Comparison of Oxygen Saturation During Different Intraoperative Positions

One-Lung Ventilation Clinical Trial

Official title:

A Comparison of Oxygen Saturation Between Lateral Decubitus Lung Surgery and Port Access Procedures in Dorsal Decubitus

Clinical Trial Details — Status: Terminated

Administrative data

• NCT number: NCT01744886
• Other study ID #: B126201215656
• Status: Terminated
• Phase: N/A
• First received: December 6, 2012
• Last updated: October 16, 2014
• Start date: December 2012
• Est. completion date: September 2013

Study information

• Verified date: October 2014
• Source: Onze Lieve Vrouw Hospital
• Contact: n/a
• Is FDA regulated: No
• Health authority: Belgium: Ethics Committee
• Study type: Interventional

Clinical Trial Summary

One-lung ventilation (OLV) during thoracic surgery and its effect on oxygen saturation has been discussed in multiple studies. Literature shows different ventilation strategies and possible hypoxemia has been attributed to several issues.

Port-access cardiac surgical procedures ("key hole surgery" including mitral valve repair or prosthesis, tricuspid valve repair or prosthesis, atrial septal defect closure or a combination of these) require the use of OLV as well. Its effect on oxygen saturation has not been studied previously.

The aim of this study is to investigate the effect of extracorporeal circulation (ECC) and patient positioning on oxygen saturation and on the progress of hypoxemia throughout OLV during port-access in comparison to oxygen saturation throughout OLV during lateral decubitus thoracotomies.

Description:

OLV is a technique that allows isolation of the individual lung under anesthesia. It is required for a number of thoracic surgical procedures as well as port-access procedures.

The use of a double lumen tube allows easy switching from two-lung to single lung ventilation.

For many thoracic operations the patient will be in the lateral decubitus position. The primary physiologic change that takes place on initiation of OLV is the presence of trans-pulmonary shunting, causing impaired oxygenation and occasionally hypoxemia. The degree of shunt is reduced due to the effect of gravity which increases pulmonary blood flow to the dependent lung and it will be further decreased due to a phenomenon termed hypoxic pulmonary vasoconstriction (HPV).

Hypoxemia may occur during OLV in lateral decubitus position due to the restriction of the dependent lung expansion caused by mediastinal weight therefore leading to atelectasis. Increased ventilation pressure and lung volume of the dependent lung impedes perfusion and contributes to hypoxemia.

Presentation of hypoxemia during OLV is multifactorial. It depends on the operation side (OLV better in left thoracotomies), on preoperative lung function [best indicator = Partial Pressure of Oxygen in Arterial Blood (PaO2) divided by Fraction of Inspired Oxygen (FIO2)] and on the distribution of perfusion. The PaO2/FIO2 is the best parameter to describe the full spectrum of ventilation-perfusion abnormalities, independent of the inspired oxygen concentration level.

The patients are divided into 2 groups according to the surgical procedure as follows:

Port-access group (n=25), and lateral decubitus lung surgery group (n=25). Standard monitoring will be applied intraoperatively [electrocardiography (ECG), pulse-oxymetry (SpO2), invasive and non-invasive blood pressure]. After induction of anesthesia, an appropriately sized double lumen tube will be inserted and its position will be checked using fibroscopy. All patients will be placed on a volume controlled mode of ventilation with the following settings: tidal volume between 5 and 10 ml/kg and FIO2 at 50% and 4 cm H2O of positive end-expiratory pressure (PEEP). Respiratory frequency and tidal volume will be adjusted to maintain end-tidal carbon dioxide (ETCO2) between 30 and 40 mmHg. ETCO2 levels and SpO2 will be monitored continuously.

If SpO2 declines below 90% the ventilator settings will be adapted according to the following protocol: First the FIO2 is increased to 80%. If this is insufficient FIO2 is increased to 100%. If this remains insufficient, continuous positive airway pressure (CPAP) [5 cm water (H2O) pressure] is applied to the non-ventilated lung. If this is still insufficient the surgeon will be asked to allow for temporary recruitment of the non-ventilated lung.

Recruitment information / eligibility

• Status: Terminated
• Enrollment: 29
• Est. completion date: September 2013
• Est. primary completion date: September 2013
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 18 Years to 80 Years

Eligibility

Inclusion Criteria:

• Patients undergoing lateral decubitus lung surgery or port-access.

• American Society of Anesthesiologists Physical Status (ASA) II or III.

• Age between 18-80 years.

• Patients willing to sign consent.

Exclusion Criteria:

• Pre-existing interstitial lung disease.

• Pre-existing obstructive airway disease.

• Inability or unwillingness of study participant to give written informed consent.

• Patients expected to have a difficult intubation for anatomical reasons.

Study Design

Allocation: Non-Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Open Label, Primary Purpose: Treatment

Related Conditions & MeSH terms

• One-Lung Ventilation

Intervention

Procedure:
• maintain oxygenation during one lung ventilation
All study patients will be placed on a volume controlled mode of ventilation with the following settings: tidal volume between 5 and 10 ml/kg and FIO2 at 50% and 4 cm H2O PEEP. Respiratory frequency and tidal volume will be adjusted to maintain ETCO2 between 30 and 40 mmHg. ETCO2 levels and SpO2 will be monitored continuously. If SpO2 declines below 90% the ventilator settings will be adapted according to the following protocol: First the FIO2 is increased to 80%. If this is insufficient FIO2 is increased to 100%. If this remains insufficient 5 cm H2O of CPAP is applied to the non-ventilated lung. If this is still insufficient the surgeon will be asked to allow for temporary recruitment of the non-ventilated lung.

Locations

Country	Name	City	State
Belgium	OLV Hospital	Aalst

Sponsors (1)

Lead Sponsor	Collaborator
Onze Lieve Vrouw Hospital

Country where clinical trial is conducted

Belgium, 

References & Publications (2)

Karzai W, Schwarzkopf K. Hypoxemia during one-lung ventilation: prediction, prevention, and treatment. Anesthesiology. 2009 Jun;110(6):1402-11. doi: 10.1097/ALN.0b013e31819fb15d. Review. — View Citation

Watanabe S, Noguchi E, Yamada S, Hamada N, Kano T. Sequential changes of arterial oxygen tension in the supine position during one-lung ventilation. Anesth Analg. 2000 Jan;90(1):28-34. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	oxygen saturation	To assess if more interventions are needed to maintain oxygenation during one-lung ventilation in port-access procedures compared with the non-cardiac surgical procedures under one lung ventilation in lateral decubitus	each 15 min once one-lung ventilation is initiated	Yes
Primary	oxygen saturation	To compare oxygen saturation during one-lung ventilation in patients undergoing lateral decubitus for non-cardiac thoracic surgery, requiring more than 20 minutes of one-lung ventilation using double lumen intubation, versus patients undergoing port-access cardiac surgical procedures.	20 minutes after initiation of one-lung ventilation	Yes
Secondary	oxygen saturation	To assess if oxygen saturation during one-lung ventilation depends on patient positioning.	15 minutes of one-lung ventilation after patient positioning	Yes