Stroke Volume Recruitability during the Third Trimester of Pregnancy

Abstract

In healthy term pregnancy, the heart operates in the ascending portion of the Starling's curve, rendering it fluid responsive.

Can ultrasonographic measurement of respiratory variability in the diameter of the internal jugular vein and the subclavian vein predict fluid responsiveness in parturients during cesarean delivery? A prospective cohort study

“…Fluid management is one of the most important methods to stabilize hemodynamics in parturients undergoing cesarean delivery. At present, many dynamic metrics have been used to predict volume reactivity and guide fluid therapy [ 17 ] and several noninvasive ultrasound technologies such as IVC-CI and the respiratory variability of superior vena cava diameter (SVC-CI) have been confirmed to accurately reflect fluid responsiveness in mechanically ventilated patients [ 3 , 14 , 18 ]. Unfortunately, the major intra-thoracic or intra-abdominal veins, such as IVC and SVC are technically difficult to visualize by transthoracic ultrasound and may not predict fluid responses during cesarean section for some reasons.…”

“…Importantly, echocardiography has been shown to assess fluid responsiveness by viewing the internal structure and the blood flow of the heart and great vessels and to guide fluid resuscitation in critically ill patients [ 1 , 2 ]. Unfortunately, both the compression of the inferior vena cava by the pregnant uterus and the technical difficulty in identifying by ultrasound limit the widespread use of the respiratory variability of deep abdominal and thoracic veins, such as superior vena cava (SVC) to predict fluid reactivity during cesarean section [ 3 , 4 ]. Interestingly, present evidence has shown that when compared with respiratory variability of inferior vena cava diameter (IVC-CI), respiratory variability of internal jugular vein variability (IJV-CI) and subclavian vein (SCV-CI) appear to be the suitable metrics of fluid responsiveness in spontaneously breathing patients with sepsis and acute circulatory failure [ 1 , 5 , 6 ].…”