Effect of cooling and re-warming on cerebral and whole body electrical impedance

Cerebral electrical impedance is useful for the detection of cerebral edema following hypoxia in newborn infants. Thus it may be useful for determining neurological outcome or monitoring treatment. Hypothermia is a promising new therapy currently undergoing trials, but will alter impedance measurements. This study aimed to define the relationship between temperature and both cerebral and whole body electrical impedance, and to derive correction factors for adjustment of impedance measurements during hypothermia. In eight anaesthetized 1-2 day old piglets rectal, tympanic and scalp temperatures were monitored continuously. Following baseline readings at a rectal temperature of 39degreesC, piglets were cooled to 32degreesC. Four piglets were re-warmed. Cerebral and whole body impedance were measured at each 0.5degreesC as rectal temperature decreased. There was a strong linear relationship between both cerebral and whole body impedance and each of the temperatures measured. There was no difference in the relationship between impedance and rectal, tympanic or scalp temperatures. The relationship for impedance and rectal temperature was the same during cooling and re-warming. Using the correction factors derived it will be possible to accurately monitor cerebral and whole body fluid distribution during hypothermic treatment.

Loss of glial glutamate transporters and induction of neuronal expression of GLT-1B in the hypoxic neonatal pig brain

The homeostasis of glutamate is critical to normal brain function; deficiencies in the regulation of extracellular glutamate are thought to be a major determinant of damage in hypoxic brains. Extracellular levels of glutamate are regulated mainly by plasmalemmal glutamate transporters. We have evaluated the distribution of the glutamate transporter GLAST and two splice variants of GLT-1 in the hypoxic neonatal pig brain using this as model of neonatal humans. In response to severe hypoxic insults, we observe a rapid loss of two glial glutamate transporters from specific brain regions, such as the CA1 region of the hippocampus, but not the dentate gyrus. The spatial distribution of loss accords with patterns of damage in these brains. Conversely, we demonstrate that hypoxia evokes the expression of a splice variant of GLT-1 in neurons. We suggest that this expression may be induced in response to elevated extracellular glutamate around these neurons, and that this splice variant may represent a useful marker for direct quantification of the extent of likely neuronal damage in hypoxic brains. © 2004 Elsevier B.V. All rights reserved.

Treatment of partial-thickness burns: A prospective, randomized trial using Transcyte (TM)

Background: The purpose of the present study was to compare the effectiveness of three burns dressings (TransCyte, a bio-engineered skin substitute; Biobrane; and Silvazine cream (silver sulphadiazine and 0.2% chlorhexidine)), in treating children with partial-thickness burns. The primary objective was to determine the days until greater than or equal to90% re-epithelialization. The secondary objectives were to evaluate the number of wounds requiring autografting and the number of dressing changes/local wound care required. Methods: Study wounds were identified on each patient and the patients were randomized to receive TransCyte or Biobrane or Silvazine. Assessment of study wound closure began at 2 days after treatment and continued at least every other day thereafter until the wounds re-epithelialized or were autografted. A laser Doppler imaging system was used as an adjunct to assessing the depth of the burn. Results: Thirty-three patients with 58 wound sites enrolled in the study (TransCyte, n = 20, Biobrane, n = 17; Silvazine, n = 21). Mean time to re-epithelialization was 7.5 days for TransCyte, 9.5 days for Biobrane, and 11.2 days for Silvazine. The number of wounds requiring autografting were 5/21 (24%) for Silvazine, 3/17 (17%) for Biobrane, and 1/20 (5%) for TransCyte. Conclusions: When used in partial-thickness burns in children, TransCyte promotes fastest re-epithelialization and required less overall dressings then Biobrane or Silvazine. Patients who received Silvazine or Biobrane require more autografting than those treated with TransCyte.

Hot beverage scalds in Australian children

Our objective was to compile data on the mechanism and severity of injuries associated with hot beverage burns in children. We identified 152 children over a 3-year period who attended a tertiary level burns center, representing 18% of all children treated. Their median age was 17.5 months and median body surface area burned was 4% (range, 0.25% to 32%). Significantly, 52% of children required admission, 18% received a split skin graft, and 26% required long-term scar management. In 70% of all cases, the mechanism of injury was the child pulling the hot beverage over himself or herself. In 80% of incidents, a primary care giver witnessed the injury. These findings indicate that scalding from hot beverages carries significant morbidity and is an important pediatric public health issue. It is clear that further research towards effective education programs for primary caregivers is warranted.

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.

