A 4-year-old child with hemolytic-uremic syndrome (HUS) is admitted to the pediatric intensive care unit. The child has oliguria, elevated blood pressure, and laboratory results showing hemoglobin 6.8 g/dL, platelet count 45,000/mm³, and elevated BUN and creatinine. What is the priority nursing intervention?
1Monitor strict intake and output and maintain fluid restriction as ordered✓ 정답
2Administer packed red blood cells immediately to correct anemia
3Encourage increased oral fluid intake to prevent dehydration
4Prepare the child for immediate platelet transfusion
해설
In HUS with oliguria and acute kidney injury, strict fluid management is critical to prevent fluid overload and complications like pulmonary edema. Other options (immediate transfusions or increased fluids) are not priority as they can worsen the condition.
This question tests your ability to prioritize nursing interventions for a child with hemolytic-uremic syndrome (HUS), specifically the Shiga toxin-producing Escherichia coli (STEC-HUS) variant. The core pathophysiology involves a triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury (AKI) [1]. Understanding the mechanism of renal injury is key to identifying the priority.
Deconstructing the Clinical Presentation
The child's data aligns perfectly with the classic HUS triad described in the literature [1]:
Oliguria and elevated BUN/creatinine: These directly indicate acute kidney injury (AKI). In STEC-HUS, Shiga toxin damages the glomerular endothelial cells, causing microthrombi to form in the renal microvasculature. This reduces the glomerular filtration rate (GFR), leading to fluid retention, electrolyte imbalances, and accumulation of nitrogenous waste products.
Elevated blood pressure: This is a direct consequence of fluid overload from the failing kidneys' inability to excrete sodium and water. It is a hallmark of AKI in this setting.
Hemoglobin 6.8 g/dL and platelet count 45,000/mm³: These reflect the non-immune microangiopathic hemolytic anemia and thrombocytopenia. Red blood cells are mechanically sheared as they pass through platelet-fibrin rich microthrombi in small vessels, leading to anemia and consumption of platelets.
Why Fluid Management is the Priority
The priority intervention is to monitor strict intake and output and maintain fluid restriction as ordered. The rationale is rooted in the pathophysiology of the primary life-threatening complication at this stage: AKI-induced fluid overload.
The Kidney as the Central Problem: STEC-HUS is identified as "the major infectious cause of AKI in children" [1]. The kidneys are the primary target organ. When they fail, the body cannot excrete fluid. Unrestricted fluid intake in an oliguric patient will rapidly worsen fluid overload, leading to severe hypertension, pulmonary edema, and heart failure. These are immediate, life-threatening complications that the nurse can directly prevent.
Why not blood products first? Administering packed red blood cells (option 2) or platelets (option 4) is generally avoided unless there is active, life-threatening hemorrhage or severe symptomatic anemia with hemodynamic instability. Transfusions can "add fuel to the fire" by providing more cells to be consumed in the microthrombotic process, potentially worsening the condition. Fluid overload from blood product volume is also a significant risk in an oliguric patient. Therefore, managing the AKI and its complications takes precedence.
Why not encourage oral fluids? Encouraging increased oral fluid intake (option 3) is contraindicated. The child is oliguric due to intrinsic kidney damage, not prerenal dehydration. Forcing fluids would directly exacerbate fluid overload, hypertension, and the risk of pulmonary edema.
The nursing priority is to manage the AKI by meticulously documenting fluid balance and adhering to restrictions, which directly mitigates the risks of hypertension and volume overload [1].
References (research sources)
[1]
Diagnosis and Treatment for Shiga Toxin-Producing Escherichia coli Associated Hemolytic Uremic Syndrome.Research articleLiu Y, Liu Y, Thaker H, Wang C, Xu Z, Dong M. (2022) · DOI: 10.3390/toxins15010010
Clinical Practice Guide: Fluid Management in Pediatric HUS with AKI
This guide outlines the priority nursing actions for a child with hemolytic-uremic syndrome (HUS) presenting with oliguric acute kidney injury (AKI), based on the clinical scenario of a 4-year-old with hypertension, anemia, and thrombocytopenia.
