Current Pragmatic Experience
With this controversy in mind, the philosophic position adopted since 1974 by the Critical Care Service at Mayo in conjunction with our medical and surgical colleagues has been that tracheostomy should be considered at day 10 of intubation and performed then unless extubation or de^th was imminent. To examine this in practice, we reviewed the Mayo experience with prolonged mechanical ventilation since 1970 and reexamined a patient series collected in 1982-83 and published in 1986. In Table 2 tne number of patients who required mechanical ventilatory support in ICUs in two Mayo-affiliated hospitals is shown for selected years from 1970 to 1984. Pulmonary artery catheter use in patients in general medical and surgical units (not cardiac surgical, not coronary care) is also shown. Fairly stable mortality rates were noted and these were comparable to data from other centers.
A cohort of 323 consecutive patients was chosen from 1 of these two hospitals in 1982 to 1983, such that all patients admitted to the general medical/general surgical ICUs were screened and selected for follow-up if they required mechanical ventilation for more than 24 h (326 episodes). Patients were placed in 1 of 6 groups, depending on the cause and characteristics of the respiratory failure (Table 3). Sixty-three (20%) of these 323 patients were subjected to tracheostomy and were further analyzed (Table 4). The average number of days of mechanical ventilation prior to tracheostomy, where these data were available (55 of 63), was 13.6 ±6.3 (n = 55, mean ± SD), with a range of 1-28 days. The overall mortality for patients with tracheostomy (32%, n = 63) was not different from that for all patients (34%, n = 323), but the time for mechanical ventilation was significantly prolonged (Table 4).
Sixty-one of these 323 patients (19%) were subjected to mechanical ventilation prolonged beyond 20 days (mean + 1SD of usual time before tracheostomy). Nine of these 61 patients did not receive tracheostomy at any time. Five of these 9 died; of the 4 who survived, only 1 required mechanical ventilation beyond 25 days. This patient was managed for 58 days with an endolaryngeal tube. No sequelae beyond mild hoarseness were noted in this individual case.
Table 2—Acute Respiratory Failure: Mortality Rates Associated with Mechanical Ventilation* (Mayo Clinic, 1970-84)
|Duration of Mechanical Ventilation||PulmonaryArteryCathetersf|
|>24 h||<24 h|
|n||Mortality, %||n||Mortality, %|
Table 3— Mortality of Batients in Acute Respiratory Failure Requiring Prolonged (>24 h) Mechanical Ventilation* (Mayo Clinic 1982-83)
|Acute lung injury (uncomplicated)||21||43|
|Multiple system failure||60||82|
|Chronic lung disease||52||27|
Table 4—Average Days of Mechanical Ventilation with and without Tracheostomy by Subgroup (Mean ± SD)
|Subgroup||Days before Tracheostomy/Patients, No.||Total days of mechanical ventilation/Fatients, No.|
|Acute lung injury||20.5||2||30.5||2||13.1 ±3.0||21|
|Multiple system failure||16.4 ±5.5||16||37.7±3.0||17||18.5 ±2.3||60|
|Chronic lung disease||14.0±6.1||17||50.8 ±4.1||19||22.9 ±5.0||52|
|Medical-neurologic||9.1±5.0||9t||27.6 ±3.8||11||9.3 ±2.2||52|
|Surgical||10.7 ±2.8||6t||17.1 ±1.9||10||3.8 ±0.5||113|