A nurse is reviewing the most recent laboratory results of a client on the telemetry floor. The client is currently asymptomatic, and the telemetry monitor indicates sinus rhythm. Which of the following critical values is mostlikely due to laboratory error? A)Blood urea nitrogen (BUN) of 60 mg/dL (21.4 mmol/L) B)Creatinine of 4.0 mg/dL (354 µmol/L) C)Potassium of 7.0 mEq/L (7.0 mmol/L) D)Sodium of 155 mEq/L (155 mmol/L)

Question

Quizplus · Accepted Answer

With the exception of clients in end-stage renal disease, a serum potassium value >6.5 mEq/L (6.5 mmol/L) in any client who is walking and talking should raise the suspicion of an erroneously elevated serum potassium (pseudohyperkalemia) from poor hematology technique, hemolysis, or clotting. A serum potassium level of 7.0 mEq/L (7.0 mmol/L) would normally constitute a life-threatening electrolyte imbalance that would cause severe weakness or paralysis, unstable arrhythmias, and eventual cardiac arrest. An assessment would focus on evaluating cardiac symptoms and muscle strength and be reported to the health care provider (HCP). In this case, it is likely that a repeat blood draw would be prescribed. Pseudohyperkalemia can be avoided on the repeat blood draw by using heparin-impregnated hematology vials to prevent clotting, minimal use of a tourniquet and fist clenching, and use of a larger gauge needle for the sample. (Option A) This blood urea nitrogen (BUN) value is elevated (normal 6-20 mg/dL [2.1-7.1 mmol/L]) and could be related to kidney damage or dehydration. Therefore, it is not the most likely erroneous result. (Option B) Similar to the BUN level, this creatinine value is significantly elevated (normal 0.6-1.3 mg/dL [53-115 µmol/L]). Further nursing assessment is indicated, with documentation and involvement of the HCP in evaluating the impact of this kidney damage on the client's health. (Option D) This sodium value is high (normal 135-145 mEq/L [135-145 mmol/L]) and requires further exploration. The nursing assessment should be documented and reported to the HCP. Educational objective: High serum potassium levels could be due to hemolysis or clotting during the blood draw. If a clinical assessment does not correlate with the laboratory values, repeat testing is needed.

A Nurse Is Reviewing the Most Recent Laboratory Results of a Client