… But use may not yet be optimized
According to a retrospective analysis of national claims data, use of IV acetaminophen is associated with modestly reduced perioperative opioid utilization and its related adverse effects in patients undergoing open colectomy. Patients given more than one dose of IV acetaminophen on the day of surgery had an 8% reduction in opioid utilization as well as decreased odds of respiratory complications (odds ratio [OR], 0.66; 95% CI, 0.58-0.75) compared with patients not receiving the drug.
“In open colectomy patients, getting more than one dose of IV acetaminophen on the day of surgery was associated with modest benefits and outcomes,” said Jashvant Poeran, MD, PhD, assistant professor of population health science and policy and assistant professor of medicine at Icahn School of Medicine at Mount Sinai, in New York City. “These findings warrant further discussion on its value in light of other nonopioid analgesic options.”
As Dr. Poeran reported at the 2017 spring meeting of the American Society of Regional Anesthesia and Pain Medicine (abstract 3880), questions remain regarding the value of IV acetaminophen in postoperative pain management, as small trials have provided inconclusive results concerning its opioid-sparing effects.
“The decision to use IV acetaminophen is something that we’ve struggled with at our institution,” Dr. Poeran said. “We were uncertain about the absolute value of its use, especially given the recent price hikes.”
So Dr. Poeran and colleagues sought a real-world, large-scale assessment of its use to determine whether the higher cost of IV acetaminophen could be offset by its ability to reduce opioid consumption and related adverse effects. For this retrospective study, the investigators searched national claims data from Premier Perspective for hospitalizations for open colectomy patients from January 2011 to December 2014.
In total, 112,156 open colectomy patients representing 511 hospitals were included in the analysis. The investigators looked for IV acetaminophen use, which was categorized as one dose (1,000 mg) or more than one dose on the day of surgery (day 0), the day after surgery (day 1) or later (day 1+).
After adjusting for potentially confounding variables, the team measured associations between IV acetaminophen use and:
- opioid utilization in oral morphine equivalents, and
- opioid-related adverse effects, including respiratory, gastrointestinal, central nervous system and genitourinary complications.
As Dr. Poeran reported, 20% of open colectomy patients (n=22,612) received IV acetaminophen. Of these patients, 48.8% (n=11,044) received only one dose on day 0, while 10% (n=2,266) and 35.1% (n=7,945) received one and more than one dose on day 1+, respectively.
“After adjusting for relevant covariates, we observed a pattern of modestly reduced opioid utilization paired with lower odds for opioid-related adverse effects,” said Dr. Poeran, who noted that this benefit was most pronounced in patients receiving more than one dose of IV acetaminophen on the day of surgery. These patients had a 7.7% reduction in opioid utilization and were significantly less likely to experience respiratory complications (OR, 0.66; 95% CI, 0.58-0.75). However, this pattern was largely absent for other opioid-related adverse effects, the investigators noted.
According to Dr. Poeran, use of IV acetaminophen also was associated with a higher use of other nonopioid analgesics. Moreover, patients receiving IV acetaminophen were “slightly healthier,” with a lower comorbidity index than patients not receiving the treatment (2.13 vs. 2.33; P<0.0001).
“Interestingly, IV acetaminophen use at least two days after surgery was associated with up to 24% increased opioid utilization, with higher significant odds for opioid-related adverse effects,” said Dr. Poeran, who speculated that this patient population may be in more pain and thus require more opioids. “With 49% of patients receiving only one dose on the day of surgery, we may not be using IV acetaminophen in the most effective way.”
Hospital length of stay and cost of hospitalization were found to be not closely correlated. Andres Missair, MD, associate professor of anesthesiology at the University of Miami Miller School of Medicine, wondered why this was so. “IV acetaminophen appears to be driving shorter length of stay, but the impact on cost of hospitalization is somewhat equivocal,” Dr. Missair said.
“Obviously length of stay is one of the big drivers of cost of hospitalization, so these results imply that there may be something else influencing that measure,” Dr. Poeran noted. “That being said, these effects are small. Before starting this study, we prespecified that a 20% reduction in opioid utilization, length of stay and/or cost would be of value. Although you see that reduction in some of these measures, the outcomes are modest.”
He added, “Having said that, IV acetaminophen is probably not being used in the most effective way. I think additional studies should focus on ways to optimize its use.”