Loss of chance in medical negligence claims now a lost cause?

The question whether the loss of chance of a better medical outcome in cases of medical negligence should be recognised as actionable damage is ‘a question which has divided courts and commentators throughout the common law world.’ In April 2010, the High Court handed down its anticipated decision in the case of Tabet (by her Tutor Sheiban) v Gett (2010) 240 CLR 537. The issue considered by the court was whether the appellant could claim in negligence for the loss of a chance of a better medical outcome. This issue had not been considered by the High Court previously, the most relevant cases being Rufo v Hosking (2004) 61 NSWLR 678 and Gavalas v Singh (2001) 3 VLR 404. Claiming for a loss of chance in a personal injury action raises questions as to recognised damage and causation, and the members of the High Court considered both of these.

Advance directives, autonomy and the refusal of life-sustaining medical treatment

As Australian society 1s agemg, individuals are increasingly concerned about managing their future, including making decisions about the medical treatment they may wish to receive or refuse if they lose decision-making capacity. To date, there has been relatively little research into the extent to which legal regulation allows competent adults to make advance refusals of life-sustaining medical treatment that will bind health professionals and others when a decision needs to be made at a future time. This thesis aims to fill this gap in the research by presenting the results of research into the legal regulation of advance directives that refuse life-sustaining medical treatment. In the five papers that comprise this thesis, the law that governs this area is examined, and the ethical principle of autonomy is used to critically evaluate that law. The principal finding of this research is that the current scheme of regulation is ineffective to adequately promote the right of a competent adult to make binding advance directives about refusal of medical treatment. The research concludes that legislation should be enacted to enable individuals to complete an advance directive, only imposing restrictions to the extent that this is necessary to promote individual autonomy. The thesis first examines the principle of autonomy upon which the common law (and some statutory law) is expressed to be based, to determine whether that principle is an appropriate one to underpin regulation. 1 The finding of the research is that autonomy can be justified as an organising principle on a number of grounds: it is consistent with the values of a liberal democracy; over recent decades, it is a principle that has been even more prominent within the discipline of medical ethics; and it is the principle which underpins the legal regulation of a related topic, namely the contemporaneous refusal of medical treatment. Next, the thesis reviews the common law to determine whether it effectively achieves the goal of promoting autonomy by allowing a competent adult to make an advance directive refusing treatment that will operate if he or she later loses decision-making capacity. 2 This research finds that conunon law doctrine, as espoused by the judiciary, prioritises individual choice by recognising valid advance directives that refuse treatment as binding. However, the research also concludes that the common law, as applied by the judiciary in some cases, may not be effective to promote individual autonomy, as there have been a number of circumstances where advance directives that refuse treatment have not been followed. The thesis then examines the statutory regimes in Australia that regulate advance directives, with a focus on the regulation of advance refusals of life-sustaining medical treatment.3 This review commences with an examination ofparliamentary debates to establish why legislation was thought to be necessary. It then provides a detailed review of all of the statutory regimes, the extent to which the legislation regulates the form of advance directives, and the circumstances in which they can be completed, will operate and can be ignored by medical professionals. The research finds that legislation was enacted mainly to clarify the common law and bring a level of certainty to the field. Legislative regimes were thought to provide medical professionals with the assurance that compliance with an advance directive that refuses life-sustaining medical treatment will not expose them to legal sanction. However, the research also finds that the legislation places so many restrictions on when an advance directive refusing treatment can be made, or will operate, that they have not been successful in promoting individual autonomy.

Refusal of medical treatment : a child's prerogative?

Society has a need for children to be able to make health care decisions. Homeless children need access to health care. Parents may not be accessible or competent to consent to their child’s health care. The familial relationship may have broken down. Children may not want their parents to know about drug, alcohol or pregnancy related issues. There is legal and academic support for the right of children to make autonomous decisions with respect to their health care. However what these decisions cover and who can make them is not clear. Whether or not a minor has capacity and is therefore competent to consent to medical treatment is a question of law. Some states of Australia have enacted legislation, while others rely on the common law to determine this issue. At common law a minor is capable of giving consent to medical treatment when he or she achieves a sufficient understanding and intelligence to be able to understand fully what is proposed. Known as ‘Gillick competence’ this is a well known principle of law. The question posed by this paper is whether the decision of a ‘Gillick competent’ child can and should be overridden by the court?

A prospective cohort study of geriatric syndromes among older medical patients admitted to acute care hospitals