Snoring and its association with asthma in Indigenous children living in the Torres Strait and Northern Peninsula Area

Objective: Respiratory health of Indigenous and minority ethnic groups in affluent countries is poorer than their non-minority counterparts and sleep disorders are no exception. In children, obstructive sleep apnoea has the potential to result in serious long-term consequences. In 1999, we studied 1650 children and adolescents living in the Torres Strait and the Northern Peninsula Area, Australia. Here we report prevalence of snoring in these communities and relate its association with asthma symptoms. Methods: A population-based cross-sectional study was conducted in the Torres Strait region. Five indigenous communities were randomly selected and information was collected using a structured face-to-face interview based on a standardized questionnaire. There was a 98% response rate, and 1650 children, 0-17 years of age, were included in the study. Results: Overall, the prevalence of snoring was 14.2% (95% CI 12.5-15.9); 3.6% (95% CI 2.7-4.6) reported snorting, and 6% (95% CI 4.9-7.2) reported restless sleep. The prevalence of snoring was significantly higher among males (17.1% for males and 10.8 for females, P = 0.005). Children were five times more likely to have experienced snoring and snorting if they reported wheezing in the last 12 months. Conclusion: We conclude that the prevalence of symptoms suggestive of obstructive sleep problems is relatively high in children of this region. This highlights the need for awareness among the community patients and physicians about the problem of obstructive sleep-disordered breathing, especially in children with asthma, and for the need for further studies to measure prevalence of sleep breathing disorders among Indigenous Australians.

Hospital-based case-control study of bronchiectasis in indigenous children in central Australia

Background: Childhood pneumonia has been reported to be associated with the development of bronchiectasis but there are no case-control studies that have examined this. This study examined the relationship between hospital admission for episode(s) of pneumonia and the risk of radiologically proven bronchiectasis. Methods: A medical record-based case-control study of bronchiectasis in Indigenous children was conducted in Central Australia. Controls (183), matched to cases (61) by gender, age and year of diagnosis, were Indigenous children hospitalized with other conditions. Results: There was a strong association between a history of hospitalized pneumonia and bronchiectasis [odds ratio (OR), 15.2; 95% confidence interval (95% CI) 4.4-52.7]. This was particularly evident in recurrent hospitalized pneumonia (P for trend < 0.01), severe pneumonia episodes with longer hospital stay (P for trend < 0.01), presence of atelectasis (OR 11.9; 95% CI 3.1-45.9) and requirement for oxygen (P for trend < 0.01). The overall number of pneumonia episodes, rather than its site, was associated with bronchiectasis. Although the total number of pneumonia episodes in the first year of life did not increase the risk of bronchiectasis, more severe episodes early in life did. Malnutrition, premature birth and being small for gestational age were more common findings among cases. Breast-feeding appeared to be a protective factor (OR 0.2; 95% CI 0.1-0.7). Conclusions: Although we cannot fully answer the question of why bronchiectasis is much more common in Indigenous children, we have provided strong evidence of an association between bronchiectasis and severe and recurrent pneumonia episodes in infancy and childhood.

Effect of inspiratory flow on methacholine challenge in children

Regulation of inspiratory flow alters the outcomes of the methacholine (MHC) challenge in adults and cough receptor sensitivity in children. The effect of inspiratory flow on the reproducibility of the MHC challenge in children is unknown. The aim of this study was to evaluate the effect of inspiratory flow alteration on the repeatabilty of the MHC challenge in children with and without asthma. Twenty-five children undertook the MHC challenge on three different days by using a dosimeter connected to a setup that allowed regulation of inspiratory flow and pattern. Children were randomized to commence the challenges at 20 or 60 L/min, and the last challenge was performed at 20 L/min. The within-subject standard deviation, 95% range for change, and doubling dose for the differing inspiratory flow (20 vs. 60 L/min) was more than twice that of when inspiratory flow was maintained at 20 L/min for both occasions. The range of the limits of agreement of the Bland and Altman plot was smaller when inspiratory flow was constant. For short-term comparative individual studies in children, inspiratory flow should be regulated. Laboratories and research measuring change in airway hyperrepsonsiveness to MHC should determine and report reproducibility indices of the challenge so airway hyperresponsiveness changes can be interpreted meaningfully.

Endoscopic intratracheal carbon dioxide measurements during pediatric flexible bronchoscopy

Background: CO2 monitoring is recommended for thoracic telescopic procedures and for spontaneous breathing general anesthesia in children. During flexible bronchoscopy (FB) in children, the various currently available methods of CO2 measurements are limited. The CO2 falls and increases have been reported in FB but it is unknown whether airway lesions predispose to CO2 change. The aim of this study was to describe and validate endoscopic intratracheal CO2 measurements in children undergoing FB under spontaneously breathing GA. Methods: Endtidal CO2 (PECO2) measurements at the start (Start-CO2) and end (End-CO2) of FB on 100 consecutive children were performed using a newly designed endoscopic intratracheal method. To validate the method blood gas sampling was simultaneously performed in 28 children and results analyzed using the Bland and Altman method, intraclass correlation and 95% range for repeatability. Results: End-CO2 and CO2-change (End-CO2 minus Start-CO2) were significantly different in children with airway lesions (CO2 change: no lesion = 3 mmHg, extrathoracic airway lesion = 4.5, intrathoracic airway lesion = 8, P = 0.038). There was no significant difference in Start-CO2 values among the groups. CO2-change in those aged > 12 months was similar to those >12 months. Intratracheal CO2 measurements were comparable with arterial blood values in the Bland and Altman plots. The intraclass correlation was 0.69 and 95% range for repeatability was 3.7-4.17 mmHg. Conclusions: Midtracheal PECO2 provides a useful estimate of PaCO2 for monitoring the respiratory status of children undergoing FB. The presence of airway lesions rather than age is associated with significant increased PCO2 rise.

