The Incidence of Itching in Thoracic Epidural Morphine Applications: Can Laboratory Parameters Be Effective in Predicting Itching?

Background Epidural morphine, a powerful analgesic, also causes significant itching in patients. This study aimed to determine the incidence of thoracic epidural morphine-induced pruritus (EMIP) after thoracotomy and to investigate preoperative laboratory parameters for predicting itching in patients who received thoracic epidural morphine (TEM). Methods The patients were divided into two groups. The itching (+) group consists of patients who developed itching (n=31). The no-itching (-) / control group (n=31) was selected among patients who did not develop itching after TEM. Preoperative hemogram values, neutrophil/lymphocyte rate (NLR), platelet/lymphocyte rate (PLR), lymphocyte/monocytes rate (LMR), preoperative and postoperative alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase (ALP), gamma-glutamyl transferase values, and whether there was itching in the first 48 hours after surgery were determined. Results The incidence of thoracic EMIP after thoracotomy was 7.9%. While preoperative and postoperative ALP was found to be lower in patients with itching compared to those without itching. The cut-off value for preoperative/postoperative ALP was 84.5/53. Decreased white blood cell (WBC) could predict pruritus with a borderline statistical significance. Conclusions The incidence of EMIP after thoracotomy was lower compared to other literature data. Infusion of morphine only into the epidural area may cause a low incidence of EMIP. Laboratory parameters ALP and WBC can predict EMIP, but other hemogram parameters, NLR, LMR, and PLR cannot predict EMIP.