Hospital discharge in patients at risk of surgical site infection: antimicrobial stewardship at Ferrara University Hospital, Italy

INTRODUCTION

The appropriate use of antibiotics is a global priority in order to avoid antibiotic resistance. Up to 50% of antibiotics usage in hospital is inappropriate (e.g. prolonged surgical prophylaxis, "defensive medicine" approach). In 2015, at the Ferrara University Hospital, an antimicrobial stewardship intervention to reduce antimicrobial prescription at the time of hospital discharge in patients at risk of surgical site infection was implemented. This programme included: update meetings for health professionals, focused meetings for critical wards, reviews of some surgical prophylaxis protocols, recommendations to reduce broad-spectrum antimicrobials use, and planning of an audit. The purpose of this study has been to evaluate the effect of this antimicrobial stewardship programme.

METHODS

To evaluate the effect of this intervention, a study has been carried out including inpatients in surveillance for surgical site infection who had surgery during the last quarter of 2014 (pre-intervention group; 461 patients) and of 2015 (post-intervention group; 532 patients).

RESULTS

The proportion of patients with prescription of at least one antimicrobial at discharge decreased from 33% to 24.4% (p = 0.002). The most prescribed categories of antimicrobials in both groups were the combination of penicillins with beta-lactamase inhibitors (with prescription rate reduced from 21.9% to 18%; p = 0.13) and fluoroquinolones (from 8.2% to 3.2%; p < 0.001).

CONCLUSIONS

This statistically significant reduction in antimicrobial prescription after the intervention was registered without a change in surgical site infections rate (from 3.5% to 3.2%; p = 0.08). Therefore, this intervention was effective in reducing the antimicrobial prescription at discharge, without affecting patients' safety.

Temporal trends of healthcare associated infections and antimicrobial use in 2011-2013, observed with annual point prevalence surveys in Ferrara University Hospital, Italy

INTRODUCTION

Healthcare associated infections (HAIs) and misuse of antimicrobials (AMs) represent a growing public health problem. The Point Prevalence Surveys (PPSs) find available information to be used for specific targeted interventions and evaluate their effects. The objective of this study was to estimate the prevalence of HAIs and AM use, to describe types of infections, causative pathogens and to compare data collected through three PPSs in Ferrara University Hospital (FUH), repeated in 3 different years (2011-2013). The population-based sample consists of all patients admitted to every acute care and rehabilitation Department in a single day.

METHODS

ECDC Protocol and Form for PPS of HAI and AM use, Version 4.2, July 2011. Risk factor analysis was performed using logistic regression.

RESULTS

1,239 patients were observed. Overall, HAI prevalence was 9.6%; prevalence was higher in Intensive Care Units; urinary tract infections were the most common HAIs in all 3 surveys; E.coli was the most common pathogen; AM use prevalence was 51.1%; AMs most frequently administered were fluoroquinolones, combinations of penicillins and third-generation cephalosporins. According to the regression model, urinary catheter (OR: 2.5) and invasive respiratory device (OR: 2.3) are significantly associated risk factors for HAIs (p < 0.05).

CONCLUSIONS

PPSs are a sensitive and effective method of analysis. Yearly repetition is a useful way to maintain focus on the topic of HAIs and AM use, highlighting how changes in practices impact on the outcome of care and providing useful information to implement intervention programs targeted on specific issues.

Using postural synergies to animate a low-dimensional hand avatar in haptic simulation

A technique to animate a realistic hand avatar with 20 DoFs based on the biomechanics of the human hand is presented. The animation does not use any sensor glove or advanced tracker with markers. The proposed approach is based on the knowledge of a set of kinematic constraints on the model of the hand, referred to as postural synergies, which allows to represent the hand posture using a number of variables lower than the number of joints of the hand model. This low-dimensional set of parameters is estimated from direct measurement of the motion of thumb and index finger tracked using two haptic devices. A kinematic inversion algorithm has been developed, which takes synergies into account and estimates the kinematic configuration of the whole hand, i.e., also of the fingers whose end tips are not directly tracked by the two haptic devices. The hand skin is deformable and its deformation is computed using a linear vertex blending technique. The proposed synergy-based animation of the hand avatar involves only algebraic computations and is suitable for real-time implementation as required in haptics.

Force feedback in a piezoelectric linear actuator for neurosurgery

BACKGROUND

Force feedback in robotic minimally invasive surgery allows the human operator to manipulate tissues as if his/her hands were in contact with the patient organs. A force sensor mounted on the probe raises problems with sterilization of the overall surgical tool. Also, the use of off-axis gauges introduces a moment that increases the friction force on the bearing, which can easily mask off the signal, given the small force to be measured.

METHODS

This work aims at designing and testing two methods for estimating the resistance to the advancement (force) experienced by a standard probe for brain biopsies within a brain-like material. The further goal is to provide a neurosurgeon using a master-slave tele-operated driver with direct feedback on the tissue mechanical characteristics. Two possible sensing methods, in-axis strain gauge force sensor and position-position error (control-based method), were implemented and tested, both aimed at device miniaturization. The analysis carried out was aimed at fulfilment of the psychophysics requirements for force detection and delay tolerance, also taking into account safety, which is directly related to the last two issues. Controller parameters definition is addressed and consideration is given to development of the device with integration of a haptic interface.

RESULTS

Results show better performance of the control-based method (RMSE < 0.1 N), which is also best for reliability, sterilizability, and material dimensions for the application addressed.

CONCLUSIONS

The control-based method developed for force estimation is compatible with the neurosurgical application and is also capable of measuring tissue resistance without any additional sensors. Force feedback in minimally invasive surgery allows the human operator to manipulate tissues as if his/her hands were in contact with the patient organs.