Serum Potassium Levels In Patients Research Articles

Effect of Patiromer on Serum Potassium Level in Patients With Hyperkalemia and Diabetic Kidney Disease

ImportanceHyperkalemia is a potentially life-threatening condition predominantly seen in patients treated with renin-angiotensin-aldosterone system (RAAS) inhibitors with stage 3 or greater chronic kidney disease (CKD) who may also have diabetes, heart failure, or both.ObjectivesTo select starting doses for a phase 3 study and to evaluate the long-term safety and efficacy of a potassium-binding polymer, patiromer, in outpatients with hyperkalemia.Design, Setting, and ParticipantsPhase 2, multicenter, open-label, dose-ranging, randomized clinical trial (AMETHYST-DN), conducted at 48 sites in Europe from June 2011 to June 2013 evaluating patiromer in 306 outpatients with type 2 diabetes (estimated glomerular filtration rate, 15 to <60 mL/min/1.73 m2 and serum potassium level >5.0 mEq/L). All patients received RAAS inhibitors prior to and during study treatment.InterventionsPatients were stratified by baseline serum potassium level into mild or moderate hyperkalemia groups and received 1 of 3 randomized starting doses of patiromer (4.2 g [n = 74], 8.4 g [n = 74], or 12.6 g [n = 74] twice daily [mild hyperkalemia] or 8.4 g [n = 26], 12.6 g [n = 28], or 16.8 g [n = 30] twice daily [moderate hyperkalemia]). Patiromer was titrated to achieve and maintain serum potassium level 5.0 mEq/L or lower.Main Outcomes and MeasuresThe primary efficacy end point was mean change in serum potassium level from baseline to week 4 or prior to initiation of dose titration. The primary safety end point was adverse events through 52 weeks. Secondary efficacy end points included mean change in serum potassium level through 52 weeks.ResultsA total of 306 patients were randomized. The least squares mean reduction from baseline in serum potassium level at week 4 or time of first dose titration in patients with mild hyperkalemia was 0.35 (95% CI, 0.22-0.48) mEq/L for the 4.2 g twice daily starting-dose group, 0.51 (95% CI, 0.38-0.64) mEq/L for the 8.4 g twice daily starting-dose group, and 0.55 (95% CI, 0.42-0.68) mEq/L for the 12.6 g twice daily starting-dose group. In those with moderate hyperkalemia, the reduction was 0.87 (95% CI, 0.60-1.14) mEq/L for the 8.4 g twice daily starting-dose group, 0.97 (95% CI, 0.70-1.23) mEq/L for the 12.6 g twice daily starting-dose group, and 0.92 (95% CI, 0.67-1.17) mEq/L for the 16.8 g twice daily starting-dose group (P < .001 for all changes vs baseline by hyperkalemia starting-dose groups within strata). From week 4 through week 52, statistically significant mean decreases in serum potassium levels were observed at each monthly point in patients with mild and moderate hyperkalemia. Over the 52 weeks, hypomagnesemia (7.2%) was the most common treatment-related adverse event, mild to moderate constipation (6.3%) was the most common gastrointestinal adverse event, and hypokalemia (<3.5 mEq/L) occurred in 5.6% of patients.Conclusions and RelevanceAmong patients with hyperkalemia and diabetic kidney disease, patiromer starting doses of 4.2 to 16.8 g twice daily resulted in statistically significant decreases in serum potassium level after 4 weeks of treatment, lasting through 52 weeks.Trial Registrationclinicaltrials.gov Identifier: NCT01371747

Effects of oral sodium phosphate solution, as a colonpreparation agent, on the serum potassium levelin patients undergoing colonoscopy at aSecondary Care Community Hospital

Effects of oral sodium phosphate solution, as a colonpreparation agent, on the serum potassium levelin patients undergoing colonoscopy at aSecondary Care Community Hospital

