Wrist restraints are for keeping the patient from pulling on intravenous lines and tubes. Such occurrences have disastrous effects, especially with lines that have been inserted into the chest wall. Bladder catheters have water-inflated balloons on the internal end to keep them from slipping out. When yanked out suddenly, they cause internal damage to the urinary sphincter. In men, the damage is much worse because the balloon is pulled internally through the length of the penis. So it is crucial to prevent this from occurring.
The downside is that wrist restraints can also cause injury when not applied properly or the wrong type of material is used. Current regulations forbid the use of items like gauze rolls or orthopedic stocking materials because they can cut off circulation and cause either nerve damage resulting in paralysis or gangrene resulting in amputation. The proper item is a wristband designed to maintain a comfortable space between the material and the skin and that remains in place with a Velcro fastener. The strap that restricts movement of the forearm ties to a loop that attaches to the wristband. Thus when patients pull on it (and they always do), they cannot cut off circulation to the hand. Most states have laws that prohibit the use of any other material.
Every hospital also has rules that require releasing the arms from restraints one at a time to allow full range of motion at least once every hour. Every nurse is required to maintain a restraint documentation record, and a doctor's order is required within one hour of the nurse's decision to apply such a measure. Hospitals also require that the doctors periodically renew and review such orders.