A nurse is checking the forearm of a client who received a tuberculin skin test 48 hr ago. Which of the following findings at the injection site should indicate to the nurse a positive result?

A. "Instruct the client's visitors not to operate the PCA pump.” Only the client should press the PCA button to self-administer medication. Allowing visitors or family members to press the button ("PCA by proxy") increases the risk of over-sedation, respiratory depression, and opioid toxicity. The nurse should reinforce to visitors that only the client should control medication delivery based on their own pain level.

B. "Check the client's pain level every 8 hours." Pain assessment should be performed more frequently than every 8 hours when a client is receiving morphine PCA. Pain, sedation level, and respiratory status should be monitored every 1–2 hours initially and then at regular intervals as determined by hospital protocol to ensure effective pain management and prevent complications such as respiratory depression.

C. "Diarrhea is an adverse effect of morphine PCA." Morphine is an opioid analgesic that commonly causes constipation, not diarrhea. Opioids slow gastric motility, which can lead to delayed bowel movements, bloating, and discomfort. Clients on long-term opioid therapy often require stool softeners or laxatives to prevent opioid-induced constipation.

D. "Using morphine PCA increases the client's risk of toxicity." PCA pumps are designed with preset dose limits and lockout intervals to prevent overdose. While there is a risk of opioid toxicity if the system is misused (e.g., PCA by proxy or improper settings), PCA is actually safer than traditional opioid administration methods because it allows for precise dosing and patient-controlled pain management. Proper monitoring helps prevent complications.

A. Baker's yeast. The hepatitis B vaccine is contraindicated in individuals with a severe allergy to baker’s yeast. This is because the vaccine is produced using Saccharomyces cerevisiae (baker’s yeast), which can trigger an allergic reaction in susceptible individuals. Symptoms of a yeast allergy may include rash, difficulty breathing, and anaphylaxis, requiring the vaccine to be withheld and an alternative plan considered.

B. Nuts. Nut allergies are not related to the hepatitis B vaccine, as it does not contain nut-derived ingredients. While nut allergies can be severe and cause anaphylaxis, they do not pose a specific risk in the administration of this vaccine. Therefore, the presence of a nut allergy alone does not require withholding the immunization.

C. Wheat. A wheat allergy is not a contraindication for the hepatitis B vaccine. Wheat allergies primarily cause reactions to gluten-containing foods or products but do not have any connection to the components used in the production of the vaccine. The vaccine can be safely administered to individuals with wheat allergies.

D. Egg yolk. While some vaccines, such as the influenza vaccine, may be derived from egg proteins, the hepatitis B vaccine is not produced using egg-based components. An allergy to egg yolk does not pose a risk for adverse reactions to this vaccine, so it should not be withheld in individuals with an egg allergy.