Ih. Gothgen et al., VENTILATION IN ARDS AND ASTHMA - THE OPTIMAL BLOOD-GAS VALUES, Scandinavian journal of clinical & laboratory investigation, 53, 1993, pp. 67-73
Artificial ventilation of patients with acute respiratory diseases, i.
e. ARDS and severe asthma, may involve the risk of pulmonary oxygen to
xicity as well as volutrauma. The relationship between ventilator trea
tment and volutrauma suggests that only in patients with normal lungs
the aim of ventilator treatment should be an arterial carbon dioxide t
ension and pH within the normal ranges. In patients suffering from a l
ung disease the clinical target must be based not only upon the arteri
al blood gases but also upon airway pressure and respiratory tidal vol
ume. Thus during artificial ventilation of a patient with an acute pul
monary disease the following arterial pH and pCO2 optima are proposed:
pH 7.35, with a range from 7.1 to 7.4; pCO2 is related to pH but an a
cceptable range is 5-12 kPa. The lowest acceptable fraction of inspire
d oxygen and thereby the safe lower level of arterial pO2 for an indiv
idual patient depends on many factors. The lower limit may be about 3
kPa, but the arterial pO2 should not be evaluated as an isolated param
eter. It is related to the general oxygen transport capability of arte
rial blood, extractable oxygen, cardiac output and the microcirculatio
n.