인공호흡기 이탈을 위한 원인 기반 접근법: 자발호흡 시도를 넘어

Liberation from mechanical ventilation has long been approached as a protocolized problem in the intensive care unit (ICU), with spontaneous breathing trial (SBT)-based frameworks refined over decades by pulmonology and critical care. This approach succeeds in patients with parenchymal lung disease, but a substantial subset of ventilator-dependent patients fails repeated weaning attempts because of pathophysiologic processes that ICU-based protocols are not designed to address. This narrative review proposes a complementary, etiology-based framework that classifies ventilator-dependent patients into four categories: (1) pulmonary, in which gas exchange and lung mechanics dominate and SBT protocols apply; (2) muscle, in which respiratory muscle weakness — including ICU-acquired weakness, ventilator-induced diaphragm dysfunction, and neuromuscular disease — necessitates muscle support, with non-invasive ventilation enabling extubation without tracheostomy in selected patients; (3) brain, in which central respiratory drive impairment requires recognition of demand-modifying factors and acceptance of a longer recovery timeline given brainstem plasticity; and (4) aspiration, which overlaps with the other categories but warrants separate consideration because airway protection failure — not respiratory dysfunction — drives ventilator dependence. For three of these four etiologies, weaning need not be completed within the ICU and may proceed in post-acute settings where rehabilitation medicine provides structured intervention. The author argues that weaning failure in many patients reflects a diagnostic mismatch rather than protocol inadequacy, and that recognition of this distinction enables more accurate venue selection and earlier referral. The framework is offered not as a replacement for established protocols, but as a complementary lens for patients in whom standard approaches stall.