This document discusses using ultrasound to confirm endotracheal tube placement. It states that ultrasound is a simple, fast, and reliable adjunct technique that can be used when other confirmation methods like capnography are unreliable or not available. There are two ultrasound techniques described - direct (transtracheal) ultrasound looks inside the trachea or esophagus to see if the tube is correctly placed, while indirect (transthoracic) ultrasound looks for movement of the pleura indicating lung ventilation. Ultrasound is not meant to replace capnography and auscultation but can be a helpful additional method in emergency situations or for patients who are not responding as expected after intubation. The document provides details on how to

1. Ultrasound confirmation of
endotracheal tube placement
Dr James Wheeler BSc MBBS FACEM DDU
Emergency Physician, SCGH
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2. Will this replace traditional
methods of ETT confirmation?
• Specifically, does this replace capnography and
auscultation
• NO!
• BUT:
• No single confirmatory method is entirely reliable esp. in
emergency situations, and
• In certain circumstances US confirmation can be a very
helpful adjunct

3. Why would you do it?
• Transtracheal ultrasound is a relatively SIMPLE technique
• FAST (~8 sec vs 18 sec for capnography1)
• May be more reliable than capnography changes in certain patient groups?
• SENSITIVE and SPECIFIC 2,3,4
• The pooled sensitivity and specificity for the detection of proper ETT placement
with US were:
• Sensitivity: 98% (95% C.I. 97-99%); Specificity: 98% (95% C.I. 95-99%);
PPV: 99.5%, NPV: 93.8%
• Does not require ventilations to assess tube placement
• May prevent gastric insufflation and delay in diagnosis of misplacement

4. When would you use it?
• When ETCO2 unreliable (or not available?)
• Cardiac arrest / massive PE
• Emergency blind intubation / predicted difficult intubation
• Patient arrives intubated and requires rapid confirmation of
ETT placement
• Any patient not responding as expected after ETT
placement prior to attempting re-intubation

5. How do you do it?
Direct (Transtracheal)
• Looking for evidence of direct endotracheal intubation OR
oesophageal intubation (a “second trachea”)
• During intubation OR Post-intubation
Indirect (Transthoracic)
• Looking at the pleural space for evidence of lung ventilation
(pleural movement)
• Post-intubation

6. Direct: Technique
Probe:
• high frequency (6-12MHz) linear probe (but
can use lower freq micro convex or
curvilinear in obese)
Preset:
• Superficial, depth sufficient to see posterior
to trachea, focal zone at trachea
Probe placement:
• In transverse plane just above the
suprasternal notch
• i.e. beneath cricoid

7. Direct: Technique
Endotracheal intubation:
• One air-mucosal interface
• Hyperechoic reverberation artefacts inside trachea
OR
Oesophageal intubation:
• Dynamic opening of the oesophagus by the ETT seen on US performed during laryngoscopy
• Two air-mucosal interfaces (“two tracheas” , “double track sign”)
• Hyperechoic reverberation artifacts inside oesophagus
May also interrogate cuff position by infiltrating saline

8. Direct: US Anatomy

9. Direct: Tracheal Intubation

12. Direct - Oesophageal Intubation

18. Indirect
• Looking at the pleural space for evidence of lung
ventilation (pleural movement)
• Differential pleural movement may indicate RMS
intubation
• Requires ventilation

19. Indirect US Anatomy

20. Indirect: Ventilating Lung

21. Indirect: Non-Ventilating Lung

22. Indirect: Pneumothorax

23. Indirect: Pneumothorax
(Lung Point)

24. Pitfalls?
• Requires access to US machine
• No single confirmatory method is entirely reliable (esp. in
emergency situations)
• Operator dependent
• Surgical emphysema may obscure view
• Can’t identify supraglottic airway
• Pneumothorax (for indirect)

25. References
1. Reliability of Ultrasonography in Confirming Endotracheal Tube
Placement in an Emergency Setting. Vimal Koshy, Thomas et al.
Indian J Crit Care Med. 2017 May; 21(5): 257–261.
2. Transtracheal ultrasound for verification of endotracheal tube
placement: a systematic review and meta-analysis. Das SK1, Choupoo
NS, Haldar R, Lahkar A. Can J Anaesth. 2015 Apr;62(4):413-23
3. Ultrasonography for confirmation of endotracheal tube placement: A
systematic review and meta-analysis. Eric H.Chou et al. Resuscitation,
Volume 90, May 2015, 97-103
4. Can Transtracheal Ultrasonography Be Used to Verify Endotracheal
Tube Placement? Gottlieb M, Bailitz J .Ann Emerg Med. 2015 Oct;
66(4): 394-5