Changes in Systemic Hemodynamics in Orthostasis in Patients With Long-Term Impairment of Consciousness

Abstract

The purpose of the study: to study hemodynamic parameters and the degree of its orthostatic stability during verticalization in patients with long-term impairment of consciousness in post-comatose period of brain damage.Materials and methods. This study included 30 patients with long-term impairment of consciousness caused by severe brain damage (Group 1), 10 of whom were in a vegetative state (VS) and 20 patients had a minimally conscious state (MCS). A severe traumatic brain injury was the most frequent cause of long-term disorders of consciousness (53.3%), other causes were associated with severe disorders of cerebral circulation (13.4%) and following consequences: rupture of cerebral aneurysms (10%), or post-hypoxic brain damage (10%), or removal of brain tumors (13.3%). The second group was comprised of 24 patients with local neurological symptoms after cerebral circulation disorders. The third group included 40 healthy volunteers. Systemic hemodynamic parameters were monitored using a multifunctional monitor TFM 3040i (CNSystem Austria) . Blood pressure (BP), heart rate (HR), stroke volume (SV), cardiac output (CO), and total peripheral resistance (TPR) were measured in real time. The statistical analysis was carried out using the Statistica-10 software package.Results. 26 patients of the first group (86%) demonstrated satisfactory hemodynamic stability in the tilt test at 30° and 60°; 3 patients of this group presented signs of orthostatic hypotension and 1 patient developed postural orthostatic tachycardia syndrome (SPOT) when tilted by 30°. A comparative analysis of hemodynamic parameters in patients of the first and second groups did not demonstrate significant differences, except for significantly higher HR values and lower SV values in the first group. Parameters of systemic hemodynamics in the horizontal position were significantly different in healthy volunteers, and were characterized by higher SV and CO values and lower BP, HR and TPR values as compared to patients of groups 1 and 2.Conclusion. This study demonstrated a hypokinetic type of blood circulation in all patients with brain lesions; it was more severe in patients with long-term impaired consciousness after severe brain damage. The majority of patients in this group presented satisfactory orthostatic hemodynamic stability; different types of orthostatic disorders were found in 14% of cases. A passive orthostatic test (0—30—60°) applied in this study allowed to diagnose orthostatic disorders at a slight tilt up to the onset of clinical symptoms of brain hypoperfusion. This indicates the need for hemodynamic monitoring in the early stages of patients' verticalization.

Keywords

• vegetative state
• minimally conscious state
• passive orthostatic test
• systemic hemodynamics