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

Thoracic Surgery Clinical Trial

— PLC-OLV  

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02919267
• Other study ID #: IUCPQ 21299
• Status: Completed
• Phase: N/A
• Start date: September 2016
• Est. completion date: December 2016

Study information

• Verified date: May 2020
• Source: Laval University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Lung isolation technique and one-lung ventilation (OLV) are the mainstays of thoracic anesthesia. Two principal lung isolation techniques are mainly use by clinicians, the double lumen tubes (DLT) and the bronchial blockers (BB). The physiology of lung collapse during OLV is not well described in the literature. Few publications characterized scant aspects of lung collapse, only with the use of DLT and sometime in experimental animals. Two phases of lung collapse have been described. The first phase is a quick and partial secondary to the intrinsic recoil of the lung. The second phase is the reabsorption of gas contained in the alveoli by the capillary bed. The investigators plan to describe the physiology of the second phase of lung deflation using of DLT or BB, in a human clinical context.

Description:

Lung isolation and one-lung ventilation (OLV) have been used for more than 60 years, principally via double lumen endotracheal tubes (DLT). Since the beginning of the 21st century, modernisation of bronchial blockers (BB) has favoured their more frequent use. Meanwhile, video assisted thoracoscopic surgery (VATS) has increased, becoming the standard for the majority of intra-thoracic pulmonary surgeries.

Lung collapse during OLV undergoes two distinct phases. The first phase occurs at the opening of the pleural cavity and corresponds to a quick but partial collapse of the lung due to its intrinsic recoil. This phase probably ends when small airways are closed. Thereafter, the second phase, a slower one, corresponds to the reabsorption, by the capillary bed, of gas contained into the alveoli. The speed of this reabsorption depends on the solubility of the gas contained in the alveoli.

Intriguingly, the physiology of lung collapse under OLV remains poorly understood, especially with the use of BB. Theoretically, many aspects of lung isolation may influence lung collapse, including the ventilation strategy before OLV, the timing and the lung isolation devices being used. While oxygen at 100% is widely used for ventilation before OLV, the timing of initiation of lung isolation varies from centers to centers. Indeed, the most conservative will begin the lung isolation just before the opening of the pleural space, whereas others begin the lung isolation following the appropriate positioning of the patient and confirmation that the lung isolation device is properly positioned by fiberoptic bronchoscopy (FOB) examination. Therefore, the period between initiation of lung isolation and pleural opening may vary from a few minutes to >30 minutes. The mechanic of lung isolation differs between DLT and BB and consequently the physiology of lung deflation may be different. When using DLT, the lumen that corresponds to the collapsed lung is disconnected from the ventilator and is continuously in communication with the ambient air. When using BB a bronchial cuff is inflated within the main bronchus following a 30 seconds apnea period, allowing the initial lung deflation to be mediated by elastic lung recoil. After this initial phase, the only communication with ambient air is through the small (2 mm) and long internal (67 mm) channel, which is completely different from the larger lumen of the DLT.

Rapid and complete lung collapse is essential during lung isolation for VATS otherwise; there is no alternative available for the surgeon to get proper view of the pulmonary hilum. Previous studies suggested that BB allow a less effective lung collapse than the one obtained with DLT. However, the authors recently documented that the use of BB with its internal channel occluded creates a statistically significant shorter time to complete lung collapse during VATS compared to DLT (36.6 ± 29.1 vs 7.5 ± 3.8 min; p<0.001). In contrast to the previous studies, the authors used off-line review videos recorded during the surgery to obtain a more objective evaluation of the complete lung collapse time which probably reflected the second phase of lung deflation. Although, our definition of lung collapse was very strict, meaning complete collapse of all the lung areas, graded using a standardized visual scale and chart. However, authors do not have any data to explain why this internal channel occlusion may have some positive impact. The authors hypothesized that their results could be explained by the optimisation of the reabsorption phases following enhanced atelectasis by gas reabsorption (phase 2) after bronchial blockade. This latter hypothesis is supported by a pilot observation that ambient air (FiO2 at 0.21) was "sucked up" within the collapsing lung when using DLT to a greater extent than with the use of BB (unpublished data). The presence of ambient air (21%) in the alveolar space may likely slowing subsequent gas reabsorption compared to intra-alveolar 100% O2 . However, these hypotheses remain to be confirmed.

