Regional Anesthesia Benefits Kidney Recipients
CHICAGO—Regional anesthesia significantly reduces nausea and opioid use in the first two days after kidney transplantation, new findings suggest.
A retrospective study presented at the American Society of Anesthesiologists' 2011 annual meeting showed that 30 kidney recipients given a transversus abdominis plane (TAP) block enjoyed these benefits compared with 30 individuals with intravenous, patient-controlled analgesia.
None of the patients was given epidural anesthesia because of either reduced or dysfunctional platelets. Furthermore, the team analyzed only the first 48 post-operative hours because longer catheter use can lead to bacterial colonization and thus is not recommended.
The median morphine-equivalent dose of opioids was 33.7 among people with a TAP catheter compared with 238 in the standard-care patients, a significant difference between the groups. Moreover, the study, led by Maged Guirguis, MD, and Ehab Farag, MD, of the Department of Anesthesiology at Cleveland Clinic, showed that the average nausea score was lower in the TAP group compared with controls (1.00 vs. 1.06) in the controls. Average pain intensity on a verbal rating scale also was lower in the TAP-catheter group, but not statistically significant (2.2 vs. 2.6).
“Theoretically if your opioid requirement decreases, all the complications related to postoperative opioids usage also decrease, such as nausea, ileus, respiratory depression and the increased potential for infection,” Dr. Guirguis, MD, told Renal & Urology News. “Overall the patient satisfaction also was high among those with TAP catheters.”
Transplant surgeons at the University of Michigan Health Systems in Ann Arbor, put the study findings into perspective. “There are a fair number of studies out now, in colorectal, gynecology, and other abdominal operations, using this technique and I have not been overwhelmed by the results, though it may be an effective alternative to epidural anesthesia,” said Christopher Sonnenday, MD, MHS, Assistant Professor of Surgery and Assistant Professor of Health Management & Policy. “In the kidney transplant population, incisional pain is usually not a prohibitive problem and we don't use epidural catheters.”
A colleague, Randall Sung, MD, Associate Professor of Surgery, agreed that more study is needed to show whether TAP catheters are indeed the best analgesia approach in some kidney recipients.
“The major advantage presented in the data appears to be nausea—however, resumption of oral intake isn't a big issue in this population, so I'm not sure it's a major improvement,” Dr. Sung said. “It would seem that TAP has advantages over epidurals, but the devil is in the details—ease of use, logistics, transition to oral pain medication, etc.”
The TAP block involves delivery of local anesthetic to the region between the internal oblique muscle and the transversus abdominus muscle. It has the advantage of continuous analgesia via a catheter compared to other regional nerve blocks such as paravertebral or the combination of intercostal with ilioinguinal or iliophypogastric, Dr. Guirguis and his colleagues explained in their poster. They also state that the literature shows TAP catheters have been used successfully for pain relief after abdominal procedures such as hernia repair, hysterectomy, cesarean delivery, and suprapubic prostatectomy (Reg Anesth Pain Med 2006;31:91). It is used in some transplant recipients at the Cleveland Clinic, according to Dr. Guirguis and his co-investigators, to avoid the side effects associated with opioids and the potential for trouble with epidural use in patients with platelet dysfunction.
They concede that the small sample size and retrospective nature of their study limit its potential clinical implications, and plan a study that will be more robust.
“The aim of our future prospective study is to measure the incidence of complications for a longer period of time and also to recruit a bigger sample,” Dr. Guirguis said.