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Post-thoracotomy epidural analgesia: Lumbar or thoracic placement?
Post-Thoracotomy
Epidural
A
Analgesia:
NESTHESIOLOGISTS have improved postoperative pain management through 24-hour acute pain management services that offer a variety of techniques.’ Specifically, epidural analgesia has been shown to decrease postoperative morbidity and improve postoperative outcome in high-risk surgical patients.2.” Although epidural analgesia for postthoracotomy patients is not universally accepted, there is presently ample evidence to strongly recommend this technique over the available alternatives. Far more controversial is the question of lumbar versus thoracic placement of the epidural catheter. Hurford et aI4 contribute to this debate in an interesting study reported in this issue of the Journal of Cardiothoracic and Vascular Anesthesia. The significance of this study deserves a review of the pertinent literature and some critical commentary. Intermittent epidural morphine injections have been demonstrated to be safe5 and more effective than either intramuscular or intravenous morphine injections.6,7 Further, epidural morphine results in earlier ambulation, earlier recovery of pulmonary and bowel function, and shorter hospital stay compared with intramuscular morphine.6 Compared with intermittent morphine epidural injections, continuous morphine epidural infusions have been shown to provide equally effective analgesia with a reduced incidence of side effects and less demand of nursing time.8 Generalized concern of respiratory depression with epidural morphine led to investigation of fentanyl, a more lipophilic opioid, known to be more effective as an analgesic when used epidurally rather than intramuscularly.9 The ideal concentration of fentanyl infusion was found to be 10 pg/mL, with respect to analgesic effectiveness, onset, and incidence of side effects.iO Compared with a morphine epidural infusion, a fentanyl epidural infusion provides comparable analgesia with significantly lower incidence of nausea and pruritus.” Studies comparing epidural versus intravenous opioid infusions in patients with knee surgery,i2 cesarean section l3 and hysterectomyI show the two techniques to be equaily effective, suggesting that the opioid’s predominant mechanism of analgesic effect is systemic. The plasma opioid concentrations were similar in both the epidural and intravenous groupsi2; however, epidural technique showed lower incidence of somnolence.15 Though few would question the conclusions reached by the authors of these studies, they were limited by gender distribution and by operations that do not produce severe postoperative pain. Studies involving operative procedures that cause severe postoperative pain, such as gastroplasty6 or thoracotomies ‘,i6-20 suggest clinically significant benefits of epidural opioids compared with intravenous opioids. Studies using thoracotomy as the model can be subdivided into three categories: (1) those comparing intermittent epidural opioid injections with intermittent intravenous opioid injections demonstrating the epidural technique to be significantly more effective’; (2) those comparing epidural opioid infusions with intravenous opioid infusions; and (3) those comparing epidural opioid infusion to intravenous patientcontrolled analgesia (PCA). The latter two deserve considerable analysis. Journalofcardiofhoracic
and VascularAnesthesia,
Lumbar
or Thoracic
Placement?
On the surface, studies comparing epidural opioid infusions with intravenous opioid infusions appear to demonstrate conflicting results. One study placed the epidural catheter at the L2-3, L3-4 interspace and found the analgesia and the time course for the plasma fentanyl concentrations similar with both techniquesl$ whereas another inserted the epidural catheter at the T4-5 interspace and noted significantly lower infusion rates and plasma fentanyl concentrations with the epidural technique.” Another fentanyl infusion study18 compared catheter placements at LA-5 and T4-5 with the intravenous route and found no differences in the quality of analgesia or the total fentanyl dose delivered. However, the thoracic epidural patients had an earlier onset of bowel movement, better postoperative forced vital capacity and FEV,, and shorter hospital stay than patients in the other two groups. These three studies16-18 appear to demonstrate that thoracic epidural fentanyl infusions provide comparable analgesia and superior postoperative recovery when compared with either lumbar epidural or intravenous fentanyl infusions. In general, comparative studies of epidural opioid infusions with PCA show significantly greater effectiveness of the epidural technique regardless of the epidural placement leve1.19T20Thoracic (T3-4, T4-5) epidural fentanyl infusion with intravenous PCA morphine were compared2() and significantly lower visual analog pain scores, higher total pain relief scores and less sedation were found in the epidural group. Another study2* showed no difference in analgesia, hourly dose, cumulative dose, or plasma fentanyl concentrations between the two techniques. These studies7J7-20 demonstrate epidural opioid analgesia to be superior to intravenous opioid analgesia in the management of pain after thoracotomy. It is generally agreed that thoracic epidural placement is more difficult to perform and is associated with more risks, including increased incidence of respiratory depression, than lumbar placement 22; however, the benefits of thoracic placement are controversial. 