The Effect of Decreasing the Inspired Oxygen Concentration on Post-Operative Oxygenation After Primary Lobectomy

2015-07-28 13:53:23 | BioPortfolio


The purpose of this study is to test the hypothesis that decreasing the inspired oxygen concentration during thoracic surgery requiring one lung ventilation will improve post-operative oxygenation.


Lung cancer is the leading cause of cancer mortality in the world with a very low survival rate of 15% at 5 years and approximately 1.6 million people die of lung cancer every year (1). Surgical resection of early stage non-small lung cancer offers the best chance for survival, but morbidity and mortality from the disease remains high (2). In patients with stage I non-small cell lung cancer, 5 year survival rates range from 40-95% after surgical treatment (3). Operative, in-hospital and 30-day mortality are between 1.8% and 2.5% following surgical management of primary lung tumors. Postoperative pulmonary complications such as acute lung injury, acute respiratory distress syndrome, atelectasis requiring bronchoscopy and pneumonia are relatively common after lung resection surgery (2).

Thoracic surgical patients are at increased risk of acute lung injury (ALI) (2, 4). The etiology of ALI during thoracic surgery is multifactorial and may be related to the stress of one lung ventilation (OLV) required to facilitate the surgery. The proposed mechanisms of one-lung ventilation induced lung injury include mechanical stress due over distension, damaged from atelectasis and re-expansion, ischemia, reperfusion injury, inflammation, and oxidative damage (5) all leading to ALI. The consequences of ALI account for the majority of the perioperative mortality associated with lung resection surgery (5).

Atelectasis significantly contributes to a decline in lung function post-operatively due to three primary mechanisms: compression of lung tissue during surgery, impaired surfactant function, and absorption of alveolar air (6). The rate of absorption of alveolar air is increased by increasing FiO2 and the resulting atelectasis induces inflammation and damages the structural integrity of the alveoli (7). In a study of post-operative patients atelectasis was found to account for significant intra-pulmonary shunt and persist for up to one week following cardiac surgery (8). Thus, limiting the inspired oxygen concentration may decrease atelectasis and improve post-operative lung function following lobectomy.

Hyperoxia contributes to ALI and may be detrimental if the inspired concentration of oxygen is high enough and the exposure is long enough. In the majority of experimental animal models studied, an inspired oxygen concentration greater than 90% for several days induces death (9). In humans, oxygen toxicity develops after exposure to oxygen concentration of 75% or greater after 24 hours whereas no toxicity is observed at concentration of 55% or less (9). Oxygen toxicity manifests as inflammation, endothelial dysfunction, and apoptosis and necrosis with subsequent compromise of gas exchange and systemic physiological failure in extreme toxicity (9). Changes in respiratory function are evident even with limited exposure to hyperoxia. Administration of approximately 100% oxygen prior to emergence from general anesthesia resulted in reduced pulmonary function as measured by blood oxygenation one hour after treatment compared to administration of 30% oxygen (10). Similarly a clinical trial comparing administration of 50% versus 100% oxygen after cardiopulmonary bypass demonstrated reduced blood oxygenation in the 100% oxygen group postoperatively (11).

Standard respiratory support during lobectomy for primary lung cancer involves the patient breathing greater than 95% oxygen for several hours throughout the procedure to maintain oxygenation. Protective lung ventilation strategies with lower tidal volumes (4-6 ml/kg) and PEEP have been shown to reduce lung injury and inflammation (12); however, limited clinical data is available regarding protective lung oxygenation strategies aiming to limit exposure to toxic levels of oxygen.

This study will test the hypothesis that patients ventilated with a mixture of air and oxygen (with a resulting FiO2 of 60%) throughout primary lobectomy will have lower markers of acute lung injury as measured by serum markers and better oxygenation post-operatively as compared to patients exposed to 100% oxygen. Completing this study will provide useful scientific data that will help define the influence of inspired oxygen concentration during lobectomy on lung function after thoracic surgery.


