemia • Electrolyte derangement • Parenteral nutrition • Immobility • Medications (steroids, NM blockers, sedatives, aminoglycosides) Non-modifiable: • Age, female sex, comorbidities • Severity of illness, prolonged ventilation • Sepsis, multi-organ failure  Management & Prevention • Prevention is key: • Early treatment of sepsis and inflammation • Glycemic control • Early enteral nutrition • Minimize sedation (A-F bundle) • Early mobilization and physical therapy • NMES (neuromuscular electrical stimulation): emerging therapy, needs more evidence Outcomes • Short-term: increased LOS, ventilation duration, mortality • Long-term: decreased function, discharge to rehab, prolonged recovery Final Takeaways • Prevention 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. (https://doi.org/10.1097/CCM.000000000...) 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. (https://pubmed.ncbi.nlm.nih.gov/28098628) 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. (https://pubmed.ncbi.nlm.nih.gov/30339549) 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. (https://pubmed.ncbi.nlm.nih.gov/34401939) 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. (https://pubmed.ncbi.nlm.nih.gov/32076765) 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. (https://pubmed.ncbi.nlm.nih.gov/26242743) Hermans G, Van den Berghe G. Critical Ca...