Paediatrics (RCH) - Theses
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ItemClowns in the midst: understanding clown doctors at The Royal Children's Hospital Melbourne( 2018)Clown doctors are a feature in paediatric hospitals, visiting children and families, providing a welcome escape from the reality of hospitalisation. Though the use of humour to improve health and wellbeing has been widely researched, limited exploration of the clown doctors has occurred. This study aims to elucidate the work of clown doctors within a major paediatric hospital. This was an ethnographic study. Ethnography is an innovative approach to paediatric research, giving an intricate view that is otherwise difficult to attain. Participants for this study included the clown doctors employed at The Royal Children’s Hospital, and every person they had a meaningful encounter with during the course of their work, including patients, families, clinical and non-clinical staff. Data was collected via participant observation, with approximately 1,500 hours of ‘clown ward rounds’ documented over one year. Furthermore, 25 hour-long semi-structured interviews were conducted with a range of key informants. A constructivist framework was used to analyse emergent concepts. Constructivism explores how relationships and interactions create the individual’s understanding of the world. Furthermore, how different understanding, or meaning, can be derived from interactions based on individual context, background, culture and personal history. When asking people about the clown doctors, most ascribed a function, such as: distraction, anxiety reduction and procedural assistance; entertainment and making people laugh; emotional support and providing comfort; and communication, including translating clinical information to families. These functional elements of the clown doctors are the result of a more complex, intimate human connection that develops due to the nature of clown doctors being low-status, open, vulnerable and, in particular, existing as outsiders to the medical establishment. Clown doctors use humour to break down the emotional barriers created by illness, which they achieve through being person-centric and offsetting medically driven interactions the hospital often demands. They empower patients, returning a sense of control that is generally absent for hospitalised children. While almost universally acknowledged as a positive addition to the hospital, most people who encounter the clown doctors have little conception about the scope of their work. Although clown doctors are often described in concrete clinical terms, their real power lies in their ability to connect with people, and the psychosocial advantages that connection provides. The results of this descriptive study deliver valuable insight and a comprehensive understanding of clown doctors and the complexity of human relationships within a major paediatric hospital. Through this research we can identify what the clown doctors bring to the hospital environment, how paediatric staff can employ their unique skills more effectively, and finally give long-overdue credence to the notion that laughter, mirth, creativity and child-like wonder has as much place in a hospital as medicine.
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ItemProximal femoral osteotomy in children and adolescents with cerebral palsy( 2018)Background Cerebral Palsy (CP) is the most common cause of physical disability affecting children in developed countries. Approximately one third of children with CP may develop hip displacement. Non-ambulant children at Gross Motor Function Classification System (GMFCS) levels IV and V are at highest risk. Without early detection through surveillance programs, hip displacement can progress to hip dislocation, which is frequently painful and negatively impacts health-related quality of life (HRQoL). Injections of Botulinum Neurotoxin A (BoNT-A) have no role, and soft tissue surgery has a limited role in preventing hip displacement in non-ambulant children with CP. Bony hip reconstruction surgery such as a proximal femoral osteotomy (PFO) is effective in stabilising the hip and HRQoL. PFOs include Femoral Derotation Osteotomies (FDO) which aim to improve the gait of an ambulant child (GMFCS I-III), and Varus Derotation Osteotomies (VDRO) which aim to contain the hips in non-ambulant children (GMFCS IV-V). However, PFOs can carry high risks, especially in children with medical co-morbidities such as respiratory disease, nutritional deficiencies, hypertonia and osteopenia. Aim This thesis involved a series of three studies, which aimed to expand our knowledge of the trainee learning curve, outcomes and adverse events relating to PFO in children and adolescents with CP. Method and Results A new implant combining locking and cannulated technology (Locking Cannulated Blade Plate, LCBP) was recently developed for use in PFO. A pilot study was performed on the first 25 patients who had surgery with the LCBP, at the Royal Children’s Hospital (RCH), Melbourne. This study established safety for use in children as young as three, with weights as low as eleven kilograms. A further prospective, parallel cohort study of 90 consecutive children with CP was conducted to compare the LCBP against with existing non-cannulated, non-locking implant (Angled Blade Plate, ABP). Technical and radiological outcomes of surgery were similar between implants. However, the surgical technique was reported by trainees to be easier when using the LCBP, with less technical errors. Approximately 60 percent of the children experienced minor adverse events including: constipation, inadequate pain control, and respiratory compromise. However, a CP specific tool was not available to classify the severity of events. Study three was performed to clarify the Modified Clavien-Dindo (MCD) system for lower limb surgery in children with CP and test its’ reliability for classifying adverse events. Very good reliability was demonstrated amongst members within a multidisciplinary team. Conclusion Novel findings from these studies may help improve the safety and efficacy of the management of hip displacement in children with CP. Further research should address the long-term outcomes of PFO in children with CP, evaluate the validity of the MCD for children in CP and determine if the MCD can be embedded in the electronic medical records (EMR) as a routine tool for audit and clinical research.
