Deep dermal burn injury results in scarless wound healing in the ovine fetus

Early to mid-term fetuses heal cutaneous incisional wounds without scars; however, fetal response to burn injury has not been ascertained. We present a fetal model of thermal injury and subsequent analysis of fetal and lamb response to burn injury. A reproducible deep dermal burn injury was created in the fetus by application of water at 66 degrees C for 7 seconds, and at 82 degrees C for 10 seconds to the lamb. Macroscopically, the area of fetal scald was undetectable from day 7 post injury, while all lamb scalds were readily identified and eventually healed with scarring. Using a five-point histopathology scoring system for alteration in tissue morphology, differences were detected between control and scalded skin at all stages in lamb postburn, but no difference was detected in the fetal model after day 7. There were also large differences in content of alpha-smooth muscle actin and transforming growth factor-beta 1 between control and scalded lamb and these differences were statistically significant at day 14 (P < 0.01). This novel model of fetal and lamb response to deep dermal injury indicates that the fetus heals a deep burn injury in a scarless fashion. Further elucidation of this specific fetal process of burn injury repair may lead to improved outcome for patients with burn injury.

Measuring functional outcome in paediatric patients with burns: methodological considerations

Methodological criticisms of research undertaken in the area of paediatric burns are widespread. To date, quasi-experimental research designs have most frequently been used to examine the impact of impairments such as scarring and reduced ran e of motion on functional outcomes. Predominantly, these studies have utilised a narrow definition of functioning (e.g. school attendance) to determine a child's level of participation in activities post-burn injury. Until recently, there had been little attempt to develop and/or test a theoretical model of functional outcome with these children. Using a conceptual model of functional outcome based oil the International Classification of Functioning, Disability and Health, this review paper outlines the current state of the research literature and presents explanatory case study methodology as an alternative research design to further advance the Study of functional outcome post-burn injury. (C) 2004 Elsevier Ltd and ISBI. All rights reserved.

Temperature changes in dental pulp associated with use of power grinding equipment on equine teeth

Objective To quantify the temperature changes in the dental pulp associated with equine dental procedures using power grinding equipment. Design A matrix experimental design with replication on the same sample was followed to allow the following independent variables to be assessed: horse age (young or old), tooth type (premolar or molar), powered grinding instrument (rotating disc or die grinder), grinding time (15 or 20 seconds) and the presence or absence of water coolant. Procedure Sound premolar and molar teeth from a 6-year-old horse and a 15-year-old horse, which had been removed postmortem, were sectioned parallel to the occlusal plane to allow placement of a miniature thermocouple at the level of the dental pulp. The maximum temperature increase, the time taken to reach this maximum and the cooling time were measured (n=10 in each study). The teeth were placed in a vice and the instrument used on the tooth as per clinical situation. Results Significant differences were recorded for horse age (P < 0.001), instrument type (P < 0.001), grinding time (P < 0.001) and presence or absence of coolant (P < 0.001). There was no significant difference for tooth type. Conclusion Thermal insult to the dental pulp from the use of power instruments poses a significant risk to the tooth. This risk can be reduced or eliminated by appropriate selection of treatment time and by the use of water irrigation as a coolant. The increased dentine thickness in older horses appears to mitigate against thermal injury from frictional heat.

Sensory hypersensitivity occurs soon after whiplash injury and is associated with poor recovery

Hypersensitivity to a variety of sensory Stimuli is a feature of persistent whiplash associated disorders (WAD). However, little is known about sensory disturbances from the time Of injury until transition to either recovery or symptom persistence. Quantitative sensory testing (pressure and thermal pain thresholds, the brachial plexus provocation test), the sympathetic vasoconstrictor reflex and psychological distress (GHQ-28) were prospectively measured in 76 whiplash Subjects within 1 month of injury and then 2, 3 and 6 months post-injury. Subjects were classified at 6 months post-injury using scores on the Neck Disability Index: recovered (30). Sensory and sympathetic nervous system tests were also measured in 20 control subjects. All whiplash groups demonstrated local mechanical hyperalgesia in the cervica spine at 1 month post-injury. This hyperalgesia persisted in those with moderate/severe symptoms at 6 months but resolved by 2 months in those who had recovered or reported persistent mild symptoms. Only those with persistent moderate/severe symptoms at 6 months demonstrated generalised hypersensitivity to all sensory tests. These changes Occurred within 1 month of injury and remained Unchanged throughout the Study period. Whilst no significant group differences were evident for the sympathetic vasoconstrictor response, the moderate/severe group showed a tendency for diminished sympathetic reactivity. GHQ-28 scores of the moderate/severe group were higher than those of the other two groups. The differences in GHQ-28 did not impact on any of the sensory measures. These findings suggest that those with persistent moderate/severe symptoms at 6 months display, soon after injury, generalised hypersensitivity suggestive of changes in central pain processing mechanisms. This phenomenon did not Occur in those who recover or those with persistent mild symptoms. (C) 2003 International Association for the Study of Pain. Published by Elsevier Science B.V. All rights reserved.