23,24 In this issue of the Journal of Cardiothoracic and Vascular Anesthesia, Hurford et al4 compared lumbar and thoracic infusions of fentanyl with bupivacaine and found lower, but not statistically significant, pain scores in the thoracic group. However, patients in the lumbar group required significantly increased rates of fentanyl infusion to achieve comparable analgesia. Other studies using fentanyl alone 18.2shad similar findings, including earlier recovery of gastrointestinal and pulmonary functions and shorter hospital stay. It should be noted, however, that these advantages of thoracic placement do not apply to epidural infusions of morphine, which is less lipophilic than fentanyl. It is reasonable to arrive at the following conclusions based upon available data. First, intermittent epidural opioid injections provide significantly better analgesia than either intramuscular or intermittent intravenous opioid injections. Second, the analgesia provided by an intravenous opioid infusion is comparable to an epidural opioid
Key words: postoperative
analgesia,
anesthetic
techniques,
epidural,
intravenous
Vol7, No 5 (October), 1993: pp 515416
515
HONORIO T. BENZON
516
infusion in operations tive pain. Therefore,
that do not cause severe postoperathe patient
exposure
to added
risks
and the expensive resources required for epidural opioid infusions do not seem warranted when intravenous infusions can do as well. Third, in operations that produce severe postoperative pain (thoracotomy, extensive abdominal surgery), an epidural opioid infusion is superior to an intravenous opioid infusion. Fourth, thoracic epidural fentanyl infusions provide excellent analgesia and superior
postoperative sons,
thoracic
recovery after thoracotomy. epidural
placement
For these is recommended
postthoracotomy analgesia when appropriate pertise is available.
rea-
for technical ex-
Honorio T. Benzon, MD
Northwestern University Medical School Northwestern Memorial Hospital Chicago, IL
REFERENCES
1. Ready LB, Oden R, Chadwick HS, et al: Development of an anesthesiology-based postoperative pain management. Anesthesiology 68:100-106, 1988 2. Yeager MP, Glass DD, Neff RK, Brinck-Johnsen T: Epidural anesthesia and analgesia in high-risk surgical patients. Anesthesiology 661729-736, 1987 3. Tuman KJ, McCarthy RJ, March RJ, et al: Effects of epidural anesthesia and analgesia on coagulation and outcome after major vascular surgery. Anesth Analg 73:696-704, 1991 4. Hurford WE, Dutton RP, Alfille PH, et al: Comparison of thoracic and lumbar epidural infusions of bupivacaine and fentanyl for postthoracotomy analgesia. J Cardiothorac Vast Anesth 7:521525,1993 5. Ready LB, Loper KA, Nessly M, Wild L: Postoperative epidural morphine is safe on surgical wards. Anesthesiology 751452-456,1991 6. Rawal N, Sjostrand U, Christoffersson E, et al: Comparison of intramuscular and epidural morphine for postoperative analgesia in the grossly obese: Influence on postoperative ambulation and pulmonary function. Anesth Analg 63:583-592, 1984 7. Shulman M, Sandler AN, Bradley JW, et al: Postthoracotomy pain and pulmonary function following epidural and systemic morphine. Anesthesiology 61:569-575, 1984 8. El-Baz NM, Faber P, Jensik RJ: Continuous epidural infusion of morphine for treatment of pain after thoracic surgery: A new technique. Anesth Analg 63:757-764, 1984’ 9. Lomessy A, Magnin C, Viale JP, et al: Clinical advantages of fentanyl given epidurally for postoperative analgesia. Anesthesiology 61:466-469,1984 10. Welchew EA: The optimum concentration for epidural fentanyl. Anaesthesia 38:1037-1041, 1983 11. Fisher RL, Lubenow TR, Liceaga A, et al: Comparison of continuous epidural infusion of fentanyl-bupivacaine and morphinebupivacaine in management of postoperative pain. Anesth Analg 67:559-563, 1988 12. Loper KA, Ready LB, Downey M, et al: Epidural and intravenous fentanyl infusions are clinically equivalent after knee surgery. Anesth Analg 70:72-75, 1990 13. Ellis DJ, Millar WA, Reisner LS: A randomized doubleblind comparison of epidural versus intravenous fentanyl infusion for analgesia after cesarean section. Anesthesiology 72:981-986, 1990
