Hyperkalaemia in CKD

Question 1

A 74 year old man has CKD stage 3 with eGFR 58. He is treated for hypertension with ramipril and amlodipine. In recent weeks he has been dizzy and his blood pressure is 98/56 mmHg. His serum potassium is 6.8 mmol/L. How would you manage him?

Imp/DDx/Goals

Answer 1

Impression:
Hyperkalaemia in setting of CKD and ACEi use. Hypotension likely secondary to medications use (antihypertensives), but would want to rule out shock. Main concern in hyperkalaemia is life-threatening cardiac arrhythmias.

DDx for hyperkalaemia

• cell turnover: haemolysis, tumour lyisis, rhabdo
• renal: AKI, CKD, metabolic acidosis
• medications: B Blockers, ACEi, Warfarin

Goals

• correct hyperkalaemia and prevent cardiac complications
• identify and treat underlying cause of hyperkalaemia with focussed H/E/I
• institute appropriate ongoing management strategies

Question 2

Hyperkalaemia in CKD - Assessment

Answer 2

Assessment
Given potential for life-threatening complications of hypokalaemia and significant hypotension, would take an A to E approach to assessment:
A - patent, maintaining. adjuncts as required
B - sats, RR, WOB, supplemental and escalate as required
C - 2xIVC, serial ECG, BP monitoring + supportive measures. Start hyperkalaemia treatment
- calcium gluconate (membrane stabilisation)
- HCO3-/insulin-dextrose/salbutamol (K+ intracellularly)
- diuretics/resonium/dialysis (K+ excretion)
- cease K+ increasing drugs (B Blockers, ACEi, etc)
- take bloods: FBC, UEC, VBG, CMP
D - GCS
E - secondary survey
F - NS

• escalate care by calling ICU/on-call registrar

Question 3

Hyperkalaemia in CKD - History

Answer 3

History

• sx: palpitations, muscle weakness, chest pain. fluid overload, SOB
• hypotension: postural, syncope?
• HxPC: time-course, progression
• PMHx: underlying medical conditions, existing treatments (dialysis?)
• medications
• SNAP

Question 4

Hyperkalaemia in CKD - Examination

Answer 4

Examination

• General observation + vital signs
• Cardiorespiratory examination: fluid overload, murmurs
• Fluid balance: MM, skin, weight, output vs input, etc

Question 5

Hyperkalaemia in CKD - Investigations

Answer 5

Investigations
-Key/diagnostic: ECG, VBG

• Bedside: VBG, serial ECG, urinalysis (CKD)
• Bloods: FBC, UEC, CMP, trops,
• Imaging: nil at present

Question 6

Hyperkalaemia in CKD - Management

Answer 6

Management
Supportive:
- volume resus as required
- electrolyte replacement
- fluid + salt restriction

Definitive:

• renal consult
• dialysis
• medications review
• BP maintenance: