Albuterol and insulin for treatment of hyperkalemia in hemodialysis patients

We evaluated in maintenance hemodialysis patients the potassium lowering effects of intravenous insulin with glucose, nebulized albuterol, and a regimen combining both modalities. There was a similar decrease in plasma potassium following either insulin with glucose (0.65 +/- 0.09 mmol/liter) or albuterol (0.66 +/- 0.12 mmol/liter), and a substantially greater fall with the combined regimen (1.21 +/- 0.19 mmol/liter, P less than 0.02 vs. either drug alone). Baseline plasma glucose concentrations were similar (about 4.8 mmol/liter) prior to all three treatments. Following insulin with glucose, plasma glucose increased transiently. but then fell to 2.8 +/- 0.3 mmol/liter at one hour, with concentrations below 3 mmol/liter in 9 of 12 patients. None of the patients had symptoms of hypoglycemia. Plasma glucose increased to 6.8 +/- 0.5 mmol/liter with albuterol. After the combined drug regimen plasma glucose rose transiently and was back to baseline (4.7 +/- 0.7 mmol/liter) at one hour. Treatment with insulin or albuterol produced trivial increases in heart rate, whereas the combined drug regimen was associated with a significant rise (15.1 +/- 6.0 min-1). These observations suggest that albuterol and insulin with glucose are equally efficacious in lowering plasma potassium in uremic patients, and that the hypokalemic effects of the two drugs is additive. The hypoglycemic effect of insulin is attenuated by coadministration albuterol. Combined therapy with insulin, glucose and albuterol is efficacious and safe for the acute treatment of hyperkalemia in hemodialysis patients.

Acute effects of captopril and ibuprofen on proteinuria in patients with nephrosis

Captopril decreases protein excretion in patients with nephrosis. To evaluate whether captopril has an acute antiproteinuric effect and to evaluate the role of changes in renal hemodynamics or glomerular permselectivity on this effect, renal clearance studies were performed in patients without diabetes but with nephrosis. Protein excretion and renal hemodynamics were measured at baseline and after the administration of captopril. To measure the contribution of renal prostaglandins, patients were restudied on a separate day, after the combined administration of captopril and the prostaglandin synthetase inhibitor ibuprofen. Both treatments significantly reduced mean protein excretion, but the change was greater with combined therapy than with captopril alone (40.6% vs 20.0%). Mean glomerular filtration rate (GFR) decreased by 4.8% (not significant) and 16.5% (p less than 0.001), and filtration fraction (FF) decreased by 13.6% (p less than 0.001) and 14.9% (p less than 0.001) after captopril alone and combined therapy, respectively. No significant correlation was found between changes in proteinuria and changes in GFR or FF after treatment with captopril alone. In contrast, the decrease in proteinuria correlated with the change in GFR after combined drug administration (r = 0.68, p = 0.06). The ratio of immunoglobulin G to albumin clearance, an index of glomerular permselectivity, was unaffected by captopril but decreased significantly (by 43%) after combined drug administration. The results suggest that the acute antiproteinuric effect of captopril is not due to changes in FF, GFR, or glomerular perselectivity. The addition of ibuprofen enhances the antiproteinuric effect of captopril by decreasing the GFR as well as by enhancing the permselectivity of the glomerular capillary membrane.

Role of cigarette use in hyponatremia in schizophrenic patients

Urine volume and osmolality were studied in two schizophrenic patients with hyponatremia and six normal subjects after they smoked or ingested cigarettes. The results suggest that cigarette use may contribute to the development of hyponatremia by impairing water excretion.

Interaction of captopril and ibuprofen on glomerular and tubular function in humans

Renal hemodynamics and tubular solute and water handling were evaluated in normal subjects during water diuresis, before and after the acute administration of captopril, ibuprofen, or the combination of both drugs. The glomerular filtration increased after captopril administration but did not change after ibuprofen alone or in combination with captopril. Renal plasma flow increased with captopril alone and captopril plus ibuprofen but did not change after ibuprofen alone. Urine volume and Na excretion increased with captopril and decreased after ibuprofen; coadministration of ibuprofen attenuated the tubular effects produced by captopril alone. FELi, fractional delivery of solute to the distal nephron, and FELi-FENa, fractional distal reabsorption of solute, both significantly increased after captopril and decreased after ibuprofen but did not change with the combined regimen. (FELi-FENa)/FELi, fractional reabsorption of distally delivered Na, significantly decreased after captopril and increased after ibuprofen but remained unchanged after captopril plus ibuprofen. Thus captopril and ibuprofen have opposing effects on tubular Na and water handling, which are attenuated by the addition of the other drug. This interaction may have clinical relevance in patients with heart failure or hypertension, in whom captopril is used to enhance Na and water diuresis.

