Pathophysiology and Management of Severe Asthma

Flexible Fiberoptic Bronchoscopy in the Intensive Care Unit

For the past 20 years, flexible fiberoptic bronchoscopy (FOB) has been shown to be an important procedure in the diagnosis and management of patients in intensive care units (ICU). In adults, FOB is used therapeutically to remove retained secretions and to correct atelectasis not improved by conservative means. In the pediatric population, however, FOB is mainly used to diagnose tracheal disease in critically ill children. The principal risks of FOB are hypoxemia and dysrhythmias; hemor rhage and pneumothorax may occur as a result of biopsy procedures. In competent hands, these adverse compli cations of FOB are minimal. Although rigid bronchos copy remains pivotal in most pediatric bronchoscopic procedures, massive hemoptysis, foreign body removal, and laser therapy for occluding tumors of the upper airway, flexible FOB has an increasingly important role in the diagnosis and management of these disorders.

Rhabdomyolysis following life-threatening acute asthma attack

The authors report a life-threatening, acute asthmatic attack in a young man, which was followed by rhabdomyolysis and acute myoglobinuria. A discussion of the possible rôle of the pharmacological treatment of asthma in initiating muscle damage is included, based on a review of the current literature.

Decreased paradoxic pulse from increased venous return in severe asthma

During severe asthma, paradoxic pulse may result from increased impedance to left ventricular ejection, mechanical impairment of left ventricular filling by ventricular interdependence or decreased pulmonary venous return augmented by hypovolemia. We studied the effect of reversible blood volume expansion by MAST inflation during severe attacks of asthma. Ten patients with clinically detectable paradoxic pulse of more than 20 mm Hg were studied. All had a history of reversible bronchial asthma with evidence of respiratory and circulatory failure. Standard therapy for asthma was started. We observed no difference in respiratory and heart rates during MAST inflation. Paradoxic pulse was consistently decreased during MAST inflation; paradoxic pulse returned to baseline values after MAST deflation. The decrease in paradoxic pulse was produced by an increased inspiratory systolic arterial pressure. We conclude that a reduction in pulmonary venous return is more important than ventricular interdependence in producing paradoxic pulse during severe asthma.

Status asthmaticus. Early institution of treatment

Advances in therapy of status asthmaticus have made death among hospitalized patients uncommon. The routine use of airflow measurements may help patients and physicians recognize increasing severity of asthma and react before symptoms worsen. Early recognition allows institution of effective therapy before critical airflow limitation has developed.