Dear Editor,

The title of the paper by Sousa et al. [1] on the use of patient-controlled analgesia is misleading, since the majority of the patients in the study appeared to be suffering from uncontrolled background pain rather than “breakthrough pain” [2]. The authors define breakthrough pain as a “transient exacerbation of pain despite the use of around-the-clock analgesia,” and reference the review article by Haugen et al. [3]. However, Haugen et al. concluded that “it is certainly questionable to characterize and treat breakthrough pain (BTP) when baseline pain is not controlled.”

Breakthrough pain is a distinct entity, although the clinical features vary from individual to individual (and can vary within an individual at the same time) [4]. The term should not be used to describe any exacerbation of pain, but restricted to exacerbations of pain that occur in patients with “stable and adequately controlled pain” [2, 3]. The management of breakthrough should be individualized, with the use of rescue medication (including patient-controlled analgesia) being one of many potential therapeutic options [2]. Other therapeutic options include treatment of the underlying cause of the pain, avoidance/treatment of the precipitating factors of the pain, modification of the background analgesic regimen (“around the clock medication”), use of nonpharmacological methods, and use of interventional techniques.

Yours sincerely,

Dr Andrew Davies