In whichever specialty you work, you will encounter large numbers of patients with chronic kidney disease and this will impact many components of their care. Your role as a junior is preventing further decline of renal function, by monitoring and managing AKI efficiently and being aware of how to avoid and treat or escalate any major complications. There are separate articles if your patient has AKI or is on dialysis.

CKD is often picked up in hospital on routine blood tests as patients are often asymptomatic. Figures suggest approximately 10% of all patients and up to 50% of patients >75 years have CKD.

Usually, these patients are managed by their GP with monitoring of their renal function, proteinuria and complications. Complex, rapidly deteriorating or severe CKD (stage 4 or 5) is often managed by the renal team for specialised investigations or for consideration of renal replacement therapy (dialysis or transplant). In this article, we won’t deal with the causes or investigations as this is quite specialist.

History

• The usual full clerking plus…
• Focus on co-morbidities and family history that might explain the underlying aetiology: hypertension, diabetes mellitus or vascular risk factors & autoimmune diseases
• Ask about complications
  • Uraemia (often >40, but quite variable): lethargy, itch, nausea, anorexia, confusion, pericarditis
  • Anaemia (is it symptomatic?)
  • Fluid retention (peripheral oedema, pulmonary oedema). Patients may not immediately volunteer this information, so ask if they’ve gained weight they weren’t expecting recently, if their legs feel heavier than usual or if they’ve gotten new shortness of breath (especially orthopnea).
• Drug history: antihypertensive, phosphate binders, erythropoietin

For those known to have CKD

• How has this been investigated and are they under the renal team?
  • Previous biopsies?
  • Patients often have good knowledge about precautions you might need to take with them
  • If they are under the renal team, review their last letter
• What long term renal replacement therapy options have been offered?
  • If they are on the transplant list be cautious about forming antibodies with blood transfusions
  • If they have ever had a transplant, have a low threshold to involve their transplant team
• Are they on dialysis?
  • Haemodialysis or peritoneal?
  • What do they use for access (e.g. fistula or line)?
  • How frequently do they dialyse & when did they last have dialysis?
  • Any complications
  • Do they usually pass urine? Are they fluid restricted and if so what is their dry weight?

Investigations

• Review their haemoglobin & electrolytes (including calcium & phosphate – hyperparathyroidism)
• Ensure you compare their baseline creatinine to what it is now
• HbA1c if diabetic
• VBG for bicarbonate & pH
• Coagulation
• Consider a renal USS if they have not had one before
• If you are requesting a contrast scan for a patient, make sure you flag this up with your seniors and radiologists, as in some rare cases, contrast can further damage the kidneys or even cause nephrogenic systemic fibrosis. While the risk is low, it is best to clear it with a senior.

Examination

• Review any signs of complications – anaemia, oedema (pulmonary, peripheral, ascites). Obtaining a weight is very important
• Review the access sites for infection concerns
• If there is a transplant, look for any tenderness

Management

Unfortunately, the more fragile the kidney the higher chance that acute illness will affect it significantly. An admission regularly causes acute deterioration.

• For AKI on CKD see our separate article
• Often hospitals have a renal bundle for patients being admitted with CKD
• If known to the renal team, ensure you advise them of the admission
• Monitor and manage hyperglycaemia & hypertension (aim for their normal BP to avoid sudden relative hypotension for them)
• Further management is based on complications
  • Electrolyte review (e.g. hyperkalaemia)
  • Fluid balance monitoring with a catheter if needed
  • Anaemia (blood transfusion or iron replacement)

Prescribing considerations

• The renal drug handbook is absolutely outstanding but the BNF and your pharmacist will be of great help too.
• Review medications carefully – paying careful attention to any medications that might need to be stopped (e.g. metformin) or have their dose adjusted.
  • Anticoagulants – often DOACs are avoided as DOAC clearance is reduced in severe renal failure. Most renal patients are at HIGHER risk of thrombotic events, so will require some form of antithrombotic agent. VTE prophylaxis may need adjusting too with unfractionated heparin considered for severe renal failure.
  • Antibiotics – particularly vancomycin or aminoglycosides like gentamicin
  • Opiates can accumulate causing toxicity, consider oxycodone & the lowest dose possible. Seek help from the pain team
  • Medications with a narrow therapeutic index e.g. digoxin or lithium
  • Antiepileptic drugs
• Avoid medications that might cause further decline e.g. NSAIDs. ACEI are often protective in the long term, but acutely they could be harmful
• Ensure you don’t miss their anti-rejection medications (which may need their levels monitored). In the context of infection, discuss with your seniors & the transplant team.

Further management considerations in CKD

• Cardiovascular disease is the most common cause of morbidity & mortality, therefore, ensure the modifiable risk factors (e.g. smoking, exercise, management of HTN and lipids) are well optimised & chest pain is considered seriously
• Hypertensive control can slow down the progression of CKD
  • CKD only: BP aims are 120-139/<90
  • CKD with proteinuria/diabetes: 120-129/<80
  • ACEI can delay end stage renal failure particularly in those with proteinuria or diabetes
• Glycaemic control
• Treatment of anaemia with the replacement of haematinics & consideration of erythropoietin improves the quality of life, slows progression and reduces cardiovascular outcomes. The aim is to maintain Hb between 100-120 g/L (higher “normal” values worsens outcomes)
• Mineral bone disorder
  • Calcium & phosphate homeostasis can be impaired. Normalising these values can delay the progression to hyperparathyroidism and delay vascular calcification
  • Treat hyperphosphataemia with dietary phosphate restriction and phosphate binders. Treat hyperparathyroidism with Vitamin D analogues. Maintain calcium within the normal range. Consider parathyroidectomy or calcimimetic drugs if indicated.

Surgical Management

As surgery can cause significant AKI, a thorough pre & post operative assessment is of great value. Focus on ensuring they have sufficient IV fluids (if NBM) & diabetes control. If known to the renal team, inform them & consider whether the patient needs HDU monitoring post-operatively for RRT timed around their surgery.

Renal team referral

If known to the renal team, have a low threshold for involving them. Other indications for renal team referral include:

• Rapidly deteriorating renal function (over days) or if the eGFR is newly below 30
• Proteinuria or haematuria for consideration of intrinsic renal disease e.g. glomerular or tubular
• Uncontrolled hypertension e.g. not being controlled with 4 agents
• For consideration of long term RRT which is usually planned well in advance with counselling & various investigations
• Acute RRT may be necessary for:
  • A: Acidosis that is refractory to bicarbonate
  • E: Electrolytes (hyperkalemia) refractory to diet & drug modifications or causing
  • I: Intoxication from drugs e.g. salicylates, lithium
  • O: Oedema refractory to furosemide causing respiratory distress
  • U: Uraemia as discussed earlier (encephalopathy or pericarditis)
  • If single organ (i.e. kidney) it might be the dialysis team that does this over ITU

Further Reading and References

• eLFH Module on CKD
• CKD Leaflet for Patients
• Kidney.org.uk – Support for patients
• Perioperative management in patients with CKD
• Anaesthesia in CKD
• Pathophysiology of CKD

Written by Dr Beccy Binks (Anaesthetics ST5)

Edits by Dr Akash Doshi CT2