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CARDIOVASCULAR
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Volume 4, 1999, No 1 |
The Effect of Phentolamine on Pulmonary
Hemodynamics Evaluated by Doppler Echocardiography in Infants
with Severe Bronchopneumonia
D. Junbao, Z. Heping, Z. Bin, J. Jianfeng, S. Lian, L. Yuan
Background: In our foregoing studies, we found that pulmonary hypertension may occur in infants with severe bronchopneumonia mainly because of hypoxemia and pulmonary hypertension can further affect the cardiac function and gas exchange through the lungs. Thus, reversing pulmonary hypertension is important in the management of those with severe broncho-pneumonia besides the conventional therapy. Phentolamine, an alpha-adrenoceptor blocking agent, is one of the drugs commonly used for treating pulmonary hypertension in severe cases of pneumonia in infants and children. But little has been known about the impact of phentolamine on pulmonary hemodynamics in such cases. Nowadays, Doppler echocardiography has made it possible to assess pulmonary artery pressure noninvasively. The aim of this study was to examine the effect of phentolamine on pulmonary hemodynamics in severe cases of broncho-pneumonia.
Methods: The authors measured the ratios of right ventricular pre-ejection period to right ventricular ejection time (RPEP/ RVET) and right ventricular pre-ejection period to acceleration time (RPEP/ AT) by Doppler echocardiography and other indices of pulmonary hemodynamics in 27 infants, of whom 10 suffered from severe broncho-pneumonia and 17 were normal controls. The study was performed before and after the phentolamine treatment.
Results: The results showed that both ratios were much greater in the acute stage of severe broncho-pneumonia than in normal controls (RPEP/RVET, 0.382 ± 0.051 vs. 0.288 ± 0.035; RPEP/AT, 1.303 ± 0.300 vs. 0.899 ± 0.175, all p < 0.01, respectively ). However, they were significantly reduced after 10 minutes of phentolamine administration compared with those at baseline (RPEP/RVET, 0.276 ± 0.037 vs. 0.382 ± 0.051; RPEP/AT, 0.782 ± 0.183 vs. 1.303 ± 0.300, all P < 0.01, respectively), suggesting that elevated pulmonary artery pressure was promptly reduced [calculated pulmonary artery mean pressure, 33.4 mmHg (4.4 kPa) at baseline vs. 15.9 mmHg (2.1 kPa) after 10 minutes of phentolamine administration].
Conclusion: The results of this study indicated that phentolamine played an important role in attenuating pulmonary hypertension and Doppler echocardiography was of great value in evaluating the effect of phentolarnine on pulmonary hemodynamics in severe broncho-pneumonia of infants.
Key words: phentolamine, Doppler, pulmonary, broncho-pneumonia
Address for Correspondence:
Prof. D. Junbao
Department of Pediatrics
First Hospital of Beijing Medical University
Si-An Men Street, No. 1
Beijing 100034
P. R. China
Reference:
(CVE. 1999; 4 (1): 11-14)
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