Medical Education - Research Publications
Now showing items 1-12 of 497
Rare presentation of Wegener's granulomatosis in the pituitary gland: Case report and literature review
(ELSEVIER SCI LTD, 2017-01-01)
INTRODUCTION: Wegener's granulomatosis (WG) is a systemic vasculitis that can affect a variety of organs including ear, nose and throat, lungs and kidneys. However WG is unusual in the pituitary and rare in the central nervous system. PRESENTATION OF CASE: A 56-year-old male with likely WG presented with polyuria and polydipsia despite six months of conservative medical management. MRI scanning revealed an enlarging heterogeneously enhancing pituitary gland. Following endoscopic transsphenoidal pituitary biopsy and debulking, final tissue pathology was diagnostic for WG in the pituitary gland. DISCUSSION: Diagnosis remains difficult but most patients present with central diabetes insipidus (CDI) as well as varying degrees of hypopituitarism on a background of disease activity in other organs. Clinical judgment needs to balance the need for invasive surgical tissue diagnosis with increasing immunosuppressive therapy. CONCLUSION: It is important to consider this rare complication of WG to ensure timely diagnosis and management.
Perioperative blood management programme reduces the use of allogenic blood transfusion in patients undergoing total hip and knee arthroplasty
BACKGROUND: Optimisation of blood management in total hip (THA) and knee arthroplasty (TKA) is associated with improved patient outcomes. This study aimed to establish the effectiveness of a perioperative blood management programme in improving postoperative haemoglobin (Hb) and reducing the rate of allogenic blood transfusion. METHODS: This retrospective before and after study involves 200 consecutive patients undergoing elective TKA and THA before (Usual Care group) and after (Intervention group) the introduction of a blood management programme in an Australian teaching hospital. Patients in the Intervention group underwent preoperative treatment for anaemia and received intraoperative tranexamic acid (15 mg/kg). The primary outcomes were to compare postoperative Hb levels and the rate of blood transfusion. Secondary outcomes included measurements of total amount of allogenic blood transfused, transfusion-related complications, postoperative complications, need for inpatient rehabilitation and duration of hospital stay. RESULTS: There were no differences between baseline characteristics between groups. The mean (SD) preoperative Hb was higher in the Intervention group compared to that in the Usual Care group: 138.7 (13.9) vs. 133.4 (13.9) g/L, p = 0.008, respectively. The postoperative day 1 Hb, lowest postoperative Hb and discharge Hb were all higher in the Intervention group (p < 0.001). Blood transfusion requirements were lower in the Intervention group compared to the Usual Care group (6 vs. 20 %, p = 0.003). There were no differences in any of the secondary outcomes measured. Patients who were anaemic preoperatively and who underwent Hb optimisation had higher Hb levels postoperatively (odds ratio 5.7; 95 % CI 1.3 to 26.5; p = 0.024). CONCLUSIONS: The introduction of a perioperative blood optimisation programme improved postoperative Hb levels and reduced the rate of allogenic blood transfusion.
The Many Organisational Factors Relevant to Planning Change in Emergency Care Departments: A Qualitative Study to Inform a Cluster Randomised Controlled Trial Aiming to Improve the Management of Patients with Mild Traumatic Brain Injuries
(PUBLIC LIBRARY SCIENCE, 2016-02-04)
BACKGROUND: The Neurotrauma Evidence Translation (NET) Trial aims to design and evaluate the effectiveness of a targeted theory-and evidence-informed intervention to increase the uptake of evidence-based recommended practices for the management of patients who present to an emergency department (ED) with mild head injuries. When designing interventions to bring about change in organisational settings such as the ED, it is important to understand the impact of the context to ensure successful implementation of practice change. Few studies explicitly use organisational theory to study which factors are likely to be most important to address when planning change processes in the ED. Yet, this setting may have a unique set of organisational pressures that need to be taken into account when implementing new clinical practices. This paper aims to provide an in depth analysis of the organisational context in which ED management of mild head injuries and implementation of new practices occurs, drawing upon organisational level theory. METHODS: Semi-structured interviews were conducted with ED staff in Australia. The interviews explored the organisational context in relation to change and organisational factors influencing the management of patients presenting with mild head injuries. Two researchers coded the interview transcripts using thematic content analysis. The "model of diffusion in service organisations" was used to guide analyses and organisation of the results. RESULTS: Nine directors, 20 doctors and 13 nurses of 13 hospitals were interviewed. With regard to characteristics of the innovation (i.e. the recommended practices) the most important factor was whether they were perceived as being in line with values and needs. Tension for change (the degree to which stakeholders perceive the current situation as intolerable or needing change) was relatively low for managing acute mild head injury symptoms, and mixed for managing longer-term symptoms (higher change commitment, but relatively low change efficacy). Regarding implementation processes, the importance of (visible) senior leadership for all professions involved was identified as a critical factor. An unpredictable and hectic environment brings challenges in creating an environment in which team-based and organisational learning can thrive (system antecedents for innovation). In addition, the position of the ED as the entry-point of the hospital points to the relevance of securing buy-in from other units. CONCLUSIONS: We identified several organisational factors relevant to realising change in ED management of patients who present with mild head injuries. These factors will inform the intervention design and process evaluation in a trial evaluating the effectiveness of our implementation intervention.
