Letters to the Editor: Letters & Announcements
To the Editor:
Brull et al. (1) attempt to report a single rate for neurological complications after central neuraxial blockade and peripheral nerve blockade and conclude that permanent deficits are rare.
Variable definitions, heterogeneity, and underreporting do certainly make it difficult to estimate incidence confidently. However, providing a rate for “neurological complications” and “permanent injury” without including cases of epidural hematoma and abscess (which are important, direct, and severe complications of central neuraxial blockade) may cause confusion. Also, no single incidence figure can be provided because the risk of a severe complication may differ up to 100-fold between patients at low risk (i.e., the obstetric population) (2,3) and those with multiple “red flags” for a serious complication of central neuraxial blockade, such as older age, female sex, degenerative spinal disorder, and concurrent anticoagulant treatment, a common scenario in the population undergoing total joint replacement (4). Data from the ASA Closed Claims database support the impression that significant deficits are much less likely in the obstetric population (5).
In Moen et al.'s (6) study, a severe neurologic complication (from all causes) occurred after 1:3600 epidural procedures and 1:20,000 spinal blocks in the general population, but the rate was greater in women undergoing total knee arthroplasty who had epidurals (1:1800) and lower in obstetric patients (1:25,000). We have found this a useful guide when considering risk-benefit of central neuraxial blockade on a patient-by-patient basis (7). Temporary neuropathy (e.g., <12 wk) is of questionable significance in a discussion of material risk during the patient consent process, especially if sensory only. Further data are keenly awaited, especially regarding rate of neurological injury after peripheral nerve blockade, using single-shot versus continuous-catheter techniques.
Steven J. Fowler, FCARCSI, FANZCA
Department of Anaesthesia Medicine
The Alfred Hospital
1. Brull R, McCartney CJ, Chan VW, El-Beheiry H. Neurological complications after regional anesthesia: contemporary estimates of risk. Anesth Analg 2007;104:965–74
2. Scott DB, Hibbard BM. Serious non-fatal complications associated with extradural block in obstetric practice. Br J Anaesth 1990;64:537–41
3. Palot M, Visseaux H, Botmans C, Pire JC. [Epidemiology of complications of obstetrical epidural analgesia]. Cahiers d'anesthesiologie 1994;42:229–33
4. Schroeder DR. Statistics: detecting a rare adverse drug reaction using spontaneous reports. Reg Anesth Pain Med 1998;23:183–9
5. Lee LA, Posner KL, Domino KB, Caplan RA, Cheney FW. Injuries associated with regional anesthesia in the 1980s and 1990s: a closed claims analysis. Anesthesiology 2004;101:143–52
6. Moen V, Dahlgren N, Irestedt L. Severe neurological complications after central neuraxial blockade in Sweden 1990–1999. Anesthesiology 2004;101:950–9
7. Sage D, Fowler SJ. Major neurologic injury following regional anesthesia. In: Finucane BT, ed. Complications of regional anesthesia. 2nd ed. New York: Springer, 2007:333–53