Evaluating the clinical and cost-effectiveness of sodium bicarbonate administration for critically ill patients with acute kidney injury and metabolic acidosis
Critically ill patients with metabolic acidosis and acute kidney injury
For patients randomised to the intervention group, clinical staff will administer sodium bicarbonate 8.4% weight/volume intravenously, aiming to restore pH to >=7.30. The intervention will continue for the duration of the critical care unit admission or until initiation of kidney replacement therapy. For patients receiving sodium bicarbonate, the starting dose is 50ml administered over 30-60 minutes. Arterial blood gas analysis should be performed 1-2 hours after each infusion. Participants should be assessed for response to treatment and repeated doses should be administered depending on subsequent pH readings and clinical status (including haemodynamic monitoring heart rate, blood pressure), as well as blood gas analysis (including pCO2 HCO3 and electrolytes) up to a maximum of 500ml over a 24-hour period. Patients randomised to the control group will not receive IV sodium bicarbonate. Once eligible participants have been randomised, indications to commence KRT may subsequently develop and in these situations KRT may be initiated at the discretion of the treating clinician. In both groups, all other care will be provided by the discretion of the treating clinical team according to local routine practice.
Current inclusion criteria as of 19/12/2022: 1. Adult (aged ≥18 years) 2. Metabolic acidosis (defined by arterial blood gas values of pH <7.30 and PaCO2 <6.5 kPa) 3. AKI – categorised as stage 2 or 3 of the Kidney Disease Improving: Global Outcomes (KDIGO) classification, defined as any one of the following three criteria: • Serum creatinine ≥2.0 times baseline* or • Serum creatinine ≥354 μmol/L, AND either a rise of ≥27 μmol/L within 48 hours or serum creatinine ≥1.5 times baseline* or • Urine output of <0.5 ml/kg/h for ≥12 hours *For baseline serum creatinine value: • If available, then use pre-hospitalisation value within 365 days of the current hospital admission date. • If there are multiple pre-hospitalisation values, then use the one closest to the date of the current hospital admission. • If a pre-hospitalisation value from the 365 days prior to admission date is not available and there are multiple serum creatinine values from the current hospitalisation, then use the lowest one from the current hospitalisation. • If no baseline serum creatinine value is available, then estimate it using the provided calculator. _____ Previous inclusion criteria: 1. Adult (aged ≥18 years) 2. Metabolic acidosis (defined by arterial blood gas values of pH <7.25, PaCO2 <6.5 kPa and bicarbonate ≤20 mmol/L) 3. AKI – categorised as stage 2 or 3 of the Kidney Disease Improving: Global Outcomes (KDIGO) classification, defined as any one of the following three criteria: • Serum creatinine ≥2.0 times baseline* or • Serum creatinine ≥354 µmol/L, AND either a rise of ≥27 µmol/L within 48 hours or serum creatinine ≥1.5 times baseline* or • Urine output of <0.5 ml/kg/h for ≥12 hours *For baseline serum creatinine value: • If available, then use pre-hospitalisation value within 365 days of the current hospital admission date. • If there are multiple pre-hospitalisation values, then use the one closest to the date of the current hospital admission. • If a pre-hospitalisation
Current exclusion criteria as of 16/01/2025: 1. Respiratory acidosis (acute or chronic) 2. Kidney replacement therapy (KRT) planned to start within 3 hours and treating clinician(s) unwilling to defer if randomised to sodium bicarbonate 3. Deemed unsuitable for KRT 4. High output stoma/ileostomy 5. Percutaneous biliary drainage 6. End stage kidney failure defined as documented eGFR<15 ml/min/1.73m² prior to onset of this acute illness or end stage kidney disease (ESKD) on dialysis 7. Known renal tubular acidosis 8. Diabetic ketoacidosis 9. High anion gap acid poisoning (e.g. polyethylene glycol (PEG), aspirin, methanol) 10. Symptomatic hypocalcaemia (Ionised calcium <1.05 mmol/L) † 11. Hypernatraemia (Plasma sodium >150 mmol/L) † 12. Severe hypokalaemia (Potassium <3.0 mmol/L) † 13. Death perceived as imminent 14. Known hypersensitivity to sodium bicarbonate or to any of the excipients listed in section 6.1 of the SmPC 15. Previously randomised into MOSAICC † Exclusion criteria 10-12 are dynamic, and if corrected, patient may be reconsidered for the trial. _____ Previous exclusion criteria as of 19/12/2022: 1. Respiratory acidosis (acute or chronic) 2. Kidney replacement therapy (KRT) immediately indicated and treating clinician(s) unwilling to defer if randomised to sodium bicarbonate 3. Deemed unsuitable for KRT 4. High output stoma/ileostomy 5. Percutaneous biliary drainage 6. End stage kidney failure defined as documented eGFR<15 ml/min/1.73m² prior to onset of this acute illness or end stage kidney disease (ESKD) on dialysis 7. Known renal tubular acidosis 8. Diabetic ketoacidosis 9. High anion gap acid poisoning (e.g. polyethylene glycol (PEG), aspirin, methanol) 10. Symptomatic hypocalcaemia (Ionised calcium <1.05 mmol/L) † 11. Hypernatraemia (Plasma sodium >150 mmol/L) † 12. Severe hypokalaemia (Potassium <3.0 mmol/L) † 13. Death perceived as imminent 14. Known hypersensitivity to sodium bicarbonate or to any of the excipients listed in section 6.1 of