In 30 to 40 percent of patients, however, this effect of NO is not clinically important. Systemic and pulmonary hemodynamics, blood gas tensions and biochemical markers of NO activity will be compared with and without dipyridamole. Dr. Cronin's preliminary data suggest that melatonin, a circadian hormone, is suppressed in postoperative patients. This study aims to determine whether restoration of physiologic levels of nocturnal melatonin will restore more normal sleep patterns in postoperative patients. The second aim of this study is to determine whether perioperative melatonin causes a clinically significant reduction in sleep-associated hypoxia.
Hypoxia is associated with postoperative sleep disturbance.
If postoperative sleep disturbance is prevented through the use of melatonin, the hypoxia associated with the sleep disturbance might also be prevented. In the modern era, anesthesia is typically provided by at least two drugs in combination. When delivering anesthesia using an intravenous technique, for example, most often a sedative such as propofol is used to provide unconsciousness and a morphine-type drug such as fentanyl is administered to produce pain relief. Unfortunately, much of the current knowledge that guides administration of these drugs is based on investigations in which only a single drug was studied. These solo drug studies are not fully applicable to today's multidrug practice patterns.