Opioid Use Before Abdominal Wall Repair Raises Post-op Requirement

Patients who use opioids before abdominal wall repair (AWR) have a greater need for opioids while in the hospital, and their stay may be longer than for patients who do not use the drugs before surgery, according to research presented at the Americas Hernia Society 2016 meeting.

“We were beginning to see the impact of opioid use on our patient group, even preoperatively,” said Bruce Ramshaw, MD, professor and chair of surgery at the University of Tennessee Graduate School of Medicine, in Knoxville. “We wanted to know the impact of opioid use on patients who have been using them—for back pain, hernia pain or some other problem—prior to surgery.”

Searching the literature, he found little information on opioid use in patients undergoing elective AWR, although an abstract presented at an academic surgical conference suggested an association between preoperative opioid use and higher costs and morbidity after abdominal surgery.

“Also, there is growing evidence that the opioids we use for postoperative pain management lead to patients becoming addicted or using opioids long term,” Dr. Ramshaw said.

To investigate these questions about opioid use in preoperative AWR, Dr. Ramshaw and his colleagues delved into their ongoing clinical quality improvement (CQI) research, a continuous collection of data and interpretation exempt from HIPAA and institutional review board (IRB) protocols. He explained a few differences between CQI research and traditional research.

“In CQI research, there [are] no inclusion or exclusion criteria. We can measure all sorts of outcomes, but most importantly those that measure value. The data can be used in real time in the real world by the clinical team. It’s a very efficient use of data, ideally using a multidisciplinary team to program what goes into the analytics and interpret the results,” Dr. Ramshaw said.

“For years, we have been applying CQI to subprocesses or fragments of patient care, but the real potential is to apply these principles to the whole cycle of patient care and measure outcomes that define value in the context of each definable patient care process,” he added.

Archana Ramaswamy, MD, a surgeon and associate professor at the University of Minnesota, in Minneapolis, and a staff surgeon at the Minneapolis VA, said that whereas the primary aim of traditional research is to generate scientific knowledge, data generated by CQI are meant to be used internally, to make local program changes. The fact that CQI research is not appropriate to go through the lengthy IRB process allows it to be accessed more quickly by the health care team and used to apply process improvement ideas in an attempt to improve outcomes.

“Dr. Ramshaw has been talking about CQI and how this form of data collection could help us better serve patients for many years, and finally we seem to be catching up with him,” she noted.

There are, however, disadvantages to CQI.

“Real-world data is very messy. It’s stored in many disparate repositories, which makes it difficult to get to,” Dr. Ramshaw said. “The most challenging aspect is cost data.”

Reviewing the data they had been collecting on ventral hernia patients retrospectively and prospectively over roughly a five-year period, Dr. Ramshaw and his colleagues found that 47 of the 102 patients (47%) they treated were already taking opioids. Patient characteristics and demographics, including number of previous abdominal surgeries, were similar between opioid users and nonusers, although smoking was more common in the opioid-using group.

The main outcome—total use of morphine equivalents during hospitalization—was significantly higher in patients using opioids before surgery than in nonusers, at 340.24 compared with 165.59 (P=0.0016). The morphine equivalents, in which one unit equals 1 mg IV morphine, were determined using an online calculator (www.globalrph.com/?narcotic.cgi). “There was a slightly shorter length of stay in the nonuse group, but it wasn’t statistically significant,” Dr. Ramshaw said.

The researchers concluded that patients who use opioids before AWR have a higher opioid requirement during their hospitalization, and that this may lead to a longer stay.

“Opioid use or overuse is a hot topic right now, and recognition that patients who are already using opioids may constitute a higher-risk population for AWR allows us to identify another area for risk modification,” Dr. Ramaswamy said. “The next step may be to see if multimodal opioid-sparing therapy, pre- and postoperatively, allows these patients to have similar outcomes to the opioid-naive ones.”

Dr. Ramshaw noted that this CQI research project won’t stop with one study, but paves the way for further investigation.

“We continue to ask questions and apply knowledge,” he said. “Now we’re wondering if weaning patients off preoperative opioid use would help in terms of opioid requirement in the hospital and length of stay.” A colleague has had good results with a program aimed at weaning pregnant women off opioids. “We’re thinking about how we could apply that to some of our presurgical patients as part of what is being called ‘prehabilitation.’”

Another question the researchers plan to investigate is whether opioid-naive patients become addicted to the opioids used for postoperative pain management, and how to manage that problem.