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ItemImproving oxygen therapy for children and newborns in Nigerian hospitals( 2018)Oxygen is a long-established medical therapy that can be life-saving for severely ill children admitted to hospital. Effective provision of oxygen to patients requires a multifaceted system that involves technical, clinical, supply chain, financing, and other managerial and policy elements. However, this system is currently difficult to achieve in many low-resource settings resulting in poor access to, and use of, oxygen and subsequent excess mortality. Previous work has shown that improved hospital oxygen systems can improve patient access to oxygen therapy and reduce inpatient case fatality rates from childhood pneumonia. However, studies have shown variable impact in different settings due to contextual factors that are not well understood. In addition, the burden of hypoxaemia and impact of oxygen on conditions other than pneumonia is unclear – particularly in the large neonatal population. This study aimed to understand how to improve oxygen systems in particular contexts, and generate evidence to support the scale-up of effective oxygen systems in Nigeria and globally. My realist review of past oxygen projects developed a theoretical framework describing how improved oxygen systems could improve clinical outcomes in particular contexts – highlighting the interaction between efforts to improve oxygen access and the clinical use of oxygen. My oxygen needs assessment in 12 secondary-level Nigerian hospitals provided detailed data on existing oxygen systems – highlighting the impact of poor power supplies, weak maintenance systems, and lack of pulse oximetry. My prospective cohort study provided new data on the epidemiology of hypoxaemia in the Nigerian context. This study showed high prevalence of hypoxaemia among admitted children and neonates with a range of conditions, highlighted the strong association between hypoxaemia and death, and demonstrated poor accuracy of clinical signs to predict hypoxaemia (particularly for children with non-respiratory conditions). My mixed-methods realist evaluation identified how pulse oximetry could be most effectively adopted into routine paediatric and neonatal care – highlighting the role of key influencers to model behaviour, practical training and ongoing encouragement, personal experience of benefit, and the reasons why nurses valued pulse oximetry. My stepped wedge trial evaluated the effect of our intervention (improved oxygen system) on clinical outcomes and care practices. This study demonstrated mortality benefit for children admitted with pneumonia, and suggested that the introduction of pulse oximetry generated most of this benefit by stimulating better use of existing oxygen supplies. We found no mortality benefit for children with other conditions or neonates, and detected an unexpected trend towards higher mortality in the “full oxygen system” period compared to the “pulse oximetry period” for neonates. Post-hoc analysis tested some potential explanatory theories for these findings – highlighting the effects of pre-existing oxygen access and external factors. In conclusion, improving oxygen systems is complex. The studies contained in this thesis have helped fill evidence gaps that are hindering oxygen policy and planning decision-making in Nigeria and globally. They have directly informed national and global policies and program planning.
