A 12-year-old child with von Willebrand's disease is schedul… | 마이메르시 MyMerci
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Child Health
문제

A 12-year-old child with von Willebrand's disease is scheduled for a dental extraction. Which nursing intervention is most appropriate to prepare this child for the procedure?

A 12-year-old child diagnosed with von Willebrand's disease requires a dental extraction due to severe tooth decay. The child has a history of prolonged bleeding after minor injuries and frequent nosebleeds. The parents are concerned about potential bleeding complications during the dental procedure.
해설
Children with von Willebrand's disease require special preparation before invasive procedures to prevent excessive bleeding. Desmopressin (DDAVP) is the treatment of choice for most patients with von Willebrand's disease as it increases the release of von Willebrand factor and factor VIII from endothelial cells, temporarily improving hemostasis.

Von Willebrand disease is the most common inherited bleeding disorder, affecting about 1% of the population. It is caused by a deficiency or dysfunction of von Willebrand factor (vWF), a protein essential for normal blood clotting.

Pathophysiologically, von Willebrand factor plays two important roles in the hemostatic process. First, it promotes platelet adhesion to damaged blood vessel walls, and second, it acts as a carrier protein for factor VIII. When vWF is deficient or its function is impaired, both primary hemostasis (platelet plug formation) and secondary hemostasis (the coagulation cascade) are compromised, leading to prolonged bleeding time.

Desmopressin (DDAVP) is the first-line treatment for type 1 von Willebrand disease and some type 2 patients. This drug works by stimulating the release of von Willebrand factor and factor VIII stored in Weibel-Palade bodies within vascular endothelial cells. This causes a temporary 2- to 5-fold increase in circulating clotting factor levels, which is usually sufficient to achieve hemostasis during minor surgical procedures.

The nursing intervention of coordinating DDAVP administration before dental extraction is crucial to prevent excessive bleeding. The drug is typically given 30–60 minutes before the procedure via intravenous, subcutaneous, or intranasal routes, depending on the formulation and patient factors. Nurses must monitor for potential side effects such as hyponatremia, headache, and facial flushing.

Option 1 (administering aspirin) is inappropriate because it inhibits platelet function and increases bleeding risk. Option 2 (fasting for 12 hours) is a general preoperative measure but is not directly related to bleeding prevention. Option 4 (applying an ice pack) has a local vasoconstrictive effect but does not address the underlying coagulation disorder.
같은 주제 다음 문제A nurse is assessing a 10-year-old child with suspected von Willebrand's disease. Which as…

심화 해설

Understanding the Pathophysiology
Von Willebrand disease (VWD) is the most common inherited bleeding disorder. In this condition, there is a quantitative deficiency or qualitative defect in von Willebrand factor (vWF), a crucial protein for hemostasis. Normally, when a blood vessel is injured, vWF acts like a molecular bridge, allowing platelets to adhere to the exposed subendothelial collagen at the injury site. It also serves as a carrier protein for factor VIII, protecting it from rapid degradation in the circulation. In a child with a history of prolonged bleeding and frequent nosebleeds, the vWF deficiency means primary hemostasis—the initial platelet plug formation—is impaired. A dental extraction creates a significant mucosal wound, posing a high risk for prolonged oozing because the formation of a stable initial clot is compromised [1].

Analyzing the Correct Intervention
The most appropriate nursing intervention is to coordinate with the physician to administer desmopressin (DDAVP) before the procedure. DDAVP is a synthetic analogue of the natural hormone arginine vasopressin. Its therapeutic effect in mild type 1 VWD is well-established: it acts selectively on V2 receptors, which stimulates the endothelial cells to release their stored vWF and factor VIII into the bloodstream [2]. This transiently raises the plasma levels of the deficient clotting factor, thereby temporarily correcting the hemostatic defect. For a planned surgical challenge like a dental extraction, administering DDAVP prophylactically increases vWF activity, significantly improving the child's ability to form a platelet plug and reducing the risk of procedural bleeding. This pharmacological strategy is a cornerstone of individualized surgical management for mild VWD, where the goal is to boost the patient's own factor stores rather than immediately relying on exogenous replacement therapy [1][3].

Critique of the Incorrect Options

Option 1: Administer aspirin 30 minutes before the procedure. This is contraindicated. Aspirin irreversibly inhibits platelet cyclooxygenase, which prevents the synthesis of thromboxane A2, a potent platelet aggregator. In a patient with an already compromised platelet adhesion mechanism due to vWF deficiency, administering an antiplatelet drug would further impair platelet function and dramatically increase the risk of severe, uncontrolled bleeding.



Option 2: Ensure the child fasts for 12 hours before the procedure. While a preoperative fasting order is common for procedures requiring general anesthesia or deep sedation, it is not a specific hemostatic intervention for VWD. The standard fasting guideline for clear liquids is typically 2 hours, and prolonged fasting in a child can lead to dehydration, hypoglycemia, and discomfort without providing any benefit for bleeding prevention. This action does not address the underlying coagulopathy.



Option 4: Apply ice packs to the jaw area immediately before the procedure. Applying cold causes local vasoconstriction, which can be a useful adjunct for superficial bleeding or post-procedural swelling. However, it is not a primary prophylactic measure for a systemic bleeding disorder. Vasoconstriction alone cannot compensate for the biological inability to form a platelet plug at the surgical wound site. This intervention fails to address the core pathophysiological defect of a missing clotting factor.


Clinical and Pharmacological Rationale
The decision to use DDAVP is based on a predictable pharmacodynamic response. By stimulating V2 receptors in the renal collecting ducts and vascular endothelium, DDAVP triggers the release of pre-synthesized vWF from Weibel-Palade bodies within endothelial cells [2]. This mechanism explains why it is effective primarily in type 1 VWD, where the vWF is functionally normal but quantitatively low. The released vWF immediately works to support platelet adhesion and stabilize factor VIII, directly counteracting the bleeding risk during the extraction. Decades of clinical evidence support the use of DDAVP as a first-line prophylactic agent for minor surgical procedures in responsive patients, allowing them to avoid the potential risks associated with plasma-derived factor concentrates [3]. The nurse's role is to verify the physician's order, ensure the medication is administered at the correct time pre-procedure (typically 30-60 minutes prior), and monitor the patient for therapeutic response and potential side effects such as mild tachycardia, facial flushing, or, rarely, hyponatremia due to its antidiuretic effect.

임상 시나리오

Preoperative DDAVP for VWDMinimizing bleeding risk during dental extraction

For a child with von Willebrand disease undergoing surgery, coordinate with the provider to administer desmopressin (DDAVP). DDAVP stimulates release of stored von Willebrand factor and factor VIII, transiently correcting the hemostatic defect.

A test dose should be given prior to the procedure to confirm response, typically aiming for a 2- to 4-fold increase in vWF levels. The dose is usually 0.3 mcg/kg IV or intranasally.

Caution

DDAVP is effective primarily in Type 1 VWD. It is ineffective in most Type 2 and Type 3 variants. Monitor for hyponatremia and fluid retention due to its antidiuretic effect, especially with repeat dosing.

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