Local anesthetic dosages: a new look at an old drug.
You have administered 4 carpules of 2% Lidocaine with 1:100,000 to a hypertensive patient. Which amount below represents the correct dose of epinephrine the patient received (expressed in micrograms)?
That is correct!
Explanation: An epinephrine concentration of 1:100,000 is 10 mcg (mcg = micrograms) of epinephrine per ml. To simplify the math, let's over estimate the volume at 2 cc per dental carpule rather than the peculiar dose of 1.7 or 1.8 cc. This is safe practice for estimating dosages. Each carpule of local anesthetic with epinephrine in a 1:100,000 concentration has 20 mcg of epinephrine per carpule. See below:
10 mcg/ml x 2.0 cc/carpule = 20 mcg epinephrine/carpule
4 carpules x 20 mcg= 80 mcg epinephrine
There is no maximum dose of epinephrine recommended. However it is prudent to have a baseline blood pressure and monitor the blood pressure during the appointment. By way of comparison, the epinephrine dose for treatment of anaphylaxis is 300mcg.
No matter how you score, click the link below to check out Southwest Oral Surgery's new Continuing Education course on local anesthetics and safe dosages.