What complication is most closely associated with prolonged bed rest in critically ill patients?

Prolonged bed rest in critically ill patients is primarily associated with the development of deep vein thrombosis (DVT). This is due to several factors that contribute to venous stasis, which is a significant risk factor for DVT. When patients are immobilized for an extended period, the normal blood flow in the legs can be disrupted. Decreased mobility can lead to increased venous pressure and sluggish circulation, promoting the formation of blood clots within the deep veins.

In critically ill patients, other factors such as dehydration, hypercoagulable states related to inflammation, and potentially the use of certain medications can further increase the risk of DVT. The consequences of DVT can be severe, leading to more significant complications like pulmonary embolism if a clot dislodges and travels to the lungs, but DVT itself typically precedes this outcome and is more directly linked to immobility.

While other complications of prolonged bed rest, such as pressure ulcers, are significant, they are not as directly related to the physiological changes in the venous system caused by inactivity as DVT is. Gastrointestinal bleeding can occur in critically ill patients due to stress-related mucosal disease but is not primarily a result of immobility, and pulmonary embolism