Final answer:
The resulting concentration of penicillin in the saline after adding 10 ml of a 25 mg/ml penicillin solution to a 100 ml bottle is approximately 2.27 mg/ml. The specific volume for the maintenance dose can then be calculated based on a patient's weight, using the concentration for the required 1 mg/kg/hr dosage.
Step-by-step explanation:
When 10 ml of a 25 mg/ml penicillin solution is added to a 100 ml bottle of saline, the first step is to calculate the total amount of penicillin being added. This is done by multiplying the volume of penicillin solution by its concentration: 10 ml × 25 mg/ml = 250 mg of penicillin.
After adding the penicillin solution to the saline, the total volume of the resulting solution is the sum of the volumes of the two solutions: 10 ml + 100 ml = 110 ml. Then, to find the concentration of penicillin in the new solution, we divide the total amount of penicillin by the total volume of the solution: 250 mg / 110 ml = approximately 2.27 mg/ml.
Given the recommended maintenance dose of 1 mg/kg/hr by injection, it's important to note that this dosage depends on the patient's body weight. The concentration of the diluted penicillin solution (about 2.27 mg/ml) can be used to calculate the specific volume to be administered every hour based on the patient's weight.