By Bradley Dean
Following the 2013 death of Drew Hughes, a lawsuit was filed alleging the hospital and/or its employees, “failed to keep Drew Hughes properly sedated and restrained; failed to properly re-intubate Andrew Davis Hughes during the transport; failed to perform standard objective tests to verify proper placement of the endotracheal tube; failed to recognize clear signs and symptoms of an esophageal intubation and respond to those signs….”
Three years after Hughes’ death, his family continues to push forward, knowing their beloved son will never return.
Hughes did not die from a failure of intubation, but rather from a failure of oxygenation.
It is essential that providers recognize incorrect tube placement in the esophagus or hypopharynx in order to prevent the subsequent development of progressive hypoxemia that leads to irreversible organ damage or death.
Airway compromise has been identified as a preventable cause of poor outcomes and death in trauma and cardiac arrest patients for many years, and was published numerous times prior to Hughes’ death [1, 2].
Pull out the tube and ventilate
Unsuccessful or poorly conducted endotracheal intubation can be life-threatening. It may result in significant complications, such as esophageal intubation, hypoxemia or post-induction cardiac arrest [3, 4, 5].
Recognition of incorrect airway placement is important to avoid hypoventilation, hypoxia and potential gastric insufflation, which can result in regurgitation and aspiration.
Signs of incorrect placement should be actively sought before concluding the artificial airway is correctly placed. The provider must have a plan and must be prepared.
If you have any doubt about tube placement, pull out the tube and ventilate the patient.
At the time of Hughes’ injury and intrafacility transport by ambulance, rapid sequence induction was generally accepted as the technique of choice for securing the airway in seriously ill or injured patients. The guideline in North Carolina at the time for minimum standards for use in all intubated patients included the use of waveform capnography. End-tidal carbon dioxide is measured directly and continuously throughout the respiratory cycle and accurately reflects the arterial carbon dioxide tension in patients.
Intubation confirmation
Should the initial intubation technique prove to be unsuccessful, change something —different size or type of blade, different size tube or a different provider. Multiple repetitions of the same failing technique leads to further failures and increases the likelihood of a “can’t intubate, can’t ventilate” scenario.
There are four criteria to be certain that a tracheal tube is correctly placed:
- The endotracheal tube is seen passing through the vocal cords (direct laryngoscopy).
- Chest observation shows bilateral and equal expansion.
- Bilateral air entry on auscultation of the chest in the axillae is present.
- Capnography displays a characteristic, continuous non-decaying waveform.
Some additional indicators, which may assist in confirming correct placement of the tracheal tube, but are not definitive, include:
- Misting or condensation in the tracheal tube on exhalation.
- Appropriate airway pressure, tidal volume and spirometry trace.
Esophageal placement
An incorrectly placed tracheal tube is positioned in one of two locations, the esophagus or the bronchus, usually the right. Each location presents a specific diagnosis and requires a particular response from the provider.
At all times, the message remains the same. Patients do not die from failure to intubate, but failure to oxygenate. When in doubt, pull out the tube.
Reliable signs of esophageal intubation:
- Absent or decaying capnography waveform.
- Progressive hypoxia that may take three minutes or more for onset depending on pre-oxygenation levels.
- Abnormal sounds heard in the axilla or epigastrium.
Additional clues of esophageal intubation:
- Absent bilateral chest expansion.
- Poor compliance to ventilation.
- Abdominal distension.
- Absent normal breath sounds over lung fields.
- Sound of gas regurgitated from esophagus.
If esophageal intubation is not recognized early, it may present as cardiovascular abnormalities or collapse, making the diagnosis much more difficult. Always maintain a high index of suspicion of esophageal intubation, particularly if the intubation was difficult. If in doubt, pull out the tube and do the following:
- Bag-mask ventilation with an oropharyngeal or nasopharyngel or both.
- Administer high concentration of oxygen using bag-mask ventilation and a high-flow nasal cannula if possible.
- Call for assistance from other providers.
- Prepare for laryngoscopy and re-intubation when the patient is stable and the team is ready.
- Consider inserting a supraglottic airway.
Following the reintubation of Hughes, the crew never used objective testing, such as capnography, to verify the endotracheal tube was properly placed. Soon after the re-intubation attempt, Hughes’ heart rate began to drop and the crew could not find a pulse. He became pulseless and cyanotic, with no fogging of the endotracheal tube. Even without the use of capnography, these are signs of an esophageal intubation that were not recognized.
Bronchial placement
In the event that the patient is intubated but the tube is advanced too far, oxygenation may not be appropriate because the tube is isolated to a single bronchus. Most often this will be the right main bronchus because it has a less acute angle than the left. Reliable signs of bronchial intubation include:
- Uneven chest expansion.
- Reduced breath sounds unilaterally, which can be subtle.
- High airway pressures.
Additional clues:
- Decaying, but stabilizing waveform capnography that remains consistent with generally normal waveform.
- Oxygen desaturation to around 85-88 percent, which may take several minutes.
When bronchial intubation occurs, the patient physiologically loses ventilation and pressure to the other lung. This may result in alveolar collapse to the non-ventilated lung and overinflation of the directly ventilated lung, potentially causing a pneumothorax and mediastinal shift. When you suspect bronchial isolation, take the following steps:
- Administer high concentration oxygen.
- Observe the chest and auscultate both axilla.
- Withdraw the tracheal tube, with cuff deflated, until breath sounds are heard bilaterally.
- Ensure adequate re-expansion of the non-ventilated lung. This will usually require positive-end expiratory pressure and, if using a ventilator, bag-mask ventilations.
- If at any point you believe that the tracheal tube has been removed from the trachea, pull out the tube.
Prehospital intubation is a high-risk, low-frequency procedure that done correctly may be lifesaving, but is deadly when performed incorrectly. As a provider you should practice your skills and sequences often. Any skill that is seldom performed should have a corollary increase in the frequency of training.
References:
1. Anderson ID, Woodford M, de Dombal FT, Irving M: Retrospective study of 1000 deaths from injury in England and Wales. BMJ 1988, 296:1305-1308.
2. Esposito TJ, Sanddal ND, Hansen JD, Reynolds S: Analysis of preventable trauma deaths and inappropriate trauma care in a rural state. J Trauma 1995, 39:955-962.
3. Wirtz DD, Ortiz C, Newman DH, Zhitomirsky I: Unrecognized misplacement of endotracheal tubes by ground prehospital providers. Prehosp Emerg Care 2007, 11:213-218.
4. Davis DP, Dunford JV, Poste JC, Ochs M, Holbrook T, Fortlage D, Size MJ, Kennedy F, Hoyt DB: The impact of hypoxia and hyperventilation on outcome after paramedic rapid sequence intubation of severely head-injured patients. J Trauma 2004, 57:1-8; discussion 8-10.
5. Bermard SA, Nguyen V, Cameron P, Masd K, Fitzgerald M, Cooper DJ, Walker T, Std BP, Myles P, Murray L, Taylor D, Smith K, Patrick I, Edington J, Bacon A, Rosenfeld JV, Judson R: Prehospital rapid sequence intubation improves functional outcome for patients with severe traumatic brain injury: a randomized controlled trial. Ann Surg 2010, 252:959-965.