Measurement of Oxygen Desaturation Is Not Useful for the Detection of Aspiration in Dysphagic Stroke Patients

Comparative analysis of videofluoroscopy and pulse oximetry for aspiration identification in patients with dysphagia after stroke and non-dysphagics

PURPOSE

Dysphagia is a prevalent symptom observed in acute stroke. Several bedside screening tests are employed for the early detection of dysphagia. Pulse oximetry emerges as a practical and supportive method to augment the existing techniques utilized during bedside swallowing assessments. Desaturation levels, as measured by pulse oximetry, are acknowledged as indicative of aspiration by certain screening tests. However, the predictive capability of pulse oximetry in determining aspiration remains a subject of controversy. The objective of this study was to compare aspiration and oxygen desaturation levels by time and aspiration severity in dysphagic patients compared to healthy controls. It also aimed to evaluate the accuracy of pulse oximetry by comparing it with VFSS findings in detecting aspiration in both liquid (IDDSI-0) and semi-solid (IDDSI-4) consistencies.

MATERIALS AND METHODS

Eighty subjects (40 healthy and 40 acute stroke patients) participated. Patients suspected of dysphagia underwent videofluoroscopy as part of the stroke unit's routine procedure. Baseline SpO2 was measured before VFSS, and stabilized values were recorded. Sequential IDDSI-0 and IDDSI-4 barium tests were conducted with 5 ml boluses. Stabilized SPO2 values were recorded during swallowing and 3-min post-feeding. Patients with non-dysphagia received equal bolus monitoring. Changes in SPO2 during, before, and after swallowing were analyzed for each consistency in both groups.

RESULTS

The study revealed a statistically significant difference in SPO2 between patients with dysphagia and controls for IDDSI-4 and IDSSI-0. In IDDSI-4, 20% of patients experienced SpO2 decrease compared to 2.5% in control group (p = 0.013). For IDDSI-0, 35% of patients showed SpO2 decrease, while none in the control group did (p = 0.0001). Aspiration rates were 2.5% in IDDSI-4 and 57.5% in IDDSI-0. In IDDSI-0, SpO2 decrease significantly correlated with aspiration (p = 0.0001). In IDDSI-4, 20.5% had SpO2 decrease without aspiration, and showing no significant difference (p = 0.613). Penetration-Aspiration Scale scores had no significant association with SpO2 decrease (p = 0.602). Pulse oximetry in IDDSI-4 had limited sensitivity (0%) and positive predictive value, (0%) while in IDDSI-0, it demonstrated acceptable sensitivity (60.9%) and specificity (100%) with good discrimination capability (AUC = 0.83).

CONCLUSIONS

A decrease in SPO2 may indicate potential aspiration but is insufficient alone for detection. This study proposes pulse oximetry as a valuable complementary tool in assessing dysphagia but emphasizes that aspiration cannot be reliably predicted based solely on SpO2 decrease.

Contribution of Wireless Wi-Fi Intraoral Cameras to the Assessment of Swallowing Safety and Efficiency

BACKGROUND

Clinical evaluation of swallowing provides important clinical information but is limited in detecting penetration, aspiration, and pharyngeal residue in patients with suspected dysphagia. Although this is an old problem, there remains limited access to low-cost methods to evaluate swallowing safety and efficiency.

PURPOSE

The purpose of this technical report is to describe the experience of a single center that recently began using a wireless Wi-Fi intraoral camera for transoral endoscopic procedures as an adjunct to clinical swallowing evaluation. We describe the theoretical structure of this new clinical evaluation proposal. We present descriptive findings on its diagnostic performance in relation to videofluoroscopic swallowing study as the gold standard in a cohort of seven patients with dysphagia following head and neck cancer. We provide quantitative data on intra- and interrater reliability. Furthermore, this report discusses how this technology can be applied in the clinical practice of professionals who treat patients with dysphagia and provides directions for future research.

CONCLUSIONS

This preliminary retrospective study suggests that intraoral cameras can reveal the accumulated oropharyngeal secretions and postswallow pharyngolaryngeal residue in patients with suspected dysphagia. Future large-scale studies focusing on validating and exploring this contemporary low-cost technology as part of a clinical swallowing evaluation are warranted.

Risk factors for dysphagia in patients with acute and chronic ischemic stroke: A retrospective cohort study

Background

Dysphagia is a common and clinically significant complication of ischemic stroke. The prevalence and risk factors for dysphagia may vary at different stages following an ischemic stroke.

