AtelectasisNCT03351946
Zero Positive End-expiratory Pressure Before Emergence Prevents Postoperative Atelectasis.
A study testing ZEEP and PEEP in people with Atelectasis and Oxygenation, run by Region Västmanland at 1 site in Sweden.
Trial summary
A study on healthy patients undergoing anesthesia for non-abdominal surgery - evaluation of positive end-expiratory pressure versus zero positive end-expiratory pressure on the amount of atelectasis in the early postoperative period. Read more about this study
- Who is it for?
- Ages 40 to 75 years
- Conditions the study is for
- Atelectasis, Oxygenation
- What is being tested?
- ZEEP and PEEP
- Type of treatment
- Surgery or procedure
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 30 participants
- Where
- 1 siteSweden
- Study dates
- 4 Dec 2017to 28 Aug 2018
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 40 to 75 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- American Society of Anesthesiology (ASA) class I-II
- Non-abdominal day case surgery under general anesthesia
Who cannot join
- Body mass index (BMI) ≥30 kg/m2
- Arterial oxygen saturation (SpO2) breathing air <95 %
- Chronic Obstructive Pulmonary Disease (COPD) or symptomatic asthma
- Symptomatic congestive heart failure
- Ischemic heart disease
- Hemoglobin <100 g/L
Show all 9Show fewer
- Active smokers
- Active smokers and ex-smokers with a history of more than 6 pack years.
- Need for interscalene or supraclavicular plexus block for postoperative pain relief (risk of phrenic nerve paralysis).
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Zero Positive End-expiratory Pressure Applied Before Emergence Preoxygenation Prevents Postoperative Atelectasis - a Randomized Controlled Trial.
A study on healthy patients undergoing anesthesia for non-abdominal surgery - evaluation of positive end-expiratory pressure versus zero positive end-expiratory pressure on the amount of atelectasis in the early postoperative period.
Read the detailed description
Positive end-expiratory pressure (PEEP) is often used during mechanical ventilation to preserve end-expiratory lung volume. After emergence and extubation, this volume will diminish instantly. Some patients will have difficulties to restore functional residual capacity (FRC) during the early phase of recovery. If routine high FIO2 has been delivered together with maintained PEEP prior to extubation, several important prerequisites are established for the development of postoperative atelectasis. The investigators hypothesize that establishing zero positive end-expiratory pressure (ZEEP) immediately prior to emergence preoxygenation, will prevent gas with high oxygen concentration from entering dorso-basal areas of the lungs, and thereby prevent postoperative atelectasis formation.
This randomized controlled study will study patients undergoing non-abdominal day case surgeries under general anesthesia. The patients in the two study groups will receive mechanical ventilation with identical settings, comprising low TV, moderate PEEP, and no RM. At the end of surgery, the lungs will be examined by CT, and any atelectasis areas will be calculated. Randomization will occur after the first CT. The patients will be allocated to zero PEEP (ZEEP) or maintained PEEP during emergence preoxygenation and extubation. Importantly, the intervention group will have ZEEP established while still having low ETO2 levels, prior to any preoxygenation. The study subjects will be examined with CT no.2 approximately thirty min after extubation. Primary endpoint measure will be atelectasis area as a percentage of total lung area. Blood gases will be collected for comparison of oxygenation as a secondary outcome measure.
- Conditions
- Atelectasis, Oxygenation
- Being tested
- ZEEP, PEEP
- Keywords
- Atelectasis, Oxygenation, Positive end-expiratory pressure, Mechanical ventilation, General anesthesia, Computed tomography
- Medical subject headings
- Pulmonary Atelectasis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
ZEEPProcedure or surgery
Also called Device: Ventilatory setting ZEEP
Zero positive end-expiratory pressure (ZEEP) during emergence preoxygenation and awakening.
PEEPProcedure or surgery
Also called Device: Ventilatory setting PEEP
Positive end-expiratory pressure remains during emergence preoxygenation and awakening and until the study subject is extubated.
| Study group | Role | What they receive |
|---|---|---|
| ZEEP at awakening | Active comparator | Controlled ventilation with tidal volume of 7 mL/kg of ideal body weight and respiratory frequency 10. Fresh gas flow is set to 1 litre/min with an oxygen mixture of 40%, aiming for an inspired oxygen fraction (FiO2) of 30-35%. Positive end-expiratory pressure (PEEP) is set to 7 or 9 cm H20 (9 if BMI≥25) until start of emergence preoxygenation.
