Weaning Failure

Definitions Can’t get the tube out or Re-intubated within 48 hours 1/5 to 1/3 ventilated patients

Whenever you intubate a patient, your main goal is to extubate him/her.

Should we extubate..? Every patient should have a daily sedation hold AND ASSESMENT FOR EXTUBATION. Clinical feeling and various ‘tests’

Rapid Shallow Breathing Index Minimal resp support (5/5, CPAP, T-Piece) Freq / Tidal vol (L) <80 Should be OK >105 Prob will fail extubation ????????

What are the causes of weaning failure?

Airway & lung dysfunction Brain Cardiac Diaphragm & resp. muscles Endocrine

Airway Blocked tubes (sputum) Tracheomalacia (only apparent after removal positive pressure and/or ett. Granulation tissue from suctioning Bronchospasm

Lung Chest wall  Oedema (1L fluid = 1kg)  IAH  Pleural fluid Lung  Intrinsic PEEP  Alveolar fluid / collapse / consolidation  Interstitial disease

Brain Delirium increases risk 4x Anxiety Depression

Cardiac Largely due to intrathoracic pressure changes but also increased O2 demand from resp muscles. Weaning increases both left and right ventricular afterload, decreasing ejection fraction.

Diaphragm & Resp Muscles Respiratory drive is not the problem. CIPMN ‘Wasting’ – Ventilation prevents fatigue but promotes weakness!

Endocrine Adrenal insuffficiency Hypothyroidism Malnutrition Electrolytes – hypokalaemia, hypophosphataemia.

Weaning Protocols Increase success (speed) Reduce variability Avoid delays