In 1995 Mr E, a 60-year-old antiques dealer, was admitted to a private hospital to undergo coronary artery bypass grafting to treat his troublesome ischaemic heart disease. His preoperative bloods showed a normal FBC and clotting screen. His anaesthetist, Dr R, visited him the night before the procedure.
He explained his plan to use a thoracic-epidural infusion to achieve postoperative pain control. Paralysis was not mentioned as a potential complication.
Prior to surgery, Mr E was put in the left-lateral position and an 18G Portex epidural catheter was inserted at the T12/L1 interspace using an aseptic technique. No bleeding was noted during the epidural insertion, nor was blood aspirated from the catheter.
About an hour after induction of anaesthesia, heparinisation was commenced. The surgery was documented as uneventful, with normal levels of blood loss. Heparinisation was reversed with protamine sulphate. Four units of fresh-frozen plasma and six units of platelets were given.
Mr E was admitted to ITU and was stable overnight. An epidural infusion of fentanyl and bupivacaine was given at standard dose. A note in the nursing records shows that, at 7 a.m., Mr E was moving his arms, but not his legs. Dr R saw him at 7:15 a.m. and found that Mr E was moving all his limbs, but not his feet.
This was attributed to Mr E’s drowsy state. Mr E was extubated about an hour later.
About three hours later Mr E was noted to have no movement or sensation in his legs. The epidural infusion was stopped and Dr R was telephoned. He advised the ITU staff to remove the epidural catheter and give an infusion of mannitol. Dr R attended within the hour and noted the neurological deterioration, asking for an urgent neurological opinion.
By four in the afternoon, Mr E had had an MRI scan of his spinal cord, revealing a collection of blood from T5 to T10 with cord displacement, but no compression. Four hours after this, he underwent evacuation of the blood clot via laminectomy.
Mr E did not recover motor or sensory function in his legs. A claim for damages against Dr R alleged that he had administered an epidural infusion in such a manner as to cause profuse bleeding, that he had failed to notice signs of lower-limb immobility and failed to arrange neurological assistance sufficiently quickly.
We sought opinion from two anaesthetic experts, who conducted a literature review.
Both supported the use of epidural anaesthesia for thoracotomy-related postoperative analgesia and noted benefits associated with its use. The subsequent anticoagulation, with the proviso of a normal clotting screen and platelet counts, was not felt to be a contraindication to the procedure.
One expert questioned Dr R’s withdrawal of the catheter on being informed of the paralysis, suggesting this may have worsened the haematoma and that it should have been removed during the laminectomy. This expert felt that neurological sequelae, as a potential but rare consequence of the technique, should have been discussed when gaining consent.
There was disagreement over the acceptability of the amount of time it took to bring in a neurologist and arrange neurosurgical intervention, with one expert contending that there had been an unreasonable delay which may have contributed to the permanent nature of Mr E’s disability. The most likely mechanism of injury was thought to be interference with the relatively poor thoracic cord blood supply, by the presence of the haematoma.
There were concerns over the quality of documentation of motor/sensory function in Mr E’s limbs after he arrived on ITU, with no record of their assessment on admission, or overnight. A neurosurgical expert was critical of Dr R for not assessing the lower-limb weakness more fully when he was first made aware of it. An intensive-care nursing expert criticised the absence of guidelines for managing thoracic-epidural analgesia on the unit, and the lack of documentation of assessment of neurological function, but felt that Dr R was ultimately responsible for ordering such observations.
We settled the claim, with a 20% contribution from the hospital’s insurers.
When using or introducing a relatively novel treatment or technique, it is vital to ensure that the normal clinical systems in your workplace are able to cope with its use. This may mean briefing staff, drawing up protocols and guidelines, or assessing how you may need to change your own routine practice.
The UK Royal College of Anaesthetists published some continuing medical education guidance on the use of epidural analgesia for postoperative pain relief in its July 2000 Bulletin.
A survey of the practice of thoracic-epidural analgesia discusses potential problems with its current practice in the UK and looks at pertinent consent and risk-management issues. See Romer HC and Russell GN, ‘A Survey of the Practice of Thoracic Epidural Analgesia in the United Kingdom’, Anaesthesia, 53(10):1016–22 (1998).
An illuminating case report from the same journal is relevant and worth taking into account when discussing risks of this procedure for consent purposes. See Mayall MF and Calder I, ‘Spinal Cord Injury Following an Attempted Thoracic Epidural’,Anaesthesia, 54(10):990-4 (1999).