Nokea
A patients wound has begun to heal and the blood clot which formed is no longer necessary. When a blood clot is no longer needed, the fibrinogen and fibrin will be digested by which of the following?
- A. Plasminogen
- B. Thrombin
- C. Prothrombin
- D. Plasmin
Correct Answer: D
Rationale: The substance plasminogen is required to lyse (break down) the fibrin. Plasminogen, which is present in all body fluids, circulates with fibrinogen and is therefore incorporated into the fibrin clot as it forms. When the clot is no longer needed (e.g., after an injured blood vessel has healed), the plasminogen is activated to form plasmin. Plasmin digests the fibrinogen and fibrin. Prothrombin is converted to thrombin, which in turn catalyzes the conversion of fibrinogen to fibrin so a clot can form.
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A patient is receiving a blood transfusion and complains of a new onset of slight dyspnea. The nurses rapid assessment reveals bilateral lung crackles and elevated BP. What is the nurses most appropriate action?
- A. Slow the infusion rate and monitor the patient closely.
- B. Discontinue the transfusion and begin resuscitation.
- C. Pause the transfusion and administer a 250 mL bolus of normal saline.
- D. Discontinue the transfusion and administer a beta-blocker, as ordered.
Correct Answer: A
Rationale: The patient is showing early signs of hypervolemia; the nurse should slow the infusion rate and assess the patient closely for any signs of exacerbation. At this stage, discontinuing the transfusion is not necessary. A bolus would worsen the patients fluid overload.
The nurses brief review of a patients electronic health record indicates that the patient regularly undergoes therapeutic phlebotomy. Which of the following rationales for this procedure is most plausible?
- A. The patient may chronically produce excess red blood cells.
- B. The patient may frequently experience a low relative plasma volume.
- C. The patient may have impaired stem cell function.
- D. The patient may previously have undergone bone marrow biopsy.
Correct Answer: A
Rationale: Persistently elevated hematocrit is an indication for therapeutic phlebotomy. It is not used to address excess or deficient plasma volume and is not related to stem cell function. Bone marrow biopsy is not an indication for therapeutic phlebotomy.
The nurse is providing care for an older adult who has a hematologic disorder. What age-related change in hematologic function should the nurse integrate into care planning?
- A. Bone marrow in older adults produces a smaller proportion of healthy, functional blood cells.
- B. Older adults are less able to increase blood cell production when demand suddenly increases.
- C. Stem cells in older adults eventually lose their ability to differentiate.
- D. The ratio of plasma to erythrocytes and lymphocytes increases with age.
Correct Answer: B
Rationale: Due to a variety of factors, when an older person needs more blood cells, the bone marrow may not be able to increase production of these cells adequately. Stem cell activity continues throughout the lifespan, although at a somewhat decreased rate. The proportion of functional cells does not greatly decrease and the relative volume of plasma does not change significantly.
Through the process of hematopoiesis, stem cells differentiate into either myeloid or lymphoid stem cells. Into what do myeloid stem cells further differentiate?
- A. Leukocytes
- B. Natural killer cells
- C. Cytokines
- D. Platelets
- E. Erythrocytes
Correct Answer: A,D,E
Rationale: Myeloid stem cells differentiate into three broad cell types: erythrocytes, leukocytes, and platelets. Natural killer cells and cytokines do not originate as myeloid stem cells.
A patients diagnosis of atrial fibrillation has prompted the primary care provider to prescribe warfarin (Coumadin), an anticoagulant. When assessing the therapeutic response to this medication, what is the nurses most appropriate action?
- A. Assess for signs of myelosuppression.
- B. Review the patients platelet level.
- C. Assess the patients capillary refill time.
- D. Review the patients international normalized ratio (INR).
Correct Answer: D
Rationale: The INR and aPTT serve as useful screening tools for evaluating a patients clotting ability and to monitor the therapeutic effectiveness of anticoagulant medications. The patients platelet level is not normally used as a short-term indicator of anticoagulation effectiveness. Assessing the patient for signs of myelosuppression and capillary refill time does not address the effectiveness of anticoagulants.