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Effect of HFNO on Spontaneous Ventilation in Obese Patients During Analgo-sedation for Vitrectomy

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ClinicalTrials.gov Identifier: NCT04049240
Recruitment Status : Recruiting
First Posted : August 8, 2019
Last Update Posted : August 13, 2019
Sponsor:
Collaborator:
Clinical Hospital Centre Zagreb
Information provided by (Responsible Party):
Anita Vukovic, University of Split, School of Medicine

Brief Summary:

Patients suffering from pathology of posterior eye chamber such as diabetic retinopathy, retinal detachment, traumatic eye injury, retained lens fragments, macular hole, pucker, dislocated intraocular lens after cataract surgery or vitreomacular traction are often subjected to pars plana vitrectomy (PPV). PPV is minimally invasive endo-microscopic operation usually performed in topical anesthesia combined with sub-Tenon or retrobulbar block done by surgeon, supplemented by intravenous analgo-sedation given by anesthesiologist.

Continuous infusion and dose adjustment of intravenous anesthetics applied should procure moderate sedation and preservation of patients' spontaneous ventilation. However, despite carefully applied anesthetics and standard low-flow nasal oxygenation (LFNO) (5 L/min O2 via nasal catheter), inadequate spontaneous breathing can occur leading to low blood oxygen level (hypoxia). Obese patients are susceptible to hypoxia and hypercapnia (high CO2 blood level) during analgo-sedation. Respiratory instability of obese patients is often associated to their subsequent circulatory instability (heart rate and blood pressure disorders).

On the other hand, high-flow nasal oxygenation (HFNO) is usually used during anesthesia induction when difficult maintenance of airway patency is expected, in intensive care units during weaning patients from mechanical respirator and in postanesthesia care units during awakening from anesthesia. It can deliver 20 to 70 L/min, up to 100% inspiratory fraction of O2 (FiO2) to patient. High oxygen/air flow produces 3-7 cmH2O of continuous pressure in patients' upper airways therefore providing better oxygenation. Oxygen/air mixture delivered by HFNO is humidified and heated, thus more comfortable to patient than dry and cold LFNO.

Aim of this study is to compare effect of HFNO to LFNO during intravenously applied standardized analgo-sedation given for PPV in obese adult patients.

Investigators hypothesize that obese patients, whose breathing pattern is preserved, receiving HFNO vs. LFNO during standardized analgo-sedation for PPV will be more respiratory and circulatory stable, preserving normal blood O2 and CO2 level, breathing pattern, heart rate and blood pressure.


Condition or disease Intervention/treatment Phase
Sedation Complication Obesity Hypoxic Respiratory Failure Airway Obstruction, Nasal Respiratory Insufficiency Apnea Device: Device: low-flow nasal oxygenation (LFNO) 18<BMI<30 kg/m2 Device: Device: low-flow nasal oxygenation (LFNO) 30≤BMI<35 kg/m2 Device: Device: low-flow nasal oxygenation (LFNO) BMI≥35 kg/m2 Device: Device: High-flow nasal oxygenation (HFNO) 18<BMI<30 kg/m2 Device: Device: High-flow nasal oxygenation (HFNO) 30≤BMI<35 kg/m2 Device: Device: High-flow nasal oxygenation (HFNO) BMI≥35 kg/m2 Not Applicable

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 126 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Intervention Model Description:

Investigators plan to conduct prospective, parallel group, randomized controlled clinical trial.

In total, 126 participants will be included in this trial. These participants are patients scheduled for outpatient analgo-sedation for vitrectomy.

Masking: Double (Investigator, Outcomes Assessor)
Masking Description: Anesthesiologist who interviews and examines patients scheduled for PPV under analgo-sedation will enroll eligible participants and offer procedure explanation with possibility to sign uniformed written consent. Unique personal hospital admission number (UPHAN) will be assigned to all eligible participants. Participants will be randomized to control or intervention group by using random numbers generator. Anesthesiologist who implements anesthesia will receive nontransparent envelope with assigned intervention provided by independent investigator and will not decide which participant will receive LFNO or HFNO. However, attending anesthesiologist and participants will unavoidably be aware of type of oxygenation applied. Collected data are objective measures. Investigator who collects data after procedure will be unaware of study protocol and will enter data to formatted database. Participants' data will be noted under UPHAN. Outcome assessors will be unaware of intervention applied.
Primary Purpose: Treatment
Official Title: Effect of High-flow vs. Low-flow Nasal Oxygenation on Spontaneous Ventilation in Obese Adult Patients During Analgo-sedation for Vitrectomy, Randomized Controlled Trial
Actual Study Start Date : August 1, 2019
Estimated Primary Completion Date : February 1, 2020
Estimated Study Completion Date : August 1, 2020

Arm Intervention/treatment
Active Comparator: Active Comparator: 18<BMI<30 - LFNO
Low-flow nasal oxygenation (LFNO) O2 flow 5L/min, FiO2 40%
Device: Device: low-flow nasal oxygenation (LFNO) 18<BMI<30 kg/m2
Active comparator LFNO: O2 flow 5 L/min, FiO2 40%

