CHAPTER 22 Renal Disorders 557
home setting), peritoneal dialysis, or renal transplant. In contrast to hemodialysis, peritoneal dialysis is much less efficient in terms of solute clearance. Greater than 85% of CKD patients utilize hemodialysis in a clini- cal setting. Commonly accepted criteria for initiating patients on dialysis include: • The presence of uremic symptoms • The presence of hyperkalemia unresponsive to conservative measures • Persistent hypervolemia despite diuretic treat- ment • Acidosis refractory to medical therapy • Tendency to spontaneously bleed or bruise • Creatinine clearance or estimated GFR less than 10 mL/min per 1.73 m 2 Once the GFR is lower than 10 mL/min (normal 90 to 120 mL/min), dialysis is initiated, and the patient will be evaluated for a kidney transplant. Kidney trans- plantation offers the best potential for complete reha- bilitation because dialysis replaces only a fraction of the kidney’s filtration function and none of the other vital functions of the kidney.
Encephalopathy: poor concentration, lethargy, stupor, coma
Thrombocytopenia due to lysis of platelets. Symptoms are epistaxis (nosebleeds), spontaneous bruising, gum bleeding.
Uremic frost and fetor: perspiration and saliva are high in urea. Hyperparathyroidism
Hypertension due to high renin secretion Heart failure due to HTN and hypervolemia
Anemia due to lack of erythropoietin. Symptoms include weakness, dizziness, pallor. Electrolyte imbalances Hyperkalemia Metabolic acidosis High blood urea nitrogen (BUN) High serum creatinine
Infertility, erectile dysfunction
Renal osteodystrophy: osteoporosis due to lack of vitamin D
Edema: due to lack of filtration of kidney; water accumulates
Peripheral neuropathy
FIGURE 22-14. Widespread complications of ESRD.
Chapter Summary • Between 1990 and 2015, the prevalence of ESRD has increased almost 100% within the population. Aging of the population and increased prevalence of DM and HTN are reasons for increased kidney disease in the United States. • As of 2021, one in seven adults in the United States have chronic kidney disease (CKD). Also, as many as 9 in 10 adults with CKD do not know they have this disorder. • African Americans have the greatest incidence of kidney disease. • The renal blood filtered per unit of time is known as the GFR. Normal GFR is 90 to 120 mL/min. • To calculate accurate GFR, clinicians need to use a specific formula that involves age and sex of the patient and serum creatinine. • The GFR decreases as a physiological change of aging. Because older adults take the greatest number of prescription drugs, decreased GFR raises risk of medication toxicity. • AKI is divided into three categories based upon the mechanism of injury: prerenal azotemia, intrinsic renal disease, and postrenal obstruction.
• Prerenal azotemia is caused by lack of circulation to the kidney due to hypovolemia, excessive blood loss, or severe dehydration. • Intrinsic renal disease is commonly due to nephrotoxic drugs, infection, autoimmune disease of the kidney, or trauma of the kidney. • Postrenal obstruction is caused by obstruction of urinary outflow, which is commonly caused by nephrolithiasis, prostate enlargement (BPH or cancer), neurogenic bladder, or bladder tumor. • Postrenal obstruction can lead to hydronephrosis, swelling of the renal pelvis, and compression of nephrons. • ADPKD is the most common hereditary cause of renal disease in adults. • ATN occurs when there is ischemia of the kidney. It is the most common cause of AKI. • Azotemia is the increased amount of urea in the bloodstream. • Serum creatinine is the best parameter used to indicate kidney function.
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