Trial Outcomes & Findings for Physiology of Lung Collapse Under One-Lung Ventilation: Underlying Mechanisms (NCT NCT02919267)

NCT ID: NCT02919267

Last Updated: 2020-05-26

Results Overview

• Recruitment status: COMPLETED
• Study phase: NA
• Target enrollment: 40 participants
• Primary outcome timeframe: From the beginning of OLV until 60 minutes
• Results posted on: 2020-05-26

Participant Flow

As mentioned into the Methods section of the protocol, each patients that were excluded after randomization were replaced by a new randomized patient. We had to randomized 49 patients in order to analyze a total of 39 patients.

One patient was excluded after the study was completed because when we started the analysis of the results, we realized that one of the patient had an air leak during the study period that was not recognized by the investigator. Since the study was completed, we could not randomized a new patient.

Participant milestones

Measure	Intra-pulmonary Pressure Measurements With Double-lumen Tube For patients randomized to the intra-pulmonary pressure measurements, a pressure-tubing catheter was connected to the luerlock adaptor of the BB or to the adaptor located on the side of the occluding system mounted at the extremity of the DLT. The catheter was connected to a differential pressure transducer. Signals were amplified with a CD15 Carrier Demodulator then digitized at 5 Hz and sampled using an MP100 analogic/numeric system. Continuous pressure measurements were recorded before and after pleural opening by the surgeon. Tracings were recorded and subsequent off-line analyses were accomplished using ACQKnowledge and pressures were averaged every 30 seconds, excluding aberrant measures (above and below 2 SD of the mean).	Intra-pulmonary Pressure Determination With Bronchial Blocker For patients randomized to the intra-pulmonary pressure measurements, a pressure-tubing catheter was connected to the luerlock adaptor of the BB or to the adaptor located on the side of the occluding system mounted at the extremity of the DLT. The catheter was connected to a differential pressure transducer. Signals were amplified with a CD15 Carrier Demodulator then digitized at 5 Hz and sampled using an MP100 analogic/numeric system. Continuous pressure measurements were recorded before and after pleural opening by the surgeon. Tracings were recorded and subsequent off-line analyses were accomplished using ACQKnowledge and pressures were averaged every 30 seconds, excluding aberrant measures (above and below 2 SD of the mean).	Gas Movement Quantification With Double-lumen Tube For patients randomized to the gas movement quantification, a 2-liter bag was filled with 1000 mL of air with a 1000 mL calibrated syringe and a pneumotachometer through a 3-way valve prior to OLV. The pneumotachometer signal was amplified with Pneumotach Amplifier 1 and digitized at 200 Hz using MP100 analogic/numeric system. Volume were measured with ACQKnowledge by integration of flows measured with the pneumotachometer. One minute after initiation of OLV, the three-way valve was connected to the non-ventilated lumen of the DLT or to the internal chanel of the BB through an adaptor. Immediately prior to opening of the pleura, the volume measurement bag was closed and apnea was re-established in both groups for one minute as described above, after which measurements resumed for a total duration of 60 minutes of OLV. At the end of the observation period, the bag was emptied with the one-liter syringe through the pneumotachometer to measure its residual volume.	Gas Movement Quantification With Bronchial Blocker For patients randomized to the gas movement quantification, a 2-liter bag was filled with 1000 mL of air with a 1000 mL calibrated syringe and a pneumotachometer through a 3-way valve prior to OLV. The pneumotachometer signal was amplified with Pneumotach Amplifier 1 and digitized at 200 Hz using MP100 analogic/numeric system. Volume were measured with ACQKnowledge by integration of flows measured with the pneumotachometer. One minute after initiation of OLV, the three-way valve was connected to the non-ventilated lumen of the DLT or to the internal chanel of the BB through an adaptor. Immediately prior to opening of the pleura, the volume measurement bag was closed and apnea was re-established in both groups for one minute as described above, after which measurements resumed for a total duration of 60 minutes of OLV. At the end of the observation period, the bag was emptied with the one-liter syringe through the pneumotachometer to measure its residual volume.
Overall Study STARTED	10	12	13	14
Overall Study COMPLETED	10	9	10	10
Overall Study NOT COMPLETED	0	3	3	4

