Exam

Single Breath Counting

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Single Breath Counting

  • Indications
  1. Myasthenia Gravis
    1. Evaluate for Respiratory Failure (Bellows Failure) in myasthenia crisis
    2. Used in combination with Forced Vital Capacity (FVC) and negative Inspiratory Force (NIF)
  2. Respiratory Assessment in other acute respiratory illness
    1. Has been used as a triage tool in Telemedicine (e.g. Covid19)
  • Technique
  1. Patient count out loud as high as they can after a single inhalation
  • Interpretation
  1. Normal: 40 to 50
  2. Risk for Respiratory Failure (need for Ventilatory support): 15 to 20
  • References
  1. Bartfield (1994) Ann Emerg Med 24(2):256-9 +PMID: 8037392 [PubMed]