Sodium and water excretion in nephrotic patients: effects of changes in renal haemodynamics

1. Eight nephrotic patients were studied in order to evaluate the effects of acute changes in renal plasma flow and glomerular filtration rate on renal solute and water handling, in the absence of plasma volume expansion. 2. The subjects were studied first after the administration of captopril, a manoeuvre that increased renal plasma flow without a significant change in glomerular filtration rate, and a second time after receiving combined therapy with captopril and ibuprofen, a manoeuvre that decreased glomerular filtration rate without a significant change in renal plasma flow. 3. After captopril therapy, despite the increase in renal plasma flow, there was no significant change in proximal sodium reabsorption (as estimated from fractional lithium reabsorption), urine volume or urine osmolality. 4. The decrease in glomerular filtration rate observed after the administration of captopril plus ibuprofen was associated with decreases in fractional excretion of sodium and urine volume, and an increase in urine osmolality. The changes in these parameters of tubular function were proportionate to the changes in glomerular filtration rate. Fractional proximal sodium reabsorption increased substantially. 5. These observations suggest that, in the absence of plasma volume expansion, an increase in renal plasma flow does not increase sodium or water excretion by the nephrotic kidney. Moreover, during acute decreases in glomerular filtration rate, glomerulotubular balance appears to be disrupted, resulting in disproportionately high rates of proximal tubule sodium reabsorption.

Renal sodium and water handling in hypothyroid patients: the role of renal insufficiency

The mechanism responsible for renal tubular abnormalities in sodium and water excretion in hypothyroid patients is poorly understood. To evaluate the possible contribution of the reduced glomerular filtration rate of hypothyroidism to these abnormalities, tubular function in hypothyroid patients was compared with that in patients with chronic renal failure and in normal subjects. The lithium clearance method and oral water loading were used to evaluate parameters of tubular sodium and water handling, respectively. The hypothyroid and the chronic renal failure patients were selected to have similar reductions in glomerular filtration rate. As compared to the normal subjects, the hypothyroid and chronic renal failure patients had a decrease in proximal sodium reabsorption and an increase in distal sodium reabsorption. The changes in tubular handling of sodium were not different in the hypothyroid and the chronic renal failure patients. Maximal urinary flow rate and free water clearances were similarly reduced in the hypothyroid patients and the chronic renal failure patients. For all subjects studied, proximal sodium reabsorption and maximal urinary volume were directly correlated with the glomerular filtration rate, and distal nephron sodium reabsorption was proportionate to delivery of sodium from the proximal tubule. The results suggest that the abnormalities in tubular sodium and water handling in hypothyroid patients are comparable to those present in other patients with a similar degree of renal insufficiency. Thus, the tubular abnormalities in hypothyroidism may be a consequence of the associated decrease in glomerular filtration rate.

Renal abnormalities in sickle cell disease

Many renal structural and functional abnormalities have been associated with sickle cell disease. The patients have an impaired urinary concentrating ability but an intact diluting capacity. There are defects in both urinary acidification and potassium excretion, although overt metabolic acidosis and hyperkalemia occur infrequently. Proximal tubular function is supranormal, as manifested by increased reabsorption of phosphate and increased secretion of creatinine. The former results in mild hyperphosphatemia, while the latter causes substantial overestimation of the glomerular filtration rate (GFR) by creatinine clearance. Both GFR and renal plasma flow are increased in young patients with sickle cell disease, but prostaglandin inhibitors decrease the GFR. The GFR progressively decreases with increasing age. Proteinuria, and even nephrotic syndrome, are relatively frequent; the most common renal lesion in children is focal glomerular sclerosis, which may be associated with progressive deterioration in renal function. Glomerular hyperfiltration has been implicated in the pathogenesis of the glomerular lesions, as well as in the development of renal failure. In patients with end-stage renal disease, both hemodialysis and kidney transplantation have been successful. Recurrent hematuria is a relatively common problem in patients with sickle cell disease. The bleeding usually remits spontaneously, but occasionally requires therapy with aminocaproic acid. Papillary necrosis may occur, and is thought to result from medullary ischemia.

