iThoughts

CRF can be associated with Na⁺ retention, depletion or normal Na⁺ balance and is influenced by diuretic use
Most have Na⁺ and water retention while extra cellular fluid remains isotonic.

Adaptive processes increase K⁺ secretion in the distal nephron and also in the gut
In acidosis, the serum K⁺ will rise 0.5mmol/L for every 0.1 unit decrease in pH

A common feature of ESRD. There is inability to excrete protons and buffers and there is little reserve to counter acute acidosis caused by sepsis

Plasma concentration of Ca²⁺ is reduced in CRF. Renal production of calcitrol (1,25-(OH)2D3) declines causing decreased intestinal absorption of calcium. Phosphate excretion is reduced and as concentrations increase, calcium phosphate is deposited in soft tissues, further lowering Ca²⁺. The low Ca²⁺ stimulates PTH leading to secondary hyperparathyroidism, which increases osteoclasts activity

Normochromic normocytic anaemia is common due to low epo and uraemia reduced red cell life. Chronic GI loss is also a problem. Compensatory increases in 2,3 DPG moves the curve to the right
Coagulopathy occurs despite normal PT, APTT and platelet numbers. It is multifactorial but rapid improvements in coagulation require the use of cryo, DDAVP (enhances VWf release)
Wait about 4-6hrs post dialysis for fluid compartment equilibration and heparin to clear
Pharmacokinetics

Hypoalbuminaemia and acidosis increase free drug availability of highly bound drugs.
Elimination of ionised or water soluble drugs is reduced
The loading dose duration of action depends more on redistribution
Lipid soluble drugs metabolised in the liver can have active water soluble metabolizes eg morphine, or significant S/E eg (nor-pethadine)
Metabolism of sevoflurane produces fluoride ions and their use in prolonged cases should be avoided
Excretion of anticholinergics and Anticholinesterases is prolonged
Duration of action of LA is reduced and doses should be reduced by 25% due to reduced protein binding and lower seizure threshold

Glucose tolerance is impaired but the insulin required is less due to reduced metabolism by the failing kidney.

Myoclonus, encephalopathy, seizures, personality changes and peripheral neuropathy can all occur. Dialysis dementia can occur after years of dialysis due to aluminium toxicity.

Anorexia, nausea and vomiting contributes to malnutrition. Delayed gastric emptying. PUD is common.

Sepsis is the leading cause of death due to inhibition of cell mediated immunity

HT occurs in 80% but less so in sodium wasting nephropathies such as PCKD. HT may need Rx with β-blockers, ACE(I), α-antagonists and vasodilators.
CVD is a common cause of mortality due to decreased triglyceride clearance, HT, fluid overload.
Decreases in surfactant leads to atelectasis