Oxygenation Test During General Anesthesia

Region Västmanland

Status: Completed

Conditions: Morbid Obesity

Treatments: Procedure: CPAP and 31% oxygen; Procedure: No CPAP and 100% oxygen; Procedure: CPAP and 100% oxygen

Study type: Interventional

Funder types: Other

Identifiers

NCT01559402

Dnr 2011 / 462

Details and patient eligibility

About

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.

Enrollment: 40 patients

Sex: All

Ages: 18 to 50 years old

Volunteers: No Healthy Volunteers

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

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Factorial Assignment

Masking: Single Blind

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40 participants in 3 patient groups

Start O2 100% and CPAP 10, end O2 100%.

Experimental group

Description:

This arm describes some aspects of ventilation during anesthesia for laparoscopic gastric bypass. Pre-oxygenation is with an inspiratory oxygen fraction(FIO2) of 1.0, supplied by a continuous positive airway pressure of 10 centimeters of water(cmH2O), during anesthesia a positive end-expiratory pressure of 10 cmH2O is used and during emergence from anesthesia a FIO2 of 1.0 is used. The intervention associated with this arm is labeled CPAP and 100% oxygen.

Treatment:

Procedure: CPAP and 100% oxygen

Start O2 100% and CPAP 10, end O2 31%.

Experimental group

Description:

This arm describes some aspects of ventilation during anesthesia for laparoscopic gastric bypass. Pre-oxygenation is with a FIO2 of 1.0, supplied by a continuous positive airway pressure of 10 cmH2O, during anesthesia a positive end-expiratory pressure of 10 cmH2O is used and during emergence from anesthesia a FIO2 of 0.3 is used. The intervention associated with this arm is labeled CPAP and 31% oxygen.

Treatment:

Procedure: CPAP and 31% oxygen

Start O2 100% and CPAP 0, end O2 100%.

Experimental group

Description:

This arm describes some aspects of ventilation during anesthesia for laparoscopic gastric bypass. Pre-oxygenation is with a FIO2 of 1.0, without a continuous positive airway pressure, during anesthesia a positive end-expiratory pressure of 10 cmH2O is used and during emergence from anesthesia a FIO2 of 1.0 is used. The intervention associated with this arm is labeled No CPAP and 100% oxygen.

Treatment:

Procedure: No CPAP and 100% oxygen