Use of urine specific gravity to improve screening for albuminuria.

The albumin to creatinine ratio (ACR) can be used to measure urine albumin excretion rates, but is inconvenient and expensive. More rapid and less expensive screening methods estimate only albumin concentration and are subject to errors caused by variation in urine volume. We examined whether urine specific gravity could be used in place of urine creatinine to correct albumin concentration for differences in urine volume in 50 patients. Urine specific gravity accurately estimated urine creatinine concentration (r = 0.79, P < 0.001). The albumin estimated-creatinine ratio (ACestR) in random spot urine sample correlated with urine albumin excretion measured in a 24-hour urine collection (r = 0.98, P < 0.001), as did the ACR (r = 0.95, P < 0.001). For determining microalbuminuria, the sensitivity (0.88) and specificity (0.93) of the ACestR were similar to those of ACR (0.89 and 0.93, respectively). Unfortunately, the sensitivity (0.63) of the Micral-Test was relatively poor, and was only slightly improved by correcting for urine specific gravity (0.69) in this small sample of patients. Nevertheless, these results suggest that as rapid methods for measuring urine albumin concentration improve, combining them with urine specific gravity might produce a less expensive and more convenient alternative to the ACR.

Risk factors for nephropathy and cardiovascular disease in diabetic Northern Minnesota American Indians.

Although complications of diabetes are common among Southwest American Indians, little is known about diabetes and associated risk factors for nephropathy and cardiovascular disease in other genetically distinct tribes. We conducted a retrospective analysis of 665 diabetic patients at two Chippewa Indian reservations in northern Minnesota to evaluate the prevalence of risk factors for diabetic nephropathy and cardiovascular disease. In 79 patients, a more detailed study was carried out, including an assessment of renal function and urinary albumin excretion (UAE). The overall prevalences of proteinuria and hypertension were 47.9% and 62.6%, respectively. Proteinuria was observed more often in hypertensive than in non-hypertensive patients (55.2% vs 44.4%, p < 0.05), and in patients with diabetes for longer than 10 years (57% vs 40% for diabetes less than 10 years, p < 0.05). Although hypercholesterolemia (total cholesterol > or = 200 mg/dl) was observed in 54% of patients, there was no relationship between hypercholesterolemia and proteinuria. In the 79 patients studied in more detail, UAE was greater in hypertensive patients compared to non-hypertensive patients (606 +/- 15600 mg/24h vs 101 +/- 157 mg/24 h, p < 0.05), and in patients with diabetes for 10 years or longer compared to patients in the first decade of disease (748 +/- 1732 mg/24 h vs 96 +/- 171 mg/24 h, p < 0.05). Hypercholesterolemia and elevated LDL-cholesterol (> 130 mg/dl) were observed in 56% and 49% of patients, respectively, but were not associated with increased UAE. In contrast, hypertriglyceridemia (> 250 mg/dl) was associated with an elevated UAE (932 +/- 2150 mg/24 h vs 245 +/- 735 mg/24h, p < 0.05). Increased lipoprotein(a) was found in patients with overt albuminuria. In summary, the prevalence of risk factors for diabetic nephropathy and associated cardiovascular disease is high in Chippewa American Indians in northern Minnesota. Although detecting abnormal UAE may be useful in identifying high-risk patients who may benefit from early intervention, traditional risk factors such as hypercholesterolemia may not explain the risk associated with increased UAE.

Evaluation of two intravenous single-bolus methods for measuring effective renal plasma flow.

This open-label, three-way crossover study examined the feasibility of measuring effective renal plasma flow (ERPF) using a single intravenous (IV) bolus method. Eight healthy young adults (four women aged 28 +/- 5 years [mean +/- SD] and four men aged 30 +/- 7 years) received on separate days an IV bolus of p-aminohippurate (PAH) 10 mg/kg, an IV bolus of phenolsulfonphthalein (PSP) 1 mg/kg, and the standard constant-rate IV infusion of PAH. The renal clearance (CLR) and plasma clearance (CLP) of PAH after constant infusion were 623.7 +/- 62.9 and 869.0 +/- 58.8 mL/min/1.73 m2, respectively. After PAH bolus injection, CLR and CLP were 538.9 +/- 110.8 and 677.6 +/- 122.4 mL/min/1.73 m2, respectively. After PSP bolus injection, CLR and CLP were 252.8 +/- 57.9 and 350.0 +/- 41.3 mL/min/1.73 m2, respectively. The ERPF measured by PSP bolus injection was significantly lower (P < 0.05) than by PAH infusion. The CLP of PAH after IV bolus injection was significantly lower than after IV infusion when men and women were analyzed together (P < 0.05). However, there appeared to be a greater magnitude of difference between the CLR after IV bolus and infusion of PAH for women than for men. In summary, PSP administered as an IV bolus injection does not appear to be a reliable marker of ERPF. The difference in ERPF determined by the PAH infusion and bolus methods may require further evaluation.

