Development Of Novel Methods For Non-invasive Measurement Of Cardiac Output And Lung Volume During Anaesthesia
Funder
National Health and Medical Research Council
Funding Amount
$257,970.00
Summary
In Australia approximately 2 million anaesthetic procedures are performed annually. Approximately one patient in 20,000 dies during or shortly after an anaesthetic from complications related to the anaesthetic itself, and as many as one in 170 suffers severe complications. Mortality and severe morbidity are often ultimately associated with lack of oxygen in the tissues. Oxygen is transported from the lungs to the tissues by the blood. The oxygen content of arterial blood is monitored by pulse ox ....In Australia approximately 2 million anaesthetic procedures are performed annually. Approximately one patient in 20,000 dies during or shortly after an anaesthetic from complications related to the anaesthetic itself, and as many as one in 170 suffers severe complications. Mortality and severe morbidity are often ultimately associated with lack of oxygen in the tissues. Oxygen is transported from the lungs to the tissues by the blood. The oxygen content of arterial blood is monitored by pulse oximetry during every anaesthetic, but blood flow is not. Cardiac output is measured in only a very small proportion of anaesthetised patients using intravenous catheters that pass through the heart to the lungs. This procedure is invasive and is associated with significant morbidity and mortality. At present there is no easy way to monitor cardiac output non-invasively during anaesthesia. Our proposed research project, currently underway in conjunction with an industrial partner, is aimed at the development of a reliable, rapidly repeating, non-invasive method for monitoring total cardiac output and lung volume in every patient who has an anaesthetic. The purpose of the new monitor is to ensure that potential problems with oxygen supply to the tissues are detected and corrected promptly. Our new monitoring technique is computer-controlled, can function without intervention by the anaesthetist and has very few side-effects. It can be added to any anaesthetic machine. Such a measurement technique is likely to have an impact on anaesthesia similar to that of pulse oximetry in the 1980's, and, if suitably adapted, is likely to find applications in other fields, such as intensive care, sports medicine, the respiratory function laboratory and in veterinary medicine.Read moreRead less
Are Healthcare Interventions Exacerbating Alzheimer's Disease (AHEAD)
Funder
National Health and Medical Research Council
Funding Amount
$709,803.00
Summary
The AHEAD Study will assess the impact of anaesthesia and surgery on cognitive function in patients with Mild Cognitive Impairment or mild Alzheimer's Disease. Such effects have not been established. With an ageing population being increasingly exposed to healthcare procedures requiring anaesthesia or sedation, any negative impact needs to be identified so that therapeutic decisions may be informed and future research appropriately targeted.
Closing The Gap: Implementing Effective Treatments To Improve Post-operative Nausea And Vomiting
Funder
National Health and Medical Research Council
Funding Amount
$175,303.00
Summary
Nausea and vomiting are common after surgery, concern 80% people undergoing surgery, and are managed by drugs with unwanted side effects. High quality evidence supports acupuncture being a safe and effective non-drug therapy for this complaint. This study will examine if and how acupuncture can be delivered by doctors and nurses around operation time. In future, people may have the choice of using acupuncture or drugs, or both, for preventing or treating nausea and vomiting after surgery.
Linking Of Physiological Models Of Iv Anaesthetic Disposition With Models Of The Cardio- And Cerebro-vascular Systems
Funder
National Health and Medical Research Council
Funding Amount
$227,036.00
Summary
On average, nearly 1 in 10 Australians are anaesthetised each year. Most cases include an injection of either thiopentone or propofol directly into a vein. These drugs quickly produce the desired loss of consciousness, but can also produce significant undesirable effects on the circulatory system. To date, anaesthetists have relied on their accumulated experience to choose doses of these drugs that achieve an appropriate balance between their desirable and undesirable effects. However, the scien ....On average, nearly 1 in 10 Australians are anaesthetised each year. Most cases include an injection of either thiopentone or propofol directly into a vein. These drugs quickly produce the desired loss of consciousness, but can also produce significant undesirable effects on the circulatory system. To date, anaesthetists have relied on their accumulated experience to choose doses of these drugs that achieve an appropriate balance between their desirable and undesirable effects. However, the scientific basis of this process was poorly understood. Consequently, we conducted experiments in sheep in which we showed that the level of unconsciousness produced by these drugs depended on their concentration in the brain. Each sheep was unharmed and could be studied repeatedly. We established the important factors that influenced this brain concentration, and developed a unique computer model of the processes governing the desirable effects of thiopentone and propofol. However, understanding of what influences the undesirable effects of these drugs is less well developed. In this project, we propose a series of experiments in which we inject the thiopentone and propofol in special sites within the sheep so that we achieve low concentrations in some parts of the body, but high concentrations in others, while also measuring their undesirable effects. This will show which sites in the body high concentrations of drug should be avoided to minimise these undesirable effects. Another series of studies will be used to extend our computer model so that it can predict these undesirable effects. This extended model will allow anaesthetists to visualise and understand the fundamental factors influencing both the desirable and undesirable effects of thiopentone and propofol. This in turn will lead to dose strategies that help the anaesthetist maximise the desirable effects, while minimising the undesirable, in individual patients.Read moreRead less
Cash Transfers And Behaviour Change Communications To Reduce Child Undernutrition In Rural Bangladesh: A Cluster Randomized Controlled Trial To Determine The Most Effective Combination Of Interventions.
