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Obesity, MorbidEPO2-ANCT02590406

EPO2-A: Evaluation of Pre-Oxygenation in Morbid Obesity: Effect of Position and Positive Pressure Ventilation

A study testing Beach chair (BC) and ZEEP and Reverse Trendelenburg and NIPPV in people with Obesity, Morbid, run by Laval University at 1 site in Canada.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The risk of complication associated with airway in obese patient is important. The result of pre-oxygenation gives the clinician a prolonged non-hypoxic apnea time. The relation between FRC and non-hypoxic apnea time has been correlated. Read more about this study

Who is it for?
Ages 21 to 70 years
Conditions the study is for
Obesity, Morbid
What is being tested?
Beach chair (BC) and ZEEP and Reverse Trendelenburg and NIPPV
Type of treatment
Surgery or procedure
Could I receive a placebo?
No, everyone receives an active treatment
How many people
50 participants
Where
1 siteCanada
Study dates
Sep 2015to Mar 2016
Phase
Interventional
Are there results?
Yes, posted in the registrySummary in the doctors' view

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 21 to 70 years
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • BMI > 40
  • Abdominal obesity : waist circumference: > 115 for the women waist circumference > 130 for the men

Who cannot join

  • Facial hair
  • Cranio-facial abnormality
  • Asthma (continuous treatment)
  • COPD (FEV1 < 80%)
  • Severe cardiovascular disease (NYHA > 3)
  • Pregnancy
Show all 9Show fewer
  • Tobacco use
  • Know or suspected difficulty with intubation
  • Severe GERD or risk of aspiration

Trial locations and contacts

1 site in 1 country.

Canada1 site
  • Institut universitaire de cardiologie et de pneumologie de Québec

    Québec, Quebec, G1V4G5

Other trials in Canada

About this study

Official title: EPO2-A: Evaluation of Different Pre-Oxygenation Condition in Morbid Obesity: Effect of Position and Positive Pressure Ventilation During General Anesthesia Induction

The risk of complication associated with airway in obese patient is important. The result of pre-oxygenation gives the clinician a prolonged non-hypoxic apnea time. The relation between FRC and non-hypoxic apnea time has been correlated. However, the best condition to accomplish the pre-oxygenation in morbidly obese patient has yet to be described in the medical literature. A study previously done in our hospital (EPO2-PV) compared the effect of different positions and ventilation modes on the FRC in the laboratory. A significant difference has been established on the FRC between the inverse Trendelenburg position with positive pressure ventilation and the head up ("beach-chair") position without positive pressure. The current study, EPO2-A is designed to compared the two positions and ventilation modes during the induction of general anesthesia on morbidly obese and correlate the difference in FRC to difference in apnea time.

Read the detailed description

Obesity prevalence in the population is increasing. Thus a growing number of obese patient need surgical interventions. These patients have a four time higher risk of suffering of serious complication in relation with their airway management compare with non-obese patients. This is explained by an increased incidence of difficulty with the ventilation and intubation of the obese. The time available for the clinician to manage the airway is define by the non hypoxic apnea time. This laps of time is dependent of the oxygen stocks of the patient, which are dependent of the functional residual capacity (FRC) and his oxygen consumption. For a non-obese patient, a normal pre-oxygenation of three minutes at 100% of oxygen allows a non hypoxic apnea time (oxygen saturation > 90%) of 8,9 minutes. However, for the morbidly obese, this time is cut to less than three minutes.

The major goal of the pre-oxygenation is to increase the alveolar partial pressure of oxygen available in the end-expiratory pulmonary volume. This can be done by replacing the nitrogen in the alveolus by oxygen and by increasing the pulmonary stocks, the FRC. It has been demonstrated that the FRC after the induction of anesthesia is cut by half for the obese. This reduction is explained by a diminished thoracic compliance and an increase of the dependent lung regions' atelectasis because of a more cephalic position of the diaphragm.

Various pre-oxygenation methods have been described to prolong the non hypoxic apnea time in the obese population. Some proposed pre-oxygenation strategies with the patient in the head up position (beach chair). It is a position derived from the ramped position described as the best to visualized the obese patients' glottis. Others proposed pre-oxygenation strategies with positive pressure ventilation, but only the supine position has been studied concomitantly.

Individually, these techniques of pre-oxygenation are superior to the combination of supine position and no positive pressure. Indeed, studies demonstrated that the beach chair position (derived from the ramped position) or the positive pressure pre-oxygenation in supine position diminished the time needed to obtain a satisfactory pre-oxygenation (End-expiratory oxygen fraction >0,9) and a longer non hypoxic apnea time. Sill, these strategies have never been combined in the same protocol.

The beach chair position without positive pressure ventilation has become the standard of care because it is the position that allows the best glottis view. Though, it has been shown by Boyce and coll. that the reverse Trendelenburg position, and not the beach chair, increased the non hypoxic apnea time, the recuperation time and the minimal saturation obtained compared to the supine position. We think that there is an advantage to use the reverse Trendelenburg position to optimize the non hypoxic apnea time. Indeed, our hypothesis is that there will be less pressure on the diaphragm in comparison with the beach char position.