The investigators proposed this study to update the knowledge about lung collapse with the actual lung isolation devices: DLT and BB. This protocol will describe the lung collapse physiology and allows getting data for the elaboration of further studies.

Thus the present hypothesis is that during the second phase of lung collapse, the inflow of air through the lumen of the non-ventilated lung of the DLT is greater than through the internal channel of the BB, in the course of lung isolation for OLV.

The main objective of this study is the gas volume quantification (GVQ) coming from ambient air towards the alveoli space of the non-ventilated lung during OLV with the use of DLT and BB. These measurements will be performed from the beginning of OLV until 60 minutes after, meaning approximatively 45 minutes after the opening of the pleura by the surgeon. The secondary objective is the intra-pulmonary pressure measurement (IPM) in the non-ventilated lung with the use of DLT and BB during the same period.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 40
• Est. completion date: December 2016
• Est. primary completion date: December 2016
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• elective unilateral lung resection (anatomical segmentectomy, lobectomy or pneumonectomy) for lung cancer

Exclusion Criteria:

• anticipated difficult mask ventilation or intubation

• pleural pathology

• previous thoracic surgery

• previous sternotomy

• previous chemotherapy or chest radiotherapy

• severe COPD or asthma (FEV1 = 50%)

• active or chronic pulmonary infection

• endobronchial mass

• tracheostomy

Post randomisation exclusion criteria :

• severe desaturation before or during the observation period

• any clinical situation precluding the use of one of the lung isolation device

• air leak at the level of bronchial isolation

Related Conditions & MeSH terms

• Lung Collapse
• One-Lung Ventilation
• Pulmonary Atelectasis
• Shock
• Thoracic Surgery
• Video-Assisted

Intervention

Device:
• Double lumen tube
Either gaseous volume quantification or intrapulmonary pressure measurements will be done in patients randomized in the L-DLT group.
• Bronchial blocker
Either gaseous volume quantification or intrapulmonary pressure measurements will be done in patients randomized in the BB group.

Locations

Country	Name	City	State
Canada	Institut universitaire de cardiologie et de pneumologie de Québec	Québec

Sponsors (1)

Lead Sponsor	Collaborator
Laval University

Country where clinical trial is conducted

Canada, 

References & Publications (18)

Bauer C, Winter C, Hentz JG, Ducrocq X, Steib A, Dupeyron JP. Bronchial blocker compared to double-lumen tube for one-lung ventilation during thoracoscopy. Acta Anaesthesiol Scand. 2001 Feb;45(2):250-4. — View Citation

Brodsky JB, Lemmens HJ. Tracheal width and left double-lumen tube size: a formula to estimate left-bronchial width. J Clin Anesth. 2005 Jun;17(4):267-70. — View Citation

Bussières JS, Somma J, Del Castillo JL, Lemieux J, Conti M, Ugalde PA, Gagné N, Lacasse Y. Bronchial blocker versus left double-lumen endotracheal tube in video-assisted thoracoscopic surgery: a randomized-controlled trial examining time and quality of lung deflation. Can J Anaesth. 2016 Jul;63(7):818-27. doi: 10.1007/s12630-016-0657-3. Epub 2016 May 2. — View Citation

Campos JH, Kernstine KH. A comparison of a left-sided Broncho-Cath with the torque control blocker univent and the wire-guided blocker. Anesth Analg. 2003 Jan;96(1):283-9, table of contents. — View Citation

Campos JH, Reasoner DK, Moyers JR. Comparison of a modified double-lumen endotracheal tube with a single-lumen tube with enclosed bronchial blocker. Anesth Analg. 1996 Dec;83(6):1268-72. — View Citation

