Chronic renal failure is a progressive and irreversible loss of renal function. (8!> The most common aetiologies of renal insufficiency ultimately leading to endstage renal disease are diabetes, hypertension, and glomerulonephritis. Less frequent causes (less than 5 per cent) include interstitial nephritis, obstruction, collagen vascular disease, and AIDS-related aetiologies. Loss of up to 75 per cent of glomerular filtration rate does not usually result in pronounced clinical symptoms, as the remaining glomeruli adapt with hyperfiltration. Serum creatinine is a sensitive indicator of early, subclinical, chronic renal failure. For example, the doubling of serum creatinine from 0.7 to 1.4 mg/dl signifies a loss of approximately 50 per cent of glomerular filtration rate, emphasizing the importance of early detection and prevention. Once renal insufficiency is established, there is a tendency for renal disease to progress regardless of the initial insult.
Patients with chronic renal failure usually become symptomatic when glomerular filtration rate is less than 10 ml/min. Uraemia affects every organ system, including the central nervous system. There may be arrhythmias, anorexia, nausea, vomiting, anion gap acidosis, hypocalcaemia, fluid overload, hyperlipidaemia, hyperparathyroidism, increased insulin resistance, pruritus, anaemia, bleeding disorders, pulmonary oedema, pneumonitis, pleuritis, gout, and muscle weakness. Neuropsychiatric manifestations of chronic renal failure include irritability, insomnia, lethargy, anorexia, seizures, and restless legs syndrome. (89 In contrast to acute renal failure—where neuropsychiatric signs and symptoms may appear with a creatinine level as low as 4 mg/dl—in chronic renal failure, patients may have a normal mental status examination with a serum creatinine level as high as 10 to 11 mg/dl. Symptomatic treatments with low-dose neuroleptics, antiseizure medications, or benzodiazepines are sometimes necessary in chronic renal failure.
The differential diagnosis of neuropsychiatric syndromes in patients with chronic renal failure includes hypercalcaemia, hypophosphataemia, hypoglycaemia, hyperglycaemia, hyponatraemia, hypernatraemia, drug intoxication, hypertensive encephalopathy, cerebrovascular disease, meningitis, encephalitis, and normal pressure hydrocephalus.'80» The pathophysiology of uraemic encephalopathy is unknown. Structural changes in the central nervous system have not been observed.
Kimmel et al.(8D studied the prevalence of hospitalizations for psychiatric illness in 176 368 patients with endstage renal disease and compared that rate with four other chronic medical conditions (diabetes, ischaemic heart disease, cerebrovascular disease, and peptic ulcer disease). Hospitalizations for mental disorders were 1.5 to 3.0 times higher in these patients than in patients with the four other chronic diseases. Dementias and depression were the most common reasons for hospitalization.
Sexual dysfunction is the rule for patients with endstage renal disease. Abrams et al.(83) found that 75 per cent of his sample of men with this disease reported a decrease in frequency of sexual intercourse of at least 50 per cent. Disruptions in sexual function, which may be physiological (e.g. vascular complications of diabetes, fatigue following dialysis treatments) or psychological or both, account for at least a portion of the dysphoria experienced by patients with endstage renal disease.'80»
The definitive treatments for most patients with chronic renal failure are transplantation or haemodialysis. In general, transplantation is encouraged because of a better quality of life and a greater chance for rehabilitation and symptom resolution. Researchers in three separate prospective studies found that patients who received renal transplants experienced better physical and psychological outcomes than patients who remained on dialysis. (8 85 and 86» Neuropsychiatric signs and symptoms resolve much more completely with transplantation than with haemodialysis. Psychiatric aspects of organ transplantation are discussed later. The psychiatric aspects of haemodialysis are discussed next.
Was this article helpful?