Three-dimensional myocardial strains in seven isolated, potassium-arrested dog hearts were measured by biplane radiography of 3 transmural columns of 4-6 radiopaque beads implanted in the midanterior left ventricular free wall. Transmural distributions of strain during inflation of a left ventricular balloon to 20-30 mmHg were computed with respect to the zero pressure state. Magnitudes of the 3 principal strains increased in proportion to ventricular volume (0.0088, 0.0037, and -0.0059 ml-1). At a left ventricular pressure of 8 +/- 4 mmHg, mean circumferential (E11) and longitudinal strains (E22) were similar, increasing from epicardium (0.058 +/- 0.055 and 0.036 +/- 0.024) to subendocardium (0.139 +/- 0.102 and 0.120 +/- 0.084) as did the transmural (wall thinning) strain E33 (-0.053 +/- 0.071 to -0.128 +/- 0.083). Negative in-plane shear E12 was small (-0.008 to -0.052), consistent with a left-handed torsion of the left ventricular wall. Mean transverse shear strains E13 and E23 were small (-0.029 to 0.007) but showed considerable variability between hearts. Fiber strain had no significant transmural variation (P = 0.57). The principal axis of greatest strain was close to the fiber orientation on the epicardium (-15 degrees) but closer to the cross-fiber direction near the endocardium (-40 degrees). Therefore, the end-diastolic fiber lengths are maximized on the epicardium and minimized on the endocardium.

OBJECTIVETo determine the microbiological profile of diabetes-related foot infections (DRFIs) and the impact of wound duration, inpatient treatment, and chronic kidney disease (CKD).RESEARCH DESIGN AND METHODSPostdebridement microbiological samples were collected from individuals presenting with DRFIs from 1 January 2005 to 31 December 2007.RESULTSA total of 653 specimens were collected from 379 individuals with 36% identifying only one isolate. Of the total isolates, 77% were gram-positive bacteria (staphylococci 43%, streptococci 13%). Methicillin-resistant Staphylococcus aureus (MRSA) was isolated from 23%; risk factors for MRSA included prolonged wound duration (odds ratio 2.31), inpatient management (2.19), and CKD (OR 1.49). Gram-negative infections were more prevalent with inpatient management (P = 0.002) and prolonged wound duration (P < 0.001). Pseudomonal isolates were more common in chronic wounds (P < 0.001).CONCLUSIONSDRFIs are predominantly due to gram-positive aerobes but are usually polymicrobial and increase in complexity with inpatient care and ulcer duration. In the presence of prolonged duration, inpatient management, or CKD, empiric MRSA antibiotic cover should be considered.

BackgroundDisinvestment (removal, reduction, or reallocation) of routinely provided health services can be difficult when there is little published evidence examining whether the services are effective or not. Evidence is required to understand if removing these services produces outcomes that are inferior to keeping such services in place. However, organisational imperatives, such as budget cuts, may force healthcare providers to disinvest from these services before the required evidence becomes available. There are presently no experimental studies examining the effectiveness of allied health services (e.g., physical therapy, occupational therapy, and social work) provided on weekends across acute medical and surgical hospital wards, despite these services being routinely provided internationally. The aim of this study was to understand the impact of removing weekend allied health services from acute medical and surgical wards using a disinvestment-specific non-inferiority research design.Methods and findingsWe conducted 2 stepped-wedge cluster randomised controlled trials between 1 February 2014 and 30 April 2015 among patients on 12 acute medical or surgical hospital wards spread across 2 hospitals. The hospitals involved were 2 metropolitan teaching hospitals in Melbourne, Australia. Data from n = 14,834 patients were collected for inclusion in Trial 1, and n = 12,674 in Trial 2. Trial 1 was a disinvestment-specific non-inferiority stepped-wedge trial where the ‘current’ weekend allied health service was incrementally removed from participating wards each calendar month, in a random order, while Trial 2 used a conventional non-inferiority stepped-wedge design, where a ‘newly developed’ service was incrementally reinstated on the same wards as in Trial 1. Primary outcome measures were patient length of stay (proportion staying longer than expected and mean length of stay), the proportion of patients experiencing any adverse event, and the proportion with an unplanned readmission within 28 days of discharge. The ‘no weekend allied health service’ condition was considered to be not inferior if the 95% CIs of the differences between this condition and the condition with weekend allied health service delivery were below a 2% increase in the proportion of patients who stayed in hospital longer than expected, a 2% increase in the proportion who had an unplanned readmission within 28 days, a 2% increase in the proportion who had any adverse event, and a 1-day increase in the mean length of stay. The current weekend allied health service included physical therapy, occupational therapy, speech therapy, dietetics, social work, and allied health assistant services in line with usual care at the participating sites. The newly developed weekend allied health service allowed managers at each site to reprioritise tasks being performed and the balance of hours provided by each professional group and on which days they were provided. Analyses conducted on an intention-to-treat basis demonstrated that there was no estimated ef...

BackgroundDisinvestment from inefficient or ineffective health services is a growing priority for health care systems. Provision of allied health services over the weekend is now commonplace despite a relative paucity of evidence supporting their provision. The relatively high cost of providing this service combined with the paucity of evidence supporting its provision makes this a potential candidate for disinvestment so that resources consumed can be used in other areas.This study aims to determine the effectiveness, cost-effectiveness and safety of the current model of weekend allied health service and a new stakeholder-driven model of weekend allied health service delivery on acute medical and surgical wards compared to having no weekend allied health service.Methods/DesignTwo stepped wedge, cluster randomised trials of weekend allied health services will be conducted in six acute medical/surgical wards across two public metropolitan hospitals in Melbourne (Australia). Wards have been chosen to participate by management teams at each hospital. The allied health services to be investigated will include physiotherapy, occupational therapy, speech therapy, dietetics, social work and allied health assistants. At baseline, all wards will be receiving weekend allied health services. Study 1 intervention will be the sequential disinvestment (roll-in) of the current weekend allied health service model from each participating ward in monthly intervals and study 2 will be the roll-out of a new stakeholder-driven model of weekend allied health service delivery. The order in which weekend allied health services will be rolled in and out amongst participating wards will be determined randomly. This trial will be conducted in each of the two participating hospitals at a different time interval. Primary outcomes will be length of stay, rate of unplanned hospital readmission within 28 days and rate of adverse events. Secondary outcomes will be number of complaints and compliments, staff absenteeism, and patient discharge destination, satisfaction, and functional independence at discharge.DiscussionThis is the world’s first application of the recently described non-inferiority (roll-in) stepped wedge trial design, and the largest investigation of the effectiveness of weekend allied health services on acute medical surgical wards to date.Trial registrationAustralian New Zealand Clinical Trials Registry.Registration number: ACTRN12613001231730 (first study) and ACTRN12613001361796 (second study).Was this trial prospectively registered?: Yes.Date registered: 8 November 2013 (first study), 12 December 2013 (second study).Anticipated completion: June 2015.Protocol version: 1.Role of trial sponsor: KP and DL are directly employed by one of the trial sponsors, their roles were: KP assisted with overall development of research design and assisted with overall project management; DL contributed to project management, administration and communications strategy.Electronic supplementary materialThe online version of this article (doi:10....