During pregnancy, physiologically, there is a progressive adaptation of the maternal cardiovascular system for proper fetal development. Hemodynamic changes occur related to cardiac output and systemic vascular resistance. In the caesarean delivery undergoing subarachnoid anesthesia, these changes are accentuated due to the sympathetic blockade established, which may lead to hyper or hypodynamic states.  

The ClearSight® is a continuous non-invasive monitoring system that allows to know the baseline hemodynamic status of the patient and optimize the use of fluids and vasopressors, which was performed empirically until now. In this way we can prevent the signs and symptoms of hypotension that can appear because of the sympathetic blockade of the subarachnoid anesthesia, to the blood loss after delivery or to the administration of uterotonics.  

The goal of this preliminary study is to describe the hemodynamic changes produced in pregnant women undergoing non-emergent caesarean delivery with subarachnoid anesthesia. A prospective study of 20 patients monitored by ClearSight® during the entire intervention was carried out. Instead of hemodynamic parameters, we collected Apgar, pH and fetal oxigen saturation, fluids, type and doses of vasopressors. It was observed that the 100% had a baseline cardiac index> 3.5 l/min/m2. After performing the subarachnoid anesthesia, 10% had a cardiac index <3.5 l/min/m2. On the other hand, we observed a 5% of patients with an IC< 3.5 l/min/m2  after fetal extraction, and other 5% with administration of uterotonics. Until today, the vasopressor of choice has been phenylephrine, since ephedrine can produce fetal acidosis. Nevertheless ephedrine was used as a vasopressor in patients with a low cardiac index, since it is known that phenylephrine decreases cardiac output. Using phenylephrine in these patients could aggravate the hemodynamic status in case of hypodinamia and it could affect the uteroplacental perfusion and fetal well-being. 

In conclusion, despite of there is a small percentage of hypodinamic states during pregnancy, using a non-invasive and continuous monitor system we can detect it and choose the best therapy in order to guarantee the cardiac output and fetal well-being. More randomized prospective studies with adequate n are needed to confirm these first results.


03 / Hemodynamic optimization with non-invasive continuous monitoring system in non-emergent caesarean delivery undergoing subarachnoid anesthesia.