Confirming placement of endotracheal tube: Monitoring techniques

Ahmed Raza

Reviewed by Jessica Munoz DPN, RN, CEN, providing nurse training at Yale New Haven Health-Bridgeport Hospital since 2022. Previously in healthcare and education at Griffin Hospital, St. Vincent's College of Nursing and Sacred Heart University Medical Center.

Endotracheal intubation

Endotracheal intubation is a medical procedure in which a tube is inserted into the trachea through the nose or mouth, most commonly via the oral route. This procedure is performed to secure the airway for mechanical ventilation, facilitate the administration of medications, and prevent airway obstruction. It is commonly used for patients who are unable to breathe independently due to unconsciousness, respiratory failure, or the need for anesthesia during surgery (Goto el al., 2019).

Endotracheal intubation can cause significant discomfort since it is an invasive procedure. To mitigate this, patients are typically given sedatives, muscle relaxants, or general anesthesia to minimize pain and distress (Tarwade & Smischney (2022).

Esophageal detector device (EDD)

The esophageal detector device (EDD) is a diagnostic tool used to confirm endotracheal intubation by assessing negative pressure changes in the airway. It is beneficial when end-tidal carbon dioxide (ETCO₂) monitoring may be unreliable. However, EDD may produce false-negative results in infants, parturients, and morbidly obese patients (Sakles et al, 2023). While EDD is useful, waveform capnography remains the preferred standard for confirming tracheal placement, especially in emergencies.

Waveform capnography

Waveform capnography is the gold standard for verifying endotracheal tube (ETT) placement. It continuously measures the concentration of CO₂ in exhaled air and provides real-time feedback about ventilation effectiveness. Capnography is particularly beneficial in cardiac arrest, respiratory distress, and shock, as it gives insight into the severity of the condition and response to treatment.

The American Heart Association (AHA) recommends continuous waveform capnography, in addition to clinical assessment, as the most reliable method for verifying and monitoring ETT placement (AHA, 2020).

Upper airway ultrasonography (USG)

Upper airway ultrasonography (USG) is a non-invasive, portable, and rapid method for confirming ETT placement, particularly in cases where capnography may be unreliable due to low pulmonary blood flow. USG provides real-time visualization of the airway structures and can effectively distinguish between esophageal and tracheal intubation.

USG allows for rapid tracheal versus esophageal intubation identification and serves as a valuable adjunct to capnography, particularly in emergency and critical care settings (Fazlin et al., 2024).

Primary verification methods, such as direct visualization during intubation, can be complemented by secondary confirmation techniques, including USG.

Conclusion

Confirming the correct placement of an endotracheal tube is essential for ensuring adequate ventilation and patient safety. Among the available methods, waveform capnography remains the gold standard due to its high sensitivity and specificity in detecting proper tube placement. However, in scenarios where capnography may be less reliable, such as low pulmonary blood flow states, adjunct techniques like upper airway ultrasonography (USG) provide a valuable alternative. USG offers rapid, non-invasive, and real-time confirmation of ETT positioning, complementing traditional methods. Additionally, while esophageal detector devices (EDD) can be helpful, they have limitations in specific patient populations. By integrating multiple verification techniques, healthcare providers can enhance the accuracy of ETT placement confirmation, reducing the risk of complications and improving patient outcomes.

Citation

• AHA. (2020). 2020 American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation, 142(Suppl 2), S366–S468.
• Sakles, J. C., Ross, C., & Kovacs, G. (2023). Preventing unrecognized esophageal intubation in the emergency department. Journal of the American College of Emergency Physicians open, 4(3), e12951. https://doi.org/10.1002/emp2.12951
• Tarwade, P., & Smischney, N. J. (2022). Endotracheal intubation sedation in the intensive care unit. World journal of critical care medicine, 11(1), 33–39. https://doi.org/10.5492/wjccm.v11.i1.33
• Goto, T., Goto, Y., Hagiwara, Y., Okamoto, H., Watase, H., & Hasegawa, K. (2019). Advancing emergency airway management practice and research. Acute medicine & surgery, 6(4), 336–351. https://doi.org/10.1002/ams2.428
• Fazlin, Jazman, Aireene, Fari, & Zara (2024). The role of upper airway ultrasonography in tracheal necrosis diagnosis: a case report. The ultrasound journal, 16(1), 35. https://doi.org/10.1186/s13089-024-00385-2