Happy Hypoxia and Conscious Prone Position Ventilation

Ethiya N¹
Kalpana Rani U²
Nalini S³

¹Professor,
²Assistant Professor,
³Associate Professor,
Department of Physiology,
Government Theni Medical College,
Theni, Tamilnadu, India

Abstract
  • The traditional supine position suggested to patients lying in hospital beds has long been known to be detrimental to their underlying pulmonary function. Many asthmatic/COPD patients adopt leaning forward in sitting position than recline or supine positions. We were taught and we teach students to put patients with hypotension in trendlenberg position or to elevate foot end. Many of us are not aware that prone positioning improves both respiratory and cardiac functions significantly to the extent of saving lives. In the ongoing pandemic of COVID-19, 15% develop respiratory symptoms, 2-4% develop Hypocapnic Hypoxia, lethal Hypoxia without dyspnoea known as Happy Hypoxia/Silent Hypoxia, 6% develop Adult Respiratory Distress Syndrome (ARDS)and>3% die as even mechanical ventilation fail to rescue these patients. Understanding pathophysiology to pick up patients who may need medical careearly and finding treatment modalities that will reduce sudden deaths due to Happy Hypoxia, ICU care & Ventilator usage becomes paramount important and knowledge on these needs to be spread far &wide. Prone position ventilation has been proved to be advantageous to the extent of bringing down mortality. Conscious ventilation with high FiO2beingactive ventilation with respiratory muscles functioning leads to production of CO2 that maintains the sensitivity of carotid body chemo receptors to hypoxia. Pathophysiology of Happy Hypoxia &physiological factors that facilitate respiration and improve cardiac function when patient is nursed in prone position are discussed in this article.
  • Keywords: ARDS, COVID-19, Happy Hypoxia, Prone position ventilation