Ask Us > Obesity and max dosing

Hi,

I'm putting together a lipid rescue kit with instructions for our ORs and ED. We have a large percentage of morbidly obese patients. I've read your previous replies regarding 10-12 mL/kg ideal body mass or lean body weight. Which calculation do you propose to use? As pharmacists, we typically use an adjusted body weight for drugs with large volume of distribution and an ideal body weight (2.3 x in >5 ft + 45.5 for females or 50 for males) for drugs that mostly stay in the bloodstream. Since lipid is fat soluble (obviously), I would think more of an adjusted body weight would be appropriate.
Keeping in mind that I have patients in the 150-200 kg range, the bolus dose of 1.5 mL/kg could exceed 250 mL (which incidentally cannot be given over 1 minute as the protocol recommends). Should we cap the dose at all? What is the largest patient this was used on that was effective and what dose was used?

Thank you!
February 19, 2014 | Unregistered CommenterKatie Hiles, Pharm.D.
Hi Katie,
this is an important topic. In short, I'm not certain of the best correction to use, and I don't think it matters much as long as 1) a sufficient dose is given by bolus to establish a sizeable lipid bulk phase in the plasma and 2) you don't massively overload the patient with lipid. I prefer to for most adults of a normal or supranormal size to use a 100mL bolus, assuming an ideal body mass of 70kg. I would correct this for adult patients who are very small (eg a dwarf) or NBA/NFL-size based on roughly their '%' normal size; for instance, a 35kg dwarf would get half the dose, a 140kg muscle man might get almost 200mL initially . I realized this seems to violate the pharmacists preference for precision, but these doses are not precise or exact. Use common sense and don't give a morbidly obese patient a dose based on their weight. Yes, there is also an upper limit. I would cap the dose at ~10-12 mL/(lean or ideal mass in kg) over the first 30 min. Good luck!
March 13, 2014 | Registered Commenter[Guy Weinberg]