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T Nagaro

Publications and source records attributed to T Nagaro.

44 records · Page 3Linked to original sources
PubMed1984

Cerebral blood flow during conventional, new and open-chest cardio-pulmonary resuscitation in dogs.

The following parameters were monitored simultaneously in 15 dogs, in order to evaluate the efficacy of conventional CPR (C-CPR), new CPR (N-CPR), and open-chest CPR (O-CPR) on cerebral perfusion: arterial blood pressure (BP), central venous pressure (CVP), intrathoracic airway pressure, blood flow in carotid artery, intracranial pressure (ICP), sagittal sinus blood flow (sinus BF) and pressure (sinus P), and blood flow in cerebral cortex (cortical BF). The sinus blood flow was measured by the direct-method and with a cannulating electromagnetic flowmeter. The cortical blood flow was measured with a termocouple tissue flowmeter. Intracranial pressure was obtained by measuring subarachnoid cerebrospinal fluid pressure. Ventricular fibrillation was induced electrically. Chest compression and ventilation were always done manually in all cardiopulmonary resuscitation. The mean blood pressures during C-CPR, N-CPR and O-CPR were 52, 68 and 95 mmHg, respectively, and mean carotid blood flows per stroke were 36, 71 and 131% of the control values, respectively. The intracranial pressures were 30, 42 and 36 mmHg, respectively, giving the calculated cerebral perfusion pressures (BP-ICP) of 22, 27 and 60 mmHg, respectively. This should have been reflected in cerebral blood flow. Sinus blood flows/min were 18, 18 and 42%, and sinus blood flows per stroke were 55, 45 and 127% of control values, respectively; the differences between C-CPR and N-CPR were not significant. This was also true for cortical blood flow. From this we conclude that, firstly, N-CPR is not significantly better than C-CPR in cerebral perfusion because of its accompanying high intracranial pressure, secondly, O-CPR is far superior to the other two methods in respect of cerebral perfusion.

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PubMed1981

Blood-brain barrier impairment after cardiac resuscitation.

The influence of CPR on the blood-brain barrier (BBB) in dogs was studied by fluorescence microscopy using Evans blue as a BBB tracer. Three of 9 control dogs, whose blood pressure (BP) was increased by more than 130 mm Hg, showed dye extravasation (BBB impairment) into brain tissue, but no extravasation was seen in the other 6 controls whose BP increase was less than 110 mm Hg. In 11 experimental animals, extravasation of Evans blue occurred in 8 of 9 resuscitated dogs after several minutes of cardiac arrest and in 1 of 2 nonresuscitated dogs. In the resuscitated dogs, the maximum systolic BP (peak BP) after restoration of ventricular function ranged from -40 to +210 mm Hg compared to control values. They showed all grades of dye extravasation without significant correlation between the magnitude of BP increase and the severity of dye extravasation. The authors conclude that BBB disruption usually occurs during CPR and causes plasma protein extravasation into brain tissue. Arterial hypertension is a causative factor for BBB disruption, as was seen in the control dogs. In resuscitation, restoration of BP sufficient to overcome intracranial pressure and maintain cerebral blood flow may be high enough to induce BBB disruption because cerebral vessels are fully dilated and functionally impaired due to longstanding anoxia. The rapidity of BP increases after restoration of ventricular function could be another factor which might contribute to BBB impairment.

Animals↗