| ||||||||||||||
|
|
|||||||||||||

Departments of
*Anesthesiology and
Surgery, Duke University Medical Center, Durham, North Carolina
Address correspondence and reprint requests to Stephen M. Klein, MD, Department of Anesthesiology, Box 3094, Duke University Medical Center, Durham, NC 27710. Address e-mail to klein006{at}mc.duke.edu
| Abstract |
|---|
|
|
|---|
Implications: Paravertebral nerve block has the potential to offer long-lasting pain relief and few postoperative side effects when used for breast surgery. We demonstrated that paravertebral nerve block, when compared with general anesthesia, is an alternative technique for breast surgery that may offer pain relief superior to general anesthesia alone.
| Introduction |
|---|
|
|
|---|
At our institution, PVB has been used to provide operative and immediate postoperative analgesia for breast cancer surgery (6). In initial nonrandomized trials, it has provided excellent unilateral chest wall anesthesia, a low frequency of postoperative nausea and vomiting, and low supplemental analgesic requirements (7). We report a randomized, prospective study comparing thoracic PVB with GA.
| Methods |
|---|
|
|
|---|
Patients were assigned by prerandomized, sealed envelopes to receive one of two different anesthetics: Group 1, GA (n = 30); and Group 2, PVB, thoracic level T17 (n = 30)
Patients randomized to receive GA were premedicated with 0.52.0 mg of midazolam IV. Anesthesia was induced with propofol 1.52 mg/kg IV and fentanyl 13 µg/kg IV. Succinylcholine 2 mg/kg IV was used to facilitate the intubation of the trachea. Anesthesia was maintained with isoflurane and nitrous oxide in oxygen. Fentanyl 12 µg/kg IV was administered at the discretion of the anesthesiologist. No further muscle relaxants were administered after tracheal intubation.
Patients randomized to receive a PVB were sedated in the sitting position by using 15 mg of midazolam IV and 100250 µg of fentanyl IV. The blocks were performed, by using the technique described by Moore (8) and Katz (9), by one senior resident and attending anesthesiologists experienced in the technique. The superior aspects of the spinous processes of thoracic levels T17 were identified. The needle entry site was marked 2.5 cm lateral to each spinous process ipsilateral to the operative breast. When surgery involved both breasts, PVB was performed bilaterally. By using a 22-gauge, 3.5-inch Quincke spinal needle attached via extension tubing to a syringe, the needle was advanced anteriorly in the parasagittal plane (perpendicular to the back in all directions) until it contacted the transverse process. The needle was then withdrawn to the subcutaneous tissue and angled to walk off the caudad edge of the transverse process. From the caudad edge, it was then advanced anteriorly approximately 1 cm. After aspiration of the syringe, 4 mL of 0.5% bupivacaine with 1:400,000 fresh epinephrine was injected at each of the seven levels. The patient was then returned to the supine position and sensation was assessed by using pin-prick. After assuring adequate anesthesia, the patient was transferred to the operating room. Intraoperative sedation was provided with propofol 3070 µg · kg-1 · min-1 IV, titrated to moderate sedation, with patients being arousable on command. Intermittent doses of 25 µg of fentanyl IV and 10 mg of propofol IV were given for supplemental sedation.
As a prophylactic antiemetic, all patients were treated with 4 mg of ondansetron IV, 30 min before the end of the procedure. At the conclusion of surgery, all patients were transferred to the PACU. Patients were medicated with either morphine 2050 µg/kg IV or fentanyl (if there was a previous adverse reaction to morphine) 0.20.5 µg/kg IV repeated every 5 min as necessary to relieve severe pain, rated by using the visual analog scale (VAS) greater than 3. Results are reported as morphine equivalents (fentanyl 10 µg = morphine 1 mg). For nausea or vomiting, patients received 4 mg of ondansetron IV.
Procedural data were collected, including the time to perform the GA (the time from monitor placement until intubation) and the time to place the PVB (the time from monitor placement until positioned supine). The need for reblock and the need for intraoperative local anesthetic supplementation by the surgeon were noted. In addition, the total intraoperative fentanyl dose administered to each patient was recorded. A research assistant unaware of the anesthetic technique collected postoperative patient data.
