Final answer:
An elevated serum creatinine of 1.8 mg/dL in an older adult female client who had a myocardial infarction should be recognized as indicating increased risk for acute kidney injury, considering the normal values for females and criteria for ARF diagnosis.
Step-by-step explanation:
A nurse monitoring an older adult female client who had a myocardial infarction (MI) for the development of acute kidney injury (AKI) should identify serum creatinine of 1.8 mg/dL as indicating an increased risk of AKI.
Important factors that help identify the risk of AKI include the increase in serum creatinine levels and the output of urine. For instance, a consensus criterion for the diagnosis of ARF (acute renal failure), which is a type of AKI, includes a serum creatinine increased 1.5 times or a urine production of <0.5 ml/kg body weight for 6 hours. Therefore, considering normal plasma creatinine values being 0.6-1.2 mg/dL for females, a level of serum creatinine 1.8 mg/dL is higher than normal and indicates a potential risk of developing AKI.
Furthermore, conditions such as dehydration, shock, or excessive use of diuretics could lead to pre-renal causes of AKI, resulting in decreased urine production and disturbances in body fluids and electrolyte levels.