Effects of Combined Antiemetic Protocol for the Prevention of Postoperative Nausea and Vomiting in Orthognathic Surgery: A Randomized Double Blinded Clinical Study

Abstract

Background

Postoperative nausea and vomiting (PONV) after orthognathic surgery remains one of the most common side effects despite the use of several medications.

Purpose

The study aimed to compare the frequencies of PONV between a combination of metoclopramide with granisetron and granisetron alone.

Study Design, Setting, Sample

A randomized double-blind clinical trial was conducted in 66 consecutive patients who underwent orthognathic surgery at the Department of Oral and Maxillofacial Surgery at Bezmialem Vakif University. Patients with contraindications such as hypersensitivity to medications, gastrointestinal or metabolic disorders, renal insufficiency, electrolyte imbalances, pregnancy, neurological diseases, prolonged QT interval, or mental retardation were excluded.

Predictor Variable

The predictor variable was the antiemetic treatment (combination vs single therapy). Participants were randomized to either the metoclopramide with granisetron group (group GM) or the granisetron-only group (group G).

Main Outcome Variable

The outcome variable was PONV status, measured using the simplified postoperative nausea and vomiting impact scale. The participants were assessed at baseline (when fully awake) and during the subsequent 24 hours.

Covariates

Patient characteristics, total drug doses, systolic and diastolic blood pressure, peripheral arterial oxygen saturation, Apfel’s PONV risk score, total bleeding volume, infused fluid volume, surgery duration, PONV incidence, visual analog scale scores, tramadol requirement, and the use of rescue antiemetics were determined as covariates.

Analyses

Data were analyzed using the Mann–Whitney U test with P value less than.05 considered significant.

Results

The sample consisted of 60 participants, with 30 patients in each treatment group. The mean age was 30 ± 11.6 years in group G and 25.63 ± 10 years in group GM (P = .1); 42% of participants were male (P = .8). PONV scores at the second hour were 1.56 ± 1.45 in group G and 0.79 ± 0.90 in group GM (P = .03). The difference between the groups was statistically significant (P < .001). Participants in group G had a 1.61-fold higher risk of vomiting than those in the group GM (Relative risk = 1.61; 95% CI, 1.313 to 1.962).

Conclusion and Relevance

Compared to granisetron alone, the combination of granisetron and metoclopramide was associated with significant PONV control in patients undergoing orthognathic surgery. A multimodal approach may be adopted to reduce the incidence of PONV in patients undergoing maxillofacial surgery.