Verification of Endotracheal Tube Placement

This Policy Resource and Education Paper is an explication of the Policy Statement Verification of Endotracheal Tube Placement.

Introduction

The purpose of this paper is to identify the medical literature that pertains to verification of endotracheal tube placement in the emergency department and out-of-hospital settings.

This PREP is an update of a previous PREP from 2001 with the same title, Verification of Endotracheal Tube Placement.

There have been additional publications on this topic since the 2001 policy statement and PREP. For this update, a literature search was performed and articles were systematically graded. Articles used for the formulation of the policy statement are included in the Evidentiary Table that appears later in this document.

All articles were graded by at least 2 subcommittee members for strength of evidence and classified by the subcommittee members into 3 classes of evidence on the basis of the design of the study, with design 1 representing the strongest evidence and design 3 representing the weakest evidence for therapeutic, diagnostic, and prognostic clinical reports, respectively (Appendix A). Articles were then graded on 6 dimensions thought to be most relevant: blinded versus nonblinded outcome assessment, blinded or randomized allocation, direct or indirect outcome measures (reliability and validity), biases (eg, selection, detection, transfer), external validity (ie, generalizability), and sufficient sample size. Articles received a final grade (Class I, II, III) on the basis of a predetermined formula taking into account design and quality of study (Appendix B). Articles with fatal flaws were given an "X" grade.

In the course of reviewing the body of literature for this question, the committee reviewed a large number of investigations that tested various devices and techniques in the setting of the operating room (anesthetized, paralyzed, fasted adults) or the delivery room (neonatal resuscitation). Although these studies tended to have good intrinsic quality, the committee did not consider these studies (were assigned "X" grade) because of problems generalizing the results of these studies to the emergency department and out-of-hospital settings.

Discussion

1. Improper placement of endotracheal tubes into the esophagus ("esophageal intubation"), can remain undetected despite physical examination, chest radiography, and pulse oximetry methods that seem to confirm proper tube placement.^1-7 For this reason, an additional method should be used to verify correct initial placement of the endotracheal tube.
   

2. No single technique used for confirmation of endotracheal tube placement has been proven to be 100% accurate.^1-7 While visualization of the endotracheal tube passing through the vocal cords represents the primary method for assessing initial endotracheal tube placement, objective confirmation of proper placement is necessary.
   

3. Methods of endotracheal tube position assessment include repeat direct laryngoscopy, qualitative and quantitative end-tidal carbon dioxide detection, esophageal detector devices, and more recently, ultrasound utilization and transthoracic impedance.^8-21 
   

4. End-tidal carbon dioxide detection, using either qualitative or quantitative methods, approaches 100% sensitivity and specificity in the patient with spontaneous circulation.^3,5,7,10,11
   

5. Assessment of endotracheal tube position by detection of exhaled carbon dioxide is less reliable in patients with poor circulatory perfusion conditions, particularly cardiac arrest patients. In these patients, delivery of carbon dioxide to the lungs may be insufficient to produce a reliable confirmation of tube placement. Essentially all reported false negative (endotracheal tube in the trachea with no detection of exhaled carbon dioxide) events of carbon dioxide detection in intubated patients have been observed in the setting of a low perfusion state, including cardiac arrest patients or those in extensive pulmonary edema.^8-13 In these patients, an alternative method of confirming endotracheal tube placement may be required.
   

6. Esophageal detector devices have some utility as a technique for endotracheal tube position assessment. While these devices are often inexpensive and have generally demonstrated good utility in detecting esophageal intubations, inaccurate findings can result in obese patients, those with a large amount of air in the esophagus or stomach, and in patients with copious pulmonary secretions.^14-16 In addition, esophageal detector devices do not provide the possibility for ongoing assessment of continued proper tube location.
   

7. Ultrasound imaging and transthoracic impedance methods offer potential as techniques that may prove to be helpful as adjuncts to detect and monitor the proper location of endotracheal tubes.^17-21 The evidence is currently insufficient to endorse widespread implementation of these technologies for this purpose.
   

8. Endotracheal tubes that are initially placed into the trachea may be dislodged during patient movement or patient transport. Given the frequency of movements and transport, particularly in the emergency setting, tube position should be frequently reassessed. Continuous endotracheal tube monitoring is recommended to assure prompt detection of endotracheal tube dislodgement from the trachea. If equipment to continuously monitor endotracheal tube position is not available, at a minimum, endotracheal tube placement should be reconfirmed promptly if the patient’s condition deteriorates.

Summary

Verification of proper endotracheal tube location should be performed for all patients at the time of the initial intubation effort(s). Chest and abdomen auscultation, pulse oximetry, chest radiography and esophageal detector devices are not comparable to end-tidal carbon dioxide assessment for the verification of endotracheal tube placement in patients who have adequate tissue perfusion. Endotracheal tube location re-assessment should be performed whenever patient movement, clinical interventions, or clinical conditions suggest the possibility of tracheal tube dislodgement.

