International journal of obstetric anesthesia
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Int J Obstet Anesth · Jan 1999
Transfer of lidocaine across the dual perfused human placental cotyledon.
Factors affecting lidocaine transfer across the normal term human placenta were studied using the dual perfused isolated single cotyledon. Experiments were performed using perfusates which provided equal protein binding in both the maternal and fetal circuits as well as perfusates that approached the actual in vivo maternal/fetal protein binding gradient. Additional experiments were performed to investigate the effects of increasing maternal lidocaine concentration (5, 10, 40, 80 microg/mL) on maternal to fetal (M-->F) lidocaine transfer across the human placenta. ⋯ When protein binding was similar in the two circuits, M-->F transfer ratios (lidocaine transfer/antipyrine transfer) were significantly lower than the transfer ratios seen in the F-->M direction (0.59+/-0.04 versus 0.84+/-0.06, P<0.05). Transfer ratios (M-->F: 0.83+/-0.06, F-->M: 0.96+/-0.06) were not reduced when the physiological maternal/fetal protein binding gradient was present. Lidocaine transfer was not diminished by increasing maternal concentrations and, in contrast to bupivacaine, was not significantly affected by its binding.
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Int J Obstet Anesth · Jan 1999
An audit of single dose epidural diamorphine during elective caesarean section at a district general hospital.
Mothers receiving combined spinal-epidural (CSE) anaesthesia for elective caesarean section (n = 188) were audited. A single dose of epidural diamorphine (2-3 mg) was given during surgery. Unless contraindicated, diclofenac 100 mg was given per rectum at the end of surgery. ⋯ Nausea was uncommon: mild (19%), moderate (10%), severe (2%); 16% of mothers received anti-emetics. Itching was less than previous reports with subarachnoid diamorphine. Single dose epidural diamorphine can be used during elective caesarean section rendering systemic opiates unnecessary.