A child with asthma has the following medication ordered: Theophylline 4 mg/kg/dose every 6 hrs. The child weighs 4.69 kg. Calculate the appropriate dose.

Infusion rate (mL/hour) = Total volume (mL) / Total time (hours)

Given:

Child's weight: 10 kg

Ordered volume: 40 mL/kg

Total time: 4 hours

First, calculate the total volume of Lactated Ringer's solution needed:

Total volume = 40 mL/kg × 10 kg = 400 mL

Then, divide the total volume by the total time to find the infusion rate:

Infusion rate = 400 mL / 4 hours = 100 mL/hour

A. Overriding aorta: In Tetralogy of Fallot, the aorta is positioned over the ventricular septal defect (VSD), rather than solely over the left ventricle as it would be in a normal heart. This is called overriding aorta, which allows blood from both the right and left ventricles to enter the aorta.

B. Pulmonary stenosis: This is a critical component of Tetralogy of Fallot. Pulmonary stenosis refers to narrowing of the pulmonary valve or the area just below it, which restricts blood flow from the right ventricle to the pulmonary artery. This results in decreased blood flow to the lungs for oxygenation.

C. Left ventricular hypertrophy: This choice is not typically associated with Tetralogy of Fallot. Left ventricular hypertrophy refers to an enlargement or thickening of the muscular wall of the left ventricle of the heart. It is often seen in conditions where the left ventricle has to work harder to pump blood, such as in hypertension or aortic stenosis, but it is not a characteristic feature of Tetralogy of Fallot.

D. Ventricular septal defect: This defect is one of the four components of Tetralogy of Fallot. A ventricular septal defect (VSD) is a hole in the septum, the muscular wall that separates the left and right ventricles of the heart. In Tetralogy of Fallot, the VSD allows oxygen-poor blood from the right ventricle to flow directly into the left ventricle and out to the body.