Obese Patients, One Lung Ventilation
Conditions
Brief summary
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.
Interventions
PROCEDUREI:E ratio 1:2
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.
PROCEDUREI:E ratio 1:1
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.
Sponsors
Yonsei University
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
OTHER
Masking
TRIPLE (Subject, Caregiver, Investigator)
Eligibility
Sex/Gender
ALL
Age
40 Years to 80 Years
Healthy volunteers
No
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%
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Changes of the intrapulmonary shunt fraction and respiratory dynamic parameter | T1 (10min before one lung ventibation) T2 (30min after one lung ventilation started)T3 (60min after one lung ventilation started) T4 (10min after two lung ventilation) | shunt fraction Qs/Qt = (CcO2- CaO2)/(CcO2- CvO2), CcO2 = Hgb x 1.34 x ScO2 + PcO2 x 0.003, lung compliance : Compliance= Vt / Pplat, physiologic dead space : Vd/Vt = 1.14 x (PaCO2 - PETCO2)/PaCO2- 0.005 |
Countries
South Korea
Outcome results
None listed