Revised by a subcommittee of the Clinical Policies Committee
John H. Burton, MD, FACEP
J. Stephen Huff, MD, FACEP
Eric J. Lavonas, MD, FACEP, FACMT, Chair 

References

1. American Heart Association. 2005 American Heart Association (AHA) Guidelines Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular Care (ECC) of Pediatric and Neonatal Patients: Pediatric Basic Life Support. Pediatrics. 2006;117:e989-1004.
   
2. The International Liaison Committee on Resuscitation. The International Liaison Committee on Resuscitation (ILCOR) consensus on science with treatment recommendations for pediatric and neonatal patients: pediatric basic and advanced life support. Pediatrics. 2006;117:e955-e977.
   
3. Salem MR. Verification of endotracheal tube position. Anesthesiol Clin North America. 2001;19:813-839.
   
4. Wagner CM. Verification of pediatric endotracheal tube placement. Air Med J. 2003;23:10-12.
   
5. Grmec S. Comparison of three different methods to confirm tracheal tube placement in emergency intubation. Intensive Care Med. 2002;28:701-704.
   
6. Grmec S, Mally S. Prehospital determination of tracheal tube placement in severe head injury. Emerg Med J. 2004;21:518-520.
   
7. Takeda T, Tanigawa K, Tanaka H, et al. The assessment of three methods to confirm tracheal tube placement in the emergency setting. Resuscitation. 2003;56:156-157.
   
8. Bhende MS, LaCovey DC. End-tidal carbon dioxide monitoring in the prehospital setting. Prehosp Emerg Care. 2001;5:208-213.
   
9. Bhende MS. End-tidal carbon dioxide monitoring in Pediatrics – Clinical Applications. J Postgrad Med 2001;47:215-218.
   
10. Donald MJ, Paterson B. End tidal carbon dioxide monitoring in prehospital and retrieval medicine: a review. Emerg Med J. 2006;23:728-730.
    
11. George S, Macnab AJ. Evaluation of a semiquantitative CO2 monitor with pulse oximetry for prehospital endotracheal tube placement and monitoring. Prehosp Disast Med. 2002;17:38-41.
    
12. Zar HA, Wu WW. The inability to detect carbon dioxide after endotracheal intubation as a result of one-way valve obstruction of the endotracheal tube. Anesth Analg. 2001;93:971-972.
    
13. Li J. Capnography alone is imperfect for endotracheal tube placement confirmation in emergency intubation. J Emerg Med. 2001;20:223-229.
    
14. Hendey GW, Shubert GS, Shalit M, Hogue B. The esophageal detector bulb in the aeromedical setting. J Emerg Med. 2002;23:51-55.
    
15. Tanigawa K, Takeda T, Goto E, et al. The efficacy of esophageal detector devices in verifying tracheal tube placement: a randomized cross-over study of out-of-hospital cardiac arrest patients. Anest Analg. 2001;92:375-378.
    
16. Li J. A prospective multicenter trial testing the scoti device for confirmation of endotracheal tube placement. J Emerg Med. 2001;20:231-239.
    
17. Sustic A. Role of ultrasound in the airway management of critically ill patients. Crit Care Med. 2007;35:s173-s177.
    
18. Galicinao J, Bush AJ, Godambe SA. Use of bedside ultrasonography for endotracheal tube placement in pediatric patients – a feasibility study. Pediatrics. 2007;120:1297-1303.
    
19. Hsieh KS, Lee C, Lin C, et al. Secondary confirmation of endotracheal tube position by ultrasound image. Crit Care Med. 2004;32:s374-s377.
    
20. Kramer-Johansen J, Eilevstjonn J, Olasveengen TM, et al. Transthoracic impedance as a tool to detect malpositioned tracheal tubes. Resuscitation. 2008;76:11-16.
    
21. Pytte M, Olasveengen TM, Steen PA, et al. Misplaced and dislodged endotracheal tubes may be detected by the defibrillator during cardiopulmonary resuscitation. Acta Anaesthiol Scand. 2007;51:770-772.

EVIDENTIARY TABLE

AHA, American Heart Association; CO₂, carbon dioxide; ED, emergency department; EDD, esophageal detector device; EMS, emergency medical services; ET, endotracheal tube; ETCO₂, end-tidal carbon dioxide; ICU, intensive care unit; ILCOR, International Liaison Committee on Resuscitation; LED, light-emitting diode; SCOTI, sonomatic confirmation of tracheal intubation; y, year;

Appendix A. Literature classification schema.*

*Some designs (eg, surveys) will not fit this schema and should be assessed individually.
^†Objective is to measure therapeutic efficacy comparing >2 interventions.
^‡Objective is to determine the sensitivity and specificity of diagnostic tests.
^§Objective is to predict outcome including mortality and morbidity.

Appendix B. Approach to downgrading strength of evidence.