Patients were asked to record their pain by using a verbal analog pain score (0 = no pain to 10 = worst pain imaginable) and a VAS (0 mm = no pain to 100 mm = worst pain imaginable). Nausea was measured by using a verbal rating score (0 = no nausea to 10 = vomiting). Verbal scores for pain were collected postoperatively at 30 min, 60 min, 24 h, 48 h, and 72 h. If patients were discharged from the hospital, VAS for pain was used to measure later time points. These measurements were recorded on written forms at 24, 48, and 72 h and submitted by mail. Nausea scores were collected at 30 min, 60 min, and 24 h. In addition, patients were asked to record when they first felt able to resume their daily routine.
Descriptive statistics for demographics, procedural data, and intraoperative narcotics were produced. In addition, pain and nausea scores were analyzed. Statistical analysis for this study used a continuity-corrected, Wilcoxons two-sample test with a 0.05 two-sided significance level to test whether the proportion of patients reporting pain and nausea in the GA group was statistically different from that in the PVB group. This test was also used to compare responses from the two groups for each variable. For the purposes of the power determination, the two groups were taken to be of equal size, n = 30 per group. Parametric data were reported as mean ± SD.
| Results |
|---|
|
|
|---|
|
|
|
|
| Discussion |
|---|
|
|
|---|
These data were corroborated by a threefold increase in the GA groups requirement for supplemental analgesics in the first hour in the PACU, compared with that used in the PVB group. The analgesic effect of PVB appears to last longer than would be predicted based on local anesthetic kinetics alone (10). The explanation for this prolonged effect is unclear. When compared with other forms of central neuraxial block (e.g., epidural anesthesia) (5), PVB has been shown to be uniquely effective in eliminating cortical responses to thoracic dermatomal stimulation. This may perhaps inhibit a central reflex involved in pain. However, further work is needed to clarify the etiology of this extended pain relief.
In addition, the data demonstrated lower nausea and vomiting scores at 30 minutes, 1 hour, and 24 hours in the PVB group; however, only the value at 24 hours was statistically significant (P = 0.04). The lower scores may, in part, be the result of improved analgesia and the need for less postoperative opioids. Despite the lack of statistical significance, the fact that the overall nausea scores were lower in the PVB group is encouraging. The incidence of nausea and vomiting in this patient population is particularly high. The fact that measurements at earlier times failed to meet statistical significance, may be attributable to the low overall nausea scores recorded by patients. This may, in part, be caused by the universal use of prophylactic antiemetics in the study or perhaps the small sample size.
Frequently, labor-intensive anesthetic techniques do not gain acceptance because of their requirement for operating room time. Clearly, significantly more time was involved (24 minutes) to place the PVB than the 4 minutes used to induce the general anesthetic (P = 0.0001). This is definitely a disadvantage for a technique that requires positioning and multiple injections. However, using a monitored preoperative holding area to place the blocks may be one way to avoid this problem. Another disadvantage of PVB is the potential inadvertent injection or spread into the epidural space. The paravertebral space lies directly adjacent to the intervertebral foramina and in close proximity to the epidural space. Further, because the space also contains vascular structures, aspiration for blood before injection is essential. This potential for spread emphasizes the lack of a definitive end point when entering the paravertebral space. Pleura of the lung extends down to the level of T-12. Another technical complication could be a pneumothorax from deep needle penetration at the thoracic level. Although these complications were not noted in this series of patients, further prospective studies on a large patient population are necessary to evaluate overall safety of the technique.
