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October 15, 2012
8:00:00 AM - 11:00:00 AM
Room Hall C-Area F
TSE Mask Improves Oxygenation and Prevents Severe Desaturation in Elderly Patients Under Deep Propofol Sedation During Colonoscopy
Sylviana Barsoum, M.D., Shaul Cohen, M.D., Kristen Dauphinee, M.D., Christian McDonough, M.D., Shruti Shah, M.D., Mordechai Bermann, M.D., Candy Anim, M.D., Laurie Spina, M.D., Adil Mohiuddin, M.D., James Tse, M.D.,Ph.D.
UMDNJ-RWJMS, New Brunswick, New Jersey, United States
Introduction: Patients undergoing colonoscopy routinely receive nasal cannula (NC) O2 and IV sedation. Over-sedation and/or airway obstruction may cause respiratory depression and severe desaturation (Desat), especially in elderly patients with multiple diseases. A simple plastic sheet has been shown to improve oxygenation by transforming a NC to a face tent (TSE “Mask”) in deeply sedated patients during upper GI endoscopy in a prospective study.1 This technique has been used in the Endoscopy Suite. We examined its effectiveness in improving oxygenation and preventing severe Desat in elderly patients during colonoscopy.

Methods: Review of elderly patients (≥65 y/o) who underwent colonoscopy identified 2 groups. Group 1 (NC, n=20) received only NC O2. Group 2 (TM, n=74) received NC O2 and a TSE “Mask” using a clean clear plastic sheet to cover patient's eyes, nose and mouth (Photo).1-3 Patients received NC O2 (3-5 l/min or higher as needed) and only IV propofol for sedation. Student t-test and Chi Square test were used for analysis. A p value <0.05 was considered as significant. (Mean±S.D.)

Results: There were no differences in age (NC: 74±9 yrs; TM: 74±7), BMI (NC: 27±4 kg/m2; TM: 28±6), room air (RA) O2 Sat (NC: 98±2%; TM: 98±2%), EtCO2 (NC: 30±10 mm Hg; TM: 33±7), over-all propofol dosage (NC: 211±78 mcg/kg/min; TM:177±60), duration (NC: 25±15 min; TM: 25±12), the highest NC O2 flow (NC: 5.3±1.9 l/min; TM: 4.7±1.1) and bag-mask ventilation (NC: 2/20; TM: 1/74).

There were significant differences in ASA Physical Status (NC: 4 ASA III/20; TM: 36 ASA III-IV/74, p<0.02), O2 Sat after 5 min pre-oxygenation (NC: 99±2%; TM:100±1%, p<0.02), FiO2 (NC: 0.34±0.10; TM: 0.76±0.15, p<0.0001), FeO2 (NC: 0.50±0.14; TM: 0.82±0.12, p<0.05), inhaled CO2 (NC: 3±3 mm Hg; TM: 7±5, p<0.05), the lowest O2 Sat (NC: 93±9%; TM: 97±5%, p<0.005) (Fig. 1) and severe Desat (O2 Sat≤85%) (NC: 4/20; TM: 1/74, p<0.001) (Fig. 2).

In 3 NC patients, NC was converted to TSE "Mask" due to severe Desat (O2 Sat: 80±15%). Their O2 Sat was increased to 98±2% and 97±1% at 5 min intervals. Their FiO2 was increased from 0.30 (NC) to 0.80 (TM).

Conclusion: These data show that pre-oxygenation with a TSE “Mask” improves oxygenation and prevents severe desaturation in elderly patients under deep propofol sedation during colonoscopy. It improves oxygenation by increasing O2 concentration without raising NC O2 flow. TM group has less severe desaturation than NC group even though the TM group has more patients with severe diseases (ASA III-IV). This simple face tent can also be used as a rescue device when patient’s oxygenation deteriorates. It takes only a few seconds to prepare at no cost and may improve patient safety. It may reduce procedure interruptions and should be routinely used prior to sedation during colonoscopy.

Ref: 1. Anesth 107:A922, 2007; 2. Anesth 102:484, 2005; 3.

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