why does the tidal volume on the patient side sometimes higher than dialed in tidal volume on a/c ventilators?

Question

example set tidal volume 750 ml , and tidal volume on patient data on vent will read lower or higher

Answer 1

You should probably ask this question in Medicine instead of Physics.

Answer 2

Good question and interesting that you picked up on this technical point. Are you in the medical field? In general we have converted to low tidal volume ventilation as a lung protective strategy for all patients. However there are always exceptions to the rule, some exceptions may include: severe metabolic acidosis in which the tidal volume is increased to help blow off CO2 and improve acid-base status, usually we increase the respiratory rate first to help increase minute ventilation and blow off CO2 but if the patient is already breathing fast on their own then we assist by increasing the tidal volume. Another case may be for patients with COPD or asthma who have "air hunger", they may feel short of breath with small volumes. The actual amount of volume is not as important as its effect on the lung pressures. If the lung pressures can be maintained despite a higher volume then barotrauma is less likely. You can see if you can find the peak pressure number on the ventilator, it should be less than 30. Hope this helped, mechanical ventilation is a very complex topic. Post your dad's condition if you want so we can find an explanation for his specific condition. Hope he gets better.

Answer 3

What?