A 9-year-old child who weighs 66 lb is to receive gentamicin sulfate 2 mg/kg/dose every 8 hours for an Escherichia coli urinary tract infection. How many mg per dose should this child receive? (Enter numeric value only.)
The Correct Answer and Explanation is:
To determine the correct dosage of gentamicin sulfate for the 9-year-old child weighing 66 lb, we first need to convert the weight from pounds to kilograms, as the medication dosage is specified in mg per kg of body weight.
- Convert pounds to kilograms:
- The conversion factor is 1 kg = 2.2 lb.
- Therefore, to convert 66 lb to kg: Weight in kg=66 lb2.2 lb/kg≈30 kg\text{Weight in kg} = \frac{66 \, \text{lb}}{2.2 \, \text{lb/kg}} \approx 30 \, \text{kg}Weight in kg=2.2lb/kg66lb≈30kg
- Calculate the dose in mg:
- The prescribed dosage is 2 mg/kg/dose.
- Now, multiply the child’s weight in kg by the dosage: Dose=2 mg/kg×30 kg=60 mg\text{Dose} = 2 \, \text{mg/kg} \times 30 \, \text{kg} = 60 \, \text{mg}Dose=2mg/kg×30kg=60mg
Thus, the child should receive 60 mg of gentamicin sulfate per dose.
Explanation of the Calculation Process
Understanding dosage calculations is critical in pediatric nursing, as children often require medications adjusted for their weight and age. In this scenario, the child’s weight was given in pounds, necessitating a conversion to kilograms, which is the standard unit for medication dosages in clinical practice.
Using the conversion factor (1 kg = 2.2 lb), the weight of 66 lb was converted to approximately 30 kg. This step is crucial, as administering medication based on an incorrect weight could lead to underdosing or overdosing, potentially harming the child.
Next, the dosage was calculated using the formula: dosage = mg/kg × weight (kg). Here, the prescribed dosage of 2 mg/kg was multiplied by the child’s weight of 30 kg, resulting in a total of 60 mg. This calculation ensures that the child receives the appropriate amount of medication to effectively treat the urinary tract infection caused by Escherichia coli.
In summary, ensuring accurate dosage calculations is vital in nursing to promote safe and effective patient care, especially in vulnerable populations like children. The calculated dose of gentamicin sulfate is thus 60 mg per administration.