Safe and effective use of chronic transdermal estradiol for life-threatening uremic bleeding in a patient with coronary artery disease.

Uremic platelet dysfunction rarely causes significant bleeding in adequately dialyzed patients. When encountered, the management is complicated by a lack of well-supported treatment modalities. Estrogen use in uremic platelet dysfunction has been described, but enthusiasm for the treatment has been dampened by the risk of thrombotic events in vasculopathic dialysis patients. We present a patient on long-term peritoneal dialysis with coronary disease who developed recurrent life-threatening bleeding episodes secondary to uremia, where treatment with transdermal estrogen was used safely and effectively for a 24-month period.

Treating profound hyponatremia: a strategy for controlled correction.

An alcoholic patient presented with profound hyponatremia (serum sodium concentration, 96 mEq/L) caused by the combined effects of a thiazide diuretic, serotonin reuptake inhibitor, beer potomania, and hypovolemia. A computed tomographic scan of the brain was indistinguishable from one obtained 3 weeks earlier when he was normonatremic. Concurrent administration of 3% saline solution and desmopressin controlled the rate of correction to an average of 6 mEq/L daily and resulted in full neurologic recovery without evidence of osmotic demyelination. This case illustrates the value of controlled correction of profound hyponatremia.

Treatment of hyponatremia.

PURPOSE OF REVIEW: We review literature from the past 18 months on the treatment of hyponatremia. Therapy must address both the consequences of the untreated electrolyte disturbance (including fatal cerebral edema due to acute water intoxication) and the complications of excessive therapy (the osmotic demyelination syndrome). RECENT FINDINGS: Correction of hyponatremia by 4-6 mEq/l within 6 h, with bolus infusions of 3% saline if necessary, is sufficient to manage the most severe manifestations of hyponatremia. Planning therapy to achieve a 6 mEq/l daily increase in the serum sodium concentration can avoid iatrogenic brain damage by staying well clear of correction rates that are harmful. Conservative correction goals are wise because inadvertent overcorrection is common. Administration of desmopressin to halt a water diuresis can help prevent overcorrection; if overcorrection occurs, therapeutic relowering of the serum sodium concentration is supported by data in experimental animals and was found to be safe in a small observational clinical trial. Even mild and apparently asymptomatic hyponatremia may lead to falls because of impaired gait, and an increased likelihood of fracture because of hyponatremia-induced osteoporosis, a newly described entity. Recently approved vasopressin antagonists now make it possible to normalize the serum sodium concentration on a chronic basis, but practical considerations have limited their use.

The treatment of hyponatremia.

Virtually all investigators now agree that self-induced water intoxication, symptomatic hospital-acquired hyponatremia, and hyponatremia associated with intracranial pathology are true emergencies that demand prompt and definitive intervention with hypertonic saline. A 4- to 6-mmol/L increase in serum sodium concentration is adequate in the most seriously ill patients and this is best achieved with bolus infusions of 3% saline. Virtually all investigators now agree that overcorrection of hyponatremia (which we define as 10 mmol/L in 24 hours, 18 mmol/L in 48 hours, and 20 mmol/L in 72 hours) risks iatrogenic brain damage. Appropriate therapy should keep the patient safe from serious complications of hyponatremia while staying well clear of correction rates that risk iatrogenic injury. Accordingly, we suggest therapeutic goals of 6 to 8 mmol/L in 24 hours, 12 to 14 mmol/L in 48 hours, and 14 to 16 mmol/L in 72 hours. Inadvertent overcorrection owing to a water diuresis may complicate any form of therapy, including the newly available vasopressin antagonists. Frequent monitoring of the serum sodium concentration and urine output are mandatory. Administration of desmopressin to terminate an unwanted water diuresis is an effective strategy to avoid or reverse overcorrection.

Effect of off-pump coronary artery bypass graft surgery on postoperative acute kidney injury and mortality.

OBJECTIVE: Risk of mortality after cardiac surgery is associated with severity of acute kidney injury. The aim of this study is to examine the effect of off-pump coronary artery bypass surgery on the risk of postoperative acute kidney injury and its association with mortality. DESIGN: Observational cohort study. SETTING: Tertiary care center. PATIENTS: Some 10,061 patients underwent coronary artery bypass surgery (1998-2002), of which 1,365 patients underwent off-pump surgery. INTERVENTIONS: Acute kidney injury was defined as either requirement of dialysis or >/=50% decline in postoperative glomerular filtration rate but not requiring dialysis. We compared on- and off-pump surgeries and used propensity score matching to examine the effect of off-pump surgery on acute kidney injury and mortality. MEASUREMENTS AND MAIN RESULTS: We found that 2.6% on-pump and 1.2% off-pump patients developed acute kidney injury requiring dialysis among the 2,370 matched subjects (relative risk, 2.06; 95% confidence interval [CI], 1.36-3.36); 5.0% of on-pump patients suffered a >/=50% decline in glomerular filtration rate compared with 2.5% in off-pump group (relative risk, 2.00; 95% CI, 1.48-2.82). The mortality rate in the matched cohort was 2.3% for on-pump group vs. 0.6% in off-pump group (relative risk, 3.88; 95% CI, 2.29-9.50). Among matched patients with acute kidney injury, the risk of mortality was 13.14 (95% CI, 8.43-30.50) in patients requiring dialysis and 9.33 (95% CI, 4.83-19.00) in those with >/=50% decline in glomerular filtration rate but not requiring dialysis. CONCLUSIONS: Off-pump surgery is associated with a lower risk of developing acute kidney injury (regardless of its definition). The risk of mortality is incremental with worsening degrees of acute kidney injury. Lower risk of acute kidney injury may be one of the factors that offer a survival advantage after off-pump surgery.