This chapter will review the various methods utilized to confirm appropriate endotracheal (ET) intubation. Direct visualization of the ET tube passing through the vocal cords is the preferred method for the initial assessment of a properly placed airway. Unfortunately, this is not always feasible. Rates for incorrect ET tube placement have been noted to be up to 25%.1,2 The verification of correct ET tube placement is as or more important than the intubation procedure. Lack of proper confirmation of ET tube placement has the potential for serious patient harm and catastrophic outcomes if unrecognized and uncorrected.
For approximately 20 years, there has been ongoing research and development to improve upon the basic techniques of physical examination confirmation of ET intubation. Physical examination with auscultation has been found to be inadequately sensitive (94%) and specific (83%) as an independent method for confirmation of correct ET tube placement.3 This chapter discusses the use of physical exam findings, esophageal detection devices (syringe and bulb), carbon dioxide (CO2) detection devices (a qualitative detector and a continuous quantitative monitor), and imaging techniques (radiography and ultrasound). Each method is described for a patient with normal anatomy and the absence of any pathology (e.g., neck or chest trauma). While all these methods can be used in all patients, certain patient conditions or pathology may affect the accuracy of some methods. No single method is universally or completely reliable, obviating the need for a multiple method approach. This multiple method approach to confirmation of ET intubation is now the accepted practice according to The American College of Emergency Physicians (ACEP) Board of Directors policy statement as of April 2009.4
Since the advent of ET intubation, the use of physical examination methods has been the mainstay for the initial evaluation of proper ET tube placement. Direct visualization of the insertion of the ET tube through the vocal cords and into the trachea is the first method to confirm proper ET tube placement. Postintubation direct visualization of the ET tube using laryngoscopy or bronchoscopy, noting tracheal rings past the end of the ET tube, is the next best method of assessing correct ET tube placement.
Secondary methods for confirmation of ET intubation are an absolute requirement. Auscultate the chest and abdomen to assess for delivery of air to the lungs via either a bag-valve device or a mechanical ventilator (Figure 12-1). First, auscultate over the epigastrium to assess for the absence of sounds in the stomach. The presence of an enlarging abdomen or audible air inflation into the stomach with each positive-pressure ventilation may be the initial sign of an ET tube in the esophagus or an esophageal intubation. The next auscultation points are located at the chest wall lateral to the nipples. Auscultate bilaterally from top to bottom for the presence and equality of breath sounds. Avoid auscultating over the central portion of the chest. This may lead ...