A studied realized by our group (EPO2-PV) evaluated the effect of three positions (Reverse Trendelenburg, beach chair and supine) and two ventilation strategies (spontaneous ventilation with or without positive pressure) on morbidly obese FRC in laboratory. The results showed a statistically significant difference on the FRC after a pre-oxygenation with positive pressure compared with the pre-oxygenation without positive pressure, and this regardless of the position. Moreover, for both ventilation strategies, results demonstrated a statistically significant superiority between the FRC obtained after pre-oxygenation in reverse Trendelenburg compared with the beach chair and the supine position. No improvement has been shown with the beach chair position.

Thereby, the current study will try to correlate the FRC results obtained in laboratory in actual non hypoxic apnea time in the operating room. This research design tries to compare, in patient receiving general anesthesia for bariatric surgeries, the effect of the pre-oxygenation with positive pressure and the reverse Trendelenburg position, on the non hypoxic apnea time in comparison with the actual standard of care, beach chair position without positive pressure ventilation.

Conditions
Obesity, Morbid
Being tested
Beach chair (BC) and ZEEP, Reverse Trendelenburg and NIPPV
Keywords
Morbid Obesity, Bariatric Surgery, Pre-Oxygenation, Anesthesia Induction, Positive pressure ventilation, Non hypoxic apnea time, Positive-Pressure Respiration, Anesthesia, General
Medical subject headings
Obesity, Morbid

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Beach chair (BC) and ZEEPProcedure or surgery

    Table Position: Beach chair, Inclination of the upper part of the table at 25 degrees, breaking at the patient's hips ZEEP: 3 minutes pre-oxygenation with tidal volumes, FiO2 100%, mouth piece used as a ventilatory interface

  • Reverse Trendelenburg and NIPPVProcedure or surgery

    Table Position: Reverse Trendelenburg, Inclination of the whole table at 25 degrees from an horizontal plane, head up.

    NIPPV: 3 minutes of pre-oxygenation with 8 cm H2O positive pressure and 10 cm H2O PEEP. Trigger set at 1,5 L/min, mouth piece is used as a ventilatory interface

Study groups in NCT02590406
Study groupRoleWhat they receive
Beach chair (BC) and ZEEPActive comparatorTable Position: Beach chair, Inclination of the upper part of the table at 25 degrees, breaking at the patient's hips ZEEP: 3 minutes pre-oxygenation with tidal volumes, FiO2 100%, mouth piece used as a ventilatory interface
Receives: Procedure: Beach chair (BC) and ZEEP
Reverse Trendelenburg and NIPPVExperimentalTable Position: Reverse Trendelenburg, Inclination of the whole table at 25 degrees from an horizontal plane, head up. NIPPV: 3 minutes of pre-oxygenation with 8 cm H2O positive pressure and 10 cm H2O PEEP. Trigger set at 1,5 L/min, mouth piece is used as a ventilatory interface
Receives: Procedure: Reverse Trendelenburg and NIPPV

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Non Hypoxic Apnea Time

    Change of Non-hypoxic apnea time in obese patient during a General Anesthesia induction, as a result of different pre-oxygenation position and ventilation mode; 1-Beach Chair and No positive pressure ventilation, 2-Reverse Trendelenburg and positive pressure ventilation and PEEP. End of measure time frame is 5 minutes after intubation

    Measured: After a 3 minutes pre-oxygenation period

Secondary outcomes (5)
  1. Time to Expired Oxygen Fraction > 0,9

    Evaluation of time needed to obtain an expired fraction of oxygen of > 0,9 in the two groups during the pre-oxygenation

    Measured: During the pre-oxygenation period

  2. Maximum Expired Fraction of Oxygen Obtained

    Evaluation of the maximum expired oxygen fraction obtained in the two groups

    Measured: After 3 minutes of pre-oxygenation

  3. Minimum Arterial Saturation of Oxygen Obtained

    Evaluation of the minimal saturation obtained after the resumption of the ventilation

    Measured: After the end of the Non-hypoxic apnea time

  4. Time to 97% Saturation

    Measured: Evaluation of the time needed to the beginning of the ventilation to the moment where the saturation is 97%

  5. Hemodynamic Changes

    Evaluation of the changes in vital signs during and after the pre-oxygenation phase in the two combinations of position and ventilation mode

    Measured: From the beginning of the pre-oxygenation to the end of the protocol

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted29 Oct 2015 (estimated)
  2. Study startSep 2015
  3. Primary completionJan 2016
  4. Study completionMar 2016

Resources

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
Single blind
Who is masked
Participant
Enrolment
50 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT02590406
Sponsor's protocol ID
IUCPQ 21211
Acronym
EPO2-A
Status last verified
Mar 2020
First submitted
6 Oct 2015
Last updated
25 Mar 2020
Data monitoring committee
No

Publications

  • Cook TM, Woodall N, Frerk C; Fourth National Audit Project. Major complications of airway management in the UK: results of the Fourth National Audit Project of the Royal College of Anaesthetists and the Difficult Airway Society. Part 1: anaesthesia. Br J Anaesth. 2011 May;106(5):617-31. doi: 10.1093/bja/aer058. Epub 2011 Mar 29.

