The use of intercostal nerve block (ICNB) for thoracic surgery can reduce pain in the first 24 hours after surgery and decrease opioid use, according to a systematic review and meta-analysis, published in JAMA Network Open, of 59 studies.
“We know that thoracic surgery is one of the most painful surgeries,” said Juan Cata, MD, assistant professor at the University of Texas M.D. Anderson Cancer Center in Houston. “As it is one of the most painful [surgeries], even when we provide anesthesia and give several medications, opioids remain the most common analgesic.”
Cata noted that his institution began using ICBN in part to decrease postoperative opioid use. He and his coinvestigators, therefore, reviewed the literature to determine if the use of ICNB after thoracic surgery has an opioid-sparing impact.
The review’s coprimary endpoints were postoperative pain intensity (measured as the worst static or dynamic pain using a validated 10-point scale, with 0 indicating no pain and 10 indicating severe pain) and use of opioids, which were measured in morphine milligram equivalents (MMEs) at prespecified intervals (0 – 6 hours, 7 – 24 hours, 25 – 48 hours, 49 – 72 hours, and >72 hours). Clinically relevant analgesia was defined as a 1-point or greater difference in pain intensity score at any interval. Investigators also looked at 30-day postsurgical complications and pulmonary function.
The use of ICNB, compared with systemic analgesia, was associated with lower static pain and lower dynamic pain up to 24 hours after surgery.
The study showed that ICNB is not inferior to thoracic epidural analgesia (TEA) and was marginally, but not clinically, inferior to paravertebral block (PVB). The use of ICNB, however, was associated with higher MME values than TEA (mean difference 48 hours after surgery, 48.31 MMEs; 95% CI, 36.11 – 60.52 MMEs) and PVB (mean difference 48 hours after surgery, 3.87 MMEs; 95% CI, 2.59 – 5.15 MMEs).
Maung Hlaing, MD, a cardiothoracic anesthesiologist and associate professor at the School of Medicine, University of Colorado, in Aurora, commented that the review suggests ICNB is preferred over systemic analgesics. “The main outcome is that the ICNB technique led to decreased opioid use and decreased pain scores compared to systemic analgesics,” he said. “The effect was most pronounced in the first 24 hours, which you would expect with a single-shot dose lasting anywhere from 12 to 16 hours. It would make sense that the effect was mostly in the first day. It is clear from this study and others that ICNB is better than systemic analgesia, that is getting no block and getting IV [intravenous] opioids.”
One of the limitations of the systematic review is that the studies that were examined were largely unblinded, Hlaing noted.
“It is a common problem, and it is very hard to do sham procedures,” he said. “Because of that, you end up with patients and providers who are aware of the procedures that the patients have had. For a subjective outcome such as pain, whether or not a patient had the procedure done becomes a big part of the analysis, and the risk of bias is there.”
Another limitation that Hlaing pointed out is that the measure of MME did not take into account morphine administered in a thoracic epidural. “In patients who get thoracic epidurals, these patients tend to get morphine in the epidural space as well, much of which is absorbed systemically,” he said. “They are getting morphine, but it is not counted [toward MMEs] because it is not in IV form.”
Cata and Hlaing have disclosed no relevant financial relationships.
JAMA Netw Open. 2021;4(11):e2133394, e2133839. Full text
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