In this episode I’ll:
1. Discuss an article about using adjusted body weight for heparin dosing in obese patients.
2. Answer the drug information question “How long is glucose therapy required after using high-dose insulin for beta-blocker or calcium channel blocker overdose?”
3. Share a resource for studying intensive care topics.
Book reviews on Amazon help potential readers decide whether the book is for them. If you have purchased my A Pharmacist’s Guide to Inpatient Medical Emergencies – thank you! I would really appreciate if you would take a moment to leave a review on Amazon.
Article
Evaluation of heparin dosing based on adjusted body weight in obese patients
Lead author: Jingyang Fan
Published in American Journal of Health-System Pharmacy October 2016
Background
Weight-based heparin dosing can lead to exceptionally high initial heparin doses in obese patients. The authors of this study sought to determine whether heparin dosing based on adjusted body weight (BWAdj) instead of actual body weight (ABW) can lead to faster achievement of therapeutic activated partial thromboplastin time (aPTT) values in obese patients
Methods
The study looked at a retrospective cohort of patients who received heparin before and after the implementation of a heparin protocol using adjusted body weight. The primary outcome was the percentage of first aPTT values within the target range. Secondary outcomes were the average time to the first aPTT value within the target range and the rate of clinically significant bleeding.
Results
The difference in the rate of first aPTT values within the target range was not significant between groups. An in-range aPTT was obtained at an average of 14 hours when adjusted body weight was used compared to 24 hours when actual body weight was used. This difference was statistically significant.
When actual body weight was used, obese patients had an 11% rate of significant bleeding compared to just 1% for non-obese patients. When adjusted body weight was used, the rate of bleeding did not differ between obese and non-obese patients.
Conclusion
The authors concluded:
The percentages of first aPTT values in the targeted range did not differ significantly in obese and nonobese patients before and after protocol implementation. The use of BWAdj for dose calculation in obese patients was associated with faster achievement of an aPTT value in the target range.
Discussion
While this study took place in a single center, it is congruent with the results of other studies which suggest that lowering the initial dose of heparin in obese patients can still lead to acceptable time to first aPTT in the target range. If your heparin nomogram does not make any adjustments in the dose for obese patients, it may be time to reconsider.
Drug information question
Q: How long is glucose therapy required after using high-dose insulin for beta-blocker or calcium channel blocker overdose?
A: Up to 24 hours.
Insulin infusion at doses of 1 unit/kg/hour or higher is effective for the treatment of beta-blocker or calcium channel blocker overdose. Despite using large doses of a dangerous medication, high dose insulin therapy is well-tolerated. Glucose administration is often necessary during high dose insulin therapy to maintain euglycemia. According to an excellent review article in the journal Clinical Toxicology, supplemental glucose administration may be necessary for up to 24 hours after stopping high dose insulin therapy.
Resource
Dr. Paul Young created 355 mind maps to help study for intensive care exams. The mind maps are available for free at the Wellington ICU website. Mind mapping is a powerful tool to help remember and organize large amounts of information.
If you like this post, check out my book – A Pharmacist’s Guide to Inpatient Medical Emergencies: How to respond to code blue, rapid response calls, and other medical emergencies.
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