POSTOPERATIVE PAIN ASSESSMENT NEWBORNS

POSTOPERATIVE PAIN ASSESSMENT IN NEONATES
One factor that has contributed to inadequate pain management in neonates has been the pervasive belief that neonates do not feel pain. This misconception has been perpetuated, at least in part, by the conspicuous absence of adequate tools to assess pain levels in this patient population. To a large extent, pain assessment in older patients relies upon the patient's ability to report pain level in some form to the caregiver. When patients cannot express pain verbally, pain assessment depends more on evaluations by the caregiver. Even when pain is evident, quantifying the pain level is not easy.

An effective pain assessment tool must be able to objectively quantify the pain level of the patient so that the healthcare provider can accurately measure the effectiveness of interventions designed to alleviate unnecessary suffering. Although no perfect tool exists yet for assessing pain in neonates, infants, and preverbal children, several very useful tools are available.


The Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) was one of the first observational pain scales. This tool includes the categories of (1) cry, (2) facial expression, (3) verbal response, (4) torso position, (5) leg activity, and (6) arm movement in relationship to the surgical wound. In general, each category is scored 0, 1, 2, or 3, with higher scores indicating higher pain levels, but the scale varies with each category evaluated. Originally, CHEOPS was used to evaluate postoperative pain in children aged 1-7 years. Evaluators determined that it was both valid and reliable for assessing pain in this patient group. Admittedly, a pain assessment tool that is appropriate for other preverbal children may not be appropriate for neonates. However, the development of CHEOPS has provided a tool against which the validity of other pediatric pain assessment tools can be measured.

The Objective Pain Scale (OPS), developed by Broadman and Hannallah, has demonstrated both validity and reliability in pain assessment. OPS assesses (1) blood pressure, (2) crying, (3) movement, (4) agitation, (5) posture, and (6) verbalization. Each parameter is scored 0, 1, or 2, with higher scores indicating greater distress. This instrument is important because it includes a cardiovascular parameter in the assessment of postoperative pain. Many advocate use of cardiovascular parameters as the most objective means of measuring the pain response in preverbal children. However, the utility of cardiovascular parameters is limited because other causes of distress may also cause dramatic changes in these parameters.

Cardiovascular parameters, while not sufficient as the sole means of assessing pain in this patient population, may be helpful. Unfortunately, OPS, like CHEOPS, has been used largely for infants and children, not neonates.

The COMFORT scale has been favorably received as a tool to assess postoperative pain in the neonatal population. This tool was originally developed to assess distress in ventilated patients in the pediatric ICU. However, the COMFORT scale demonstrated reliability and validity for assessing pain in postoperative patients in one large study that evaluated pain in 158 neonates along with older infants and children.

This scale is composed of 6 behavioral items, (1) alertness, (2) calmness, (3) muscle tone, (4) movement, (5) facial tension, and (6) respiratory response, and 2 physiologic items, (1) heart rate and (2) mean arterial blood pressure. Each item may be scored 1, 2, 3, 4, or 5, with a higher score indicating a greater level of distress. The greater number of variables assessed and the increased number of scores possible for each variable may enable this tool to identify more subtle changes in patient discomfort. On the other hand, greater complexity may be a disadvantage in terms of the clinical utility of this scale. A fourth scale, CRIES, may also be useful to assess the pain of neonates postoperatively. This scale analyzes 5 variables, (1) crying, (2) requirement of increased oxygen administration, (3) increased vital signs, (4) expression, and (5) sleeplessness. Each variable is scored 0, 1, or 2. This instrument has demonstrated validity, reliability, user friendliness, and acceptance as a postoperative pain assessment tool among neonatal intensive care nurses.

Each of the pain assessment instruments discussed has strengths and limitations. For optimal use of any pain assessment tool, the physicians and neonatal nursing staff of a given hospital should select a tool, familiarize staff with its use, and systematically integrate its use into the institution's policies. This maintains the validity and reliability of the tool in measuring pain in neonates and allows appropriate intervention to be undertaken, thereby minimizing unnecessary suffering in the postoperative neonatal patient.