Studies have been done on the antipsychotic drug, "haloperidol" to see if it prolongs the heart's QT interval.
What is a QT interval? What does it do? How is it measured? Does the heart rate have to be slow and regular? Where are my calipers?
Nurses aren't supposed to give haloperidol to a psychotic patient until the QT interval is calculated. Then, after the dose is given, the QT is supposed to be re-calculated to see if there has been a change.
Remember--haloperidol is given for PSYCHOSIS. If a patient is tearing out his IV's and foley, ripping off his clothes and running down the hall screaming and punching nurses--how much time do I have to calculate a prolonged QT?
When the policy of calculating QT intervals came out, the number of psychotic patients plummeted to zero. It was a medical miracle! There were no more psychotic patients in the whole hospital. We still had anxious patients, though. Lorazepam could be given to calm them down.
Beware of making the cure worse than the disease. If the right treatment is made too difficult, people will give the wrong one.