Year : 2009  |  Volume : 12  |  Issue : 2  |  Page : 166--167

High thoracic epidural analgesia for cardiac surgery: Time to move from morbidity to quality of recovery indicators


Colin F Royse 
 Anaesthesia and Pain Management Unit, Department of Pharmacology, University of Melbourne; and Cardiothoracic Anaesthetist, The Royal Melbourne Hospital, Australia

Correspondence Address:
Colin F Royse
Level 8, Medical Building, University of Melbourne, Carlton, Victoria, 3010
Australia




How to cite this article:
Royse CF. High thoracic epidural analgesia for cardiac surgery: Time to move from morbidity to quality of recovery indicators.Ann Card Anaesth 2009;12:166-167


How to cite this URL:
Royse CF. High thoracic epidural analgesia for cardiac surgery: Time to move from morbidity to quality of recovery indicators. Ann Card Anaesth [serial online] 2009 [cited 2020 Sep 30 ];12:166-167
Available from: http://www.annals.in/text.asp?2009/12/2/166/53429


Full Text

The Editor,

I am yet again disappointed by the intensely negative and one-sided opinion delivered by Dr. Mark Chaney on the subject of thoracic epidural anesthesia in cardiac surgery. [1] There are a number of issues that I believe should be challenged in his editorial. For those practitioners, who actually perform epidurals, the most important reason for inserting them is to improve the quality of postoperative analgesia. We do not insert epidurals to save lives! There are numerous studies published that attest to the improved analgesia associated with high thoracic epidural analgesia (HTEA), and very few that do not show a difference. None of the studies to date have been adequately powered to examine morbidity or mortality indicators in cardiac surgery. It is well-known that to affect a 50% change in outcome in cardiac surgery would require a study of several thousand patients. It is therefore incorrect to assume that a difference does not exist simply because the studies performed have not been powered sufficiently to address those questions. He also demonstrates a blinkered viewpoint of what constitutes outcome, citing in most instances morbid complications such as neurological dysfunction, or renal dysfunction, and so forth. He consistently fails to address quality indicators of the recovery, which are arguably more in keeping with the nature of the intervention (HTEA). As an example, if Dr. Chaney had actually read my paper, [2] he may have identified that patients receiving HTEA were three times less likely to suffer symptoms of depression or posttraumatic stress disorder; and the effect on depression was long lasting. [3] This is an example of a quality recovery indicator rather than the conventional "cardiac morbidity" indicators. I would argue that the paper by Hansidottir [4] is not "the best designed study to date," as he suggests. Firstly, patient controlled epidural analgesia (in this author's opinion), is not the best way to use an epidural. The idea is to maintain a block for the duration of analgesia, rather than to allow the block to constantly recede. If the trigger for the patient to administer more analgesia is pain; then this study automatically biases the patient towards suffering the pain. Secondly, those who have extensive experience with this technique might argue that these blocks rarely fail; I would argue that a 17% failure rate for HTEA is very high. This must bring into question the conduct of study, and therefore the conclusion that can be derived from it.

What about safety? The latest risk analysis published [5] indicates a risk of epidural hematoma of 1:12000 for cardiac surgery. This makes it no more dangerous (though no less dangerous), than epidural use for other types of surgery. In the context of cardiac surgery, this is a very remote risk, though it will surely happen somewhere in the world. The risk to the individual patient is very low. What is missing from Dr. Chaney's editorial is, a sense of balance. He fails to mention the potential risk of other analgesia therapies, and there is an underlying impression that anything else is "risk-free". I doubt that any proponents of epidural used may argue that there is no risk of disaster, but it is wrong to assume that disasters do not happen with alternative analgesia strategies. It is also wrong to be overly emotive on the issue of hematoma. If it happens, it is a terrible complication, but so too is renal failure requiring dialysis, or hypoxic brain damage following respiratory arrest; and no less a disaster to the patient than paralysis.

So, do we need to justify using an epidural for anything other than good postoperative pain relief, or improving quality of recovery? This question has recently been addressed by Wijeysundera and colleagues, [6] who performed a propensity scored analysis of mortality in patients receiving postoperative epidural analgesia for noncardiac surgery. They raise a point that a powerful study to detect a small (0.2% absolute reduction) mortality risk reduction in high risk patients would require, a study of 55,000 patients in each group. They found a small reduction in mortality in the patients receiving epidural analgesia (number needed to save one life was 477). The incidence of spinal hematoma was rare (0.02%), and was not significantly different between those receiving epidurals or not. The authors point out that their study should not be used as evidence that epidurals will save lives, as the effect size was small and the numbers required were large. However, the implication is that for every patient damaged with an epidural, perhaps nine lives can be saved. The fear that epidurals are inherently more dangerous than conventional treatments has not been substantiated in this large cohort study. Even in cardiac surgery, the fear that systemic anticoagulation will increase, the risk of hematoma has not been borne out over the last 20 years. In an accompanying editorial by Barrington and Scott, [7] the issue of lives saved to patients damaged lead them to conclude that, "in many cases, pain relief alone is an unambiguous clinical indication for postoperative epidural analgesia".

The continued debate on epidurals for cardiac and noncardiac surgery needs to progress from surgical morbidity indicators to quality of recovery outcomes.

References

1Chaney MA. Thoracic epidural anaesthesia in cardiac surgery--the current standing. Ann Card Anaesth 2009;12:1-3.
2Royse C, Royse A, Soeding P, Blake D, Pang J. Prospective randomized trial of high thoracic epidural analgesia for coronary artery bypass surgery. Ann Thorac Surg 2003;75:93-100.
3Royse C, Remedios C, Royse A. High thoracic epidural analgesia reduces the risk of long-term depression in patients undergoing coronary artery bypass surgery. Ann Thorac Cardiovasc Surg 2007;13:32-5.
4Hansdottir V, Philip J, Olsen MF, Eduard C, Houltz E, Ricksten SE. Thoracic epidural versus intravenous patient-controlled analgesia after cardiac surgery: a randomized controlled trial on length of hospital stay and patient-perceived quality of recovery. Anesthesiology 2006;104:142-51.
5Bracco D, Hemmerling T. Epidural analgesia in cardiac surgery: an updated risk assessment. Heart Surg Forum 2007;10:E334-7.
6Wijeysundera DN, Beattie WS, Austin PC, Hux JE, Laupacis A. Epidural anaesthesia and survival after intermediate-to-high risk noncardiac surgery: a population-based cohort study. Lancet 2008;372:562-9.
7Barrington MJ, Scott DA. Do we need to justify epidural analgesia beyond pain relief? Lancet 2008;372:514-6.