To further examine the major determinants for tracheostomy in each of these 6 diagnostic subgroups, we looked at the relationships between the underlying diagnosis, the use of invasive monitoring, and the time during which mechanical ventilation was required (Table 5, Fig 1). In addition, we noted whether tracheostomy was discontinued at hospital dismissal or continued. Our bias led us to believe that the major positive determinants would be (1) time of needed intubation (>7-10 days) and (2) anticipation of future need for tracheostomy, whereas the major negative determinants would be (3) anticipation of imminent death (not wishing to add unnecessary charges to the patient bill), or (4) anticipa tion of imminent recovery and easy extubation. This is borne out by our findings.
There is a direct relationship between the percentage of each patient subgroup that received tracheostomy and the average total days of mechanical ventilation for that subgroup (Fig 1). Of 36 survivors, 21 (58%) from the 55 patients who received tracheostomy (complete data) were dismissed with the tracheostomy in place, and 11 of these 21 were still requiring mechanical ventilatory support for all or part of each day. The 3 subgroups with relatively short times to tracheostomy contained a significant number (10) of patients with neurologic diseases (Table 4). These 10 patients had an average time to tracheostomy that was 62% of the norm (8.4 vs 13.6 days). At the other extreme were patients with either acute lung injury alone (2 survivors >20 days without tracheostomy) or multiple organ system failure (5 deaths >20 days without tracheostomy), in which the average time to tracheostomy was beyond the norm.
After review of both the theoretic comparative advantages and disadvantages of prolonged endolaryngeal intubation and of tracheostomy and the current pragmatic experience in a busy rural referral center, is there an absolute time limit to use of endolaryngeal intubation in adults? We believe this question remains open, and that the different rates of occurrence of laryngeal and tracheal damage in a given center may be major factors which will determine that centers practice. A multicenter trial needs consideration, and the diabetic female needs particular attention.
The current mode of practice at Mayo is to perform tracheostomy for patients in acute respiratory failure after 14-20 days of prolonged airway management. The factors arguing against increasing use of tracheostomy at Mayo are that severe complications are possible with tracheostomy, and the procedure adds $2-$3,000 to costs.
The approximate charge for endotracheal intubation (tube placement) is $90; for tracheostomy (operation, anesthesia, and operating room) is $2,200 and (change of tube) $100; and the daily maintenance for either is $20. These disincentives will not be offset in our practice by increased Medicare reimbursement for prolonged mechanical ventilation inherent in DRGs 474 and 475. Early tracheostomy may, however, be indicated by neurologic diagnosis or a high ISS (>30), factors that may indicate a prolonged need for airway management. On the other hand, prolonged intubation may be quite safely conducted without airway sequelae in certain individuals.
Table 5—Use of Pulmonary Artery Catheters and Tracheostomy in Rttients in Acute Respiratory Failure
|N||Pulmonary Artery Catheter||TVacheostomy||1-yr Mortality, %%|
|Mortality % of Group||No.|
|% of group||No.|
|Acute lung injury||21||81||17||10||2||48|
|Multiple system failure||60||73||44||28||17||88|
|Chronic lung disease||52||42||22||37||19||46|