A 60 year old woman with acute exacerbation of Chronic bronchitis is intubated and put on mechanical ventilation for her respiratory failure. Which of the following modes of ventilation is most appropriate to begin with?
  1. Assist control ventilation (ACV)
  2. Intermittent mandatory ventilation (IMV)
  3. Pressure support ventilation (PSV)
  4. Synchronous intermittent mandatory ventilation (SIMV)

Answer: The answer is (a). Assist control is the initial mode to be used in most patients with respiratory failure. The states of reduced lung compliance are contra indications to the use of PSV. IMV and SIMV are good options when weaning is started but not a good starting option.