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Biomedical subjects

M Lafay

Publications and source records attributed to M Lafay.

8 recordsLinked to original sources

Detection of pulmonary hypertension by Doppler echocardiography of the inferior vena cava in chronic airflow obstruction.

Pulsed Doppler echocardiography of the inferior vena cava is an accurate method for the diagnosis of tricuspid regurgitation and impaired right ventricular compliance, two features of pulmonary hypertension. The purpose of this study was to assess the value of Doppler echocardiography of the inferior vena cava for the detection of pulmonary arterial hypertension in patients with chronic obstructive lung disease. Pulse Doppler echocardiography of the inferior vena cava and right heart catheterisation were performed in 29 patients with severe chronic obstructive lung disease. The mean pulmonary arterial pressure was 27 (10) mm Hg for the entire group; 62% of patients (18/29) had pulmonary arterial hypertension (mean pulmonary arterial pressure greater than 20 mm Hg). An adequate Doppler signal could be obtained in 25 of the 29 patients (86%). Pulsed Doppler echocardiography of the inferior vena cava gave normal results in 10 patients and disclosed tricuspid regurgitation in seven patients, impaired right ventricular compliance in seven patients, and both of these abnormalities in one patient. An abnormal Doppler echocardiogram of the inferior vena cava (tricuspid regurgitation or impaired right ventricular compliance, or both) predicted the presence of pulmonary arterial hypertension with a sensitivity of 87% and a specificity of 80%. These results suggest that pulsed Doppler echocardiography of the inferior vena cava may be a useful though imperfect method of detecting pulmonary arterial hypertension in patients with chronic obstructive lung disease.

Echocardiography, Doppler

Noninvasive estimation of systolic pulmonary artery pressure using Doppler echocardiography in patients with chronic obstructive pulmonary disease.

In patients with acquired or congenital heart diseases, the systolic pulmonary artery pressure (PAPs) can be predicted using continuous-wave Doppler ultrasound (CWD) measurement of the peak velocity of a tricuspid regurgitation (TR) jet. The aim of this study was to determine whether CWD could be used to accurately estimate PAP in patients with chronic obstructive pulmonary disease (COPD). In 41 patients with stable COPD, we prospectively performed CWD and right heart catheterization. The mean value of PAPs for the entire group was 38.5 +/- 14.9 mm Hg. Pulmonary arterial hypertension (PAPs greater than or equal to 35 mm Hg) occurred in 51 percent (21/41) of patients. Doppler estimation of PAP was impossible in 34 percent (14/41) because of poor signal quality (n = 3), absence of Doppler-detected TR (n = 8), and inadequate TR Doppler signal (n = 3). The PAP could be estimated in 66 percent (27/41) of patients. A statistically significant correlation was found between the Doppler-estimated PAP and the catheter-measured PAPs (r = 0.65; p less than 0.001; SEE = 9 mm Hg). Therefore, CWD appears to be useful for the noninvasive estimation of PAP in patients with COPD. However, this method is associated with two limitations: (1) the high percentage of patients in whom the PAP cannot be estimated by CWD, mainly because of the absence of Doppler-detected TR, and (2) the high value of the standard error of the estimate. The combination of CWD with other Doppler methods should increase the feasibility and accuracy of Doppler echography for the prediction of PAP in patients with COPD.

Aged

[Total serum IgE: normal pediatric values using the FAST IgE fluoroimmunoenzymatic technic].

This reports covers the application to paediatrics of total IgE determination by the means of a new direct, sandwich type, fluorescence enzyme immuno-assay (Fluoro-allergo sorbent test:FAST IgE). The technical process is adapted for usual determinations, in case of infants and young children, of low normal rates with a good sensitivity, and of high pathological rates. IgE total usual values are established by the FAST IgE test from serums of healthy children, aged from one day to 14 years. Seven age groups are to be distinguished.

Adolescent

Hepatic plasma flow during sodium nitroprusside-induced hypotension in humans.

Changes in hepatic plasma flow (HPF) during sodium nitroprusside (SNP) induced hypotension were studied in 14 patients undergoing intracranial aneurysm surgery under neurolept anesthesia. Patients were monitored with the use of a radial artery catheter and a thermistor-tipped Swan-Ganz catheter. Hypotension was induced with incremental increases in the rate of SNP infusion until a stable mean arterial pressure (MAP) 35-55 mmHg had been achieved. In one group (Group A) of 10 patients, indocyanine green (ICG) clearance was determined simultaneously with hemodynamic variables, before and during SNP hypotension. In a second group (Group B) of four patients, a catheter was inserted into a hepatic vein to determine the ICG hepatic extraction (HE) coefficient. In Group A, MAP decreased from 73 +/- 10 (SD) to 41 +/- 9 mmHg, while cardiac index (CI) decreased in six patients and increased in four patients. However, the mean value of CI did not change significantly. The mean value of ICG clearance was not significantly affected by SNP hypotension. Nevertheless, a positive linear correlation existed between individual variation in CI and ICG clearance (r = 0.96). On the other hand, no correlation was noted between the change in MAP and ICG clearance. In Group B patients, the ICG HE coefficient remained unchanged during SNP hypotension, suggesting that ICG clearance varies only according to the variation in HPF. In conclusion, this study demonstrated that HPF did not decrease, despite a range of 20-60% decrease in blood pressure when CI is maintained during SNP hypotension.

Adult