Sodium Zirconium Cyclosilicate in Hyperkalemia

BackgroundHyperkalemia (serum potassium level, >5.0 mmol per liter) is associated with increased mortality among patients with heart failure, chronic kidney disease, or diabetes. We investigated whether sodium zirconium cyclosilicate (ZS-9), a novel selective cation exchanger, could lower serum potassium levels in patients with hyperkalemia.MethodsIn this multicenter, two-stage, double-blind, phase 3 trial, we randomly assigned 753 patients with hyperkalemia to receive either ZS-9 (at a dose of 1.25 g, 2.5 g, 5 g, or 10 g) or placebo three times daily for 48 hours. Patients with normokalemia (serum potassium level, 3.5 to 4.9 mmol per liter) at 48 hours were randomly assigned to receive either ZS-9 or placebo once daily on days 3 to 14 (maintenance phase). The primary end point was the exponential rate of change in the mean serum potassium level at 48 hours.ResultsAt 48 hours, the mean serum potassium level had decreased from 5.3 mmol per liter at baseline to 4.9 mmol per liter in the group of patients who received 2.5 g of ZS-9, 4.8 mmol per liter in the 5-g group, and 4.6 mmol per liter in the 10-g group, for mean reductions of 0.5, 0.5, and 0.7 mmol per liter, respectively (P<0.001 for all comparisons) and to 5.1 mmol per liter in the 1.25-g group and the placebo group (mean reduction, 0.3 mmol per liter). In patients who received 5 g of ZS-9 and those who received 10 g of ZS-9, serum potassium levels were maintained at 4.7 mmol per liter and 4.5 mmol per liter, respectively, during the maintenance phase, as compared with a level of more than 5.0 mmol per liter in the placebo group (P<0.01 for all comparisons). Rates of adverse events were similar in the ZS-9 group and the placebo group (12.9% and 10.8%, respectively, in the initial phase; 25.1% and 24.5%, respectively, in the maintenance phase). Diarrhea was the most common complication in the two study groups.ConclusionsPatients with hyperkalemia who received ZS-9, as compared with those who received placebo, had a significant reduction in potassium levels at 48 hours, with normokalemia maintained during 12 days of maintenance therapy. (Funded by ZS Pharma; ClinicalTrials.gov number, NCT01737697.)

Rationale, Design, and Baseline Characteristics of ARTS-DN: A Randomized Study to Assess the Safety and Efficacy of Finerenone in Patients with Type 2 Diabetes Mellitus and a Clinical Diagnosis of Diabetic Nephropathy

Background/Aims: Finerenone decreases albuminuria in patients having heart failure with reduced ejection fraction and mild-to-moderate (stage 2-3) chronic kidney disease. The MinerAlocorticoid Receptor Antagonist Tolerability Study-Diabetic Nephropathy (ARTS-DN; NCT01874431) is a multicenter, randomized, double-blind, placebo-controlled, parallel-group, phase 2b study. ARTS-DN investigated whether the mineralocorticoid receptor antagonist finerenone reduces albuminuria without causing major alterations in serum potassium levels in patients with type 2 diabetes mellitus and a clinical diagnosis of DN who were receiving a renin-angiotensin-system (RAS) inhibitor. Methods: Patients were randomized to oral finerenone 1.25-20 mg or placebo once daily. The primary objectives were to assess the ratio of the urinary albumin-to-creatinine ratio at day 90 to that at baseline in patients receiving finerenone, and to compare it with that in the placebo group. Additional exploratory analyses included evaluating changes from baseline in serum potassium levels, efficacy and safety biomarkers, and health-related quality of life. Results: Of 1,501 patients screened, 821 (the sample population) received at least one dose of finerenone/placebo. Baseline characteristics included: male, 77.8%; white, 84.2%; very high albuminuria (formerly macroalbuminuria), 38.4%; high albuminuria (formerly microalbuminuria), 60.3%; median (range) estimated glomerular filtration rate, 66.3 (24.5-130.7) ml/min/1.73 m²; and systolic blood pressure (mean ± standard deviation), 138.1 ± 14.4 mm Hg. There was a history of cardiovascular disease in 39.6%, diabetic neuropathy in 20.0%, and diabetic retinopathy in 19.9% of patients. Conclusion: ARTS-DN is the first phase 2b trial of finerenone in combination with a RAS inhibitor in patients with type 2 diabetes mellitus and a clinical diagnosis of DN.

