Blood Loss Measurement During Cesarean Delivery

This is an observational study. Potential participants will be approached by a member of the research team prior to surgery. Healthy ASA 1, 2, or 3 patients undergoing uncomplicated Cesarean delivery will be recruited. The Triton device will be used during the surgery to estimate blood loss. Specifically, the device takes pictures of the blood saturated laps and fluid collection canister and calculates hemoglobin loss and overall blood loss.

Serum hemoglobin samples will be collected at baseline on presentation to the pre-operative area, within 15 mins of arrival in PACU and at 24 hrs post cesarean delivery. Blood sampling will take place by venipuncture technique from a vein in the arm. Maternal vital signs during the perioperative period (heart rate, maternal mean arterial blood pressure, anesthetic technique, fluid administration, and surgical data will be recorded.

All patient will have a neuraxial anesthetic of a spinal or combined spinal/epidural. Fluid administration will be under the discretion of the anesthesiologist and will follow standard guidelines including 1L of Lactated Ringers co-load at time of spinal and 1-2L of crystaloid intraoperatively.

At the end of the cesarean section, the following measurements will be made:

• tEBL: Triton device will be used to measure blood loss on wet and dry soaked laps and in the suction canister. These measurements will be used to calculate tEBL.
• vEBL: The attending obstetrician and anesthesiologist will independently be asked to provide estimates for total blood loss (vEBL). We will use both values in separate regression analyses
• qEBL: Blood loss will be measured by cumulative measurement of the following: the volume of blood in the suction chamber at the end of surgery (and subtracting the estimated amniotic fluid from the suction chamber; weight of blood soaked laps; estimated spillage of blood (in ml) in and around the surgical field (not collected on laps or in suction chamber).

Using mixed effects modeling, we will determine whether estimated blood loss measurements using Triton (tEBL) can be used to predict postpartum hemoglobin (Hb) levels, after accounting for the predelivery Hb level, intraoperative intravenous fluids and patient/operative factors.

Inclusion criteria

• American Society of Anesthesiologists physical status class I-III
• undergoing Cesarean delivery under neuraxial anesthesia
• age between 18 and 50
• gestational age greater than or equal to 37 completed weeks
• all ethnicities

Exclusion criteria

• contraindication for epidural or spinal analgesia (bleeding diathesis, neuropathy, severe scoliosis, local anesthetic allergy)
• inability to adequately understand the consent form