This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Katz, J. D. Search for Related Content PubMed PubMed Citation Articles by Katz, J. D. Related Collections Operating Rooms Complications Technology

---

TECHNOLOGY, COMPUTING, AND SIMULATION

Radiation Exposure to Anesthesia Personnel: The Impact of an Electrophysiology Laboratory

Clinical Professor of Anesthesiology, Yale University School of Medicine, New Haven, Connecticut

Address correspondence to Jonathan D. Katz, MD, 9 Morris St., Hamden, Ct. 06517. Address e-mail to jonathan.katz{at}yale.edu.

	Abstract

Top Abstract Introduction Methods Results Discussion References

 
Anesthesia care providers are vulnerable to radiation exposure during a number of diagnostic and therapeutic procedures. In this study I examined the radiation exposure to members of a small department of anesthesiology. The aggregate radiation exposure to all members of the department doubled subsequent to the introduction of an electrophysiology laboratory.

	Introduction

Top Abstract Introduction Methods Results Discussion References

 
Radiation exposure has long been identified as a potential occupational hazard among health care workers (1). The few studies that have focused on anesthesia care providers (ACPs) were conducted before the widespread use of many of the modern diagnostic and therapeutic procedures that rely on fluoroscopic guidance (2–4). This study was designed to examine the change in radiation exposure absorbed by ACPs in one department after the introduction of an electrophysiology laboratory (EPL).

	Methods

Top Abstract Introduction Methods Results Discussion References

 
The study took place in a 330-bed community hospital located in the northeastern United States. The IRB of the hospital in which the study was conducted approved the study.

With the exception of the introduction of the EPL, there was no other significant change in case mix during the time interval of the study. There was no attempt to control case assignments. Each of the ACPs spent some time in the EPL during the course of the study. However, because of departmental scheduling conventions, certain members of the department were more likely than others to be assigned to the EPL. One of the subjects left the department before completion of the study and three began employment and were enrolled after the study had begun.

ACPs wore standard lead aprons and thyroid collars during cases that used fluoroscopy. In addition, a lead-lined screen was placed in the EPL between the source of radiation and the anesthetizing location. Each ACP was given a radiation dosimeter (Landauer, Inc. Glenwood, Ill) and instructed to wear it at chest level outside any shielding aprons. The badges were collected and analyzed monthly. Exposure was reported in millirems (mrem). A report of "M" ("minimal") was issued for any badge that registered below the minimum measurable quantity (<1 mrem). For purposes of analysis, any M designation was assigned an exposure of 1 mrem.

Radiation exposure for each individual was aggregated into 2 time intervals: "PRE": collected in the 6 mo before the opening of the EPL (January 1 to June 30, 2003) and "POST": collected in the 6 mo subsequent to the establishment of the EPL (January 1 to June 30, 2004).

Data were analyzed using Microsoft Excel 2000® and SAS Release 8.02®; (SAS, Cary, NC). Statistical analysis was accomplished using a paired Student’s t-test.

	Results

Top Abstract Introduction Methods Results Discussion References

 
There were 6337 anesthetic cases, with zero EPL cases, in the 6 mo before the opening of the EPL (PRE). There were a total of 6820 anesthetic cases, including 212 EPL cases, in the 6 mo subsequent to its opening (POST). The total radiation exposure reported for the entire department was 503 mrem (mean ± sd, 16.77 ± 29.76 mrem) PRE and 1006 mrem (mean ± sd, 33.53 ± 41.58 mrem) POST (P = 0.017) (Fig. 1).

View larger version (9K): [in this window] [in a new window]   Figure 1. Mean radiation exposure for all of the members of the department of anesthesiology. The mean exposure doubled in the period after the introduction of an electrophysiology laboratory ("POST"). P = 0.017, paired Student’s t-test.

Thirty ACPs qualified for the study. There was a wide range of exposure to radiation among individual ACPs during each of the study periods (Fig. 2). The exposure was greater POST than PRE in 20 of the 30 ACPs. In another three, the exposure was unchanged POST versus PRE. Two ACPs had a 6-mo exposure in excess of 40 mrem PRE whereas 11 had a 6-mo exposure in excess of 40 mrem POST. The highest report was one individual with 178 mrem (POST).

