Keiya Fujimori

Effects of Extracorporeal Membrane Oxygenation (ECMO) on Fetal Lambs

The purpose of this study was to determine the applicability of using ECMO techniques to support fetal oxygenation while maintaining fetal circulation in utero. Extracorporeal membrane oxygenation (ECMO) was applied to four chronically instrumented fetal lambs with the placental circulation intact. Blood was obtained through a catheter (2.5 mm ID) inserted into the right atrium and was returned to the carotid artery after oxygenation (V-A ECMO). The rate of blood flow varied from 200 to 300 mL/min (80-100 mL/kg/min). Compressed air at 2 L/min was used to ventilate the membrane, achieving the mean pO2 of 36.1 ± 9.5 torr in the blood after the membrane. A positive linear correlation was observed between pre-membrane and post-membrane pO2. Despite maternal hypoxia experimentally produced by reducing FiO2 of the mother for 15-35 min, V-A ECMO successfully maintained fetal blood pH and gases within the normal control range. These data indicate that V-A ECMO can effectively oxygenate lamb fetuses

Distribution of oxygenated blood flow at three different routes of extracorporeal membrane oxygenation in exteriorized fetal lambs

Objective: The purpose of this study was to determine which extracorporeal membrane oxygenation (ECMO) route best approximates the normal physiologic pattern of oxygenated blood distribution in fetal lambs submerged in warm saline solution.

Effects of Exogenous Vasopressin on Electrocortical Activity in the Fetal Lamb

We evaluated the effects of exogenous arginine vasopressin on electrocortical activity in the fetal lamb. Eight experiments were conducted on 5 chronically instrumented fetal lambs. Arginine vasopressin was infused at the rate of 1.56-2.27 mlU/min/kg estimated fetal weight for 30 min. Fetal electrocortical activity was obtained by 2 stainless steel screw electrodes implanted bilaterally on the fetal parietal skull. A significant increase was seen in the number of times that electrocortical activity switched from low voltage to high voltage and from high voltage to low voltage. The mean duration of the low voltage state was significantly decreased, while the duration of high voltage remained the same. The percentage of time that fetuses spent in the low voltage state was significantly decreased and in the high voltage state was significantly increased. In conclusion, exogenous AVP affects the regulation of fetal electrocortical activity, including the frequency of switching from one electrocortical activit...

Sporadic fetal heart rate decelerations associated with electrocortical changes in fetal lambs

Aim:  The purpose of this study was to determine a relationship between sporadic fetal heart rate (FHR) decelerations and fetal electrocortical changes in physiologically normal sheep fetuses.