Placing patients on ventilator support in the ICU setting can be life-saving. Most people, and even some physicians, are not aware of the signifi cant muscle problems that result from even 24 hours of mechanical ventilation in an Intensive Care Unit (ICU). When patients are on mechanical ventilation they are generally sedated and, as a consequence, are not moving.

Studies have shown that this inactivity can result in signifi cant muscle weakness and functional loss. Recently, more study and understanding has been focused on the affect mechanical ventilation has on the function of the diaphragm. The contraction of the diaphragm is the main mechanism that causes us to breath. It has been shown that weakness can develop in the diaphragm after only 24 hours of ventilator support. The weakness and sensitivity to inactivity of the diaphragm is much more severe than the other muscles that move our arms and legs. The reason for this is that the diaphragm is contracting continuously in the normal state. When on ventilator support the diaphragm is not contracting and is thought to weaken much more rapidly than other muscles. When patients seem well enough to have their ventilator support removed they are weaned from this support by allowing them to breath on their own before their breathing tube is removed. Diaphragmatic weakness may cause these weaning maneuvers to fail or it may delay the patient’s ability to breath on their own. This delay prolongs the bedrest and inactivity and further weakens arm and leg muscles.