Although dexamethasone may be a beneficial adjunct to surgery in terms of its antiemetic and anti-inflammatory effects, a team of researchers from Thomas Jefferson University Hospital has found that it may have a darker side, particularly in diabetic patients.
A pilot study concluded that dexamethasone administration was associated with significant postoperative hyperglycemia in these patients when undergoing functional endoscopic sinus surgery (FESS), which ultimately may lead to poorer outcomes.
“Dexamethasone is routinely requested by our ENT [ear, nose and throat] surgeons,” said Adam Setren, MD, a resident at Thomas Jefferson University Hospital, in Philadelphia. “From the anesthesia literature, we know it is a key component in the prevention of nausea and vomiting. From a surgical perspective, there’s a commonly held conception—and some evidence to suggest—that it improves operating conditions, decreases inflammation, and may be associated with decreased bleeding and operative times, specifically in sinus surgery.
“By the same token, the side effects of corticosteroids are well known and legion—the most important short-term side effect is hyperglycemia,” Dr. Setren said. “And both steroids as well as hyperglycemia itself are associated with poor outcomes in a variety of ways, including impaired wound healing and infection.”
Given these potential adverse events, the researchers sought to determine the prevalence of hyperglycemia in the immediate postoperative period in patients with diabetes mellitus who received dexamethasone during elective FESS.
The investigators reviewed the records of 14,307 patients (19,006 surgeries) who underwent elective outpatient ENT surgery at the institution between 2011 and 2015. Perioperative and outpatient records were reviewed for a number of variables, including age, sex, body mass index, preoperative hemoglobin A1clevels, perioperative blood glucose measurements and diagnosis coding indicating the presence of diabetes mellitus. Intraoperative records were reviewed for the presence or absence of dexamethasone, time of administration, and length of surgery.
“Our primary outcome was blood glucose measurement in the PACU, which we compared with the preoperative glucose measurement,” Dr. Setren said.
Large Database Whittled Down to Few
Once the investigators limited their search to patients undergoing FESS, they were left with 3,945 procedures in 3,419 patients; dexamethasone was administered in 3,026 cases (77%). After applying various exclusion criteria, 46 cases were identified in 43 diabetic patients who underwent FESS and had recorded postoperative blood glucose measurements. Dexamethasone was given intraoperatively in 24 cases and not given in 22.
As Dr. Setren reported at the 2016 annual meeting of the American Society of Anesthesiologists (abstract A3018), diabetic patients who received dexamethasone demonstrated a significant increase in blood glucose from preoperative to postoperative measurements (P<0.001).
“Preoperatively, these patients had a mean blood glucose of 155 [mg/dL],” Dr. Setren said. “Postoperatively, the mean value for these patients climbed to 248 [mg/dL].”
Of note, the researchers did not find a significant difference between preoperative and postoperative glucose measurements when comparing patients with insulin-dependent versus non–insulin-dependent diabetes mellitus (P=0.151). What’s more, the study did not find an association between changes in blood glucose and age (P=0.837), body mass index (P=0.435) or length of surgery (P=0.793).
“By comparison, the group that did not receive dexamethasone did not see a significant change in their glucose levels,” Dr. Setren said. “This would support our view that functional endoscopic sinus surgery is not a physiologically stressful procedure, and it may serve as a model for observing the interaction between the administration of corticosteroids and blood glucose in the perioperative period.”
The analysis was not without its limitations. For instance, the group of patients that received dexamethasone had higher preoperative blood glucose levels than their counterparts who did not receive the agent. “So the decision to administer or avoid dexamethasone may well be influenced by the presence of preoperative hyperglycemia,” he explained.
A second limitation was the fact that a small percentage of patients actually had their blood glucose levels recorded both preoperatively and postoperatively. “We started with a very large patient sample, and found that many of them had missing data or did not have a recorded finger stick in the PACU,” he explained.
“That’s certainly an opportunity for quality improvement for us. We can be more vigilant in our institution about glycemic control in these patients, especially knowing that patients who received this medication had had altered blood glucose afterwards.”
Olubukola Nafiu, MD, congratulated the researchers on their efforts, and questioned whether the results of the analysis could have been affected by dexamethasone’s onset of action. “One of the things we know is that the dose of dexamethasone that is used for a number of surgical procedures does not appear to have an effect on what happens in the PACU, just by virtue of the fact that it takes a long time to work,” said the associate professor of anesthesiology at University of Michigan Health System, in Ann Arbor. “So, I wonder if this delayed onset of action somehow affected your findings.”
“Dexamethasone’s long duration of activity could mean that we are potentially missing the peak hyperglycemic values postoperatively, as sinus surgery patients are usually discharged home the same day of surgery,” commented Tara Kennedy, MD, assistant professor of anesthesiology at Thomas Jefferson University Hospital, who was the lead author of the study.
Session moderator Karen R. Boretsky, MD, associate in perioperative anesthesia and pain medicine at Boston Children’s Hospital and assistant professor of anesthesia at Harvard Medical School, in Boston, echoed these sentiments. “Previous studies indicate that when it comes to dexamethasone, you don’t get onset of action for as long as six hours. So since you’re looking at ambulatory surgery patients, you might just be getting the tip of the iceberg.”
“We were looking very early, not as far as six hours out,” Dr. Setren replied. “On average these are two-hour–long surgeries, and then they’re in the PACU for an hour or two. So we might not even be seeing the full effect of the dexamethasone.
“Our next step would hopefully be a prospective study to evaluate these results and examine their effect on perioperative morbidity,” he added.