1. Al-Shahrabani F, Vallbohmer D, Angenendt S, and Knoefel WT. Surgical strategies in the therapy of non-small cell lung cancer. World journal of clinical oncology. 2014;5(4):595-603.

2. Boffa DJ, Allen MS, Grab JD, Gaissert HA, Harpole DH, and Wright CD. Data from The Society of Thoracic Surgeons General Thoracic Surgery database: the surgical management of primary lung tumors. The Journal of thoracic and cardiovascular surgery. 2008;135(2):247-54.

3. Patel AN, Santos RS, De Hoyos A, Luketich JD, and Landreneau RJ. Clinical trials of peripheral stage I (T1N0M0) non-small cell lung cancer. Seminars in thoracic and cardiovascular surgery. 2003;15(4):421-30.

4. Della Rocca G, and Coccia C. Acute lung injury in thoracic surgery. Current opinion in anaesthesiology. 2013;26(1):40-6.

5. Licker M, Fauconnet P, Villiger Y, and Tschopp JM. Acute lung injury and outcomes after thoracic surgery. Current opinion in anaesthesiology. 2009;22(1):61-7.

6. Duggan M, and Kavanagh BP. Pulmonary atelectasis: a pathogenic perioperative entity. Anesthesiology. 2005;102(4):838-54.

7. Retamal J, Bergamini B, Carvalho AR, Bozza FA, Borzone G, Borges J, Larsson A, Hedenstierna G, Bugedo G, and Bruhn A. Non-lobar atelectasis generates inflammation and structural alveolar injury in the surrounding healthy tissue during mechanical ventilation. Critical care. 2014;18(5):505.

8. Tenling A, Hachenberg T, Tyden H, Wegenius G, and Hedenstierna G. Atelectasis and gas exchange after cardiac surgery. Anesthesiology. 1998;89(2):371-8.

9. Kallet RH, and Matthay MA. Hyperoxic acute lung injury. Respiratory care. 2013;58(1):123-41.

10. Kleinsasser AT, Pircher I, Truebsbach S, Knotzer H, Loeckinger A, and Treml B. Pulmonary function after emergence on 100% oxygen in patients with chronic obstructive pulmonary disease: a randomized, controlled trial. Anesthesiology. 2014;120(5):1146-51.

11. Sinha PK, Neema PK, Unnikrishnan KP, Varma PK, Jaykumar K, and Rathod RC. Effect of lung ventilation with 50% oxygen in air or nitrous oxide versus 100% oxygen on oxygenation index after cardiopulmonary bypass. Journal of cardiothoracic and vascular anesthesia. 2006;20(2):136-42.

12. Ventilation with lower tidal volumes as compared with traditional tidal volumes for acute lung injury and the acute respiratory distress syndrome. The Acute Respiratory Distress Syndrome Network. The New England journal of medicine. 2000;342(18):1301-8.

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Outcomes Assessor), Primary Purpose: Prevention




60% oxygen, 100% oxygen


Yale New Haven Hospital
New Haven
United States


Not yet recruiting


Yale University

Results (where available)

View Results


Published on BioPortfolio: 2015-07-28T13:53:23-0400

Clinical Trials [1823 Associated Clinical Trials listed on BioPortfolio]

Computer-assisted Oxygen Therapy Weaning in Critically Ill Children

The study is designed to evaluate the feasibility, safety and clinical utility of using an adaptive model to wean oxygen by computer assistance. Investigators hypothesize that weaning oxyg...

Oxygen Reserve Index to Reduce Hyperoxia

Excessive oxygen administration is known to cause oxidative stress, and absorption atelectasis. Hyperoxia is very common in general anesthesia settings. Even though there are concerns in u...

Oxygen Reserve Index (ORI) Validation in Healthy Volunteers

Masimo Corporation has developed a new parameter for noninvasive monitoring by optical sensors, Oxygen Reserve index (ORI). ORI is believed to correlate with the partial pressure of arteri...

