The Management of Chronic Hypoventilation: Mechanical Ventilation (1)
Negative pressure ventilators consist of the tank ventilator or “iron lung” and various modifications, the “raincoat” or “pneumowrap” ventilator, and the chest cuirass or “tortoise shell.” The tank ventilator applies intermittent negative pressure to the entire body below the neck and is the most efficient of the negative pressure ventilators. Capable of sustaining patients through bouts of acute respiratory failure, it can be used to support patients with virtually no ventilatory reserve. Unfortunately, it is bulky, heavy, and imposing, and patient acceptance is limited.
The raincoat ventilator consists of an impervious nylon jacket that is suspended over the chest and abdomen by a rigid plastic or metal chest piece and is attached to a negative pressure ventilator. It is vastly more portable than the tank ventilator, but placing weak or paralyzed patients into it can be taxing. In addition, patients must he supine within it and musculoskeletal back and shoulder pains are common. levitra super active plus
The cuirass ventilator consists of a rigid shell that is firmly placed on the anterior chest and abdomen and is attached to a negative pressure ventilator. Once it has been properly fitted, it is much easier to apply than either the pneumowrap or tank ventilator. However, because it applies negative pressure over a smaller surface area, it is less effective and should be used with caution in patients with minimal ventilatory reserve. Fitting can also be difficult, particularly in patients with chest wall deformities.