The acceptable range for hemoglobin values on a control sample is 13 ± 0.4 g/dL. A hemoglobin determination is performed five times in succession on the same control sample. The results are (in g/dL: 12, 12.3, 12, 12.2, and 12.1). These results are:

Correct Answer: A

Rationale: Rationale for Choice A: The results are precise but not accurate. Precision refers to the consistency of results, which is evident as the values are close to each other (12, 12.3, 12, 12.2, and 12.1). However, accuracy refers to how close the results are to the true value. Since the average of the results is outside the acceptable range (12.12 g/dL vs. 13 g/dL), they are not accurate. Therefore, the correct choice is A. Summary of other choices: B: Both accurate and precise - Inaccurate as the average value is outside the acceptable range. C: Accurate, but not precise - Inaccurate as the results are not consistent. D: Neither accurate nor precise - Results are precise (consistent) but not accurate.

Correct Answer: B

Rationale: The correct answer is B: Check BP and pulse after ambulation. This task is appropriate to delegate to a nursing assistant as it involves monitoring vital signs post-activity, which is within their scope of practice. Nursing assistants are trained to perform basic assessments and report findings to the nurse. Choices A, C, and D involve assessing and making decisions about the patient's care, which should be done by a licensed nurse based on the patient's condition and individualized care plan. Checking BP and pulse after ambulation directly relates to the patient's activity intolerance and allows for immediate assessment of their response to activity, making it the most appropriate task to delegate in this scenario.

Correct Answer: A

Rationale: The correct answer is A: Alpha and beta. Hemoglobin A in normal adults consists of two alpha and two beta globin polypeptide chains. This is the most common form of hemoglobin in adults. The other choices (B: Alpha and epsilon, C: Alpha and delta, D: Alpha and brotherton) are incorrect because epsilon, delta, and brotherton are not the typical polypeptide chains found in adult hemoglobin. Hemoglobin F contains gamma and alpha chains, not epsilon or delta. Brotherton is not a known polypeptide chain in hemoglobin.

Correct Answer: B

Rationale: The correct sequence for testing a patient for antibody against the AIDS virus with the ELISA procedure is B. Step 1: HIV antigen is immobilized on a solid surface. Step 2: Patient's serum containing antibodies is added. Step 3: Enzyme-labeled antibody against human gamma globulin is added to detect patient antibodies. Step 4: Enzyme substrate is added to produce a measurable signal. This sequence allows for the detection of patient antibodies against the HIV antigen. Choices A, C, and D are incorrect because they do not follow the correct order of steps for an ELISA test. In these options, the order of the components is not suitable for detecting antibodies in the patient's serum effectively.

Correct Answer: B

Rationale: The correct answer is B: Obtain a therapeutic drug level. The rationale for this is that digoxin has a narrow therapeutic range, and monitoring drug levels is crucial to prevent toxicity or subtherapeutic effects. By obtaining a drug level, the nurse can ensure that the infant is receiving the appropriate dose. A: Calling for a portable chest radiograph is not necessary for assessing the infant's heart rate in this scenario. C: Reassessing the heart rate in 30 minutes does not address the need to confirm the drug level for proper dosing. D: Administering digoxin immune Fab (Digibind) stat is a drastic measure for digoxin toxicity, which is not indicated based solely on the heart rate assessment at this time.

Correct Answer: A

Rationale: The correct answer is A because swelling and redness at the biopsy site can indicate infection, which is a serious concern post-procedure. Red streaks (B) also suggest infection, but swelling and redness are more immediate signs. A low-grade fever (C) is common after a biopsy and may not necessarily indicate a problem. Pain (D) is expected after a biopsy and doesn't necessarily signify a complication. Therefore, choice A is the most concerning symptom that requires prompt attention.

Correct Answer: A

Rationale: The correct answer is A: Cryofibrinogen. Cryofibrinogenemia can cause a spurious decrease in Mean Corpuscular Volume (MCV) due to the presence of cryoprecipitates in the blood sample, leading to underestimation of red blood cell volume. Cryofibrinogen does not actually alter the size of the red blood cells, but its presence interferes with the accurate measurement of MCV. Summary: B: Hyperglycemia does not affect MCV. C: Autoagglutination causes clumping of red blood cells, leading to falsely elevated MCV. D: High white blood cell count does not directly impact MCV.

Correct Answer: B

Rationale: The correct answer is B: Within the first 20 minutes of administration of the transfusion. During the initial stage of transfusion, reactions are most likely to occur due to rapid infusion of blood. This is when the nurse should closely monitor the child for signs of transfusion reactions such as fever, chills, rash, or shortness of breath. Reactions can be severe and life-threatening, so early detection is crucial. Choices A, C, and D are incorrect because reactions are most likely to occur at the beginning of the transfusion due to immediate immune responses, rather than hours later, at the end of the transfusion, or not at all.

Correct Answer: A

Rationale: Step-by-step rationale: 1. Plasma is the liquid portion of blood. 2. Phospholipid is a component of platelet membrane needed for coagulation. 3. Calcium is required for the activation of coagulation factors. Therefore, the correct answer is A. Summary: B: Thromboplastin is not an ingredient in PTT. C: Thromboplastin is not part of PTT. D: Thrombin is a product of the coagulation cascade, not an ingredient in PTT.