Prolongation of the prothrombin time and activated partial thromboplastin time in children with sickle cell disease.
BACKGROUND
Patients with sickle cell disease (SCD) have high rates of perioperative complications, including bleeding 1,2.


METHODS
We conducted a retrospective review of pre-operative coagulation studies in pediatric patients with SCD followed by a prospective study of 100 well children with SCD to determine the prevalence of abnormal coagulation screening tests, and to evaluate potential etiologies.


RESULTS
In the retrospective study, 32/84 (38.1%) had a prolonged prothrombin time (PT), compared to 8/100 in the prospective study. Prolongations of the activated partial thromboplastin time (aPTT) were less common. Children in the prospective study with prolonged PTs had significantly lower levels of Factor V and VII compared to those with normal PTs. Factor VII levels were <50% in 4/8 with long PTs, compared to 3/92 with normal PTs, P=0.001. Though retrospectively, several patients had normalization of their PT with vitamin K, there was no laboratory evidence of vitamin K deficiency in the prospective study. In the retrospective analysis, six of seven children who had pre-operative coagulation studies and significant intraoperative blood loss had prolonged PTs (P=0.04).


CONCLUSIONS
Children with SCD admitted for surgical procedures were more likely to have prolonged PTs than those tested at a well visit. There was intra-patient variability in coagulation studies that may be related to clinical status, hepatocellular dysfunction, and/or increased clotting factor consumption. Future well-designed prospective studies to determine whether abnormal coagulation studies are associated with an increased risk of perioperative bleeding in children with SCD are necessary.
Raffini
Leslie J
LJ
Division of Hematology, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania 19104-4399, and Duke University School of Medicine, Durham, NC, USA. raffini@email.chop.edu
Niebanck
Alison E
AE
Hrusovsky
Joanne
J
Stevens
Amanda
A
Blackwood-Chirchir
Anne
A
Ohene-Frempong
Kwaku
K
Kwiatkowski
Janet L
JL
D000293:Adolescent; D000328:Adult; D000755:Anemia, Sickle Cell / Q000097:blood* / Q000150:complications; D001778:Blood Coagulation Disorders / Q000150:complications / Q000175:diagnosis*; D002648:Child; D002675:Child, Preschool; D019992:Databases as Topic; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D010314:Partial Thromboplastin Time; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011517:Prothrombin Time; D012189:Retrospective Studies; D013997:Time Factors