[Comparison of eight deep breaths and tidal volume breathing preoxygenation techniques in morbid obese patients].
OBJECTIVE
To compare two techniques of preoxygenation, eight deep breaths (8DB) and tidal volume breathing in obese patients by measuring end-tidal fractional oxygen concentration (FETO2) and apnea time from 100% of hemoglobin saturation to 95% (T95%).


METHODS
Prospective randomized study.


METHODS
Twenty obese patients (BMI >40 kg/m2) without cardiorespiratory disease nor difficult intubation criteria were randomized into two groups of ten. One group received preoxygenation with eight deep breaths in one minute (8DB) and the other with three minutes tidal volume preoxygenation (3TV) both under FIO2 100%. FETO2 every minute of preoxygenation and T95% were measured. Data were analyzed with Mann and Whitney test. A p <0.05 was considered significant.


RESULTS
There was no significant difference between the groups regarding FETO2 values [84 +/- 4% (8DB) and 88 +/- 5% (3TV)] and T95% [176 +/- 23 s (8DB) and 181 +/- 35 s (3TV)]. The PETCO2 was significantly inferior in the 8DB group at the end of preoxygenation [PETCO2 =29 +/- 1 mmHg (8DB) and PETCO2 =36 +/- 5 mmHg (3TV)].


CONCLUSIONS
8DB and 3TV preoxygenation techniques in morbid obese patients induce similar FETO2 and T95%. However hyperventilation effects in the 8DB group are unknown.
Rapaport
S
S
Département d'anesthésie et de réanimation-II, CHU de Bordeaux, maison du Haut-Lévêque, avenue de Magellan, 33600 Pessac, France. stephane.rapaport@chu-bordeaux.fr
Joannes-Boyau
O
O
Bazin
R
R
Janvier
G
G
D000328:Adult; D000769:Anesthesia, Inhalation; D001049:Apnea / Q000378:metabolism; D015992:Body Mass Index; D005260:Female; D006400:Hematocrit; D006454:Hemoglobins / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000150:complications*; D010100:Oxygen / Q000008:administration & dosage* / Q000097:blood; D011446:Prospective Studies; D015656:Respiratory Mechanics / Q000502:physiology*; D013990:Tidal Volume / Q000502:physiology*
D006454:Hemoglobins; D010100:Oxygen