Clayton-Smith A, Bennett K, Alston RP, Adams G, Brown G, Hawthorne T, Hu M, Sinclair A, Tan J. A Comparison of the Efficacy and Adverse Effects of Double-Lumen Endobronchial Tubes and Bronchial Blockers in Thoracic Surgery: A Systematic Review and Meta-analysis of Randomized Controlled Trials. J Cardiothorac Vasc Anesth. 2015 Aug;29(4):955-66. doi: 10.1053/j.jvca.2014.11.017. Epub 2014 Dec 2. Review. — View Citation

Dumans-Nizard V, Liu N, Laloë PA, Fischler M. A comparison of the deflecting-tip bronchial blocker with a wire-guided blocker or left-sided double-lumen tube. J Cardiothorac Vasc Anesth. 2009 Aug;23(4):501-5. doi: 10.1053/j.jvca.2009.02.002. Epub 2009 Apr 10. — View Citation

Fortier G, Coté D, Bergeron C, Bussières JS. New landmarks improve the positioning of the left Broncho-Cath double-lumen tube-comparison with the classic technique. Can J Anaesth. 2001 Sep;48(8):790-4. — View Citation

Joyce CJ, Baker AB, Kennedy RR. Gas uptake from an unventilated area of lung: computer model of absorption atelectasis. J Appl Physiol (1985). 1993 Mar;74(3):1107-16. — View Citation

Joyce CJ, Baker AB, Parkinson R, Zacharias M. Nitrous oxide and the rate of gas uptake from an unventilated lung in dogs. Br J Anaesth. 1996 Feb;76(2):292-6. — View Citation

Ko R, McRae K, Darling G, Waddell TK, McGlade D, Cheung K, Katz J, Slinger P. The use of air in the inspired gas mixture during two-lung ventilation delays lung collapse during one-lung ventilation. Anesth Analg. 2009 Apr;108(4):1092-6. doi: 10.1213/ane.0b013e318195415f. — View Citation

Kovacs G, Avian A, Olschewski A, Olschewski H. Zero reference level for right heart catheterisation. Eur Respir J. 2013 Dec;42(6):1586-94. doi: 10.1183/09031936.00050713. Epub 2013 Jun 21. — View Citation

Merchant R, Chartrand D, Dain S, Dobson J, Kurrek M, LeDez K, Morgan P, Shukla R; Canadian Anesthesiologists' Society. Guidelines to the Practice of Anesthesia Revised Edition 2012. Can J Anaesth. 2012 Jan;59(1):63-102. doi: 10.1007/s12630-011-9609-0. English, French. — View Citation

Pfitzner J, Peacock MJ, Harris RJ. Speed of collapse of the non-ventilated lung during single-lung ventilation for thoracoscopic surgery: the effect of transient increases in pleural pressure on the venting of gas from the non-ventilated lung. Anaesthesia. 2001 Oct;56(10):940-6. — View Citation

Pfitzner J, Peacock MJ, McAleer PT. Gas movement in the nonventilated lung at the onset of single-lung ventilation for video-assisted thoracoscopy. Anaesthesia. 1999 May;54(5):437-43. — View Citation

Pfitzner J, Peacock MJ, Pfitzner L. Speed of collapse of the non-ventilated lung during one-lung anaesthesia: the effects of the use of nitrous oxide in sheep. Anaesthesia. 2001 Oct;56(10):933-9. — View Citation

Shah RD, D'Amico TA. Modern impact of video assisted thoracic surgery. J Thorac Dis. 2014 Oct;6(Suppl 6):S631-6. doi: 10.3978/j.issn.2072-1439.2014.08.02. Review. — View Citation

Yoshimura T, Ueda K, Kakinuma A, Sawai J, Nakata Y. Bronchial blocker lung collapse technique: nitrous oxide for facilitating lung collapse during one-lung ventilation with a bronchial blocker. Anesth Analg. 2014 Mar;118(3):666-70. doi: 10.1213/ANE.0000000000000106. — View Citation

* Note: There are 18 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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.		From the beginning of OLV until 60 minutes
Secondary	Measurement of Intra-pulmonary Pressure in the Non-ventilated Lung With the Use of DLT and BB	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.	From the beginning until 10 minutes of OLV