Active Comparator: Active Comparator: 30≤BMI<35 kg/m2 - LFNO
Low-flow nasal oxygenation (LFNO) O2 flow 5L/min, FiO2 40%
Device: Device: low-flow nasal oxygenation (LFNO) 30≤BMI<35 kg/m2
Active comparator LFNO: O2 flow 5 L/min, FiO2 40%

Active Comparator: Active Comparator: BMI≥35 kg/m2 - LFNO
Low-flow nasal oxygenation (LFNO) O2 flow 5L/min, FiO2 40%
Device: Device: low-flow nasal oxygenation (LFNO) BMI≥35 kg/m2
Active comparator LFNO: O2 flow 5 L/min, FiO2 40%

Active Comparator: Experimental: 18<BMI<30 kg/m2 - HFNO
High Flow nasal oxygenation (HFNO) O2 flow 40L/min, FiO2 40%
Device: Device: High-flow nasal oxygenation (HFNO) 18<BMI<30 kg/m2
Experimental HFNO: O2 flow 40 L/min, FiO2 40%

Active Comparator: Experimental: 30≤BMI<35 kg/m2 - HFNO
High Flow nasal oxygenation (HFNO) O2 flow 40L/min, FiO2 40%
Device: Device: High-flow nasal oxygenation (HFNO) 30≤BMI<35 kg/m2
Experimental HFNO: O2 flow 40 L/min, FiO2 40%

Active Comparator: Experimental: BMI≥35 kg/m2 - HFNO
High Flow nasal oxygenation (HFNO) O2 flow 40L/min, FiO2 40%
Device: Device: High-flow nasal oxygenation (HFNO) BMI≥35 kg/m2
Experimental HFNO: O2 flow 40 L/min, FiO2 40%




Primary Outcome Measures :
  1. Maintaining oxygenation above the level of hypoxemia. Measure: peripheral blood saturation (SpO2) before application of LFNO or HFNO. [ Time Frame: Time 0=before oxygenation ]
    Normal range >92% Acceptable deflection from normal values of peripheral blood saturation (SpO2) significant for hypoxemia is ≤92%, while all values above will be considered normal. SpO2 will be observed during procedure so that we can confirm or exclude differences connected with practical application of LFNO and HFNO.

  2. Maintaining oxygenation above the level of hypoxemia. Measure: peripheral blood saturation (SpO2) 15 minutes after institution of LFNO or HFNO. [ Time Frame: Time 1=15 minutes after institution of LFNO or HFNO, ]
    Normal range >92% Acceptable deflection from normal values of peripheral blood saturation (SpO2) significant for hypoxemia is ≤92%, while all values above will be considered normal. SpO2 will be observed during procedure so that we can confirm or exclude differences connected with practical application of LFNO and HFNO.

  3. Maintaining oxygenation above the level of hypoxemia. Measure: peripheral blood saturation (SpO2) 5 minutes after discontinuing analgo-sedation and oxygenation (LFNO and HFNO). [ Time Frame: Time 2=5 minutes after discontinuing analgo-sedation and oxygenation (LFNO and HFNO). ]
    Normal range >92% Acceptable deflection from normal values of peripheral blood saturation (SpO2) significant for hypoxemia is ≤92%, while all values above will be considered normal. SpO2 will be observed during procedure so that we can confirm or exclude differences connected with practical application of LFNO and HFNO.


Secondary Outcome Measures :
  1. Maintaining of expiratory efficiency of spontaneous breathing below hypercapnia value. Measure: expiratory level of CO2 (expCO2) before oxygenation by LFNO or HFNO. [ Time Frame: Time 0=before oxygenation by LFNO or HFNO ]
    Normal range: 34 - 45 mmHg. Acceptable deflection from normal values significant for hypercapnia: expCO2 > 45 mmHg.

  2. Maintaining of expiratory efficiency of spontaneous breathing below hypercapnia value. Measure: expiratory level of CO2 (expCO2) 15 minutes after institution of LFNO or HFNO. [ Time Frame: Time 1=15 minutes after institution of LFNO or HFNO ]
    Normal range: 34 - 45 mmHg. Acceptable deflection from normal values significant for hypercapnia: expCO2 > 45 mmHg.

  3. Maintaining of expiratory efficiency of spontaneous breathing below hypercapnia value. Measure: expiratory level of CO2 (expCO2) 5 minutes after discontinuing analgo-sedation and oxygenation (LFNO or HFNO). [ Time Frame: Time 2=5 minutes after discontinuing analgo-sedation and oxygenation (LFNO or HFNO). ]
    Normal range: 34 - 45 mmHg. Acceptable deflection from normal values significant for hypercapnia: expCO2 > 45 mmHg.

  4. Maintaining of normopnoea and spontaneous ventilation: frequency of breathing Measure: frequency of breathing before oxygenation by LFNO or HFNO. [ Time Frame: Time 0=before oxygenation by LFNO or HFNO. ]
    Frequency of breathing. Normal range: 12-20 breaths per minute. Frequency of breathing (FoB) - number of breaths per minute.