Methods

This study included patients with acute and chronic ischemic stroke who were treated at the Department of Rehabilitation, First Affiliated Hospital, Zhejiang University School of Medicine from 2019 to 2022. Various demographic, clinical, and laboratory parameters were collected, and statistical analyses were performed to investigate their association with dysphagia.

Results

Among the 399 ischemic stroke patients included in the study, 165 (41.4 %) experienced dysphagia, with 72 (38.7 %) in the acute phase and 93 (43.7 %) in the chronic phase. Univariate analysis revealed significant associations (p < 0.05) between dysphagia and factors such as pulmonary infection, aphasia, NIHSS score, ADL score, NLR score, lower extremity Brunnstrom's stages, and sit-to-stand balance. Multiple logistic regression analysis, after adjusting for confounding factors, identified the ADL score as an independent predictor of dysphagia. These findings were consistent across three time-windows: the acute phase, the chronic phase, and 180 days after stroke onset. Additionally, the lymphocyte count and pulmonary infection were identified as potential independent indicators.

Conclusions

This study investigated the prevalence and risk factors for dysphagia in ischemic stroke patients at different time-windows. A low ADL score (<40) may serve as a valuable and reliable predictor for poststroke dysphagia in clinical settings.

Accuracy of Dysphagia Standard Assessment (DSA®) bedside screening test: a flowchart for patient eligibility

Background

Oropharyngeal dysphagia (OD) screening tests have improved patient management; however, the complex applicability and high percentage of false negatives do not allow these tests to be considered completely reliable if not supported by an instrumental investigation. The aim of the present study is to evaluate an OD screening test, the Dysphagia Standard Assessment (DSA®) with different volumes and viscosities.

Materials and methods

Prospective study of 72 patients evaluated for suspected OD through a double-blind methodology conducted by two operators. All patients underwent fiberoptic endoscopic evaluation of swallowing (FEES) as a reference test and a separate DSA® test. DSA® was performed by administering boluses with different viscosities, with the signal of interruption of the test being: onset of the cough reflex, wet voice after swallowing, and/or desaturation of O2 ≥ 5%. The Penetration-Aspiration Scale (PAS) was evaluated by FEES. The cut-off identified to diagnose OD was PAS ≥ 3.

Results

The test showed an accuracy of 82%, a sensitivity of 0.93 (95% C.I. 0.84–0.97), and a specificity of 0.78 (95% C.I. 0.67–0.87); positive predictive value 0.55 (95% C.I. 0.43–0.67); negative predictive value 0.97 (95% C.I. 0.90–0.99), positive likelihood ratio 4.37 (95% C.I. 3.6–5.2); likelihood negative ratio 0.08 (95% C.I. 0.06–0.09).

Conclusions

According to the preliminary results, the test showed good outcomes in determining the presence or absence of OD with a wide spectrum of applicability with some limitations that could be overcome by the selection of a target population. For this reason, a flowchart to address patient eligibility was developed.

Diagnosis and treatment of neurogenic dysphagia - S1 guideline of the German Society of Neurology

Introduction

Neurogenic dysphagia defines swallowing disorders caused by diseases of the central and peripheral nervous system, neuromuscular transmission, or muscles. Neurogenic dysphagia is one of the most common and at the same time most dangerous symptoms of many neurological diseases. Its most important sequelae include aspiration pneumonia, malnutrition and dehydration, and affected patients more often require long-term care and are exposed to an increased mortality. Based on a systematic pubmed research of related original papers, review articles, international guidelines and surveys about the diagnostics and treatment of neurogenic dysphagia, a consensus process was initiated, which included dysphagia experts from 27 medical societies.

Recommendations

This guideline consists of 53 recommendations covering in its first part the whole diagnostic spectrum from the dysphagia specific medical history, initial dysphagia screening and clinical assessment, to more refined instrumental procedures, such as flexible endoscopic evaluation of swallowing, the videofluoroscopic swallowing study and high-resolution manometry. In addition, specific clinical scenarios are captured, among others the management of patients with nasogastric and tracheotomy tubes. The second part of this guideline is dedicated to the treatment of neurogenic dysphagia. Apart from dietary interventions and behavioral swallowing treatment, interventions to improve oral hygiene, pharmacological treatment options, different modalities of neurostimulation as well as minimally invasive and surgical therapies are dealt with.

