0521779407-22 CUNY1086/Karliner 0 521 77940 7 June 4, 2007 21:23
Ventilator Management in the ICU 1523➣Patient-ventilator dyssynchrony – “bucking” the ventilator;
adjust tidal volume, respiratory rate, inspiratory flow rate, venti-
lator mode, or increase sedation
➣Hypoventilation – when minute ventilation is inadequate; from
mucous plugging or atelectasis
➣Hyperventilation – more common with AC; occurs with anxiety,
dyspnea, fever, central causes; can result in respiratory alkalo-
sis
➣Oxygen toxicity – safe level not clearly established in humans;
FIO2 <0.40 probably safe, FIO 2 > 0.8 may be dangerous over pro-
longed period
➣Ventilator-associated pneumonia – risk factors are prolonged
mechanical ventilation, H 2 -antagonists
■Endotracheal intubation
➣vocal cord trauma, tracheal stenosis
■Nasotracheal intubation
➣sinusitis
■Contraindications to treatment: relative
➣AC in patients with asthma or COPD exacerbation
➣SIMV in Acute Lung Injury or ARDS (AC with low tidal volume
reduces mortality)
➣PCV in patients who have changing lung compliance or airway
resistancefollow-up
■Key issue is when patient can be liberated from mechanical ventila-
tion (“weaning”):
➣Respiratory failure and/or underlying medical condition must
be improving
➣Reduce sedation and analgesia
➣Assess ability to protect airway (underlying medical and neuro-
logic status, level of consciousness, gag reflex)
■Daily trial of spontaneous ventilation for 30 minutes to 2 hours –
either CPAP with pressure support≤5 cm water OR T-piece; termi-
nate trial for overt distress, tachycardia, hemodynamic instability,
respiratory rate > 30
■Rapid shallow breathing index=respiratory rate (breaths/minute) /
tidal volume (liters)
➣index less than 105 associated with successful weaning from ven-
tilator