Stroke: dysphagia increased the risk of chest infection.

Clinical bottom line (level 1b)

  1. A fifth of patients had a chest infection by 6 months.
  2. A half of patients had swallowing abnormalities, chest infection or aspiration at 6 months.
  3. Patients who had a first stroke were at increased risk of chest infection at 6 months if they had a delayed/absent swallowing reflex.
Mann et al: Stroke 1999; 30: 744-748
Expires November 2002

The study

Inception cohort study with objective outcomes, adjusted for confounding factors, not validated in an independent set of patients.

Setting: general hospital, Australia

117 patients (aged ?, 64% male) acute first stroke

Excluded if
  • >7 days after symptom onset
  • unconscious or medically unstable
  • had a history of previous swallowing impairment or a medical condition that could affect swallowing function




    • Cox proportional hazard multiple regression analysis was used to adjust for confounding factors.

    91% followed for 6 months
    Outcomes studied:
  • mortality
  • recurrent stroke
  • chest infection presence of 3 or more of: fever, productive cough with purulent sputum, abnormal respiratory examination, abnormal chest radiograph, arterial hypoxaemia and isolation of a relevant pathogen.
  • swallowing abnormality, chest infection or aspiration

    • Clinical assessment of swallowing function was conducted by two speech pathologists independent of each other and blinded to videofluoroscopic and CT brain scan findings.

    The evidence

    outcome time to outcome number of patients/total number %
    (95% CI)
    mortality 6 months 5/117 4.27%
    (0.61% to 7.94%)
    recurrent stroke 6 months 12/117 10.3%
    (4.76% to 15.8%)
    chest infection 6 months 26/117 22.2%
    (14.7% to 29.8%)
    swallowing abnormality, chest infection or aspiration 6 months 59/117 50.4%
    (41.4% to 59.5%)

    prognostic factor for
    chest infection     		time to outcome control rate (%) adjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    delayed/absent swallowing reflex 6 months 65/128
    (50.8%)     		11.8
    (3.30 to 49.6)     		2
    (2 to 4)

    prognostic factor for
    swallowing abnormality, chest infection or aspiration     		time to outcome control rate (%) adjusted OR
    (95% CI)    		 NNF+
    (95% CI)
    penetration 6 months 59/117
    (50.4%)     		14.0
    (4.00 to 51.0)     		2
    (2 to 3)
    delayed oral transit 6 months 59/117
    (50.4%)     		14.0
    (4.00 to 50.0)     		2
    (2 to 3)
    age >70 years 6 months 67/117
    (57.3%)     		5.00
    (1.40 to 21.0)     		3
    (3 to 13)
    male sex 6 months 46/117
    (39.3%)     		5.00
    (1.50 to 18.0)     		3
    (2 to 10)

    • Death of 4 of the 5 patients was due to chest infection.
    • The control rate for age over 70 years is an estimate.

    Citation

    1. Mann G, Hankey GJ, Cameron D: Swallowing function after stroke: Prognosis and prognostic factors at 6 months. Stroke 1999; 30: 744-748
    Contributor: Clare Wotton and Musab Hayatli, November 1999
    Reviewer:

    Clinical Question.
    Patient first stroke
    Intervention or Exposure dysphagia
    Comparison no dysphagia
    Outcome mortality and recurrent stroke