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

Study

Year

Design

Intervention(s)/Test(s)/Modality

Outcome Measure/Criterion Standard

Results

Limitations/Comments

Class

AHA guidelines1

2005

Consensus statement

 

 

Consensus statement from the AHA promoting the use of tube verification methods, particularly exhaled CO2, beyond clinical observation in pediatric patients

Consensus statement

III

ILCOR2

2006

Consensus statement

 

 

Consensus statement from ILCOR for Pediatric Basic and Advance Life Support; recommended exhaled CO2 for confirmation of tracheal tube placement and during transport; EDD may be considered for children >20 kg to confirm tracheal tube placement

Consensus statement

III

Salem3

2001

Review article

 

 

Review article discussing commonly prescribed methods of confirming ET placement

Review article

III

Wagner4

2004

Review article

 

 

Review article discussing commonly prescribed methods of confirming ET placement in pediatric patients

Review article

III

Grmec5

2002

Prospective observational study in adult prehospital patients

Capnometry – immediate; capnography; auscultation

Repeat laryngoscopy

Cardiac arrest patients: capnometry:

88% sensitivity/100% specificity; capnography:

100% sensitivity/100% specificity; auscultation: 100% sensitivity/80% specificity;

Noncardiac arrest patients: capnometry: 100% sensitivity/100% specificity; capnography: 100% sensitivity/100% specificity; auscultation:

94% sensitivity/83% specificity

Physicians performed test; intubator read the ETCO2 device – not fully blinded

I

Grmec and Mally6

2004

Prospective observational study in adult head injured patients

Capnometry – immediate;

capnometry – 6th breath;

capnography;

auscultation

Repeat laryngoscopy

Head injured patients: capnometry immediate: 100% sensitivity/100% specificity;

capnography 6th breath: 100% sensitivity/100% specificity;

capnography: 100% sensitivity/100% specificity;

auscultation: 94% sensitivity/66% specificity

Setting: prehospital (ground), but physicians performed test; intubator read the ETCO2 device – not fully blinded; probably a subset of Grmec 2002

I

Takeda et al7

2003

Prospective, observational study in out-of-hospital cardiac arrest patients

 

Bulb EDD, ETCO2, auscultation

Clinical assessment

ETCO2 superior to EDD in patients with circulation;

auscultation superior in cardiac arrest patients

Patients intubated in the ED; criterion standard flawed

III

Bhende and LaCovey8

2001

Review article

 

 

Review article discussing ETCO2 monitoring in the prehospital setting

Review article

III

Bhende9

 

2001

Review article

 

 

Review article discussing ETCO2 monitoring in pediatric patients

Review article

III

Donald and Paterson10

2006

Review article

 

 

Review article discussing ETCO2 monitoring in the prehospital setting

Review article

III

George and Macnab11

 

 

 

2002

Prospective observational case series in out-of-hospital patients

Capnometry

Clinical assessment

Descriptive report on a semiquantitative ETCO2 device used in transport patients for continuous monitoring as well as initial ET placement assessment

Design; small numbers; criterion standard not independent

III

Zar and Wu12

2001

Case report of a single patient

Continuous ETCO2 analyzer

Clinical assessment

Patient with continuous ETCO2 analyzer in whom mucus plug made ETCO2 unreliable

Single case report

III

Li J13

 

 

 

2001

Meta-analysis of capnography trials in ED populations; retrospective analysis of a large emergency intubation database

Assessment of ETCO2 for confirmation of ET placement in the ED population as published in previous trials

Multiple methods used in each study to assess ET placement

Assessment of ETCO2 for confirmation of ET placement in the ED population as published in previous trials; 10 trials met inclusion criteria for analysis; capnography calculated to have aggregate sensitivity of 93% and specificity of 97%

Design; multiple methods used in each study to assess ED placements

III

Hendey et al14

 

 

2002

Prospective observational study of aeromedical patients

EDD

Capnometry, oxygen saturation, clinical assessment

EDD found to have 80 sensitivity/97 specificity in the detection of esophageal intubation