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ItemHypoplastic left heart syndrome: development of a new animal model for hypothesis testing( 2018)INTRODUCTION: Hypoplastic left heart syndrome (HLHS) is a congenital heart defect that involves severe underdevelopment of the left-sided heart structures. Despite the severity of the cardiac deformity, HLHS is compatible with fetal life. In-utero survival of HLHS is facilitated by compensatory blood flow patterns facilitated by the presence of fetal shunts and the parallel arrangement of the fetal circulation. As the left ventricle (LV) is unable to perfuse the systemic circulation in HLHS, the fetal right ventricle (RV) is able to perfuse territories normally supplied by the LV during development via flow across the ductus arteriosus (DA) and aortic isthmus. However, after birth the DA closes and the RV is no longer able to compensate for the inadequate LV. As a result, newborns with HLHS develop circulatory collapse and die. At present, without intervention HLHS is universally fatal, with palliative surgery being the treatment option of choice offered by most institutions worldwide. Fundamental to the future study of HLHS and progress toward curative therapy is the creation of a clinically relevant mammalian animal model that facilitates hypothesis testing. Thus, the overall aim(s) of this thesis were to utilize an established fetal lamb model of the fetal cardiovascular system to develop a new stable, chronic, and clinically relevant fetal lamb model of congenital aortic stenosis (AoSt) (a condition known to evolve into HLHS in-utero); and quantify the growth-related changes in haemodynamics and cardiac morphology associated with the in-utero progression of the model using serial fetal echocardiography (Study 1). Additional studies using invasive cardiovascular instrumentation aimed to characterise the cardiovascular physiology of the fetal lamb model of congenital AoSt during fetal life (Study 2), the transition from fetus to newborn (Study 3), and closure of the DA (Study 4). METHODOLOGY: Surgery was performed in n=19 anaesthetised time-dated twin-pregnancy ewes (mean 91±3 days; term=147 days), with one fetus undergoing non-constrictive ascending aortic banding, and the second serving as the un-operated control. Serial fetal echocardiography studies were performed under maternal sedation at fortnightly intervals until near-term (140±1 days) in order to measure structural and functional changes in cardiac growth (Study 1). At near-term, sets of twin fetuses (n=12) were anaesthetised and instrumented with aortic (Ao), pulmonary arterial (PA) and left atrial (LA) fluid-filled pressure (P) catheters, and in a subgroup of fetuses (control; n=9, banded; n=4), an LV micromanometer catheter was placed. Haemodynamic and arterial blood gas measurements were made during fetal life (Study 2), as well as during the transition from fetus to newborn (Study 2), and after closure of the DA (Study 4). RESULTS: Echocardiography (Study 1) performed after non-occlusive banding of the ascending aorta of mid-gestation fetal lambs increased the peak ascending aortic (trans-stenosis) pressure gradient from 8±4mmHg at mid-gestation to 26±13 mmHg at near-term (p<0.001). Versus control animals, this pressure gradient was associated with increases in LV posterior wall (15%; p<0.05), and septal (14%; p<0.05), thickness, as well as a reduction in LV chamber short axis dimension during both systole (26%; p<0.001) and diastole (22%; p<0.001). These changes were also coupled with near-term increases in RVO (28%; p<0.005), HR (20%; p<0.001) and CVO (21%; p<0.001) compared to control animals. Invasive instrumentation (Study 2) demonstrated AoP, PAP and HR were similar between control and banded fetuses. However, LAP was paradoxically lower in banded fetuses versus controls (6.2±1.9 vs. 4.3±1.7 mmHg; p<0.05), while LV systolic pressure (56±9 vs. 75±7 mmHg; p<0.05) and LV dP/dtmax (1415±285 vs. 1930±504 mmHg; p<0.05) were higher in banded fetuses. Birth (Study 3) in banded fetuses was related to attenuation of the normal birth-related drop in PAP, as well as absence of the normal birth-related rise in AoP. Higher fetal LV systolic pressures were maintained after birth in banded animals, whereas LV dP/dtmax was reduced (p<0.05). Closure of the DA (Study 4) in banded animals was not associated with the normal rise in AoP seen in control animals. LAP decreased in banded animals after DA closure (32%; p<0.05) but remained unchanged in controls. Further, banded animals sustained hypoxic changes, manifest via reduced arterial blood pO2 (74.1±15.2 vs. 61.7±12.2 mmHg; p<0.05) after DA closure. CONCLUSION: Non-occlusive ascending aortic banding in mid-gestation fetal sheep is associated with a significant chronic rise in LV afterload, as well as substantial changes in LV growth patterns; manifest not only via alterations in LV wall thickness and cavity dimensions, but also in LV chamber geometry. Moreover, these changes are associated with increased right-heart blood flow and CVO, allowing fetuses to remain compatible with life in-utero. In addition, arterial blood pressures were maintained and the blood gas status largely unimpaired in fetal sheep after mid-gestation aortic banding. Although not associated with dramatic changes in haemodynamics and arterial blood gas status during fetal life, birth was associated with findings suggestive of changes in systemic, pulmonary and intra-cardiac blood flow patterns, as well as cardiac function; all of which have potential relevance to the clinical arena and early management of the newborn with HLHS. Finally, closure of the DA was associated with reduced systemic perfusion pressures, and hypoxia, findings akin to those seen in circulatory collapse of infants with HLHS. Therefore, given its favourable characteristics, this model is suitable for future hypothesis testing in the pathogenesis and pathophysiology of AoSt and HLHS.