OBJECTIVES: To identify the prevalence of geriatric syndromes in the premorbid for all syndromes except falls (preadmission), admission, and discharge assessment periods and the incidence of new and significant worsening of existing syndromes at admission and discharge. DESIGN: Prospective cohort study. SETTING: Three acute care hospitals in Brisbane, Australia. PARTICIPANTS: Five hundred seventy-seven general medical patients aged 70 and older admitted to the hospital. MEASUREMENTS: Prevalence of syndromes in the premorbid (or preadmission for falls), admission, and discharge periods; incidence of new syndromes at admission and discharge; and significant worsening of existing syndromes at admission and discharge. RESULTS: The most frequently reported premorbid syndromes were bladder incontinence (44%), impairment in any activity of daily living (ADL) (42%). A high proportion (42%) experienced at least one fall in the 90 days before admission. Two-thirds of the participants experienced between one and five syndromes (cognitive impairment, dependence in any ADL item, bladder and bowel incontinence, pressure ulcer) before, at admission, and at discharge. A majority experienced one or two syndromes during the premorbid (49.4%), admission (57.0%), or discharge (49.0%) assessment period.The syndromes with a higher incidence of significant worsening at discharge (out of the proportion with the syndrome present premorbidly) were ADL limitation (33%), cognitive impairment (9%), and bladder incontinence (8%). Of the syndromes examined at discharge, a higher proportion of patients experienced the following new syndromes at discharge (absent premorbidly): ADL limitation (22%); and bladder incontinence (13%). CONCLUSION: Geriatric syndromes were highly prevalent. Many patients did not return to their premorbid function and acquired new syndromes.

Defences in medical negligence : to what extent has tort law reform in Australia limited the liability of health professionals?

Tort law reform has resulted in legislation being passed by all Australian jurisdictions in the past decade implementing the recommendations contained in the Ipp Report. The report was in response to a perceived crisis in medical indemnity insurance. The objective was to restrict and limit liability in negligence actions. This paper will consider to what extent the reforms have impacted on the liability of health professionals in medical negligence actions. After an analysis of the legislation, it will be argued in this paper that while there has been some limitation and restriction, courts have generally interpreted the civil liability reforms in compliance with the common law. It has been the impact of statutory limits on the assessment of damages through thresholds and caps which has limited the liability of health professionals in medical negligence actions.

Polycaprolactone-based scaffold plus rhBMP-2 in a sheep thoracic spine fusion model

We report the application of a novel scaffold design in a sheep thoracic spine model for spine deformity correction. The combination of the calcium-phosphate coated polycaprolactone scaffolds with recombinant human bone morphogenic protein-2 (rhBMP-2) are intended as a future bone graft substitute in ensuring the stability of bony intervertebral fusion. A solid free-form fabrication process based on melt extrusion has been utilized in the manufacturing of these scaffolds. To date there are no studies examining the use of such biodegradable implants in a sheep thoracic spine model. The success of anterior scoliosis surgery in humans depends on achieving a solid bony fusion between adjacent vertebrae after the intervertebral discs have been surgically cleared and the disc spaces filled with graft material. Due to limited availability of autograft, there is much current interest in the development of synthetic scaffolds in combination with growth factors such as recombinant human bone morphogenetic protein (rhBMP-2) to achieve a solid bony fusion following scoliosis surgery.

Evaluation of modal analysis techniques using physical models to detect osseointegration of implants in transfemoral amputees

Non-invasive vibration analysis has been used extensively to monitor the progression of dental implant healing and stabilization. It is now being considered as a method to monitor femoral implants in transfemoral amputees. This paper evaluates two modal analysis excitation methods and investigates their capabilities in detecting changes at the interface between the implant and the bone that occur during osseointegration. Excitation of bone-implant physical models with the electromagnetic shaker provided higher coherence values and a greater number of modes over the same frequency range when compared to the impact hammer. Differences were detected in the natural frequencies and fundamental mode shape of the model when the fit of the implant was altered in the bone. The ability to detect changes in the model dynamic properties demonstrates the potential of modal analysis in this application and warrants further investigation.

Tissue engineering bone - reconstruction of critical sized segmental bone defects in a large animal model

Currently, well established clinical therapeutic approaches for bone reconstruction are restricted to the transplantation of autografts and allografts, and the implantation of metal devices or ceramic-based implants to assist bone regeneration. Bone grafts possess osteoconductive and osteoinductive properties, their application, however, is associated with disadvantages. These include limited access and availability, donor site morbidity and haemorrhage, increased risk of infection, and insufficient transplant integration. As a result, recent research focuses on the development of complementary therapeutic concepts. The field of tissue engineering has emerged as an important alternative approach to bone regeneration. Tissue engineering unites aspects of cellular biology, biomechanical engineering, biomaterial sciences and trauma and orthopaedic surgery. To obtain approval by regulatory bodies for these novel therapeutic concepts the level of therapeutic benefit must be demonstrated rigorously in well characterized, clinically relevant animal models. Therefore, in this PhD project, a reproducible and clinically relevant, ovine, critically sized, high load bearing, tibial defect model was established and characterized as a prerequisite to assess the regenerative potential of a novel treatment concept in vivo involving a medical grade polycaprolactone and tricalciumphosphate based composite scaffold and recombinant human bone morphogenetic proteins.

Applications of medical image processing in the diagnosis and treatment of spinal deformity

In Chapter 10, Adam and Dougherty describe the application of medical image processing to the assessment and treatment of spinal deformity, with a focus on the surgical treatment of idiopathic scoliosis. The natural history of spinal deformity and current approaches to surgical and non-surgical treatment are briefly described, followed by an overview of current clinically used imaging modalities. The key metrics currently used to assess the severity and progression of spinal deformities from medical images are presented, followed by a discussion of the errors and uncertainties involved in manual measurements. This provides the context for an analysis of automated and semi-automated image processing approaches to measure spinal curve shape and severity in two and three dimensions.

