Mechanical Ventilation Complications

-Circulation:

-Thorax

-Abdomen

-Periphery

-Mechanical ventilation results with changes in lung pressure and volume which might result with:

-Atrial filling (preload) reduction

-Resistance to ventricular emptying (afterload)

-Right atrial pressure increases during mechanical ventilation which can lead to decreases in RV preload and a fall in cardiac output

-Pneumothorax

-Oxygen toxicity

-Ventilator associated pneumonia

-Neuromuscular and muscular weakness

-Sedation and delirium

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Mechanical Ventilation and ARDS

-Ventilator-induced lung injury (VILI):

-Lung stress (pressure)

-Lung strain (volume)

-Plateau pressure?

-Benefit of using lung protection ventilation:

-Minimize overdistension

-Minimize hemodynamic compromise

• ARMA by ARDS Network:
  • Lower tidal volumes starting at 6 ml/kg, reduced by 1 ml/kg to maintain plateau pressure ≤30 cmH2O
  • Traditional tidal volumes starting at 12 ml/kg, reduced by 1 ml/kg PBW to maintain plateau pressure ≤50 cmH2O
  • Volume assist-control for both
  • Low tidal volume ventilation resulted with lower mortality and more ventilator-free days

-Where to start from:

-Tidal volume = 6 mL/kg

-High respiratory rate of 25-30 breaths/ min

-Partial pressure of carbon dioxide (PaCO2) <50 mmHg

-Plateau pressure <30 cm H2O

-PEEP of >5 cm H2O in all ARDS patients

-High PEEP reserved for moderate to severe ARDS to increase oxygenation without decrease respiratory compliance or hemodynamic status

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Sedation

-Respiratory center inhibition

-Reduction of lung injury

-Improve patient-ventilator synchrony

-Reduction of oxygen consumption

-Agents:

-Opioids

-Propofol

-Benzodiazepines

-Over sedation:

-Prolonged mechanical ventilation

-Increase length of stay

-Increased risk of complications

-Increased diagnostic testing = $$$

-Delirium