Effects of thoracic epidural analgesia with morphine or bupivacaine on lower oesophageal motility – an experimental study in man

Lower oesophageal peristalsis and lower oesophageal sphincter (LOS) pressure during thoracic epidural analgesia (TEA) were studied in 20 healthy volunteers. After oesophageal manometric baseline recordings, 10 volunteers received 4 mg epidural morphine. The other ten received 0.5% bupivacaine epidurally in sufficient amounts to block the sympathetic innervation of the oesophagus. Thereafter oesophageal manometry was repeated. During epidural morphine oesophageal peristalsis, resting LOS pressure and the contraction of LOS after swallowing did not change, but the relaxation of the LOS in response to swallowing decreased significantly (P < 0.01). Following TEA with bupivacaine, neither distal oesophageal peristalsis nor LOS pressure changed.