Clinical trial NCT01495936: The Effect of Two Airway Interventions, During One Lung Ventilation, on Blood Oxygen Content
Official title: The Influence Of Continuous Positive Airway Pressure and Positive End-Expiratory Pressure, With A Recruitment Maneuver, On Oxygenation During One Lung Ventilation Employing A Lung Protective Ventilation Strategy.
Study type: INTERVENTIONAL
Overall status: UNKNOWN
Phase: NA
Conditions: Thoracic, Diseases
Keywords: One Lung Ventilation (OLV)
Continuous Positive Airway Pressure (CPAP)
Positive End Expiratory Pressure (PEEP)
Lung recruitment maneuver
Hypoxia
Lead sponsor: London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's
Sponsor class: OTHER
First posted: 2011-12-20
Enrollment: 40
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: Patients requiring one lung ventilation (OLV) for open thoracic surgery will be ventilated (breathing performed by a breathing machine) during anesthesia using a lung protective ventilation strategy (small breath volumes at 6ml/kg). During thoracic surgery the anesthesiologist is able to ventilate only one lung by inserting a special breathing tube, allowing the surgeon to operate on the non ventilated (diseased) lung. In a randomized trial two interventions used to improve blood oxygen levels during one lung ventilation will be compared . The two interventions are:

1. Continuous Positive Airway Pressure (CPAP) applied to the non ventilated (non breathing) lung and
2. Positive End Expiratory Pressure following a lung Recruitment Maneuver (RM-PEEP) to the ventilated (breathing) lung.

CPAP is performed by applying a steady flow of oxygen to the non ventilated (non breathing) lung at a continuous gentle pressure of 5cmH20.

To perform a Recruitment Maneuver (RM) the anesthesiologist inflates the ventilated (breathing) lung with oxygen, holding the breath for 25 seconds so all the lung is opened up. Immediately after the recruitment maneuver PEEP will be applied. PEEP is an action which also helps keep the lung open, maintaining the benefits achieved by the RM. It is performed by adjusting settings on the ventilator (breathing machine). The ventilator creates and applies a gentle pressure (5cmH20) to the ventilating lung at the end of each breath.

The outcome measure will be the oxygen content in blood (PaO2), measured in mmHg, using blood sample analysis.

The null hypothesis is that compared to CPAP, RM-PEEP does not significantly increase the oxygen content of blood during OLV when using a lung protective ventilation strategy.

Detailed description: Patients requiring one lung ventilation (OLV) for open thoracic surgery will be ventilated intra-operatively using a lung protective ventilation strategy (small tidal volumes {Vts} at 6ml/kg Ideal Body Weight {IBW}). In a randomized, crossover trial Continuous Positive Airway Pressure (CPAP) to the non ventilated lung or a Recruitment Maneuver (RM) followed by the application of Positive End Expiratory Pressure (PEEP) (acronym RM-PEEP) to the ventilated lung will be applied and blood oxygenation (PaO2) measured by arterial blood gas sampling to determine which intervention has the most beneficial effect on PaO2 (CPAP or RM-PEEP).

CPAP will be applied at a pressure of 5cmH2O by a CPAP breathing circuit (designed for the purpose and commonly used in anesthetic practice). The PEEP will be applied at a pressure of 5cmH20 by the operating room (OR) anesthetic machine. The RM will involve a valsalva maneuver, held for 5 seconds at a pressure of 25cmH20, again performed using the OR anesthetic machine.

Null hypothesis: Compared to CPAP, RM-PEEP does not significantly increase PaO2 or reduce the incidence of hypoxia (oxygen blood saturation less than or equal to 90%), when employing a lung protective ventilation strategy.

This study is based on our previous research (citation 12, Badner et al) in which we compared CPAP to PEEP alone (omitting the recruitment maneuver). Here it was noted that CPAP to the non ventilated lung improved oxygenation more than PEEP to the ventilated lung (even though PEEP is an easier modality to provide), when employing a lung protective ventilation strategy.

