Nephrology Flashcards
In a 35-year-old woman with a fever (38 C), chills, flank pains, and right costovertebral angle tenderness, the following should be done: (H20 C130 P971)
A. Do urinalysis, urine gram stain, and urine culture and sensitivity
B. Order blood culture and sensitivity at two sites
C. Order kidney ultrasound
D. All of the above
The answer is A. In an otherwise healthy woman who is not pregnant, acute onset of back pain, nausea/vomiting, or fever, with or without cystitis symptoms warrants urinalysis and culture. Blood cultures are not necessary for uncomplicated pyelonephritis in this population.
All of the following are risk factors for postoperative acute kidney injury EXCEPT: (H20 C304 P2102)
A. Cardiac surgery with cardiopulmonary bypass
B. Diabetes mellitus
C. Female sex
D. Intraoperative hypotension
E. Significant operative blood loss
Ischemia-associated AKI is a serious complication in the postoperative period, especially after major operations involving significant blood loss and intraoperative hypotension. The procedures most commonly associated with AKI are cardiac surgery with cardiopulmonary bypass (particularly for combined valve and bypass procedures), vascular procedures with aortic cross clamping, and intraperitoneal procedures. Severe AKI requiring dialysis occurs in ~1% of cardiac and vascular surgery procedures. The risk of severe AKI has been less well studied for major intraperitoneal procedures but appears to be of comparable magnitude. Common risk factors for postoperative AKI include underlying CKD, older age, diabetes mellitus, congestive heart failure, and emergency procedures. The pathophysiology of AKI following cardiac surgery is multifactorial. Major AKI risk factors are common in the population undergoing cardiac surgery. The use of nephrotoxic agents, including iodinated contrast for cardiac imaging prior to surgery, may increase the risk of AKI. Cardiopulmonary bypass is a unique hemodynamic state characterized by nonpulsatile flow and exposure of the circulation to extracorporeal circuits. Longer duration of cardiopulmonary bypass is a risk factor for AKI. In addition to ischemic injury from sustained hypoperfusion, cardiopulmonary bypass may cause AKI through a number of mechanisms including extracorporeal circuit activation of leukocytes and inflammatory processes, hemolysis with resultant pigment nephropathy (see below), and aortic injury with resultant atheroemboli. AKI from atheroembolic disease, which can also occur following percutaneous catheterization of the aorta, or spontaneously, is due to cholesterol crystal embolization resulting in partial or total occlusion of multiple small arteries within the kidney. Over time, a foreign body reaction can result in intimal proliferation, giant cell formation, and further narrowing of the vascular lumen, accounting for the generally subacute (over a period of weeks rather than days) decline in renal function.
