Mirro R, Milley J R, Holzman I R
Pediatr Res. 1985 Jan;19(1):15-8. doi: 10.1203/00006450-198501000-00005.
Vasodilators are used in newborns under conditions where hypoxia may be prominent. To study the effects of vasodilator therapy on organ oxygen delivery we measured blood flow (using radioactive microspheres) and arterial oxygen content in six chronically catheterized newborn lambs. Cardiac output and its distribution were measured during normoxia, hypoxia (10% O2 and 5% CO2), and hypoxia with a nitroprusside infusion. Hypoxia decreased oxygen content but did not change heart rate, mean blood pressure, or cardiac output. When nitroprusside was infused during hypoxemia, oxygen content and heart rate were not affected, but mean arterial blood pressure fell (39% decrease). During hypoxemia, blood flow increased to the heart, brain, and carcass but decreased to the gastrointestinal tract. When nitroprusside was infused during hypoxemia, blood flow decreased to the heart, brain, kidneys, and carcass. Oxygen delivery (arterial O2 content X blood flow) decreased to the brain as well as to kidneys, stomach, and carcass when nitroprusside was given to the hypoxemic lamb.
血管扩张剂用于缺氧可能较为突出的新生儿。为了研究血管扩张剂治疗对器官氧输送的影响，我们在六只长期插管的新生羔羊中测量了血流量（使用放射性微球）和动脉血氧含量。在常氧、缺氧（10%氧气和5%二氧化碳）以及缺氧并输注硝普钠的情况下测量心输出量及其分布。缺氧降低了氧含量，但未改变心率、平均血压或心输出量。当在低氧血症期间输注硝普钠时，氧含量和心率未受影响，但平均动脉血压下降（降低39%）。在低氧血症期间，心脏、大脑和躯体的血流量增加，但胃肠道的血流量减少。当在低氧血症期间输注硝普钠时，心脏、大脑、肾脏和躯体的血流量减少。当给低氧血症的羔羊输注硝普钠时，大脑以及肾脏、胃和躯体的氧输送（动脉血氧含量×血流量）减少。
