Obesity, pain, and sedation are importantBMJ 1996; 312 doi: https://doi.org/10.1136/bmj.312.7039.1159 (Published 04 May 1996) Cite this as: BMJ 1996;312:1159
- Andrew Higgs
- Registrar in anaesthesia Department of Anaesthesia and Intensive Care, Royal Liverpool University Hospital, Liverpool L7 8XP
EDITOR,—John C Hall and colleagues stratify their patients as high risk only on the basis of American Society of Anesthesia grade (>1) and advanced age (>60 years) and then imply that other putative risk factors are similar in the two (high and low risk) groups. They seem to ignore one major risk factor for the development of postoperative respiratory complication—namely, obesity. Although the two groups are apparently well matched with respect to most criteria of comorbidity, no mention is made of the two groups' body mass indices. If populations are not weight matched it is impossible to make a valid comparison.2
In addition, Hall and colleagues' treatment of the role of postoperative analgesia in the development of pulmonary sequelae is superficial. Simply to classify the mode of pain relief as epidural or narcotic dosage is inadequate: what is more important is the quality of the analgesia delivered.3 In the context of postoperative pain relief, the narcotic dosage alone is a meaningless concept.4 Visual analogue scores are the optimal technique for assessing pain and can readily be used at the bedside. The quality of analgesia is of the utmost importance in this study. If patients' pain was inadequately relieved it is difficult to see how they could comply fully with physiotherapy, deep breathing, or incentive spirometry.
Similarly, although the authors refer to the importance of postoperative somnolence in the development of basal atelectasis and subsequent infection, this does not seem to have been assessed. This is a pity, since simple and reliable sedation scoring systems are available. It is of concern that sedation was not recorded in patients receiving epidural or narcotic infusions.5
In conclusion, we do not know whether the methods of prophylaxis against respiratory complications are equivalent. The results may be similar because one group was too fat, too sedated, or in too much pain to breathe deeply or comply with physiotherapy and so clear the secretions whose retention predisposes to chest infection.
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