Women who suffer grade 3 or 4 perineal lacerations during vaginal delivery consume significantly more opioids than their counterparts who do not, a study found, and virtually none of these women with higher-grade lacerations received neuraxial morphine. That finding surprised the researchers and illustrated the need for a department-wide protocol to address the analgesic needs of these patients.
“There has been very little data looking at pain scores after vaginal delivery complicated by perineal lacerations,” said Ashraf Habib, MD, professor of anesthesiology, obstetrics and gynecology, and chief of women’s anesthesia at Duke University Medical Center, in Durham, N.C. “One study [Reg Anesth Pain Med 2005;30:134-139] showed that epidural morphine administration offered modest benefit, but it was not targeted to patients with perineal lacerations.
“At our institution we sometimes give neuraxial morphine to these patients, but we don’t have a systematic way to do it. With that in mind, we thought we’d look at pain scores and analgesic requirements, as well as whether neuraxial morphine made any difference in these women.”
Study Followed 3 Groups
Dr. Habib and his colleagues reviewed the charts of 5,863 women who delivered at the institution’s labor unit between Jan. 1, 2014, and Dec. 4, 2015. The investigators extracted a variety of data from the electronic medical record, including patient demographics, obstetric details, the presence and degree of lacerations, and pain scores. They also recorded the amount of analgesics administered, including opioids, acetaminophen and nonsteroidal anti-inflammatory drugs, during the first 24 and 48 hours after delivery.
“We divided the patients into three groups,” Dr. Habib noted: “those who had no lacerations, those who had first- or second-degree lacerations, and those who had third- or fourth-degree lacerations.”
As Dr. Habib reported at the 2016 annual meeting of the American Society of Anesthesiologists (abstract A2079), 37% of the women in the analysis had no lacerations, 59% had first or second-degree lacerations, and 4% had third- or fourth-degree lacerations. “The groups were very similar with respect to clinical demographics, except that primips [i.e., primiparas] comprised a much greater percentage of the third- and fourth-degree tears,” he said. “The use of neuraxial techniques was more common in patients who had lacerations and instrumental deliveries, as you would expect.”
Perhaps not surprisingly, the groups differed significantly with respect to oral analgesic consumption and pain scores at both 24 and 48 hours among laceration groups (Table).
Table. Pain Scores and Analgesic Consumption in Patients With No or More Perineal Lacerations
No Laceration First/Second Degree Third/Fourth Degree P Value
Maximum, 0-24 hours 5.1±2.6 4.5±2.3 5.2±2.4 <0.0001
Mean, 0-24 hours 2.5±1.8 2.3±1.6 2.7±1.6 <0.0001
Maximum, 0-48 hours 4.0±2.8 3.6±2.5 4.1±2.5 <0.0001
Mean, 0-48 hours 2.3±2.0 2.0±1.7 2.3±1.7 0.0007
Acetaminophen (mg), 0-24 hours 552.0±859.7 454.9±800.5 599.6±864.5 <0.0001
Ibuprofen (mg), 0-24 hours 2,016.8±651.1 2,049.8±628.3 2,121.1±554.4 0.04
Oxycodone (mg), 0-24 hours 5.9±16.1 5.3±13.0 10.4±15.4 <0.0001
Acetaminophen (mg), 0-48 hours 888±1,396.6 708.3±1,262.1 973.5±1,353.5 <0.0001
Ibuprofen (mg), 0-48 hours 3,356.7±1,236.2 3,431.6±1,204.7 3,732.4±1,015.1 <0.0001
Oxycodone (mg), 0-48 hours 9.8±25.8 8.3±20.6 17.5±29.7 <0.0001
Need for oxycodone, n (%) 636 (60%) 967 (29%) 182 (85%) <0.0001
A multivariate analysis also was performed. After controlling for potential confounders, the presence of third- or fourth-degree lacerations was found to be significantly associated with the need for post-delivery oxycodone [odds ratio, 2.6; 95% CI, 1.76-3.87).
“Then we tried to look at the second part of our question, which was whether neuraxial morphine made a difference with respect to pain relief in these women,” Dr. Habib said. “Interestingly and surprisingly, we found that very few patients got neuraxial morphine. … So we couldn’t do this analysis because we didn’t have the patient population for it.
“But what this analysis suggested to us was that we need to introduce a system in our practice to give neuraxial morphine in a systematic way, so it’s not so hit and miss. Because if this is our aim, we’re not doing a very good job of it.”
“Is avoiding one 10-mg oxycodone tablet worth the side effects associated with neuraxial morphine?” asked Mark C. Norris, MD, clinical professor of anesthesiology at Boston University.
“You could argue that, depending on the extent of side effects and how much morphine you have to give,” Dr. Habib replied. “Typically we give 2 mg to these patients.”
“We did a study of neuraxial morphine in normal deliveries, without tears,” commented Richard M. Smiley, MD, PhD, chief of obstetric anesthesia at NewYork-Presbyterian Hospital/Columbia University Medical Center, in New York City. “And the doses we used were 1 or 2 mg. I remember that side effects were minimal. Our big concern was urinary retention, but we found no difference between the treatment groups and placebo. But we found that 1 mg of neuraxial morphine seemed to give us a benefit, with very few side effects.
“Now, if we know there’s a reasonably bad tear, we try to get a dose of epidural morphine in, although it’s usually 2 mg.”
“We routinely give 1.5 mg neuraxial morphine for third- or fourth-degree lacerations,” said Mark Rollins, MD, PhD, professor of anesthesia at the University of California, San Francisco. “There’s actually a 2013 study [Anesth Analg2013;117:677-685] where they compared 1.5 and 3 mg of neuraxial morphine for cesarean deliveries. And the side effects of the lower dose were incredibly minimal.”
Nevertheless, Dr. Habib and his colleagues acknowledged the need for more research to determine whether neuraxial opioids can reduce overall analgesic consumption and improve analgesia in these women.