Nitrous Oxide for Identifying the Intersegmental Plane in Segmentectomy: A Randomized Controlled Trial

Not Applicable

Completed

Conditions: Lung Cancer
Pulmonary Nodule, Solitary
Pulmonary Nodule, Multiple

Interventions: Procedure: nitrous oxide

Registration Number: NCT04302350

Lead Sponsor: The First Affiliated Hospital with Nanjing Medical University

Brief Summary: Lung cancer is currently one of the most common malignant tumors in the world. In recent years, with the popularity of high-resolution CT, more and more early-stage lung cancers have been found. Anatomic pneumonectomy is gradually popular because it can completely remove lung nodules and preserve lung function to the greatest extent. During the surgery, the precise and rapid determination of intersegmental border is one of the key technologies. Improved inflation-deflation method is currently the most widely used method in clinical practice. Previous studies demonstrated that increasing the concentration of nitrous oxide in mixtures of N2O/O2 will lead to a faster rate of collapse. The rapid diffusion properties of N2O would be expected to speed lung collapse and so facilitate surgery. This study was designed to explore three types of inspired gas mixture used during two-lung anesthesia had an effect on the intersegmental border appearance time during pneumonectomy and its feasibility and safety: 75% N2O (O2: N2O = 1: 3), 50% N2O (O2: N2O = 1: 1), 100% oxygen.

Detailed Description: This randomized parallel group trial enrolled lung cancer patients scheduled to receive thoracoscopic anatomic segmentectomy at The First Affiliated Hospital of Nanjing Medical University. When anesthesia induction was completed, intubation was carried out using an appropriate-size double-lumen endobronchial tube (DLT) and the position of the DLT was confirmed with fiberoptic bronchoscopy and adjusted as needed. OLV of the dependent lung with FiO2=1.0 was begun in the lateral position, by clamping the DLT to the nonventilated lung proximally and opening the distal port of the DLT lumen to the atmosphere. Tidal volumes were 5 mL/kg ideal bodyweight (male: height -100, and female: height - 105) without positive end expiratory pressure (PEEP). In order to avoid possible confounding effects of inhalation of volatile anesthetics on oxygenation, all subjects received total intravenous anesthesia.

According to preoperative 3D-CTBA evaluation of bronchial and vascular structure of pulmonary nodules and pulmonary segments, the target segmental bronchus, arteries and intra-segment veins were accurately identi-fied and dissected by ligation or stapler cutting. After that, the anesthesiologist began to make preparations for the lung inflation. The portable nitrous oxide concentration detector (TD600-SH-B-N2O) was installed to detect N2O concentration (vol%), and then adjusted the anesthesia machine to the manual control mode. The flow of the selected gas mixture was set to 8L/min (Group75 set to N2O:O2=6:2, Group50 set to N2O:O2=4:4, Group0 set to O2=8), avoiding the interference of the total gas flow. When the N2O concentration detector reached the predetermined gas concentration, and then the collapsed lung was re-expanded completely with controlled airway pressure under 20 cmH2O (1cm H2O=0.098 kPa) by the anesthesiologist. This procedure took approximately 1 min, and then FiO2=1.0 was performed after the initiation of the OLV.

Recruitment & Eligibility

Status: COMPLETED

Sex: All

Target Recruitment: 81

Inclusion Criteria

1、20 to 70 years of age; 2、early stage lung cancer（diameter of tumor consolidation ≤ 2cm, none evidence of lymph node or distant metas-tasis, c-stage ⅠA1 or ⅠA2）（active limited resection）； 3、 patients at high risk due to poor general condition who cannot undergo lobectomy (c-stage IA1 to IA3) (passive limited resection)

Exclusion Criteria

a history of severe asthma or pneumothorax；
pulmonary bullae on chest CT；
patient refusal

Study & Design

Study Type: INTERVENTIONAL

Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Group75	nitrous oxide	According to preoperative 3D-CTBA evaluation of bronchial and vascular structure of pulmonary nodules and pulmonary segments, the target segmental bronchus, arteries and intra-segment veins were accurately identified and dissected by ligation or stapler cutting. After that, the anesthesiologist began to make preparations for the lung inflation. The portable nitrous oxide concentration detector (TD600-SH-B-N2O) was installed to detect N2O concentration (vol%), and then adjusted the anesthesia machine to the manual control mode. The flow of the selected gas mixture was set to 8L/min (Group75 set to N2O:O2=6:2). When the N2O concentration detector reached the predetermined gas concentration, and then the collapsed lung was re-expanded completely with controlled airway pressure under 20 cmH2O (1cm H2O=0.098 kPa) by the anesthesiologist. This procedure took approximately 1 min, and then FiO2=1.0 was performed after the initiation of the OLV.
Group0	nitrous oxide	According to preoperative 3D-CTBA evaluation of bronchial and vascular structure of pulmonary nodules and pulmonary segments, the target segmental bronchus, arteries and intra-segment veins were accurately identified and dissected by ligation or stapler cutting. After that, the anesthesiologist began to make preparations for the lung inflation. The portable nitrous oxide concentration detector (TD600-SH-B-N2O) was installed to detect N2O concentration (vol%), and then adjusted the anesthesia machine to the manual control mode. The flow of the selected gas mixture was set to 8L/min (Group0 set to O2=8). When the N2O concentration detector reached the predetermined gas concentration, and then the collapsed lung was re-expanded completely with controlled airway pressure under 20 cmH2O (1cm H2O=0.098 kPa) by the anesthesiologist. This procedure took approximately 1 min, and then FiO2=1.0 was performed after the initiation of the OLV.
Group50	nitrous oxide	According to preoperative 3D-CTBA evaluation of bronchial and vascular structure of pulmonary nodules and pulmonary segments, the target segmental bronchus, arteries and intra-segment veins were accurately identified and dissected by ligation or stapler cutting. After that, the anesthesiologist began to make preparations for the lung inflation. The portable nitrous oxide concentration detector (TD600-SH-B-N2O) was installed to detect N2O concentration (vol%), and then adjusted the anesthesia machine to the manual control mode. The flow of the selected gas mixture was set to 8L/min (Group50 set to N2O:O2=4:4). When the N2O concentration detector reached the predetermined gas concentration, and then the collapsed lung was re-expanded completely with controlled airway pressure under 20 cmH2O (1cm H2O=0.098 kPa) by the anesthesiologist. This procedure took approximately 1 min, and then FiO2=1.0 was performed after the initiation of the OLV.

Primary Outcome Measures

Name	Time	Method
The Intersegmental Border Appearance Time During the Surgery	The time of appearance of the intersegmental plane that can be performed satisfactorily by surgeons	The starting point of intraoperative expansion and collapse observation is the time when the lung tissue is completely expanded after blocking the relevant structure of the target segment; the end point is when a clear demarcation is formed between the target segment and the immediately-reserved lung segment, and this boundary does not follow significant changes over time), and the time was recorded in seconds (S).

Secondary Outcome Measures

Name	Time	Method

Trial Locations

Locations (2): The First Affiliated Hospital with Nanjing Medical University
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Nanjing, Jiangsu, China
The First Affiliated Hospital of Nanjing Medical University
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Nanjing, Jiangsu, China