Design; criterion standard not blinded

II

Tanigawa et al15

2001

Prospective, observational crossover study of out-of-hospital cardiac arrest patients

Syringe EDD, bulb EDD, ETCO2

Clinical assessment

Syringe EDD and bulb EDD found to have sensitivity of 73% and 71% respectively, for detection of tracheal intubation

Small sample size;

criterion standard flawed

III

Li J16

 

 

 

2001

2 phase prospective descriptive study: initial feasibility phase in a prospective series of elective surgical patients; second phase in a prospective convenience sample of intubated ED patients

SCOTI evaluated for ET in emergency and elective surgical intubated patients; this device is an EDD with a variety of LED displays

Anesthesiologist or emergency physician assessment of ET by one or many of multiple methods, including ETCO2, auscultation, direct visualization, EDD, and chest radiograph findings

SCOTI correctly identified 205 of 220 tracheal placements and 102 of 103 esophageal placements for sensitivity of 93% and specificity of 98%

Population limited to older children and adults due to less reliability in SCOTI device in endotracheal tubes less than size 6; no standardized assessment routine used for ET placement assessment; nonblinded data collection

III

Sustic17

2007

Review article

 

 

Review of ultrasound potential use in airway emergencies

Review article

III

Galicinao et al18

2007

Prospective observational study, pediatric ICU patients in phase 1, ED patients in phase 2

Ultrasound – cricothyroid membrane, capnometry

Clinical assessment, chest radiograph

Utility of bedside ultrasonography in a pediatric population assessed. 49 patients in phase 1, 50 in phase 2; ultrasound images found to yield accurate and rapid assessment

Design; nonblinded; chest x-ray utilized as criterion standard

Phase I: X

 

Phase 2: II

Hsieh et al19

 

 

 

2004

Prospective observational case series of pediatric patients in the pediatric ICU

Assessment of ET placement by ultrasound imaging of diaphragm movement;

Clinical assessment; all placements confirmed with auscultation; only initial placements confirmed with ETCO2

Pediatric patients newborn to 17 y enrolled and intubated; ultrasound identified 2 of 2 esophageal intubations and 8 of 8 right mainstem intubations; all correct endotracheal placements demonstrated normal ultrasound imaging

Pediatric patients only; patients with comorbid disease(s) affecting diaphragm motion not included and may limit this technology application to all patients

III

Kramer-Johansen et al20

2008

Prospective observational feasibility study in out-of-hospital cardiac arrest patients in whom resuscitation efforts had been ceased due to futility of further efforts

Transthoracic impedance changes were measured across the chest with standard defibrillation pads in order to surmise the difference in impedance between tracheal and esophageal ETs

Direct visualization of ET placement by investigator; capnography used in many patients

123 esophageal and 178 tracheal ETs were evaluated in 9 patients; impedance changes above 1.2 ohms were 100% specific and 69% sensitive for tracheal intubation

A derivation dataset limited to recently deceased cardiac arrest patients; application to the ED population at large as well as validation remain issues

III

Pytte et al21

2007

Case reports from 2 adult cardiac arrest patients

Report of continuous monitoring of transthoracic impedance during cardiopulmonary resuscitation;

ET placement confirmed by auscultation

Absence of ventilation-induced changes in transthoracic impedance suggest complications or misplacement of the ET

Design; small number of patients

III

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.*

 Design/Class

Therapy†

Diagnosis‡

Prognosis§

 1

Randomized, controlled trial or meta-analyses of randomized trials

Prospective cohort using a criterion standard

Population prospective cohort

 2

Nonrandomized trial

Retrospective observational

Retrospective cohort

Case control

 3

Case series

Case report

Other (eg, consensus, review)

Case series

Case report

Other (eg, consensus, review)

Case series

Case report

Other (eg, consensus, review)

*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. 

Downgrading

 1 

 2 

3

None   I  II  III 
1 level

II

III

X

2 levels   III  X  X
Fatally flawed   X  X  X
       

 

 

 

 

 
 
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