Recurrent high anion gap metabolic acidosis secondary to 5-oxoproline (pyroglutamic acid).

High anion gap metabolic acidosis in adults is a severe metabolic disorder for which the primary organic acid usually is apparent by clinical history and standard laboratory testing. We report a case of recurrent high anion gap metabolic acidosis in a 48-year-old man who initially presented with anorexia and malaise. Physical examination was unrevealing. Arterial pH was 6.98, P co 2 was 5 mm Hg, and chemistry tests showed a bicarbonate level of 3 mEq/L (3 mmol/L), anion gap of 32 mEq/L (32 mmol/L), and a negative toxicology screen result, except for an acetaminophen (paracetamol) level of 7.5 mug/mL. Metabolic acidosis resolved with administration of intravenous fluids. Subsequently, he experienced 5 more episodes of high anion gap metabolic acidosis during an 8-month span. Methanol, ethylene glycol, acetone, ethanol, d -lactate, and hippuric acid screens were negative. Lactate levels were modestly elevated, and acetaminophen levels were elevated for 5 of 6 admissions. These episodes defied explanation until 3 urinary organic acid screens, obtained on separate admissions, showed striking elevations of 5-oxoproline levels. Inborn errors of metabolism in the gamma-glutamyl cycle causing recurrent 5-oxoprolinuria and high anion gap metabolic acidosis are rare, but well described in children. Recently, there have been several reports of apparent acquired 5-oxoprolinuria and high anion gap metabolic acidosis in adults in association with acetaminophen use. Acetaminophen may, in susceptible individuals, disrupt regulation of the gamma-glutamyl cycle and result in excessive 5-oxoproline production. Suspicion for 5-oxoproline-associated high anion gap metabolic acidosis should be entertained when the cause of high anion gap metabolic acidosis remains poorly defined, the anion gap cannot be explained reasonably by measured organic acids, and there is concomitant acetaminophen use.

Patients' descriptions of specific factors leading to modality selection of chronic peritoneal dialysis or hemodialysis.

OBJECTIVES: There has been increasing interest in understanding how patients with chronic renal failure choose between chronic peritoneal dialysis (CPD) and hemodialysis (HD) for renal replacement therapy. The purpose of the present study was to examine the influences and specific factors that patients identify as significant in choosing a specific dialysis modality for treatment of their end-stage renal disease (ESRD). PATIENTS AND DESIGN: 40 patients (20 CPD, 20 HD) who had started dialysis within the preceding 6 months were randomly selected to participate in the study. A structured interview was conducted with the patients, discussing and exploring what factors patients thought were important in helping them decide their treatment modality. The format of the interview was open-ended. Based on patients' comments, a taxonomy of the specific factors that influenced the patients' decisions was developed. SETTING: The study was conducted in a freestanding CPD unit and two freestanding HD units. RESULTS: All 20 CPD patients reported choosing their treatment modality; only 8 of the 20 HD patients reported having a choice of treatment modality. 18 of the 22 patients who participated in predialysis educational programs opted for CPD. 83% of the patients reported that their physician was important in influencing their treatment choice; however, the CPD patients relied more on written material and the opinions of their spouse/significant other or other family members in making their decisions. Issues of autonomy and control were important for 95% of patients choosing CPD. Both CPD and HD patients cited a variety of treatment-specific factors. The three most frequently cited reasons for choosing CPD were (1) flexibility of schedule (19 patients), (2) convenience of performing CPD in their own home (19 patients), and (3) the option of doing dialysis at night while sleeping (8 patients). The 8 HD patients who selected their treatment modality cited the desirability of having a planned schedule (7 patients) and letting nurses or other take care of them (5 patients). CONCLUSIONS: The present study explored factors perceived by patients as being important in determining their choice of renal replacement therapy. A taxonomy of patient influences and concerns has been developed to provide caregivers with a framework to structure their educational strategies and assist patients with progressive renal failure in making an informed choice of therapeutic modality for their ESRD treatment.