Key Point

In mechanically ventilated patients, waiting more than 21 days to perform a tracheostomy may decrease the success of weaning attempts and increase the incidence of adverse outcomes.

TAIPEI, TAIWAN—Tracheostomy is a common procedure, performed in about 25% of ICU patients. Although it has several advantages over standard intubation, having a tracheostomy is also associated with the risk of serious complications.

The medical community has yet to arrive at a consensus regarding the timing of tracheostomy. In fact, the 1989 American College of Chest Physicians (ACCP) Consensus Conference on Artificial Airways in Patients Receiving Mechanical Ventilation concluded that the appropriate duration of translaryngeal intubation could not be defined. More recently, the 2001 ACCP guidelines for discontinuing ventilatory support recommended tracheostomy for patients requiring long-term mechanical ventilation.

In an attempt to determine the optimal timing for tracheostomy and its impact on successful ventilator weaning, researchers at the National Taiwan University Hospital in Taipei conducted a retrospective record review of 163 patients who were intubated in the hospital’s ICU. The study results favored early tracheostomy, with the researchers finding that a tracheostomy performed after 21 days of intubation was associated with a higher incidence of failure to wean. However, the timing of a tracheostomy did not affect hospital mortality.¹

Patients’ medical records were analyzed for underlying disease, age, sex, reason for intubation, APACHE II score, duration of mechanical ventilation, complications of tracheostomy, pneumonia after tracheostomy, length of ICU stay, and ICU or hospital mortality. Clinical data recorded within 72 hours before tracheostomy were also analyzed.

In all cases, the timing of tracheostomy was left up to the attending physician. When patients had stable hemodynamic status, improved oxygenation, and controlled infection, weaning from mechanical ventilation was attempted. Complications that occurred within seven days after tracheostomy were considered early complications and those occurring after seven days were considered late.

LATE TRACHEOSTOMY, MORE PROBLEMS

The most common early complications from tracheostomy were bleeding and subcutaneous emphysema. The most common late complication was bleeding, followed by air leakage and tracheal stenosis. In all, 78 patients were successfully weaned from the ventilator and 85 had failure to wean. The one difference in clinical characteristics between those who were successfully weaned and those who were not was that more of the successfully weaned patients had neurological disease. In addition, the failure-to-wean group had higher white blood cell counts, lower platelet counts, and poor Pao₂/FIo₂ ratios.

Higher rates of posttracheostomy pneumonia occurred in the failure-to-wean group. These patients also had longer posttracheostomy mechanical ventilation periods. Weaning was successful in 56.4% of patients with an intubation period within 21 days versus 30.2% in those who were intubated for more than 21 days. Prolonged intubation was also associated with increased ICU mortality compared to shorter intubation periods (28.3% vs 14.5%, respectively). The investigators found an association between duration of intubation before tracheostomy and longer ICU stay—even in patients who were successfully weaned.

“There are no definitive guidelines and there is a paucity of studies about the timing of tracheostomy,” said Kuan-Yu Chen, MD, Attending Physician in the Division of Pulmonary and Critical Care Medicine at National Taiwan University Hospital. “Timing of tracheostomy might be influenced by the family’s attitudes and by the judgment of the attending physician.” Dr. Chen noted that extremely ill patients could suffer serious complications from early tracheostomy. Conversely, patients who have a greater probability of successful extubation should also probably not have an early tracheostomy, because they do not need it. “It is difficult to define how long we should wait for a patient’s condition to stabilize, or for successful weaning and extubation,” explained Dr. Chen.

Despite the differences in weaning success and ICU mortality, overall hospital mortality was not affected. The investigators pointed out that prolonged intubation may increase the risk of infection by breaking down the local barrier and bronchial hygiene. It can also result in higher rates of posttracheostomy pneumonia, which in turn is associated with failure to wean. “If one waits longer than 21 days,” they concluded, “then it may be better to forego tracheostomy altogether.”

—Gale Jurasek

Reference
1. Hsu CL, Chen KY, Chang CH, et al. Timing of tracheostomy as a determinant of weaning success in critically ill patients: a retrospective study. Crit Care. 2005. Epub ahead of print.

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