Unless the patient´s SpO2 falls below 90%, the FiO2 remains unchanged throughout the procedure.
First CT scan after completion of surgery, before emergence. After the first CT scan and immediately before start of emergence preoxygenation, this group will have the PEEP exchanged for zero PEEP (ZEEP). ZEEP will remain until the study subjects are extubated. Second CT scan approx. 30 min after extubation. Receives: Procedure: ZEEP |
| PEEP at awakening | Active comparator | Controlled ventilation with tidal volume of 7 mL/kg of ideal body weight and respiratory frequency 10. Fresh gas flow is set to 1 litre/min with an oxygen mixture of 40%, aiming for an inspired oxygen fraction (FiO2) of 30-35%. Positive end-expiratory pressure (PEEP) is set to 7 or 9 cm H20 (9 if BMI≥25) even after start of emergence preoxygenation.
Unless the patient´s SpO2 falls below 90%, the FiO2 remains unchanged throughout the procedure.
First CT scan after completion of surgery, before emergence. After the first CT scan, this group will have PEEP remained until the study subjects are extubated. Second CT scan approx. 30 min after extubation. Receives: Procedure: PEEP |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in atelectasis area
Atelectasis area as studied by computed tomography.
Measured: Within 3 hours from induction of anesthesia. First CT after surgery, before emergence. Second CT approx 25 min after extubation. Study complete after that, no further CT.
Secondary outcomes (1)
Change in oxygenation
Arterial blood samples will be collected for measurement of arterial oxygen partial pressure.
Measured: Within 3 hours from induction of anesthesia. First blood gas after surgery, before emergence. Second approx 25 min after extubation. Study complete after that, no further blood gases.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted24 Nov 2017
- Study start4 Dec 2017
- Primary completion28 Aug 2018
- Study completion28 Aug 2018
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for AtelectasisStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind
- Who is masked
- Participant, Outcomes assessor
- Enrolment
- 30 participants (actual)
Sponsor and investigators
- Lead sponsor
- Region Västmanland
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Erland Ostberg, Region Västmanland
- Investigators
- Lennart Edmark, M.D., Ph.D., Study director, Region Västmanland
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT03351946
- Sponsor's protocol ID
- Dnr 2017/267
- Status last verified
- Sep 2018
- First submitted
- 8 Nov 2017
- Last updated
- 5 Sep 2018
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: Please email request to the study principal investigator.
Study at a glance
From the registry record, last updated by the sponsor on 5 Sep 2018. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Zero Positive End-expiratory Pressure Applied Before Emergence Preoxygenation Prevents Postoperative Atelectasis - a Randomized Controlled Trial.
- ClinicalTrials.gov ID
- NCT03351946
- Acronym / sponsor ID
- Dnr 2017/267
- Conditions
- Atelectasis, Oxygenation
- Keywords
- Atelectasis, Oxygenation, Positive end-expiratory pressure, Mechanical ventilation, General anesthesia, Computed tomography
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 30 participants (actual)
- Lead sponsor
- Region VästmanlandUniversity, hospital or other
- Study start
- 4 Dec 2017 (actual)
- Primary completion
- 28 Aug 2018 (actual)
- Study completion
- 28 Aug 2018 (actual)
- First posted
- 24 Nov 2017 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
A study on healthy patients undergoing anesthesia for non-abdominal surgery - evaluation of positive end-expiratory pressure versus zero positive end-expiratory pressure on the amount of atelectasis in the early postoperative period.
Detailed description
Positive end-expiratory pressure (PEEP) is often used during mechanical ventilation to preserve end-expiratory lung volume. After emergence and extubation, this volume will diminish instantly. Some patients will have difficulties to restore functional residual capacity (FRC) during the early phase of recovery. If routine high FIO2 has been delivered together with maintained PEEP prior to extubation, several important prerequisites are established for the development of postoperative atelectasis. The investigators hypothesize that establishing zero positive end-expiratory pressure (ZEEP) immediately prior to emergence preoxygenation, will prevent gas with high oxygen concentration from entering dorso-basal areas of the lungs, and thereby prevent postoperative atelectasis formation.
