This statement is a common mantra amongst medical students, and something I was told by the ITU registrar (as well as “their saturations are fine”) at a peri-arrest in response to my suggestion of intubating a patient with critical airway obstruction. Whilst correct, this statement 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 (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, and clear warning of what was to come.
Reduction in oxygen saturations and the inability to speak are very late signs and therefore of little practical use. Should we wait for complete airway obstruction to occur before intubating?
If the clinical problem is a ventilatory one (consider neuro-muscular respiratory failure – another very poorly understood concept amongst medics), then saturation monitoring will be falsely re-assuring and will only provide “minutes” of warning before intervention is required.
This “PATIENT IS SPEAKING” mantra is worryingly widely used, and can lead to life-threatening delays in treatment. Where prompt diagnosis/intervention is required there is no substitute for a comprehensive clinical assessment.
Try not to get distracted by the ‘numbers’, or make your diagnosis based on one physical sign. Try to make the right (clinical) decision and make it fast.