title: Supplementation of pre-oxygenation in morbidly obese patients using nasopharyngeal oxygen insufflation.
abstract: During apnoea following induction of anaesthesia, morbidly obese patients may suffer a rapid decrease in oxygen saturation. This study compares pre-oxygenation alone with pre-oxygenation followed by nasopharyngeal oxygen insufflation on the onset of desaturation occurring during the subsequent apnoea. A randomised controlled trial was performed in 34 morbidly obese patients undergoing gastric bypass or gastric band surgery. Seventeen patients received nasopharyngeal oxygen supplementation following pre-oxygenation (Study group, body mass index = 41.8 (6.9) kg.m(-2)), and the other 17 patients received pre-oxygenation alone (Control group, body mass index = 42.7 (5.4) kg.m(-2)). Time from the onset of apnoea until S(p)o(2) fell to 95% was compared between the two groups with a cut-off of 4 min. In the control group, the S(p)o(2) fell from 100% to 95% during the subsequent apnoea in 145 (27) s, with a significantly negative correlation (r(2) = 0.66, p < 0.05) between the time to desaturation to 95% and the body mass index. In the study group, the S(p)o(2) was maintained in 16 of 17 patients at 100% for 4 min when apnoea was terminated. In conclusion, nasopharyngeal oxygen insufflation following pre-oxygenation in morbidly obese patients delays the onset of oxyhaemoglobin desaturation during the subsequent apnoea.
authors.affiliation: Department of Anaesthesiology, American University of Beirut, Beirut, Lebanon. abaraka@aub.edu.lb
authors.forename: A S
authors.initials: AS
authors.lastname: Baraka
authors.forename: S K
authors.initials: SK
authors.lastname: Taha
authors.forename: S M
authors.initials: SM
authors.lastname: Siddik-Sayyid
authors.forename: G E
authors.initials: GE
authors.lastname: Kanazi
authors.forename: M F
authors.initials: MF
authors.lastname: El-Khatib
authors.forename: C M
authors.initials: CM
authors.lastname: Dagher
authors.forename: J-M A
authors.initials: JM
authors.lastname: Chehade
authors.forename: F W
authors.initials: FW
authors.lastname: Abdallah
authors.forename: R E
authors.initials: RE
authors.lastname: Hajj
mesh_terms: D000328:Adult; D050110:Bariatric Surgery; D001824:Body Constitution; D015992:Body Mass Index; D005260:Female; D006801:Humans; D007327:Insufflation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009305:Nasopharynx; D009767:Obesity, Morbid / Q000097:blood / Q000150:complications / Q000601:surgery*; D010100:Oxygen / Q000097:blood; D010102:Oxygen Inhalation Therapy / Q000379:methods*; D010108:Oxyhemoglobins / Q000378:metabolism; D011300:Preoperative Care / Q000379:methods*
chemical_list: D010108:Oxyhemoglobins; D010100:Oxygen