Expression of SHOX in human fetal and childhood growth plate

Abnormalities in the growth plate may lead to short stature and skeletal deformity including Leri Weil syndrome, which has been shown to result from deletions or mutations in the SHOX gene, a homeobox gene located at the pseudoautosomal region of the X and Y chromosome. We studied the expression of SHOX protein, by immunohistochemistry, in human fetal and childhood growth plates and mRNA by in situ hybridization in childhood normal and Leri Weil growth plate. SHOX protein was found in reserve, proliferative, and hypertrophic zones of fetal growth plate from 12 wk to term and childhood control and Leri Weil growth plates. The pattern of immunostaining in the proliferative zone of childhood growth plate was patchy, with more intense uniform immunostaining in the hypertrophic zone. In situ hybridization studies of childhood growth plate demonstrated SHOX mRNA expression throughout the growth plate. No difference in the pattern of SHOX protein or mRNA expression was seen between the control and Leri Weil growth plate. These findings suggest that SHOX plays a role in chondrocyte function in the growth plate.

A feasibility study of email communication between the patient's family and the specialist burns team

We investigated whether the parents of burns patients could capture suitable clinical images with a digital camera and add the necessary text information to enable the paediatric burns team to provide follow-up care via email. Four families were involved in the study, each of whom sent regular email consultations for six months. The results were very encouraging. The burns team felt confident that the clinical information in 30 of the 32 email messages (94%) they received was accurate, although in I I of these 30 cases (37%) they stated that there was room for improvement (the quality was nonetheless adequate for clinical decision making). The study also showed that low-resolution images (average size 37 kByte) were satisfactory for diagnosis. Families were able to participate in the service without intensive training and support. The user survey showed that all four families found it easy and convenient to take the digital photographs and to participate in the study. The results suggest that the technique has potential as a low-cost telemedicine service in burns follow-up, and that it requires only modest investment in equipment, training and support.

Dr James George Beaney (1828-1891): A pioneer Australian paediatrician and paediatric surgeon

Dr James George Beaney (1828-1891) was a flamboyant and controversial Melbourne surgeon and paediatrician. He was the first in Australia, in 1859, to publish a medical textbook; and the first, in 1873, to publish a paediatric text, Children: their treatment in health and disease. An analysis of four of his published works relating to paediatrics and paediatric surgery establishes his place as a true pioneer in the chronology of children's medicine and welfare in his adopted land. He undertook heroic yet conservative surgery on children, was the first to write in detail about paediatric anaesthesia, and was the pioneer of family planning in Australia. In Children: their treatment in health and disease, he described in detail the supreme importance of breastfeeding, detailed clear practical concepts for the weaning of infants and discussed the diagnosis and management of diseases of the mouth, ears, eyes and teeth of infants. Beaney was shunned by much of the established medical profession because of his self-promoting flamboyance and his egotism. However, an audit of surviving archives and of his published works affords him a place as another, hitherto unacknowledged true pioneer of Australian paediatrics.

Paediatric telecardiology services in Queensland: a review of three years' experience

Videoconferencing at 384 kbit/s for the transmission of echocardiograms has proved useful for the assessment of children with suspected cardiac disease, in regional areas of Queensland. A retrospective review of patient and management outcomes was conducted on cardiac teleconsultations performed at two regional hospitals during the period November 2000 to February 2004, inclusive. There were 106 echo studies. A subset of 72 cardiac teleconsultations performed between May 2001 and February 2004 was reviewed in detail. The median age of patients at the time of consultation was 3 months (range 1 day-17 years). Sixteen per cent of teleconsultations were classified as urgent and were conducted on the same day as referral. Following the videoconference, 90% of patients could be managed locally and reviewed by the paediatrician or visiting paediatric cardiologist during an outreach clinic. Six children (8%) had significant cardiac lesions that were initially managed locally, with subsequent elective transfer at the appropriate time for treatment. Only one child (1%) required urgent transfer to the tertiary centre for specialist care and surgery. Telecardiology was effective in accurately identifying congenital heart disease. Paediatric telecardiology is an evolving modality of assessment and communication, and is likely to result in continued improvements in patient care, patient outcomes and parental satisfaction, in provincial centres removed from the tertiary cardiac centre.