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ItemFamily adaptation following paediatric acquired brain injury( 2017)Objective: This thesis aims to address the lack of evidence based research in interventions that promote family adaptation following paediatric acquired brain injury (ABI). It reports on the first social work clinical intervention trial designed to measure the effectiveness of a new family intervention titled ‘Family Forward’. This intervention was compared with ‘Usual Care’ social work practice to assess its efficacy in assisting families to make early adaptations during their child’s inpatient rehabilitation phase of care. Method: Participants were parents, caregivers and siblings of 47 children diagnosed with ABI and admitted to an inpatient rehabilitation service. Families were recruited prospectively and sequentially as their child was admitted to an inpatient rehabilitation ward at a statewide tertiary paediatric hospital. The ‘Usual Care’ group (n=22) recruitment, intervention and data collection was completed before the second phase of the intervention, ‘Family Forward’ (n=25) commenced. Patient characteristics were obtained from the child’s medical record. Families provided family demographic and psychosocial risk information using the Psychosocial Assessment Tool (PAT 2.0). Family adaptation outcomes were assessed using family functioning outcomes (Family Assessment Device – General Functioning: FAD-GF) and family management of the injured child’s care at home (Family Management Measure: FAMM). Family members’ appraisal of the child’s injury was also examined in relation to trauma, grief, emotional experience and injury perceptions (Impact of Event Scale – Revised: IES-R; Parent Experience of Childhood Illness: PECI; Brief Illness Perception Questionnaire: Brief-IPQ). Measures were completed at the child’s inpatient rehabilitation admission (pre-intervention), inpatient rehabilitation discharge (post-intervention) and six weeks post inpatient rehabilitation discharge (follow-up). Parents/caregivers and siblings also completed open-ended questions relating to the impact of the child’s injury on family relationships at follow-up. Social workers delivered the ‘Usual Care’ and ‘Family Forward’ interventions and completed the Social Work Activity Form (SWAF) measure at post-intervention and at follow-up. The SWAF measured the social work activity and the level of intensity of the interventions delivered to the families in the two groups. Results: Family adaptation outcomes (FAD-GF and FAMM) were similar for both groups at follow-up. The ‘Family Forward’ group had poorer family functioning pre-intervention (FAD-GF Family Forward mean = 1.626 SD = 0.391; Usual Care mean = 1.491 SD 0.394) and endured longer hospital admissions (Family Forward mean =56.4 days SD 46.1; Usual Care mean = 37.5 days SD 16.4) and inpatient rehabilitation admissions (Family Forward mean = 33.3 SD 29.0; Usual Care mean = 21.4 SD 13.5) than the Usual Care group. There were significant differences in relation to the social work activity and intensity of the interventions delivered to the two groups. The Family Forward group received more services in all areas of service delivery measured by the SWAF and there was an association between poorer family functioning and increased social work activity and level of intensity of the interventions delivered to this group. No significant group differences were found for family appraisal outcomes (IES-R, PECI and Brief IPQ) at any of the three time-points. Both groups reported more adaptive grief responses compared with the PECI normative sample. Trauma responses (IES-R) suggest adaptive family appraisal for both groups. However, the two groups continued to have depleted emotional resources (PECI scale) at follow-up. Parents and siblings also reflected on changes to family relationships at six weeks post discharge. Thematic analysis of free text identified themes common in both groups: ‘negative changes in sibling interactions’ and ‘sibling protectiveness of the injured child’. In addition to these themes, the families in the ‘Family Forward’ group described ‘increased expectation on sibling’; ‘family system challenges’; ‘balancing needs within the sibling subsystem’; and ‘adjustment to parenting’. Conclusions: As this is the first study of its kind, the results can begin to inform social work and rehabilitation clinicians alike about the early family adaptation experience and important foci for psychosocial interventions during a child’s inpatient rehabilitation.