Reasons for withdrawal

Measure	Intra-pulmonary Pressure Measurements With Double-lumen Tube For patients randomized to the intra-pulmonary pressure measurements, a pressure-tubing catheter was connected to the luerlock adaptor of the BB or to the adaptor located on the side of the occluding system mounted at the extremity of the DLT. The catheter was connected to a differential pressure transducer. Signals were amplified with a CD15 Carrier Demodulator then digitized at 5 Hz and sampled using an MP100 analogic/numeric system. Continuous pressure measurements were recorded before and after pleural opening by the surgeon. Tracings were recorded and subsequent off-line analyses were accomplished using ACQKnowledge and pressures were averaged every 30 seconds, excluding aberrant measures (above and below 2 SD of the mean).	Intra-pulmonary Pressure Determination With Bronchial Blocker For patients randomized to the intra-pulmonary pressure measurements, a pressure-tubing catheter was connected to the luerlock adaptor of the BB or to the adaptor located on the side of the occluding system mounted at the extremity of the DLT. The catheter was connected to a differential pressure transducer. Signals were amplified with a CD15 Carrier Demodulator then digitized at 5 Hz and sampled using an MP100 analogic/numeric system. Continuous pressure measurements were recorded before and after pleural opening by the surgeon. Tracings were recorded and subsequent off-line analyses were accomplished using ACQKnowledge and pressures were averaged every 30 seconds, excluding aberrant measures (above and below 2 SD of the mean).	Gas Movement Quantification With Double-lumen Tube For patients randomized to the gas movement quantification, a 2-liter bag was filled with 1000 mL of air with a 1000 mL calibrated syringe and a pneumotachometer through a 3-way valve prior to OLV. The pneumotachometer signal was amplified with Pneumotach Amplifier 1 and digitized at 200 Hz using MP100 analogic/numeric system. Volume were measured with ACQKnowledge by integration of flows measured with the pneumotachometer. One minute after initiation of OLV, the three-way valve was connected to the non-ventilated lumen of the DLT or to the internal chanel of the BB through an adaptor. Immediately prior to opening of the pleura, the volume measurement bag was closed and apnea was re-established in both groups for one minute as described above, after which measurements resumed for a total duration of 60 minutes of OLV. At the end of the observation period, the bag was emptied with the one-liter syringe through the pneumotachometer to measure its residual volume.	Gas Movement Quantification With Bronchial Blocker For patients randomized to the gas movement quantification, a 2-liter bag was filled with 1000 mL of air with a 1000 mL calibrated syringe and a pneumotachometer through a 3-way valve prior to OLV. The pneumotachometer signal was amplified with Pneumotach Amplifier 1 and digitized at 200 Hz using MP100 analogic/numeric system. Volume were measured with ACQKnowledge by integration of flows measured with the pneumotachometer. One minute after initiation of OLV, the three-way valve was connected to the non-ventilated lumen of the DLT or to the internal chanel of the BB through an adaptor. Immediately prior to opening of the pleura, the volume measurement bag was closed and apnea was re-established in both groups for one minute as described above, after which measurements resumed for a total duration of 60 minutes of OLV. At the end of the observation period, the bag was emptied with the one-liter syringe through the pneumotachometer to measure its residual volume.
Overall Study Protocol Violation	0	3	3	4