Eligibility criteria: Inclusion Criteria:

1. Age 18 or older
2. Competent to give consent to enroll in study
3. Booked for scheduled open thoracotomy which involves wedge resection, lobectomy or pneumonectomy requiring OLV
4. American Society of Anesthesia physical status score (ASA) 1-4

Exclusion Criteria:

1. Unable to give consent
2. Pregnant women
3. Inability to insert an arterial line
4. Presence of other significant pulmonary impairment (PaO2 on room air \<50mmHg, PaCO2 \>50mmHg or known pulmonary hypertension (mean PAP\>25mmHg)
5. Presence of significant cardiovascular disease
6. Altered liver function (Child Pugh scale ≥B)
7. Patients with bullous lung disease. -

Primary outcomes:
measure: Partial pressure of oxygen in blood
timeFrame: Day 1
Secondary outcomes:
measure: Hypoxia
timeFrame: Day 1
measure: Hypoxia intervention techniques
timeFrame: Day 1
Other outcomes:
Locations:
city: London
country: Canada
facility: Victoria Hospital
state: Ontario
Study officials:
affiliation: London Health Sciences Centre Research Institute OR Lawson Research Institute of St. Joseph's
name: Neal Badner, MD FRCP (C)
role: PRINCIPAL_INVESTIGATOR
References:
citation: 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.
citation: Licker M, Diaper J, Villiger Y, Spiliopoulos A, Licker V, Robert J, Tschopp JM. Impact of intraoperative lung-protective interventions in patients undergoing lung cancer surgery. Crit Care. 2009;13(2):R41. doi: 10.1186/cc7762. Epub 2009 Mar 24.
citation: Schilling T, Kozian A, Huth C, Buhling F, Kretzschmar M, Welte T, Hachenberg T. The pulmonary immune effects of mechanical ventilation in patients undergoing thoracic surgery. Anesth Analg. 2005 Oct;101(4):957-965. doi: 10.1213/01.ane.0000172112.02902.77.
citation: Fernandez-Perez ER, Keegan MT, Brown DR, Hubmayr RD, Gajic O. Intraoperative tidal volume as a risk factor for respiratory failure after pneumonectomy. Anesthesiology. 2006 Jul;105(1):14-8. doi: 10.1097/00000542-200607000-00007.
citation: Licker M, de Perrot M, Spiliopoulos A, Robert J, Diaper J, Chevalley C, Tschopp JM. Risk factors for acute lung injury after thoracic surgery for lung cancer. Anesth Analg. 2003 Dec;97(6):1558-1565. doi: 10.1213/01.ANE.0000087799.85495.8A.
citation: Schultz MJ, Haitsma JJ, Slutsky AS, Gajic O. What tidal volumes should be used in patients without acute lung injury? Anesthesiology. 2007 Jun;106(6):1226-31. doi: 10.1097/01.anes.0000267607.25011.e8.
citation: Michelet P, D'Journo XB, Roch A, Doddoli C, Marin V, Papazian L, Decamps I, Bregeon F, Thomas P, Auffray JP. Protective ventilation influences systemic inflammation after esophagectomy: a randomized controlled study. Anesthesiology. 2006 Nov;105(5):911-9. doi: 10.1097/00000542-200611000-00011.
citation: Tusman G, Bohm SH, Sipmann FS, Maisch S. Lung recruitment improves the efficiency of ventilation and gas exchange during one-lung ventilation anesthesia. Anesth Analg. 2004 Jun;98(6):1604-1609. doi: 10.1213/01.ANE.0000068484.67655.1A.
citation: Fan E, Wilcox ME, Brower RG, Stewart TE, Mehta S, Lapinsky SE, Meade MO, Ferguson ND. Recruitment maneuvers for acute lung injury: a systematic review. Am J Respir Crit Care Med. 2008 Dec 1;178(11):1156-63. doi: 10.1164/rccm.200802-335OC. Epub 2008 Sep 5.
citation: Hoftman N, Canales C, Leduc M, Mahajan A. Positive end expiratory pressure during one-lung ventilation: selecting ideal patients and ventilator settings with the aim of improving arterial oxygenation. Ann Card Anaesth. 2011 Sep-Dec;14(3):183-7. doi: 10.4103/0971-9784.83991.
citation: Cohen E, Eisenkraft JB, Thys DM, Kirschner PA, Kaplan JA. Oxygenation and hemodynamic changes during one-lung ventilation: effects of CPAP10, PEEP10, and CPAP10/PEEP10. J Cardiothorac Anesth. 1988 Feb;2(1):34-40. doi: 10.1016/0888-6296(88)90145-7.
citation: Badner NH, Goure C, Bennett KE, Nicolaou G. Role of continuous positive airway pressure to the non-ventilated lung during one-lung ventilation with low tidal volumes. HSR Proc Intensive Care Cardiovasc Anesth. 2011;3(3):189-94.