Peri-operative management of the dialysis patient

1. Peri-operative management of the dialysis patient Pelonomi: Firm 4 Consultant: drFlooks Registrar: A vd Horst

2. Our patient • 49yr lady from Rocklands • Hypertensive nephropathy on chronic haemodialysis • Anterior abdominal wall mass ? Desmoid tumor • Excision biopsy

3. Special investigations Na 135 Cor Ca 3.10 K 3.2 Mg 0.76 Ur 3.0 P 0.63 Cr 214 Liverfunctions: albumin 22 tot protein 76 rest normal

4. Special investigations • FBC: wcc 8.4 x 109/ℓ Hb 8.0g/dℓ mcv 88.9fl pl 416 x 109/ℓ • Iron studies: serum iron 5.4ųmol/ℓ transferrin 0.7g/ℓ TF saturation 31%

5. Peri-operative management of the dialysis patient

6. Increased morbidity and mortality • High incidence of CAD and myocardial dysfunction • Difficulty in managing fluid and electrolytes - potassium • Inability to metabolize and excrete anaesthetic and analgesic agents • Bleeding complications • Poor BP control: both hypo – and hypertension

7. Issues of concern

8. Baseline lab evaluation • Anaemia • Nutritional status • Dialysis dose • Fluid and electrolyte management • BP control • Evaluation for cardiovascular disease • Correction of bleeding diathesis • Antibiotics • Glucose metabolism • IV access • Anaesthetic considerations

9. 1. Laboratory evaluation • Baseline investigations: - electrolytes, urea and creatinine - glucose - albumin - full blood count - coagulation profile - iron studies if anaemic - drug levels - digoxin

10. 2. Anaemia status • Elective surgery: Hb 12-13g/dℓ • Erythropoiesis stimulating agents (ESA) Important, because post – operatively: • transfusions are often needed due to blood loss intra-operatively • ESA – resistance

11. 3. Nutrition • Ability to heal post-surgery • Protein catabolic rate and albumin should be optimalized • Stop drugs decreasing appetite • Drugs to ameliorate gastroparesis • Nutritional supplements

12. 4. Intensive dialysis • Unknown whether delivery of intensive doses of dialysis prior to or during surgery improves outcome (Uptodate) • Discussion between the anaesthetist and the nephrologist

13. 5. Fluid and electrolyte management • Optimal volume status: estimation of the amount of fluid lost and administered during surgery • Normal saline vs Ringer’s lactate • Electrolytes – calcium and potassium

14. Hyperkalemia and emergency surgery • ECG – asses the physiological effect of hyperkalemia • Chronic renal failure patients – increased tolerance • ECG changes due to alteration in transcellular K⁺ gradient and not the absolute value • CRF – increased total body and intracellular K⁺ = normal ECG

15. Course of action is basedon the clinical setting If: • no ECG changes, • stable patient, • K⁺ 6 – 6.2 mmol/ℓ == cont surgery If : • ECG changes present = dialysis

16. If no dialysis facilities available: • Medical treatment - Calcium - Insulin and dextrose - Sodium bicarbonate - β-stimulants - Cation exchange resins - can be give PR if NPO - potential for post-op intestinal necrosis

17. 6. Blood pressure control Hypertension 1. Optimize volume status – optimal dry weight 2. Parenteralantihypertensives: labetolol, hydralazine ( with β – blocker) diltiazem, nitroglycerine, nitroprusside 3. Post-op – normal oral antihypertensive regimen, with close monitoring

18. Hypotension • Excessive fluid removal • Left ventricle dysfunction • Autonomic dysfunction • Pericardial tamponade • Vasodilatation from opioids / anxiolytics = Titration of anti-hypertensive treatment

19. 7. Cardiovascular evaluation • 50% of dialysis patients have CVS disease • American College of Cardiology / AHA • Risk stratification

20. 8. Bleeding tendency • Increased tendency to bleeding • Platelet dysfunction – uremia, anemia, hyperparathyroidism, aspirin • Bleeding time not recommended as screening test pre-op, except for renal biopsy and major vascular surgery • Raising hkt, desmopressin, cryprecipitate, dialysis, estrogen

21. 9. Peri-operative antibiotic use • In accordance with general surgical guidelines • Dose adjustments • Loading dose unchanged • Access procedures - fewer access infections

22. 10. Glucose metabolism • Better control @ home, than in hospital - change in physical activity - acute comorbid conditions - inability to ingest food - reality of surgery schedules

23. Type 1 DM – brittle - wide variations in glucose metabolism - serum ketones if DKA • Type 2 DM – induction of hyperglycemia - increased t½ of oral drugs

24. 11. IV access • Frequent IV lines may destroy future access sites • Avoid subclavian central lines = subclavian stenosis • CVP should not be placed on the same side as the AV access

25. 12. Anaesthetic considerations • Thiopental – doubled free fraction • Ketamine – hypertension • Propofol – hepatic metabolism - well tolerated

26. Succinylcholine – Hyperkalemia - K < 5mmol/ℓ - succinylmoncholine • NDMR: pancuronium and gallamine renally excreted = prolonged paralysis atracurium, vercuronium

27. Sedatives: benzo’s are protein bound = free fraction in CRF intermediate metabolites

28. Analgesia • Opioids – fentanyl drug of choice - avoid pethidine, propoxyphene - effects of morphine prolonged - half-life of metabolites prolonged • Paracetamol can be used without any dose adjustments

29. In short

30. In short Peri-operative management of the dialysis patient requires a focussed assessment of all 12 aspects, as well as careful liaison between the physician, surgeon and anaesthetist.

31. Back to our patient • She underwent surgery without any complications. • Histology: Lipoma

32. Thank you

33. Bibliography • Uptodate • Miller’s Anesthesia, 6th edition