A 65-year-old man comes to the emergency department due to fever, chills, and a productive cough for the past 3 days. He also has shortness of breath and right-sided chest pain that is worse with deep breathing. His other medical problems include coronary artery disease, type 2 diabetes mellitus, and hyperlipidemia. The patient's medications include low-dose aspirin, atorvastatin, metformin, and sitagliptin. He does not use tobacco, alcohol, or illicit drugs. His temperature is 39.2 C (102.5 F), blood pressure is 95/60 mm Hg, pulse is 112/min, and respirations are 24/min. Oxygen saturation is 96% on room air. Examination shows dry mucous membranes. Laboratory results are as follows: Chest x-ray reveals a right lower-lobe infiltrate. Blood cultures are obtained and intravenous fluids and antibiotics are administered. Which of the following is the most appropriate next step in management of this patient?

Question

A 65-year-old man comes to the emergency department due to fever, chills, and a productive cough for the past 3 days.  He also has shortness of breath and right-sided chest pain that is worse with deep breathing.  His other medical problems include coronary artery disease, type 2 diabetes mellitus, and hyperlipidemia.  The patient's medications include low-dose aspirin, atorvastatin, metformin, and sitagliptin.  He does not use tobacco, alcohol, or illicit drugs.  His temperature is 39.2 C (102.5 F), blood pressure is 95/60 mm Hg, pulse is 112/min, and respirations are 24/min.  Oxygen saturation is 96% on room air.  Examination shows dry mucous membranes.  Laboratory results are as follows:  Chest x-ray reveals a right lower-lobe infiltrate.  Blood cultures are obtained and intravenous fluids and antibiotics are administered.  Which of the following is the most appropriate next step in management of this patient?

Quizplus · Accepted Answer

This patient's clinical presentation - fever, cough, hypotension, tachycardia, and lung infiltrate on imaging - suggests sepsis due to community-acquired pneumonia. The patient also has dry mucous membranes and laboratory findings (high hemoglobin, blood urea nitrogen [BUN], and creatinine levels) suggestive of volume depletion. A BUN/creatinine ratio >20 is consistent with a prerenal cause of azotemia. Hypotension and volume depletion due to sepsis are typically treated with intravenous fluids (isotonic saline), which generally results in improvement of prerenal azotemia. However, this patient's clinical condition may temporarily worsen before improving if he develops acute tubular necrosis or septic shock. Therefore, any nephrotoxins (eg, nonsteroidal anti-inflammatory drugs) that can further worsen kidney function must be avoided. Metformin can cause lactic acidosis in acute kidney injury and sepsis and should be withheld until renal function improves. (Choice A) Low-dose aspirin use does not affect renal blood flow and has not been shown to precipitate or worsen renal failure in patients with otherwise normally functioning kidneys. Therefore, in this patient with coronary artery disease, it does not need to be stopped at this time. (Choice B) Statins are not known to cause acute kidney injury. Instead, myopathy is the most frequent side effect. There is no indication for stopping atorvastatin in this patient. (Choice D) Target blood glucose level for acutely ill patients with hyperglycemia is 140-180 mg/dL. Short-acting insulin regimens are typically recommended. This patient's blood sugar is currently controlled; intravenous insulin therapy is unnecessary and would put him at risk for hypoglycemia and adverse clinical outcomes. (Choice E) Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers can temporarily worsen renal function and hypotension, and should not be started in the setting of acute kidney injury. (Choice F) Hypercalcemia in this patient is most likely due to volume depletion and hemoconcentration. It should correct with hydration and does not require bisphosphonate therapy. Educational objective: Metformin should not be given to acutely ill patients with acute renal failure, liver failure, or sepsis as these conditions increase the risk of lactic acidosis. References: Inpatient treatment of type 2 diabetes. (http://www.ncbi.nlm.nih.gov/pubmed/22833757)

A 65-Year-Old Man Comes to the Emergency Department Due to Fever