Funder
National Health and Medical Research Council
Funding Amount
$3,415,801.00
Summary
Under-nutrition of children remains a major global public health problem. Tackling this problem will require more evidence about what combination of nutrition-specific and nutrition sensitive interventions is most effective in reducing child undernutrition. We plan a large scale trial in rural Bangladesh to compare the effects of communications about nutrition with mobile phones and cash transfers in preventing child malnutrition.
The Influence Of Anaesthetic Depth On Patient Outcome After Major Surgery
Funder
National Health and Medical Research Council
Funding Amount
$2,893,795.00
Summary
Millions of high-risk patients have general anaesthesia for major surgery worldwide every year, but the optimal depth of anaesthesia for these patients is not known. The aim of this large randomised trial is to determine the impact of light versus deep general anaesthesia on survival at one year postoperatively in 6,500 older patients. If light anaesthesia is associated with better survival, this result will be immediately implementable, will save lives and will reduce the costs of care.
It is known that about 10% of patients over the age of 55 have difficulty with cognition and thinking 3 months after surgery and anaesthesia. Over 2 million operations involving anaesthesia are administered in Australia every year and increasingly the patients are elderly and thus exposed to the risk of cognitive decline after surgery. We have preliminary data showing that people who have mild changes in cognitive function before the surgery (known as mild cognitive impairment) are susceptible t ....It is known that about 10% of patients over the age of 55 have difficulty with cognition and thinking 3 months after surgery and anaesthesia. Over 2 million operations involving anaesthesia are administered in Australia every year and increasingly the patients are elderly and thus exposed to the risk of cognitive decline after surgery. We have preliminary data showing that people who have mild changes in cognitive function before the surgery (known as mild cognitive impairment) are susceptible to further cognitive decline after anaesthesia and surgery. In order to explore the relationship between preoperative cognitive function and postoperative cognitive decline we plan to measure cognition in patients scheduled for elective hip replacement surgery. This is done by asking patients to complete a standard battery of cognitive tests. We will be then able to identify those patients who already have mild cognitive impairment before surgery and by repeated testing after the operation will be able to demonstrate if preoperative cognitive status is a determinant of postoperative cognitive dysfunction. The primary aim of the research is to test whether cognitive impairment before surgery leads to cognitive deficit after surgery in patients over the age of 65 undergoing total hip replacement surgery. The study will also establish the prevalence of pre-operative mild cognitive impairment and the magnitude of postoperative cognitive dysfunction after surgery in this patient group. The study will explore the relationship between preoperative cognitive status and postoperative cognitive deficit , providing information about the incidence, natural history and risk factors of postoperative cognitive deficit. This work will enable further research to isolate specific causative factors and identify therapeutic and prophylactic strategies.Read moreRead less
Molecular Mechanisms Underlying Recovery From General Anaesthesia
Funder
National Health and Medical Research Council
Funding Amount
$335,983.00
Summary
Even though general anaesthesia is an extremely common and safe procedure, doctors do not really know how it works. We have found that general anaesthetics might work in two steps, by first promoting natural sleep, and then by impairing communication between all nerve cells in the brain. It is this second step that makes surgery possible, but also makes recovery difficult – especially among patients with brain disorders. Understanding these mechanisms will promote better anaesthesia procedures.