Patients with Chronic Paralytic/Restrictive Ventilatory Dysfunction: Discussion (4)
Systolic and diastolic blood pressures increase an average of 25 percent with apneas, with the rise being proportional to the severity of dSa02. Various cardiac arrhythmias occur in over 80 percent of OSAS patients. Premature ventricular contractions have been reported to increase threefold when Sa02 is less than 60 percent. Prolonged apneas with severe hypoxemia, particularly during REM sleep, appear to contribute to the significantly increased nocturnal mortality in patients with OSAS. Untreated patients with an apnea index greater than 20 had an eight-year mortality of 37 percent, compared with 4 percent for those with an index under 20. Chronic sympathetic stimulation due to chronic hy-percapnia and acidosis, particularly at Sa02 levels less than 90 percent, is associated with right ventricular strain, cor pulmonale, and chronic systemic hypertension. The cardiovascular stresses that apply to OSAS patients may apply to BV users. This deserves further study. buy birth control online
Transitory systemic hypertension occurs in many patients with acute poliomyelitis. For postpolio patients, however, a 22 percent incidence of hypertension (blood pressure >140/95 mm Hg) was reported by Kohn and Reid in 175 patients. They reported that the incidence correlated with the degree of respiratory muscle involvement, but not with ventilatory assistance. Their figures and the incidences reported in our study population of BV users do not vary significantly from those reported for the general population. The normalization of the blood pressures of five of the BV users after switching to the more effective NV-PAP, however, suggests that our patient population may have been too small for the results to reach statistical significance and that, at least for some patients, chronic blood gas disturbances or other effects associated with BV use itself may result in systemic hypertension.