Authors: Ben Marzouk S et al.
International Journal of Obstetric Anesthetic Vol 66 May 26 Clinical trial registration: NCT07108881
Summary
This randomized controlled trial evaluated whether cardiac ultrasound–guided crystalloid preloading, added to standard coloading, reduces the incidence and severity of maternal hypotension following spinal anesthesia for scheduled cesarean delivery. Maternal hypotension remains a frequent complication of spinal anesthesia, with potential adverse maternal and neonatal consequences. While crystalloid coloading is generally favored over preloading, a one-size-fits-all approach may be suboptimal in preload-dependent patients.
Ninety-six ASA II women with singleton pregnancies scheduled for elective cesarean delivery were enrolled. All patients were identified as preload dependent using cardiac ultrasound, defined as a ≥12% increase in left ventricular outflow tract velocity–time integral following passive leg raising. Participants were randomized to receive either ultrasound-guided, titrated crystalloid preloading in 250 mL increments until preload dependence resolved, followed by standard coloading, or standard coloading alone.
The incidence of hypotension after spinal anesthesia was significantly lower in the ultrasound-guided preload group compared with controls. In addition, hypotension episodes were shorter in duration, the nadir systolic blood pressure was higher, and rescue crystalloid requirements were reduced. Maternal nausea and vomiting occurred less frequently in patients who underwent preload correction. Although ephedrine use and cardiac output did not differ between groups, neonatal outcomes favored the preload-guided group, with higher umbilical artery pH values observed.
These findings suggest that identifying and correcting preload dependence before spinal anesthesia can improve maternal hemodynamics and reduce side effects without increasing vasopressor use. The authors propose that integrating focused cardiac ultrasound into obstetric anesthesia workflows may allow individualized fluid management rather than reliance on empiric coloading strategies alone.
Key Points
Preload dependence can be identified using bedside cardiac ultrasound before spinal anesthesia
Ultrasound-guided crystalloid preloading reduces the incidence and duration of maternal hypotension
Rescue crystalloid requirements and maternal nausea/vomiting were decreased
Umbilical cord pH was modestly improved with preload correction
Individualized fluid strategies may outperform standard coloading alone in selected patients