Super-Selective Mesenteric Embolization Provides Effective Control of Lower GI Bleeding
(HINDAWI LTD, 2017-01-01)
Introduction. We aimed to assess the efficacy and safety of digital subtraction angiography (DSA) and super-selective mesenteric artery embolization (SMAE) in managing lower GI bleeding (LGIB). Method. A retrospective case series of patients with LGIB treated with SMAE in our health service. Patients with confirmed active LGIB, on either radionuclide scintigraphy (RS) or contrast-enhanced multidetector CT angiography (CE-MDCT), were referred for DSA +/- SMAE. Data collected included patient characteristics, screening modality, bleeding territory, embolization technique, technical and clinical success, short-term to medium-term complications, 30-day mortality, and progression to surgery related to procedural failure or complications. Results. There were fifty-five hospital admissions with acute unstable lower gastrointestinal bleeding which were demonstrable on CE-MDCT or RS over a 31-month period. Eighteen patients proceed to embolization, with immediate success in all. Eight patients (44%) had clinical rebleeding after intervention, warranting repeated imaging. Only one case (5.6%) demonstrated radiological rebleeding and was reembolized. Complication rate was excellent: no bowel ischaemia, ischaemic stricture, progression to surgery, or 30-day mortality. Conclusion. SMAE is a viable, safe, and effective first-line management for localised LGIB. Our results overall compare favourably with the published experiences of other institutions. It is now accepted practice at our institution to manage localised LGIB with embolization.
Immunological profiling of molecularly classified high-risk endometrial cancers identifies POLE-mutant and microsatellite unstable carcinomas as candidates for checkpoint inhibition
(TAYLOR & FRANCIS INC, 2017-01-01)
High-risk endometrial cancer (EC) is an aggressive disease for which new therapeutic options are needed. Aims of this study were to validate the enhanced immune response in highly mutated ECs and to explore immune profiles in other EC subgroups. We evaluated immune infiltration in 116 high-risk ECs from the TransPORTEC consortium, previously classified into four molecular subtypes: (i) ultramutated POLE exonuclease domain-mutant ECs (POLE-mutant); (ii) hypermutated microsatellite unstable (MSI); (iii) p53-mutant; and (iv) no specific molecular profile (NSMP). Within The Cancer Genome Atlas (TCGA) EC cohort, significantly higher numbers of predicted neoantigens were demonstrated in POLE-mutant and MSI tumors compared with NSMP and p53-mutants. This was reflected by enhanced immune expression and infiltration in POLE-mutant and MSI tumors in both the TCGA cohort (mRNA expression) and the TransPORTEC cohort (immunohistochemistry) with high infiltration of CD8+ (90% and 69%), PD-1+ (73% and 69%) and PD-L1+ immune cells (100% and 71%). Notably, a subset of p53-mutant and NSMP cancers was characterized by signs of an antitumor immune response (43% and 31% of tumors with high infiltration of CD8+ cells, respectively), despite a low number of predicted neoantigens. In conclusion, the presence of enhanced immune infiltration, particularly high numbers of PD-1 and PD-L1 positive cells, in highly mutated, neoantigen-rich POLE-mutant and MSI endometrial tumors suggests sensitivity to immune checkpoint inhibitors.