14. Camu F, Debucquoy F: Alfentanyl infusion for postoperative pain: A comparison of epidural and intravenous routes. Anesthesiology 75:171-178, 1991 15. Camann WR, Loferski BL, Fanciullo GJ, et al: Does epidural administration of butorphanol offer any clinical advantage over the intravenous route? Anesthesiology 76:216-220, 1992 16. Sandler AN, Stringer D, Panos L, et al: A randomized, double-blind comparison of lumbar epidural and intravenous fentanyl infusions for postthoracotomy pain relief. Anesthesiology 77~626-634,1992 17. Salomaki TE, Laitinen JO, Nuutinen LS: A randomized double-blind comparison of epidural versus intravenous fentanyl infusion for analgesia after thoracotomy. Anesthesiology 75:790795,199l 18. Guinard JP, Mavrocordatos P, Chiolero R, Carpenter RL: A randomized comparison of intravenous versus lumbar and thoracic epidural fentanyl for analgesia after thoracotomy. Anesthesiology 77:1108-1115, 1992 19. Grant RP, Dolman JF, Harper JA, et al: Patient-controlled lumbar epidural fentanyl compared with patient-controlled intravenous fentanyl for postthoracotomy pain relief. Can J Anaesth 39:214-219, 1992 20. Benzon HT, Wong HY, Belavic A, et al: A randomized double-blind comparison of epidural fentanyl infusion versus patient-controlled analgesia with morphine for postthoracotomy pain. Anesth Analg 7:316-322, 1993 21. Glass PSA, Estok P, Ginsberg B. et al: Use of patientcontrolled analgesia to compare the efficacy of epidural to intravenous fentanyl administration. Anesth Analg 74:345-351, 1992 22. Gustafson LL. Schildt B, Jacobsen KJ: Adverse effects of extradural and intrathecal narcotics: report of a nationwide survey in Sweden. Br J Anaesth 54:479-486,1982 23. Fromme GA, Steidl LJ. Danielson DR: Comparison of lumbar and thoracic epidural morphine for relief of postthoracotomy pain. Anesth Analg 64:454-455, 1985 24. Bodily MN, Chamberlain DP, Ramsey DH, Olsson GL: Lumbar versus thoracic epidural catheter for postthoracotomy analgesia. Anesthesiology 71:A1146, 1989 25. Coe A, Sarginson R, Smith MW, et al: Pain following thoracotomy: A randomized, double-blind comparison of lumbar versus thoracic epidural fentanyl. Anaesthesia 46:918-921,199l
Epidural
A
Analgesia:
NESTHESIOLOGISTS have improved postoperative pain management through 24-hour acute pain management services that offer a variety of techniques.’ Specifically, epidural analgesia has been shown to decrease postoperative morbidity and improve postoperative outcome in high-risk surgical patients.2.” Although epidural analgesia for postthoracotomy patients is not universally accepted, there is presently ample evidence to strongly recommend this technique over the available alternatives. Far more controversial is the question of lumbar versus thoracic placement of the epidural catheter. Hurford et aI4 contribute to this debate in an interesting study reported in this issue of the Journal of Cardiothoracic and Vascular Anesthesia. The significance of this study deserves a review of the pertinent literature and some critical commentary. Intermittent epidural morphine injections have been demonstrated to be safe5 and more effective than either intramuscular or intravenous morphine injections.6,7 Further, epidural morphine results in earlier ambulation, earlier recovery of pulmonary and bowel function, and shorter hospital stay compared with intramuscular morphine.6 Compared with intermittent morphine epidural injections, continuous morphine epidural infusions have been shown to provide equally effective analgesia with a reduced incidence of side effects and less demand of nursing time.8 Generalized concern of respiratory depression with epidural morphine led to investigation of fentanyl, a more lipophilic opioid, known to be more effective as an analgesic when used epidurally rather than intramuscularly.9 The ideal concentration of fentanyl infusion was found to be 10 pg/mL, with respect to analgesic effectiveness, onset, and incidence of side effects.iO Compared with a morphine epidural infusion, a fentanyl epidural infusion provides comparable analgesia with significantly lower incidence of nausea and pruritus.” Studies comparing epidural versus intravenous opioid infusions in patients with knee surgery,i2 cesarean section l3 and hysterectomyI show the two techniques to be equaily effective, suggesting that the opioid’s predominant mechanism of analgesic effect is systemic. The plasma opioid concentrations were similar in both the epidural and intravenous groupsi2; however, epidural technique showed lower incidence of somnolence.15 Though few would question the conclusions reached by the authors of these studies, they were limited by gender distribution and by operations that do not produce severe postoperative pain. Studies involving operative procedures that cause severe postoperative pain, such as gastroplasty6 or thoracotomies ‘,i6-20 suggest clinically significant benefits of epidural opioids compared with intravenous opioids. Studies using thoracotomy as the model can be subdivided into three categories: (1) those comparing intermittent epidural opioid injections with intermittent intravenous opioid injections demonstrating the epidural technique to be significantly more effective’; (2) those comparing epidural opioid infusions with intravenous opioid infusions; and (3) those comparing epidural opioid infusion to intravenous patientcontrolled analgesia (PCA). The latter two deserve considerable analysis. Journalofcardiofhoracic
and VascularAnesthesia,
Lumbar
or Thoracic
Placement?