EFFECT OF RAMIPRIL ON GLYCOSYLATED HEMOGLOBIN AND LIVER FUNCTION TEST IN PATIENTS OF DIABETIC NEPHROPATHY

Background: Diabetic nephropathy (DN) is a chronic complication of diabetes mellitus with a growing incidence. Therefore, it is essential to have a better understanding of it, especially in relation to prevention and aggressive management to avoid progression to end-stage renal disease. Methods: This prospective randomized study represented the effects of ramipril on glycosylated hemoglobin (HbA1c), liver function tests (LFT), mean arterial blood pressure, and serum potassium level in patients diagnosed with DN, with concomitant mild to moderate hypertension. 135 diagnosed patients with DN treated with ramipril 5 mg daily for 3 months were involved in this study. Blood samples were taken from all patients and analyzed for HbA1c, LFT including alanine aminotransferase (ALT), aspartate aminotransferase (AST), serum alkaline phosphatase (ALP), and bilirubin with serum potassium level. After 3 months of treatment with ramipril (5 mg daily), blood samples were collected and analyzed again to determine the same parameters. Results: Ramipril produced a significant reduction in (HbA1c) of hypertensive patients (p<0.05), whereas, serum levels of ALT, AST, ALP, and bilirubin were significantly elevated. The results indicated that ramipril may cause liver injury. Meanwhile, the mean arterial pressure was decreased significantly by ramipril (p<0.05). Conclusion: The present study concluded that: ramipril significantly reduced the percentage of HbA1c but may cause liver injury, monitoring of liver enzymes is advisable for patients on ramipril.

Editorial Comment: Recurrent Episodes of Weak Spells in a 15 Year Old Boy

(1) This patient was referred to a neurologist by the cardiologist with the request that he evaluate and recommend therapy for the episodes of weakness only to be told that this was not periodic paralysis (PP), as the K level was not altered during the spells. The serum potassium level in patients with PP is not useful in the diagnosis. If it is high or low, it does not secure the diagnosis of hyperkalemic or hypokalemic PP and if it is normal it does not rule out the diagnosis of either type of PP. Perhaps if the serum K level could be monitored from just before an attack through the attack one would see a relative change (either up or down

Relation of Serum Potassium Level to Long-Term Outcomes in Patients With Acute Myocardial Infarction

Potassium plays a key role in normal myocardial function, and current guidelines recommend that serum potassium levels be maintained from 4.0 to 5.0 mEq/L in patients with acute myocardial infarction (AMI). However, the impact of serum potassium levels on long-term mortality has not been evaluated. We retrospectively studied 1,924 patients diagnosed with AMI. The average serum potassium levels measured throughout the hospitalization were obtained and statistically analyzed. Patients were categorized into 5 groups to determine the relation between mean serum potassium and long-term mortality: <3.5, 3.5 to <4.0, 4.0 to <4.5, 4.5 to <5.0, and ≥5 mEq/L. The long-term mortality was lowest in the group of patients with potassium levels of 3.5 to <4.0 mEq/L, whereas mortality was higher in the patients with potassium levels≥4.5 or <3.5 mEq/L. In a multivariate Cox-proportional regression analysis, the mortality risk was greater for serum potassium levels of >4.5 mEq/L (hazard ratio [HR] 1.71, 95% confidence interval [CI] 1.04 to 2.81 and HR 4.78, 95% CI 2.14 to 10.69, for patients with potassium levels of 4.5 to <5.0 mEq/L and ≥5.0, respectively) compared with patients with potassium levels of 3.5 to <4.0 mEq/L. The mortality risk was also higher for patients with potassium levels<3.5 mEq/L (HR 1.55, 95% CI 0.94 to 2.56). In contrast to the association with long-term mortality, there was no relation between serum potassium levels and the occurrence of ventricular arrhythmias. The results of the current analysis suggest that there is a need for change in our current concepts of the ideal serum potassium levels in patients with AMI.