Immune function biomarker QuantiFERON-monitor is associated with infection risk in cirrhotic patients
(BAISHIDENG PUBLISHING GROUP INC, 2016-12-18)
AIM: To investigate whether a novel immune function biomarker QuantiFERON-Monitor (QFM) can identify cirrhotic patients at greatest risk of infection. METHODS: Adult cirrhotic patients on the liver transplant waiting list were recruited for this observational cohort study from a tertiary liver transplant referral unit. The immune function biomarker, QFM was performed using the same method as the widely available Quantiferon-gold assay, and measures output in interferon gamma in IU/mL after dual stimulation of the innate and adaptive immune systems. Ninety-one cirrhotic patients were recruited, with 47 (52%) transplanted on the day of their QFM. The remaining 44 (48%) were monitored for infections until transplant, death, or census date of 1st February 2014. RESULTS: Cirrhotic patients express a median QFM significantly lower than healthy controls (94.5 IU/mL vs 423 IU/mL), demonstrating that they are severely immunosuppressed. Several factors including model for end stage liver disease, presence of hepatocellular carcinoma, bilirubin, international normalized ratio and haemoglobin were associated with QFM on univariate analysis. Disease aetiology did not appear to impact QFM. On multivariate analysis, only Child-Pugh score and urea were significantly associated with a patient's immune function as objectively measured by QFM. In the 44 patients who were not transplanted immediately after their blood test and could be monitored for subsequent infection risk, 13 (29.5%) experienced a pre-transplant infection a median 20 d (range 2-182) post-test. QFM < 214 IU/mL was associated with HR = 4.1 (P = 0.01) for infection. A very low QFM < 30 IU/mL was significantly associated (P = 0.003) with death in three patients who died while awaiting transplantation (HR = 56.6). CONCLUSION: QFM is lower in cirrhotics, allowing objective determinations of an individual's unique level of immune dysfunction. Low QFM was associated with increased susceptibility to infection.
Efficacy and safety of tenofovir in chronic hepatitis B: Australian real world experience
(BAISHIDENG PUBLISHING GROUP INC, 2017-01-08)
AIM: To evaluate the long-term treatment outcomes of tenofovir therapy in patients in a real world Australian tertiary care setting. METHODS: We performed a retrospective analysis of treatment outcomes among treatment-naïve and treatment-experienced patients receiving a minimum 3 mo tenofovir therapy through St Vincent's Hospital Melbourne, Australia. We included patients receiving tenofovir [tenofovir disoproxil fumarate (TDF)] monotherapy, as well as patients treated with TDF in combination with a second antiviral agent. Patients were excluded if they demonstrated human immune-deficiency virus/hepatitis C virus/hepatitis delta virus coinfection or were less than 18 years of age. We considered virological and biochemical response, as well as safety outcomes. Virological response was determined by measurement of hepatitis B virus (HBV) DNA using sensitive assays; biochemical response was determined via serum liver function tests; histological response was determined from liver biopsy and fibroscan; safety analysis focused on glomerular renal function and bone mineral density. The primary efficacy endpoint was complete virological suppression over time, defined by HBV DNA < 20 IU/mL. Secondary efficacy endpoints included rates of biochemical response, and HB e antigen (HBeAg)/HB surface antigen loss and seroconversion over time. RESULTS: Ninety-two patients were identified who fulfilled the enrolment criteria. Median follow-up was 26 mo (range 3-114). Mean age was 46 (24-78) years, 64 (70%) were male and 77 (84%) were of Asian origin. 55 (60%) patients were treatment-naïve and 62 patients (67%) were HBeAg-negative. Complete virological suppression was achieved by 45/65 (71%) patients at 12 mo, 37/46 (80%) at 24 mo and 25/28 (89%) at 36 mo. Partial virological response (HBV DNA 20-2000 IU/mL) was achieved by 89/92 (96.7%) of patients. Multivariate analysis showed a significant relationship between virological suppression at end of follow-up and baseline HBV DNA level (OR = 0.897, 95%CI: 0.833-0.967, P = 0.0046) and HBeAg positive status (OR = 0.373, 95%CI: 0.183-0.762, P = 0.0069). There was no difference in response comparing treatment-naïve and treatment-experienced patients. Three episodes of virological breakthrough occurred in the setting of non-compliance. Tenofovir therapy was well tolerated. CONCLUSION: Tenofovir is an efficacious, safe and well-tolerated treatment in an Australian real-world tertiary care setting. Our data are similar to the reported experience from registration trials.
