ECMO-/ECLS

Chapter 3

MECHANICAL VENTILATION

Martin Wakeham, MD

Marjorie Arca, MD

I. Indications
The indications for using mechanical ventilation can be divided into primary
respiratory, and non-respiratory (see below). The decision to place a patient on
mechanical ventilation is usually based on the combination of clinical judgment,
assessing the symptoms and signs of need for positive pressure ventilation and
laboratory test (e.g. blood gases, measurements of pulmonary mechanics, etc.)
The goal of placing someone on mechanical ventilation is to achieve
adequate/acceptable (not necessarily normal) gas exchange (oxygenation and/or
removal of CO2) while minimizing the chance of developing ventilator associated
lung injury (VALI).
Common indications for mechanical ventilation are:
Respiratory failure (hypoxemic and/or hypercarbic)
Pump dysfunction (CNS or neuromuscular dysfunction)
Primary lung disease (e.g. pneumonia, bronchiolitis, airway obstruction, etc.)Optimization of PaCO
Congestive heart failure (to decrease afterload, and work of breathing)^2 (as needed in traumatic brain injury)^
Protection of airways (coma, altered mental status)

(^) II. Ventilator Associated/Induced Lung Injury (VALI/VILI)
All forms of positive pressure ventilation (PPV) can cause ventilator
associated/induced lung injury. VALI/VILI is the result of a combination of the
following processes:
Inactivation of surfactant
Increase alveolar capillary permeability
Activation of inflammatory cells and release of cytokines