care screening, not perioperative medicine. It should be approached as such. Ronald P. Olson Preoperative Screening Unit Duke University Medical Center Durham, NC ron.olson@duke.edu David Lubarsky, MD, MBA Emanuel M. Papper Professor and Chair Department of Anesthesiology, Perioperative Medicine and Pain Management University of Miami/Jackson Memorial Hospital Miami, FL REFERENCES 1. Shander A, Javidroozi M, Goodnough, LT. Anemia screening in elective surgery: definition, significance and patients’ in- terests. Anesth Analg 2006;103:778 –9. 2. Olson RP, Stone A, Lubarsky D. The prevalence and significance of low preop- erative hemoglobin in ASA 1 or 2 outpa- tient surgery candidates. Anesth Analg 2005;101:1337– 40. 3. United States Preventive Services Task Force. Guide to clinical preventive services, 2nd ed. Chapter 22, Screening for iron deficiency anemia–including iron prophy- laxis. Baltimore: Williams & Wilkins, 1996: 231– 46. 4. Centers for Disease Control and Preven- tion. Recommendations to prevent and control iron deficiency in the United States. MMWR 1998;47(No. RR-3):1–29. 5. American Academy of Family Physicians (AAFP). Summary of recommendations for clinical preventive services. Revision 6.0. Leawood, KS: American Academy of Family Physicians (AAFP), 2005. 6. Institute of Medicine. Iron deficiency ane- mia: recommended guidelines for the pre- vention, detection, and management among U.S. children and women of childbearing age. Washington, DC: National Academy Press, 1993. DOI: 10.1213/01.ANE.0000227131.66561.22 Electrophysiology Studies Without Fluoroscopy To the Editor: We wish to thank Dr. Katz (1) for a well-presented review of the literature and acknowledge the simplicity of a well-conducted prospective observa- tional trial investigating radiation ex- posure of anesthesia personnel in an electrophysiology laboratory. However, we would like to point out an alternative means of con- ducting electrophysiological stud- ies (EPS) that avoids radiation exposure. In more than 70% of total EPS and catheter-ablation proce- dures performed at our institution, we safely and effectively use three- dimensional electroanatomical map- ping system guidance (NavX™; St. Jude Medical, St. Paul, MN) without fluoroscopy for patients with normal cardiac anatomy and right-sided problems, such as atrioventricular (AV) node reentry tachycardia and some AV reentry tachycardia. For some procedures, for example, those requiring transseptal catheterization and those requiring mapping and ablation of pathways that cause tachyarrhythmias in patients with abnormal cardiac anatomies, we use limited fluoroscopy. But even in these instances, we use a minimal amount of fluoroscopy to place the catheter in specific locations, and we can perform most of the rest of the procedure without fluoroscopy un- der NavX™ guidance. We share the same concerns as Dr. Katz regarding the radiation exposure and believe that newer non-fluoroscopic 3D electroanatomi- cal mapping systems will signifi- cantly limit this exposure to those of us who care for these patients. Luis M. Zabala, MD Michael L. Schmitz, MD Sana Ullah, MB ChB, FRCA W. Bryan Watkins, MD Division of Cardiothoracic Anesthesia zabalaluis@uams.edu Volkan Tuzcu, MD Director of Electrophysiology and Pacing Arkansas Children’s Hospital Little Rock, Arkansas REFERENCE 1. Katz JD. Radiation exposure to anesthesia personnel: the impact of an electrophysi- ology laboratory. Anesth Analg 2005;101: 1725– 6. DOI: 10.1213/01.ANE.0000227144.84027.4E In Response: I greatly appreciate the comments by Zabala et al. (1) regarding my article on radiation exposure among anesthe- siologists (2). I am encouraged by their report of an alternative technology for conducting electrophysiological stud- ies that offers the promise of reduced radiation exposure. Although my study focused only on the electrophysiological labora- tory, that is only the tip of the “radiation iceberg” for exposure among anesthesiologists. Almost every month a new fluoroscopically controlled, “noninvasive” proce- dure appears in our operating rooms and radiology suites. Such procedures undoubtedly benefit our patients, but they are a poten- tial source of cumulative radiation- induced injury to anesthesiologists and surgeons alike. Innovations such as nonfluoroscopic three-dimensional electroanatomical mapping will be necessary if clinicians are to avoid the adverse consequences of excessive ra- diation exposure. Jonathan D. Katz, MD Clinical Professor of Anesthesiology Yale University School of Medicine Chair, ASA Committee on Occupational Health jonathan.katz@yale.edu REFERENCES 1. Zabala LM, Schmitz ML, Ullah S, et al. Electrophysiology studies without fluo- roscopy. Anesth Analg 2006;103:780. 2. Katz JD. Radiation exposure to anesthesia personnel: the impact of an electrophysi- ology laboratory. Anesth Analg 2005;101: 1725– 6. DOI: 10.1213/01.ANE.0000227145.28196.A5 Does Excessive “Searching” Increase the Risk of Neural Trauma in Peripheral Nerve Blockade? To the Editor: We read with interest the article by Voelckel et al. (1) and commend the authors for highlighting the im- portance of routinely determining the lower current threshold at which electrolocation occurs, thus possibly reducing the risk of subse- quent neuropathy. The overriding concern of the clinical practitioner (especially the inexperienced one) is to achieve a successful block, and the focus becomes the upper cur- rent threshold of electrolocation. It would be interesting to know whether more attempts at needle insertion and redirection were re- quired in the group randomized to lower current. Such attempts could have increased the risk of direct 780 Letters to the Editor ANESTHESIA & ANALGESIA Letters to the Editor