title: In vitro effects of local anaesthetics on the thromboelastographic profile of parturients.
abstract: BACKGROUND
  Post-dural puncture headache can be an incapacitating complication of obstetric epidural analgesia/anaesthesia and early or prophylactic epidural blood patch (EBP) is one of the treatment options. Although local anaesthetic (LA) agents have been shown to have anticoagulation effects in vitro, peri-partum women are known to be hypercoagulable. We postulated that the presence of residual LA might not result in impaired haemostasis of the EBP in parturients.
  
  
  METHODS
  Blood samples from 10 healthy term parturients were subjected to thromboelastography after the addition of four different LA (lidocaine, bupivacaine, levobupivacaine, and ropivacaine) preparations.
  
  
  RESULTS
  There was a significant reduction in reaction (R) and coagulation (K) time (P<0.001, P<0.05) and an increase in alpha degrees angle (P<0.01) when comparing undiluted blood with the saline control group. Maximum amplitude (MA) and clot lysis (Ly30) did not change significantly despite the 50% dilution. The thromboelastographic parameters of all four LA-treated groups were no different from their saline controls and from each other.
  
  
  CONCLUSIONS
  At clinical dosages, LA did not cause any hypocoagulable changes on the thromboelastographic profile of healthy parturients.
authors.affiliation: Department of Anaesthesia, National University Hospital 5, Lower Kent Ridge,Singapore 119074, Singapore.
authors.forename: C
authors.initials: C
authors.lastname: Siau
authors.forename: H P
authors.initials: HP
authors.lastname: Ng
authors.forename: G M
authors.initials: GM
authors.lastname: Tan
authors.forename: B S
authors.initials: BS
authors.lastname: Ho
authors.forename: H L
authors.initials: HL
authors.lastname: Pua
mesh_terms: D000577:Amides / Q000494:pharmacology; D015360:Analgesia, Epidural / Q000009:adverse effects; D016362:Analgesia, Obstetrical / Q000009:adverse effects; D000767:Anesthesia, Epidural / Q000009:adverse effects; D000773:Anesthesia, Obstetrical / Q000009:adverse effects; D000779:Anesthetics, Local / Q000494:pharmacology*; D001777:Blood Coagulation / Q000187:drug effects*; D017217:Blood Patch, Epidural; D002045:Bupivacaine / Q000031:analogs & derivatives / Q000494:pharmacology; D005260:Female; D006261:Headache / Q000209:etiology / Q000517:prevention & control; D006801:Humans; D066298:In Vitro Techniques; D000077554:Levobupivacaine; D008012:Lidocaine / Q000494:pharmacology; D036801:Parturition / Q000097:blood*; D011247:Pregnancy; D000077212:Ropivacaine; D013916:Thrombelastography / Q000187:drug effects*
chemical_list: D000577:Amides; D000779:Anesthetics, Local; D000077212:Ropivacaine; D008012:Lidocaine; D000077554:Levobupivacaine; D002045:Bupivacaine