Baseline Characteristics

Physiology of Lung Collapse Under One-Lung Ventilation: Underlying Mechanisms

Baseline characteristics by cohort

Measure	Intra-pulmonary Pressure Measurements With Double-lumen Tube n=10 Participants For patients randomized to the intra-pulmonary pressure measurements, a pressure-tubing catheter was connected to the luerlock adaptor of the BB or to the adaptor located on the side of the occluding system mounted at the extremity of the DLT. The catheter was connected to a differential pressure transducer. Signals were amplified with a CD15 Carrier Demodulator then digitized at 5 Hz and sampled using an MP100 analogic/numeric system. Continuous pressure measurements were recorded before and after pleural opening by the surgeon. Tracings were recorded and subsequent off-line analyses were accomplished using ACQKnowledge and pressures were averaged every 30 seconds, excluding aberrant measures (above and below 2 SD of the mean).	Intra-pulmonary Pressure Determination With Bronchial Blocker n=9 Participants For patients randomized to the intra-pulmonary pressure measurements, a pressure-tubing catheter was connected to the luerlock adaptor of the BB or to the adaptor located on the side of the occluding system mounted at the extremity of the DLT. The catheter was connected to a differential pressure transducer. Signals were amplified with a CD15 Carrier Demodulator then digitized at 5 Hz and sampled using an MP100 analogic/numeric system. Continuous pressure measurements were recorded before and after pleural opening by the surgeon. Tracings were recorded and subsequent off-line analyses were accomplished using ACQKnowledge and pressures were averaged every 30 seconds, excluding aberrant measures (above and below 2 SD of the mean).	Gas Movement Quantification With Double-lumen Tube n=10 Participants For patients randomized to the gas movement quantification, a 2-liter bag was filled with 1000 mL of air with a 1000 mL calibrated syringe and a pneumotachometer through a 3-way valve prior to OLV. The pneumotachometer signal was amplified with Pneumotach Amplifier 1 and digitized at 200 Hz using MP100 analogic/numeric system. Volume were measured with ACQKnowledge by integration of flows measured with the pneumotachometer. One minute after initiation of OLV, the three-way valve was connected to the non-ventilated lumen of the DLT or to the internal chanel of the BB through an adaptor. Immediately prior to opening of the pleura, the volume measurement bag was closed and apnea was re-established in both groups for one minute as described above, after which measurements resumed for a total duration of 60 minutes of OLV. At the end of the observation period, the bag was emptied with the one-liter syringe through the pneumotachometer to measure its residual volume.	Gas Movement Quantification With Bronchial Blocker n=10 Participants For patients randomized to the gas movement quantification, a 2-liter bag was filled with 1000 mL of air with a 1000 mL calibrated syringe and a pneumotachometer through a 3-way valve prior to OLV. The pneumotachometer signal was amplified with Pneumotach Amplifier 1 and digitized at 200 Hz using MP100 analogic/numeric system. Volume were measured with ACQKnowledge by integration of flows measured with the pneumotachometer. One minute after initiation of OLV, the three-way valve was connected to the non-ventilated lumen of the DLT or to the internal chanel of the BB through an adaptor. Immediately prior to opening of the pleura, the volume measurement bag was closed and apnea was re-established in both groups for one minute as described above, after which measurements resumed for a total duration of 60 minutes of OLV. At the end of the observation period, the bag was emptied with the one-liter syringe through the pneumotachometer to measure its residual volume.	Total n=39 Participants Total of all reporting groups
Age, Continuous	58 years STANDARD_DEVIATION 10 • n=5 Participants	67 years STANDARD_DEVIATION 7 • n=7 Participants	64 years STANDARD_DEVIATION 13 • n=5 Participants	64 years STANDARD_DEVIATION 13 • n=4 Participants	63 years STANDARD_DEVIATION 11 • n=21 Participants
Sex: Female, Male Female	7 Participants n=5 Participants	6 Participants n=7 Participants	8 Participants n=5 Participants	7 Participants n=4 Participants	28 Participants n=21 Participants
Sex: Female, Male Male	3 Participants n=5 Participants	3 Participants n=7 Participants	2 Participants n=5 Participants	3 Participants n=4 Participants	11 Participants n=21 Participants
Weight (kg)	73 kilograms STANDARD_DEVIATION 21 • n=5 Participants	76 kilograms STANDARD_DEVIATION 26 • n=7 Participants	66 kilograms STANDARD_DEVIATION 12 • n=5 Participants	65 kilograms STANDARD_DEVIATION 10 • n=4 Participants	70 kilograms STANDARD_DEVIATION 18 • n=21 Participants
Height (cm)	163 centimeters STANDARD_DEVIATION 7 • n=5 Participants	163 centimeters STANDARD_DEVIATION 10 • n=7 Participants	160 centimeters STANDARD_DEVIATION 10 • n=5 Participants	162 centimeters STANDARD_DEVIATION 12 • n=4 Participants	162 centimeters STANDARD_DEVIATION 10 • n=21 Participants
BMI (kg/m2)	28 kilograms/m^2 STANDARD_DEVIATION 8 • n=5 Participants	28 kilograms/m^2 STANDARD_DEVIATION 7 • n=7 Participants	26 kilograms/m^2 STANDARD_DEVIATION 5 • n=5 Participants	25 kilograms/m^2 STANDARD_DEVIATION 4 • n=4 Participants	27 kilograms/m^2 STANDARD_DEVIATION 6 • n=21 Participants
Forced expiratory volume in one second (FEV1) (% of predicted)	86 % of predicted value STANDARD_DEVIATION 21 • n=5 Participants	90 % of predicted value STANDARD_DEVIATION 14 • n=7 Participants	92 % of predicted value STANDARD_DEVIATION 20 • n=5 Participants	93 % of predicted value STANDARD_DEVIATION 20 • n=4 Participants	90 % of predicted value STANDARD_DEVIATION 18 • n=21 Participants
Time tu pleural opening (min)	14 minutes STANDARD_DEVIATION 6 • n=5 Participants	12 minutes STANDARD_DEVIATION 6 • n=7 Participants	12 minutes STANDARD_DEVIATION 4 • n=5 Participants	14 minutes STANDARD_DEVIATION 4 • n=4 Participants	13 minutes STANDARD_DEVIATION 5 • n=21 Participants
Side of surgery (R/L) Right-sided surgery	7 Participants n=5 Participants	6 Participants n=7 Participants	6 Participants n=5 Participants	5 Participants n=4 Participants	24 Participants n=21 Participants
Side of surgery (R/L) Left-sided surgery	3 Participants n=5 Participants	3 Participants n=7 Participants	4 Participants n=5 Participants	5 Participants n=4 Participants	15 Participants n=21 Participants

