Renal failure affects multiple organ systems and increases the risk of perioperative morbidity and mortality. There are multiple etiologies of renal failure (Table 88-1).
TABLE 88-1Common Causes of Renal Failure ||Download (.pdf) TABLE 88-1 Common Causes of Renal Failure
Hypertension is both a common complication and a cause of chronic renal disease (Table 88-2). In patients with limited urine production, volume overload can lead to significant hypertension and/or pulmonary edema, particularly without the aid of dialysis. Therefore, the first line of therapy is either hemodialysis or diuretic therapy. Chronic renal failure (CRF) and end-stage renal disease (ESRD) also have direct effects on the heart. With long-standing hypertension, left ventricular hypertrophy and dysfunction occur. Coronary artery disease develops in an accelerated manner as well. Uremic pericarditis can occur in patients who are treated with dialysis. If pericarditis develops, tamponade should be ruled out.
TABLE 88-2Complications of Chronic Renal Disease ||Download (.pdf) TABLE 88-2 Complications of Chronic Renal Disease
|Cardiovascular ||Hypertension, accelerated CAD, LVH dysfunction, cardiomyopathy, congestive heart failure, uremic pericarditis, hemodynamic instability due to neuropathy |
|Neurologic ||Uremic encephalopathy, uremic neuropathy |
|Hematologic ||Anemia, platelet dysfunction, uremic prothrombin consumption, thrombosis |
|Immune system ||Infection |
|Gastrointestinal ||Malnutrition, delayed gastric emptying |
|Fluid and electrolytes ||Hypervolemia, hyperkalemia, hypocalcaemia, metabolic acidosis |
|Endocrine ||Hyperparathyroidism, vitamin D deficiency |
|Musculoskeletal ||Renal osteodystrophy |
Finally, low-pressure pulmonary edema may occur in patients without volume overload. Physical examination, ECG, chest X-ray, and cardiac stress testing assist in evaluation.
Anemia commonly ensues with CRF secondary to decreased erythropoietin production. Iron replacement and human recombinant erythropoietin prescriptions attempt to normalize hematocrit levels. This regimen limits blood transfusions and consequently limits transfusion-related cardiovascular complications. Hemoglobin and hematocrit should be checked prior to surgery.
Platelet dysfunction associated with abnormal platelet factor III and increased prothrombin consumption lead to prolonged bleeding time in renal failure patients. Hemodialysis decreases these effects but not completely.
Neurologic changes with CRF worsen as the kidney disease progresses. Initially, mild symptoms such as irritability and cognitive impairment may occur, but progression to seizures, uremic encephalopathy, and coma occurs if left untreated. Peripheral neuropathy with paresthesias and weakness is another common manifestation of CRF. Dialysis may reverse or slow down some of these neurologic effects.
Renal failure patients tend to have malnutrition, nausea and vomiting related due uremia. The malnutrition causes decreased plasma albumin levels and reduced protein binding. Elevated levels of free (unbound) drugs increase the risk of toxic drug levels in CKD patients.
Delayed gastric-emptying is a ...