Management of Low Carbon Dioxide Levels

Assessment and Monitoring

The American Academy of Pediatrics and the American Heart Association recommend monitoring end-tidal CO2 (ETCO2) as a non-invasive measure of CO2 levels, which correlates with arterial CO2 in most patients 1, 2
ETCO2 values may not accurately reflect arterial CO2 (PaCO2) in all clinical scenarios 2
Continuously monitor vital signs, including respiratory rate and pattern, using ETCO2 monitoring during resuscitation to assess cardiac output and effectiveness of chest compressions 1

Target normal CO2 levels (35-45 mmHg) unless specific conditions warrant different targets, as recommended by the American Heart Association 2
Patients with baseline chronic lung disease and chronic CO2 retention might respond differently to CO2 targets 2

The American Thoracic Society recommends targeting oxygen saturation of 88-92% in COPD patients to prevent worsening CO2 retention, using controlled oxygen delivery via 24% or 28% Venturi masks or 1-2 L/min via nasal cannulae 5
Avoid excessive correction of low CO2, as rapid normalization can lead to cerebral vasoconstriction and neurological symptoms, and recognize that abrupt discontinuation of oxygen when hypercapnia is detected can cause rapid desaturation in COPD patients 3
In post-cardiac arrest patients, avoid both hypocapnia and hypercapnia as they may affect cerebral blood flow, as recommended by the American Heart Association 2
In carbon monoxide poisoning, administer 100% normobaric oxygen immediately while awaiting confirmation of diagnosis, as recommended by the American Thoracic Society 5