Nutritional status in patients with ulcerative colitis in Isfahan, Iran

Background:Malnutrition is common among patients with inflammatory bowel disease. The present study aimed to investigate the nutritional status of ulcerative colitis (UC) patients in Isfahan, Iran.Materials and Methods:In this descriptive analytical cross-sectional study, between Dec 2011 and Jun 2012, 99 patients with UC were randomly selected and evaluated. Age, sex, duration of disease, body mass index (BMI) and laboratory parameters recorded for all patients. Nutritional risk index (NRI) was calculated and its association with patients’ variables was assessed with regard to UC disease severity.Results:Twelve patients out of 99 patients had mild UC and 87 patients had moderate to severe UC. Based on the NRI, 90.9% were not malnourished and 9.1% were at moderate to severe risk for malnutrition. Among laboratory parameters only, serum potassium level in patients with moderate to severe UC was significantly higher than those with mild UC (P = 0.017). Other laboratory parameters were similar between patients stratified by US status. Patients age s significantly correlate with serum vitamin D, immunoglobulin a (IgA) and potassium level (P > 0.05), also duration of disease was significantly correlate with Phosphorus (P = 0.024) among laboratory parameters.Conclusion:In studied UC patients, malnutrition risk was based on degree of disease severity. Patients with moderate to severe UC were more at risk for malnutrition compared to the patients with mild UC. Furthermore, among laboratory parameters only serum potassium level was higher among patients with moderate to severe UC compared to others.

Safety of Mineralocorticoid Receptor Antagonists in Patients Receiving Hemodialysis

To evaluate the literature supporting the safe use of mineralocorticoid antagonists (MRAs) in patients with end-stage renal disease who are receiving hemodialysis. A review of the literature was performed using MEDLINE (1950 through week 2 of February 2012) using the key words and MeSH terms mineralocorticoid antagonists, aldosterone antagonists, spironolactone, or eplerenone combined with dialysis, renal disease, or kidney disease. Studies eligible for inclusion evaluated the impact of MRAs on serum potassium levels in patients with end-stage renal disease receiving hemodialysis. Data related to the patient populations and outcomes of interest were extracted from each publication. Ten studies were included in this review (spironolactone, 9; eplerenone, 1) and reported on the impact of MRAs on potassium levels in this population. In aggregate, the studies, with spironolactone doses ranging from 25 mg 3 times/week after dialysis to 300 mg/day and eplerenone doses of 25 mg twice daily, have shown little increases in serum potassium, particularly with the lower doses. The overall incidence of severe hyperkalemia was low. The literature base is limited by significant methodologic weaknesses of the studies, including low patient numbers, short follow-up periods, and lack of a blinded control group. The current literature suggests that MRAs may be used safely in patients with end-stage renal disease receiving hemodialysis, although additional large controlled trials are needed before definitive treatment recommendations can be made.

Clinical features and recovery patterns of acquired non-thyrotoxic hypokalemic paralysis

Objective To report the clinical features and recovery patterns of patients with non-thyrotoxic acquired hypokalemic paralysis. Methods The clinical and laboratory records of 11 consecutive patients with acquired non-thyrotoxic hypokalemic paralysis were reviewed and compared with those of 3 patients with thyrotoxic periodic paralysis (TPP). The causes of potassium wasting were diarrhea (n = 4), alcohol abuse (n = 2), pseudoaldosteronism (n = 2), primary aldosteronism (n = 1), distal renal tubular acidosis associated with Sjögren's syndrome (n = 1) and an unknown cause (n = 1). Results Three of the 11 patients had prominently asymmetric limb weakness, and 2 had predominant upper limb weakness. On admission, mean serum potassium and creatine kinase (CK) levels of patients with acquired hypokalemic paralysis on admission were 1.8 mEq/L and 4,075 U/mL, respectively, and the mean duration between admission and independent walking was 6.8 days (range, 2–31 days). Despite clinical recovery, 10 patients still presented with increased CK levels after several days (mean of maximum levels, 10,519 U/mL). In addition, normalization of serum potassium levels in patients with acquired hypokalemic paralysis patients was much slower compared to that in patients with TPP. One patient with acquired hypokalemic paralysis developed ventricular fibrillation, whereas all 3 patients with TPP had symmetric proximal and lower limb-dominant weakness and exhibited complete recovery from paralysis as well as normalized serum potassium levels within 24 h. Conclusions In patients with acquired non-thyrotoxic hypokalemic paralysis, asymmetric or upper limb-dominant weakness of the extremities is observed. Despite clinical improvement after treatment, normalization of serum potassium and CK levels is often delayed, and therefore, careful monitoring for cardiac and renal complications is required.

