Determination of independent risk factors for early healthcare-associated infections acquired after acute stroke admission: A multi-centre registry-based cohort study

OBJECTIVE

Healthcare-associated infections (HCAIs) in patients admitted with acute conditions pose a serious risk to patients and a major challenge to healthcare services. However, there is a lack of consistency in reporting aetiological risk factors, particularly in acute stroke patients. Here, we determined independent risk factors of two common HCAIs (urinary tract infection and pneumonia) acquired within 7-days of admission after an acute stroke.

METHODS

Data were prospectively collected (2014-2016) from the Sentinel Stroke National Audit Programme for 3,309 patients (mean age=76.2yr, SD=13.5) admitted to four UK hyperacute stroke units. Associations between variables were assessed by forward stepwise multivariable logistic regression (odds ratios, 95 % confidence intervals).

RESULTS

The rate of urinary tract infection and/or pneumonia occurring within 7-days of admission was 15.0 %. The risk of urinary tract infection and/or pneumonia was increased amongst women: OR = 1.35 (1.08-1.68); patients from ethnic minority backgrounds: OR = 1.77 (1.01-3.10); patients aged 70-79 years: OR = 2.08 (1.42-3.06), and ≥80 years: OR = 3.20 (2.26-4.55); history of hypertension: OR = 1.59 (1.27-1.98); history of atrial fibrillation: OR = 1.67 (1.32-2.12); pre-stroke disability: OR = 2.08 (1.44-3.00); intracranial haemorrhage: OR = 1.41 (1.07-1.86); severe stroke: OR = 3.21 (2.32-4.45); swallow screening within 4-72 h: OR = 1.42 (1.08-1.86); swallow screening beyond 72 h: OR = 1.70 (1.08-2.70). History of congestive heart failure, diabetes and previous stroke did not significantly associate with HCAIs.

CONCLUSIONS

A profile of independent risk factors for two common HCAIs in acute stroke was identified. These findings provide valuable information for timely intervention to reduce HCAIs, and the ability to minimise subsequent adverse outcomes.

Establishing Reference Values for Temporal Kinematic Swallow Events Across the Lifespan in Healthy Community Dwelling Adults Using High-Resolution Cervical Auscultation

Few research studies have investigated temporal kinematic swallow events in healthy adults to establish normative reference values. Determining cutoffs for normal and disordered swallowing is vital for differentially diagnosing presbyphagia, variants of normal swallowing, and dysphagia; and for ensuring that different swallowing research laboratories produce consistent results in common measurements from different samples within the same population. High-resolution cervical auscultation (HRCA), a sensor-based dysphagia screening method, has accurately annotated temporal kinematic swallow events in patients with dysphagia, but hasn't been used to annotate temporal kinematic swallow events in healthy adults to establish dysphagia screening cutoffs. This study aimed to determine: (1) Reference values for temporal kinematic swallow events, (2) Whether HRCA can annotate temporal kinematic swallow events in healthy adults. We hypothesized (1) Our reference values would align with a prior study; (2) HRCA would detect temporal kinematic swallow events as accurately as human judges. Trained judges completed temporal kinematic measurements on 659 swallows (N = 70 adults). Swallow reaction time and LVC duration weren't different (p > 0.05) from a previously published historical cohort (114 swallows, N = 38 adults), while other temporal kinematic measurements were different (p < 0.05), suggesting a need for further standardization to feasibly pool data analyses across laboratories. HRCA signal features were used as input to machine learning algorithms and annotated UES opening (69.96% accuracy), UES closure (64.52% accuracy), LVC (52.56% accuracy), and LV re-opening (69.97% accuracy); providing preliminary evidence that HRCA can noninvasively and accurately annotate temporal kinematic measurements in healthy adults to determine dysphagia screening cutoffs.

How Closely do Machine Ratings of Duration of UES Opening During Videofluoroscopy Approximate Clinician Ratings Using Temporal Kinematic Analyses and the MBSImP?

