Abstract & Commentary
Early or Late Tracheostomy Placement: Optimal Timing Remains Unclear
By Linda L. Chlan, RN, PhD, School of Nursing, University of Minnesotae, is Associate Editor for Critical Care Alert.
Dr. Chlan reports that she receives grant/research support from the National Institutes of Health.
SYNOPSIS: Based on the findings of this meta-analysis of seven randomized controlled trials, early (7 days after intubation) or late (any time after 7 days) tracheostomy placement did not alter clinical outcomes in study patients, including no differences in mortality, incidence of ventilator-associated pneumonia, duration of mechanical ventilation, ICU stay, hospital stay, or sedation.
SOURCE: Wang F, et al. The timing of tracheotomy in critically ill patients undergoing mechanical ventilation: A systematic review and meta-analysis of randomized controlled trials. Chest 2011;Sep 22. [Epub ahead of print]
This paper presents the findings from a systematic review and meta-analysis of available randomized, controlled trials (RCTs) published through July 2011 and retrieved from a variety of electronic search databases worldwide. The authors followed the reporting guidelines of Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA). The quality of the reviewed RCTs followed the methods recommended by the Cochrane Collaboration. The primary outcomes examined included short-term mortality (hospital mortality or mortality within 90 days follow-up) and incidence of ventilator-associated pneumonia (VAP). Secondary outcomes were long-term mortality (mortality between hospital discharge and at least 1-year follow-up), duration of mechanical ventilation, duration of sedation, length of ICU stay, length of hospital stay, and complications such as events that were life-threatening and required intervention or resulted in prolonged hospitalization.
The authors included seven RCTs that met their pre-established criteria; a total of 1044 patients were included in these studies. The RCTs were conducted in North America (3), Europe (3), and North Africa (1), with no representation of Latin American or Asian countries or Pacific nations such as Australia. Tracheostomy procedures included those performed at the bedside and those placed in the operating room. Three of the seven RTCs were multicenter trials. Six of the seven trials reported their specific weaning protocols. Age of patients included in the trials ranged from 40-66 years. The seven trials examined a heterogeneous population including medical, medical-surgical, trauma, head injury, burns, and post-cardiac surgery patients. Two trials were judged to be biased due to one being stopped early after an interim analysis, and the other due to imbalance after randomization. There was no evidence among the trials of publication bias.
The findings from the meta-analysis on the pre-determined primary outcomes concluded that early tracheostomy placement did not reduce short-term mortality or incidence of VAP. Findings on the secondary outcomes demonstrated no difference in long-term mortality. Early tracheostomy did not shorten the duration of mechanical ventilation or sedation. Likewise, early tracheostomy was not associated with shorter ICU or hospital stay. There were no significant differences among the complications examined in the meta-analysis.
This well-done systematic review and meta-analysis provides a very coherent presentation on the topic. For those clinicians new to meta-analysis, a review of processes and terms is warranted to inform the reader. Any meta-analysis needs to begin with a thorough, high-quality systematic review. The purpose of a systematic review is to provide a comprehensive summary of literature relevant to a specific topic or research question. Meta-analysis can be defined as the integration of findings across studies. A variety of statistical procedures are used to integrate and summarize these findings depending on the purpose and level of data under consideration (continuous, dichotomous, etc). The authors of this meta-analysis used the relative risk (RR) statistic to report the pooling of results from seven RCTs. RR is the risk of an event occurring given one condition vs the risk of it occurring given a different condition. In this meta-analysis, the findings consistently demonstrated no difference in the events or clinical outcomes occurring in either group. For the interested reader, many excellent meta-analyses and resources are available on a variety of topics from the Cochrane Collaboration (www.cochrane.org).
Of great importance from this meta-analysis is that there is no consistent definition of early (2-8 days) or late (14-28 days) tracheostomy placement. This lack of agreement and consistent definition makes comparisons among trials extremely challenging. The reader is advised to carefully consider the definitions of early and late tracheostomy reported in individual studies and what types of patient populations and their clinical characteristics are included in the respective trials.
The overall findings of the meta-analysis reported by Wang and colleagues question the perceived benefits of early tracheostomy, particularly in light of the placement procedure not being risk-free. Of great challenge to clinicians is that there is no validated formula to determine which patients might benefit the most from early tracheostomy, despite the belief that tracheostomy should provide some benefit to patients, such as improved comfort. However, given that patient comfort is rarely if ever assessed, clinicians are advised to assess comfort and quality of life in patients requiring long-term ventilatory support to determine if patients themselves receive actual benefit following this procedure. Given that the optimal timing of tracheostomy was not clearly determined by the findings reported in this paper, clinicians are urged to consider factors of importance to patients in their decision making regarding tracheostomy placement.