TITLE: EVALUATION OF A NEW AND FASTER METHOD TO EXCHANGE AN ENDOTRACHEAL TUBE

AUTHORS: Jean-Louis Horn, MD
AFFILIATION: OHSU, Portland, OR.

INTRODUCTION: Endotracheal (ET) tube exchange may represent a challenge for anesthesiologists. They routinely use tube exchangers in sedated patients as a guide to replace an ET tube. In some instance, a prolonged manipulation of the airway without ventilation in critically ill patients with severe respiratory dysfunction (i.e. patient with ARDS) may precipitated an adverse outcome. In this study we evaluate the usefulness of a new and faster method to exchange an ET tube with a Cook Airway Exchanger Catheter (CAEC).
METHODS: Institutional approval for this study was obtained. After informed consent, 7 ASA I or II patients scheduled for elective surgery under general endotracheal anesthesia were consented to participate in the study. Patients were anesthetized, paralyzed and intubated under direct laryngoscopy. Then, they were randomly assigned to 2 groups. Group 1 had the ET tube exchanged with a CAEC inserted inside the ET tube per manufacturer instructions. A blinded observer recorded SaO₂, HR, blood pressure and the apnea interval using the capnographe curve. Once the ET tube was secured, it was exchanged a second time by placing the CAEC adjacent to the ET tube under direct laryngoscopy. Proper CAEC position was confirmed by capnography. The new ET tube was threaded over the CAEC, the old ET tube was then removed while the new tube was inserted in the trachea. Hemodynamic values and timing were recorded again with the same blind observer. Group 2 had the same procedure done except that their ET tube was exchanged first with the new method and then with the recommended manufac- turer method. Data were analyzed by ANOVA.
RESULTS: No statistical differences were observed in hemo- dynamic data, SaO₂ or difficulties for the procedure. Duration of apnea was significantly different (P<0.005) between the 2 methods. The classic method required 35.4±8.8 seconds to exchange the ET tube versus 8.1±2.6 seconds for the new method.
CONCLUSIONS: The new method described here to exchange an ET tube is much faster than the classic method and therefore represents a valid alternative for patients with severe respiratory dysfunction. So also, it appears safer and less traumatic to the tracheal wall since movements of the CAEC during tube exchanges are minimized. The use of laryngoscopy may represent an additional stress¹ for the patient, but it can be easily controlled with adequate sedation.
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¹Uchida T. Can. J. Anaesth. 1995 44(6): 674-676.