Stress Testing in the Medical Evaluation for Hazardous Materials Duty: Results and Consequences in Three Groups of Candidates

Abstract

GXT identified marked hypertension in 12 HAZMAT candidates and ischemic ST changes in 10, the latter appearing to be false-positives. Other testing yielded useful baselines, rarely disqualifying.

Physiologic Strain during Treadmill Electrocardiography in the Medical Evaluation of Candidates for Hazardous Materials Duty, with and without Added Heat Stress

“…In summary, the limitation of the SBT in causing thermal stress was confirmed in a 203 examinees for hazmat duty, and a novel variation which might be termed a Hot Bruce Test (HBT) is described and shown to induce higher TT [39] and PSI values, both similar to those found in hazmat response simulations [40]. The HBT does not require more expensive equipment or longer testing time than the SBT, and may have added value in the medical evaluation of candidates for hazmat duty [41,42].…”

A Thermal Stress Treadmill Walk for Clinic Evaluation of Candidates for Hazardous Materials (HazMat) Duty

“…· clothing: in addition to the gym shorts and T-shirts usually worn for stress tests, an impervious vinyl "sauna suit" (athletic works vinyl conditioning suit, WalMart Stores, USA) was worn during the TSTW; · duration and intensity: whereas typical stress testing of hazmat workers involves 10-18 min of increasing treadmill speed and grade [12], the TSTW employed a constant 5% grade and speed chosen to approximate maximal walking velocity (6 km/h, 3.7 mph) aiming to complete 30 min, after which grade was increased to 10% for an additional 15 min. Each subject wore a 2.65-kg (5-lb) weight on each wrist and ankle during TSTW, simulating tools, first aid and other emergency equipment.…”

“…The perceived exertion was also recorded during TSTW, using the Borg index: 6 = nil, 11 = light, 13 = somewhat hard, 15 = very hard, 20 = maximum tolerable [17]. The Borg scale (6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) was displayed on the wall facing the exercising subject so that it was visible at all times, and the subject could readily respond with a numerical value when asked at 10-min intervals. Since only the physician and nurse were present during the one-subject BPTE and later TSTW, the Young index and Borg scale responses remained confidential.…”

“…Potential heat stress forms the basis for U.S. federal recommendations that stress testing be considered in evaluations for such duty, but the stress test employed does not incorporate thermal stress. Specifically, our preliminary observations of Bruce protocol testing found that tympanic temperature (TT) increased only 0.4 °C (SD 0.6) [12,13] compared to increases of 0.9 °C (SD 0.3) during simulated hazmat responses [3,4,5]. The aim of the present study, therefore, was to test the hypothesis that treadmill exercise in a medical clinic can create physiological strain similar to that imposed by hazmat incidents.…”