Effects of 1:1 Inspiratory to Expiratory Ratios on Oxygenation and Intrapulmonary Shunt Fraction During One Lung Ventilation in the Obese Patients

Yonsei University

Status: Completed

Conditions: Obese Patients, One Lung Ventilation

Treatments: Procedure: I:E ratio 1:2; Procedure: I:E ratio 1:1

Study type: Interventional

Funder types: Other

Identifiers

NCT02185378

4-2014-0302

Details and patient eligibility

About

One-lung ventilation, even in patients with healthy weight, causes an impairment in gas-exchange and respiratory mechanics. We hypothesized that oxygenation during the one-lung ventilation in obese patients would be improved by applying inverse-ratio ventilation, reducing atelectasis in the dependent lung and resulting in reduced shunt. Because of the restrictive ventilatory effects of obesity, these patients often show a decreased functional residual capacity and decreased expiratory reserve volume, leading to an overall decreased tidal volume. These reduction leads to arterial hypoxemia, V-Q mismatch and Rt to Lt shunting. There are few studies on the one lung ventilation in obese patients about this prolonged inspiratory time ventilatory method. We plan to investigate the effect of this ventilation method in obese patients during one lung ventilation.

Enrollment: 36 patients

Sex: All

Ages: 40 to 80 years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. Above 40 years of age.
2. American Society of Anesthesiologists (ASA) Physical Status I, II, III.
3. Obesity (BMI >25 kg/ m2 )
4. thoracic surgical procedure

Exclusion criteria

1. severe functional liver or kidney disease
2. diagnosed HF ( NYHA class >3)
3. reduced pulmonary diffusion capacity < 80%

Trial design

Primary purpose: Other

Allocation: Non-Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

---

36 participants in 2 patient groups

I:E ratio 1:2

Active Comparator group

Description:

We plan to evaluate the improvement on respiratory function with different ventilation I:E ratios (1:2 vs. 1:1) during the one-lung ventilation in an obese patients.

Treatment:

Procedure: I:E ratio 1:2

I:E ratio 1:1

Active Comparator group

Description:

The purpose of our study is to compare the effects of minimal prolonged 1:1 IE ratioventilation on respiratory mechanics and oxygenation with conventional 1:2 IE ratio ventilation during OLV in obese patients.

Treatment:

Procedure: I:E ratio 1:1