Is nurse-measured blood pressure a valid substitute for ambulatory blood pressure monitoring?

BACKGROUND: Because ambulatory blood pressure monitoring (ABPM) is not available everywhere, the objective of the study was to determine whether nurse-measured blood pressure could be an acceptable substitute to ABPM. METHODS: We analyzed the data of 2385 consecutive patients referred to our hypertension clinic for the performance of ABPM. Before ambulatory monitoring was performed, a nurse-measured BP was obtained three times using a Y-tube connecting the sphygmomanometer and the recorder. We compared the mean value of the three nurse-measured blood pressures with that of the 12h daytime ambulatory monitoring, considered as the reference. RESULTS: The difference between the nurse-measured and the ambulatory blood pressure was small but statistically significant, indicating that nurse-measured blood pressure tends to overestimate both diastolic and systolic blood pressure. The difference between the nurse blood pressure and ABPM was greater among treated hypertensive patients than untreated patients. To diagnose hypertension, defined as a blood pressure of over 140/90mmHg by ABPM, the positive predictive value of the nurse blood pressure was 0.81 and the negative predictive value 0.63. However, these predictive values could be improved with less stringent cut-off values of blood pressure. Thus, for a diastolic blood pressure above 100mmHg, the positive predictive value of nurse blood pressure was 0.55 and the negative predictive value 0.91. These figures were relatively similar for previously treated and untreated patients. CONCLUSION: Nurse blood pressure is less accurate than ABPM in diagnosing hypertension, defined as a blood pressure of over 140/90mmHg. It could, however, be an acceptable substitute, especially to exclude people who do not need to be treated, in situations where lower resources require a less rigorous definition of hypertension.

Effects of SR 49059, a new orally active and specific vasopressin V1 receptor antagonist, on vasopressin-induced vasoconstriction in humans.

We have evaluated the efficacy of SR 49059, a new orally active and specific vasopressin V1 receptor antagonist (arginine-vasopressin [AVP]), in the blockade of the vascular effects of exogenous AVP in healthy subjects. In preliminary experiments, two procedures to measure the V1 vascular effects of AVP were assessed. First, the AVP-induced changes in skin blood flow were investigated by the injection of increasing doses of AVP intradermally, with or without a previous local vasodilation with calcitonin gene-related peptide (CGRP). In a second protocol, AVP was infused intra-arterially, and the changes in radial artery diameter and blood flow were measured. The intradermal injection of AVP caused significant decreases in skin blood flow, and the use of CGRP increased the sensitivity of the method by a factor of 10(2) to 10(3). AVP infused intra-arterially caused dose-dependent decreases in the radial artery diameter and blood flow. In the main study, the potency and efficacy of SR 49059 to block the AVP-induced changes in skin blood flow were assessed in 12 healthy men with a double-blind, triple crossover study design. The subjects were randomized to receive a placebo orally and 30 mg and 300 mg of the antagonist at a 1-week interval. The subjects were then further randomized to evaluate the efficacy of the same doses of the antagonist to block the vasoconstriction of the radial artery induced by an intra-arterial infusion of AVP. SR 49059 inhibits, dose-dependently and significantly, the AVP-induced changes in skin blood flow, with a peak effect occurring between 2 and 6 hours after injection. In addition, the 300-mg dose of SR 49059 completely blocked the vasoconstriction of the radial artery induced by AVP. In conclusion, skin blood-flow measurement, after intradermal injection of AVP on a skin area vasodilated with CGRP, is an effective method to investigate the V1 vascular effect of AVP in humans. SR 49059 is a potent and specific antagonist of V1 receptors, which blocks the AVP-induced vasoconstriction.

[Differentiation between glomerular and non-glomerular erythrocyturia: what is the value of differential microhematuria diagnosis?]. / Différentiation entre érythrocyturie glomérulaire et non-glomérulaire: quelle utilité pour le diagnostic différentiel des microhématuries?

A few years ago, a new and simple method has been proposed to help guiding the investigation of microhematuria. This method which consists in quantifying the percentage of deformed polymorphous erythrocytes in the urinary sediment using phase contrast microscopy allows to distinguish glomerular from non-glomerular erythrocytes. In this paper, we have reviewed the recent literature concerning this approach and have discussed the conclusions according to our own experience based on the analysis of 147 patients presenting with microhematuria. Our results demonstrate that this technique is still limited by the difficulty to obtain well-defined cut-off values which effectively differentiate renal from urologic diseases. Thus, only extreme results showing either the total absence or the presence of a very high percentage of dismorphic erythrocytes appear to be helpful for the physician. Despite the introduction of this new method, many patients with microhematuria are insufficiently investigated.

[Hemorheologic changes in patients with essential hypertension treated with prazosin]. / Hemoreoloske promjene kod pacijenata sa esencijalnom hipertenzijom tretiranih prazosinom.

Prazosin which is a selective alfa-1 blocking drug has a very good antihypertensive effect. Its hemorheological effects were studied in 20 patients with essential hypertension (I and II degree according to WHO classification). After 6 weeks of the therapy with prazosin, hematocrit and viscosity of the whole blood and plasma were significantly reduced, because of hemodilution, while aggregability of erythrocyte and "Tk" values were not significantly reduced. Platelet aggregation induced by collagen, ADP and adrenaline, showed a decrease after the treatment. Assuming the hemorheological effects not to be crucial in choosing an antihypertensive agent, we must not, however, neglect them, especially in patients with compromised hemorheological profile, and we should take advantage of the positive hemorheological effect of prazosin, particularly in a long antihypertensive treatment.

[Factors which affect patient cooperation in the therapy of hypertension]. / Faktori koji uticu na saradnju pacijenta u terapiji kod hipertenzije.

The socio-demographic factors (sex, age, social status and professional qualification), side effects of antihypertensive drugs and the therapeutic effects were compared with patient compliance in a group of 387 hypertensive patients. The results showed that the sociodemographic factors and presence of side effects had no significant influence upon patient compliance. Unlike these factors, therapeutic effects had a significant impact upon patient compliance.

[The beneficial and harmful interactions of antihypertensive drugs]. / O nekim korisnim i nekorisnim interakcijama antihipertenzivnih lijekova.

Drug interaction has been a very important and serious aspect of the modern management of hypertension. The constantly rising number of antihypertensive drugs has been contributing to the number of pharmacological interactions during antihypertensive treatment. Some of the interactions are very helpful and favourable leading to the synergistic effects of the drugs, while others are undesirable and useless, diminishing the antihypertensive effects of individual drugs, or transforming the effects and causing serious and harmful side effects. If a patient, suffering from hypertension, is treated for another associated disease, the number of interactions is increasing. If the nature of the interactions is not know and if they are ignored, the treatment can be more harmful then beneficial.