Diseases and Surgical Procedures

Renal Failure Patients

Etiology of renal failure is important plus associated medical conditions

Effect on drug handling

  • Protein bound drugs have increased free fractions due to acidosis and hypoalbuminemia in the renal failure patient
  • Lipid insoluble drugs are excreted by renal
  • Kidney excretes hepatic metabolites of lipid soluble drugs
  • Uremia may change structure and function of drugs

Fluids and electrolytes

  • Hypervolemia
  • Edema
  • Hypertension
  • Metabolic acidosis
  • Hyperkalemia (may rise with Sux, catabolic stress, acidosis, K-sparing diuretics)
  • Hypermagnesia (inadequate dialysis)
  • Hypocalcemia : second to hyperparathyroidism and leading to bone resorption, osteoporosis, osteomalacia and fractures

Medical conditions with uremia 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 risk of acquired infection
  • Uremic coagulopathy

Assessment
  • Physical status and timing of last dialysis is important to know
  • Vascular access sites should be noted with reference to any shunts, avoid BP measurements in shunt arm
  • Optimal time 24 hour post hemodialysis but peritoneal can be carried on until surgery
  • Transfusion during dialysis preferably
  • Urea and Electrolytes Test: correct hypertension and hyperkalemia prior to 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 metabolite 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