Non-invasive cardiac monitor use in Obstetric patients - Hemodynamic Changes Associated with Spinal Anesthesia for Cesarean Delivery
Abstract Number: 190
Abstract Type: Original Research
Hypotension during spinal anesthesia remains a common clinical problem during C-sections. If hypotension is not resolved maternal complications of nausea and vomiting can occur, with decreased consciousness, aspiration and rarely cardiac arrest if hypotension is prolonged. Hypotension can also lead to reduced placental blood flow compromising the fetus. Heart rate and blood pressure are common variables monitored and used as surrogates for maternal cardiac output (CO), which better reflects uteroplacental blood perfusion (1). Non invasive cardiac output monitors (NICOM) utilize bioreactance to measure CO, and have been used successfully in cardiac patients (2). We report the first description of bioreactance NICOM monitoring in a case series of parturients during C-section, with good success.
After IRB approval, a retrospective review of 10 randomly selected healthy parturients who received spinal anesthesia for elective C-section was performed. Hemodynamic variables collected by NICOM, were analyzed pre spinal (baseline), 1 min. intervals post spinal up to 10 min. or until fetus delivery, 1 min. intervals after fetus delivery or until delivery of placenta, and 1 min. intervals after placenta delivery up to 20 min.
The changes in each variable; systolic/diastolic blood pressure (SBP/DBP), heart rate (HR), cardiac output/index (CO/CI) and stroke volume index (SVI) are summarized in table 1, for each significant event during the C-section (e.g. before/after spinal dosing, before/after fetus delivery and before/after placental delivery).
Bioreactance NICOM was shown to be an easy to use monitor during C-sections whilst providing valuable additional hemodynamic information during surgery. The profile of each variable added to the picture of the hemodynamic status of the patient, and provided information that could be used in clinical management decisions. Routine use of NICOM in all C-section patients should be considered, especially in high risk obstetric patients where early intervention for developing hypotension is critical.
1. van Huisseling H, Muijsers GJ, de Haan J, Hasaart TH. The acute response of the umbilical artery pulsatility index to changes in blood volume in fetal sheep, EJOG 1992 43 (2):149-155.
2. Squara P, Denjean D, Estagnasie P, Brusset A, Dib JC, Dubois C, Noninvasive cardiac output monitoring (NICOM): a clinical validation, Int. Care Med. 2007 33(7):1191-4.