Anesth Analg 2003;97:1547
© 2003 International Anesthesia Research Society
LETTERS TO THE EDITOR
Epidural Catheterization in General Anesthesia
Peter Lierz, MD,
Anja Heinatz, MD,
Burkhard Gustorff, MD DEAA, and
Peter Felleiter, MD
Department of Anaesthesiology, Intensive Care, and Pain Medicine, Marienkrankenhaus Soest, Soest, Germany
Department of Anaesthesia and Intensive Care (B), University of Vienna, Vienna, Austria
Department of Anesthesiology and Intensive Care, Swiss Paraplegic Center, Nottwil, Switzerland
To the Editor:
Toker et al. (1) describe the case of a defective epidural catheter, through which injection of medication was impossible. However, we would like to draw attention to several points. The authors write that the catheter was inserted following induction of general anesthesia. The patient was a 56-yr-old man undergoing gastrectomy. We noticed the following: - The epidural catheter was inserted at the level of L4/5 and was advanced 4 cm into the epidural space. We believe this level is not adequate for treating peri- or postoperative pain following gastrectomy. For an epigastric surgical procedure, the catheter should have been placed at a thoracic level (2) to avoid large doses of medication.
- As described in the letter, the epidural catheter was inserted during general anesthesia. We think this fact is especially problematic because of the inability to test whether the catheter has been erroneously placed in the subdural space. Accidental nerve damage can be recognized during insertion of an epidural catheter while the patient is awake. General anesthesia precludes this, since the patient cannot say whether he or she has pain or dysesthesia. General anesthesia also precludes testing the catheter position with a probatory dose. There are multiple publications referring to this problem (3–5). Since in this case the epidural catheter was presumably placed for postoperative pain management, large amounts of local anesthetics or opioids would be necessary to attain adequate thoracic pain control. Such high doses would be problematic if the catheter has been accidentally placed in the subdural space, causing possible spinal anesthesia (following local anesthetics) or respiratory depression (following opioids). When both epidural and general anesthesia are necessary, a probatory dose of a local anesthetic should be given while the patient is still awake, prior to the first analgesic dose, in order to identify accidental subdural placement. Merely aspirating cerebrospinal fluid is not sufficient. If the patient has been under general anesthesia and medication cannot be administered epidurally, the patient may become subjected to an analgesic gap because it is necessary to wait until the patient is vigilant enough to respond verbally to the test dose. During an analgesic gap pain management is inadequate. A study in England revealed that in 60% of the 192 clinics questioned thoracic epidural catheters were placed during general anesthesia (6). Even if it is common in other countries to place a thoracic epidural catheter under general anesthesia, it is not a recommended procedure in Germany (7).
The erroneous catheter placement can often be recognized with a placement prior to induction of general anesthesia, thus preventing complications. In the case described here, it would have also been possible to identify the faulty catheter by administering a test dose before general anesthesia. Then the catheter could have been removed and a new one placed before induction.
References
- Toker K, Gürkan Y, Keser M. A faulty epidural catheter. Anesth Analg 2002; 94: 1371–2.[Free Full Text]
- Wajima Z, Shitara T, Ishikawa G, et al. Analgesia after upper abdominal surgery with extradural buprenorphine with lidocaine. Can J Anesth 1998; 45: 28–33.[Web of Science][Medline]
- Okuyama A, Saito Y, Amenomori H, et al. Subdural catheterisation uncovered by severe hypotension during epidural plus general anesthesia. Masui 1995; 44: 1373–6.[Medline]
- Bromage PR, Benumof JL. Paraplegia following intracord injection during attempted epidural anesthesia under general anesthesia. Reg Anesth Pain Med 1998; 23: 104–7.[Web of Science][Medline]
- Krane EJ, Dalens BJ, Murat Murell D. The safety of epidurals placed during general anesthesia. Reg Anesth Pain Med 1998; 23: 433–8.[Web of Science][Medline]
- Romer HC, Russell GN. A survey of the practice of thoracic epidural analgesia in the United Kingdom. Anaesthesia 1998; 53: 1016–22.[Web of Science][Medline]
- Wulf H. Epidural catheterisation in general anesthesia? Anaesthesist 1999; 48: 183–4.[Web of Science][Medline]
Response
Yavuz Gürkan, MD, and
Kamil Toker, MD
Department of Anesthesiology and Reanimation, Kocaeli University, School of Medicine, Kocaeli, Turkey
In Response:
I thank Dr. Lierz and colleagues for their valuable comments on epidural catheterization under general anesthesia. Actually, the purpose of our previous letter was to emphasize the importance of technical problems due to the epidural catheters (1).
Although placing an epidural catheter under general anesthesia is still controversial due to the possibility of unrecognized nerve injury, Grady at al. (2) have reported no new neurological deficits after placing cerebrospinal fluid drainage catheters and needles in 530 anesthetized patients. Recently, Horlocker et al. (3) have reported 4,298 thoracic surgical patients undergoing lumbar epidural catheter placement while under general anesthesia. Lumbar epidural analgesia was graded as excellent or good in 92.2% of patients with no neurologic complications due to the epidural. Gögüs et al. (4) have demonstrated that when morphine is administered from the lumbar epidural region for nephrectomy and pyelolithotomy patients, satisfactory analgesia could be provided and the radiopaque material administered in equal volumes to the analgesic could reach the thoracic segments via lumbar administration, demonstrated by computerized tomography findings. The dose of morphine required for thoracotomy is only 20% to 30% greater when morphine is administered in the lumbar than when it is administered in the thoracic epidural space (5). In the recovery room, while the test dose is administered to confirm the place of epidural catheter, the analgesic gap can be covered by IV analgesics very efficiently.
There is no randomized prospective study comparing the relative risk of placing a lumbar epidural in anesthetized and in awake patients. We think that the risk of serious neurological complications related to lumbar epidural catheterization under general anesthesia is small, yet meticulous attention to the technique and care for the patient should be provided when using epidural catheterization both in awake and anesthetized patients.
References
- Toker K, Gürkan Y, Keser M. A faulty epidural catheter. Anesth Analg 2002; 94: 1371–2.
- Grady RE, Horlocker TT, Brown RD, et al. Neurological complications after placement of cerebrospinal fluid drainage catheters and needles in anesthetized patients: implications for regional anesthesia. Anesth Analg 1999; 88: 388–92.[Abstract/Free Full Text]
- Horlocker TT, Abel MD, Messick JM, Schroeder DR. Small risk of serious neurologic complications related to lumbar epidural catheter placement in anesthetized patients. Anesth Analg 2003; 96: 1547–52.[Abstract/Free Full Text]
- Gögüs FY, Toker K, Pamir MN, et al. Computed tomography findings of the epidural spread of contrast media. Marmara Medical Journal 1990; 3: 118–21.
- Fromme GA, Steidl LJ, Danielson DR. Comparison of lumbar and thoracic epidural morphine for relief of post-thoracotomy pain. Anesth Analg 1985; 64: 454–5.[Free Full Text]
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