Bayesian mixtures for modelling complex medical data : a case study in Parkinson’s disease

Mixture models are a flexible tool for unsupervised clustering that have found popularity in a vast array of research areas. In studies of medicine, the use of mixtures holds the potential to greatly enhance our understanding of patient responses through the identification of clinically meaningful clusters that, given the complexity of many data sources, may otherwise by intangible. Furthermore, when developed in the Bayesian framework, mixture models provide a natural means for capturing and propagating uncertainty in different aspects of a clustering solution, arguably resulting in richer analyses of the population under study. This thesis aims to investigate the use of Bayesian mixture models in analysing varied and detailed sources of patient information collected in the study of complex disease. The first aim of this thesis is to showcase the flexibility of mixture models in modelling markedly different types of data. In particular, we examine three common variants on the mixture model, namely, finite mixtures, Dirichlet Process mixtures and hidden Markov models. Beyond the development and application of these models to different sources of data, this thesis also focuses on modelling different aspects relating to uncertainty in clustering. Examples of clustering uncertainty considered are uncertainty in a patient’s true cluster membership and accounting for uncertainty in the true number of clusters present. Finally, this thesis aims to address and propose solutions to the task of comparing clustering solutions, whether this be comparing patients or observations assigned to different subgroups or comparing clustering solutions over multiple datasets. To address these aims, we consider a case study in Parkinson’s disease (PD), a complex and commonly diagnosed neurodegenerative disorder. In particular, two commonly collected sources of patient information are considered. The first source of data are on symptoms associated with PD, recorded using the Unified Parkinson’s Disease Rating Scale (UPDRS) and constitutes the first half of this thesis. The second half of this thesis is dedicated to the analysis of microelectrode recordings collected during Deep Brain Stimulation (DBS), a popular palliative treatment for advanced PD. Analysis of this second source of data centers on the problems of unsupervised detection and sorting of action potentials or "spikes" in recordings of multiple cell activity, providing valuable information on real time neural activity in the brain.

Towards semantic search and inference in electronic medical records : an approach using concept-based information retrieval

For more than a decade research in the field of context aware computing has aimed to find ways to exploit situational information that can be detected by mobile computing and sensor technologies. The goal is to provide people with new and improved applications, enhanced functionality and better use experience (Dey, 2001). Early applications focused on representing or computing on physical parameters, such as showing your location and the location of people or things around you. Such applications might show where the next bus is, which of your friends is in the vicinity and so on. With the advent of social networking software and microblogging sites such as Facebook and Twitter, recommender systems and so on context-aware computing is moving towards mining the social web in order to provide better representations and understanding of context, including social context. In this paper we begin by recapping different theoretical framings of context. We then discuss the problem of context- aware computing from a design perspective.

Overlapping medical alarms are almost indiscriminable

Objective: We explore how accurately and quickly nurses can identify melodic medical equipment alarms when no mnemonics are used, when alarms may overlap, and when concurrent tasks are performed. Background: The international standard IEC 60601-1-8 (International Electrotechnical Commission, 2005) has proposed simple melodies to distinguish seven alarm sources. Previous studies with nonmedical participants reveal poor learning of melodic alarms and persistent confusions between some of them. The effects of domain expertise, concurrent tasks, and alarm overlaps are unknown. Method: Fourteen intensive care and general medical unit nurses learned the melodic alarms without mnemonics in two sessions on separate days. In the second half of Day 2 the nurses identified single alarms or pairs of alarms played in sequential, partially overlapping, or nearly completely overlapping configurations. For half the experimental blocks nurses performed a concurrent mental arithmetic task. Results: Nurses' learning was poor and was no better than the learning of nonnurses in a previous study. Nurses showed the previously noted confusions between alarms. Overlapping alarms were exceptionally difficult to identify. The concurrent task affected response time but not accuracy. Conclusion: Because of a failure of auditory stream segregation, the melodic alarms cannot be discriminated when they overlap. Directives to sequence the sounding of alarms in medical electrical equipment must be strictly adhered to, or the alarms must redesigned to support better auditory streaming. Application: Actual or potential uses of this research include the implementation of IEC 60601-1-8 alarms in medical electrical equipment.

Learnability and discriminability of melodic medical equipment alarms

Melodic alarms proposed in the IEC 60601-1-8 standard for medical electrical equipment were tested for learnability and discriminability. Thirty-three non-anaesthetist participants learned the alarms over two sessions of practice, with or without mnemonics suggested in the standard. Fewer than 30% of participants could identify the alarms with 100% accuracy at the end of practice. Confusions persisted between pairs of alarms, especially if mnemonics were used during learning (p = 0.011). Participants responded faster (p < 0.00001) and more accurately (p = 0.002) to medium priority alarms than to high priority alarms, even though they rated the high priority alarms as sounding more urgent (p < 0.00001). Participants with at least 1 year of formal musical training identified the alarms more accurately (p = 0.0002) than musically untrained participants, and found the task easier overall (p < 0.00001). More intensive studies of the IEC 60601-1-8 alarms are needed for their effectiveness to be determined.