The development of a multidimensional pain assessment scale for critically ill preverbal children

Abstract

Adequate pain assessment is a pre-requisite for appropriate pain management. If pain remains untreated in critically ill young children, it can have dramatic short- and long-term consequences on their health and development. Apart from humanitarian reasons, the assessment of pain has been recognised in some parts of the world as the fifth vital sign and thus should be part of standard practice of pain management. The evaluation of pain in preverbal children is, nevertheless, challenging for health professionals, as they cannot rely on self-report when making their assessment. Observational pain instruments have been developed to facilitate this task, but none of these existing instruments are appropriate for the postoperative critically ill young child. The aim of this research was to provide a clinically valid pain instrument for health professionals to use in practice for the evaluation of the pain and the effectiveness of pain treatment in critically ill young children. This thesis presents research that was conducted in three phases to (a) describe pain, (b) develop, and (c) test the pain instrument. Conceptualisation of pain and psychometric theory informed the conceptual framework for this study. An observational design was used in Phase One of the study to define pain behaviour in critically ill infants. Correlational design was used in Phase Two and Three to determine the association between the newly developed pain scale and other pain assessment instruments. Phase One of the study was conducted in the paediatric intensive care units of two tertiary referral hospitals. Eight hundred and three recorded segments were generated from recordings of five critically ill infants, aged between 0 and 9 months, who had undergone major surgery.Results indicated significant physiological and behavioural changes in response to postoperative pain and when postoperative pain was exacerbated by painful procedures. Using the pain indicators observed in Phase One, in Phase Two the Multidimensional Assessment Pain Scale (MAPS) was developed and tested for reliability and validity in 43 postoperative preverbal children from the same settings. Internal consistency and interrater reliability were moderate and good, respectively. Concurrent and convergent validity was good. In Phase Three, the MAPS' response to analgesics and clinical utility was demonstrated in a convenience sample of 19 postoperative critically ill children aged between 0 and 3 1 months of age at a tertiary referral hospital in Western Australia. Development of a pain instrument is a complex and lengthy process. This study presents the preliminary psychometric properties that support the validity and clinical utility of the Multidimensional Assessment Pain Scale. The MAPS is a promising tool for assessing postoperative pain in critically ill young children, and its clinical validity will be strengthened with further testing and evaluation.