Seventy-nine patients were enrolled in this study from September 2003 to June 2005 as a convenience sample. Nine patients were excluded from the analysis as they failed to meet study asthma criteria following post hoc inspection of both outpatient and inpatient records. Of the remaining 70 patients, 19 (27.1%) were admitted to the hospital from […]
PP was induced in a healthy adult using an established technique by having him breathe through a fixed resistance connected to a two-way nonrebreathing valve (Hans Rudolph; Kansas City, MO) that was attached to a manometer (OEM Medical; Marshalltown, IA). Airflow resistance occurred during inspiration, whereas expiration was unimpeded. The reference subject’s BP and oximetry […]
The cost of appropriate outpatient care was determined in the same way based on one ED visit without patient relapse, which was defined as an unscheduled medical office or ED visit within 72 h of hospital discharge. The cost of inappropriate inpatient care was based on the average cost in 2004 for conditions denoted by […]
All variable distributions were assessed for violation of the assumption of normality based on skewness, the Shapiro-Wilk statistic (a = 0.01), and visualization. Variables having a significant deviation from normal via the Shapiro-Wilk statistic were submitted to the following three linear transformations: square root; natural logarithm; and inverse. The linear transformation that improved the distribution […]
Continuous BP measurements were obtained noninvasively with a wrist mounted arterial tonometer (NCAT; Nellcor; Pleasanton, CA). The analog output of this device was digitized via an eight-bit analog-to-digital converter (DAQ-500; National Instruments; Austin, TX) [Fig 1]. The sampling rate was 200 Hz. A peak-seeking periodic amplitude analysis algorithm was designed (LabVIEW; National Instruments) that would […]
Patients and Protocol: Adult patients who were 18 to 70 years of age, had a documented history of asthma, and were presenting with shortness of breath and probable asthma exacerbation were approached for study enrollment by trained clinical research assistants. Informed consent was obtained during the ED triage process or shortly thereafter, before ED treatment […]
Pulsus paradoxus (PP) is a pathophysiologic vital sign that historically has been a cornerstone in the evaluation of patients with acute asthma.2, However, the measurement of PP is rarely performed, and the accuracy of its measurement via sphygmo-manometry is questionable. Despite this, PP has been used in a number of asthma studies and continues to […]