Tracheostomy in the Intensive Care Unit

Tracheostomy in the Intensive Care Unit

A 47-year-old male was admitted to the intensive care unit (ICU) following a high-speed motorcycle accident. He had a number of injuries including bilateral pneumothoraces, multiple spinal fractures, an open-book pelvis fracture, and a brachial plexus injury. Bilateral chest drains were inserted and external fixation of the pelvis was performed. The patient was extubated eventually at day 15 but required reintubation within 12 hours because of a poor cough and sputum retention 

What are the indications for a tracheostomy and when shout it be considered?

Dave Slessor

The classical indication for a tracheostomy was upper airway obstruction (1). Other indications include to facilitate weaning from mechanical ventilation (MV), protecting the airway in patients who are high risk for aspiration, and to facilitate the removal of bronchial secretions when there is poor cough effort with sputum retention (1).

One of the advantages of a tracheostomy, compared with an endotracheal tube (ETT), is that by bypassing the upper airways the anatomical dead space can be reduced by up to 50% (1). This decreases the work of breathing, which can aid weaning. A tracheostomy is normally more comfortable for patients than an ETT. This means sedation can often be decreased or stopped which can also aid weaning (1). One of the disadvantages of a tracheostomy is that the warming and filtration that occurs in the upper airways is lost leading to thicker secretions that can cause obstruction (1).

Timing of Tracheostomy

A number of studies have investigated at what point during an ICU stay that a tracheostomy should be performed. Young completed a meta-analysis of 406 patients comparing early tracheostomy (ET) vs. late tracheostomy (LT) using a cut-off at ≤7 and >7 days respectively (2). ET significantly reduced the duration of MV (DMV) (weighted mean difference -8.5 days, 95%C.I. -15.3 to -1.7 days, P=0.03) and ICU-length of stay (LOS) (-15.3 days, -24.6 to -6.1, P=0.001). There was no difference in mortality. However, of the randomised controlled trials (RCT) included, the study that showed the greatest improvement with ET had severe methodological flaws. This RCT reported that DMV was reduced (12 vs. 32 days, P<0.05) with ET (≤7 days) compared to LT (>7 days) in 106 multiple trauma patients (3). 120 patients were excluded as they were extubated without the need for a tracheostomy. If these patients had been included a number would have had an ET, that they did not require, and had the risks associated with the procedure. Another flaw of the study was that pseudo-randomisation was used based on the day of admission. Allocation concealment was therefore not maintained. This is of particular importance in this study as patients were only included after they had undergone a tracheostomy. Therefore any biases that staff had may have influenced the decision to perform a tracheostomy and thereby include the patient in the study.

More recently the TracMan study was completed, a high quality multi-centre RCT on 909 patients that compared ET (day 1-4) versus LT (≥day 10) (4). Patients were included if they were felt to require at least seven days of ventilation. There was no difference in mortality or ICU-LOS. Of note 53.7% of patients randomised to the LT group did not receive a tracheostomy. Of these 36.5% had been discharged from ICU and a further 32% no longer required MV. This demonstrates the difficulties in predicting who will require prolonged ventilation.

Specific populations

Studies have looked at specific populations to determine if certain subgroups benefit from an early or LT.

In 2009 EAST recommended that patients with a severe head injury receive an ET as they stated it decreased the DMV and ICU stay (5). Of the studies used to make this recommendation only two were RCT that had a positive outcome for an ET. There are concerns regarding the internal validity of both of these studies. The first was the Rodriguez study that was described previously (3). The second reported a significant decrease in DMV when an ET (day five/six) was performed compared to prolonged ventilation in 62 patients with severe head injuries (14.5±7.3 vs. 17.5± 10.6, P=0.02) (6). However, it appears the statistics have been incorrectly calculated as when the author of this summary repeated the test the wide standard deviation made the result non-significant. On contacting the author of the RCT it was found that the trial data has been lost and therefore the accuracy of the results cannot be verified.

It has been recommended, based on expert opinion only, that patients with acute spinal cord injury who are likely to have prolonged MV should have an ET (7). In this population, a retrospective study has demonstrated a reduced DMV and ICU-LOS in patients treated with an ET compared to a LT (8). However, as this was a non-randomised study there may be unexplained confounding variables that account for the results found. Nonetheless, in this group of patients it may be possible to predict who will require prolonged MV and therefore who will benefit from an ET.

Technique

Traditionally a surgical approach was used for tracheostomies. A percutaneous technique has been introduced with the argument that a minimally invasive procedure results in less tissue damage, bleeding and infection (9). It can also be performed easily at the bedside minimising any risks from transporting a patient to the operating room (OpR). A meta-analysis, including 1212 patients, compared percutaneous tracheostomy (PT) with surgical tracheostomy (ST) (9). There was no significant difference in mortality or bleeding. However, wound infections rates were significantly lower in the PT than the ST group (Odds ratio 0.28 95% Confidence Interval [C.I.] 0.16-0.49, P<0.0005). A sub-group analysis demonstrated a significantly lower mortality in the PT group compared with patients who had a ST done in the OpR (Odds ratio 0.71, 95% C.I. 0.5-1, p=0.05). Reasons they suggest for this difference include the reduction in infection and the avoidance of transport complications. However, with multiple sub-group analyses performed we have to be wary that this may be a type 1 error. Most of the studies analysed in the meta-analysis excluded patients with challenging anatomy or coagulopathies thereby limiting the generalizability of the results.

Complications

Tracheostomy related complications occur in 6.3% of patients (4). In four years there were 1700 incidents reported to the National Patient Safety Agency regarding tracheostomies including 30 deaths (1). Complications can be classified according to their stage of presentation (1):

  • Immediate: haemorrhage, misplacement of tube, pneumothorax, loss of the upper airway
  • Delayed (≤7 days post-procedure): tube blockage/displacement, infection, trachea-oesophageal fistula, haemorrhage
  • Late (>7 days post-procedure): tracheal stenosis, haemorrhage

References

  1. NTSP Manual www.tracheostomy.org.uk 2013.
  2. Griffiths J, Young JD. Systematic review and meta-analysis of studies of the timing of tracheostomy in adult patients undergoing artificial ventilation. bmj. 2005;330(7502):1243.
  3. Rodriguez JL, Flint LM. Early tracheostomy for primary airway management in the surgical critical care setting. British Journal of Surgery. 1990;77(12):1406-10.
  4. Young D. Effect of early vs late tracheostomy placement on survival in patients receiving mechanical ventilation: The tracman randomized trial. JAMA. 2013;309(20):2121-9.
  5. Holevar M, Ebert JB, et al. Practice management guidelines for timing of tracheostomy: the EAST Practice Management Guidelines Work Group. The Journal of Trauma and Acute Care Surgery. 2009;67(4):870-4.
  6. Bouderka MA, Harti A. Early tracheostomy versus prolonged endotracheal intubation in severe head injury. The Journal of Trauma and Acute Care Surgery. 2004;57(2):251-4.
  7. Wing P, Alvarez E. Early acute management in adults with spinal cord injury. A clinical practice guideline for health-care professionals. J Spinal Cord Med. 2008;31(4):408-79.
  8. Romero J, Oliviero A. Tracheostomy timing in traumatic spinal cord injury. European Spine Journal. 2009;18(10):1452-7.
  9. Delaney A, Nalos M. Percutaneous dilatational tracheostomy versus surgical tracheostomy in critically ill patients: a systematic review and meta-analysis. Critical Care. 2006;10(2):R55.

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