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Correspondence  |   November 1996
Radicular Irritation after Spinal Anesthesia
Author Notes
  • Donald H. Lambert, Ph.D., M.D., Chief, Anesthesiology, Associate Chief, Surgical Services, Brockton-West Roxbury VAMC, West Roxbury, Massachusetts, Associate Professor of Anaesthesia, Harvard Medical School, Boston, Massachusetts.
  • Laura A. Lambert, M.D., Resident in Surgery, Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.
  • Gary R. Strichartz, Ph.D., Vice Chairman for Research, Director, Anesthesia Research Laboratories, Brigham and Women's Hospital, Boston, Massachusetts, Professor of Anaesthesia (Pharmacology), Harvard Medical School, Boston, Massachusetts.
Article Information
Correspondence
Correspondence   |   November 1996
Radicular Irritation after Spinal Anesthesia
Anesthesiology 11 1996, Vol.85, 1216-1217. doi:
Anesthesiology 11 1996, Vol.85, 1216-1217. doi:
To the Editor:-In their recent article concerning transient radicular irritation, Pollock et al. [1] incorrectly represented our earlier work. They wrote that our study of the neurotoxic potential of commercially available local anesthetics used for spinal anesthesia in sciatic nerves [2] "showed that 5% hyperbaric lidocaine, 0.5% tetracaine, and 0.75% bupivacaine caused nonreversible ablation of the stimulated compound action potential." Although it is true that 5% lidocaine and 0.5% tetracaine abolished the compound action potential, 0.75% bupivacaine did not.
This is important, because the reports of cauda equina syndrome after continuous spinal anesthesia implicate lidocaine and tetracaine, but not bupivacaine. [3,4] In addition, lidocaine, but not bupivacaine, produces the so-called transient radicular irritation syndrome. [1,5-9] In our study, [2] 0.75% bupivacaine, the highest concentration of bupivacaine used clinically, did not cause nerve injury. It is our opinion that bupivacaine is probably the safest local anesthetic for intrathecal use because it is the only local anesthetic that, to our knowledge, has not caused neural injury in patients, and it shows the least toxicity from intrathecal infusions in rats [10,11] or exposure to isolated nerves in vitro. [2] In addition, intrathecal infusions of clinical concentrations of bupivacaine are nontoxic in dogs. [12,13] 
Donald H. Lambert, Ph.D., M.D., Chief, Anesthesiology, Associate Chief, Surgical Services, Brockton-West Roxbury VAMC, West Roxbury, Massachusetts, Associate Professor of Anaesthesia, Harvard Medical School, Boston, Massachusetts.
Laura A. Lambert, M.D., Resident in Surgery, Department of Surgery, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire.
Gary R. Strichartz, Ph.D., Vice Chairman for Research, Director, Anesthesia Research Laboratories, Brigham and Women's Hospital, Boston, Massachusetts, Professor of Anaesthesia (Pharmacology), Harvard Medical School, Boston, Massachusetts.
(Accepted for publication August 19, 1996.)
REFERENCES
Pollock J, Neal J, Stepheson C, Wiley C: Prospective study of the incidence of transient radicular irritation in patients undergoing spinal anesthesia. Anesthesiology 1996; 84:1361-7.
Lambert LA, Lambert DH, Strichartz GR: Irreversible conduction block in isolated nerve by high concentrations of local anesthetics. Anesthesiology 1994; 80:1082-93.
Rigler ML, Drasner K, Krejcie TC, Yelich SJ, Scholnick FT, DeFontes J, Bohner D: Cauda equina syndrome after continuous spinal anesthesia. Anesth Analg 1991; 72:275-81.
Schell R, Brauer F, Cole D, Applegate RL II: Persistent sacral nerve root deficits after continuous spinal anaesthesia. Can J Anaesth 1991; 38:908-11.
Schneider M, Ettlin T, Kaufmann M, Schumacher P, Urwyler A, Hampl K, von Hochstetter A: Transient neurologic toxicity after hyperbaric subarachnoid anesthesia with 5% lidocaine. Anesth Analg 1993; 76:1154-7.
Pollock J, Mulroy M, Stephenson C: Spinal anesthetics and the incidence of transient radicular irritation [abstract]. Anesthesiology 1994; 81:A1029.
Hampl KF, Schneider MC, Ummenhofer W, Drewe J: Transient neurologic symptoms after spinal anesthesia. Anesth Analg 1995; 81:1148-53.
Hampl KF, Schneider MC, Thorin D, Ummenhofer W, Drewe J: Hyperosmolarity does not contribute to transient radicular irritation after spinal anesthesia with hyperbaric 5% lidocaine. Reg Anesth 1995; 20:363-8.
Tarkkila P, Huhtala J, Tuominen M: Transient radicular irritation after spinal anaesthesia with hyperbaric 5% lignocaine. Br J Anaesth 1995; 74:328-9.
Li D, Bahar M, Cole G, Rosen M: Neurological toxicity of the subarachnoid infusion of bupivacaine, lignocaine or 2-chloroprocaine in the rat. Br J Anaesth 1985; 57:424-9.
Drasner K, Sakura S, Chan VW, Bollen AW, Ciriales R: Persistent sacral sensory deficit induced by intrathecal local anesthetic infusion in the rat. Anesthesiology 1994; 80:847-52.
Kroin JS, Carthy RJM, Kerns JM, Ivankovich AD, Peen RD: The effect of chronic subarachnoid bupivacaine infusion in dogs. Anesthesiology 1987; 66:737-42.
Ganem E, Vianna P, Marques M, Castiglia Y, Vane L: Effects of increasing bupivacaine concentrations on spinal cord. Experinmental study in dogs. Reg Anesth 1993; 18:41.