Dysphagia Screening: a Hard Act to Swallow

Hospital-acquired aspiration pneumonia (HAP) is a serious morbidity tied to stroke-related dysphagia. HAP requiring antibiotics occurs in 5.8% of hospitalized stroke patients, or 1 of 17 patients.  Patients developing HAP are at 5-fold increase in in-hospital mortality (12.4% versus 2.3%).1 Clearly, interventions that reduce this adverse outcome are needed.  That dysphagia screening should improve health outcome in stroke patients seems intuitively obvious since pneumonia risk is greatest in those patients who have aspiration.2

The symposium panel begins by clarifying the differences between a dysphagia “screen,” which is an initial pass or fail evaluation to determine the immediate safety risk of a newly admitted stroke patient to take fluid or food by mouth.  It must be differentiated from the “clinical dysphagia assessment,” generally done by speech therapists, and consisting of a clinical/bedside evaluation and possibly supplemented with an “instrumented dysphagia assessment,” which incorporates data from either a videofluoroscopic swallowing assessment or a fiberoptic endoscopic evaluation of swallowing (FEES).  Failure on a dysphagia screen prohibits immediate p.o. intake and generally triggers a subsequent clinical dysphagia assessment.  Passing a dysphagia screen likely leads to no further formal swallowing evaluation. Practical concerns make requiring a comprehensive assessment in all patients not feasible on a national level, because of limitations in skilled personnel (primarily speech and language pathologists), and attendant lack of 24/7 availability.

Historically, awareness of dysphagia in stroke and its attendant risks of aspiration and pneumonia has gradually increased over the past 30 years.  In the 1980s through the mid 1990s the decision to allow food and fluids by mouth was generally done at the bedside, if done at all, by either the nurses or physicians who might consider the patient’s gag reflex, or level of consciousness, and would occasionally give a test glass of water.  At that time G-tube placement was an open surgical procedure, and not commonly used.  With the advent of percutaneous gastrostomy placement, decisions regarding the need to delay p. o. feeding became a more viable choice.  By the late 1990s and early 2000s, as noted in the conference proceedings, research on screening tools and improved diagnostic evaluation of swallowing indicated a need for valid, reliable dysphagia screens that could be administered by a range of professionals. In 2007 the AHA/ASA guidelines on acute ischemic stroke introduced a new recommendation for assessment of swallowing before starting eating or drinking (Class I, Level of Evidence B), and this recommendation has been continued in the current acute ischemic stroke guidelines published this year.3,4 Dysphagia screening was also endorsed by the 2010 VA/DOD guideline on the management of stroke.5

A recent analysis of data from the Paul Coverdell National Acute Stroke Registry database strongly suggested that failing or not receiving a dysphagia screening was associated with pneumonia.  Of 18,017 patients discharged from 222 hospitals in 6 states in 2009, the incidence of pneumonia was higher in patients who did not receive dysphagia screening compared to patients who successfully passed dysphagia screening before oral intake. The highest rates of pneumonia were in the patients who failed the dysphagia screening.6

But recent work has called into question a clear causal connection between the process of dysphagia screening and improved health outcomes. 

In a study of stroke patients admitted to the ICU, it was found that pneumonia was associated with a higher NIHSS score, more advanced age, and nasogastric tube or endotracheal tube placement. After adjusting for these variables, passing the dysphagia screen in the ICU showed a borderline trend toward reducing pneumonia, but passing the dysphagia screen was not associated with a reduction in in-hospital deaths.7  More importantly, a recent extensive review of 314,007 patients with ischemic stroke treated in 1,244 GWTG-S hospitals over a 7-year period raised questions about the value of dysphagia screening.1 This analysis found that those with hospital-associated pneumonia had higher NIHSS scores (median 10 vs. 4), were older, and had an increased length of stay and in-hospital mortality.  A bedside swallow screening prior to oral intake was associated with a higher odds ratio for HAP, but this odds ratio was markedly reduced when controlling for stroke severity as measured by the NIHSS.  Thus, dysphagia screening is confounded by the severity of the stroke, and the authors suggest that additional controlled trials to determine dysphagia screening effectiveness are needed.

So the evidence-based value of dysphagia screening is currently in flux.  A heightened awareness of this current controversy regarding dysphagia screening was brought into sharp focus by the National Quality Forum’s failure to endorse dysphagia screening as a performance standard, and by the Joint Commission’s retirement of dysphagia screening as a performance standard for acute stroke in 2010. 

In response to the uncertainty and current controversy, this symposium has consolidated and enumerated the characteristics of valid and reliable dysphagia screening tools with adequate sensitivity and specificity and predictive strength to accurately detect aspiration, and thus have solidified the state of science base to the discussion. 

The big question is not only what dysphagia screening procedure is valid and reliable, and does that dysphagia screening procedure not only predict morbidity from dysphagia, but does the process of screening lead to improved health outcomes.

1. Masrur S, Smith EE, et al. Dysphagia Screening and Hospital-acquired Pneumonia in Patients with Acute Ischemic Stroke: Findings from Get with the Guidelines-Stroke. J Stroke Cerebrovasc Dis 2013.
2. Martino R, Foley N, et al. Dysphagia After Stroke: Incidence, Diagnosis, and Pulmonary Complications. Stroke 2005;36(12):2756-2763.
3. Adams HP Jr, del Zoppo G, et al. Guidelines for the early management of adults with ischemic stroke: a guideline from the American Heart Association/ American Stroke Association Stroke Council, Clinical Cardiology Council, Cardiovascular Radiology and Intervention Council, and the Atherosclerotic Peripheral Vascular Disease and Quality of Care Outcomes in Research Interdisciplinary Working Groups: The American Academy of Neurology affirms the value of this guideline as an educational tool for neurologists. Circulation 2007;115(20):e478-534.
4. Jauch EC, Saver JL, Adams HP Jr, Bruno A, Connors JJ, Demaerschalk BM, Khatri P, McMullan PW Jr, Qureshi AI, Rosenfield K, Scott PA, Summers DR, Wang DZ, Wintermark M, Yonas H; on behalf of the American Heart Association Stroke Council, Council on Cardiovascular Nursing, Council on Peripheral Vascular Disease Council, and Council on Clinical Cardiology. Guidelines for the early management of patients with acute ischemic stroke: a guideline for healthcare professionals from the American Heart Association/ American Stroke Association. Stroke. 2013: published online before print January 31, 2013, 10.1161/STR.0b013e318284056a.
5. Veteranʼs Administration/Department of Defense Clinical Practice Guideline Management of Stroke Rehabilitation, published October 2010.
6. Lakshminarayan K, Tsai AW, et al. Utility of dysphagia screening results in predicting poststroke pneumonia. Stroke 2010;41(12):2849-2854.
7. Yeh SJ, Huang KY, et al. Dysphagia screening decreases pneumonia in acute stroke patients admitted to the stroke intensive care unit. J Neurol Sci 2011;306(1-2):38-41.