Clinicians evaluate swallow kinematic events by analyzing videofluoroscopy (VF) images for dysphagia management. The duration of upper esophageal sphincter opening (DUESO) is one important temporal swallow event, because reduced DUESO can result in pharyngeal residue and penetration/aspiration. VF is frequently used for evaluating swallowing but exposes patients to radiation and is not always feasible/readily available. High resolution cervical auscultation (HRCA) is a non-invasive, sensor-based dysphagia screening method that uses signal processing and machine learning to characterize swallowing. We investigated HRCA's ability to annotate DUESO and predict Modified Barium Swallow Impairment Profile (MBSImP) scores (component #14). We hypothesized that HRCA and machine learning techniques would detect DUESO with similar accuracy as human judges. Trained judges completed temporal kinematic measurements of DUESO on 719 swallows (116 patients) and 50 swallows (15 age-matched healthy adults). An MBSImP certified clinician completed MBSImP ratings on 100 swallows. A multi-layer convolutional recurrent neural network (CRNN) using HRCA signal features for input was used to detect DUESO. Generalized estimating equations models were used to determine statistically significant HRCA signal features for predicting DUESO MBSImP scores. A support vector machine (SVM) classifier and a leave-one-out procedure was used to predict DUESO MBSImP scores. The CRNN detected UES opening within a 3-frame tolerance for 82.6% of patient and 86% of healthy swallows and UES closure for 72.3% of patient and 64% of healthy swallows. The SVM classifier predicted DUESO MBSImP scores with 85.7% accuracy. This study provides evidence of HRCA's feasibility in detecting DUESO without VF images.

A Preliminary Investigation of Whether HRCA Signals Can Differentiate Between Swallows from Healthy People and Swallows from People with Neurodegenerative Diseases

High-resolution cervical auscultation (HRCA) is an emerging method for non-invasively assessing swallowing by using acoustic signals from a contact microphone, vibratory signals from an accelerometer, and advanced signal processing and machine learning techniques. HRCA has differentiated between safe and unsafe swallows, predicted components of the Modified Barium Swallow Impairment Profile, and predicted kinematic events of swallowing such as hyoid bone displacement, laryngeal vestibular closure, and upper esophageal sphincter opening with a high degree of accuracy. However, HRCA has not been used to characterize swallow function in specific patient populations. This study investigated the ability of HRCA to differentiate between swallows from healthy people and people with neurodegenerative diseases. We hypothesized that HRCA would differentiate between swallows from healthy people and people with neurodegenerative diseases with a high degree of accuracy. We analyzed 170 swallows from 20 patients with neurodegenerative diseases and 170 swallows from 51 healthy age-matched adults who underwent concurrent video fluoroscopy with non-invasive neck sensors. We used a linear mixed model and several supervised machine learning classifiers that use HRCA signal features and a leave-one-out procedure to differentiate between swallows. Twenty-two HRCA signal features were statistically significant (p < 0.05) for predicting whether swallows were from healthy people or from patients with neurodegenerative diseases. Using the HRCA signal features alone, logistic regression and decision trees classified swallows between the two groups with 99% accuracy, 100% sensitivity, and 99% specificity. This provides preliminary research evidence that HRCA can differentiate swallow function between healthy and patient populations.

Tracking Hyoid Bone Displacement During Swallowing Without Videofluoroscopy Using Machine Learning of Vibratory Signals

Identifying physiological impairments of swallowing is essential for determining accurate diagnosis and appropriate treatment for patients with dysphagia. The hyoid bone is an anatomical landmark commonly monitored during analysis of videofluoroscopic swallow studies (VFSSs). Its displacement is predictive of penetration/aspiration and is associated with other swallow kinematic events. However, VFSSs are not always readily available/feasible and expose patients to radiation. High-resolution cervical auscultation (HRCA), which uses acoustic and vibratory signals from a microphone and tri-axial accelerometer, is under investigation as a non-invasive dysphagia screening method and potential adjunct to VFSS when it is unavailable or not feasible. We investigated the ability of HRCA to independently track hyoid bone displacement during swallowing with similar accuracy to VFSS, by analyzing vibratory signals from a tri-axial accelerometer using machine learning techniques. We hypothesized HRCA would track hyoid bone displacement with a high degree of accuracy compared to humans. Trained judges completed frame-by-frame analysis of hyoid bone displacement on 400 swallows from 114 patients and 48 swallows from 16 age-matched healthy adults. Extracted features from vibratory signals were used to train the predictive algorithm to generate a bounding box surrounding the hyoid body on each frame. A metric of relative overlapped percentage (ROP) compared human and machine ratings. The mean ROP for all swallows analyzed was 50.75%, indicating > 50% of the bounding box containing the hyoid bone was accurately predicted in every frame. This provides evidence of the feasibility of accurate, automated hyoid bone displacement tracking using HRCA signals without use of VFSS images.

