A 45 year old man who is a known asthmatic came to the ER with acute exacerbation. He was dyspneic . His heart rate was 120 per minute and blood pressure was 160/90 mmHg. A blood gas analysis revealed PaO2 of 55mmHg and PaCO2 of 65 mmHg. Which of the following is an indication for endotracheal intubation?
  1. Age
  2. Long history of asthma
  3. Tachycardia
  4. Hypoxia

Answer: The answer is (d). Usual indications of endotracheal intubation include impaired gas exchange, rapid onset respiratory failure, refractory to treatment and respiratory muscle fatigue. Parameters which guide intubation are hypoxia, respiratory rate >35, hypercarbia and absent gag or cough reflex.