Spinal 2-chloroprocaine: a dose-ranging study and the effect of added epinephrine.
With the availability of preservative- and antioxidant-free 2-chloroprocaine (2-CP), there may be an acceptable short-acting alternative to lidocaine for spinal anesthesia. We examined the safety, dose-response characteristics, and effects of epinephrine with spinal 2-CP. Six volunteers per group were randomized to receive 30, 45, or 60 mg of spinal 2-CP with and without epinephrine. Intensity and duration of sensory and motor blockade were assessed. When 11 of the 18 volunteers complained of vague, nonspecific flu-like symptoms, breaking of the blind revealed that all spinal anesthetics associated with the flu-like symptoms contained epinephrine. There were no complaints of flu-like symptoms in the volunteers who received 2-CP without epinephrine. No further spinal anesthetics containing epinephrine were administered, resulting in 29 anesthetics (11 with epinephrine, 18 without epinephrine.) Plain 2-CP demonstrated a dose-dependent increase in peak block height and duration of effect at all variables except time to 2-segment regression and time to regression to T10. Time to complete sensory regression with plain 2-CP was 98 +/- 20, 116 +/- 15, and 132 +/- 23 min, respectively. 2-CP with epinephrine produced times to complete sensory regression of 153 +/- 25, 162 +/- 33, and 148 +/- 29 min, respectively. Preservative and antioxidant free 2-CP can be used effectively for spinal anesthesia in doses of 30-60 mg. Epinephrine is not recommended as an adjunct because of the frequent incidence of side effects.


CONCLUSIONS
Hyperbaric spinal 2-chloroprocaine is effective and has an anesthetic profile appropriate for use in the surgical outpatient over the dose range of 30-60 mg without signs of transient neurologic symptoms. The addition of epinephrine is not recommended because of the frequent incidence of side effects.
Smith
Kristin N
KN
From the Department of Anesthesiology, Virginia Mason Medical Center, Seattle, Washington.
Kopacz
Dan J
DJ
McDonald
Susan B
SB
D000328:Adult; D000556:Ambulatory Surgical Procedures; D000775:Anesthesia, Spinal; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000009:adverse effects; D004305:Dose-Response Relationship, Drug; D004311:Double-Blind Method; D004576:Electromyography; D004837:Epinephrine; D005260:Female; D006801:Humans; D008012:Lidocaine / Q000008:administration & dosage / Q000009:adverse effects; D008297:Male; D009046:Motor Neurons / Q000187:drug effects; D009119:Muscle Contraction / Q000187:drug effects; D010147:Pain Measurement / Q000187:drug effects; D011343:Procaine / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives*; D014662:Vasoconstrictor Agents
D000779:Anesthetics, Local; D014662:Vasoconstrictor Agents; D011343:Procaine; C004616:chloroprocaine; D008012:Lidocaine; D004837:Epinephrine