Airways, ARDS & ventilatory strategies Nov 2013

Outline  Endotracheal tubes, tracheostomies and laryngectomies  ARDS  Evidence based ventilation  Proning, HFOV & ECMO

Airways  Oral vs nasal ETT  Does size matter?  Tracheostomy  Insertion  Care  When they “fall out”  TRACMAN, JAMA, 2013  Laryngectomy  ICU is the lair of the difficult airway

Acute Respiratory Distress Syndrome  “acute diffuse, inflammatory lung injury, leading to increased pulmonary vascular permeability, increased lung weight, and loss of aerated lung tissue…[with] hypoxemia and bilateral radiographic opacities, associated with increased venous admixture, increased physiological dead space, and decreased lung compliance.”  ARDSnet, NEJM, 2000.

Acute Respiratory Distress Syndrome  Within 7 days of a trigger  PaO2/FiO 2 <300 (40kPa)  Bilateral CXR changes  Not solely due to cardiac failure

Lung protective ventilation  6ml/kg IBW  RR up to 35 to achieve desired MV  Plateau pressure less than 30cmH 2 O  I:E ratio  Permissive hypercapnia  Paralysis  High PEEP?

Fixing the broken patient  Is there…  Patient-ventilator asynchrony?  Fixable contributory problems i.e. effusions, pneumothorax, bronchospasm?  Actually a problem?  Consider…  Recruitment  Paralysis  I:E ratio  PEEP  Fluid status  And then consider…

Proning  Improves  Distribution of ventilation and perfusion  Recruitment  Secretion clearance  Problems  Tube/line displacement  Pressure injury  Facial oedema  Early and for prolonged periods = improved mortality?  Guerin, NEJM, 2013

High Frequency Oscillatory Ventilation  RR bpm  TV < dead space  Convection, molecular diffusion, streaming, Pendelluft & cardiogenic mixing  Now predominantly discredited  OSCAR & OSCILLATE, NEJM, 2013

Extra Corporeal Membrane Oxygenation  Made famous by H1N1  Severe, reversible, respiratory failure where conventional methods are failing  Early rather than late  Venovenous vs venoarterial  Evidence in adults not (IMO!) conclusive  CESAR, Lancet, 2009

Summary  Types of airway & what to do if they fall out  ARDS  Ventilatory strategy  Proning, HFOV and ECMO