Management of Severe Metabolic Acidosis

Initial Assessment and Stabilization

The British Thoracic Society recommends ensuring adequate airway protection in patients with severe metabolic acidosis and altered mental status, as indicated by drowsiness, to prevent compromise of airway protection while on BiPAP 1, 3
Obtaining arterial blood gas (ABG) measurements is crucial to confirm the severity of acidosis and guide management, according to the British Thoracic Society 3
The British Medical Journal suggests assessing for signs of shock, including delayed capillary refill time, tachycardia, altered peripheral pulse volume, and cool extremities, in patients with severe metabolic acidosis 4

The European Respiratory Society recommends immediate intubation and invasive mechanical ventilation in patients with severe metabolic acidosis (pH 7.1) and altered mental status, as BiPAP is likely to fail 2
Initial ventilator settings should include tidal volumes of 6-8 mL/kg, respiratory rate of 10-15 breaths/minute, I:E ratio of 1:2-1:4, and target SaO2 88-92%, according to the British Thoracic Society 5
Permissive hypercapnia with a pH target of 7.2-7.4 is recommended by the British Thoracic Society 5

The British Medical Journal suggests administering 20-40 mL/kg of crystalloid fluid to correct hypovolemia, as this can safely improve hemodynamics and renal function in patients with severe metabolic acidosis 4
Monitoring urine output (target >1 mL/kg/hour) is essential to guide adequate fluid resuscitation, according to the British Medical Journal 4

The American Thoracic Society recommends checking lactate levels to identify lactic acidosis as a potential cause of elevated anion gap (19) in patients with severe metabolic acidosis 6
Considering toxicology screening for toxic ingestions is crucial in patients with severe metabolic acidosis and elevated anion gap, according to the American Thoracic Society 6
Empiric treatment for cyanide poisoning with hydroxocobalamin should be considered in patients with severe metabolic acidosis (pH <7.2) and a history of house fire, as recommended by the American Thoracic Society 6

Serial ABGs should be performed to assess response to therapy within 1-2 hours of intervention, according to the British Thoracic Society 3
Continuous monitoring of vital signs, oxygen saturation, and mental status is essential in patients with severe metabolic acidosis, as recommended by the British Thoracic Society 3

The British Thoracic Society recommends avoiding rapid normalization of CO2 in patients with COPD to prevent post-hypercapnic alkalosis 5
In patients with severe acidosis who self-ventilate to very low PCO2 levels, avoiding rapid rise in PCO2 during mechanical ventilation before acidosis is partially corrected is crucial, according to the British Medical Journal 4
Advanced age alone should not preclude aggressive management of severe metabolic acidosis, as stated by the British Thoracic Society 3

Delaying intubation in patients with severe acidosis (pH 7.1) and altered mental status on BiPAP increases mortality, according to the British Thoracic Society 3
Continued use of non-invasive ventilation when the patient is deteriorating rather than escalating to invasive mechanical ventilation increases mortality, as recommended by the British Thoracic Society 3