An 18-month-old child returned from the cardiac cath lab 1/2 hour ago. The child wakes up and begins crying. The nurse notices that the pressure dressing is becoming saturated with blood. The nurse's first action should be to:

Choice A reason: Increased stroke volume is not a correct answer as it means that the heart pumps more blood with each contraction. This would result in increased blood pressure and perfusion, not cool extremities, weak pulses, and low urine output.

Choice B reason: Cardiac arrhythmia is not a correct answer as it means that the heart beats irregularly or abnormally. This can cause palpitations, chest pain, or fainting, but not necessarily cool extremities, weak pulses, and low urine output.

Choice C reason: Decreased cardiac output is a correct answer as it means that the heart pumps less blood than the body needs. This can result from a ventricular septal defect, which causes blood to shunt from the left ventricle to the right ventricle, reducing the amount of oxygenated blood that reaches the tissues. This can cause cool extremities, weak pulses, and low urine output, as well as fatigue, poor growth, and shortness of breath.

Choice D reason: Cyanosis is not a correct answer as it means that the skin, lips, or nails turn blue due to low oxygen levels in the blood. This can occur in some cases of ventricular septal defect, especially if there is pulmonary hypertension or a reversal of the shunt. However, cyanosis is not a direct cause of cool extremities, weak pulses, and low urine output.

Choice A reason: This statement is correct, as asking about the child's contacts over the last three weeks can help the nurse identify the possible source of infection and the risk of transmission. Rubella is a viral infection that spreads through respiratory droplets or direct contact with an infected person. The incubation period of rubella is 14 to 21 days, meaning that the child could have been exposed to the virus up to three weeks before developing symptoms.

Choice B reason: This statement is incorrect, as asking about the child's immunizations is not the most effective way to determine how the child was exposed to the virus. Although immunization can prevent rubella infection, it is not 100% effective, and some children may still get the disease despite being vaccinated. The nurse should also consider other factors, such as the child's medical history, travel history, and exposure to other people with rash or fever.

Choice C reason: This statement is incorrect, as asking about the medications given to the child is not the most effective way to determine how the child was exposed to the virus. Medications can help relieve the symptoms of rubella, such as fever, rash, or joint pain, but they do not affect the transmission or the course of the infection. The nurse should focus on the epidemiological aspects of the disease, such as the mode of transmission, the incubation period, and the contagious period.

Choice D reason: This statement is incorrect, as asking about the onset of the rash is not the most effective way to determine how the child was exposed to the virus. The rash of rubella usually appears 14 to 17 days after exposure, and lasts for about three days. However, the child can be contagious from seven days before to seven days after the rash appears, meaning that the child could have been exposed to the virus up to four weeks before or after the rash. The nurse should ask about the child's contacts during this period, not just the rash.