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Biomedical subjects

J Rawles

Publications and source records attributed to J Rawles.

44 records · Page 3Linked to original sources

Evaluation of a long acting formulation of nicardipine in hypertension by clinic and home recorded blood pressures and Doppler aortovelography.

1. A novel formulation of nicardipine (50% standard (short acting), 50% sustained release) was evaluated in mild hypertension in a double-blind, randomized, placebo-controlled study, using clinic measurements (Hawksley) augmented by home recorded blood pressures (Copal UA 251). 2. Nicardipine 60 mg twice daily for 28 days produced a highly significant reduction in sitting blood pressure compared with placebo both pre dose (mean difference 17/8 mm Hg) and 2 h post dose (mean difference 34/26 mm Hg). 3. Home recordings confirmed the hypotensive effect and also revealed a consistent 'peak' effect between 2-4 h after dosing (mean difference 32/22) mm Hg). 4. Doppler aortovelography at 2 h post-dose showed a significant increase in in stroke and minute distance (linear analogues of stroke volume and cardiac output respectively) compared with placebo. The increase in stroke distance was linearly related to change in plasma concentration of nicardipine. 5. Of the 14 patients enrolled in the study, nine experienced troublesome adverse effects on nicardipine (headaches, facial flushing, palpitations, ankle oedema) and two of these were unable to complete the study as a result. 6. This formulation of nicardipine, in the fixed dosage used in this study, is characterized by an effective antihypertensive action but also by an unacceptable adverse effect profile, presumably due to an excess of its 'short acting' component.

Blood Pressure↗

Castigating QALYs.

The ethical problem of how to apportion limited resources amongst the needy has been forced on us by arbitrary limitation of health expenditure. Its solution would not be required if health expenditure were higher. Distribution of resources according to best value for money, assessed as Quality Adjusted Life Years (QALYs) per unit cost, has been suggested as a possible solution, but leads to absurd anomalies. In the calculation of QALYs the implied value of life is no more than the absence of suffering. The use of QALYs for the comparison of treatments that are symptomatic or life-saving therefore leads to serious undervaluation of life and treatments that prolong it. Moreover, distribution of resources by best value for money, however assessed, is inequitable since for a given degree of suffering those whose illnesses happen to be cheaper to treat will be treated in preference to those whose treatments are more expensive.

Economics↗

Cardiac output in twin pregnancy.

No significant difference has been found in either stroke volume or cardiac output between twin pregnancies and singleton pregnancies. Cardiac output is less in preeclamptic twin pregnancies.

Blood Pressure↗

A simple, non-invasive method of assessing the acute hemodynamic effects of doxorubicin.

Left ventricular stroke distance was measured by Doppler ultrasound in 10 doxorubicin-treated and 10 control patients. Measurements were made 10 min, 2 h and 4 h after drug administration. Stroke distance (a linear analogue of stroke volume) increased significantly from 12.6 cm (S.D. 2.7) before and 12.5 cm (S.D. 2.7) 10 min after, to 13.6 cm (S.D. 2.8) 2 h after and 13.7 cm (S.D. 2.7) 4 h after doxorubicin (p less than 0.05). Throughout the study period there were no significant changes in stroke distance in the control patients who were infused with similar fluid volumes, and no significant changes in heart rate or blood pressure in either group. These observations confirm previous findings made by radionuclide ventriculography, a much more complex, expensive and hazardous technique, not amenable to repetition at short time intervals. The measurement of stroke distance by Doppler ultrasound is a convenient bedside method of assessing acute hemodynamic changes after doxorubicin or any drug affecting cardiac function. The method we describe is eminently suitable for investigating the cardiotoxicity of chemotherapeutic agents.

Adult↗