Mellander M, Larsson L E
Department of Pediatrics, Gothenburg University, Sweden.
J Pediatr. 1988 Jul;113(1 Pt 1):101-9. doi: 10.1016/s0022-3476(88)80542-0.
The effects of early left-to-right ductus shunting on left ventricular output (LVO) and cerebral blood flow velocity (CBV) were investigated in 3-day-old preterm infants by means of two-dimensional Doppler and M-mode echocardiography. Nineteen infants required mechanical ventilation because of severe lung disease (group A), and 19 had mild or no lung disease (group B). Six infants in each group had predetermined Doppler and M-mode criteria of a hemodynamically significant left-to-right ductus shunt (hsPDA). In group A the LVO was similar in infants with and without hsPDA, but those with hsPDA had lower mean arterial pressure (p = 0.006) and lower mean systolic-diastolic CBV (p = 0.001) than those without hsPDA. In group B the presence of hsPDA was associated with a higher LVO (p = 0.002), whereas neither mean arterial pressure nor mean systolic-diastolic CBV differed significantly in infants with and without hsPDA. In infants without hsPDA, those in group A had higher LVO (p = 0.012), lower mean arterial pressure (p = 0.003), and lower estimated systemic vascular resistance (p = 0.004) than those in group B. These results indicate that severely ill preterm infants receiving mechanical ventilation are less able than spontaneously breathing infants to defend systemic pressures and cerebral perfusion through an increase of LVO when a large ductus shunt develops. Possible reasons include an elevated baseline LVO, caused by systemic vasodilation, and hence a low preload reserve.
通过二维多普勒和M型超声心动图研究了3日龄早产儿早期从左向右的动脉导管分流对左心室输出量（LVO）和脑血流速度（CBV）的影响。19名因严重肺部疾病需要机械通气的婴儿（A组），以及19名患有轻度肺部疾病或无肺部疾病的婴儿（B组）。每组中有6名婴儿符合血流动力学显著的从左向右动脉导管分流（hsPDA）的预定多普勒和M型标准。在A组中，有hsPDA和无hsPDA的婴儿LVO相似，但有hsPDA的婴儿平均动脉压较低（p = 0.006），平均收缩-舒张期CBV低于无hsPDA者（p = 0.001）。在B组中，hsPDA的存在与较高的LVO相关（p = 0.002），而有和无hsPDA的婴儿平均动脉压和平均收缩-舒张期CBV均无显著差异。在无hsPDA的婴儿中，A组婴儿的LVO高于B组（p = 0.012），平均动脉压较低（p = 0.003），估计的体循环血管阻力较低（p = 0.004）。这些结果表明，接受机械通气的重症早产儿在出现大的动脉导管分流时，通过增加LVO来维持体循环压力和脑灌注的能力不如自主呼吸的婴儿。可能的原因包括全身血管舒张导致的基线LVO升高，从而导致前负荷储备降低。
