Response of Blood Gases and MVV to Abdominal Muscles Stimulation in Emphysema

A thirty subjects with emphysema participated in this study, after giving a written informed consent, in order to investigate the changes that occur in the arterial blood gases and maximum voluntary ventilation ( MVV ) as a result of electrical stimulation for the abdominal muscles. The age of the subjects ranged between 55-70 years. None of the subjects complains of any disease that is contraindicated for the study. The patients performed 30 strong contractions per session consisting of 15-seconds current stimulating period, followed by 50 seconds of rest, and completed a total of 24 sessions, three per week for eight weeks. Arterial blood gases and maximum voluntary ventilation ( MVV ) were measured before the first session and then after completion of eight weeks of stimulation. The results showed that there is a significant increase in arterial oxygen tension, a significant decrease in arterial carbon dioxide tension, a significant increase in arterial pH, and a significant increase in maximum voluntary ventilation after abdominal electrical stimulation in cases of emphysema. This improvement may be due to that the mean ventilationperfusion ratio of both blood flow and ventilation distributions shifted to higher values because of the greater increase in minute ventilation and also due to sufficient increase in overall ventilation.