Letters to the Editor
Case Report: Extrapyramidal CNS Toxicity from a Lidocaine Epidural
TO THE EDITOR: A 29-year-old woman (gravida -1) with an estimated gestational age of 38 weeks presented with spontaneous rupture of membranes. Her obstetric and medical history was unremarkable. Oxytocin (Pitocin) was initiated to augment labor. A continuous lumbar epidural was placed seven hours after spontaneous rupture of membranes, and adequate analgesia was obtained without evidence of adverse side effects.
Because the patient failed to dilate, she consented to a low transverse cesarean delivery 18 hours after spontaneous rupture of membranes. Anesthesia was provided via the previously placed epidural. The surgery was performed without complications, and a healthy female infant with Apgar scores of 8 and 9 was delivered. A total of 40 mL of 2 percent lidocaine with epinephrine (Xylocaine with epinephrine) was administered via continuous lumbar epidural during the operation.
Twenty minutes after her last lidocaine infusion, the patient became confused, disoriented, and did not recognize her husband. She alternated non-blinking staring at the ceiling with agitation and attempts to get out of bed. Lip smacking and tremulous hand movements also were noted. Vital signs remained stable. The certified registered nurse anesthetist recognized the extrapyramidal signs of lidocaine toxicity during operating room transfer, and the patient was rapidly given a total of 5 mg of intravenous midazolam (Versed). Within 30 minutes, she was awake, alert, and oriented. She described feelings of anxiety, depersonalization, and confusion during the episode.
Systemic lidocaine toxicity from a properly placed epidural is a rare side effect that occurs approximately 0.2 percent of the time.1 This reaction normally occurs immediately after an improperly placed epidural catheter enters the vascular spaces or cerebrospinal fluid rather than the epidural space. Very little lidocaine diffuses out of the central nervous system (CNS) into circulation, where it is rapidly metabolized by the liver. Signs of CNS toxicity can include tremors, confusion, agitation, and staring. Approximately one in 1,000 may progress to seizures,2 and death is a remote possibility. Treatment is symptomatic and supportive. The lidocaine infusion must first be stopped. Benzodiazepines can reverse the CNS signs and raise the seizure threshold, but also may work synergistically with lidocaine to depress respiratory drive.
There are no known pre-existing risk factors for developing this reaction.3,4 Rapid recognition of epidural lidocaine toxicity is the key to treatment and resolution.
REFERENCES
1. Dawkins CJ. An analysis of the complications of extradural and caudal block. Anaesthesia 1969;24:554-63.
2. Ralston DH, Shnider SM. The fetal and neonatal effects of regional anesthesia in obstetrics. Anesthesiology 1978;48:34-64.
3. Berde CB. Strichatz local anesthetics. In: Miller RD, ed. Anesthesia. 5th ed. Philadelphia: Churchill Livingstone, 2000:511.
4. Brown DL. Spinal, epidural, and caudal anesthesia. In: Miller RD, ed. Anesthesia. 5th ed. Philadelphia: Churchill Livingstone, 2000:1513.
Cutaneous Warts: Is Surgical Excision Still A Viable Option?
TO THE EDITOR: I enjoyed the article on therapy for cutaneous warts1 in the August 15, 2005, issue of American Family Physician. However, the authors did not discuss surgical excision of cutaneous warts. Many family physicians and surgeons still practice this therapeutic option in some parts of the world, especially in Africa, where the other methods are not readily available. I have had to surgically excise genital warts while practicing in Mozambique, one of the poorest countries in the world. Is there evidence to support the efficacy of this treatment method, or should it be considered completely outdated?
REFERENCES
Bacelieri R, Johnson SM. Cutaneous warts: an evidence-based approach to therapy. Am Fam Physician 2005;72:647-52.
Duct Tape Is an Effective Treatment for Common Warts
TO THE EDITOR: In their article,1 "Cutaneous Warts: An Evidence-Based Approach to Therapy," Drs. Bacelieri and Johnson presented a well-organized and easy-to-follow evidence-based approach to common warts. However, I was mildly surprised that there was no mention of duct tape. In the February 1, 2003, issue of American Family Physician, the "POEMs and Tips from Other Journals" department presented a review2 of an article3 in which the cure rates for common warts were statistically higher using duct-taping (85 percent of warts completely resolved) than for those treated with cryotherapy (65 percent of warts completely resolved).
In actual practice, I first counsel my patients about the benefits and drawbacks of salicylic acid, cryotherapy, and duct tape. Even though the cost of cryotherapy is higher and the cure rates may not be, most of my patients still seem to prefer that route. However, a handful never came back to see me after they decided to use duct tape to treat themselves.
REFERENCES
1. Bacelieri R, Johnson SM. Cutaneous warts: an evidence-based approach to therapy. Am Fam Physician 2005;72:647-52.
2. Miller KE. Duct tape more effective than cryotherapy for warts (Tips). Am Fam Physician 2003;67:614.
3. Focht DR III, Spice C, Fairchok MP. The efficacy of duct tape vs cryotherapy in the treatment of verruca vulgaris (the common wart). Arch Pediatr Adolesc Med 2002;156:971-4.
IN REPLY:The letters from Dr. Monjok and Dr. Viel made excellent points, and I would like to address each one separately.
In response to Dr. Monjok's question of whether surgical excision is still a viable option for warts: Surgical excision for warts is impractical as a cure because cutaneous warts are caused by a virus that often exists on normal appearing skin outside of the confines of the clinical wart. On multiple occasions, I have seen a "doughnut wart" or clinical wart around a surgical site. With that information, it is still a worthwhile practice to debulk a large clinical wart to improve patient comfort in areas of the world where more effective treatments are unavailable.
In reply to Dr. Viel, duct tape occlusion is an effective treatment for warts, as noted in the study by Focht and colleagues.1 In my practice, I often use over-the-counter salicylic acid or prescription 40 percent urea gel under occlusion with duct tape for plantar warts. I personally find it difficult to use duct tape for common warts on other locations.
REFERENCES
1. Focht DR III, Spice C, Fairchok MP. The efficacy of duct tape vs cryotherapy in the treatment of verruca vulgaris (the common wart). Arch Pediatr Adolesc Med 2002;156:971-4.
Send letters to Kenny Lin, M.D., Contributing Editor, American Family Physician, e-mail: afplet@aafp.org. Letters submitted via regular mail should be sent (on disk) to: 11400 Tomahawk Creek Pkwy., Leawood, KS 66211-6272.
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