Fluctuations in established infant pain behaviors.

This study compares behaviors that differed across levels of established (e.g., nonprocedural) infant pain with those that differed between periods of greater and lesser distress within any level of infant pain. Sixty-four videotaped infants of two ages (0 to 3 months and 7 to 12 months) and four levels of established infant pain (none, mild, moderate, and severe) were used. Pain was from medical or surgical causes. Behaviors were compared between the most distressed (HI) and the least distressed (LO) video segments per infant and across the four levels of infant pain using a two-level (distress and level of pain) MANOVA. Many behaviors were indicative of high levels of established pain and greater distress. Others increased with greater distress but lower levels of pain. Findings suggest that many behaviors indicative of high distress that constitute the immediate infant pain response are not good indicators of levels of established infant pain.