GP4b - The Effects of Dexmedetomidine on Anesthetic Outcomes following Maxillomandibular Advancement Surgery

Abstract: Research supports that maxillomandibular advancement (MMA) surgery is an effective treatment modality for severe obstructive sleep apnea (OSA). In a systematic review, Ankichetty, et al, found that the use of alpha 2 agonists in OSA patients reduces the requirement of perioperative analgesics, but no randomized clinical trials with the use of dexmedetomidine (DEX) in OSA patients exist.1 Furthermore, while there are several studies evaluating peri-operative parameters in patients who have undergone Stanford Protocol’s Phase I OSA surgeries, published studies regarding the usage of intra-operative DEX and anesthetic outcomes following MMA surgery are difficult to find. The authors seek to elucidate the effects that DEX, an alpha 2 agonist with analgesic, amnesic, and supposed anesthesia-sparing properties, has on patients immediately following MMA surgery.2

A search through the sponsoring institution’s electronic medical record system was conducted from January 1, 2017, through December 31, 2020, using Current Procedural Terminology codes for bilateral sagittal split ramus osteotomy (BSSRO), Le Fort I osteotomy with or without bone grafts (LFI), genioplasty, genioglossus advancement, and/or genial bone graft (GG). Two independent investigators (ADC and YJL) reviewed the resultant charts and selected adult patients aged 18 years and older with a diagnosis of OSA. Patients who remained intubated at the conclusion of MMA surgery and whose procedures included solely revision osteotomies were excluded from this study. The remaining 58 patient records underwent a detailed retrospective chart review. Postoperative opioid requirement was calculated as milligrams (mg) of morphine equivalent dosages (MEDs). Univariate analysis was conducted with Pearson’s Chi-square to determine the presence of a statistically significant association between cumulative doses of intraoperative DEX and the opioid requirement within the first 8- and 24-hours postoperatively, as well as the time from "Surgery End to Extubation" (EXT). Multiple linear regression and multinomial logistic regression were utilized to evaluate relationships among different doses of medications received and to calculate odds ratios, respectively. Significance was defined as P < .05.

There were 58 patients included in this study: 47 (81%) males and 11 (19%) females; 27 (46.6%) had received intraoperative DEX and 31 (53.4%) had not. While all patients underwent at least 2 osteotomies, 49 (84.5%) of patients underwent 4 (i.e., LF1, BSSRO, and GG osteotomies). There was no significant difference detected between cumulative dosage of intraoperative DEX and first 8-hour postoperative narcotic requirement (P = .30). However, a statistically significant association was detected between cumulative dosage of intraoperative DEX and first 24-hour postoperative narcotic requirement (P = .02). Furthermore, patients who received a cumulative DEX dose between 100.1 and 200 micrograms (mcg) received less opioids within the first 24-hour postoperative period than those patients who received > 200mcg of DEX. EXT in patients who received between 100.1 and 200mcg of DEX, as compared to those who did not receive and those who did receive lower amounts of intraoperative DEX, was statistically significantly higher (P = .01 and .02, respectively).

In contrary to the conclusions of Ankichetty, et al, and Bamgbade, et al, less intraoperative DEX was found to be significantly associated with lower 24-hour postoperative opioid requirements. This study also suggests that EXT may decrease with lower doses of DEX administered intraoperatively. Well-designed prospective, randomized studies involving larger numbers of patients with OSA undergoing MMA surgery and receiving DEX are warranted.

References:
1. Ankichetty, et al: A systematic review of the effects of sedatives and anesthetics in patients with obstructive sleep apnea. Journal of Anesthesiology Clinical Pharmacology 27:4, 2011
2. Bamgbade OA, Alfa JA: Dexmedetomidine anesthesia for patients with obstructive sleep apnea undergoing bariatric surgery. Eur J Anaesthesiol 26(2):176-7, 2009