Prediction of colloid osmotic pressure in renal patients.

BACKGROUND: Colloid osmotic pressure (COP) plays a major role in transcapillary fluid shift, including in the glomerular capillary. However, COP is generally estimated by quadratic equations derived from total plasma protein and/or albumin concentrations. The aim of this study was to assess the accuracy of such equations, and to determine the potential role of liver-derived non-albumin proteins in the maintenance of COP, especially in patients presenting a nephrotic syndrome. METHODS: COP was directly assessed with an osmometer in 170 patients (347 samples), and the results compared with calculated COP, using 4 previously published formulas [Brenner 1972, Canaan-Kühl 1993, Landis-Pappenheimer 1963, Navar 1977]. RESULTS: The 4 calculated COP values were strongly correlated with measured COP (range r = 0.88 - 0.96). However, in absolute terms, measured COP differed significantly from each of the 4 calculated mean values of COP (p < 0.001). Fibrinogen exerted per se a weak oncotic effect as measured in vitro. However, fibrinogen was highly related to albumin and presumably reflected the oncotic effect of other liver-derived non-albumin proteins. Inclusion of albumin and fibrinogen in a linear model provided an excellent fit for predicted COP with a highly significant correlation (r = 0.96, p < 0.001) over a wide range of COP values. The predicted equation was: COP(mmHg) = 6.89 x (albumin + fibrinogen) (g/dl) - 5.68. CONCLUSION: None of the 4 most commonly used formulas correctly predicted COP, and direct measurement of COP is still preferable for research studies. The introduction of fibrinogen into the formula estimating COP leads to higher accuracy, and therefore represents a more convenient model for routine evaluation.

[Use of Gadolinium as a contrast agent in the course of renal arterial angioplasty]. / Utilisation du Gadolinium comme produit de contraste au cours d'une angioplastie des artères rénales.

For a 72-year-old patient with chronic renal failure, and a renal artery stenosis, we used gadolinium as a contrast agent to perform a digital subtraction arteriography and subsequent arterial angioplasty. Ten ml of gadolinium were used for the arteriography, and during a second procedure 40 ml for the angioplasty, giving high quality images. Renal function remained stable after the procedure, while blood pressure was easier to control.

[The "absolute" cardiovascular risk]. / Le risque cardio-vasculaire "absolu".

Diagnosis of hypertension and the thresholds for therapeutic intervention are usually defined by arbitrary values, changed along time by the Societies of Hypertension. Absolute cardio-vascular risk takes into account the full spectrum of independent cardio-vascular risk factors that have been identified by large observational epidemiological studies including Framingham Study. The advantages and the limits of the "absolute" cardiovascular risk concept and its applicability to medical practice are extensively discussed in this paper.

[Absolute cardiovascular risk among nephrology patients]. / Risque cardio-vasculaire absolu chez les malades en néphrologie.

Patients with renal diseases (defined by proteinuria or pre-dialysis chronic renal failure) usually exhibit high cardiovascular morbidity and mortality. The true excess of risk associated with proteinuria or high creatinine level in this population is however poorly acknowledged. This paper aims to review the epidemiological evidence pointing at high cardio-vascular burden in these patients. This paper further analyzes whether the high cardio-vascular risk is related to a high prevalence of established risk factors or results from other factors more specific of renal diseases. Applicability to renal populations of "absolute" cardiovascular risk equations derived from Framingham Study is discussed.

[Antihypertensive treatment in type II diabetes and diabetic nephropathy]. / Traitement antihypertenseur du diabète et de la néphropathie diabétique de type II.

Hypertension is very prevalent in patients with type II diabetes. Beside increasing the cardiovascular risk, hypertension has several deleterious effects on the kidney: hypertension promotes the development of diabetic nephropathy, the progression from microalbuminuria to overt diabetic nephropathy and progression to end stage renal disease. In this review, we analyze systematically the benefit of antihypertensive therapy in patients with type II diabetes, with either normo-albuminuria, microalbuminuria or overt nephropathy. General considerations are developed about the general use of antihypertensive drugs in this population. An approach based on the prevention of the global or absolute cardiovascular risk is further recommended due to the very high cardiovascular burden in this diabetic patients.

[Antihypertensive treatment in type 1 diabetes and diabetic nephropathy]. / Traitement antihypertenseur du diabète et de la néphropathie diabétique de type 1.

In diabetic patient, hypertension is a major factor contributing to both cardiovascular morbidity-mortality and progression toward renal impairment. This review analyzes studies from the literature regarding the benefits of antihypertensive treatment at every stage of type 1 diabetes and diabetic nephropathy.

Abysmal prognosis of patients with type 2 diabetes entering dialysis.

INTRODUCTION: The importance of non-insulin-dependent diabetes mellitus (type II diabetes) as a leading cause of end-stage renal disease is now widely recognized. The purpose of this study was to assess life-prognosis and its predictors in a cohort of patients newly entering dialysis. MATERIAL AND METHODS: Eighty-four consecutive type II diabetes patients (40% of all patients) starting dialysis between 01/01/95 and 31/12/96 were studied retrospectively, focusing on clinical data at inception and life-prognosis after a mean follow-up of 211 days. Patients were divided into three groups, according to onset of renal failure: acute 11% (9/84), chronic 61% (51/84) and acutely aggravated chronic renal failure 28% (25/84). RESULTS: Patients (mean age 67 years) had long-standing diabetes (mean duration approximately 15 years), heavy proteinuria (approximately 3 g/24h) and diabetic retinopathy (67%). The average creatinine clearance (Cockcroft's formula) was 13 ml/min. Cardiovascular diseases were highly prevalent at the start of dialysis: history of myocardial infarction (26%), angina (36%) and acute left ventricular dysfunction (67%). More than 80% of the patients underwent the first session dialysis under emergency conditions, a situation in part related to late referral to the nephrology division (63% for chronic patients). A great majority of the patients were overhydrated when starting dialysis, as evidenced by the average weight loss of 6 kg, during the first month of dialysis, required to reach dry weight. Nearly 64% of the patients presented high blood pressure (> 140/90 mmHg) when starting dialysis despite antihypertensive therapy (mean: 2.3 drugs). The outcome of this type II diabetes population was dramatic: 32% (27/84) died after a mean follow-up of 211 days, mostly from cardiovascular diseases. The rate of recovery of renal function was low in both the acute and the acutely aggravated renal failure group (30% and 24%, respectively). Of note, iatrogenic nephrotoxic agents accounted for renal function impairment in nearly 30% of patients. CONCLUSION: Our observational study illustrates the high burden of cardiovascular diseases contrasting with sub-optimal cardiovascular therapeutic interventions in type II diabetes patients entering dialysis. Factors aggravating renal failure were mainly iatrogenic, and therefore largely avoidable. Late referral generally implied a poor clinical condition at the start of dialysis.