The Science Journal of the American Association for Respiratory Care

1996 OPEN FORUM Abstracts

Getting Rid of the Endotracheal Tube

Charles G. Durbin, Jr., MD Monday, November 4, 1996

The final step in weaning a patient from mechanical ventilation is removing the endotracheal tube. If an artifical airway is not needed it should be removed at the earliest possible time. Translaryngeal intubation results in vocal cord damage within several days. Cord edema is followed by ulceration. This may progress to synechia of the cords and permanent disability. Tube tip complications may be increased by movement of the endotracheal tube. These include ulceration, hemorrhage, tracheal necrosis, and perforation. Following extubation these may heal with scaring and development of tracheal stenosis. Similar injuries may occur at the cuff site, here the injury is likely to be circumferential and lead to tracheomalacia or tracheal stenosis. The duration of intubation that can be tolerated without these complications is not known and depends on the clinical status of the patient. The sickest patients probably are at the greatest risk. The risk of too early extubation must be weighed also.

It is not clear how long to delay tracheostomy, but usually 2-3 weeks of translaryngeal intubation precedes tracheostomy. If a patient is likely to need an artificial airway for a prolonged period of time, tracheostomy may be performed earlier. We examined data from all patients receiving temporary tracheostomy during a one-year period at a university hospital. 127 temporary tracheostomies were performed during the study period. The average time of intubation before tracheostomy was 20 days in medical and 13 days in surgical patients. Eight of the 11 patients receiving tracheostomy on the first day were trauma patients sustaining acute head, face, chest, cervical spine or a combination of these injuries. The remaining patients with neurologic injuries received tracheostomies an average of 10 days after intubation, when the need for prolonged airway protection could be predicted.

If a patient has been successfully weaning from mechanical ventilation and excessive oxygenation support, several other concerns should be addressed prior to removal of the endotracheal tube. These aspects are listed below:

Factor Possible Measurements

Oxygenation PaO_{2} >55 on 60% O_{2}

PEEP < 5, Spontaneous Ventilation

Ventilation PaCO_{2} < 60 and pH>7.25

Spontaneous Ventilation, ?PSV < 10

Acceptable Mechanics Vital Capacity>10 cc/kg

Necessary Minute Ventilation < 12 l/min

Spontaneous Rate < 30

Rapid Shallow Breathing Index < 105

Work of Breathing < 15% of Total Energy

Strength Max Negative Inspiratory Pressure < -35

Acceptable Deadspace Vd/Vt < .6

Mental Status Awake*

Airway Protective Reflexes Strong Cough, Adequate Gas Reflex*

Other System Stability ?Off Vasopressors, IAPB, LVAD, etc.

Pending Need for Airway Planned Surgery

Reintubation Concerns Difficult Airway Issues

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