White matter integrity as a predictor of response to treatment in first episode psychosis
(OXFORD UNIV PRESS, 2014-01-01)
The integrity of brain white matter connections is central to a patient's ability to respond to pharmacological interventions. This study tested this hypothesis using a specific measure of white matter integrity, and examining its relationship to treatment response using a prospective design in patients within their first episode of psychosis. Diffusion tensor imaging data were acquired in 63 patients with first episode psychosis and 52 healthy control subjects (baseline). Response was assessed after 12 weeks and patients were classified as responders or non-responders according to treatment outcome. At this second time-point, they also underwent a second diffusion tensor imaging scan. Tract-based spatial statistics were used to assess fractional anisotropy as a marker of white matter integrity. At baseline, non-responders showed lower fractional anisotropy than both responders and healthy control subjects (P < 0.05; family-wise error-corrected), mainly in the uncinate, cingulum and corpus callosum, whereas responders were indistinguishable from healthy control subjects. After 12 weeks, there was an increase in fractional anisotropy in both responders and non-responders, positively correlated with antipsychotic exposure. This represents one of the largest, controlled investigations of white matter integrity and response to antipsychotic treatment early in psychosis. These data, together with earlier findings on cortical grey matter, suggest that grey and white matter integrity at the start of treatment is an important moderator of response to antipsychotics. These findings can inform patient stratification to anticipate care needs, and raise the possibility that antipsychotics may restore white matter integrity as part of the therapeutic response.
A prospective case series for a minimally invasive internal fixation device for anterior pelvic ring fractures
(BIOMED CENTRAL LTD, 2016-11-08)
BACKGROUND: External fixation is commonly used as a means of definitive fixation of pelvic fractures. Pin site infection is common, with some cases of osteomyelitis and inpatient nursing can be challenging. The aim of this study is to report the outcomes and complications of an alternative minimally invasive technique, known as INFIX, utilising spinal pedicle screws inserted into the supra-acetabular bone and connected by a subcutaneous rod. METHODS: A single-centre prospective case series was performed. The primary outcome measures were fracture stability and displacement at time of implant removal and intra- and post-operative complications. RESULTS: Twenty-one patients were recruited, with 85.7 % of fractures being lateral compression type. Mean follow-up was 342 days. Mean application time was 51 min (range 44-65). Nineteen were removed electively, with mean time to removal 109 days. All cases were stable with no displacement. Two cases were removed emergently, one due to wound infection and the other due to lateral femoral cutaneous nerve neuropathic pain. Twelve patients sustained a lateral femoral cutaneous nerve palsy, with 20/42 nerves being affected. Improvement in all lateral femoral cutaneous nerve symptoms were reported with removal. Nine patients developed asymptomatic heterotopic ossification, and there were three deep infections and one symptomatic due to the bar. CONCLUSIONS: Minimally invasive internal fixation with the INFIX for anterior pelvic ring fractures is an alternative to anterior external fixation. However, a higher rate of lateral femoral cutaneous nerve palsy is noted, and the implant is not well tolerated by all patients. Further studies are required to define fracture types and patients best suited to the technique and how LFCN complications may be minimised. TRIAL REGISTRATION: ACTRN12616001421426 . Registered 12 October 2016. Retrospectively registered.
Individualized prediction of illness course at the first psychotic episode: a support vector machine MRI study
(CAMBRIDGE UNIV PRESS, 2012-05-01)
BACKGROUND: To date, magnetic resonance imaging (MRI) has made little impact on the diagnosis and monitoring of psychoses in individual patients. In this study, we used a support vector machine (SVM) whole-brain classification approach to predict future illness course at the individual level from MRI data obtained at the first psychotic episode. METHOD: One hundred patients at their first psychotic episode and 91 healthy controls had an MRI scan. Patients were re-evaluated 6.2 years (s.d.=2.3) later, and were classified as having a continuous, episodic or intermediate illness course. Twenty-eight subjects with a continuous course were compared with 28 patients with an episodic course and with 28 healthy controls. We trained each SVM classifier independently for the following contrasts: continuous versus episodic, continuous versus healthy controls, and episodic versus healthy controls. RESULTS: At baseline, patients with a continuous course were already distinguishable, with significance above chance level, from both patients with an episodic course (p=0.004, sensitivity=71, specificity=68) and healthy individuals (p=0.01, sensitivity=71, specificity=61). Patients with an episodic course could not be distinguished from healthy individuals. When patients with an intermediate outcome were classified according to the discriminating pattern episodic versus continuous, 74% of those who did not develop other episodes were classified as episodic, and 65% of those who did develop further episodes were classified as continuous (p=0.035). CONCLUSIONS: We provide preliminary evidence of MRI application in the individualized prediction of future illness course, using a simple and automated SVM pipeline. When replicated and validated in larger groups, this could enable targeted clinical decisions based on imaging data.
