Postspinal hypotension (PSH) is a common side effect with an incidence of 15.3% to 33%, which may result in organ hypoperfusion and ischemic events (1,2). In pregnant patients, this incidence may increase to 70% and severe PSH may increase the risk of maternal and fetal complications (3). Therefore, it is important for anesthesiologists to estimate the incidence of PSH in cesarean sections and to identify possible mechanisms (4).

One of the important factors affecting the susceptibility of patients to intraoperative hypotension is the preoperative intravascular volume status. Recently, ultrasonography of the central veins has been used frequently by anesthesiologists in the preoperative period in order to evaluate the intravascular volume status (5). Salama and Elkashlan stated that the collapsibility index of the inferior vena cava is a new predictive value for PSH (6). Choi et al. showed that the subclavian vein or infraclavicular axillary vein collapsibility index is an important predictive value for hypotension after induction of general anesthesia (7).

In this study, we wanted to investigate whether the subclavian vein or infraclavicular axillary vein collapsibility index can be used as a predictive value for PSH in cesarean section.

Inclusion Criteria:

• Spinal anesthesia
• ceserean operation
• American Society of Anesthesiologists' (ASA) physical status I-II

Exclusion Criteria:

• Patients who underwent cesarean section in emergency conditions
• Patients who underwent cesarean section under general anesthesia
• American Society of Anesthesiologists' (ASA) physical status III-IV

ASA I-II physical status patients scheduled for cesarean section under spinal anesthesia