Assessment of a downsized potassium adsorption filter designed to transfuse neonates.

BACKGROUND: During storage, the potassium level of red blood cell (RBC) components increases, especially after irradiation. Neonates are prone to hyperkalemia, for example, non-oliguric hyperkalemia, so using potassium adsorption filters during transfusion may be helpful. To overcome dilution of RBC components caused by saline priming of existing potassium adsorption filters, a downsized potassium adsorption filter for neonates (PAF-n, Kawasumi Laboratories Inc., Tokyo, Japan) was developed. STUDY DESIGN AND METHODS: To assess the performance of PAF-n, its adsorption efficiency and RBC recovery rate were evaluated by testing pre-filtration and serial post-filtration (0-30 mL, 30-60 mL, 60-90 mL, and 90-120 mL) samples from 8 RBC components. RESULTS: The average potassium adsorption rate of the PAF-n was 90.5% ± 0.78%, and never less than 89.0% in any of 8 RBC components. RBC recovery rates were 99.3% ± 1.12%. CONCLUSION: The PAF-n showed an effective potassium ability with negligible RBC dilution.

The value of maintaining normokalaemia and enabling RAASi therapy in chronic kidney disease.

BACKGROUND: People with chronic kidney disease (CKD) are at an increased risk of developing hyperkalaemia due to their declining kidney function. In addition, these patients are often required to reduce or discontinue guideline-recommended renin-angiotensin-aldosterone system inhibitor (RAASi) therapy due to increased risk of hyperkalaemia. This original research developed a model to quantify the health and economic benefits of maintaining normokalaemia and enabling optimal RAASi therapy in patients with CKD. METHODS: A patient-level simulation model was designed to fully characterise the natural history of CKD over a lifetime horizon, and predict the associations between serum potassium levels, RAASi use and long-term outcomes based on published literature. The clinical and economic benefits of maintaining sustained potassium levels and therefore avoiding RAASi discontinuation in CKD patients were demonstrated using illustrative, sensitivity and scenario analyses. RESULTS: Internal and external validation exercises confirmed the predictive capability of the model. Sustained potassium management and ongoing RAASi therapy were associated with longer life expectancy (+ 2.36 years), delayed onset of end stage renal disease (+ 5.4 years), quality-adjusted life-year gains (+ 1.02 QALYs), cost savings (£3135) and associated net monetary benefit (£23,446 at £20,000 per QALY gained) compared to an absence of RAASi to prevent hyperkalaemia. CONCLUSION: This model represents a novel approach to predicting the long-term benefits of maintaining normokalaemia and enabling optimal RAASi therapy in patients with CKD, irrespective of the strategy used to achieve this target, which may support decision making in healthcare.

Development of a health economic model to evaluate the potential benefits of optimal serum potassium management in patients with heart failure.

AIMS: Patients with heart failure are at increased risk of hyperkalemia, particularly when treated with renin-angiotensin-aldosterone system inhibitor (RAASi) agents. This study developed a model to quantify the potential health and economic value associated with sustained potassium management and optimal RAASi therapy in heart failure patients. MATERIALS AND METHODS: A patient-level, fixed-time increment stochastic simulation model was designed to characterize the progression of heart failure through New York Heart Association functional classes, and predict associations between serum potassium levels, RAASi use, and consequent long-term outcomes. Following internal and external validation exercises, model analyses sought to quantify the health and economic benefits of optimizing both serum potassium levels and RAASi therapy in heart failure patients. Analyses were conducted using a UK payer perspective, independent of costs and utilities related to pharmacological potassium management. RESULTS: Validation against multiple datasets demonstrated the predictive capability of the model. Compared to those who discontinued RAASi to manage serum potassium, patients with normokalemia and ongoing RAASi therapy benefited from longer life expectancy (+1.38 years), per-patient quality-adjusted life year gains (+0.53 QALYs), cost savings (£110), and associated net monetary benefit (£10,679 at £20,000 per QALY gained) over a lifetime horizon. The predicted value of sustained potassium management and ongoing RAASi treatment was largely driven by reduced mortality and hospitalization risks associated with optimal RAASi therapy. LIMITATIONS: Several modeling assumptions were made to account for a current paucity of published literature; however, ongoing refinement and validation of the model will ensure its continued accuracy as the clinical landscape of hyperkalemia evolves. CONCLUSIONS: Predictions generated by this novel modeling approach highlight the value of sustained potassium management to avoid hyperkalemia, enable RAASi therapy, and improve long-term health economic outcomes in patients with heart failure.

A simple protocol to improve safety and reduce cost in hemodialysis patients undergoing elective surgery.

