New Swallowing Test Reduces Pneumonia in Stroke Patients

Daniel M. Keller, PhD

May 30, 2012

May 30, 2012 (Lisbon, Portugal) — A test to detect swallowing difficulties in patients with stroke is an easy, sensitive, and highly predictive screening tool, a new study shows. Use of the test was associated with a dramatic drop in the incidence of pneumonia among stroke patients, researchers report.

The Modified Mann Assessment of Swallowing Ability (MMASA) can be performed at the bedside in about 5 minutes, making it unnecessary to wait for a speech and language therapist to conduct the more involved Mann Assessment of Swallowing Ability (MASA) before letting patients eat, said Neil Baldwin, BM, BS, consultant stroke physician and leader of the Specialist Stroke Team at Frenchay Hospital of the North Bristol NHS Trust, Bristol, United Kingdom.

The MASA is a detailed assessment of dysphagia that takes about an hour of a speech and language therapist's time, Dr. Baldwin told Medscape Medical News. The MMASA, on the other hand, "is a simple 5-minute screening test which can be implemented into part of the routine clinical examination of a stroke neurologist," he said.

"It means that patients can start eating straight away," he said. "And it means that we can be more confident that they're going to be eating safely."

Their findings were reported here at the XXI European Stroke Conference.

75% Drop in Pneumonia

The MMASA had previously been validated by 2 neurologists on 150 stroke patients. In the present study, stroke physicians and speech and language therapists administered the MMASA, and results compared favorably with those from the full specialist swallowing assessment using the MASA (r = 0.77; P < .001).

The test evaluates 10 domains important to swallowing ability, and each domain has a maximum score of 10; thus, a perfect score is 100. Analysis of receiving-operating characteristic curves indicated that the optimal cut-off point for the data was an MMASA score of 97, which gave a sensitivity of 72.3%, a specificity of 79.2%, a positive predictive value of 75.6%, and a negative predictive value of 81.8%.

All stroke patients admitted to Frenchay Hospital between November 2009 and January 2011 received an MMASA screening. Randomly selected patients had a full specialist swallowing assessment using the MASA within 2 hours of the MMASA. MASA has been validated against videofluoroscopy, the gold standard for swallowing assessment.

The study included 50 male and 50 female patients with acute stroke (average age, 78.3 years). The swallow screen was done an average of 55 hours after stroke and 38 hours after hospital presentation.

Using the MMASA, the investigators found that 47% (95% confidence interval, 37% - 57.2%) of the patients had swallowing impairment. Implementing the test reduce the incidence of pneumonia at Frenchay Hospital by 75%.

"In terms of pneumonia, prior to introduction of this screening test, we had rates of 12% per annum in our stroke service, which is very comparable to the 16% across United Kingdom hospitals," Dr. Baldwin said. "Following the introduction of the screening test we reduced the incidence to 3%, whereas...national figures were still 13% — so, much better incidence of pneumonia, which obviously improves the quality of care, shortens length of stay, and improves outcome."

The year 2008 pre-MMASA figures are based on more than 600 stroke cases at the hospital, and the 2010 post-MMASA figures come from just over 900 cases.

It's estimated that 40% to 65% of all patients with acute stroke have swallowing difficulties. The approximately 1-hour MASA test is done at some point during the hospitalization to determine the extent of swallowing disability and plan for rehabilitation but may be delayed by as long as 2 days depending on staff availability. However, United Kingdom guidelines recommend screening patients for dysphagia within 4 hours of presentation to the hospital.

Development of MMASA

Dr. Baldwin and colleagues began development of the MMASA in 2008 and implemented it at their hospital in 2010. It now consists of 10 unweighted domains.

"It's actually a very straightforward 10 domains, but we know that some of the domains contribute much more to the outcome of the test than others, and we're hoping to simplify it and then train both nursing and junior medical staff to do the test, as well," Dr. Baldwin noted.

It is now part of the hospital's standard neurologic assessment of stroke patients, "and it could easily be done by most stroke units because the test doesn't require any specific specialized training, which some of the other screening tests do require."

Compared with the MMASA, other tests have higher sensitivity but poorer specificity or require specially trained nurses to administer them.

Impressive Results

Idris Ibrahim, MB,BS, DTM&H, a stroke physician at the Great Western Hospital in Swindon, United Kingdom, who was not involved in the study, said he intends to visit Frenchay Hospital to learn to do the MMASA.

"Within a space of 2 years of using this scale, they were able to reduce the incidence of pneumonia from 12% to 3%, which is very, very good," he commented to Medscape Medical News. "In fact, compared to other hospitals in the UK... it's very impressive. I'm really, really impressed by this study."

Although Dr. Ibrahim thinks the MMASA still requires further validation, he liked the fact that it does not require any technology and that it is simple to do with very little additional training. "I think it's something that will generate a lot interest in the future," he predicted. "It helps patients' care, and it doesn't cost anything."

He also believes the MMASA has the potential to reduce hospital costs for stroke treatment. "If you can prevent 1 pneumonia in hospital, now you've saved the hospital bed time, you've saved a lot of medication cost, a lot of staff involvement and care and time — that's a lot of money saved," he said. "And now with the advent of resistant bugs...if we can reduce the rate and incidence of pneumonia in stroke patients, I think we're doing a good job."

There was no commercial funding for the study. Dr. Baldwin and Dr. Ibrahim have disclosed no relevant financial relationships.

XXI European Stroke Conference. Abstract #24. Presented May 22, 2012.

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