Rationale: The Chartis® ( Pulmonx, CA, USA) measurement system is a tool to assess interlobar collateral ventilation during bronchoscopy. Assessing collateral ventilation is important when you intend to treat a patient with endobronchial valves. Chartis measurement of collateral ventilation can be performed under both conscious sedation as well as general anesthesia. There is no consensus on what is the preferred method of anesthesia for Chartis measurements in the literature.

Objective: In this project we want to investigate whether there is a difference in Chartis measurement outcomes between these two methods of anesthesia: conscious sedation and general anesthesia.

Study design: This study will be a single center observational study

Study population: The study population exists of patients with severe emphysema who undergo collateral ventilation assessment before bronchoscopic lung volume reduction treatment with one-way endobronchial valves.

Intervention: All patients will undergo two subsequent Chartis measurements. The first measurement will be performed with the patient undergoing conscious sedation and the second measurement with the patient under general anesthesia.

Main study parameters/endpoints: Our primary outcome measure is the failure rate of the Chartis collateral ventilation measurement under general anesthesia versus conscious sedation.

Inclusion Criteria:

• Patient is scheduled for a bronchoscopic lung volume treatment using one-way valves
• Patient has provided signed informed consent.

Exclusion Criteria:

For safety reasons patients that meet the following criteria will not be included in this study:

1. FEV1 <20%
2. RV/TLC>70%
3. pCO2 >6.5
4. RVSP>40mmHg
5. 6MWT<200m
6. Known intolerance to Lidocaine
7. Any other medical reason/condition that warrants a short procedure (physician judgement )

No plan to share IPD