Difference In Serum Potassium Research Articles

Hypokalemia after theophylline intoxication. The effects of acute vs chronic poisoning

To characterize the frequency and pattern of hypokalemia (serum potassium level less than 3.5 mmol/L) after theophylline poisoning, we prospectively evaluated 88 consecutive patients with theophylline intoxication (serum theophylline concentration greater than or equal to 0.165 mmol/L). This mean admission serum theophylline concentration of this cohort was 0.331 mmol/L, with a range of 0.165 to 0.982 mmol/L. The simultaneous mean serum potassium concentration was 3.36 mmol/L (range, 2.20 to 5.80 mmol/L). Fifty-three patients (60%) were hypokalemic on hospital arrival. When, on the basis of recent ingestion, patients were separated into acute, chronic, or acute-on-chronic categories of theophylline intoxication, significant differences in serum potassium were found: Patients with acute theophylline intoxication had a mean serum potassium concentration of 2.94 mmol/L; 85% were hypokalemic. In contrast, patients with chronic theophylline intoxication had a mean serum potassium concentration of 3.83 mmol/L, with a 32% frequently of hypokalemia. These data demonstrate that hypokalemia is common after theophylline intoxication and has a significantly higher incidence after acute overdose. The difference in the frequency of hypokalemia between patients with acute vs chronic intoxication has unclear origins but may be related to the disparities in clinical course (particularly the appearance of seizures and cardiac arrhythmias) that have been observed after acute vs chronic theophylline intoxication.

Hypokalemia After Theophylline Intoxication

• To characterize the frequency and pattern of hypokalemia (serum potassium level &lt;3.5 mmol/L) after theophylline poisoning, we prospectively evaluated 88 consecutive patients with theophylline intoxication (serum theophylline concentration ≥0.165 mmol/L). The mean admission serum theophylline concentration of this cohort was 0.331 mmol/L, with a range of 0.165 to 0.982 mmol/L. The simultaneous mean serum potassium concentration was 3.36 mmol/L (range, 2.20 to 5.80 mmol/L). Fifty-three patients (60%) were hypokalemic on hospital arrival. When, on the basis of recent ingestion, patients were separated into acute, chronic, or acute-on-chronic categories of theophylline intoxication, significant differences in serum potassium were found: Patients with acute theophylline intoxication had a mean serum potassium concentration of 2.94 mmol/L; 85% were hypokalemic. In contrast, patients with chronic theophylline intoxication had a mean serum potassium concentration of 3.83 mmol/L, with a 32% frequency of hypokalemia. These data demonstrate that hypokalemia is common after theophylline intoxication and has a significantly higher incidence after acute overdose. The difference in the frequency of hypokalemia between patients with acute vs chronic intoxication has unclear origins but may be related to the disparities in clinical course (particularly the appearance of seizures and cardiac arrhythmias) that have been observed after acute vs chronic theophylline intoxication. (<i>Arch intern Med</i>. 1989;149:2725-2729)

Mild hypokalaemia is not a risk factor in treated hypertensives.

The possibility that hypokalaemia might increase the mortality of treated hypertensives in the Glasgow Blood Pressure Clinic has been examined by comparison of serum potassium in decedents and survivors and by calculation of age-adjusted mortality rates for patients grouped in quartiles of serum potassium measured at the last clinic visit. In this study, 3783 patients with non-malignant hypertension were followed for an average of 6.5 years and of these 1907 had one or more measurements of serum potassium during their last year of attendance. Serum potassium fell in 414 patients given diuretics with or without other drugs except beta-blockers. This fall was similar in those who died of ischaemic heart disease (3.71 mmol/l) and in those who survived (3.72 mmol/l). Serum potassium rose in 167 patients who received beta-blockers with or without other drugs except diuretics and fell slightly among 1326 patients taking other combinations of drugs. There were no significant differences in serum potassium between decedents and survivors in either of these treatment groups. Age-adjusted mortality in deaths per 1000 patient-years in the lowest quartile of serum potassium (less than 3.7 mmol/l) was 28.1 for men and 15.0 for women. Higher serum potassium was associated with slightly, but not significantly, higher mortality in both sexes. There was no relation between serum potassium and mortality in patients with left ventricular hypertrophy, nor was there a relation when death due to ischaemic heart disease was considered separately. Failure of hypokalaemia to predict outcome was confirmed by univariate and multivariate analyses which included, in addition to potassium, assessment of cigarette smoking, initial blood urea and electrocardiographic findings.(ABSTRACT TRUNCATED AT 250 WORDS)

Fixed‐Dose Combination Diuretics in Congestive Heart Failure: An Evaluation

Thirty-two patients with congestive heart failure were studied for their clinical and biochemical responses to the administration of two combination diuretic products (hydrochlorothiazide/spironolactone and hydrochlorothiazide/triamterene) and the single entity diuretic furosemide. Data from these studies revealed the following: 1. Comparison of the patients on furosemide with those receiving the combination products showed no difference in serum potassium or 24-hour potassium excretion. 2. Significant changes in blood urea nitrogen, plasma renin activity, and urinary aldosterone excretion were noted with both fixed-combination medications but not with furosemide. 3. The combination diuretics offered no clinical benefits over the single agent furosemide. 4. Therapy is best served by the use of a single effective diuretic agent for the treatment of most patients with congestive heart failure.