BACKGROUND: When patients with end-stage renal disease (ESRD) miss their routine intermittent hemodialysis (IHD), electrolyte abnormalities and volume overload often occur. An institutional protocol to ensure that patients receiving IHD have elective surgeries scheduled within 24 hours after their dialysis may reduce procedural delays or cancellations caused by hyperkalemia and hypervolemia after a missed IHD session. The effect of this protocol was evaluated. METHODS: A retrospective chart review was performed for ESRD patients receiving IHD who underwent surgery from 6 months before to 6 months after the institutional protocol was implemented. Preoperative potassium values, timing of IHD relative to surgery, and the nature of surgery (elective or emergent) were documented. The percentage of patients having IHD more than 24 hours before their elective surgery was compared before and after protocol implementation. Average potassium values were compared when IHD occurred within 24 hours vs. more than 24 hours, using t test analysis. Cost associated with delay and cancellation for IHD was also explored. RESULTS: Of the 15,799 cases performed, 190 involved ESRD patients receiving IHD. Before the protocol, 32.1% of elective cases (n = 17) involved patients scheduled for surgery more than 24 hours after IHD vs. 12.0% (n = 6) after the protocol. Preoperative potassium values were less when patients underwent IHD within 24 hours than at more than 24 hours (mean [SD], 4.32 [0.6] mEq/L vs 4.63 [0.8] mEq/L; P = .03). CONCLUSIONS: The simple scheduling policy is effective at reducing both cost and unnecessary perioperative risks for patients.

Serum potassium monitoring for users of ethinyl estradiol/drospirenone taking medications predisposing to hyperkalemia: physician compliance and survey of knowledge and attitudes.

PURPOSE: Yasmin-28 [ethinyl estradiol 0.03 mg/drospirenone 3 mg (EE/DRSP)] contains drospirenone, a progestin component that possesses antimineralocorticoid activity with a potassium-sparing diuretic effect similar to that in spironolactone. Product labeling recommends potassium monitoring in the first month of use for women concurrently receiving medication that may increase serum potassium. METHODS: We evaluated compliance with this recommendation by measuring monitoring around the date of oral contraceptive (OC) initiation in women who received EE/DRSP while being treated with medications predisposing to hyperkalemia and in similar women who received other OCs. Because preliminary analyses indicated incomplete compliance, we surveyed physicians who prescribed EE/DRSP to women receiving drugs predisposing to hyperkalemia on their knowledge and attitudes with regard to the recommendation. We conducted this study using data from the Ingenix Research Datamart, which includes insurance claims for reimbursement for medical services and prescription medications for approximately 8,000,000 members of a large nationally dispersed health plan. We used claims for pharmacy dispensings of prescription medications to identify all women aged 10-59 years old who initiated EE/DRSP or other OCs during the first 3 years of EE/DRSP availability (July 2001 to June 2004). The frequency of potassium monitoring was measured by identifying claims for serum potassium tests. We conducted a telephone survey of 58 physicians who had prescribed EE/DRSP up to June 2003 to women who received concomitant hyperkalemic drugs. RESULTS: Although potassium monitoring was generally more frequent among EE/DRSP initiators receiving concomitant hyperkalemic drugs than among other OC initiators receiving similar medications, only 40% of 466 EE/DRSP initiators with concurrent hyperkalemic treatment had potassium tests. More than 98% of surveyed physicians were aware of the potassium-sparing property of EE/DRSP. Compared with physicians whose patients had potassium tests, physicians of patients without such tests were more likely to disagree with the recommendation for users of angiotensin-converting enzyme inhibitors, angiotensin II receptor antagonists, heparin and nonsteroidal anti-inflammatory drugs. Patient barriers and health plan restrictions were other factors possibly contributing to noncompliance. CONCLUSION: This study demonstrates incomplete physician compliance with a labeling recommendation of potassium monitoring for initiators of EE/DRSP receiving concomitant therapy predisposing to hyperkalemia. The limited compliance was likely due to a combination of selective physician acceptance of the recommendations and specific patient and health plan barriers to testing.

Aldosterone blockade in post-acute myocardial infarction heart failure.

Development of heart failure (HF) or left ventricular systolic dysfunction (LVSD) significantly increases mortality post acute myocardial infarction (AMI). Aldosterone contributes to the development and progression of HF post AMI, and major guidelines now recommend aldosterone blockade in this setting. However, lack of practical experience with aldosterone blockade may make clinicians hesitant to use these therapies. This review is based on a consensus cardiology conference that occurred in May 2005 (New York City) concerning these topics. Potential barriers to the use of aldosterone blockade are discussed and an algorithm for appropriate in-hospital pharmacologic management of AMI with LVSD and/or HF is presented.