Nitsure Mohana, Sarangi Bhakti, Shankar Guruprasad H, Reddy Venkat S, Walimbe Ajay, Sharma Varsha, Prayag Shirish
Department of Pediatrics, Bharati Vidyapeeth Medical College and Hospital, Pune, Maharashtra, India.
Critical Care Medicine, Prayag Hospital, Shree Medical Foundation, Pune, Maharashtra, India.
Indian J Crit Care Med. 2020 Oct;24(10):967-970. doi: 10.5005/jp-journals-10071-23547.
Coronavirus disease-2019 (COVID-19) causes severe hypoxemia which fulfills the criteria of acute respiratory distress syndrome (ARDS) but is not accompanied by typical features of the syndrome. The combination of factors including low P/F ratios, high A-a gradient, relatively preserved lung mechanics, and normal pulmonary pressures may imply a process occurring on the vascular side of the alveolar-capillary unit. The scant but rapidly evolving data available on the pathophysiology are seemingly conflicting, indicating the relative dominance of intrapulmonary shunting or dead space in different studies. In this hypothesis paper, we attempt to gather and explain these observations within a unified conceptual framework by invoking the relative contributions of microvascular thrombosis, along with two proposed vascular mechanisms of capillary flow redistribution and flow through intrapulmonary arteriovenous anastomoses (IPAVA). Nitsure M, Sarangi B, Shankar GH, Reddy VS, Walimbe A, Sharma V, Mechanisms of Hypoxia in COVID-19 Patients: A Pathophysiologic Reflection. Indian J Crit Care Med 2020;24(10):967-970.
2019冠状病毒病（COVID-19）可导致严重低氧血症，符合急性呼吸窘迫综合征（ARDS）的标准，但不伴有该综合征的典型特征。包括低P/F比值、高肺泡-动脉血氧分压差、相对保留的肺力学以及正常肺压力等多种因素的组合，可能意味着在肺泡-毛细血管单元的血管侧发生了某种过程。关于病理生理学的现有数据虽少但迅速发展，似乎相互矛盾，表明在不同研究中肺内分流或无效腔占相对主导地位。在这篇假说论文中，我们试图通过引入微血管血栓形成的相对作用，以及提出的两种血管机制，即毛细血管血流重新分布和通过肺内动静脉吻合支（IPAVA）的血流，在一个统一的概念框架内收集并解释这些观察结果。Nitsure M、Sarangi B、Shankar GH、Reddy VS、Walimbe A、Sharma V，《COVID-19患者缺氧的机制：病理生理学思考》。《印度危重症医学杂志》2020年；24（10）：967 - 970。
