In randomized clinical trial study, fifty patients with ASA class I and II who were candidates for elective thoracic surgery ,randomly divided into two equal groups . All thoracotomy were performed by the same surgeon.Exclusion criteria are history of allergies to opioid, addiction to alcohol or narcotics.
In intervention group, One hour prior to general anesthesia induction, a trans-dermal fentayl patch (Duragesic 50 μg/h) was placed on anterolateral skin of the thorax. Anesthetic method was the same in all of them. After thoracotomy, the patients were transferred to ICU and their entrance time to ICU was considered as the time zero and they were monitored for 72 hours.
Vital signs of the patients including heart rate, Systolic and Diastolic blood pressure and respiratory rate in ICU were measured and recorded every six hours.
In group M, we used 4 mg of IV morphine sulfate every 6 hours after thoracotomy.Pain score of the patients was evaluated with facial expression type of Visual Analogue Scale (VAS)and recorded throughout the next 72 hours after thoracotomy in 0, 2, 4, 6 and every 6 hours afterwards and a minute prior to IV morphine.
In each groups in case of need and expressing pain by the patient with a VAS more than II, 4 mg of intravenous morphine was injected as supplementary analgesia. At the end of the study VAS and the amount of Morphine necessary for analgesia in the two groups was compared.