The Management of Chronic Hypoventilation: Diagnostic Evaluation (4)
The above studies will define the pathophysiology and identify reversible contributing factors in most patients with chronic hypoventilation, but some additional studies may occasionally be useful. Measurement of transdiaphragmatic pressures using gastric and esophageal balloons is useful in confirming the diagnosis of bilateral diaphragmatic paralysis. We have not found C02 or hypoxic ventilatory response curves to be helpful in patients with chronic hypoventilation because chronic C02 retention blunts respiratory center responsiveness to C02 and the results of studies are almost invariably abnormal. buy ampicillin
Therapy of Chronic Hypoventilation Overall Approach
The first step in treating a patient with chronic hypoventilation is to treat reversible factors that have been identified in the course of the examination. Reversal of airway obstruction using bronchodilators or steroids, treatment of congestive heart failure with diuretics, and correction of metabolic alkalosis may be the only interventions necessary to normalize ventilation. Hypothyroidism, hypophosphatemia, and hypomagnesemia are less often encountered, but adequate therapy for them may be equally efficacious. Drugs such as benzodiazepines or narcotics are uncommon causes of chronic hypoventilation in otherwise normal individuals, but they may be contributory in patients with compromised pulmonary function or central drive defects, and they should be avoided when feasible.