PRIMARY outcome

Timeframe: From the beginning of OLV until 60 minutes

Outcome measures

Measure	Gas Movement Quantification With Double-lumen Tube n=10 Participants For patients randomized to the gas movement quantification, a 2-liter bag was filled with 1000 mL of air with a 1000 mL calibrated syringe and a pneumotachometer through a 3-way valve prior to OLV. The pneumotachometer signal was amplified with Pneumotach Amplifier 1 and digitized at 200 Hz using MP100 analogic/numeric system. Volume were measured with ACQKnowledge by integration of flows measured with the pneumotachometer. One minute after initiation of OLV, the three-way valve was connected to the non-ventilated lumen of the DLT or to the internal chanel of the BB through an adaptor. Immediately prior to opening of the pleura, the volume measurement bag was closed and apnea was re-established in both groups for one minute as described above, after which measurements resumed for a total duration of 60 minutes of OLV. At the end of the observation period, the bag was emptied with the one-liter syringe through the pneumotachometer to measure its residual volume.	Gas Movement Quantification With Bronchial Blocker n=10 Participants For patients randomized to the gas movement quantification, a 2-liter bag was filled with 1000 mL of air with a 1000 mL calibrated syringe and a pneumotachometer through a 3-way valve prior to OLV. The pneumotachometer signal was amplified with Pneumotach Amplifier 1 and digitized at 200 Hz using MP100 analogic/numeric system. Volume were measured with ACQKnowledge by integration of flows measured with the pneumotachometer. One minute after initiation of OLV, the three-way valve was connected to the non-ventilated lumen of the DLT or to the internal chanel of the BB through an adaptor. Immediately prior to opening of the pleura, the volume measurement bag was closed and apnea was re-established in both groups for one minute as described above, after which measurements resumed for a total duration of 60 minutes of OLV. At the end of the observation period, the bag was emptied with the one-liter syringe through the pneumotachometer to measure its residual volume.
Quantification of Gas Volume Coming From Ambient Air Towards the Alveoli Space of the Non-ventilated Lung During OLV With the Use of DLT and BB.	504 milliliters (mL) Standard Error 85	630 milliliters (mL) Standard Error 86

SECONDARY outcome

Timeframe: From the beginning until 10 minutes of OLV

Intra-pulmonary pressure measured from initiation of OLV to pleural opening were similarly analyzed using a two-way ANOVA. Two experimental factors, one associated to the comparison between two groups (DLT versus BB), factor fixed and one associated to the comparison among results from the time periods (0 to 10 minutes), factor fixed with interaction terms between the fixed factors were defined. The data was analyzed using a repeated mixed model. An autoregressive covariance structure was used to consider the dependency among repeated measurements.