View larger version (18K): [in this window] [in a new window]   Figure 2. Radiation exposures for each individual in the study. Two thirds of the study subjects had higher readings in the period after the introduction of the electrophysiology laboratory ("POST"). In all cases, exposures were well below recommended annual limits.

	Discussion

Top Abstract Introduction Methods Results Discussion References

 
The magnitude of radiation exposure to an ACP is a function of three variables: total radiation exposure time, distance from the source of ionizing radiation, and use of radiation shielding. The total radiation exposure time is essentially under control of the operating physician. On the other hand, the use of shielding and the distance from the source are amenable to modification by the individual ACP. Lead aprons and thyroid collars, the standard protection worn by ACP, are effective in protecting the sternum, gonads, and thyroid gland. However, a lead apron covers only 82% of the active bone marrow, so that substantial portions of marrow as well as other vulnerable sites, such as the skin and the eyes, are potentially unprotected (5,6). Lead-lined shielding screens offer more uniform protection from direct exposure but are of limited value in protection from scatter.

Distancing oneself from the source of radiation is more universally protective, with exposure inversely proportional to the square of the distance from the source. According to Mehlman and DiPasquale (7) exposure is minimal at a distance more than 36 inches. Unfortunately, anesthetizing locations are frequently cramped, limiting the ability of ACPs to adequately distance themselves from the source of radiation.

Consistent with previous reports, ACPs in this study received relatively small exposures (3,4). These doses, when annualized, are well below the occupational exposure limits (5000 mrem/year for whole body, blood-forming organs, and gonads) set by the United States Nuclear Regulatory Commission (8). However, even low levels of exposure are not inconsequential. The "stochastic" biologic effects of radiation are the consequence of direct damage to critical atoms within individual cells. The resultant cellular injuries are cumulative and permanent. There are no published data that define the lower threshold for such radiation-induced disease. The general admonition when considering occupational radiation exposure is "ALARA" (as low as reasonably achievable).

	Footnotes

 
Accepted for publication May 10, 2005.

	References

Top Abstract Introduction Methods Results Discussion References

 

1. Berrington A, Darby SC, Weiss HA, Doll R. 100 years of observation on British radiologists: mortality from cancer and other causes 1897–1997. Br J Radiol 2001;74:507–19.[Abstract/Free Full Text]
2. McGowan C, Heaton B, Stephenson RN. Occupational x-ray exposure of anaesthetists. Br J Anaesth 1996;76:868–9.[Abstract/Free Full Text]
3. Henderson KH, Lu JK, Strauss KJ, et al. Radiation exposure of anesthesiologists. J Clin Anesth 1994;6:37–41.[Web of Science][Medline]
4. Otto LK, Davidson S. Radiation exposure of Certified Registered Nurse Anesthetists during ureteroscopic procedures using fluoroscopy. AANA J 1999;67:53–8.[Medline]
5. Ellis RE. The distribution of active bone marrow in the adult. Phys Med Biol 1961;5:255–8.[Web of Science][Medline]
6. Miller ME, Davis ML, MacClean CR et al. Radiation exposure and associated risks to operating-room personnel during use of fluoroscopic guidance for selected orthopaedic surgical procedures. J Bone Joint Surg Am 1983;65:1–4.[Abstract/Free Full Text]
7. Mehlman CT, DiPasquale TG. Radiation exposure to the orthopaedic surgical team during fluoroscopy: "how far away is far enough?" J Orthop Trauma 1997;11:392–8.[Web of Science][Medline]
8. United States Department of Labor, Occupational Safety and Health Administration Standard 29 CFR 1910.1096. Ionizing radiation (general industry). Washington, DC: United States Department of Labor, Occupational Safety and Health Administration.

This article has been cited by other articles:

				L. M. Zabala, M. L. Schmitz, S. Ullah, W. B. Watkins, and V. Tuzcu Electrophysiology studies without fluoroscopy. Anesth. Analg., September 1, 2006; 103(3): 780 - 780. [Full Text] [PDF]

				J. D. Katz Electrophysiology Studies Without Fluoroscopy Anesth. Analg., September 1, 2006; 103(3): 780 - 780. [Full Text] [PDF]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Web of Science (4) Citing Articles via Google Scholar Google Scholar Articles by Katz, J. D. Search for Related Content PubMed PubMed Citation Articles by Katz, J. D. Related Collections Operating Rooms Complications Technology