External Dead Space in Ventilated COVID-19 Patients

NCT ID: NCT04424082

Last Updated: 2021-05-28

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 10 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2020-06-09
• Study Completion Date: 2021-05-27

Brief Summary

The objective is to investigate the efficacy of volumetric capnography to detect changes in dead space, CO2 elimination and shape factor parameters before and after disconnection of external dead space in ventilated COVID-19 patients.

Detailed Description

Covid-19 patients under mechanical ventilation are currently managed with a lung protective strategy derived from ARDSnet recommendations. In order to minimize the risk of spread of coronavirus, filters and associated respiratory tubing are incorporated to the breathing circuit, thus increasing apparatus dead space with subsequent increase in dead space ventilation. Considering the already often compromised ability for these patients to adequately clear carbon dioxide (VCO2), adding an external dead space can potentially have a substantial impact on CO2 homeostasis. The study will use volumetric capnography (Vcap) to investigate the influence of external dead space on VCO2 and calculated alveolar dead space.

Objective: 1) To investigate the efficacy of Vcap to detect changes in dead space, VCO2 and shape factor parameters before and after disconnection of external dead space.

2) To register the external dead space impact on arterial carbon dioxide tension (PaCO2).

3) To calculate the alveolar dead space based on Vcap data and arterial blood gas analysis results.

Design and setting: Prospective observational study in an intensive care center for Covid-19 patients in a university hospital.

Patients: Covid-19 positive patients of all age groups under mechanical ventilation. Exclusion criteria is ongoing ECMO treatment

Measurements and results: Vcap and Tcap parameters will be registered during mechanical ventilation and correlated to an arterial blood gas sample. Part of the apparatus dead space will then be reduced via removal of the heat and moister exchange filter (HME) with added tubing resulting in a reduction in volume of approximately 80 ml (i.e. the known volume of the HME filter and associated tubing). After the apparatus dead space is removed, the Vcap will be recorded for approximately 15 minutes and an arterial blood gas will be drawn at the end of the period. The HME and associated tubing will then be reattached to the breathing circuit and Vcap and Tcap parameters will be recorded for approximately 30 minutes and an arterial blood gas will be drawn. Vcap data will be analyzed for dead space, slope of phase III, VCO2 and associated shape factor parameters and compared with Tcap parameters. Changes in Vcap parameters will be tested for statistical significance using one and two-way ANOVA for repeated measures and Bland-Altman analysis will be used for comparison.

Conditions

Coronavirus; ARDS, Human

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: SUPPORTIVE_CARE
• Blinding Strategy: NONE

Study Groups

dead space removal

external dead space will be removed and Vcap parameters (VCO2, PaCO2 and alveolar dead space) recorded before and after.

Group Type: OTHER

Removal of dead space filter

Intervention Type: OTHER

Dead space filters will be removed and Vcap parameters (VCO2 ml/min, PaCO2 kPa, alveolar dead space in ml) recorded before and after removal

Interventions

Removal of dead space filter

Dead space filters will be removed and Vcap parameters (VCO2 ml/min, PaCO2 kPa, alveolar dead space in ml) recorded before and after removal

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

Covid-19 positive patients of all age groups under mechanical ventilation

-

• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Region Stockholm

OTHER_GOV

Sponsor Role: collaborator

Karolinska Institutet

OTHER

Sponsor Role: lead

Responsible Party

Jacob Karlsson

MD PhD

Responsibility Role: PRINCIPAL_INVESTIGATOR

Principal Investigators

Björn Persson, MD PhD

Role: STUDY_DIRECTOR

Karolinska University

Locations

Karolinska University Hospital

Stockholm, , Sweden

Countries

Sweden

Other Identifiers

Karolinska

Identifier Type: -

Identifier Source: org_study_id