a b s t r a c t

Although advances have been made in the approach to airway management, intubating critically ill patients in the Emergency Department (ED) can still be perilous. In some cases, poor peripheral perfusion may preclude obtaining a consistent or reliable pulse oximetry waveform, and the intubator will not accurately know when the patient begins to desaturate. We describe a case of a patient requiring intubation in whom we were unable to obtain a consistent pulse oximetry waveform. We utilized a novel technique in which a Biphasic Cuirass Ven- tilation (BCV) device was applied to maintain oxygenation and ventilation during the performance of rapid se- quence intubation (RSI). This technique has the potential to improve the safety of RSI, especially in the critically ill patient.

(C) 2018

1. Introduction

Advances in in the approach to airway management, including the use of video laryngoscopy, apneic oxygenation [1], and delayed se- quence intubation [2], have helped improve the safety of emergent air- way management. Despite this, a recent study demonstrated that about a third of patients desaturate during attempted endotracheal intubation [3].

Pulse oximeters may fail to record a consistent or accurate oxygen saturation during low perfusion states [4], which creates a scenario fraught with risk in a patient who requires intubation. We present one such case in which we utilized a novel technique with a Biphasic Cuirass Ventilation (BCV) device (Hayek Medical, London, United Kingdom) to augment the safety of the intubation.

1. Case

A 53-year-old woman with chronic obstructive pulmonary disease was transported to the ED via ambulance. Upon arrival, the patient had a depressed mental status and was unable to provide any history. According to her family, the patient was feeling at baseline until she had a witnessed syncopal episode followed by decreased

* Corresponding author at: 901 Rancho Lane Ste 135, Las Vegas, NV 89106, United States of America.

E-mail address: [email protected] (T. Zitek).

responsiveness. The pre-hospital glucose was 108 mg/dL. Vital signs upon ED arrival included temperature 97.6?, heart rate 120, blood pres- sure 125/96, respiratory rate 30, and end tidal CO2 of 20 mm Hg. The patient’s hands and feet were noted to be cold to the touch, and a con- sistent pulse oximetry waveform was unable to be obtained to record an oxygen saturation. The initial Glasgow Coma Scale score was 10. An intravenous (IV) crystalloid bolus was administered. The lactate level returned at 8.8 mmol/L, and broad-spectrum antibiotics were initiated to cover for possible sepsis.

A CT brain was obtained, which revealed a small intraparenchymal hemorrhage. Upon reassessment after returning from the CT, the pa- tient was noted to have diminishing mental status with a GCS of 6. The decision was made to intubate the patient, but a consistent pulse oximeter waveform was still unable to be obtained.

The patient was preoxygenated with oxygen via a non-rebreather face mask, plus a nasal cannula with oxygen running at 15 L/min. Vari- ous maneuvers were performed in hopes of achieving a consistent pulse oximetry waveform, including application of warmed blankets and moving the pulse oximetry probe to different fingers, the ear lobes, and the nose – none of these maneuvers was successful.

Our ED has access to a BCV device, which the care team felt could have potential utility to improve the safety of this potentially dangerous intubation. The BCV device was placed over the patient’s chest wall dur- ing the pre-oxygenation period (see Fig. 1), and set to a negative pres- sure mode at -20 cm H₂O, which ensures a tight seal of the cuirass on the chest wall. The BCV was then switched to a biphasic ‘control’

https://doi.org/10.1016/j.ajem.2018.07.038

0735-6757/(C) 2018

Fig. 1. Demonstrates how the BCV device can be placed on a patient in the peri-intubation period.

mode, with an inspiratory pressure of -25 cm H₂O and an expiratory pressure of +5 cm H₂O with a respiratory rate of 20 breaths per minute. The total time to apply the BCV device and to achieve the control mode pressures was timed at 356 s.

The patient received 10 mg of etomidate and 70 mg of rocuronium, and the nasal cannula was left in place to provide supplemental oxygen at 15 L/min. Although the patient was paralyzed, she was being actively ventilated by the BCV device at 20 breaths per minute throughout the intubation procedure. The patient was successfully intubated via direct laryngoscopy on first attempt by a third-year emergency medicine res- ident. The oxygen saturation was never known during the intubation at- tempt, but the heart rate did not change, no cyanosis was observed, and the end tidal CO2 did not increase.

1. Discussion

To our knowledge, this is the first described use of a BCV device to assist with a high risk intubation in the ED. We believe this technique has the potential to increase the safety of airway management in

precarious situations, such as the case of a patient without a functioning pulse oximeter, and we are unaware of any literature providing guid- ance on intubating a patient without a reliable pulse oximetry reading. While apneic oxygenation may transiently help prevent desaturation [1], ventilating a patient with the BCV while providing 15 L of oxygen per minute via nasal cannula likely provides a superior means of avoiding desaturation during RSI. Paralysis has been demonstrated to enhance the success of laryngoscopy and delivery of the endotracheal tube [5]. Some providers may choose to avoid paralysis in a patient without a reliable pulse oximetry or with severe acidosis, but the ability to both paralyze and still ventilate a patient utilizing a BCV device with RSI may be preferable in those circumstances.

1. Conclusions

This case describes a novel means by which a BCV device may serve as a useful adjunct to RSI in high-risk situations. This airway manage- ment strategy merits additional investigation. Our institution is cur- rently performing a study to further assess the utility of the BCV during RSI in the emergency setting.

Support

This research did not receive any specific grant from funding agen- cies in the public, commercial, or not-for-profit sectors. However, a bi- phasic cuirass ventilator was supplied to University Medical Center of Southern Nevada by Hayek Medical.

Declaration of interest

None of the authors receive any financial support from the company that makes the biphasic cuirass ventilator (Hayek Medical), but the company supplied our department with a free ventilator after we expressed interest in doing research with the device on patients in the peri-intubation period. Hayek Medical had no role in the development of this case report. We have no other conflicts of interest to report.

Prior presentations

None.

References

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