Original Contributions *Associate Professor of Anesthesiology †MPH Student, School of Public Health ‡Assistant Professor of Anesthesiology Address correspondent to Dr. Evan G. Pival- izza, Department of Anesthesiology, Univer- sity of Texas Health Science Center-Houston, MSB 5.020, 6431 Fannin, Houston, TX 77030. E-mail: Evan.G.Pivalizza@uth.tmc.edu Thrombelastograph R disposables were sup- plied by Haemoscope Corp., Skokie, IL Portions of this data were presented in ab- stract form at the Society of Pediatric Anes- thesia Annual Meeting, Tampa Bay, FL, Feb- ruary, 1996, and the American Society of Anesthesiologist’s Annual Meeting, Orlando, FL, October, 1998. Abstract published in Anesthesiology 1998;89:A1280. Received for publication August 29, 2000; revised manuscript accepted for publication December 6, 2000. Celite-Activated Thrombelastography in Children Evan G. Pivalizza, MBChB, FFASA,* Penelope J. Pivalizza, MD,† Lewis I. Gottschalk, MBChB, FFASA,‡ Spencer Kee, MBChB, FRCA,‡ Peter Szmuk, MD,‡ David C. Abramson, MBChB, FFASA* Department of Anesthesiology and School of Public Health, University of Texas Health Science Center-Houston, Houston, TX Study Objective: To quantify global coagulation and establish normal ranges for the celite-activated thrombelastograph R (TEG) in healthy pediatric patients. Design: Prospective observational study. Setting: Operating suite of a university-based hospital. Patients: 110 healthy pediatric patients in four age groups and 25 healthy adult patients. Interventions: Blood sampling for the celite-activated TEG was carried out after anesthetic induction. Measurements: TEG indices: R time (reflecting time to fibrin formation), K time and alpha angle (fibrinogen-platelet interaction), maximum amplitude (reflecting maximal clot strength, platelet and fibrinogen function), TEG index (mathematical incorporation of the prior four measurements), and percent fibrinolysis at 30 minutes, were all recorded. Main Results: Statistically significant differences between 12-month group in angle (compared to 25– 48 month group) and % fibrinolysis (compared to all other pediatric groups). Significant differences in angle between two pediatric groups and adult group, and in the TEG index between three pediatric groups and adult group (all differences p  0.05). Conclusions: These data identify changes of small magnitude in three celite-TEG parameters in healthy children compared to adults, without implication of abnormal coagulation between groups. Changes do not seem to be consistently related to age and will be useful for clinicians using the TEG to monitor (ab) normal coagulation in pediatric patients. © 2001 by Elsevier Science Inc. Keywords: Celite; children; Thrombelastograph R . Introduction The thrombelastograph R (TEG) is used as a functional measure of whole blood coagulation in pediatric cardiac surgical 1 and liver transplant patients, 2 and is a useful monitor in patients with major trauma and with coagulation deficits. To date, only one study has evaluated functional maturity of the coagulation system Journal of Clinical Anesthesia 13:20 –23, 2001 © 2001 Elsevier Science Inc. All rights reserved. 0952-8180/01/$–see front matter 655 Avenue of the Americas, New York, NY 10010 PII S0952-8180(00)00238-5