Insulin in the acute renal adaptation to dietary phosphate restriction in the rat

Dietary phosphate restriction produces a rapid increase in tubular reabsorption of phosphate. To evaluate whether insulin is important in the acute renal adaptation following a low phosphate meal, four groups of conscious rats were studied by renal clearance methods, following a single meal by gavage. Group A received a normal (0.8%) phosphate meal, followed by saline infusion; Group B, a low (0.03%) phosphate meal, followed by saline infusion; Group C, a low phosphate meal, followed by infusion of somatostatin to suppress endogenous insulin secretion; and Group D, a low phosphate meal, followed by infusion of somatostatin plus insulin. Baseline plasma phosphate, insulin, glomerular filtration rate, and fractional excretion of phosphate were similar in all four groups. Following a low phosphate meal in Groups B, C, and D, there was a decrease in plasma phosphate, as compared with Group A. Whereas fractional excretion of phosphate decreased when plasma phosphate fell in Group B, administration of somatostatin (Group C) prevented the drop in fractional excretion of phosphate, despite a lower plasma phosphate. The addition of exogenous insulin (Group D) restored the antiphosphaturic effect of the low phosphate meal. These results suggest that insulin contributes to the acute decrease in phosphate excretion following a low phosphate meal.

Drug-induced meningitis

Meningitis is usually produced by an infectious agent, but there are multiple noninfectious causes. Medications may produce both acute and recurrent meningitis. We present a patient with 3 episodes of aseptic meningitis due to trimethoprim-sulfamethoxazole, and then review the topic of drug-induced meningitis.

Tubulointerstitial nephritis due to vancomycin

Vancomycin was used to treat a patient with Staphylococcus aureus endocarditis. After 3 weeks of therapy, the patient developed a diffuse maculopapular rash, which resolved upon stopping the drug. Rechallenge with vancomycin several days later resulted in reappearance of the rash and rapid onset of acute anuric renal failure. Renal biopsy revealed acute granulomatous interstitial nephritis. This is the first report of biopsy-proven vancomycin-induced acute interstitial nephritis. Renal function should be monitored closely in patients receiving vancomycin therapy.

Protein S and C antigen levels in proteinuric patients: dependence on type of glomerular pathology

The cause of the thrombotic tendency in nephrotic patients is unknown. Recent reports of thrombotic complications in patients with deficiencies of protein C or protein S (natural inhibitors of coagulation) have raised the possibility that decreased levels of these proteins may play a role in the hypercoagulable state of nephrotic patients. We measured the levels of protein C, total protein S, and free protein S antigens in 42 patients (21 nephrotic and 21 non-nephrotic) with one of four types of glomerular pathology: diabetic nephropathy (DM), focal glomerular sclerosis (FGS), membranous glomerulonephritis (MGN), and chronic renal failure due to hypertension (CRF). Protein C and total protein S antigen levels were significantly higher in FGS and MGN than they were in DM or CRF. Free protein S levels were lower in DM than they were in MGN. Protein C, total protein S, and free protein S levels did not significantly correlate with either serum albumin or degree of proteinuria. The mean levels of the three proteins did not differ between nephrotic and non-nephrotic patients. Free protein S and protein C were, however, significantly correlated (P less than .005 and P less than .002, respectively) with the type of glomerular pathology, independent of differences in age, sex, serum albumin, or degree of proteinuria. These data suggest that abnormalities of free protein S and protein C are related to the nature of the underlying renal disease, rather than to the degree of proteinuria.

Indomethacin in the treatment of lithium-induced nephrogenic diabetes insipidus

Nephrogenic diabetes insipidus (NDI) is a frequent complication in patients receiving long-term lithium therapy. Both thiazide diuretics and amiloride may reduce the polyuria, but the use of each is associated with problems. We report the results of a clinical trial using the nonsteroidal anti-inflammatory drug indomethacin to treat a patient with well-documented lithium-induced NDI that persisted following cessation of lithium treatment. The administration of a single dose of indomethacin resulted in a dramatic decrease in urine volume and increase in urine osmolality that persisted for several hours, and was independent of renal hemodynamic changes. Subsequently, the patient experienced a sustained, favorable effect on her polyuria during long-term (3 months) indomethacin therapy without a deleterious effect on her renal function. Indomethacin may be a useful therapeutic tool for the amelioration of lithium-induced NDI.

Nebulized albuterol for acute hyperkalemia in patients on hemodialysis

STUDY OBJECTIVE

To determine the efficacy and safety of nebulized albuterol in the acute treatment of hyperkalemia in patients on chronic hemodialysis.

DESIGN

Prospective, double-blind, and placebo-controlled study.