On the surface, studies comparing epidural opioid infusions with intravenous opioid infusions appear to demonstrate conflicting results. One study placed the epidural catheter at the L2-3, L3-4 interspace and found the analgesia and the time course for the plasma fentanyl concentrations similar with both techniquesl$ whereas another inserted the epidural catheter at the T4-5 interspace and noted significantly lower infusion rates and plasma fentanyl concentrations with the epidural technique.” Another fentanyl infusion study18 compared catheter placements at LA-5 and T4-5 with the intravenous route and found no differences in the quality of analgesia or the total fentanyl dose delivered. However, the thoracic epidural patients had an earlier onset of bowel movement, better postoperative forced vital capacity and FEV,, and shorter hospital stay than patients in the other two groups. These three studies16-18 appear to demonstrate that thoracic epidural fentanyl infusions provide comparable analgesia and superior postoperative recovery when compared with either lumbar epidural or intravenous fentanyl infusions. In general, comparative studies of epidural opioid infusions with PCA show significantly greater effectiveness of the epidural technique regardless of the epidural placement leve1.19T20Thoracic (T3-4, T4-5) epidural fentanyl infusion with intravenous PCA morphine were compared2() and significantly lower visual analog pain scores, higher total pain relief scores and less sedation were found in the epidural group. Another study2* showed no difference in analgesia, hourly dose, cumulative dose, or plasma fentanyl concentrations between the two techniques. These studies7J7-20 demonstrate epidural opioid analgesia to be superior to intravenous opioid analgesia in the management of pain after thoracotomy. It is generally agreed that thoracic epidural placement is more difficult to perform and is associated with more risks, including increased incidence of respiratory depression, than lumbar placement 22; however, the benefits of thoracic placement are controversial. 23,24 In this issue of the Journal of Cardiothoracic and Vascular Anesthesia, Hurford et al4 compared lumbar and thoracic infusions of fentanyl with bupivacaine and found lower, but not statistically significant, pain scores in the thoracic group. However, patients in the lumbar group required significantly increased rates of fentanyl infusion to achieve comparable analgesia. Other studies using fentanyl alone 18.2shad similar findings, including earlier recovery of gastrointestinal and pulmonary functions and shorter hospital stay. It should be noted, however, that these advantages of thoracic placement do not apply to epidural infusions of morphine, which is less lipophilic than fentanyl. It is reasonable to arrive at the following conclusions based upon available data. First, intermittent epidural opioid injections provide significantly better analgesia than either intramuscular or intermittent intravenous opioid injections. Second, the analgesia provided by an intravenous opioid infusion is comparable to an epidural opioid
Key words: postoperative
analgesia,
anesthetic
techniques,
epidural,
intravenous
Vol7, No 5 (October), 1993: pp 515416
515
HONORIO T. BENZON
516
infusion in operations tive pain. Therefore,
that do not cause severe postoperathe patient
exposure
to added
risks
and the expensive resources required for epidural opioid infusions do not seem warranted when intravenous infusions can do as well. Third, in operations that produce severe postoperative pain (thoracotomy, extensive abdominal surgery), an epidural opioid infusion is superior to an intravenous opioid infusion. Fourth, thoracic epidural fentanyl infusions provide excellent analgesia and superior
postoperative sons,
thoracic
recovery after thoracotomy. epidural
placement
For these is recommended
postthoracotomy analgesia when appropriate pertise is available.