77: Outcomes Associated With Serum Potassium Level in Patients With Non-Dialysis Dependent CKD

77: Outcomes Associated With Serum Potassium Level in Patients With Non-Dialysis Dependent CKD

Effect of fludrocortisone acetate on reducing serum potassium levels in patients with end-stage renal disease undergoing haemodialysis

Hyperkalaemia is a commonly encountered problem in dialysis patients with end-stage renal disease (ESRD). The aim of the present study was to assess the effect of fludrocortisone acetate (FCA) on reducing serum potassium levels in haemodialysis (HD) patients with hyperkalaemia. Prospectively, 21 HD patients with hyperkalaemia were enrolled in this study. Patients were divided into two groups, including FCA (0.1 mg/d, n = 13) administration or no treatment (control, n = 8) for 10 months. No changes in dialysis or drug regimens were made during this period. Result. There were no significant differences in the baseline characteristics and biochemical parameters between the two groups (FCA therapy and control). At 10-months after FCA therapy, serum potassium levels were not significantly different between the treatment and control groups [median value (range): 5.2 (4.4-6.0) vs 5.8 (4.8-6.3) mEq/l, P = 0.121]. However, using the Wilcoxon signed ranks test, serum potassium levels were significantly lower at the end of the 10 month time period after FCA therapy compared with serum potassium levels of the pre-treatment period [5.2 (4.4-6.0) vs 6.1 (5.3-6.8), P = 0.01]. The biochemical values, including sodium, chloride, protein, albumin, blood nitrogen, creatinine, interdialytic weight change and blood pressure, did not show significant difference in comparisons between the two groups and pre-and post-FCA therapy period. FCA therapy appears to slightly decrease serum potassium value in hyperkalaemic HD patients. However, these results are insufficient to explain the effectiveness of FCA. Therefore, potentially large-scale studies with increased dose concentrations are needed to minimize the positive potassium balance in hyperkalaemic HD patients.

Effect of Drospirenone on Serum Potassium and Drospirenone Pharmacokinetics in Women With Normal or Impaired Renal Function

This open-label study investigated whether drospirenone, a novel progestin with antimineralocorticoid properties, increases the risk for hyperkalemia in subjects with renal impairment. Women with normal renal function and mild or moderate renal impairment were given drospirenone 3 mg/d for 14 days. Mean serum potassium concentrations did not significantly change during steady-state drospirenone treatment. No difference in drospirenone effects on serum potassium concentrations in subjects with renal insufficiency versus subjects with normal renal function was found. Steady-state pharmacokinetics was similar in subjects with normal renal function and mild renal impairment, whereas, due to results from 1 subject, drospirenone exposure was slightly higher in the moderate renal impairment group. Given the reported tolerability of drospirenone, this small increase in serum drospirenone is not expected to be clinically significant. In conclusion, this study demonstrated that drospirenone has no significant effect on serum potassium levels in patients with mild to moderate renal insufficiency.

Salbutamol Metered-Dose Inhaler With Spacer for Hyperkalemia: How Fast? How Safe?

To determine the efficacy of inhaled salbutamol (rapidly delivered, using a metered-dose inhaler with a spacer device [MDI-S]) in lowering the serum potassium levels in patients with hyperkalemia. A randomized, double-blind, placebo-controlled trial. Seventeen chronic renal failure patients referred to the Nephrology Unit between October 1, 1997 and March 31, 1998 for hemodialysis were randomized. Group 1 received salbutamol followed by a placebo. Group 2 received a placebo followed by salbutamol. Each patient inhaled 1,200 microg salbutamol or a placebo through an MDI-S within 2 min. Blood samples were obtained repeatedly before inhalation and after 1, 3, 5, 10, and 60 min. The pulse rate and blood pressure were repeatedly measured. Insulin levels were examined in a subset of patients (n = 10) before, and 1 and 5 min following inhalation. Salbutamol's known side effects, palpitation, tachycardia tremor, and headache, were recorded. Potassium levels rose after 1 min following the completion of treatment and then decreased steadily thereafter. A rise of > or = 0.1 mEq/L was seen in 10 of 17 patients (59%) during the treatment period and there was no change (0%) seen during the placebo period (p < 0.0001). Within 3 min after inhalation of salbutamol, potassium levels declined as a function of time. Potassium levels in those patients taking the placebo did not change as a function of time (p < 0.001). The difference between the placebo and the salbutamol-treated periods reached significance after 5 min (p < 0.05). The serum glucose levels rose following inhalation of salbutamol, with a significant rise after 3 min. The heart rate rose significantly within the first 5 min following inhalation. Serum insulin levels remained unchanged 1 min after inhalation; however, after 5 min, a significant elevation was detected. Salbutamol inhalation of 1,200 microg, using an MDI-S, has a relatively rapid onset of action that induces a consistent reduction in serum potassium levels, starting 3 to 5 min following delivery. Unexpectedly, a paradoxical elevation was detected in serum potassium levels in the first minutes following inhalation. This effect, although minor (0.15 mEq/L above baseline), may cast some doubt on the role of salbutamol inhalation as the first treatment for excessive hyperkalemia.

