Biomedical subjects

Antoinette Pechere-Bertschi

Publications and source records attributed to Antoinette Pechere-Bertschi.

4 recordsLinked to original sources

PubMed2007

Renal sodium handling in patients with normal pressure glaucoma.

Low BP (blood pressure) is a recognized risk factor for some patients with NPG (normal pressure glaucoma). We have shown previously that patients with orthostasis have impaired circadian renal handling of sodium, which may contribute to the low BP. Therefore the aim of the present study was to examine the renal handling of sodium, the circadian variations in BP and the neurohormonal response to an orthostatic test in a selected subpopulation of 18 patients with NPG with vasospastic and orthostatic symptoms, and in 24 healthy control subjects. The variations in BP and renal tubular sodium handling were evaluated using 24 h ambulatory BP recordings, 24 h urine collections and determination of endogenous lithium clearance as a marker of proximal sodium reabsorption. The neurohormonal and BP responses to changes in posture were also determined in a 30 min orthostatic test. This selected group of patients with NPG had lower 24 h ambulatory BPs (P<0.001), and a more pronounced fall in BP when assuming an upright position (P<0.001) compared with controls. FE(Li) (fractional excretion of lithium) was higher in patients with NPG than controls during the day (36.6+/-21.8 compared with 20.4+/-8.7% respectively; P<0.01; values are means+/-S.D.) as well as during the night (38.8+/-41.9 compared with 19.7+/-10.8% respectively; P<0.02), suggesting a reduced reabsorption of sodium in the proximal tubule. This was compensated for by an increased distal reabsorption of sodium in patients with NPG (P<0.01). These data demonstrate that patients with vasospastic NPG have a high excretion of lithium, suggesting reduced sodium reabsorption in the proximal tubule, in spite of a low BP. The abnormal renal sodium handling might contribute to the maintenance of arterial hypotension and progression of the optic nerve damage in these patients.

Adult↗

PubMed2007

Gonadal steroids, salt-sensitivity and renal function.

PURPOSE OF REVIEW: The aim of this article is to discuss the impact of male and female sex hormones on renal function and to develop the concept that salt-sensitivity of renal function behaves independently of the systemic blood pressure response to salt and may contribute to renal sex-specific differences. RECENT FINDINGS: Men exhibit a more rapid age-related decline in renal function than women and some renal diseases are clearly sex dependent. Recent studies have shown that gonadal steroids have an important influence on sodium handling and renal hemodynamics that may offer a key for understanding the sexual dimorphism of the renal function. It has been found that androgens increase proximal sodium reabsorption and intraglomerular pressure by modulating afferent and efferent arteriolar tonus via angiotensin II, endothelin and oxidative stress. In contrast, female sex hormones lead to a renal vasodilation and decrease filtration fraction. SUMMARY: Some newly discovered mechanisms triggering the salt-sensitivity of the renal function and the interaction between gonadal steroids and components of the renin cascade may play an important role in the dimorphism of renal response to salt.

Androgens↗

PubMed2005

Can wrist blood pressure oscillometer be used for triage in an adult emergency department?

STUDY OBJECTIVE: We compare the performance of a wrist blood pressure oscillometer with the mercury standard in the triage process of an emergency department (ED) and evaluate the impact of wrist blood pressure measurement on triage decision. METHODS: Blood pressure was successively measured with the standard mercury sphygmomanometer and with the OMRON-RX-I wrist oscillometer in a convenience sample of 2,493 adult patients presenting to the ED with non-life-threatening emergencies. Wrist and mercury measures were compared using criteria of the Association for the Advancement of Medical Instrumentation (AAMI) and the British Hypertension Society (BHS). The impact on triage decisions was evaluated by estimating the rate of changes in triage decisions attributable to blood pressure results obtained with the wrist device. RESULTS: Wrist oscillometer failed to meet the minimal requirements for recommendation by underestimating diastolic and systolic blood pressure. Mean (+/-SD) differences between mercury and wrist devices were 8.0 mm Hg (+/-14.7) for systolic and 4.2 mm Hg (+/-12.0) for diastolic measures. The cumulative percentage of blood pressure readings within 5, 10, and 15 mm Hg of the mercury standard was 32%, 58%, and 72% for systolic, and 40%, 67%, and 83% for diastolic measures, respectively. Using the wrist device would have erroneously influenced the triage decision in 7.6% of the situations. The acuity level would have been overestimated in 2.2% and underestimated in 5.4% of the triage situations. CONCLUSION: The performance of the OMRON-RX-I wrist oscillometer does not fulfill the minimum criteria of AAMI and BHS compared with mercury standard in the ED triage setting.

Adolescent↗

PubMed2004

Reasons for not intensifying antihypertensive treatment (RIAT): a primary care antihypertensive intervention study.

OBJECTIVE: Hypertension is often poorly controlled, despite its importance and despite the availability of very effective treatments. An under-recognized problem is the failure of consensus guidelines to acknowledge the important difference between efficacy in clinical trials and effectiveness in clinical practice. The present survey was designed to prospectively assess what is the target blood pressure (BP) goal defined by a general practitioner (GP) for an individual patient, and what are the reasons for not modifying an antihypertensive drug regimen, when pre-defined individual BP goals are not achieved. DESIGN: Family practice based, open intervention survey. SUBJECTS: Participating GPs enrolled 2621 hypertensive patients. At the first visit each physician was required to assess the cardiovascular risk profile of each patient and to define individual BP targets. INTERVENTIONS: Treatment was started with irbesartan alone or in fixed combination with hydrochlorothiazide. Follow-up visits were suggested after 1 month, 2 months and 4 months. Physicians were asked to report BP values under the new treatment regimen and to indicate whether in their opinion pre-defined BP targets set at baseline were achieved or not and whether the antihypertensive regimen was modified or maintained in relation to whether target BP was reached or not. MAIN OUTCOME MEASURE: To provide reasons for not changing the treatment even though BP goals were missed. RESULTS: Average target BP values defined by the physicians at baseline were 138 +/- 8 mmHg for systolic and 84 +/- 5 mmHg for diastolic BP. Among GPs, defined target BP values did not depend on individual risk stratification, but rather depended on baseline BP values. At baseline systolic and diastolic BP averaged 165/97 +/- 17/10 mmHg, while at the last visit achieved BP averaged 140/84 +/- 14/8 mmHg. There were three main reasons for not intensifying antihypertensive treatment when BP targets were not achieved. These reasons were: (1). the assumption that the time after starting the new drug was too short to appreciate its full effect (44% at first, 14% at last follow-up), (2). that there was a clear improvement or the target BP was almost reached (24% at first, 34% at last follow-up) or (3). that self-measurements were considered satisfactorily (10% at the last visit). CONCLUSIONS: Failure of physicians to follow guidelines is apparently dependent on the belief that baseline BP dictates the target, that a clear improvement in BP might be sufficient and that the full drug effect may take up to 4 months or more to be attained.

Aged↗