SETTING

Outpatient hemodialysis clinic at a university medical center.

PATIENTS

Ten patients on maintenance hemodialysis who had chronic hyperkalemia.

INTERVENTIONS

Patients received nebulized albuterol therapy (10 mg or 20 mg) or placebo (saline) on three separate occasions, serial measurements of plasma potassium levels, blood pressure, and pulse were then taken for a 2-hour period.

MEASUREMENTS AND MAIN RESULT

Patients had a significant decrease in plasma potassium concentrations that was evident by 30 minutes and sustained for at least 2 hours after albuterol treatment. After the administration of 10- and 20-mg doses of albuterol, the maximal decrease in the plasma potassium levels was 0.62 +/- 0.09 and 0.98 +/- 0.14 mmol/L (SE), respectively. Nebulized saline administration did not produce a significant change in the plasma potassium concentrations. Patients did not develop symptoms or significant changes in blood pressure or heart rate with albuterol treatment.

CONCLUSIONS

In the doses used, nebulized albuterol therapy resulted in a prompt and significant decrease in the plasma potassium concentrations in patients on hemodialysis, and caused no adverse cardiovascular effects. This treatment should be considered as an important adjunct for acute treatment of serious hyperkalemia in this population of patients.

Effects of nonsteroidal antiinflammatory drugs on renal function in sickle cell anemia

Renal hemodynamics and solute and water handling were evaluated in 19 sickle cell patients and 8 matched normal subjects during water diuresis, before and after acute oral administration of a nonsteroidal antiinflammatory drug (NSAID). Baseline GFR and RPF were higher in the patients compared to the normals. In contrast to normals, indomethacin and sulindac induced a 16% and 14% decrease in GFR, respectively. Indomethacin resulted in a slight increase in UOsm in normals, but a substantially greater rise in the patients. Following indomethacin a greater fall in FENa, fractional solute delivery to the diluting segment of the nephron [(CH2O + CNa + K)/GFR], fractional solute reabsorption in the diluting segment [CH2O/GFR] and the fraction of distally delivered solute reabsorbed [CH2O/(CH2O + CNa + K)] was observed in the sickle cell patients than in the normal subjects. A similar trend, but of significantly lesser magnitude than that induced by indomethacin, was observed following sulindac in the sickle cell patient. The data imply that the supranormal GFR observed in the sickle cell patients was prostaglandin-mediated. The effects of NSAID's on renal solute and water handling in the sickle cell patients are compatible with a prostaglandin-dependent decreased salt reabsorption in the medullary thick ascending limb of Henle, together with a hyperfunctioning proximal tubule. The data also imply an additional indomethacin-sensitive antinatriuretic effect in the diluting segment in these patients. Moreover, the results suggest that in sickle cell anemia sulindac may not have a "renal sparing" advantage over other NSAID's.

Minimal change glomerulonephropathy and interstitial infiltration with mycosis fungoides

The nephrotic syndrome developed in a patient with mycosis fungoides shortly after systemic involvement by his tumor occurred. Renal biopsy examination revealed atypical lymphocytic interstitial infiltration and changes consistent with minimal change glomerulonephropathy. The patient's proteinuria decreased following steroid therapy. This is the first report of an association between minimal change glomerulonephropathy and a proven T-cell malignant lymphoma. The implications are discussed with reference to the literature.

Complications with permanent peritoneal dialysis catheters: experience with 154 percutaneously placed catheters

A prospective study evaluated the complications in 154 patients in whom a permanent peritoneal dialysis catheter was inserted percutaneously from April 1982 to June 1986. Obstruction to flow and fluid leakage occurred in 9.2 and 2.6% of the catheters, respectively. Catheter survival was 64.6 and 48.6% at 1- and 2-year follow-up, respectively. The complication rates and survival of percutaneously placed catheters was comparable to those reported for surgically placed catheters. Percutaneous insertion of Tenckhoff catheters is a viable alternative to using the surgical technique.

Prolonged hypotension after initial minoxidil dose

Severe prolonged hypotension developed in a hypertensive patient several hours after the initial doses of minoxidil therapy. Hemodynamic measurements revealed a markedly low systemic vascular resistance and a markedly high cardiac output. Other causes of hypotension were ruled out. The patient's hemodynamic abnormalities lasted three days after minoxidil therapy was discontinued, and she then reverted to hypertension. Thus, a 10-mg starting dose of minoxidil may produce profound life-threatening hypotension, which can last up to 72 hours.