ABSTRACT
UNLABELLED: The impact of pain early in life is a salient issue for sickle cell disease (SCD), a genetic condition characterized by painful vaso-occlusive episodes (VOEs) that can begin in the first year of life and persist into adulthood. This study examined the effects of age and pain history (age of onset and frequency of recent VOEs) on acute procedural pain in children with SCD. Endothelin-1, a vaso-active peptide released during VOEs and acute tissue injury, and its precursor, Big Endothelin, were explored as markers of pain sensitization and vaso-occlusion. Sixty-one children with SCD (ages 2 to 18) underwent venipuncture at routine health visits. Procedural pain was assessed via child and caregiver reports and observational distress. Pain history was assessed using retrospective chart review. Three primary results were found: 1) younger age was associated with greater procedural pain across pain outcomes; 2) higher frequency of VOEs was associated with greater procedural pain based on observational distress (regardless of age); and 3) age was found to moderate the relationship between VOEs and procedural pain for child-reported pain and observational distress for children 5 years of age and older. Associations between the endothelin variables and pain prior to venipuncture were also observed. PERSPECTIVE: For children with SCD, the child's age and recent pain history should be considered in procedural pain management. The endothelin system may be involved in preprocedure pain, but additional research is needed to understand the role of endothelins in pain sensitization.
Subject(s)
Anemia, Sickle Cell/physiopathology , Endothelin-1/blood , Pain Perception/physiology , Pain/etiology , Phlebotomy/adverse effects , Adolescent , Age Factors , Anemia, Sickle Cell/complications , Anemia, Sickle Cell/psychology , Child , Child, Preschool , Female , Humans , Infant , Male , Pain/complications , Pain/psychology , Pain Management , Pain Measurement , Phlebotomy/psychology , Surveys and QuestionnairesABSTRACT
OBJECTIVE: To evaluate the psychometric properties of 4 measures of acute pain in youth with sickle cell disease (SCD) during a medical procedure. METHODS: Heart rate, child self-report, parent proxy-report, and observable pain behaviors were examined in 48 youth with SCD ages 2 to 17 years. Criterion validity for acute pain was assessed by responsiveness to a standardized painful stimulus (venipuncture) in a prospective pre-post design. Convergent validity was evaluated through the correlation across measures in reactivity to the stimulus. RESULTS: Child self-reported pain, parent proxy-report, and behavioral distress scores increased in response to venipuncture (concurrent and convergent validity). In contrast, heart rate did not reliably change in response to venipuncture. Extent of change in response to venipuncture showed moderate intercorrelation across child and parent pain ratings, and behavioral distress. Preprocedure pain ratings correlated with pain experienced during the procedure. An item analysis of observable pain behaviors suggested differences in the presentation of pain in SCD compared with previous pediatric research. CONCLUSIONS: Criterion and convergent validity were demonstrated for child-report, parent-report, and observable pain behaviors. These measures seem to tap into distinct, yet overlapping aspects of the pain experience. Assessment of acute procedural pain responses in SCD requires evaluation of preprocedural pain due to the frequent presence of low-level, baseline pain.
Subject(s)
Pain Measurement/methods , Pain Measurement/standards , Pain/diagnosis , Pain/psychology , Pediatrics , Psychometrics/methods , Adolescent , Anemia, Sickle Cell/complications , Child , Child, Preschool , Female , Heart Rate/physiology , Humans , Male , Pain/etiology , Phlebotomy/methods , Reproducibility of Results , Surveys and QuestionnairesABSTRACT
UNLABELLED: Endothelin-1 (ET-1) is a chemical mediator released by the body at sites of injury and disease. This study tests the hypothesis that ET-1-induced nociception changes with age and sex. Intraplantar ET-1 (1.1 and 3.3 nmol) produced age-specific paw flinching and licking (postnatal day 7 > 21 > 60). The onset and duration of the nociceptive responses was dependent on age. Postnatal day (P) 21 and 60 rats displayed an immediate onset of behavior that subsided with time, whereas the P7 rats had a delayed behavioral response that onset at 20 minutes after ET-1 administration and continued beyond the 75 minute observation period. P7 males showed greater paw flinching compared with females. In addition to spontaneous nociceptive behaviors, ET-1 produced mechanical allodynia in all ages. As with spontaneous nociception, ET-1-induced mechanical allodynia was of a longer duration in the younger aged rats compared with adult rats. These findings show that ET-1 produces both spontaneous nociceptive behaviors and evoked mechanical allodynia in both young and adult rats but that the temporal profile and the size of the responses are age- and sex-dependent. These findings are the first description of age- and sex-specific ET-1-induced nociception. PERSPECTIVE: Endothelin-1 is a vasoactive peptide released into the systemic circulation after stress and cold pain as well as locally in tissue after injury and disease. These findings suggest greater pain to stimuli that release endogenous endothelin in younger versus older organisms. This developmental approach to studying ET-1-induced pain further illustrates the need for understanding pain mechanisms as a function of the development of the organism so as to better treat pain across the life span.
