Biomedical subjects

K Chetty

Publications and source records attributed to K Chetty.

4 recordsLinked to original sources

PubMed1979

Effects of isosorbide dinitrate on pulmonary hypertension in chronic obstructive pulmonary disease.

Eighteen patients with chronic obstructive pulmonary disease with pulmonary hypertension were studied to assess the hemodynamic response to acute oxygen administration and to oral isosorbide dinitrate (ISDN). All 18 patients had baseline hemodynamic measurements and hemodynamic measurements during low-flow nasal oxygen. Following a second baseline measurement, patients received either oral ISDN (11 patients) or placebo (7 patients) in a randomized, double-blind protocol. Heart rate decreased with oxygen administration but there were no other significant hemodynamic changes. With oral ISDN, there was a significant fall in pulmonary artery and brachial artery pressure. Cardiac output, right atrial pressure, pulmonary wedge pressure, and pulmonary vascular resistance all fell but not significantly. We conclude that oral ISDN is effective in reducing pulmonary hypertension in patients with chronic obstructive pulmonary disease.

Blood Pressure↗

PubMed1979

P pulmonale in status asthmaticus.

We studied 129 patients during acute, severe asthmatic attacks. Electrocardiograms showed P pulmonale in 49% of patients who had an arterial carbon dioxide tension (PaCo2) greater than or equal to 45 mm Hg and an arterial pH less than or equal to 7.37, whereas P pulmonale was present in only 2.5% of asthmatics who had a PaCO2 less than or equal to 44 mm Hg and a pH greater than or equal to 7.38 (p less than 0.001). P wave and QRS axes were 79 +/- 8 degrees and 80 +/- 20 degrees, respectively, in the presence of P pulmonale. When P pulmonale disappeared, the P wave and QRS axes shifted significantly to the left (p less than 0.001). Electrocardiographic P pulmonale persisted 12 to 60 hr after correction of hypoxemia, hypercapnia, and acidosis. In 7 patients with P pulmonale and respiratory acidosis, cardiac catheterization demonstrated normal artery pressures (PAPs) measured relative to atmospheric pressure. In 12 of these peak inspiratory pulmonary artery transmural pressures (PATPs) were increased. Since increased right heart transumural pressures could result in chamber distention, these data are consistent with the hypothesis that reversible P pulmonale in status asthmaticus is explainable on the basis of markedly negative tidal pleural pressures and increased right heart transmural pressures.

Adolescent↗

PubMedDate not supplied

Comparison of noninvasive with hemodynamic data in patients with pulmonary hypertension due to chronic obstructive pulmonary disease.

Twenty-one patients with chronic obstructive pulmonary disease were studied with right heart catheterization. The mean pulmonary artery pressure (PAP) was compared with several noninvasive tests. The pulmonary lobar diameter/thoracic ratio correlated with the PAP, r = 0.677, P less than 0.01. The oxygen saturation and pH were used to derive a calculated value for PAP. The calculated PAP correlated with PAP values measured below 40 mm Hg, r = 0.787, P less than 0.01 but correlated very poorly with PAP values measured above 40 mm Hg. The electrocardiogram revealed at least one criterion for right ventricular abnormality in all 18 patients with pulmonary hypertension, but was too nonspecific to correlate with PAP. The hemoglobin concentration did not correlate with PAP. There was such wide variation between the measured PAP and the various noninvasive tests that these noninvasive tests could not be used to accurately predict the PAP in an individual patient.

Blood Gas Analysis↗

PubMedDate not supplied

The effect of salicylate infusion on the alveolar epithelial membrane in the isolated perfused lung.

We observed two patients with aspirin (ASA) ingestion (blood levels of 87 and 56.5 mg/100 ml) who presented with noncardiogenic pulmonary edema (adult respiratory distress syndrome. To determine if ASA had a direct effect on the alveolar epithelial membrane, we established an in vitro isolated lung model and perfused it with platelet free plasma. T1/2 (in minutes), the time for 50% equilibration between the plasma and the saline filled lung, was determined before and after 500 mg salicylate infusion for various molecular weight dextrans. T1/2 decreased significantly (p less than 0.05) as follows: 3000 MW dextran, 2273 +/- 932 to 961 +/- 375; 40,000 MW dextran, 4059 +/- 1550 to 733 +/- 275; 70,000 MW dextran, 11,730 +/- 2750 to 7700 +/- 2230. Histamine levels in plasma and lung liquid did not change significantly with ASA infusion. We conclude that ASA directly increases alveolar epithelial permeability to dextrans less than 70,000 MW.

Aged↗