James F. Schauble

Prevalence of latex allergy among anesthesiologists : Identification of sensitized but asymptomatic individuals

Background Occupational exposure to natural rubber latex has led to sensitization of health‐care workers. However, the prevalence of latex allergy among occupationally exposed workers in American hospitals has not been reproducibly determined. The objectives of the current study were to determine the prevalence of and risk factors for latex sensitization among a cohort of highly exposed health‐care workers. Methods Participants were 168 of 171 eligible anesthesiologists and nurse anesthetists working in the Department of Anesthesiology and Critical Care Medicine. A clinical questionnaire was administered, and testing was performed using a characterized nonammoniated latex reagent for puncture skin testing, a Food and Drug Administration‐approved assay to quantify latex‐specific immunoglobulin E antibody in serum, and, when required for clarification, a validated two‐stage (contact‐inhalation) latex glove provocation procedure. Results The prevalence of latex allergy with clinical symptoms and latex sensitization without clinical symptoms was 2.4% and 10.1%, respectively. The prevalence of irritant or contact dermatitis was 24%. The risk factors identified for latex sensitization were atopy (odds ratio, 14.1; 95% CI, 1.8–112.1; P = 0.012); history of allergy to selected fruits, such as bananas, avocados, or kiwis (odds ratio, 9.8; 95% CI, 1.6–61.9; P = 0.015); and history of skin symptoms with latex glove use (odds ratio, 4.6; 95% CI, 1.6–13.4; P = 0.006). Conclusions The prevalence of latex sensitization among anesthesiologists is high (12.5%). Of these, 10.1% had occult (asymptomatic) latex allergy. Hospital employees may be sensitized to latex even in the absence of perceived latex allergy symptoms. These data support the need to transform the health‐care environment into a latex‐safe one that minimizes latex exposure to patients and hospital staff.

Limitations of thermodilution ejection fraction: Degradation of frequency response by catheter mounting of fast-response thermistors

The present study examined whether catheter-mounting of a fast-response thermistor impaired the thermistors ability to measure rapid temperature changes during thermodilution measurement of ejection fraction (EF). The response to a square-wave temperature change of six fast-response thermistors mounted on commercially available, pulmonary artery balloon-flotation catheters was compared to the response of a similar but unmounted fast-response thermistor. The response of the catheter-mounted fast-response thermistors recorded only 82% to 92% of a step-temperature change at 0.5 sec, and 88% to 96% of the step change at 1.0 sec. In contrast, the unmounted fast-response thermistor responded to 100% of the step change in 125 msec. The response of the catheter-mounted fast-response thermistors demonstrated an important slow component (second time constant) introduced by the catheter body, so that equilibration to a temperature change was not complete for about 6 sec. This slow equilibration lowered EF measured by thermodilution below true EF.