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ItemPopulation-based screening for the prevention of rheumatic heart disease( 2017)Rheumatic heart disease (RHD) is a major cause of global morbidity and mortality, particularly affecting children and young adults in resource-limited settings. Most individuals are diagnosed at an advanced stage of disease, limiting opportunities for prevention. Population-based screening has the potential to detect individuals in an earlier, latent stage of disease, where secondary prevention may be most effective. Several countries, including Fiji, are considering the introduction of screening as part of RHD control. The aim of this thesis was to generate and compile evidence for policy makers in Fiji and other resource-limited settings to consider the viability, appropriateness and effectiveness of population-based screening for RHD. The thesis contains six studies, divided into three Parts, each investigating aspects of the evidence required for RHD screening policy. The first Part describes an evaluation of a screening test that may be viable in resourcelimited settings. Over two thousand school-aged children were screened by brieflytrained nurses, using focused cardiac ultrasound (FoCUS) in a study of diagnostic accuracy. The training curriculum was then adapted into a computer-based training course, and evaluated in another group of non-experts in Uganda. After brief training, non-expert nurses were able to perform FoCUS with high quality, and assess the presence and extent of valvular regurgitation. Screening by the nurses using FoCUS was accurate for the diagnosis of RHD, with a sensitivity of 84% and specificity of 86%. Computerbased training modules were highly effective in increasing the knowledge and confidence of non-expert health workers. The second Part describes an investigation of the natural history and outcomes of young people with screening-detected RHD in Fiji. Repeat echocardiography was performed on young people after screening, evaluating the change in echocardiographic diagnosis and severity after a median of 7.5 years. A cohort study compared the clinical outcomes for young people with screening-detected RHD with matched, screen-negative and clinically-diagnosed groups. The echocardiographic diagnosis remained stable or improved for the majority of young people, however, a proportion progressed to severe disease. In comparison to a matched, screen-negative cohort, young people with screening-detected, definite RHD had worse health outcomes, with 20% developing complications. The third Part describes an assessment of the current management and opportunities to improve secondary prevention in Fiji. The adherence of almost 500 young people was measured over a three-year period, and interviews were conducted with one hundred young people and their families. Adherence to secondary antibiotic prophylaxis after screening was found to be inadequate, with just 6% of individuals receiving sufficient injections to protect against disease progression. A range of factors influencing adherence were found, and strategies to improve secondary prevention were formulated. Despite a potentially viable test strategy, and documentation of worse health for young people with latent disease, the major deficiencies in secondary prevention indicate that screening is not currently effective for disease control in Fiji. Further population-based screening for RHD is therefore not appropriate at this time. RHD control efforts should focus on improvements to secondary prevention. Further research into RHD screening is needed for evidence-based policy, and could occur in parallel. The findings of this thesis have important policy, practice and research implications for the prevention of RHD in Fiji, and globally.
