Hyperkalemia and the Decision to Admit
ABSTRACT & COMMENTARY
Source: Charytan D, Goldfarb DS. Indications for hospitalization of patients with hyperkalemia. Arch Intern Med 2000;160:1605-1611.
The authors endeavored to examine retrospectively the characteristics of patients admitted for hyperkalemia, and to compare those characteristics to a "similar" group of patients who received outpatient therapy for elevated potassium. The purpose of this comparison was to discover any differences between these groups, with an eye toward developing reasonable criteria for admission of patients with hyperkalemia. The study population was drawn from patients with an ICD-9 code for hyperkalemia, extracting only those patients (10) for whom the discharge summary revealed that they truly were admitted for the elevated potassium level itself. The outpatient group was derived from review of laboratory "panic" values (K+ ³ 6.1 mmol/L). After excluding those patients who were admitted for high potassium (1 of which was added to the first study group), those with hemolyzed specimens, those drawn on inpatients, and those values from the hemodialysis unit, 12 patients remained in the comparison group.
Demographic, medical, pharmacologic, laboratory, electrocardiographic, and treatment data were then abstracted from the records and compared. No significant differences were found between the groups with regard to potassium, blood urea nitrogen (BUN), creatinine, or bicarbonate levels, or change in potassium, BUN, or creatinine values from identifiable baselines. Electrocardiographic criteria were incomplete, owing largely to a lack of ECGs in the outpatient group. Numerous patients in both groups were on medications known to contribute to hyperkalemia (e.g., angiotensin converting-enzyme inhibitors, nonsteroidal anti-inflammatory agents, and trimethoprim). Symptomatology and treatment characteristics were variable. The authors concluded that since patients admitted to the hospital were clinically indistinguishable from those treated as outpatients and the justification for disposition decision often was not evident, perhaps these patients did not all need to be admitted. They proposed the following criteria for admission: severe hyperkalemia (K+ ³ 8.0 mmol/L with electrocardiographic changes other than peaked T waves); acute worsening of renal function; and supervening medical conditions.
COMMENT BY RICHARD A. HARRIGAN, MD, FAAEM
The title of this paper is eye-catching, in that we as emergency physicians must make the decision regarding admission of patients with elevated potassium levels, and (as the authors acknowledge) there are no existing criteria to use as guidelines. This paper is terminally flawed however, and I review it here lest an internist wave it at you in the future in an effort to block the admission of a patient with hyperkalemia.
The absence of statistical difference between two dissimilar groups (11 apples and 12 oranges, so to speak), in a study lacking power (23 total patients!), does not a decision rule make. People are often admitted not for one reason, or for rank-ordered reasons, but for multiple reasons, some of which are less tangible (assurance of close follow-up, availability of past laboratory data at the time of admission decision for trend analysis—to name just two examples relevant to this entity). There is obvious selection bias in this study: There was some reason or reasons why those caring for the individuals in the outpatient group did not decide to admit them, and similarly why those who were admitted were admitted. Certainly, the choice may have been arbitrary, but to assume it was—based on laboratory similarities between groups—is not reasonable. The authors allude to the fact that removal or correction of reversible conditions (e.g., medication adjustments) may render patients safe for discharge after ED reduction of hyperkalemia, and this point is well-taken. Furthermore, they found that offending medications were frequently not removed, which is noteworthy. Yet to propose these arbitrary criteria for hospitalization based upon a snippet of a patient population, without true data-based support, is ludicrous.
You have reached your article limit for the month. Subscribe now to access this article plus other member-only content.
- Award-winning Medical Content
- Latest Advances & Development in Medicine
- Unbiased Content