Physical Compatibility of Sodium Glycerophosphate and Calcium Gluconate in Pediatric Parenteral Nutrition Solutions

Background: The solubility of inorganic calcium and phosphate in parenteral solutions can be complicated in pediatrics due to the dosing of calcium and phosphorus at the saturation point. The purpose of this study was to test the solubility of sodium glycerophosphate (NaGP) with calcium gluconate in pediatric parenteral nutrition (PN) solutions. Methods: Five PN solutions were compounded by adding calcium gluconate at 10, 20, 30, 40, and 50 mEq/L and corresponding concentrations of NaGP at 10, 20, 30, 40, and 50 mmol/L. Each of the 5 solutions was compounded using 1.5% and 4% amino acids, cysteines, and lipids. Compatibility was evaluated by visual inspection (precipitation, haze, and color change). Solutions were evaluated microscopically for any microcrystals and measured by a turbidimeter for changes in turbidity. Solutions were further analyzed using United States Pharmacopeia 788 standards. Six hundred seventy‐one PN solutions were compounded at various concentrations and evaluated for visual stability. Results: Compatibility testing showed no changes in the PN solution in any of the concentrations tested. Microscopically, no microcrystals were detected. The turbidimeter measurements had changes of ≤0.14 nephelometric turbidity units for all test solutions. There were no visual changes in any of the 671 PN solutions. Conclusion: It is recommended that NaGP replace sodium phosphate in PN solutions. This would eliminate the concern of calcium and phosphorus precipitation and the need of any saturation curves.     

Electrocardiographic changes associated with β-blocker toxicity

Study objective: We sought to characterize the ECG changes associated with symptomatic β-blocker overdose. Methods: The study population consisted of a prospective cohort of patients reporting to 2 regional poison centers with β-blocker overdose. Each patient received an ECG on presentation and a structured follow-up. The inclusion criteria for symptomatic overdose included heart rate of less than 60 beats/min or systolic blood pressure of less than 90 mm Hg; symptoms consistent with decreased end-organ perfusion; therapeutic intervention with cardioactive medication; and corroboration by 2 of the authors that this was a clear-cut case of symptomatic β-blocker overdose with cardiovascular toxicity. Exclusion criteria included cardioactive coingestants, age younger than 6 years, and no available ECG. Results: Of 167 patients, 13 were determined to have symptomatic exposures. First-degree heart block (>200 ms) was the most common ECG finding (10/12) and also had the greatest likelihood ratio (5.31) when comparing those with symptomatic exposures with those with asymptomatic exposures. Comparing the asymptomatic with the symptomatic groups, the mean PR interval was 167 ms (95% confidence interval [CI] 162 to 171 ms) versus 216 ms (95% CI 193 to 238 ms), the mean QRS interval was 89 ms (95% CI 87 to 91 ms) versus 112 ms (95% CI 92 to 132 ms), the mean QTc interval was 422 ms (95% CI 417 to 428) versus 462 ms (95% CI 434 to 490 ms), and the mean heart rate was 72 beats/min (95% CI 69 to 74 beats/min) versus 66 beats/min (95% CI 59 to 73 beats/min). Two cases of symptomatic acebutolol exposure appeared unique by demonstrating disproportionate prolongation of the QTc interval, an RaVR height of 3 mm or greater, and associated ventricular tachydysrhythmia. Conclusion: The majority of clinically significant β-blocker intoxications demonstrate negative dromotropic effects on ECG. Several ECG differences in acebutolol intoxication might reflect unique pathophysiologic processes relative to other β-blockers. [Ann Emerg Med. 2002;40:603-610.]     

Acute and chronic pulmonary emboli

Opinion statement  

Do nonsteroidal anti-inflammatory drugs interfere with blood pressure control in hypertensive patients?

Exacerbation of hypertension by nonsteroidal anti-inflammatory drugs in hypertensive patients remains controversial among physicians and investigators. Because of the many differences among studies of oral nonsteroidal anti-inflammatory drugs and blood pressure control in patients with hypertension, the authors critically evaluated the published clinical evidence on this subject using standardized methodologic criferia. A search of the literature from 1965 to 1986 identified 31 relevant studies, of which only eight were double-blind randomized controlled trials that provided the most clinically useful information. Of these eight best-designed studies, five of the six that studied indomethacin concluded that it may interfere with antihypertensive effectiveness in selected patients with treated, stable hypertension. The remaining double-blind randomized studies included comparisons of other nonsteroidal anti-inflammatory drugs. Their limited results suggest that sulindac is less likely than piroxicam, naproxen or indomethacin to cause an attenuation of antihypertensive therapy. More research on this subject is needed, with greater attention to methodologic details and identification of predisposing risk factors for impairment of blood pressure control by nonsteroidal anti-inflammatory drugs. Received from the Department of Internal Medicine, University of Cincinnati, Medical Center, and the Department of Pharmacy. University Hospital, Cincinnati, Ohio.     

Comparing standard care with a physician and pharmacist team approach for uncontrolled hypertension

OBJECTIVE: To assess the effect of a physician and pharmacist teamwork approach to uncontrolled hypertension in a medical resident teaching clinic, for patients who failed to meet the recommended goals of the fifth Joint National Commission on Detection, Evaluation and Treatment of High Blood Pressure. HYPOTHESIS: Physician and pharmacist teamwork can improve the rate of meeting national blood pressure goals in patients with previously uncontrolled hypertension. DESIGN: A single-blinded randomized controlled trial lasting 6 months. SETTING: A primary care outpatient teaching clinic. PATIENTS: A sample of 95 adult hypertensive patients who failed to meet national blood pressure goals based on three consecutive visits over a 6-month period. INTERVENTION: Patients were randomly assigned to a control arm of standard medical care or to an intervention arm in which a physician and pharmacist worked together as a team. MAIN RESULTS: At study completion, the percentage of patients achieving national goals due to intervention was more than double the percentage in the control arm (55% vs 20%, p < .001). Systolic blood pressure declined 23 mm Hg in the intervention arm versus 11 mm Hg in the control arm (p < .01). Diastolic blood pressure declined 14 and 3 mm Hg in the intervention and control arms, respectively (p < .001). The intervention worked equally as well in men and women and demonstrated noticeable promise in a minority of mixed-ancestry Hawaiians in whom hypertension is of special concern. CONCLUSIONS: Patients who fail to achieve national blood pressure goals under standard outpatient medical care may benefit from a program that includes a physician and pharmacist teamwork approach. The views expressed in this article are those of the authors and do not reflect the official policy or position of the Queen’s Medical Center. This work was supported by a grant from the Queen’s Medical Center, Honolulu, Hawaii and by a Research Centers in Minorities Institutions Award (P20 RR 11091) from the National Institutes of Health.