It has often been pointed out that introduction of early rehabilitation programs may convey a considerable risk of cerebral hypoperfusion, presumably due to dysautoregulation. Cerebral blood flow (CBF) was measured in six patients with cerebrovascular disease using ^99mTc-hexamethyl propyleneamine oxime single photon emission computed tomography (99^mTc-HM-PAO-SPECT) to investigate whether warm bathing with CO₂ bubble stimulation (CO₂ bathing) can be applied to early rehabilitation programs. The subjects comprised two patients with hypertensive cerebral hemorrhage, two with aneurysmal subarachnoid hemorrhage, and two with cerebral infarction. CO₂ bubble stimulation was produced by dissolving 100g of commercially available CO₂ bubble forming tablets in 300L of warm water (41°C) and a course consisting of 10 minutes of CO₂ bathing was applied for seven days. Vital signs such as blood pressure, pulse rate, and body temperatures at the axilla and the external auditory canal adjacent to the ear drum were checked during each bathing. CBF measurements and routine laboratory examinations were made before and after the seven-day course of CO₂ bathing. Student-t test was used for statistical analysis.
No definite changes were shown in vital signs before and after CO₂ bathing. A significant decrease in WBC counts was observed after CO₂ bathing, but there were no changes in values of C-reactive protein. Although no significant changes in hemisphere CBF were identified, actual values of regional CBF in the unaffected hemisphere tended to increase in two patients.
These results suggest that CO₂ bathing produces no adverse effects on cerebral perfusion and can be applied safely to early rehabilitation programs.