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At least 901 records · Page 50Linked to original sources
PubMed1993

Aeroallergen-induced dyspnea in freely moving guinea pigs: quantitative measurement by bias flow ventilated whole body plethysmography.

Guinea pigs were sensitized and boostered with i.p. injections of ovalbumin (OA) 10 micrograms + Al(OH)3 100 mg. Thirteen days after the last injection animals (800-1100 g) were placed in bias flow ventilated whole body plethysmographs and allowed to stabilize for 2 h. Lung function was recorded for up to 2 h before and 5 h after aeroallergen challenge (OA 20 mg/ml, 60 s, 20 psi) by a noninvasive pulmonary analyzer for unrestrained rodents. Aeroallergen challenge produced immediate dyspnea and gasping (peaking between 8 and 17 min). Gasping was associated with an increase in amplitude in the box pressure fluctuations (93%), and in the slope of the fluctuations (391%). Respiratory rate increased (103 to 175 breaths/min, 78%), the product of breathing rate times box pressure amplitude increased (161 to 432, 180%). Relaxation time (the time it takes the box pressure signal to drop from its peak to 1/3 of its peak value) declined (0.16 to 0.05 s, 72%). All of these lung dysfunction changes were highly significant (p < 0.001). Lung dysfunction persisted for 60 to 120 min after challenge. One of 8 animals tested died within 10 min. None of the animals exhibited late asthmatic responses during the 5 h post-challenge period. Based on these data we conclude that this technique allows quantitative analysis of dyspnea, gasping, and an abnormal pattern (waveform) of breathing.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1982

Central blood pooling as an explanation for lowered FRC during anaesthesia? Thigh volume measurements by plethysmography.

Segmental volumes of the thigh and the upper arm were measured by means of an air-filled plethysmograph before and during various anaesthesias. A small but significant fall in segmental volume was seen with the induction of anaesthesia with thiopentone. A further fall was observed during neurolept anaesthesia but not with halothane. Epidural and spinal anaesthesias caused no change in segmental thigh volume. The results suggest a redistribution of 50-150 ml blood from the extremities to the trunk during general anaesthesia. This redistribution may contribute to the well-known fall in FRC with general anaesthesia.

Abdomen↗
PubMed1992

Ambulatory strain-gauge plethysmography and blood volume scintimetry for quantitative assessment of venous insufficiency.

In the present study, a strain-guage plethysmographic method (ASGP) is compared to an isotope plethysmographic method (ABVS), in order to evaluate how an externally recorded volume change corresponds to blood displacement within the leg during exercise. The coefficient of correlation for RT (venous return time) was 0.67 (P less than 0.001) and for EV (expelled volume) it was 0.61 (P less than 0.001). The RT values were similar by the two methods both in healthy controls and in patients with Chronic Venous Insufficiency (CVI). The corresponding EV values showed the same pattern in controls and patients but the values differed substantially. By ASGP the value was approximately 2 ml per 100 ml tissue compared to 33 ml per 100 ml blood by the ABVS method. Both methods could clearly distinguish normal controls from patients with chronic deep venous insufficiency, but ABVS could only make this distinction when the ankle area of measurement was applied.

Adult↗
PubMed2000

Comparison of air-displacement plethysmography, hydrodensitometry, and dual X-ray absorptiometry for assessing body composition of children 10 to 18 years of age.

Body density (Db) of 54 boys and girls 10-18 years of age (13.9 +/- 2.4 years) was measured in an air-displacement plethysmograph, the BOD POD, and compared to Db determined by hydrodensitometry (HW). Both Db values were converted to percent body fat (%BF) using a two-component model conversion formula and compared to %BF determined by dual energy X-ray absorptiometry (DXA). Body density estimated from the BOD POD (1.04657 +/- 0.01825 g/cc) was significantly higher than that estimated from HW (1.04032 +/- 0.01872 g/cc). The relative body fat calculated from the BOD POD (23.12 +/- 8.39 %BF) was highly correlated but, on average, 2.9% BF lower than %BF DXA. Average %BF estimates from HW and DXA were not significantly different. Despite consistently underestimating the %BF of children, the strong relationship between DXA and the BOD POD suggests that further investigation may improve the accuracy of the BOD POD for assessing body composition in children.

Absorptiometry, Photon↗