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ItemInvestigating and interpreting the use, costs, accessibility and organisation of healthcare services among children with cerebral palsy( 2016)Background and Rationale: Cerebral palsy is an umbrella term for a group of non-progressive disorders of movement and posture. Compared to their typically-developing peers, children with cerebral palsy are at an increased risk of multiple comorbidities and frequent acute illnesses that affect almost all of the organ systems, and as a consequence, have significantly greater medical care needs. There is growing interest internationally in investigating the patterns of medical service use among children with complex conditions such as cerebral palsy. It is hoped that a greater understanding of their healthcare needs could assist with decision making around health service delivery for this group. Aims: The aims of this thesis were to describe the patterns of medical service use among children with cerebral palsy, identify factors associated with the frequency and type of medical services used by this group, and compare their hospital admission and emergency department presentation characteristics with those of the general population. A secondary aim was to explore with parents the financial implications of having a child with additional medical care needs. Methods: Population cohorts of children with cerebral palsy and data linkage techniques, as well as survey methods, were used. The Victorian Cerebral Palsy Register was linked to the emergency department and inpatient databases of the Australian state of Victoria’s two paediatric hospitals to examine service use at these centres, and to the Victorian Admitted Episodes Dataset and Victorian Emergency Minimum Dataset to investigate statewide admissions and emergency department presentations respectively among population cerebral palsy cohorts. A purposefully-designed survey gathered information from parents on other medical services used, and on how they cope financially in light of their child’s medical care needs. Results: Of 2,183 children with cerebral palsy, 814 had at least one emergency department presentation and 1,443 had at least one admission at one of Victoria’s two paediatric hospitals over a five-year period, accounting for an average of 1,400 admissions and 700 emergency department presentations at the two hospitals each year. A higher than expected proportion of paediatric emergency department presentations were triaged as high urgency (71%) and resulted in a hospital admission (44%). Children with severe and/or complex cerebral palsy had more frequent admissions and emergency department presentations to the two hospitals, as well as higher re-admission rates. A similar pattern was observed when admissions and emergency department presentations at all hospitals in the state were investigated, those children with more severe and/or complex cerebral palsy having more hospital episodes each year. Compared to the general population of children, those with cerebral palsy had longer lengths of stay (median of 3 vs 2 nights; p<0.001), and more procedures (median of 2 vs 1 procedures; p<0.001) per multi-day admission, and more emergency department presentations that were preceded by an ambulance arrival (27% vs 8%; p<0.001), triaged as being of high urgency (66% vs 34%; p<0.001) and resulted in a hospital admission (38% vs 13%; p<0.001). Ultimately, they accrued higher hospital charges per episode. The types of paediatric specialists most often seen in outpatient settings were general or developmental paediatricians, orthopaedic surgeons, rehabilitation specialists, and neurologists. Most children received medical services from a number of different providers, in multiple different settings, and this continued into adolescence and early adulthood. Overall, the number and complexity of hospital episodes, the number of professionals involved in their medical management, and the proportion of families reporting financial difficulties all rose with increasing cerebral palsy severity and complexity. Conclusions and Significance: Through a series of data linkage studies and a purposefully-designed parent survey, this thesis provides new knowledge about medical service use among children with cerebral palsy. It provides, for the first time, objective population-level data on which future decisions around health service delivery for this patient group can be based, as well as highlighting some future research priorities.
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ItemIsotonic intravenous fluid for maintenance hydration in hospitalised children( 2015)Introduction This thesis comprises a systematic review, a laboratory based study, and a randomised controlled trial comparing isotonic with hypotonic intravenous fluid for maintenance hydration in children: the Paediatric Intravenous Maintenance Solution (PIMS) study. Objectives The general objective of this research was to study the use of isotonic intravenous fluid for maintenance hydration in children. Specific objectives were: • To establish the current evidence for the use of isotonic fluid, compared with hypotonic fluid (Chapter 2) by comparing the incidence of hyponatraemia and hypernatraemia, the effect on mean serum sodium concentration, and the incidence of attributable adverse effects. • To design a randomised controlled trial in a broad paediatric population comparing isotonic fluid with hypotonic fluid (Chapter 3). • To describe the effect of progressive dilution of blood samples with 0.45% sodium chloride with 