A subnormal plasma volume in formerly preeclamptic women is associated with a low venous capacitance.

Contains fulltext : 48810.pdf (publisher's version ) (Open Access)OBJECTIVE: Pregnancy induces a smaller rise in plasma volume in formerly preeclamptic women with a pre-existent subnormal plasma volume than in their counterparts with a normal plasma volume. These women also have a three times higher recurrence rate of pregnancy-induced hypertensive disorders. In this study we tested the hypothesis that a subnormal plasma volume in these women is related to a lower capacitance of their venous compartment. METHODS: In 31 nonpregnant formerly preeclamptic women with a subnormal plasma volume and eight parous controls, we infused intravenously 500 mL of a modified gelatin solution over 30 minutes. Before and after infusion we measured the circulating levels of alpha-atrial natriuretic peptide (alpha-ANP) and active plasma renin concentration (APRC). During volume loading, we recorded the change in heart rate, stroke volume, and cardiac output using pulse contour analysis. We measured the ratio of percent change in blood volume and percent change in cardiac output during volume loading as a marker for venous capacitance. RESULTS: During volume loading, patients differed from controls by a larger rise in alpha-ANP, pulse rate, and cardiac output, and by a lower estimated venous capacitance. The concomitant response of stroke volume and APRC did not differ appreciably between groups. CONCLUSION: Formerly preeclamptic women with a subnormal plasma volume differ from controls with a normal plasma volume by a reduced venous capacitance. These results support our hypothesis that, in these women, a subnormal plasma volume indicates the presence of a subnormal venous capacitance

Angiotensin II sensitivity in nonpregnant formerly preeclamptic women and healthy parous controls.

Contains fulltext : 58141.pdf (publisher's version ) (Closed access)BACKGROUND: In women prone to develop hypertensive complications, vascular reactivity fails to decrease in early pregnancy. Since hypertensive syndromes of pregnancy seem to be superimposed on a preexisting disorder, we tested the hypothesis that in formerly preeclamptic women, as compared to healthy parous controls, circulatory reactivity to angiotensin II is enhanced in the follicular phase of the menstrual cycle. METHODS: Sixty formerly preeclamptic women were subdivided into a hypertensive (HYPERT, n = 14), a normotensive thrombophilic (THROMB, n = 26), and a normotensive nonthrombophilic (ASYMPT, n = 20) subgroup. In these women and in 11 healthy parous controls we assessed at least 5 months postpartum at day 5 (+/-2) of the menstrual cycle the following variables: body weight, height, plasma volume, reactivity to infused angiotensin II of arterial blood pressure, heart rate, glomerular filtration rate (GFR), effective renal blood flow, and the hormones of the renin-angiotensin-aldosterone (RAAS) axis. RESULTS: At baseline, THROMB did not differ from controls. In contrast, ASYMPT exhibited slight overweight, reduced plasma volume, and reduced renal blood flow. HYPERT much resembled ASYMPT except for the overweight, renal perfusion, and GFR. Infusion of angiotensin II led to comparable decreases in renal perfusion and filtration, and to increases in blood pressure. However, sensitivity to this substance correlated inversely with relative and absolute sizes of the plasma volume compartment. CONCLUSION: Circulatory sensitivity to infused angiotensin II is comparable between nonpregnant formerly preeclamptic women and healthy parous controls. However, responsiveness to this agent is enhanced among women with a contracted plasma volume compartment, a condition commonly observed among formerly preeclamptic women

Non-heartbeating donation of kidneys for transplantation.

There is a persistent shortage of kidneys available for transplantation. In the early 1980s, therefore, we published the concept of non-heartbeating (NHB) donation; that is, procurement of kidneys from donors whose death has been accompanied by irreversible circulatory arrest. NHB donors are generally categorized using four definitions; category III (awaiting cardiac arrest) and category IV (cardiac arrest while braindead)--or 'controlled'--donors are the most suitable for initiating NHB donation programs. Delayed graft function is associated with use of kidneys from such donors, but has no effect on graft survival in the short or long term. Use of kidneys from category I (dead upon arrival at hospital) and category II (unsuccessfully resuscitated), or 'uncontrolled', donors is likewise associated with delayed graft function, but also with an increased risk of primary nonfunction. Viability testing of donated organs from these sources is a prerequisite for transplantation. Machine preservation parameters and enzyme release measurements help to distinguish viable from nonviable kidneys. The proportion of NHB donor kidneys in the total pool of postmortem kidneys differs considerably between countries. In The Netherlands, the proportion is nearly 50%. This figure is markedly higher than that in the US and Canada, where national programs have now been initiated to increase rates of NHB donation. In the future, warm preservation techniques might facilitate better viability testing, thereby increasing NHB donation from category I and II donors and further reducing the shortage of kidneys available for transplantation