In conclusion, this study demonstrated improved postoperative analgesia from PVB at 30 minutes (P = 0.0005), 1 hour (P = 0.0001), and 24 hours (P = 0.04) and may last as long as 72 hours, when compared with GA alone, for cosmetic breast surgery. In addition, there was a trend of less postoperative nausea in those treated with a PVB; however, this was only statistically significant at 24 hours (P = 0.04). Despite the additional time required on behalf of the anesthesiologist, the technique offers patients postoperative benefits that may justify the increased effort. We conclude that PVB is an alternative technique for cosmetic breast surgery that may offer superior pain relief and decreased nausea than GA alone.
| Acknowledgments |
|---|
| References |
|---|
|
|
|---|
This article has been cited by other articles:
![]() |
C. Luyet, U. Eichenberger, R. Greif, A. Vogt, Z. Szucs Farkas, and B. Moriggl Ultrasound-guided paravertebral puncture and placement of catheters in human cadavers: an imaging study Br. J. Anaesth., April 1, 2009; 102(4): 534 - 539. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. McElwain, N. M. Freir, C. L. Burlacu, D. C. Moriarty, D. I. Sessler, and D. J. Buggy The Feasibility of Patient-Controlled Paravertebral Analgesia for Major Breast Cancer Surgery: A Prospective, Randomized, Double-Blind Comparison of Two Regimens Anesth. Analg., August 1, 2008; 107(2): 665 - 668. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Sidiropoulou, O. Buonomo, E. Fabbi, M. B. Silvi, G. Kostopanagiotou, A. F. Sabato, and M. Dauri A Prospective Comparison of Continuous Wound Infiltration with Ropivacaine Versus Single-Injection Paravertebral Block After Modified Radical Mastectomy Anesth. Analg., March 1, 2008; 106(3): 997 - 1001. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. F. Moller, L. Nikolajsen, S. A. Rodt, H. Ronning, and P. S. Carlsson Thoracic Paravertebral Block for Breast Cancer Surgery: A Randomized Double-Blind Study Anesth. Analg., December 1, 2007; 105(6): 1848 - 1851. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. F. White Choice of peripheral nerve block for inguinal herniorrhaphy: is better the enemy of good? Anesth. Analg., April 1, 2006; 102(4): 1073 - 1075. [Full Text] [PDF] |
||||
![]() |
S. M. Klein, H. Evans, K. C. Nielsen, M. S. Tucker, D. S. Warner, and S. M. Steele Peripheral Nerve Block Techniques for Ambulatory Surgery Anesth. Analg., December 1, 2005; 101(6): 1663 - 1676. [Abstract] [Full Text] [PDF] |
||||
![]() |
P. M. Kairaluoma, M. S. Bachmann, A. K. Korpinen, P. H. Rosenberg, and P. J. Pere Single-Injection Paravertebral Block Before General Anesthesia Enhances Analgesia After Breast Cancer Surgery With and Without Associated Lymph Node Biopsy Anesth. Analg., December 1, 2004; 99(6): 1837 - 1843. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. M.-H. Ho, M. K. Karmakar, M. Cheung, and G. C. S. Lam Right thoracic paravertebral analgesia for hepatectomy Br. J. Anaesth., September 1, 2004; 93(3): 458 - 461. [Abstract] [Full Text] [PDF] |
||||
![]() |
C. C. Buckenmaier III, S. M. Klein, K. C. Nielsen, and S. M. Steele Continuous Paravertebral Catheter and Outpatient Infusion for Breast Surgery Anesth. Analg., September 1, 2003; 97(3): 715 - 717. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. A. Terheggen, F. Wille, I. H. Borel Rinkes, T. I. Ionescu, and J. T. Knape Paravertebral Blockade for Minor Breast Surgery Anesth. Analg., February 1, 2002; 94(2): 355 - 359. [Abstract] [Full Text] [PDF] |
||||
![]() |
N. W. Doss, J. Ipe, T. Crimi, S. Rajpal, S. Cohen, R. J. Fogler, R. Michael, and J. Gintautas Continuous Thoracic Epidural Anesthesia with 0.2% Ropivacaine Versus General Anesthesia for Perioperative Management of Modified Radical Mastectomy Anesth. Analg., June 1, 2001; 92(6): 1552 - 1557. [Abstract] [Full Text] [PDF] |
||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|