title: Safety of ultrasound-guided thoracentesis in patients with abnormal preprocedural coagulation parameters.
abstract: BACKGROUND
  Despite a low incidence of hemorrhagic complications following thoracentesis, correction or attempted correction of abnormal preprocedural coagulation parameters is still commonly performed. We aimed to assess hemorrhagic complications following ultrasound-guided thoracentesis in patients with abnormal preprocedural coagulation parameters.
  
  
  METHODS
  We analyzed 1,009 ultrasound-guided thoracenteses performed between January 2005 and September 2011 on patients with international normalized ratio (INR) &gt; 1.6, serum platelet values &lt; 50 × 109/L, or both. Procedures were divided into two groups: those in whom abnormal preprocedural coagulation parameters were not corrected before the thoracentesis (group 1) and a second group in which patients received a transfusion of platelets or fresh frozen plasma prior to thoracentesis (group 2). All procedures were evaluated for hemorrhagic complications as defined by the National Institutes of Health Common Terminology Criteria for Adverse Events.
  
  
  RESULTS
  A total of 1,009 ultrasound-guided thoracenteses were included in our study, consisting of 706 procedures in 538 patients in group 1 and 303 procedures in 235 patients in group 2. There were four hemorrhagic complications out of 1,009 procedures (0.40%; 95% CI, 0.15%-1.02%): zero in group 1 (0 of 706 or 0.0%; 95% CI, 0%-0.68%) and four in group 2 (four of 303 or 1.32%; 95% CI, 0.51%-3.36%).
  
  
  CONCLUSIONS
  Hemorrhagic complications are infrequent after ultrasound-guided thoracentesis, and attempting to correct an abnormal INR or platelet level before the procedure is unlikely to confer any benefit. We consider the procedure safe in patients with abnormal preprocedural parameters when performed by expert personnel.
authors.affiliation: Department of Medical Imaging, University of Ottawa, Ottawa, ON, Canada; Department of Radiology, Mayo Clinic School of Medicine, Rochester, MN.
authors.forename: Rebecca M
authors.initials: RM
authors.lastname: Hibbert
authors.affiliation: Department of Radiology, Mayo Clinic School of Medicine, Rochester, MN. Electronic address: atwell.thomas@mayo.edu.
authors.forename: Thomas D
authors.initials: TD
authors.lastname: Atwell
authors.affiliation: Department of Radiology, Mayo Clinic School of Medicine, Rochester, MN.
authors.forename: Alexander
authors.initials: A
authors.lastname: Lekah
authors.affiliation: Department of Radiology, Mayo Clinic, Phoenix, AZ.
authors.forename: Maitray D
authors.initials: MD
authors.lastname: Patel
authors.affiliation: Department of Health Sciences Research, Mayo Clinic School of Medicine, Rochester, MN.
authors.forename: Rickey E
authors.initials: RE
authors.lastname: Carter
authors.affiliation: Department of Radiology, Mayo Clinic School of Medicine, Rochester, MN.
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: McDonald
authors.affiliation: Department of Pulmonary and Critical Care Medicine, Mayo Clinic School of Medicine, Rochester, MN.
authors.forename: Jeffrey T
authors.initials: JT
authors.lastname: Rabatin
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001778:Blood Coagulation Disorders / Q000150:complications*; D001803:Blood Transfusion; D005260:Female; D006470:Hemorrhage / Q000453:epidemiology*; D006801:Humans; D019934:International Normalized Ratio; D008297:Male; D008875:Middle Aged; D019152:Paracentesis / Q000009:adverse effects*; D061214:Patient Safety; D010976:Platelet Count; D012189:Retrospective Studies; D018084:Ultrasonography, Interventional