A nurse is assisting with the care of a school-age child who has respiratory failure due to pneumonia. Which of the following positions should the nurse encourage to allow maximal lung expansion?

Choice A reason: Crackles auscultated over the client's lung fields are not a sign of pleural effusion. Crackles are abnormal breath sounds that indicate fluid or secretions in the alveoli. They can be heard in conditions such as pneumonia, heart failure, or pulmonary edema.

Choice B reason: Crepitus palpated on the client's chest is not a sign of pleural effusion. Crepitus is a crackling sensation that occurs when air leaks into the subcutaneous tissue. It can be felt in conditions such as pneumothorax, chest trauma, or chest surgery.

Choice C reason: Substernal retractions noted on the client's chest are not a sign of pleural effusion. Substernal retractions are inward movements of the chest wall below the sternum that indicate increased respiratory effort. They can be seen in conditions such as asthma, bronchiolitis, or croup.

Choice D reason: Dullness percussed over the client's lung fields is a sign of pleural effusion. Dullness is a flat sound that indicates the presence of a solid or liquid mass in the thoracic cavity. It can be detected in conditions such as pleural effusion, atelectasis, or consolidation.

The correct answer is c. Muscle weakness.

Choice A: Hypertension

Reason: Hypertension, or high blood pressure, is not a typical manifestation of hypokalemia. Hypokalemia primarily affects muscle function and the nervous system. While potassium imbalances can influence blood pressure, hypertension is more commonly associated with hyperkalemia (high potassium levels) rather than hypokalemia.

Choice B: Cerebral Edema

Reason: Cerebral edema, which is swelling of the brain, is not a known manifestation of hypokalemia. Hypokalemia affects muscle and nerve function, but it does not directly cause cerebral edema. This condition is more related to severe head injuries, infections, or other medical conditions.

Choice C: Muscle Weakness

Reason: Muscle weakness is a common and significant manifestation of hypokalemia. Potassium is crucial for muscle function, and low levels can lead to muscle weakness, cramps, and even paralysis in severe cases. This is because potassium helps in the transmission of nerve signals to muscles, and a deficiency disrupts this process.

Choice D: Hyperactive Bowel Sounds

Reason: Hyperactive bowel sounds are not typically associated with hypokalemia. In fact, hypokalemia can lead to decreased bowel motility, resulting in symptoms like constipation or ileus (a condition where the intestines do not move properly). This is due to the role of potassium in muscle contractions, including those in the digestive tract.