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A922
October 14, 2007
2:00 PM - 4:00 PM
Room Hall D, Area O,
TSE "Mask" Improves Oxygenation in Deeply Sedated Patients with Nasal Cannula during Upper Endoscopy
Shaul Cohen, M.D., Tamir Ben-Menachem, M.D., Adhev Kuppusamy, M.D., Shruti Shah, M.D., James Tse, M.D., Ph.D.
Anesthesia, UMDNJ-Robert Wood Johnson Medical School, New Brunswick, New Jersey
Introduction: Oxygen desaturation is a common occurrence in patients receiving moderate-to-deep sedation during upper endoscopy. During these procedures, patients typically receive supplemental O2 via a nasal cannula. A nasal cannula often becomes an ineffective tool in providing O2 when the patient's mouth is kept open with a bite block and an endoscopic probe is in the oropharynx. It has been reported that a new type of face tent (TSE "Mask") can easily convert an ineffective nasal cannula into an effective device that increases FiO2 to 40-60% and improves oxygenation in patients during upper endoscopy1-2. However, a controlled, randomized clinical study has not been performed. We tested this hypothesis in patients undergoing esophagogastroduodenoscopy, endoscopic ultrasound and endoscopic retrograde cholangiopancreatogaphy.

Methods: Our IRB approved this study. Patients (ASA physical status class I or II) were consented and assigned randomly to the control (Con) or TSE "Mask" group (T) using an Excel-Random-Generator. The same anesthesiologist provided the standard anaesthesia care to all patients in this study. Routine monitors included ECG, BP cuff, pulse oximetry and capnography. Patients received O2 via nasal cannula (4 to 10 liter/min as needed) in the absence (Con, N=50) or presence (T, N=50) of a TSE "Mask". This new type of face tent is simply a plastic sheet (12" x 20") made out of a clean, clear specimen bag and is used to cover the face of the patient to create an O2 reservoir as previously described1,2. Patients then received intravenous propofol that was titrated to achieve deep sedation as required by the endoscopic procedure. Data collected for comparison included the highest O2 flow, the lowest O2 saturation, the need for assisted ventilation and oxygenation using an Ambu bag, the length of the procedure and the total amount of propofol administrated. Data are presented as Mean± S.E. SPSS is used for statistical analysis. A p value < 0.05 is considered as statistically significant.

Results: There is no significant difference between two groups in the duration of the procedure (Con: 37± 3 min vs. T: 32± 3 min) and the total amount of propofol administrated (Con: 563± 49 mg vs. T: 510± 51 mg). There is a significant difference in the highest O2 flow (Con: 8.2 ± 0.4 l/min vs.T: 6.8± 0.4 l/min), the lowest O2 saturation (Con: 86.6± 1.8 % vs. T: 93.4± 0.9 %) and the need for assisted ventilation and oxygenation using an Ambu bag (Con: 24% vs.T 2%; or Con: 12 vs. T: 1) (Figure 1).

Conclusions: These data suggest that this new type of face tent converts an ineffective nasal cannula to an effective device in O2 delivery during upper endoscopy. It improves oxygenation in patients receiving deep sedation. It also reduces the need for assisted ventilation and oxygenation in these patients. TSE "Mask" utilizes a plastic bag that is ubiquitous at no additional cost. It should be used routinely during upper endoscopic procedures.

References: 1. Anesthesiology 102: 484, 2005, 2. Sci & Edu Exh #44, 2006 ASA Annual Meeting.[figure1]

Anesthesiology 2007; 107: A922
Figure 1