Finishing Renal Disease Aging and death

Chronic Renal Failure Results from irreversible, progressive injury to the kidney. Characterized by increased plasma creatinine and urea, indicating decreased GFR, as well as loss of hormonal functions of the kidney.

Consequences of Kidney Failure: Problems with Na+ and Water Balance Na+ handling – can lead to hypo- or hypernatremia – If GFR is low, and salt intake is high, the kidney’s cannot excrete enough salt and salt is retained. – But, if the salt intake is very low, the diminished capacity of the tubule to reabsorb sodium can lead to excessive sodium loss and hyponatremia. Water handling: – The ability of the kidney to generate the osmolar gradient that allows for excretion of concentrated or dilute urine is compromised. – Problems of osmolarity (hypo or hypernatremia) occur if the patients drink too much or too little water. Consequences: – Hypertension – Edema

Other Consequences of Renal Failure Uric Acid retention – may result in gout or arthritis, also causes itchiness and rash. Potassium Handling – Potassium excretion increases with GFR. Big reductions in GFR result in inability to excrete K+, and increased plasma potassium results. – This can result in cardiac arrthymias. Acid Base Status – Normal metabolism results in the formation of acid, which is normally excreted in the urine. – When the GFR gets low enough, acids cannot be excreted and plasma pH drops (i.e. the concentration of H+ ions increases). Buildup of Drugs and Toxins – The kidney is a major site of excretion of many drugs. – Patients with reduced kidney function have a reduced ability to excrete these and they may build up in the blood.

Still Other Consequences of Renal Failure: Calcium metabolism – Failure to activate vitamin D decreases calcium absorption in the gut – Causes breakdown of bone – Also, failure to excrete phosphate leads to formation of calcium phosphate salts in soft tissues, which further lowers plasma calcium levels. Hormonal abnormalities – The kidneys help clear the body of insulin, so patient with renal failure often have hyperinsulinemia. – Sex steroid levels are low, often causing amenorrhea in women and impotence in men. Anemia – The kidney is the site of production of erythropoetin, a hormone necessary to the formation of red blood cells. Neurologic effects – Build up of toxins can cause seizures, and other neurologic problems Gastrointestinal consequences – Nausea and vomiting resulting from electrolyte disturbances.

Treatment of Chronic Renal Failure: Dialysis Hemodialysis – must go to a clinic about 3 times per week for about 4 hours Peritoneal Dialysis – more frequent, but can be done at home Also: Transplantation

Hemodialysis

Peritoneal Dialysis

Symptoms seen in 200 actively dying cancer patients Table Symptom Frequency (in percent) Noisy and moist breathing56 Urinary incontinence32 Urinary retention21 Pain42 Restlessness and agitation42 Dyspnea22 Nausea and vomiting14 Sweating14 Jerking, twitching, plucking12 Confusion8 From: Palliative Care Perspectives by James L. Hallenbeck, M.D Copyright © 2003 by Oxford University Press, Inc.