Outcome measures

Measure	Gas Movement Quantification With Double-lumen Tube n=9 Participants For patients randomized to the gas movement quantification, a 2-liter bag was filled with 1000 mL of air with a 1000 mL calibrated syringe and a pneumotachometer through a 3-way valve prior to OLV. The pneumotachometer signal was amplified with Pneumotach Amplifier 1 and digitized at 200 Hz using MP100 analogic/numeric system. Volume were measured with ACQKnowledge by integration of flows measured with the pneumotachometer. One minute after initiation of OLV, the three-way valve was connected to the non-ventilated lumen of the DLT or to the internal chanel of the BB through an adaptor. Immediately prior to opening of the pleura, the volume measurement bag was closed and apnea was re-established in both groups for one minute as described above, after which measurements resumed for a total duration of 60 minutes of OLV. At the end of the observation period, the bag was emptied with the one-liter syringe through the pneumotachometer to measure its residual volume.	Gas Movement Quantification With Bronchial Blocker n=10 Participants For patients randomized to the gas movement quantification, a 2-liter bag was filled with 1000 mL of air with a 1000 mL calibrated syringe and a pneumotachometer through a 3-way valve prior to OLV. The pneumotachometer signal was amplified with Pneumotach Amplifier 1 and digitized at 200 Hz using MP100 analogic/numeric system. Volume were measured with ACQKnowledge by integration of flows measured with the pneumotachometer. One minute after initiation of OLV, the three-way valve was connected to the non-ventilated lumen of the DLT or to the internal chanel of the BB through an adaptor. Immediately prior to opening of the pleura, the volume measurement bag was closed and apnea was re-established in both groups for one minute as described above, after which measurements resumed for a total duration of 60 minutes of OLV. At the end of the observation period, the bag was emptied with the one-liter syringe through the pneumotachometer to measure its residual volume.
Measurement of Intra-pulmonary Pressure in the Non-ventilated Lung With the Use of DLT and BB 0 minutes	0 cmH2O Standard Error 0	0 cmH2O Standard Error 0
Measurement of Intra-pulmonary Pressure in the Non-ventilated Lung With the Use of DLT and BB 1 minutes	-1.1 cmH2O Standard Error 0.3	-0.7 cmH2O Standard Error 1.2
Measurement of Intra-pulmonary Pressure in the Non-ventilated Lung With the Use of DLT and BB 2 minutes	-2.4 cmH2O Standard Error 0.4	-2.6 cmH2O Standard Error 1.7
Measurement of Intra-pulmonary Pressure in the Non-ventilated Lung With the Use of DLT and BB 3 minutes	-3.7 cmH2O Standard Error 0.6	-4.9 cmH2O Standard Error 2.6
Measurement of Intra-pulmonary Pressure in the Non-ventilated Lung With the Use of DLT and BB 4 minutes	-5.2 cmH2O Standard Error 0.9	-8.9 cmH2O Standard Error 4.5
Measurement of Intra-pulmonary Pressure in the Non-ventilated Lung With the Use of DLT and BB 5 minutes	-6.9 cmH2O Standard Error 1.3	-11.9 cmH2O Standard Error 5.6
Measurement of Intra-pulmonary Pressure in the Non-ventilated Lung With the Use of DLT and BB 6 minutes	-8.8 cmH2O Standard Error 1.8	-14.2 cmH2O Standard Error 8
Measurement of Intra-pulmonary Pressure in the Non-ventilated Lung With the Use of DLT and BB 7 minutes	-10.7 cmH2O Standard Error 2.3	-18.1 cmH2O Standard Error 9.4
Measurement of Intra-pulmonary Pressure in the Non-ventilated Lung With the Use of DLT and BB 8 minutes	-13.6 cmH2O Standard Error 3.1	-19.7 cmH2O Standard Error 9.2
Measurement of Intra-pulmonary Pressure in the Non-ventilated Lung With the Use of DLT and BB 9 minutes	-16.3 cmH2O Standard Error 3.8	-24.6 cmH2O Standard Error 12.0
Measurement of Intra-pulmonary Pressure in the Non-ventilated Lung With the Use of DLT and BB 10 minutes	-20.6 cmH2O Standard Error 4.9	-28.3 cmH2O Standard Error 13.6

Adverse Events

Intra-pulmonary Pressure Measurements With Double-lumen Tube

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Intra-pulmonary Pressure Determination With Bronchial Blocker

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Gas Movement Quantification With Double-lumen Tube

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Gas Movement Quantification With Bronchial Blocker

Serious events: 0 serious events

Other events: 0 other events

Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Adverse event data not reported

Additional Information

Dr Jean Bussières

Institut universitaire de cardiologie de de pneumologie de Québec

Phone: 418-656-8711

Email: jbuss@criucpq.ulaval.ca

Results disclosure agreements

• Principal investigator is a sponsor employee
• Publication restrictions are in place