Clinical Investigation
1. Physiologic Effects of the TASER After Exercise
Gary M. Vilke, MD, Christian M. Sloane, MD, Amanda Suffecool, Fred W. Kolkhorst, PhD,
Tom S. Neuman, MD, Edward M. Castillo, PhD, MPH, and Theodore C. Chan, MD
From the Department of Emergency Medicine, University of California, San Diego Medical
Center (GMV, CMS, TSN, EMC, TCC), San Diego, CA; and the School of Exercise and
Nutritional Sciences, San Diego State University (AS, FWK), San Diego, CA.
Address for correspondence and reprints: Gary M. Vilke, MD; e-mail: gmvilke@ucsd.edu.

Work containing preliminary data from this study has been presented as a poster presentation at
the Society for Academic Emergency Medicine (SAEM) Annual Meeting, Washington, DC,
May 2008.

This study was funded by the National Institute of Justice (2005-IJ-CX-K051).

A related commentary appears on page 771.
Copyright © 2009 Society for Academic Emergency Medicine
KEYWORDS
conductive energy devices • police • cardiac • physical restraint
ACADEMIC EMERGENCY MEDICINE 2009; 16:704–710 © 2009 by the Society for
Academic Emergency Medicine

ABSTRACT
Objectives: Incidents of sudden death following TASER exposure are poorly studied, and
substantive links between TASER exposure and sudden death are minimal. The authors studied
the effects of a single TASER exposure on markers of physiologic stress in humans.
Methods: This prospective, controlled study evaluated the effects of a TASER exposure on
healthy police volunteers after vigorous exercise, compared to a subsequent, identical exercise
session that was not followed by TASER exposure. Subjects exercised to 85% of predicted heart
rate (HR) on an ergometer and then were given a standard 5-second TASER activation.
Measures before and for 60 minutes after the TASER activation included minute ventilation,
tidal volume, respiratory rate, end-tidal pCO2, oxygen saturation, HR, blood pressure (systolic
BP/diastolic BP), 12-lead electrocardiogram, and arterialized blood for pH, pO2, pCO2, and

lactate. Each subject repeated the exercise and data collection session on a subsequent data,
without TASER activation. Data were analyzed using paired Student's t-tests with differences
and 95% confidence intervals (CIs). Statistical significance was adjusted for multiple
comparisons.
Results: A total of 25 officers (21 men and 4 women) completed both portions of the study. After
adjusting for multiple comparisons, the TASER group was significantly higher for systolic BP at
baseline (difference of 14.1, 95% CI = 8.7 to 19.5, p < 0.001) and HR at 5, 30, and 60 minutes
with the largest difference at 30 minutes (difference of 7.0, 95% CI = 2.5 to 11.5, p = 0.004).
There were no other significant differences between the two groups in any other measure at any
time.
Conclusions: A 5-second exposure of a TASER following vigorous exercise to healthy law
enforcement personnel does not result in clinically significant changes in ventilatory or blood
parameters of physiologic stress.

Received January 23, 2009; revision received March 27, 2009; accepted April 12, 2009.