Renal impairment encompasses both acute and chronic renal failure, which may develop as a result of numerous disorders. The clinical presentation ranges from asymptomatic to life-threatening shock, depending on the severity of impairment. The diagnosis rests on the ability of the physician to recognize clinical features and conduct a thorough laboratory workup, while the determination of the glomerular filtration rate is the cornerstone in determining the degree of renal failure.
A myriad of disorders may cause the inability of the kidneys to perform their respective function, and the term renal impairment encompasses two major disorders - acute and chronic kidney failure:
Renal impairment, both in the form of acute and chronic renal failure, could be severely harmful and even life-threatening for the patient in the absence of an early diagnosis . For this reason, physicians must obtain a thorough patient history and determine the presence of underlying disorders that may induce renal impairment, whereas a complete physical examination assesses the signs and symptoms and determine the next steps in workup . In fact, the clinical examination can lead to a prompt diagnosis in some cases, examples being prostate hypertrophy and cervical cancer, where the physician might be able to palpate the masses during rectal and vaginal examinations, respectively . As soon as a presumptive diagnosis is made, a meticulous laboratory workup needs to be performed. A complete blood count (CBC), kidney function tests (urea and creatinine), urinalysis, serum glucose levels, complete coagulation panel, serum electrolytes (sodium, potassium, bicarbonate, calcium, and phosphate), inflammatory parameters (erythrocyte sedimentation rate, C-reactive protein), liver transaminases, and in most severe patients, arterial blood gasses must be included   . Imaging studies are equally important in determining the cause of kidney failure, with abdominal ultrasonography being the gold standard for evaluation of kidney anatomy and structure  . To assess the degree of kidney failure, determination of GFR using creatinine and specific calculations is vital in establishing the severity of renal impairment  .