Thermal injuries in three children caused by an electrical warming mattress

Peroperative hypothermia is recognized to increase mortality and morbidity, and the paediatric anaesthetist faces specific challenges resulting from the increased body surface to volume ratio, particularly in smaller children. We describe three children who were consecutive patients on one operating list and sustained severe thermal injuries. These were due to a malfunctioning electrical heating mat, despite appropriate use and monitoring by the attending anaesthetist. It is rare for thermal warming devices to cause injury. We review the use of heating mats, and suggest modifications in their manufacture which may minimize the risks associated with heating devices.

Physical and psychological factors predict outcome following whiplash injury

Predictors of outcome following whiplash injury are limited to socio-demographic and symptomatic factors, which are not readily amenable to secondary and tertiary intervention. This prospective study investigated the predictive capacity of early measures of physical and psychological impairment on pain and disability 6 months following whiplash injury. Motor function (ROM; kinaesthetic sense; activity of the superficial neck flexors (EMG) during cranio-cervical flexion), quantitative sensory testing (pressure, thermal pain thresholds, brachial plexus provocation test), sympathetic vasoconstrictor responses and psychological distress (GHQ-28, TSK, IES) were measured in 76 acute whiplash participants. The outcome measure was Neck Disability Index scores at 6 months. Stepwise regression analysis was used to predict the final NDI score. Logistic regression analyses predicted membership to one of the three groups based on final NDI scores (< 8 recovered, 10-28 mild pain and disability, > 30 moderate/severe pain and disability). Higher initial NDI score (1.007-1.12), older age (1.03-1.23), cold hyperalgesia (1.05-1.58), and acute post-traumatic stress (1.03-1.2) predicted membership to the moderate/severe group. Additional variables associated with higher NDI scores at 6 months on stepwise regression analysis were: ROM loss and diminished sympathetic reactivity. Higher initial NDI score (1.03-1.28), greater psychological distress (GHQ-28) (1.04-1.28) and decreased ROM (1.03-1.25) predicted subjects with persistent milder symptoms from those who fully recovered. These results demonstrate that both physical and psychological factors play a role in recovery or non-recovery from whiplash injury. This may assist in the development of more relevant treatment methods for acute whiplash. (c) 2004 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.

Physical and psychological factors maintain long-term predictive capacity post-whiplash injury

Higher initial levels of pain and disability, older age, cold hyperalgesia, impaired sympathetic vasoconstriction and moderate post-traumatic stress symptoms have been shown to be associated with poor outcome 6 months following whiplash injury. This study prospectively investigated the predictive capacity of these variables at a long-term follow-up. Sixty-five of an initial cohort of 76 acutely injured whiplash participants were followed to 2-3 years post-accident. Motor function (ROM; kinaesthetic sense; activity of the superficial neck flexors (EMG) during cranio-cervical flexion), quantitative sensory testing (pressure, thermal pain thresholds and brachial plexus provocation test), sympathetic vasoconstrictor responses and psychological distress (GHQ-28, TSK and IES) were measured. The outcome measure was Neck Disability Index (NDI) scores. Participants with ongoing moderate/severe symptoms at 2-3 years continued to manifest decreased ROM, increased EMG during cranio-cervical flexion, sensory hypersensitivity and elevated levels of psychological distress when compared to recovered participants and those with milder symptoms. The latter two groups showed only persistent deficits in cervical muscle recruitment patterns. Higher initial NDI scores (OR 1.00-1.1), older age (OR 1.00-1.13), cold hyperalgesia (OR 1.1-1.13) and post-traumatic stress symptoms (OR 1.03-1.2) remained significant predictors of poor outcome at long-term follow-up (r(2) = 0.56). The robustness of these physical and psychological factors suggests that their assessment in the acute stage following whiplash injury will be important. (c) 2006 International Association for the Study of Pain. Published by Elsevier B.V. All rights reserved.