Dexamethasone Compared with Metoclopramide in Prevention of Postoperative Nausea and Vomiting in Orthognathic Surgery

Purpose: Prevention of postoperative nausea and vomiting (PONV) for orthognathic surgery is very important because of intermaxillary fixation. The aim of this study is to compare the eff ic iency of dexamethasone and metoclopramide in prevention of PONV. Materials and Methods: 22 patients age 15-50, ASA I-II, undergoing orthognathic surgery were randomly allocated in two groups. Group D n=11 –using dexamethasone 8 mg IV and Group M n=11using metoclopramide10 mg IV. The incidence and severity of PONV was evaluated for 24 hours postoperatively based on scoring system: 0=no emetic symptoms, 1=nausea, 2=vomiting. Whereas the severity of nausea was assessed using a four-point Likert scale, with 0=none, 1=mild, 2=moderate, 3=severe. Results: There was significant difference among the groups in the incidence of moderate to severe nausea (2-3 Likert scale) in the dexamethasone group 9.0 % compared to the metoclopramide group 27.2%, in early post-operative period (0-6 hrs). During late post-operative period (6-24 hrs), no significant difference was found between groups. There was significant difference among the groups in incidence of vomiting or retching (score 2) in early post-operative period (0-6 hrs), in-group D was 0% compared with 18.1% in-group M. In late post-operative period (6-24 hrs) in-group D no patient suffered from vomiting or retching, whereas in-group M 9.0% which was statistically insignificant. Conclusions: The prophylactic administration of 8 mg of IV dexamethasone, one-minute prior induction of anesthesia, reduces the incidence of PONV during the first 24 h postoperatively, with no increase in adverse side effects or delay in PACU discharge, when com-pared with the intravenous metoclopramide 10 mg, in patients undergoing orthognathic surgery. Introduction Postoperative nausea and vomiting (PONV) is one of the most frequent side effects of general anesthesia, particularly unpleasant and undesirable for the patient. Factors, influencing PONV development include female gender, age, nonsmoking status, previous history of PONV or motion sickness, general anesthesia, type and duration of surgery, and use of intraand postoperative opioids[i]. PONV for years has been called and remains the "big little problem" [ii] . Despite the achievements in the field of anesthesia the discovery of new anesthetics and antiemetic Overall incidence of PONV ranges from approximately 20 to 30%[iii], while in “high-risk” patients this incidence remains very high-around 70%[iv]. The overall incidence of PONV seems to be lower in patients undergoing maxillofacial operations compared with those in other surgical disciplines. However, swallowed blood and secretions stimulate the gag reflex and may make nausea and vomiting worse, and as it may be detrimental to the operative area. It is another risk factor for postoperative airway obstruction especially in orthognatic surgery where all patients will have intermaxillary fixation. Since propofol is associated with, a lower incidence of PONV compared with inhalational agents [v] [vi] [vii] [viii] propofol anesthesia may be a good choice for orthognathic surgery. PONV can cause a prolonged post anesthesia care unit (PACU) stay, patient discomfort, and can cause serious complications such as aspiration, electrolyte imbalance, increased bleeding, and wound dehiscence[ix], therefore increasing medical costs[x]. To our best knowledge, there is a lack of information about incidence of PONV in patients undergoing orthognathic surgery. This study is designated to evaluate the efficacy of dexamethasone and metoclopramide for preventing postoperative nausea and vomiting in patients undergoing orthognathic surgery, the PONV incidence in these patients and comparing emetic episodes between groups.