Rapid Life-Threatening Hyperkalemia After Addition of Amiloride HC1/Hydrochlorothiazide to Angiotensin-Converting Enzyme Inhibitor Therapy

Study objective: To highlight the dangers of a precipitous rise in serum potassium levels in patients at risk for renal insufficiency, already receiving an angiotensin-converting enzyme (ACE) inhibitor, who are given a potassium-sparing diuretic. Methods: We conducted a retrospective chart review of five patients who were taking the above combination of medications who were seen in our ED with hyperkalemia. Results: All five patients had diabetes and were older than 50 years of age. Except for one patient, they had some degree of renal impairment and all were receiving an ACE inhibitor. Each had amiloride HCl/hydrochlorothiazide added to their therapeutic regimen 8 to 18 days before presenting to our ED with hyperkalemia. Potassium levels were between 9.4 and 11 mEq/L in 4 of the patients; 2 did not respond to resuscitation measures. Conclusion: The concomitant use of ACE inhibitor and potassium-sparing diuretic therapy should be avoided. If impossible, weekly monitoring of both renal function and serum potassium should be performed. In the ED patients who are receiving such a combination should receive immediate ECG monitoring. [Chiu T-F, Bullard MJ, Chen J-C, Liaw S-J, Ng C-J: Rapid life-threatening hyperkalemia after addition of amiloride HCl/hydrochlorothiazide to angiotensin-converting enzyme inhibitor therapy. Ann Emerg Med November 1997;30:612-615.]

Angiotensin-converting enzyme inhibition as a therapeutic principle in Bartter's syndrome

The effect of captopril has been investigated in four patients with Bartter's syndrome treated for 12 weeks. Baseline biochemistry showed normal serum aldosterone (mean 347 pmol.l-1) and a mean serum renin of 217 mU-l-1, and a considerable increase in serum renin during captopril treatment. Serum aldosterone decreased gradually during the study period to about half its initial value. The patients presented with a mean serum potassium of 2.5 mmol.l-1, which rose to 3.4 mmol.l-1 on captopril. Lymphocytes showed a substantial captopril-induced increase in intracellular sodium (from 15 to 22.5 mmol.l-1 on average), but no change in the potassium content. Captopril was well-tolerated. It may be an alternative to potassium-sparing diuretics for maintaining normal serum potassium levels in patients with Bartter's syndrome.

Interaction of the sympathetic nervous system and electrolytes in congestive heart failure

Congestive heart failure is characterized by both disturbances in electrolyte homeostasis and neurohormonal regulation. Total body potassium is reduced, and this reduction bears a modest relation to activation of the sympathetic nervous system and the renin-angiotensin-aldosterone system. Patients with decompensated heart failure show increases in both plasma epinephrine and plasma norepinephrine, whereas patients with chronic stable heart failure usually have an increase only in plasma norepinephrine. High levels of circulating epinephrine may contribute to the development of hypokalemia by activating skeletal muscle and liver membrane β 2-adrenergic receptors, which in turn stimulate intracellular cyclic adenosine monophosphate to activate the membrane-bound Na +K +-adenosine triphosphatase pump. The net result is that potassium flux across the cell membrane from the extracellular to the intracellular space increases, setting the stage for hypokalemia and possibly serious ventricular arrhythmias. Other mechanisms that may contribute to the development of hypokalemia in heart failure include the kaliuresis brought on by excessive levels of aldosterone. Moreover, it is likely that the activity of the sympathetic nervous system in heart failure is facilitated by concomitant activation of the reninangiotensin system. Increased sympathetic nerve activity may then release additional renin from the kidney (by way of a β 2-adrenergic mechanism). Therefore, both the sympathetic nervous system and the adrenal medulla may interact to cause hypokalemia in patients with heart failure. Because hypokalemia is known to predispose patients to ventricular arrhythmias, it may be prudent to aggressively maintain serum potassium levels in patients with heart failure in the range of 4 to 5 mEq/ liter.