1. Assessment and Monitoring
Strict Intake and Output (I&O): Document all sources of intake (IV fluids, medications, oral intake if allowed) and output (urine, stool, emesis, drains) hourly. Use a urine collection bag or indwelling catheter for accurate measurement in oliguric patients.
Daily Weight: Obtain a precise weight at the same time each day, on the same scale, to monitor fluid balance trends. A rapid increase suggests fluid retention.
Vital Signs: Monitor blood pressure every 1-2 hours or more frequently if unstable. Hypertension is a direct consequence of fluid overload and can lead to hypertensive encephalopathy. Assess heart rate, respiratory rate, and oxygen saturation for signs of pulmonary edema.
Fluid Status Assessment: Assess for peripheral or periorbital edema, lung crackles, jugular venous distension, and hepatomegaly. Auscultate lungs for crackles indicating pulmonary congestion.
Laboratory Monitoring: Track BUN, creatinine, and electrolytes (especially potassium) closely. Rising levels indicate worsening AKI. Monitor hemoglobin and platelet counts, but do not base transfusion decisions on numbers alone.
2. Fluid Management Strategy
Fluid Restriction: Adhere strictly to the prescribed fluid restriction, which typically limits total daily intake to insensible water loss (approximately 400 mL/m²/day) plus urine output from the previous day. This is the cornerstone of management in the oliguric phase.
IV Fluid Selection: Use concentrated IV solutions when possible for medication administration to minimize volume. Avoid hypotonic fluids, which can worsen hyponatremia and cerebral edema.
Oral Intake: Oral fluids are usually restricted or prohibited. Provide meticulous oral care to manage thirst without adding fluid volume.
Diuretic Therapy: Diuretics like furosemide may be prescribed to promote urine output, but their effectiveness is limited in established acute tubular necrosis. Do not administer without a specific order and only after ensuring the patient is not hypovolemic.
3. Management of Anemia and Thrombocytopenia
Red Blood Cell Transfusion: Transfusion is not based on a hemoglobin threshold alone. It is indicated for symptomatic anemia (tachycardia, hypotension, altered mental status) or active bleeding. Administer slowly and cautiously to avoid volume overload, often with concurrent diuretic therapy.
Platelet Transfusion: This is generally avoided. Platelet infusion can fuel the formation of new microthrombi, worsening the underlying disease process. It is reserved exclusively for life-threatening hemorrhage or an invasive procedure with high bleeding risk.
Nursing Action: Minimize venipunctures and invasive procedures. Apply prolonged pressure to puncture sites. Avoid intramuscular injections. Monitor for signs of bleeding: petechiae, purpura, oozing from gums or IV sites, hematuria, and changes in neurological status.
4. Renal Replacement Therapy (RRT) Preparation
Indications for Dialysis: Prepare for peritoneal dialysis or continuous renal replacement therapy (CRRT) if the patient develops severe fluid overload unresponsive to fluid restriction and diuretics, severe hyperkalemia, metabolic acidosis, or symptomatic uremia (pericarditis, encephalopathy).
Family Education: Explain the purpose and procedure of dialysis in simple terms, emphasizing that it is often temporary and supports the kidneys while they heal.
Hemolytic-Uremic Syndrome (HUS) — A clinical syndrome characterized by the triad of microangiopathic hemolytic anemia, thrombocytopenia, and acute kidney injury, most commonly caused by Shiga toxin-producing E. coli.
Oliguria — Abnormally low urine output, often defined as less than 1 mL/kg/hr in children, indicating a significant reduction in kidney function.
Microangiopathic Hemolytic Anemia — A type of anemia caused by the mechanical destruction of red blood cells as they pass through small vessels narrowed by platelet-fibrin clots or damaged endothelium.
Acute Kidney Injury (AKI) — A sudden decrease in kidney function, leading to the retention of waste products (elevated BUN and creatinine), fluid and electrolyte imbalances, and reduced urine output.
Fluid Restriction — A medical order limiting the total volume of fluid a patient can receive, crucial in managing fluid overload states like the oliguric phase of AKI to prevent hypertension, edema, and heart failure.