Morbid Obesity
Conditions
Brief summary
The study investigates if applying a special ventilatory strategy during anesthesia for laparoscopic gastric by pass, produces less atelectasis and better oxygenation in spite of using 100 % oxygen during pre oxygenation and induction of anesthesia. The study investigates oxygenation with blood gas samples but also with a new method that might give more information without the use of blood gas samples. Primary: Oxygenation in patients with morbid obesity improves if preoxygenation, induction and maintenance of anesthesia is performed with either a continuous positive airway pressure (CPAP) or a positive end expiratory pressure (PEEP), respectively, of 10 cm H2O, in comparison to a technique without CPAP but with a PEEP of 10 cm H2O. Secondary: The improved oxygenation during anesthesia can be prolonged inte the postoperative period if emergence from anesthesia is performed without high levels of oxygen.
Interventions
PROCEDURECPAP and 100% oxygen
During pre oxygenation and induction of anesthesia 100 % oxygen is used with a continuous positive airway pressure of 10 cmH2O, during maintenance of anesthesia a positive endexpiratory pressure of 10 cm H20 is used with controlled volume ventilation aiming at an end tidal carbon dioxide (CO2) level of 5 %. During emergence from anesthesia 100 % oxygen is used.
PROCEDURECPAP and 31% oxygen
During pre oxygenation and induction of anesthesia 100 % oxygen is used with a continuous positive airway pressure of 10 cm H2O, during maintenance of anesthesia a positive endexpiratory pressure of 10 cm H20 is used with controlled volume ventilation aiming at an end tidal CO2 level of 5 %. During emergence from anesthesia 31 % inspiratory oxygen or the inspiratory oxygen level needed to achieve a SpO2 of at least 96 % (if 31 % oxygen is not enough), is used.
PROCEDURENo CPAP and 100% oxygen
This intervention follows a standard protocol without the use CPAP during induction of anesthesia.
Sponsors
Region Västmanland
Study design
Allocation
RANDOMIZED
Intervention model
FACTORIAL
Primary purpose
TREATMENT
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Age
18 Years to 50 Years
Healthy volunteers
No
Inclusion criteria
* Adult patients scheduled for elective surgery of Morbid Obesity. * ASA 1-2. (ASA = American Society of Anesthesiologists classification). * Body mass index (BMI) ≥ 35 but \< 50
Exclusion criteria
* ASA 3 * Anticipated difficult intubation. * Major bleeding. * Problems with ventilation necessitating protocol aberrations. * Obstructive sleep apnea syndrome with CPAP treatment at home. * Angina Pectoris
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in peripheral O2 saturation(SpO2)during and 1 hour after anesthesia in comparison to awake before anesthesia. | Change in SpO2 from 5 min before start of anesthesia, to 5 min after intubation, 5 min before extubation and 1 hour after extubation. | During anesthesia SpO2 is measured at three different levels of oxygen; 21, 26 and 31 % respectively as long as SpO2 does not go lower than 87 % and compared to SpO2 immediately before anesthesia. SpO2 breathing air one hour after anesthesia is compared to SpO2 before anesthesia. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Arterial blood gas values for saturation (SaO2) | 5 min before anesthesia, 5 min after intubation, 5 min before extubation and 1 hour after anesthesia. | During anesthesia SaO2 is measured at three different levels of oxygen; 21, 26 and 31 % respectively as long as SpO2 (sic! does not go lower than 87 % and compared to SaO2 immediately before anesthesia. SaO2 breathing air one hour after anesthesia is compared to SaO2 before anesthesia. |
| Arterial oxygen tension (PaO2) | 5 min before start of anesthesia, 5 min after intubation, 5 min before extubation and 1 hour after extubation. | During anesthesia PaO2 is measured at three different levels of oxygen; 21, 26 and 31 % respectively as long as SpO2 (sic) does not go lower than 87 % and compared to PaO2 immediately before anesthesia. PaO2 breathing air one hour after anesthesia is compared to PaO2 before anesthesia. |
Countries
Sweden
Outcome results
None listed