Oxygenation Targets in Cardiac Surgery Patients - a Before-and-after Study

During surgery high concentrations of supplementary oxygen are routinely administrated. However, there is increasing evidence of potential harm with liberal oxygen therapy. The hypothesis ...

ORI2 : ORI for hyperOxia Reduction in ICU

The ORI (Reserve Oxygen Index) is an index measured through sensors SpO2 (oxygen saturation by pulse oximetry - Radical-7 MASIMO) that evaluates noninvasively PaO2 (partial pressure of oxy...

PubMed Articles [4158 Associated PubMed Articles listed on BioPortfolio]

Pulmonary mechanics and structural lung development after neonatal hyperoxia in mice.

Supplemental oxygen exposure administered to premature infants is associated with chronic lung disease and abnormal pulmonary function. This study used mild (40%), moderate (60%), and severe (80%) oxy...

Hyperoxia and oxidative stress in anesthesia and critical care medicine.

Oxygen administration is particularly relevant in patients undergoing surgery under general anesthesia and in those who suffer from acute or critical illness. Nevertheless, excess O2, or hyperoxia, is...

Hyperbaric oxygen therapy in acute stroke: is it time for Justitia to open her eyes?

Hypoxia is a critical component of neuronal death in patients with stroke. Therefore increasing oxygenation of brain tissue seems to be a logical therapy against cerebral ischemia. Oxygen therapy exis...

The effect of systemic hyperoxia and hypoxia on scotopic thresholds in people with early and intermediate age-related macular degeneration.

PurposeMorphological retinal changes combined with functional evidence implicate hypoxia in the pathogenesis of age-related macular degeneration (AMD). However, the role of hypoxia in the scotopic thr...

Oxygen reserve index, a new method of monitoring oxygenation status: what do we need to know?

The oxygen reserve index (ORI) is a new technology that provides real-time, non-invasive, and continuous monitoring of patients' oxygenation status. This review aimed to discuss its clinical utility, ...

Medical and Biotech [MESH] Definitions

An abnormal increase in the amount of oxygen in the tissues and organs.

The rate at which oxygen is used by a tissue; microliters of oxygen STPD used per milligram of tissue per hour; the rate at which oxygen enters the blood from alveolar gas, equal in the steady state to the consumption of oxygen by tissue metabolism throughout the body. (Stedman, 25th ed, p346)

Stable oxygen atoms that have the same atomic number as the element oxygen, but differ in atomic weight. O-17 and 18 are stable oxygen isotopes.

Molecules or ions formed by the incomplete one-electron reduction of oxygen. These reactive oxygen intermediates include SINGLET OXYGEN; SUPEROXIDES; PEROXIDES; HYDROXYL RADICAL; and HYPOCHLOROUS ACID. They contribute to the microbicidal activity of PHAGOCYTES, regulation of signal transduction and gene expression, and the oxidative damage to NUCLEIC ACIDS; PROTEINS; and LIPIDS.

Unstable isotopes of oxygen that decay or disintegrate emitting radiation. O atoms with atomic weights 13, 14, 15, 19, and 20 are radioactive oxygen isotopes.

More From BioPortfolio on "The Effect of Decreasing the Inspired Oxygen Concentration on Post-Operative Oxygenation After Primary Lobectomy"

Quick Search

Relevant Topics

Surgical treatments
Surgery is a technology consisting of a physical intervention on tissues. All forms of surgery are considered invasive procedures; so-called "noninvasive surgery" usually refers to an excision that does not penetrate the structure being exci...

Pulmonary relating to or associated with the lungs eg Asthma, chronic bronchitis, emphysema, COPD, Cystic Fibrosis, Influenza,  Lung Cancer, Pneumonia, Pulmonary Arterial Hypertension, Sleep Disorders etc Follow and track Lung Cancer News ...

Lung Cancer
Lung cancer is the uncontrolled cell growth in tissues of the lung. Originating in the lungs, this growth may invade adjacent tissues and infiltrate beyond the lungs. Lung cancer, the most common cause of cancer-related death in men and women, is respons...

Searches Linking to this Trial