5% glucose on measured concentrations of sodium and glucose, and to use these results to inform the PIMS study by identifying samples that were potentially contaminated with study fluid (Chapter 4). • To assess the risk of hyponatraemia when an isotonic fluid is compared with a hypotonic fluid for maintenance intravenous hydration in a broad paediatric population (Chapter 5); secondarily to compare the risk of hypernatraemia and other attributable adverse effects and outcomes. Methods Children aged between 3 months and 18 years requiring intravenous fluid to maintain hydration were the population of interest for this research. • A systematic review was conducted including randomised controlled trials which compared isotonic with hypotonic intravenous fluids for maintenance hydration in children. • A laboratory study sampled blood from three healthy adult volunteers. The blood was contaminated by 0.45% sodium chloride with 5% glucose using six different contamination ratios. The impact on measured concentrations of sodium and glucose was described. • A blinded, randomised controlled trial (the PIMS study) was designed and conducted, enrolling children who needed intravenous maintenance hydration for six hours or longer. With an online randomisation system that used unequal block sizes, patients were randomly assigned to receive either isotonic intravenous fluid containing 140mmol/L of sodium (Plasma-Lyte 148 with 5% glucose) or hypotonic fluid containing 77mmol/L of sodium (0.45% sodium chloride with 5% glucose) for 72 hours, or until their intravenous fluid requirement decreased to below 50% of standard maintenance rate. Assignment was stratified by baseline serum sodium level. Study investigators, treating clinicians, nurses, and patients were masked to treatment assignment. The primary outcome was the occurrence of hyponatraemia (serum sodium <135mmol/L with a decrease of at least 3mmol/L from baseline) during the treatment period, analysed by intention to treat. Results • The systematic review revealed a lack of evidence for the use of isotonic intravenous fluid for maintenance hydration outside of surgical or intensive care populations. In addition, there was limited evidence beyond the first 24 hours of therapy. • The laboratory study showed that a glucose level above 16.1mmol/L indicated that a decrease in measured sodium by at least 3mmol/L was a possible consequence of contamination of a blood sample with intravenous fluid. This was used as the basis of a sensitivity analysis within the PIMS study. • Over a three year period, 690 children were randomly assigned to receive either isotonic or hypotonic fluid. Of these patients, primary outcome data were available for 319 who received isotonic fluid and 322 who received hypotonic fluid. The PIMS study found that fewer patients given an isotonic fluid than those given a hypotonic fluid developed hyponatraemia (12 patients [4%] vs 35 [11%]; odds ratio [OR] 0.31, 95% CI 0.16 to 0.61; p=0.001) without evidence of an increase in adverse events. Conclusions • There was a lack of prior evidence in a broad paediatric population for the use of isotonic fluid over hypotonic fluid. • The use of isotonic intravenous fluid with a sodium concentration of 140mmol/L had a lower risk of hyponatraemia without an increase in adverse effects when compared with a fluid containing 77mmol/L of sodium. An isotonic fluid should be used as intravenous fluid for maintenance hydration in children.
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ItemA systematic evaluation of the neurosurgical application of perioperative and intraoperative diffusion MR tractography in paediatric epilepsy surgery( 2015)Epilepsy is a serious health condition affecting children worldwide. In a subset of these children, the epilepsy is refractory despite maximum appropriate medical therapies. Neurosurgical interventions aiming at resecting the seizure generating (epileptogenic) tissue provides the potential for seizure freedom in these children. The principle of epilepsy surgery is to maximally resect the epileptogenic tissues without injuring the eloquent brain regions, which includes both the cortical grey matter (GM) and the subcortical white matter tracts (WMTs). Injuries to these structures can lead to permanent neurological deficits. The surgical success depends on concordant preoperative and intraoperative localisation of both the seizure focus and the eloquent brain through the use of multimodal brain structural and functional neuroimaging techniques. Diffusion MR tractography is an increasingly utilised neuroimaging adjunct in epilepsy surgery that uniquely provides non-invasive virtual reconstructions of the WMT anatomy. Despite the growing popularity, its application in paediatric epilepsy surgery requires judicious evaluation, particularly with respect to its inherent technical limitations relevant to this age group. There is also a paucity of information regarding usefulness of a more sophisticated diffusion model and tractography algorithm in this clinical population. Using a cohort of 20 paediatric epilepsy surgical candidates, this PhD consists of three study experiments addressing both the technical and the clinical aspects of the diffusion MR tractography. Study experiment one (Chapter Five and Six) demonstrates the feasibility of developing a novel tractography methodology by adopting a more sophisticated diffusion model and the tractography algorithm. The study demonstrates highly accurate tractography results when validate against a set of predefined WMT anatomical criteria. Tractography generated