Conclusions

The diagnosis and treatment of neurogenic dysphagia is challenging and requires a joined effort of different medical professions. While the evidence supporting the implementation of dysphagia screening is rather convincing, further trials are needed to improve the quality of evidence for more refined methods of dysphagia diagnostics and, in particular, the different treatment options of neurogenic dysphagia. The present article is an abridged and translated version of the guideline recently published online (https://www.awmf.org/uploads/tx_szleitlinien/030-111l_Neurogene-Dysphagie_2020-05.pdf).

Protocols and assessment procedures in fiberoptic endoscopic evaluation of swallowing: an updated systematic review

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Assessments of neurological populations do not demonstrate standardization in swallowing videoendoscopy.

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Need for standardization of VED protocols for patient diagnosis and management.

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None of the studies used the same protocol.

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The quality of the studies varied widely mainly in their methodologies and protocols.

Introduction

Neurological alterations can generate swallowing disorders and fiberoptic endoscopic evaluation of swallowing is one of the tests performed for its diagnosis, as well as assistance in dysphagia management.

Objective

To identify and describe a fiberoptic endoscopic evaluation of swallowing standardized protocol for the neurological adult population and its stages.

Methods

Systematic review registered on the PROSPERO platform (CRD42018069428), carried out on the websites: MEDLINE, Cochrane Library and Scielo; published between 2009 and 2020. Randomized clinical trials, cross-sectional, and longitudinal studies were included. Two independent judges evaluated the study design and extracted the data from the selected studies. Doubts regarding inclusion or not of the studies were evaluated by a third judge. Scientific articles included were those with adult neurological remained patients with outcomes: (1) diagnosis of swallowing disorder (2) change in sensitivity in laryngeal region (3) penetration of food offered (4) aspiration of food offered.

Results

3724 articles were initially selected, after personalized search for patients with neurological alterations 101 studies remained. In the end, 21 qualitative studies from 2009 to 2020 remained in the systematic review and they were described in detail and compared. Seven articles used protocols of the institutions in which the research took place and four mentioned using the same protocol. The reliable reproducibility of the protocols is feasible only in three of the articles, even presenting different protocols.

Conclusion

There is no standard or validated protocol to assess the swallowing function of adults with neurological diseases.

[Progress in evaluation of swallowing function after treatment of head and neck malignant tumors]

After treatment, patients with head and neckmalignant tumors may suffer from dysphagia, which may lead to aspiration pneumonia, cough and other complications, even threaten life, seriously affecting patients'quality of life. Through comprehensive evaluation of patients' swallowing function, clinicians can make corresponding rehabilitation plans to improve patients' quality of life.This paper summarizes a variety of subjective and objective evaluation methods for evaluating swallowing function of head and neck malignant tumors.

Utility of Pulse Oximetry to Detect Aspiration: An Evidence-Based Systematic Review

Pulse oximetry is a commonly used means to measure peripheral capillary oxyhemoglobin saturation (SpO₂). Potential use of pulse oximetry to detect aspiration is attractive to clinicians, as it is readily available, quick, and noninvasive. However, research regarding validity has been mixed. This systematic review examining evidence on the use of pulse oximetry to detect a decrease in SpO₂ indicating aspiration during swallowing is undertaken to further inform clinical practice in dysphagia assessment. A multi-engine electronic search was conducted on 8/25/16 and updated on 4/8/17 in accordance with standards published by the Preferred Reporting for Items for Systematic Reviews and Meta-Analysis Protocols (PRISMA). Inclusion criteria included use of pulse oximetry to detect aspiration with simultaneous confirmation of aspiration via a gold standard instrumental study. Keywords included dysphagia or aspiration AND pulse oximetry. Articles meeting criteria were reviewed by two blinded co-investigators. The search yielded 294 articles, from which 19 were judged pertinent and reviewed in full. Ten met the inclusion criteria and all were rated at Level III-2 on the Australian Diagnostic Levels of Evidence. Study findings were mixed with sensitivity ranging from 10 to 87%. Potentially confounding variables were observed in all studies reviewed, and commonly involved defining "desaturation" within a standard measurement error range (~ 2%), mixed populations, mixed viscosities/textures observed during swallowing, and lack of comparison group. The majority of studies failed to demonstrate an association between observed aspiration and oxygen desaturation. Current evidence does not support the use of pulse oximetry to detect aspiration.