title: Risk factors for post-tonsillectomy hemorrhage.
abstract: OBJECTIVE
  The aim of the present study was to investigate the rate of post-tonsillectomy hemorrhage (PTH) in a single institution and to evaluate the clinical risk factors for PTH.
  
  
  METHODS
  We reviewed the records of 692 patients who underwent tonsillectomy (TE) at Yokohama Minami Kyosai Hospital in Japan. PTH grades were grouped into three categories according to the severity of the hemorrhagic episode: (I) minimal hemorrhage that stopped after noninvasive treatment, (II) hemorrhage requiring treatment with local anesthesia, and (III) hemorrhage requiring reoperation under general anesthesia in the operating room. Clinical risk factors such as sex, age (adults vs. children), TE indication, surgeon's skill level, operative time, ligature type, and duration of antibiotic administration for PTH were investigated.
  
  
  RESULTS
  Among the 692 patients, 80 (11.6%) showed PTH, with primary and secondary hemorrhage accounting for 1.6% and 10.0%, respectively. A category III PTH was observed in 18 patients; thus, the overall risk of reoperation was 2.6%. The PTH episode most frequently occurred on postoperative days 5 and 6. The frequency of PTH was significantly higher in male patients and in adults (P<0.01, for both factors). Surgeon's skill was also associated with PTH rate. A stepwise multivariate logistic regression revealed that adult age (odds ratio [OR]=18.9) and male gender (OR=3.78) were the clinical risk factors for PTH. It also revealed that male gender (OR=82065335), adult age (OR=10.6), and surgeon's skill level (OR=7.50) were the clinical risk factors for the category III PTH.
  
  
  CONCLUSIONS
  The risk of PTH was higher in this report compared with previous reports, which may be associated with the definition of PTH. Clinical risk factors for PTH were adult age and male gender. The surgeon's skill level was an additional risk factor for category III PTH.
authors.affiliation: Department of Otolaryngology, Yokohama Minami Kyosai Hospital, 1-21-1 Mutsuura-higashi, Kanazawa-ku, Yokohama 236-0037, Japan. Electronic address: ikoma-r@minamikyousai.jp.
authors.forename: Ryo
authors.initials: R
authors.lastname: Ikoma
authors.affiliation: Department of Otolaryngology, Yokohama Minami Kyosai Hospital, 1-21-1 Mutsuura-higashi, Kanazawa-ku, Yokohama 236-0037, Japan.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Sakane
authors.affiliation: Department of Otolaryngology, Yokohama Minami Kyosai Hospital, 1-21-1 Mutsuura-higashi, Kanazawa-ku, Yokohama 236-0037, Japan.
authors.forename: Kazutomo
authors.initials: K
authors.lastname: Niwa
authors.affiliation: Department of Otolaryngology, Yokohama Minami Kyosai Hospital, 1-21-1 Mutsuura-higashi, Kanazawa-ku, Yokohama 236-0037, Japan.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Kanetaka
authors.affiliation: Department of Otolaryngology, Nishi-Yokohama International Hospital, 56 Gumisawa-tyo, Totsuka-ku, Yokohama 245-8560, Japan.
authors.forename: Toshiro
authors.initials: T
authors.lastname: Kawano
authors.affiliation: Department of Biology and Function in Head and Neck, Yokohama City University Graduate School of Medicine, 3-9 Fukuura, Kanazawa-ku, Yokohama, Japan.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Oridate
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002983:Clinical Competence; D005260:Female; D006801:Humans; D008297:Male; D019106:Postoperative Hemorrhage / Q000209:etiology*; D012307:Risk Factors; D014068:Tonsillectomy / Q000009:adverse effects*
keywords: Bleeding; Postoperative hemorrhage; Reoperation; Tonsillectomy