Showing papers by "James B. Skatrud published in 2015"

Determinants of hypoventilation during wakefulness and sleep in diaphragmatic paralysis

Abstract: A 45-yr-old man with limb girdle muscular dystrophy, bilateral diaphragmatic paralysis, chronic carbon dioxide retention, and hypersomnolence was studied to determine the causes of hypoventilation during wakefulness and during sleep. Awake hypoventilation was associated with an insufficient inspiratory effort in the presence of inefficient respiratory muscles and a shortened inspiratory time. During sleep, severe hypoventilation and oxygen desaturation occurred only during REM-induced intercostal and accessory muscle inhibition.

Relative Effectiveness of Acetazolamide versus Medroxyprogesterone Acetate in Correction of Chronic Carbon Dioxide Retention1 ,2

Abstract: We compared the relative efficacy of normalization of plasma bicarbonate with acetazolamide (ACET) versus medroxyprogesterone acetate (MPA) in correcting chronic CO2 retention during waking and sleeping states in patients with chronic obstructive airway disease (COPD). During placebo period, inspiratory effort (P0.1,) was high but insufficient to raise minute ventilation () to the supernormal levels required for sufficient alveolar ventilation to normalize - Chronic ventilatory stimulation with either drug increased P0.1 (5 to 42%), mean inspiratory flow (14 to 31%), tidal volume (11 to 22%), and (16 to 19%) in 11 of 15 patients. This resulted in significant correction of their CO2 retention during waking and sleeping states ΔPaco2= -5 to -16 mmHg), despite the presence of high inspiratory impedance, shortened inspiratory time, and nonuniform ventilation-perfusion ratio. The acute ventilatory response to exogenous CO2 was not a good predictor of the chronic ventilatory response to MPA or even of the chron...