Respiratory acidosis and alkalosis in children

Abstract

<h2>Summary</h2> Respiratory acidosis and alkalosis occur probably more frequently than isgenerally believed and should be considered in patients presenting derangements of the respiratory mechanism. Cases illustrating the two conditions are presented. The diagnoses of respiratory acidosis and alkalosis are dependent not only on determinations of total plasma carbon-dioxide content but also of plasma pH. Whereas, in metabolic acidosis there is a correlation between the decrease in plasma carbon-dioxide content or alkali reserve and degree of acidosis, in respiratory acidosis there may be a normal or an increased plasma carbondioxide content with a decrease in pH. An opposite reversal is present in respiratory alkalosis, where plasma carbon-dioxide content may be decreased or remain normal with plasma pH definitely elevated. The mechanism whereby these changes occur may be as is shown in Table I. With the respiratory system deranged, as is the case in respiratory acidosis or alkalosis, the burden of maintaining a normal plasma pH falls more heavily on the renal mechanism. Compensation for increased or decreased H.HCO₃ is attempted by altering the B.HCO₃ so as to maintain a 1:20 ratio and thus a plasma pH of 7.4. The increase or decrease of B.HCO₃ seems to occur through an increase or decrease of the chloride excretion. However, compensation is usually not complete and an abnormal plasma pH persists. Efforts to increase the renal mechanism of compensation appear inadequate and it seems that the treatment of respiratory acidosis and alkalosis had best be directed toward the correction of the underlying pathology which is responsible for the derangement of the respiratory system.