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Hemodynamic Impairment (hemodynamic + impairment)

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Medical Sciences	100%

Selected Abstracts

Reperfusion normalizes motor activation patterns in large-vessel disease,

ANNALS OF NEUROLOGY, Issue 2 2009
Mohamad Chmayssani MD
Objective Hemodynamic impairment in one hemisphere has been shown to trigger ipsilateral motor activation in the opposite hemisphere on functional imaging. We hypothesized that reversing the hypoperfusion would normalize the motor activation pattern. Methods We studied four patients with high-grade stenosis and impaired vasomotor reactivity (VMR) but no stroke. Functional magnetic resonance imaging motor activation pattern before and after VMR normalization was compared with seven healthy control subjects scanned at an interval of 3 months using voxel-wise statistical parametric maps and region of interest analysis. Subjects performed a repetitive hand closure task in synchrony with 1Hz metronome tone. We used repeated-measures analysis of variance to compute the interaction between group (patients/control subjects) and time by obtaining the average blood oxygen level dependent signal of three motor regions of interest in each hemisphere. Results Two patients normalized their VMR after spontaneous resolution of dissection, and two after revascularization procedures. Both voxel-wise statistical maps and region of interest analysis showed that VMR normalization was associated in each case with a reduction in the atypical activation in the hemisphere opposite to the previously hypoperfused hemisphere (p < 0.001). Interpretation In the presence of a physiological stressor such as hypoperfusion, the brain is capable of dynamic functional reorganization to the opposite hemisphere that is reversible when normal blood flow is restored. These findings are important to our understanding of the clinical consequences of hemodynamic failure and the role of the ipsilateral hemisphere in maintaining normal neurological function. Ann Neurol 2009;65:203,208 [source]

Hemodynamic effects of PEEP in a porcine model of HCl-induced mild acute lung injury

ACTA ANAESTHESIOLOGICA SCANDINAVICA, Issue 2 2009
C. K. MARUMO
Background: Positive end-expiratory pressure (PEEP) and sustained inspiratory insufflations (SI) during acute lung injury (ALI) are suggested to improve oxygenation and respiratory mechanics. We aimed to investigate the hemodynamic effects of PEEP with and without alveolar recruiting maneuver in a mild ALI model induced by inhalation of hydrochloric acid. Methods: Thirty-two pigs were randomly allocated into four groups (Control,PEEP, Control,SI, ALI,PEEP and ALI,SI). ALI was induced by intratracheal instillation of hydrochloric acid. PEEP values were progressively increased and decreased from 5, 10, 15 and 20 cmH2O in all groups. Three SIs maneuvers of 30 cmH2O for 20 s were applied to the assignable groups between each PEEP level. Transesophageal echocardiography (TEE), global hemodynamics, oxygenation indexes and gastric tonometry were measured 5 min after the maneuvers had been concluded and at each established value of PEEP (5, 10, 15 and 20 cmH2O). Results: The cardiac index, ejection fraction and end-diastolic volume of right ventricle were significantly (P<0.001) decreased with PEEP in both Control and ALI groups. Left ventricle echocardiography showed a significant decrease in end-diastolic volume at 20 cmH2O of PEEP (P<0.001). SIs did not exert any significant hemodynamic effects either early (after 5 min) or late (after 3 h). Conclusions: In a mild ALI model induced by inhalation of hydrochloric acid, significant hemodynamic impairment characterized by cardiac function deterioration occurred during PEEP increment, but SI, probably due to low applied values (30 cmH2O), did not exert further negative hemodynamic effects. PEEP should be used cautiously in ALI caused by acid gastric content inhalation. [source]

The effect of sildenafil citrate (Viagra) on cerebral blood flow in patients with cerebrovascular risk factors

ACTA NEUROLOGICA SCANDINAVICA, Issue 6 2010
M. Lorberboym
Lorberboym M, Mena I, Wainstein J, Boaz M, Lampl Y. The effect of sildenafil citrate (Viagra) on cerebral blood flow in patients with cerebrovascular risk factors. Acta Neurol Scand: 2010: 121: 370,376. © 2009 The Authors Journal compilation © 2009 Blackwell Munksgaard. Objectives,,, Sildenafil citrate is widely used for erectile dysfunction. The present study examined the short-term effects of sildenafil administration in individuals with cerebrovascular risk factors, including patients with a history of stroke. Materials and Methods,,, Twenty-five consecutive male patients with erectile dysfunction and vascular risk factors were included in the study. A perfusion brain SPECT study was performed at baseline and 1 h after the oral administration of sildenafil. Results,,, Associations between any of the risk factors and the perfusion scores were not detected, with the exception of stroke. Stroke patients showed significantly more areas with diminished perfusion after sildenafil administration compared to baseline. Conclusions,,, In patients with diabetes or hypertension, a dose of 50 mg sildenafil does not appear to produce detrimental effects on cerebral blood flow. However, patients with a history of stroke may be at increased risk of hemodynamic impairment after the use of sildenafil. [source]

Novel percutaneous catheter thrombectomy in acute massive pulmonary embolism: Rotational bidirectional thrombectomy (ROBOT)

CATHETERIZATION AND CARDIOVASCULAR INTERVENTIONS, Issue 1 2006
Masashi Yoshida MD
Abstract Background: Although thrombolysis is a standard therapy in cases of pulmonary embolism (PE), fatal outcome is often observed. We designed and investigated the efficacy of a novel percutaneous catheter therapy, rotational bidirectional thrombectomy (ROBOT), for PE. Methods and Results: Eighteen patients with acute massive PE (Miller score , 20) were included in this study. We separated them into two groups [group A (n = 10), thrombolysis; group B (n = 8): thrombolysis and ROBOT or ROBOT alone]. There was no difference in the hemodynamic indices between the groups at diagnosis. ROBOT was designed to fragment emboli by rotating a regular pigtail catheter. Three deaths occurred in group A because of hemodynamic impairment, but there was no death in group B. One day after treatment, systolic pulmonary artery pressure had decreased from 53 ± 8 to 30 ± 8 mm Hg (P < 0.05) in group B and from 54 ± 5 to 42 ± 19 mm Hg (NS) in group A. The hospitalization period in group B was shorter than that in group A (17 ± 6 vs. 27 ± 10 days, P < 0.05). Conclusion: ROBOT therapy results in a significant, rapid improvement in the hemodynamic situation and in a better outcome than conventional therapy in patients with acute massive pulmonary embolism. © 2006 Wiley-Liss, Inc. [source]