[Is a biological assessment necessary to realize an obstetrical epidural anaesthesia in a patient whose interrogation and clinical examination are strictly normal?]

Abstract

In France, coagulation blood tests are usually ordered before performing an epidural anaesthesia. This French habit obeys to the fear of triggering an epidural haematoma induced by neuraxial anaesthesia. This analysis of literature shows that these practices do not protect anaesthesiologists against this clinical risk or its medico-legal consequences. As shown by epidemiological studies, epidural haematoma in pregnancy is associated to the occurrence of HELLP syndrome. On the opposite, gestational thrombocytopenia is not associated to any bleeding risk. According to the recommendations of the French Society of Anaesthesia (Sfar), only a clinical examination and an interrogatory must be done to diagnose coagulation defects before general or loco regional anaesthesia. Normal pregnancy is not an exception to this rule except for the platelet number which must be evaluated during the 3rd trimester of pregnancy. This platelet numeration might detect a rare idiopathic thrombopenic purpura. This recommendation is valid only for normal pregnancy. The clinician must ensure that pregnancy is still normal by seeking for symptoms of pregnancy-induced pathology such as preeclampsia or HELLP syndrome before setting an epidural anaesthesia. The possibly late occurrence of these complications during the per- or post-partum explain why a coagulation test performed even a few days before anaesthesia may not allow to detect any coagulation defect favouring the risk of epidural haematoma.