This randomized controlled study will study patients undergoing non-abdominal day case surgeries under general anesthesia. The patients in the two study groups will receive mechanical ventilation with identical settings, comprising low TV, moderate PEEP, and no RM. At the end of surgery, the lungs will be examined by CT, and any atelectasis areas will be calculated. Randomization will occur after the first CT. The patients will be allocated to zero PEEP (ZEEP) or maintained PEEP during emergence preoxygenation and extubation. Importantly, the intervention group will have ZEEP established while still having low ETO2 levels, prior to any preoxygenation. The study subjects will be examined with CT no.2 approximately thirty min after extubation. Primary endpoint measure will be atelectasis area as a percentage of total lung area. Blood gases will be collected for comparison of oxygenation as a secondary outcome measure.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (participant, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| ZEEP at awakening | Active comparator | Procedure: ZEEPControlled ventilation with tidal volume of 7 mL/kg of ideal body weight and respiratory frequency 10. Fresh gas flow is set to 1 litre/min with an oxygen mixture of 40%, aiming for an inspired oxygen fraction (FiO2) of 30-35%. Positive end-expiratory pressure (PEEP) is set to 7 or 9 cm H20 (9 if BMI≥25) until start of emergence preoxygenation. Unless the patient´s SpO2 falls below 90%, the FiO2 remains unchanged throughout the procedure. First CT scan after completion of surgery, before emergence. After the first CT scan and immediately before start of emergence preoxygenation, this group will have the PEEP exchanged for zero PEEP (ZEEP). ZEEP will remain until the study subjects are extubated. Second CT scan approx. 30 min after extubation. |
| PEEP at awakening | Active comparator | Procedure: PEEPControlled ventilation with tidal volume of 7 mL/kg of ideal body weight and respiratory frequency 10. Fresh gas flow is set to 1 litre/min with an oxygen mixture of 40%, aiming for an inspired oxygen fraction (FiO2) of 30-35%. Positive end-expiratory pressure (PEEP) is set to 7 or 9 cm H20 (9 if BMI≥25) even after start of emergence preoxygenation. Unless the patient´s SpO2 falls below 90%, the FiO2 remains unchanged throughout the procedure. First CT scan after completion of surgery, before emergence. After the first CT scan, this group will have PEEP remained until the study subjects are extubated. Second CT scan approx. 30 min after extubation. |
Who may qualify
- Ages
- 40 to 75 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (2 listed)
- American Society of Anesthesiology (ASA) class I-II
- Non-abdominal day case surgery under general anesthesia
Key exclusion criteria (9 listed)
- Body mass index (BMI) ≥30 kg/m2
- Arterial oxygen saturation (SpO2) breathing air <95 %
- Chronic Obstructive Pulmonary Disease (COPD) or symptomatic asthma
- Symptomatic congestive heart failure
- Ischemic heart disease
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| ZEEPAlso: Device: Ventilatory setting ZEEPZero positive end-expiratory pressure (ZEEP) during emergence preoxygenation and awakening. | Procedure or surgery | ZEEP at awakening |
| PEEPAlso: Device: Ventilatory setting PEEPPositive end-expiratory pressure remains during emergence preoxygenation and awakening and until the study subject is extubated. | Procedure or surgery | PEEP at awakening |
Primary outcome
Change in atelectasis area
Time frame: Within 3 hours from induction of anesthesia. First CT after surgery, before emergence. Second CT approx 25 min after extubation. Study complete after that, no further CT.
Atelectasis area as studied by computed tomography.
1 secondary outcome
Change in oxygenation
Time frame: Within 3 hours from induction of anesthesia. First blood gas after surgery, before emergence. Second approx 25 min after extubation. Study complete after that, no further blood gases.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 5 Sep 2018.
- Individual participant dataSharing planned: Yes. Please email request to the study principal investigator.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Lennart Edmark, M.D., Ph.D. study director
Region Västmanland
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing ZEEP and PEEP in people with Atelectasis and Oxygenation, run by Region Västmanland at 1 site in Sweden.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 2 inclusion and 9 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 5 Sep 2018. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Sweden. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in atelectasis area (time frame: Within 3 hours from induction of anesthesia. First CT after surgery, before emergence. Second CT approx 25 min after extubation. Study complete after that, no further CT.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 5 Sep 2018.