title: The association between thromboelastographic parameters and total estimated blood loss in patients undergoing elective cesarean delivery.
abstract: BACKGROUND
  In this study, we assessed the relationship between coagulation parameters using kaolin-activated thromboelastography (TEG®) and total estimated blood loss (EBL) in patients undergoing elective cesarean delivery (CD).
  
  
  METHODS
  TEG® parameters were recorded in 52 patients before and after elective CD. Laboratory markers of coagulation (prothrombin time, activated partial thromboplastin time, fibrinogen) were also assessed in a smaller subset (21 patients). Correlation and linear regression analysis was used to assess the relationship among TEG® parameters, relevant clinical variables, and total EBL. Secondary analysis included comparisons of TEG® and coagulation profiles pre-CD versus post-CD.
  
  
  RESULTS
  EBL weakly correlated with percentage change in maximum amplitude (r=0.3; P=0.04) and post-CD maximum rate of thrombus generation (r=0.31; P=0.02). Post-CD values for split point, reaction time, time to maximum rate of thrombin generation, prothrombin time, and activated partial thromboplastin time were significantly increased compared with baseline values (P<0.05). Post-CD α angle, maximum amplitude, total thrombus generation, fibrinogen, and platelet counts were significantly decreased compared with baseline values (P<0.05).
  
  
  CONCLUSIONS
  There is a weak association between clot strength (as assessed by kaolin-activated TEG®) and EBL in patients undergoing elective CD under neuraxial anesthesia, and a modest reduction in the degree of maternal hypercoagulability occurs in the early postpartum period after elective CD.
authors.affiliation: Department of Anesthesia (MC: 5640), Stanford University School of Medicine, 300 Pasteur Dr., Stanford, CA 94305, USA. ajbut@stanford.edu
authors.forename: Alexander
authors.initials: A
authors.lastname: Butwick
authors.forename: Vicki
authors.initials: V
authors.lastname: Ting
authors.forename: Lindsey Atkinson
authors.initials: LA
authors.lastname: Ralls
authors.forename: Scott
authors.initials: S
authors.lastname: Harter
authors.forename: Edward
authors.initials: E
authors.lastname: Riley
mesh_terms: D000328:Adult; D000773:Anesthesia, Obstetrical; D000775:Anesthesia, Spinal; D015415:Biomarkers / Q000097:blood; D001777:Blood Coagulation; D016063:Blood Loss, Surgical; D002585:Cesarean Section / Q000009:adverse effects*; D017558:Elective Surgical Procedures; D005260:Female; D005340:Fibrinogen / Q000378:metabolism; D006801:Humans; D007616:Kaolin; D016014:Linear Models; D015999:Multivariate Analysis; D010314:Partial Thromboplastin Time; D011184:Postoperative Period; D011237:Predictive Value of Tests; D011247:Pregnancy; D057234:Preoperative Period; D011517:Prothrombin Time; D018570:Risk Assessment; D012307:Risk Factors; D013916:Thrombelastography; D013997:Time Factors
chemical_list: D015415:Biomarkers; D007616:Kaolin; D005340:Fibrinogen