Renal Failure Patients
The etiology of renal failure is essential, plus associated medical conditions
Effect on drug handling
- Protein-bound drugs have increased free fractions due to acidosis and hypoalbuminemia in renal failure patient
- Lipid-insoluble drugs are excreted by renal
- The kidney excretes hepatic metabolites of lipid-soluble drugs
- Uremia may change the structure and function of drugs
Fluids and electrolytes
- Hypervolemia
- Edema
- Hypertension
- Metabolic acidosis
- Hyperkalemia (may rise with Sux, catabolic stress, acidosis, K-sparing diuretics)
- Hypermagnesemia (inadequate dialysis)
- Hypocalcemia: second to hyperparathyroidism and leading to bone resorption, osteoporosis, osteomalacia, and fractures
Medical conditions with uremia are often seen with renal failure
- Hypertension
- Pericarditis and effusion
- Atherosclerosis and IHD
- Pulmonary edema
- Atelectasis, pneumonia and ARDS
- Depressed immunity
- Poor wound healing
- Peptic ulceration with elevated gastrin - increased risk of aspiration
Renal Failure Anemia
- Normochromic, normocytic, due to decreased erythropoietin secretion
- Multiple transfusions increase the risk of acquired infection
- Uremic coagulopathy
Assessment
- Physical status and timing of the last dialysis are essential to know
- Vascular access sites should be noted regarding any shunts, and avoid BP measurements in the shunt arm
- The optimal time is 24 hours post hemodialysis,s but peritoneal can be carried on until surgery
- Transfusion during dialysis, preferably
- Urea and Electrolytes Test: correct hypertension and hyperkalemia before surgery
- Clotting correction is important
Anesthetic Management
- Consider regional anesthesia if possible
- Avoid lactate-containing solutions; normal saline is preferred
- Patient positioning: consider shunt sites
- Watch fluid status/CVP monitoring, overloading is easy
- IV lines away from shunts
- Measure urinary output
- Rapid Sequence Induction (RSI) due to increased risk of aspiration
- Pre-oxygenation due to anemia
Drugs
- Succinylcholine may have a prolonged effect and may induce arrhythmias
- Avoid hypotension with induction agents; go slow
- Atracurium/vecuronium agents of choice, due to minimal renal excretion
- Avoid enflurane, as toxic metabolites are formed
- Treat hypotension with fluid
- Dopamine may increase renal perfusion
Postoperative
- Watch for fluid overload
- Dehydration
- Residual N-M blockade
- Watch basic metabolic panel blood test (BMP)
- Analgesia with regional or carefully titrated opioids