rea-
for technical ex-
Honorio T. Benzon, MD
Northwestern University Medical School Northwestern Memorial Hospital Chicago, IL
REFERENCES
1. Ready LB, Oden R, Chadwick HS, et al: Development of an anesthesiology-based postoperative pain management. Anesthesiology 68:100-106, 1988 2. Yeager MP, Glass DD, Neff RK, Brinck-Johnsen T: Epidural anesthesia and analgesia in high-risk surgical patients. Anesthesiology 661729-736, 1987 3. Tuman KJ, McCarthy RJ, March RJ, et al: Effects of epidural anesthesia and analgesia on coagulation and outcome after major vascular surgery. Anesth Analg 73:696-704, 1991 4. Hurford WE, Dutton RP, Alfille PH, et al: Comparison of thoracic and lumbar epidural infusions of bupivacaine and fentanyl for postthoracotomy analgesia. J Cardiothorac Vast Anesth 7:521525,1993 5. Ready LB, Loper KA, Nessly M, Wild L: Postoperative epidural morphine is safe on surgical wards. Anesthesiology 751452-456,1991 6. Rawal N, Sjostrand U, Christoffersson E, et al: Comparison of intramuscular and epidural morphine for postoperative analgesia in the grossly obese: Influence on postoperative ambulation and pulmonary function. Anesth Analg 63:583-592, 1984 7. Shulman M, Sandler AN, Bradley JW, et al: Postthoracotomy pain and pulmonary function following epidural and systemic morphine. Anesthesiology 61:569-575, 1984 8. El-Baz NM, Faber P, Jensik RJ: Continuous epidural infusion of morphine for treatment of pain after thoracic surgery: A new technique. Anesth Analg 63:757-764, 1984’ 9. Lomessy A, Magnin C, Viale JP, et al: Clinical advantages of fentanyl given epidurally for postoperative analgesia. Anesthesiology 61:466-469,1984 10. Welchew EA: The optimum concentration for epidural fentanyl. Anaesthesia 38:1037-1041, 1983 11. Fisher RL, Lubenow TR, Liceaga A, et al: Comparison of continuous epidural infusion of fentanyl-bupivacaine and morphinebupivacaine in management of postoperative pain. Anesth Analg 67:559-563, 1988 12. Loper KA, Ready LB, Downey M, et al: Epidural and intravenous fentanyl infusions are clinically equivalent after knee surgery. Anesth Analg 70:72-75, 1990 13. Ellis DJ, Millar WA, Reisner LS: A randomized doubleblind comparison of epidural versus intravenous fentanyl infusion for analgesia after cesarean section. Anesthesiology 72:981-986, 1990
14. Camu F, Debucquoy F: Alfentanyl infusion for postoperative pain: A comparison of epidural and intravenous routes. Anesthesiology 75:171-178, 1991 15. Camann WR, Loferski BL, Fanciullo GJ, et al: Does epidural administration of butorphanol offer any clinical advantage over the intravenous route? Anesthesiology 76:216-220, 1992 16. Sandler AN, Stringer D, Panos L, et al: A randomized, double-blind comparison of lumbar epidural and intravenous fentanyl infusions for postthoracotomy pain relief. Anesthesiology 77~626-634,1992 17. Salomaki TE, Laitinen JO, Nuutinen LS: A randomized double-blind comparison of epidural versus intravenous fentanyl infusion for analgesia after thoracotomy. Anesthesiology 75:790795,199l 18. Guinard JP, Mavrocordatos P, Chiolero R, Carpenter RL: A randomized comparison of intravenous versus lumbar and thoracic epidural fentanyl for analgesia after thoracotomy. Anesthesiology 77:1108-1115, 1992 19. Grant RP, Dolman JF, Harper JA, et al: Patient-controlled lumbar epidural fentanyl compared with patient-controlled intravenous fentanyl for postthoracotomy pain relief. Can J Anaesth 39:214-219, 1992 20. Benzon HT, Wong HY, Belavic A, et al: A randomized double-blind comparison of epidural fentanyl infusion versus patient-controlled analgesia with morphine for postthoracotomy pain. Anesth Analg 7:316-322, 1993 21. Glass PSA, Estok P, Ginsberg B. et al: Use of patientcontrolled analgesia to compare the efficacy of epidural to intravenous fentanyl administration. Anesth Analg 74:345-351, 1992 22. Gustafson LL. Schildt B, Jacobsen KJ: Adverse effects of extradural and intrathecal narcotics: report of a nationwide survey in Sweden. Br J Anaesth 54:479-486,1982 23. Fromme GA, Steidl LJ. Danielson DR: Comparison of lumbar and thoracic epidural morphine for relief of postthoracotomy pain. Anesth Analg 64:454-455, 1985 24. Bodily MN, Chamberlain DP, Ramsey DH, Olsson GL: Lumbar versus thoracic epidural catheter for postthoracotomy analgesia. Anesthesiology 71:A1146, 1989 25. Coe A, Sarginson R, Smith MW, et al: Pain following thoracotomy: A randomized, double-blind comparison of lumbar versus thoracic epidural fentanyl. Anaesthesia 46:918-921,199l