Succinylcholine Does Not Increase Serum Potassium Levels in Patients With Acutely Ruptured Cerebral Aneurysms

Succinylcholine-induced hyperkalemia has been reported to occur in many neurological disorders including subarachnoid hemorrhage. The purpose of this study was to compare the effect of succinylcholine on serum potassium levels in patients with ruptured cerebral aneurysms undergoing either early (less than or equal to 4 days; n = 14) or delayed (5-16 days; n = 20) surgery. Thirty-four patients were classified according to the number of days from subarachnoid hemorrhage to surgery. Arterial serum potassium levels were measured after induction of anesthesia but before succinylcholine, and 1, 5, and 10 min after the administration of succinylcholine. The electrocardiogram was continuously monitored. The mean ( +/- SD) increase in serum potassium level of 0.4 +/- 0.2 mmol/L occurred at 10 min but was not statistically significant, nor was there any statistically significant difference in serum potassium levels related to time between subarachnoid hemorrhage and administration of succinylcholine. We found no evidence of succinylcholine-induced hyperkalemia in patients undergoing either early or delayed cerebral aneurysm surgery.

Fluid and Electrolyte Considerations in Diuretic Therapy for Hypertensive Patients With Chronic Obstructive Pulmonary Disease

When a patient with chronic obstructive pulmonary disease (COPD) requires medical therapy for systemic hypertension, a number of special considerations may affect the choice of antihypertensive drug and subsequent management. Thiazide diuretics have no adverse effect on airway function and are the agents of choice for initial therapy. beta-Antagonists are usually considered first-line agents in antihypertensive therapy, but even relatively cardioselective ones may increase airway resistance in patients with obstructive lung diseases, and they should be used with caution, if at all, in such patients. Although potassium-wasting diuretics are the preferred agents for treating hypertension in patients with COPD, they may worsen carbon dioxide retention in hypoventilating patients and potentiate hypokalemia in those receiving corticosteroids. In addition, beta-agonists may substantially lower serum potassium levels in patients already rendered hypokalemic by diuretics. Patients with COPD receiving potassium-wasting diuretics who have chronic respiratory acidosis or are receiving corticosteroids or beta-agonists should undergo close monitoring of electrolyte levels and be considered for therapy with potassium supplements or, preferably, potassium-sparing agents.

Influence of the serum potassium and other electrolytes on the electrocardiogram in diabetic acidosis

1. 1. In a study of forty-five patients with diabetic acidosis the serum potassium level was found to be normal or elevated before therapy and fell to concentrations below normal soon after treatment was instituted. 2. 2. Studies are presented which suggest that the duration of the Q-T interval is influenced for the most part by the level of serum potassium in these patients. 3. 3. There was a significant correlation between the height of the T wave and the blood pH and carbon dioxide tension. 4. 4. The height of the T wave is undoubtedly influenced by the serum potassium level. The relationship is only qualitative and in no sense quantitative. Studies are presented which suggest that only in the presence of prolongation of the Q-T interval, when the S-T segments remain normal in duration, can the height of the T wave be used as a crude means of estimating the serum potassium level in patients who are actively treated for diabetic acidosis. 5. 5. The appearance of a U wave in the electrocardiogram when the serum potassium concentration was below normal is described. Such U waves consistently disappeared during administration of isotonic potassium chloride. 6. 6. Since the configuration in the electrocardiogram in these forty-five patients with diabetic acidosis was consistently related to the level of serum potassium, we believed that this instrument offers a valuable means of following in a crude way the serum potassium level during the treatment of patients with diabetic acidosis.