Assessment of muscle mass using ultrasound with minimal versus maximal pressure compared with computed tomography in critically ill adult patients.
(Elsevier BV, 2020-11-24)
BACKGROUND: Preserved skeletal muscle mass identified using computed tomography (CT) predicts improved outcomes from critical illness; however, CT imaging have few limitations such that it involves a radiation dose and transferring patients out of the intensive care unit. This study aimed to assess in critically ill patients the relationship between muscle mass estimates obtained using minimally invasive ultrasound techniques with both minimal and maximal pressure compared with CT images at the third lumber vertebra level. METHODS: All patients were treated in a single Australian intensive care unit. Eligible patients had paired assessments, within a 72-h window, of muscle mass by ultrasound (quadriceps muscle layer thickness in centimetres, with maximal and minimal pressure) and CT axial cross-sectional area (cm2). Data are presented as mean (standard deviation), median (interquartile range), and frequencies [n (%)]. RESULTS: Thirty-five patients [mean (standard deviation) age = 55 (16) years, median (interquartile range) body mass index = 27 (25-32) kg/m2, and 26 (74%) men] contributed 41 paired measurements. Quadriceps muscle thickness measured using the maximal pressure technique was a strong independent predictor of lumbar muscle cross-sectional area. Within a multivariate mixed linear regression model and adjusting for sex, age, and body mass index, for every 1 cm increase in quadriceps muscle layer thickness, the lumbar muscle cross-sectional area increased by 35 cm2 (95% confidence interval = 11-59 cm2). Similar univariate associations were observed using minimal pressure; however, as per multivariate analysis, there was no strength in this relationship [8 cm2 (95% confidence interval = -5 to 22 cm2)]. CONCLUSION: Ultrasound assessment of the quadriceps muscle using maximal pressure reasonably predicts the skeletal muscle at the third lumbar vertebra level of critically ill patients. However, there is substantial uncertainty within these regression estimates, and this may reduce the current utility of this technique as a minimally invasive surrogate for CT assessment of skeletal muscle mass.
Lymph node yield in node-negative patients predicts cancer specific survival following radical cystectomy for transitional cell carcinoma
(KOREAN UROLOGICAL ASSOC, 2017-11-01)
Purpose: To determine the oncological implications of increased nodal dissection in node-negative bladder cancer during radical cystectomy in a contemporary Australian series. Materials and Methods: We performed a multicenter retrospective study, including more than 40 surgeons across 5 sites over a 10-year period. We identified 353 patients with primary bladder cancer undergoing radical cystectomy. Extent of lymphadenectomy was defined as follows; limited pelvic lymph node dissection (PLND) (perivesical, pelvic, and obturator), standard PLND (internal and external iliac) and extended PLND (common iliac). Multivariable cox proportional hazards and logistic regression models were used to determine LNY effect on cancer-specific survival. Results: Over the study period, the extent of dissection and lymph node yield increased considerably. In node-negative patients, lymph node yield (LNY) conferred a significantly improved cancer-specific survival. Compared to cases where LNY of 1 to 5 nodes were taken, the hazard ratio (HR) for 6 to 15 nodes harvested was 0.78 (95% confidence interval [CI], 0.43-1.39) and for greater than 15 nodes the HR was 0.31 (95% CI, 0.17-0.57), adjusted for age, sex, T stage, margin status, and year of surgery. The predicted probability of cancer-specific death within 2 years of cystectomy was 16% (95% CI, 13%-19%) with 10 nodes harvested, falling to 5.5% (95% CI, 0%-12%) with 30 nodes taken. Increasing harvest in all PLND templates conferred a survival benefit. Conclusions: The findings of the current study highlight the improved oncological outcomes with increased LNY, irrespective of the dissection template. Further prospective research is needed to aid LND data interpretation.