Diagnostic Tests And Contrast Allergy Precautions - NCLEX Rn
- What instruction should be given after iodinated contrast if no fluid restriction exists?
- Increase oral fluids to help excrete contrast. Enhanced hydration promotes renal clearance, reducing retention and potential toxicity.
- Which medication should be held around iodinated contrast administration due to lactic acidosis risk if AKI occurs?
- Metformin. Contrast-induced AKI can cause metformin accumulation, increasing lactic acidosis risk in diabetic patients.
- What is the immediate nursing action for suspected contrast extravasation at an IV site?
- Stop injection, elevate limb, and notify radiology/provider. Immediate cessation and elevation reduce tissue exposure to hyperosmolar contrast, minimizing necrosis risk.
- Which complication is a priority to monitor for after a barium enema, especially in older adults?
- Constipation or fecal impaction. Retained barium can harden, leading to obstruction, particularly in those with reduced motility.
- Identify the best nursing response when a patient says, "I cannot have contrast because I am allergic to shellfish."
- Shellfish allergy alone does not predict contrast reaction; assess prior contrast reaction. This educates on the iodine myth and refocuses on true predictors like prior contrast exposure.
- Which action should the nurse take first when a patient with prior contrast anaphylaxis arrives for a contrast CT without premedication orders?
- Hold the study and notify provider/radiology for an alternative or premedication plan. History of anaphylaxis necessitates premedication or non-contrast options to avoid life-threatening recurrence.
- What is the priority assessment immediately after IV contrast administration during CT?
- Airway and breathing for early hypersensitivity reaction. Contrast can trigger rapid anaphylactoid reactions, necessitating vigilant monitoring for airway compromise.
- Which patient condition increases risk for contrast-associated kidney injury and requires extra precautions?
- Chronic kidney disease (reduced eGFR). Reduced clearance prolongs contrast exposure, heightening nephrotoxic effects on tubules and vasculature.
- Which symptom indicates a severe contrast reaction requiring emergency response?
- Stridor with respiratory distress. Stridor signals laryngeal edema or bronchospasm, escalating to potential airway obstruction in anaphylaxis.
- Which pre-procedure action is essential before any contrast study to prevent wrong-patient or wrong-allergy errors?
- Verify patient identity and documented allergies. Accurate verification upholds safety protocols, preventing administration errors and allergic complications.
- Which imaging study commonly uses barium sulfate as oral or rectal contrast?
- Upper GI series or barium enema (lower GI series). Barium's high atomic number provides radiopacity for detailed GI tract visualization under fluoroscopy.
- Which patient is at highest risk for nephrogenic systemic fibrosis with gadolinium contrast?
- Patient with severe renal failure (very low eGFR). Impaired excretion in renal failure allows gadolinium deposition, triggering fibrotic skin and organ changes.
- What is the key nursing action when a patient reports a prior contrast reaction before a CT with contrast?
- Notify provider and radiology; do not administer until evaluated. This allows for risk assessment, potential premedication with steroids/antihistamines, or alternative imaging to ensure safety.
- What is the key post-procedure nursing instruction after a barium study?
- Increase fluids and fiber; expect light/white stools. This promotes barium excretion to prevent constipation and informs about temporary stool discoloration from residual contrast.
- Which patient history finding is the strongest predictor of iodinated contrast reaction risk?
- Prior allergic-like reaction to iodinated contrast. A prior reaction indicates sensitization, making recurrence up to 60% more likely without premedication.
- What is the priority screening question before MRI to prevent device-related injury?
- Presence of implanted ferromagnetic metal or pacemaker/ICD. Strong magnetic fields can torque metals or interfere with device function, risking burns or malfunctions.
- Which symptom is most consistent with a mild iodinated contrast reaction?
- Limited urticaria or pruritus. Mild reactions often involve histamine-mediated skin symptoms without systemic involvement.
- Which order should the nurse question for a CT with iodinated contrast in a patient with eGFR mL/min/1.73 m?
- Proceeding with iodinated contrast without renal-risk mitigation plan. Severely reduced eGFR heightens AKI risk, requiring hydration, low-osmolar contrast, or alternatives.
- Which contrast agent is typically used for MRI enhancement instead of iodinated contrast?
- Gadolinium-based contrast. Gadolinium shortens T1 relaxation times, enhancing signal intensity in vascular and pathological tissues on MRI.
- Identify the correct action when a patient reports wheezing and facial swelling during contrast injection.
- Stop contrast, call rapid response, maintain airway, give O2. These signs indicate anaphylaxis, demanding prompt intervention to prevent respiratory failure.
- Which allergy history does NOT reliably predict iodinated contrast allergy and should not be treated as equivalent?
- Shellfish allergy. Shellfish reactions stem from proteins like tropomyosin, not iodine, lacking correlation with contrast hypersensitivity.
- Which baseline lab is most important to review before iodinated contrast in a patient with kidney disease?
- Serum creatinine or estimated glomerular filtration rate (eGFR). These metrics evaluate renal function to stratify risk for contrast-induced nephropathy before administration.
- What is the priority nursing intervention to reduce kidney injury risk with iodinated contrast when ordered?
- Ensure adequate hydration as prescribed. Pre- and post-procedure hydration dilutes contrast and enhances renal perfusion, mitigating nephrotoxicity.
- Which instruction is most appropriate for a patient who had a barium swallow this morning and has not had a bowel movement?
- Increase fluids and fiber; use laxative if prescribed. These measures facilitate barium passage through the GI tract, averting impaction from delayed elimination.
- What is the main renal risk associated with iodinated IV contrast in CT imaging?
- Contrast-associated acute kidney injury. Iodinated agents can induce tubular toxicity and vasoconstriction, impairing renal function in at-risk patients.