Now that you’ve gained a few extra pounds after holiday meals, or let’s say you gained 50lbs, should that change your ventilator settings if you get intubated?

 

Answer: No.

In order to avoid lung injury,  critical care literature suggests using low volume ventilation (~ 6 cc/kg of predicted body weight, aka IDEAL BODY WEIGHT). Ideal body weight depends on gender and height.

Ideal body weight for men in kgs = 50 + 2.3 (height (in) – 60).

Ideal body weight for women in kgs = 45.5 + 2.3 (height (in) – 60).

Therefore, Santa Claus would need the same tidal volume as an anorexic man of his height; this is because the actual lung parenchyma does not increase in size as the person gains more weight. Using height and gender allows for a more accurate representation of their lung volume and better ventilation strategies.

This is particularly important when managing ill patients with ARDS (acute respiratory distress syndrome). Open the below link to get an idea of what the ARDS protocol entails. It’s not meant to be memorized, as the chart can be followed in a step-wise fashion, but the basic idea is to nourish inflammed lung tissue with low tidal volumes (calculated based on ideal body weight) and pressures. Even with this protocol, however, mortality for ARDS is still very high, hovering around 40%. http://www.ardsnet.org/files/ventilator_protocol_2008-07.pdf

References

http://www.ardsnet.org/

http://www.medscape.com/viewarticle/741166_3