system
Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
user
A patient brought to the emergency room after a road traffic accident shows cyanosis. Which of the following is TRUE regarding in this patient?
assistant
The correct answer is  Cyanosis becomes apparent when the concentration of reduced hemoglobin in capillary blood exceeds 40 g/L (4 g/dL). Cyanosis is an extremely late sign of hypoxemia and may not occur at all if there has been extensive blood loss. Indeed, a patient has to have 5 grams of deoxygenated hemoglobin per 100 cc of blood for cyanosis to occur. Ref: Loscalzo J. (2012). Chapter 35. Hypoxia and Cyanosis. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.