A physician ordered magnesium sulfate 2 grams per hour for a maintenance dose. There are 40 grams of magnesium sulfate in 1 liter of lactated Ringers solution.
What is the rate per hour to administer the maintenance dose?

This answer is correct because BSA is the most accurate method for calculating the child's dose from the adult dose¹². BSA takes into account the child's weight and height, and reflects the physiological function and organ growth of the child beter than weight alone¹. BSA can be calculated using a nomogram or a formula based on the child's weight and height¹. The child's dose can then be calculated by multiplying the adult dose by the ratio of the child's BSA to the average adult BSA (1.73 m2)¹. For example:

Child dose by BSA = (mg/day) = Adult Dose in mg/day x BSA in m2 / 1.73

OR

Child dose by BSA = (mg/day) = Adult Dose in mg/m2 x BSA in m2

The other options are not correct because they are not accurate methods for calculating the child's dose from the adult dose. Actual body weight and ideal body weight may not account for individual variations in pharmacokinetics, pharmacodynamics, or clinical response. Actual body height is not a reliable indicator of drug dosage, as it does not reflect the body mass or organ function of the child.

This statement is correct because the abdomen has a large surface area and a good blood supply, which allows for a consistent and predictable absorption of insulin. Insulin is a hormone that regulates blood glucose levels and needs to be delivered in precise doses to avoid complications such as hypoglycemia (low blood glucose) or hyperglycemia (high blood glucose).

The abdomen is also easy to access and has less variation in fat thickness, which reduces the risk of injecting into the muscle or the skin instead of the subcutaneous tissue. The subcutaneous tissue is the layer of fat and connective tissue below the skin and above the muscle, where insulin injections are given.

The other statements are not correct because they do not explain why the abdomen is the preferred site for subcutaneous insulin injections or they contain false information.

a.It is the least painful location for this injection. This statement is false because pain is subjective and depends on many factors, such as the type and size of the needle, the technique and speed of injection, the temperature and viscosity of the insulin, and the individual's pain tolerance and sensitivity. The abdomen may not be the least painful location for everyone, and some people may prefer other sites, such as the arms, thighs, or butocks.
b.There are fewer insulin side effects when given in this site. This statement is false because insulin side effects are not related to the site of injection, but to the dose, type, and timing of insulin, as well as the individual's response to insulin and other factors, such as diet, exercise, stress, illness, and medications. Insulin side effects may include hypoglycemia, weight gain, allergic reactions, lipodystrophy (changes in fat tissue), or edema (swelling).
c.It causes less bruising at the site. This statement is false because bruising is caused by bleeding under the skin due to damage to blood vessels during injection. Bruising can occur at any site of injection and depends on many factors, such as the type and size of the needle, the technique and speed of injection, the pressure applied after injection, the individual's clotting ability and blood thinning medications, and the presence of any underlying conditions that affect blood vessels or circulation.