Management of Severe Metabolic Acidosis with Hypoxemia and Hypokalemia

Initial Evaluation and Prioritization

The American Thoracic Society recommends that patients with severe metabolic acidosis (pH <7.2) and hypoxemia (PaO2 52.3 mmHg, SatO2 78.9% with FiO2 55%) require immediate intubation and mechanical ventilation, as well as oxygen therapy with a reservoir mask at 15 L/min 2
The American College of Cardiology suggests that patients with severe metabolic acidosis (pH 7.13, base excess -10.3 mmol/L) and hypokalemia (K+ 3.3 mmol/L) should receive cautious correction of hypokalemia and consideration of sodium bicarbonate only if the pH remains <7.10 after optimizing ventilation 1

The American Thoracic Society recommends that patients with hypoxemic respiratory failure (SatO2 <85%) should receive oxygen therapy with a reservoir mask at 15 L/min, and that the goal of oxygen therapy should be to achieve a SatO2 of 94-98% (or 88-92% in patients with severe COPD) 2
The American Heart Association suggests that patients with severe metabolic acidosis and respiratory failure should receive mechanical ventilation to facilitate metabolic correction and prevent cardiovascular collapse 4

The American College of Surgeons recommends that patients with severe metabolic acidosis and signs of shock should receive a bolus of 20 mL/kg of 0.9% saline solution over 15-30 minutes, and that urine output should be monitored with a goal of >1 mL/kg/hour 1

The American College of Cardiology recommends that patients with severe metabolic acidosis and hypokalemia should receive cautious correction of hypokalemia with 0.25 mmol/kg IV over 30 minutes, and that potassium levels should be monitored every 1-2 hours during active correction of acidosis 1

The American College of Physicians suggests that sodium bicarbonate should only be considered in patients with severe metabolic acidosis (pH <7.10) and hemodynamic instability, or in patients with life-threatening hyperkalemia (K+ >6.5 mmol/L with ECG changes) 5
The American Society of Nephrology recommends that sodium bicarbonate should not be given to patients with acidosis due to hypoperfusion if the pH is ≥7.15, and that it should not be given without adequate ventilation 5

The American College of Critical Care Medicine recommends that patients with severe metabolic acidosis should have arterial blood gas analysis every 1-2 hours during active correction, as well as monitoring of serum electrolytes (Na+, K+, Cl-, Ca2+ ionized) every 1-2 hours 1, 5
The American Heart Association suggests that patients with severe metabolic acidosis should have continuous cardiac monitoring to detect arrhythmias due to hypokalemia, as well as continuous blood pressure monitoring (invasive preferred) 4

The American Thoracic Society recommends that the goal of oxygen therapy should be to achieve a SatO2 of 94-98% (or 88-92% in patients with severe COPD) 2
The American College of Cardiology suggests that the goal of pH correction should be to achieve a pH of 7.2-7.3 (without complete normalization initially) 5
The American College of Surgeons recommends that the goal of potassium correction should be to achieve a K+ level of 3.5-5.0 mEq/L with close monitoring 1
The American Heart Association suggests that the goal of blood pressure management should be to achieve a mean arterial pressure of >65 mmHg 4
The American College of Physicians recommends that the goal of urine output should be to achieve a gasto urinario of >1 mL/kg/hour 1