in WMTs with distorted anatomy corresponds well with the functional MRI data and the direct brain electrostimulation findings. Study experiment two (Chapter Seven) evaluates the role of diffusion MR tractography to assess the degree of intraoperative WMT shift, and the intraoperative factors impacting on this shift. The study shows WMT shift is dynamic and occurs at both the global hemispheric and the regional WMT-based levels. The durotomy size, the resected lesion size and the presence of brain oedema are significant independent intraoperative variables affecting the WMT shift. Study experiment three (Chapter Eight) evaluates the association between the tractography-derived quantitative metrics and the perioperative functional states of the participants. The incomplete clinical data restricts the analysis to subgroup and case-based observations. The results suggest the adopted quantitative metrics are sensitive but non-specific imaging biomarkers of the underlying WMT microstructure changes, and do not consistently reflect the child’s postoperative function. Further methodological refinements are required to substantiate and to improve on this finding. This PhD provides a reliable technical framework for performing diffusion MR tractography in children. It also highlights the pertinent technical factors that need to be considered when utilising and interpreting diffusion MR tractography results in paediatric epilepsy surgery over both the perioperative and the intraoperative settings. Importantly, this PhD provides the basis for future research while continue searches for a more specific WMT imaging biomarker associating with the child’s postoperative functional state that is of both diagnostic and interventional significance.
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ItemVery often the answer's not black or white: current practice, clinician and parental experiences of genomic testing in paediatric genetics clinics( 2015)Developmental delay (DD) has been estimated to affect 1 – 3% of the population and the underlying cause often remains unknown. For parents, receiving a diagnosis for their child’s DD can be a source of validation, and may impact upon their child’s prognosis, treatment and access to available supports. New genetic technologies, chromosomal microarrays (CMA), are now used across Australia to help end the ‘diagnostic odyssey’ families often experience. CMA tests have the capacity to identify genetic changes at much higher resolutions than was previously possible, but may increase the complexity and uncertainty of results. There is no research into the process of these consultations and the way in which this information is communicated to patients attending a genetics clinic. Using qualitative techniques and guided by the frameworks of symbolic interactionism and interactional sociolinguistics, this study provides a rich and nuanced analysis of paediatric genetic consultations. A multi-layered approach was used, enabling investigations of both the ‘front stage’ (consultations) and ‘backstage’ (interviews with parents and clinicians) to facilitate and further understand emerging patterns. Four data sources were used: (1) pre-consultation surveys with parents (n=32); (2) audio-recordings from consultations (n=32); (3) post-consultation telephone interviews with parents (n=32); and (4) post-consultation interviews with clinical geneticists (n=10). Overwhelmingly, parents were complimentary regarding consultations and described feeling reassured. Those who were disappointed were largely parents who were desperate for a diagnosis. The vast majority of parents reported a positive relationship with the clinician and felt that the genetic information had been explained in a very useful manner. Clinicians described consultations as varied and dependent on many factors including parents’ hopes and diagnostic expectations. They identified their primary role as a diagnostician but also acknowledged the therapeutic benefits these consultations could provide to families. Clinicians displayed mixed opinions regarding new tests, appreciating the benefits while also wary of inherent complexities and uncertainties that more detailed genetic testing would bring. Seven phases were identified within consultations, and on average clinicians contributed more words than parents, however there was variation across and within consultations. Although content of consultations was extremely similar, clinicians appeared to have varied approaches, and different styles were described including the clinical assessment approach and conversational style. Some parents were able to describe their experiences of their child’s development as a ‘narrative’, while during other consultations clinicians seemingly had a checklist of closed questions. Most clinicians used an historical narrative to describe the evolution of genetic testing; comparing past and current limitations with the promise of future genomic technologies. Findings enabled the development of an ‘ideal’ consultation in this setting, which highlights the importance of a positive clinician-parent relationship, especially in light of diagnostic uncertainty and advancing genomic testing capabilities. Narrative medicine could play a valuable role both for parents and clinicians as they make sense of genomic testing and diagnostic uncertainty. With the impending introduction of whole genome sequencing into a clinical setting, now is an ideal time to reflect and learn from past and present experiences, in order to maximise the therapeutic potential of such scientific discoveries.