Question

6) In A/C mode, explain what happens with the tidal volume?

7) In Simv mode; explain what happens with the tidal volume with non-machine initiated breaths.

Answer 1

Assist -control mode is one of the most common method of mechanical ventilation in the intensive care unit. Ac ventilation is a volume cycled mode of ventilation. It works by setting a fixed tidal volume that the ventilator will deliver at set intervals of time or when the patient initiates a breath.

Tidal volume (Symbol VT or TV) is the lung volume representing the normal volume of air displaced between normal inhalation and exhalation when extra effort is not applied. In a healthy, young humsn adult, tidal volume is approximately 500mL per inspiration or 7mL /kg of body mass.

The SIMV mode, the patient is allowed to tak additional breaths in between the mechanical breaths. The patient's own breaths are called 'spontaneous breaths'. The size of these breaths may be large or small, depending upon the patient's abiltiy.