Impact of the systematic use of the volume-viscosity swallow test in patients with acute ischaemic stroke: a retrospective study

Background

Dysphagia is common after stroke. Patients with dysphagia have a higher risk of stroke-associated pneumonia (SAP) and poor outcomes. Early detection of dysphagia is necessary to identify and manage patients at high risk of aspiration. The aim of the study was to assess the impact of the systematic administration of the volume-viscosity swallow test (V-VST) in patients with acute ischaemic stroke.

Methods

This was a retrospective observational study that enrolled patients with acute ischaemic stroke in two consecutive time periods: pre-V-VST, when the 30-mL water-swallowing test (WST) was systematically administered, and V-VST, when all patients underwent the WST and the V-VST test was systematically administered if the patient failed the WST.

Results

Two hundred and 42 patients were enrolled. The mean age of the participants was 68.8 ± 10.88 years, 61.2% were male, and the median National Institutes of Health Stroke Scale score was 3 (IQR, 1–6). A total of 147 patients were enrolled during the pre-V-VST period and 95 were enrolled during the V-VST period. There was a significant difference in the occurrence of SAP (21.8% vs. 10.5%, p = 0.024) and the rate of nasogastric tube feeding (25.9% vs. 14.7%, p = 0.040) between the two groups, and no differences were found in the length of hospital stay (p = 0.277) or the total cost of hospitalization (p = 0.846).

Conclusions

The V-VST was a better clinical screening tool, and it can also provide detailed suggestions regarding dietary modifications to prevent aspiration and SAP.

Oropharyngeal Dysphagia Evaluation Tools in Adults with Solid Malignancies Outside the Head and Neck and Upper GI Tract: A Systematic Review

Dysphagia is often associated with head and neck and upper gastrointestinal (GI) tract cancers. Evidence suggests that those with solid malignancies in other primary sites may also have swallowing difficulties. Timely and accurate identification of dysphagia is important given the impact it has on hydration, medical treatment, nutrition, prognosis, and quality of life. A systematic review was conducted to identify swallow screening, evaluation, and quality of life tools for those with solid malignancies outside the head and neck and upper GI tract. Ten electronic databases, one journal and two published conference proceedings were searched. Following deduplication, 7435 studies were examined for relevance. No tools were validated solely in this cancer population, though some included this group in larger cohorts. Comments are provided on the diagnostic properties and applicability of these tools. In the absence of appropriate diagnostic instruments, the exact prevalence of dysphagia and its impact on clinical and psychosocial well-being remain unknown. Accurate and adequate measurement of therapeutic intervention is also compromised. This review establishes the need for validated dysphagia evaluation tools for this clinical population.

Dysphagia screening after acute stroke: a quality improvement project using criteria-based clinical audit

BACKGROUND

Dysphagia is common after stroke and represents a major risk factor for developing aspiration pneumonia. Early detection can reduce the risk of pulmonary complications and death. Despite the fact that evidence-based guidelines recommend screening for swallowing deficit using a standardized screening tool, national audits has identified a gap between practice and this recommendation. The aim was to determine the level of adherence to an evidence-based recommendation on swallow assessment and to take actions to improve practice if necessary.

METHODS

We carried out a criteria-based clinical audit (CBCA) in a small stroke unit at a Norwegian hospital. Patients with hemorrhagic stroke, ischemic stroke and transient ischemic attack were included. A power calculation informed the number of included patients at baseline (n = 80) and at re-audit (n = 35). We compared the baseline result with the evidence-based criteria and gave feedback to management and staff. A brainstorming session, a root-cause analysis and implementation science were used to inform the quality improvement actions which consisted of workshops, use of local opinion leaders, manual paper reminders and feedback. We completed a re-audit after implementation. Percentages and median are reported with 95% confidence intervals (CI).

RESULTS

Among 88 cases at baseline, documentation of swallow screening was complete for 6% (95% CI 2-11). In the re-audit (n = 51) 61% (95% CI 45-74) had a complete screening.

CONCLUSION

A CBCA involving management and staff, and using multiple tailored intervention targeting barriers, led to greater adherence with the recommendation for screening stroke patients for dysphagia.