Key messages

• Inspiratory time governs the inspiratory-to-expiratory (I:E) ratio and inspiratory flow rate. In mechanically ventilated patients, a 'standard' inspiratory time of 0.8 to 1.5 s should be adjusted according to the following.

Oxygenation: improvement in oxygenation may follow lengthening of the inspiratory time to increase mean airway pressure. Risk of ventilator-induced lung injury: shortening the expiratory time increases the possibility that auto-PEEP will develop. Cardiovascular stability: prolonged inspiration can cause hemodynamic instability by impeding venous return.

Level of spontaneous respiration and mode of ventilation: lengthened inspiratory time is usually poorly tolerated by patients who are breathing spontaneously or lightly sedated.

• Inspiratory waveform can only be adjusted in volume-targeted ventilation. The choice depends upon the following.

Patient comfort: square or sinusoidal waveforms are often well tolerated. Oxygenation: a descending waveform may improve Pao2.

Sleep Apnea

Sleep Apnea

Have You Been Told Over And Over Again That You Snore A Lot, But You Choose To Ignore It? Have you been experiencing lack of sleep at night and find yourself waking up in the wee hours of the morning to find yourself gasping for air?

Get My Free Ebook


Post a comment