Background: Postoperative pain is an expected phenomenon. However, its passage beyond acceptable limits is a common and costly experience. This is particularly the case in day surgery, partly because of the increasing demand to reduce waiting lists for elective surgery, and partly because of lack of knowledge about patients' experiences of postoperative pain and relevant published research. The latter is mainly concerned with different interpretations of the phenomenon of pain that appear to have led to a variety of often inappropriate pain measurement tools.
Aim: This paper critically reviews some of the available objective and subjective measures of pain and establishes the suitability of a Visual Analogue Scale (VAS) for measuring the intensity of pain after day surgery.
Method: Nursing and health care papers published since 1983 were sought using the keywords: postoperative pain, day surgery, ambulatory surgery, rating scales, VAS, severity, assessment, tool, nursing, validity, sensitivity, reliability and their various combinations. The databases used were Medline, CINAHL, Nursing Collection, Embase, Healthstar, BMJ and several on-line Internet journals, specifically Ambulatory Surgery. The search included only papers published in the English language.
Findings: A range of interpretations of pain have led to the development of various measurement tools that address different components of pain. This inconsistency has led to ineffective pain management. Based on established criteria, the VAS was found to be methodologically sound, conceptually simple, easy to administer and unobtrusive to the respondent. On these grounds, the VAS seems to be most suitable for measuring intensity of pain after day surgery.
Conclusions: Common guidelines on the definition and measurement of pain are needed. In day surgery, the availability of a unified and reliable measure of pain that can address its sensory component, such as the VAS, will provide more reliable information about the pain experience and, hence, improve its overall management.