title: Risk factors affecting hemorrhage after tooth extraction in patients undergoing continuous infusion with unfractionated heparin.
abstract: OBJECTIVE
  To identify the risk factors affecting the incidence of postoperative hemorrhage (POH) associated with tooth extraction in patients undergoing continuous infusion with unfractionated heparin.
  
  
  METHODS
  In the present retrospective study, the medical records of patients who had undergone tooth extraction during continuous infusion of unfractionated heparin were reviewed. The primary predictor variables were demographics (age, gender), heparin dose and degree of anticoagulant effect (activated partial thromboplastin time [APTT]), total number of extracted teeth and number of extracted teeth per occasion, and type of tooth extraction (simple extraction or surgical extraction). The primary outcome variable was the incidence of POH. The incidence of POH in each APTT category was also evaluated. The Mann-Whitney U test, χ(2) test, or Fisher exact test were used for comparison between the non-POH and POH groups and the incidence of POH stratified by the categorized APTT values. Logistic regression analysis was then used to detect the factors affecting POH. The level of statistical significance was P < .05.
  
  
  RESULTS
  Tooth extraction was performed on 35 occasions in 31 patients. POH occurred 10 times (28.6%). The comparison of the POH group (10 occasions) and non-POH group (25 occasions) showed that the median APTT value in the POH group (62 seconds) was significantly prolonged compared with that in the non-POH group (42 seconds). The incidence of POH was significantly greater in the group with an APTT of 57 seconds or greater. Logistic regression analysis revealed that the APTT was the only factor related to the occurrence of POH.
  
  
  CONCLUSIONS
  The results of the present study suggest that POH in tooth extraction occurs often in patients with an APTT of 57 seconds or greater when the continuous heparin infusion cannot be stopped.
authors.affiliation: Department of Dental Anesthesiology, Osaka University Graduate School of Dentistry, Osaka, Japan. ysn-mori@dent.osaka-u.ac.jp
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Morimoto
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Niwa
authors.forename: Kazuo
authors.initials: K
authors.lastname: Minematsu
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000008:administration & dosage / Q000009:adverse effects*; D005260:Female; D006493:Heparin / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D007262:Infusions, Intravenous; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D006472:Oral Hemorrhage / Q000517:prevention & control*; D010314:Partial Thromboplastin Time; D019106:Postoperative Hemorrhage / Q000517:prevention & control; D012307:Risk Factors; D018709:Statistics, Nonparametric; D014081:Tooth Extraction / Q000009:adverse effects*
chemical_list: D000925:Anticoagulants; D006493:Heparin