What is the correct method to calculate the local anesthetic dosage for an 18-year-old teenager weighing 120 lbs?

The method of calculating local anesthetic dosage involves using the patient's body weight to ensure that the dosage remains within the safe limits established by the maximum recommended dose (MRD) for the specific anesthetic being used.

In this case, the correct approach is to multiply the patient's body weight by the MRD per pound. This method takes the patient's specific weight into account and allows for an accurate calculation of the maximum safe dose of local anesthetic. For example, if the MRD for a certain anesthetic is defined in mg/lb, calculating the dose by multiplying the patient's weight (120 lbs) by this MRD ensures that the total dosage administered does not exceed the recommended safe level, thus minimizing the risk of toxicity or adverse effects.

The other methods suggested would not yield an appropriate or safe dosage. For instance, merely adding the patient's weight to the MRD would not provide a clinically relevant or calculable dosage. Subtracting the patient's weight from the MRD is also illogical, as it would yield a negative dosage, which is clinically inappropriate. Lastly, multiplying the patient's age by the MRD does not take into account the patient's body weight, which is essential for determining the appropriate dosage of local anesthetic.

Thus, option B