A 65-year-old man had an out of hospital cardiac arrest secondary to a large anterior ST elevation myocardial infarction. His ICU stay has been complicated by aspiration pneumonia. He is now day 14 from admission, with a tracheostomy in situ, and has started weaning from ventilation.
You have been asked to review him as he is communicating that he ‘can’t get enough air’ despite ongoing mechanical ventilatory support.
How would you manage this patient who reports being breathless on a ventilator?
Urgent attention to A, B, C – Give 100% oxygen and exclude/treat immediate threats to life
Focused history and examination considering differential diagnoses:
Patient factors
Airway / trache – blocked, displaced or too small diameter
Respiratory eg pneumonia, PE, PTX
Cardiac – ongoing ischaemia, cardiac failure, fluid overload
Neuromuscular – weakness, fatigue
Sepsis
Metabolic
Central – increased respiratory drive, pain, agitation
Ventilator factors
Unsuitable mode
Triggering threshold too high
Inadequate flow
Prolonged inspiratory time
Inappropriate cycling
Inadequate pressure support
Ventilator malfunction
Treatment:
100% O2, suction trachy, exclude obstruction/malposition, end tidal CO2 etc
Assess ventilation
Mode, respiratory rate and pattern
Spontaneous and delivered TV / MV / airway pressures
Expiratory flow-time curve, PEEPi (if possible)
Titrated pain relief
May need to carefully sedate to gain control of the situation if he is very distressed and agitated. Rarely need to paralyse after sedation
Investigations
Basic Investigations – eg ABG, ECG, CXR, cultures
Further investigations as indicated – eg Echo, CTPA, BNP, Troponin etc
This question lends itself well to a systematic approach.