    PubMed 21447488
  • Juvin P, Lavaut E, Dupont H, Lefevre P, Demetriou M, Dumoulin JL, Desmonts JM. Difficult tracheal intubation is more common in obese than in lean patients. Anesth Analg. 2003 Aug;97(2):595-600. doi: 10.1213/01.ANE.0000072547.75928.B0.

    PubMed 12873960
  • Langeron O, Masso E, Huraux C, Guggiari M, Bianchi A, Coriat P, Riou B. Prediction of difficult mask ventilation. Anesthesiology. 2000 May;92(5):1229-36. doi: 10.1097/00000542-200005000-00009.

    PubMed 10781266
  • Tanoubi I, Drolet P, Donati F. Optimizing preoxygenation in adults. Can J Anaesth. 2009 Jun;56(6):449-66. doi: 10.1007/s12630-009-9084-z. Epub 2009 Apr 28.

    PubMed 19399574
  • Gambee AM, Hertzka RE, Fisher DM. Preoxygenation techniques: comparison of three minutes and four breaths. Anesth Analg. 1987 May;66(5):468-70. No abstract available.

    PubMed 3578856
  • Jense HG, Dubin SA, Silverstein PI, O'Leary-Escolas U. Effect of obesity on safe duration of apnea in anesthetized humans. Anesth Analg. 1991 Jan;72(1):89-93. doi: 10.1213/00000539-199101000-00016.

    PubMed 1984382
  • Damia G, Mascheroni D, Croci M, Tarenzi L. Perioperative changes in functional residual capacity in morbidly obese patients. Br J Anaesth. 1988 Apr;60(5):574-8. doi: 10.1093/bja/60.5.574.

    PubMed 3377932
  • Pelosi P, Croci M, Ravagnan I, Tredici S, Pedoto A, Lissoni A, Gattinoni L. The effects of body mass on lung volumes, respiratory mechanics, and gas exchange during general anesthesia. Anesth Analg. 1998 Sep;87(3):654-60. doi: 10.1097/00000539-199809000-00031.

    PubMed 9728848
  • Altermatt FR, Munoz HR, Delfino AE, Cortinez LI. Pre-oxygenation in the obese patient: effects of position on tolerance to apnoea. Br J Anaesth. 2005 Nov;95(5):706-9. doi: 10.1093/bja/aei231. Epub 2005 Sep 2.

    PubMed 16143575
  • Boyce JR, Ness T, Castroman P, Gleysteen JJ. A preliminary study of the optimal anesthesia positioning for the morbidly obese patient. Obes Surg. 2003 Feb;13(1):4-9. doi: 10.1381/096089203321136511.

    PubMed 12630606
  • Lane S, Saunders D, Schofield A, Padmanabhan R, Hildreth A, Laws D. A prospective, randomised controlled trial comparing the efficacy of pre-oxygenation in the 20 degrees head-up vs supine position. Anaesthesia. 2005 Nov;60(11):1064-7. doi: 10.1111/j.1365-2044.2005.04374.x.

    PubMed 16229689
  • Collins JS, Lemmens HJ, Brodsky JB, Brock-Utne JG, Levitan RM. Laryngoscopy and morbid obesity: a comparison of the "sniff" and "ramped" positions. Obes Surg. 2004 Oct;14(9):1171-5. doi: 10.1381/0960892042386869.

    PubMed 15527629
  • Levitan RM, Mechem CC, Ochroch EA, Shofer FS, Hollander JE. Head-elevated laryngoscopy position: improving laryngeal exposure during laryngoscopy by increasing head elevation. Ann Emerg Med. 2003 Mar;41(3):322-30. doi: 10.1067/mem.2003.87.

    PubMed 12605198
  • Coussa M, Proietti S, Schnyder P, Frascarolo P, Suter M, Spahn DR, Magnusson L. Prevention of atelectasis formation during the induction of general anesthesia in morbidly obese patients. Anesth Analg. 2004 May;98(5):1491-5, table of contents. doi: 10.1213/01.ane.0000111743.61132.99.

    PubMed 15105237
  • Cressey DM, Berthoud MC, Reilly CS. Effectiveness of continuous positive airway pressure to enhance pre-oxygenation in morbidly obese women. Anaesthesia. 2001 Jul;56(7):680-4. doi: 10.1046/j.1365-2044.2001.01374-3.x.

    PubMed 11437771

Questions about this trial

What is this clinical trial studying?

A study testing Beach chair (BC) and ZEEP and Reverse Trendelenburg and NIPPV in people with Obesity, Morbid, run by Laval University at 1 site in Canada.

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 25 Mar 2020. 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 Canada. 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?

Yes. Results are posted in the registry (first posted 18 Mar 2020). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.

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?

Non Hypoxic Apnea Time (time frame: After a 3 minutes pre-oxygenation period). It is what the study was designed to measure, not a finding.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT02590406, which also lists 21 linked publications.

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 25 Mar 2020.

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