A randomized study of ciprofloxacin versus ceftriaxone in the treatment of nursing home-acquired lower respiratory tract infections.

OBJECTIVE: To compare the efficacy and safety of ciprofloxacin and ceftriaxone in patients with nursing home-acquired lower respiratory tract infections requiring initial hospitalization. DESIGN: Prospective, randomized trial. SETTING: Extended care nursing homes affiliated with a teaching hospital. PATIENTS: Fifty patients aged 60 years or older with normal or mildly impaired renal function admitted to the hospital for treatment of lower respiratory tract infections. INTERVENTIONS: Twenty-four patients received initial therapy with intravenous ciprofloxacin, 200 mg every 12 hours (19 patients) or 400 mg every 12 hours (5 patients) during the acute phase followed by 750 mg orally every 12 hours during the convalescence phase. Twenty-six patients received initial therapy with intravenous ceftriaxone, 2 g every 24 hours during the acute phase followed by 1 g administered intramuscularly every 24 hours during the convalescent phase. The total duration of therapy was 14 days. MAIN OUTCOME MEASUREMENTS: Successful outcome was defined as resolution or marked improvement in clinical signs and symptoms of lower respiratory tract infection upon completion of the treatment course. RESULTS: Twelve (50%) of the ciprofloxacin-treated and 14 (54%) of ceftriaxone-treated patients had successful outcomes. Recurrent oropharyngeal aspiration was the reason for treatment failure in most patients refractory to either antibiotic. Mortality during therapy was 8% in each group. From 21 satisfactory sputum specimens collected, S. pneumoniae was the most common isolate, followed by H. influenzae and other Gram-negative bacteria. Ciprofloxacin therapy was well tolerated; ceftriaxone therapy was discontinued in two patients (8%) due to adverse reactions (intramuscular pain and drug fever). CONCLUSIONS: Sequential intravenous/oral ciprofloxacin appears to be as safe and effective as sequential intravenous/intramuscular ceftriaxone. The optimal dosage of intravenous ciprofloxacin in this patient population appears to be 400 mg every 12 hours; however, additional clinical and pharmacokinetic studies with this regimen are warranted.

Adjunctive therapy with intravenous human immunoglobulin G improves survival of patients with acute renal failure.

The objective of this prospective, randomized, double-blind, placebo-controlled clinical trial was to evaluate the efficacy of adjunctive therapy with iv human immunoglobulin G in reducing the morbidity and mortality associated with acute renal failure. Forty patients greater than or equal to 18 yr of age who were identified within 48 h of the onset of acute renal failure and who met the enrollment criteria were enrolled in the study. Thirty-five patients were considered evaluable. Patients were grouped according to the admitting service (medical or surgical/trauma) and were randomized to receive either immunoglobulin G (400 mg/kg body wt) or placebo (normal saline; 8 mL/kg body wt) at study entry and then weekly thereafter for a maximum of 4 doses. The groups were well balanced with respect to demographics, clinical presentation, and severity of illness (APACHE II scores). A significant reduction in mortality at 42 days after study entry was observed. Two of 17 (12%) patients in the immunoglobulin G-treated group compared with 8 of 18 (44%) patients in the placebo-treated group died (P = 0.025). No differences were observed in the frequency of major complications that occurred in association with acute renal failure. However, in patients who manifested infection, greater survival was observed in the immunoglobulin G treatment group. The results suggest that immunoglobulin G administered at the onset of acute renal failure reduced mortality possibly by decreasing the severity of infectious complications associated with the occurrence of of acute renal failure.(ABSTRACT TRUNCATED AT 250 WORDS)