This statement is a common mantra amongst medical students, and something another registrar said (“the patient is speaking and their saturations are fine”) at a peri-arrest in response to my question as to whether the patient had critical airway obstruction.
Whilst strictly correct, the statement “the patient is speaking, therefore their airway is patent” I feel is simplistic and misleading.
A patient can speak whether their airway calibre is the usual 25mm (standard tracheal calibre) or 15mm, or even 5mm. Note that ‘obstruction’ means limitation of flow, and this can be partial or complete. There are much more sensitive and early signs of airway obstruction that occur prior to the patient stopping speaking. Such as: recruitment of accessory muscles (denoting increased work of breathing – this can occur for a variety of reasons including but not limited to airflow obstruction), stridor (a monophonic inspiratory wheeze denoting turbulent flow across a partially obstructed passage), intercostal/subcostal recession and “see-saw-ing” (denoting the greater trans-thoracic pressure gradient required to generate flow across a partially obstructed passage) are a few examples. These are all clinical signs that this patient was displaying, of course meaning they had airway obstruction (later confirmed by CT which revealed multiple cervical and mediastinal nodes compressing the trachea) – it may not have been total airway obstruction (the patient could talk) but is that a useful syndrome for us to clinically recognise? The inability of the patient to speak is a very late sign and therefore of little practical use. Oxygen saturations similarly provide very little warning, and in the case of ventilatory compromise (i.e. neuro-muscular/chest wall related respiratory failure) oxygen saturation monitoring will be falsely re-assuring until that critical moment when total lung capacity encroaches upon tidal volume. It will therefore only provide “minutes” of warning before intervention is required.
This “PATIENT IS SPEAKING” mantra is not uncommonly heard, and I feel can lead to life-threatening delays in treatment. Where prompt diagnosis/intervention is required there is no substitute for a comprehensive clinical assessment – not a casual glance at the observations chart. Observations do not constitute a clinical assessment. Observations are a very blunt screening tool used to highlight patients whom are in need of a clinical assessment.
Try not to get distracted by the ‘numbers’, or make your diagnosis based on one physical sign. The correct clinical decision requires a comprehensive clinical assessment.