RESUMEN
There is a high burden of critical illness in low-income countries (LICs), adding pressure to already strained health systems. Over the next decade, the need for critical care is expected to grow due to ageing populations with increasing medical complexity; limited access to primary care; climate change; natural disasters; and conflict. In 2019, the 72nd World Health Assembly emphasised that an essential part of universal health coverage is improved access to effective emergency and critical care and to "ensure the timely and effective delivery of life-saving health care services to those in need". In this narrative review, we examine critical care capacity building in LICs from a health systems perspective. We conducted a systematic literature search, using the World Heath Organisation (WHO) health systems framework to structure findings within six core components or "building blocks": (1) service delivery; (2) health workforce; (3) health information systems; (4) access to essential medicines and equipment; (5) financing; and (6) leadership and governance. We provide recommendations using this framework, derived from the literature identified in our review. These recommendations are useful for policy makers, health service researchers and healthcare workers to inform critical care capacity building in low-resource settings.