Studies on status asthmaticus in children. I. Capillary blood pH and pCO-2 in status asthmaticus

Lactic acidosis and status asthmaticus: how common in pediatrics?

BACKGROUND

Lactic acidosis is a well described phenomenon in adult patients with severe asthma. However, this entity is rarely reported in children with status asthmaticus.

OBJECTIVE

To report our experience in a 13-year-old girl who developed lactic acidosis as a complication of status asthmaticus and to investigate the prevalence of this complication of severe asthma. We sought to determine the frequency of lactic acidosis in such patients and to review etiologies of lactic acidosis.

METHODS

1) Observations on the clinical and laboratory findings in an adolescent girl with status asthmaticus who developed lactic acidosis were recorded. 2) The medical records of 100 children and adolescents with status asthmaticus admitted to an intensive care unit were reviewed for laboratory evidence of lactic acidosis. 3) We also reviewed our own previous experience of status asthmaticus with respiratory failure.

RESULTS

Among 100 patients admitted to a pediatric intensive care unit for status asthmaticus, a single case of isolated metabolic acidosis was identified. This proved to be attributable to lactic acidosis. When records of patients with severe respiratory failure were examined, no cases of metabolic acidosis were found.

CONCLUSIONS

Although rare, lactic acidosis does occur in pediatric-aged patients during status asthmaticus. It is important that this complication be recognized and treated because acidosis may inhibit the effectiveness of bronchodilator therapy, produce electrolyte disturbances, and cause serious adverse effects on the patient's cardiovascular system.

The role of pulmonary hypertension in the pathogenesis of bronchial asthma

In patients with bronchial asthma, when blood pressure in the pulmonary artery is measured, very often hypertension is registered. This pulmonary hypertension is not secondary to hypoventilation, as in patients with chronic bronchitis or pulmonary emphysema, since patients with bronchial asthma are hyperventilating. The pulmonary hypertension in them must be therefore classified as primary. It is probable that its origin is in an allergic vasoconstriction of the pulmonary artery, occurring simultaneously with the well known bronchoconstriction.

Arterial blood gas tensions and pH in acute asthma in childhood

Studies of the arterial blood gas tensions and pH in 21 children during 24 acute attacks of asthma showed that all were hypoxic on admission to hospital, and in 10 there was evidence of carbon dioxide retention. Cyanosis, invariably present when the So(2) was below 85%, and restlessness in patients breathing air were the most reliable indices of the severity of hypoxia. There were no reliable clinical guides to the Pco(2) level. Conventional oxygen therapy in tents (25-40%) did not always relieve hypoxia, and in three cases the administration of oxygen at a concentration of 40% or over failed to produce a normal arterial oxygen tension. Uncontrolled oxygen therapy may aggravate respiratory acidosis, and three of our patients developed carbon dioxide narcosis while breathing oxygen. The necessity for blood gas measurements in the management of severe acute asthma in childhood is emphasized.

Childhood status asthmaticus. Recent clinical and laboratory observations and their application in treatment

The complications of bronchial asthma are increasing. This paper presents clini cal and laboratory data obtained from a group of children admitted in status asthmaticus to Children's Hospital of Philadelphia and describes in detail the program of management which emerged from study of these data. Speculations are also made regarding the pathophysi ology of this illness.