  5. Maintaining of normopnoea and spontaneous ventilation: frequency of breathing Measure: frequency of breathing 15 minutes after institution of LFNO or HFNO. [ Time Frame: Time 1=15 minutes after institution of LFNO or HFNO. ]
    Frequency of breathing. Normal range: 12-20 breaths per minute. Frequency of breathing (FoB) - number of breaths per minute.

  6. Maintaining of normopnoea and spontaneous ventilation: frequency of breathing. Measure: frequency of breathing 5 minutes after discontinuing analgo-sedation and oxygenation (LFNO or HFNO). [ Time Frame: Time 2=5 minutes after discontinuing analgo-sedation and oxygenation (LFNO or HFNO). ]
    Frequency of breathing. Normal range: 12-20 breaths per minute. Frequency of breathing (FoB) - number of breaths per minute.

  7. Maintaining of normopnoea and spontaneous ventilation: frequency of bradypnoea during analgo-sedation and oxygenation by LFNO or HFNO (fBRP/min). [ Time Frame: Procedure (From the start until the end of analgo-sedation and oxygenation by LFNO or HFNO.) ]
    Frequency of breathing. Normal range: 12-20 breaths per minute. Bradypnoea will be noted when number of breaths is less then 12 breaths per minute. Normal range: up to one episode of bradypnoea during procedure. Acceptable deflection from normal range: >1 episode of bradypnoea during procedure.

  8. Maintaining of normopnoea and spontaneous ventilation: frequency of desaturation during time of analgo-sedation and oxygenation by LFNO or HFNO. [ Time Frame: Procedure (From the start until the end of analgo-sedation and oxygenation by LFNO or HFNO.) ]
    Frequency of desaturation during time of analgo-sedation: fDE, SpO2<92%. Normal range fDE = 1/60 min. Acceptable deflection from normal range: a ratio higher than 1/60 min.

  9. Maintaining of normopnoea and spontaneous ventilation: Duration of desaturation (DE/min) from the start until the end of analgo-sedation and oxygenation by LFNO or HFNO. [ Time Frame: up to 1 minute (From the start until the end of analgo-sedation and oxygenation by LFNO or HFNO.) ]
    Normal range: SpO2<92% up to one minute. Duration of desaturation longer than one minute will be considered as insufficient ventilation.

  10. Measurement of procedural parameters: duration of analgo-sedation. [ Time Frame: Procedure (From the start until the end of analgo-sedation.) ]
    Duration of analgo-sedation (min) - expected duration (minutes).

  11. Measurement of procedural parameters: duration of awakening (awaken patient). [ Time Frame: up to 5 minutes ]
    Duration of awakening (min) - expected duration up to 5 minutes (minutes).

  12. Circulatory stability: heart rate before oxygenation by LFNO or HFNO [ Time Frame: Time 0=before oxygenation by LFNO or HFNO ]
    Heart rate (HR/min): normal range 60-100/min. Acceptable deflection from normal values is <60/heartbeats/min significant for bradycardia, while all values up to 100 heartbeats per minute will be considered normal.

  13. Circulatory stability: heart rate 15 minutes after institution of LFNO or HFNO. [ Time Frame: Time 1=15 minutes after institution of LFNO or HFNO. ]
    Heart rate (HR/min): normal range 60-100/min. Acceptable deflection from normal values is <60/heartbeats/min significant for bradycardia, while all values up to 100 heartbeats per minute will be considered normal.

  14. Circulatory stability: heart rate 5 minutes after discontinuing analgo-sedation and oxygenation (LFNO or HFNO). [ Time Frame: Time 2=5 minutes after discontinuing analgo-sedation and oxygenation (LFNO or HFNO). ]
    Heart rate (HR/min): normal range 60-100/min. Acceptable deflection from normal values is <60/heartbeats/min significant for bradycardia, while all values up to 100 heartbeats per minute will be considered normal.

  15. Circulatory stability: mean arterial pressure before oxygenation by LFNO or HFNO [ Time Frame: Time 0=before oxygenation by LFNO or HFNO. ]
    Mean arterial pressure (MAP): normal range: 65 - 110/min Acceptable deflection from normal values is <65 mmHg significant for hypotension, >110 mmHg for hypertension.

  16. Circulatory stability: mean arterial pressure 15 minutes after institution of LFNO or HFNO [ Time Frame: Time 1=15 minutes after institution of LFNO or HFNO. ]
    Mean arterial pressure (MAP): normal range: 65 - 110/min Acceptable deflection from normal values is <65 mmHg significant for hypotension, >110 mmHg for hypertension.

  17. Circulatory stability: mean arterial pressure 5 minutes after discontinuing analgo-sedation and oxygenation (LFNO or HFNO). [ Time Frame: Time 2=5 minutes after discontinuing analgo-sedation and oxygenation (LFNO or HFNO). ]
    Mean arterial pressure (MAP): normal range: 65 - 110/min Acceptable deflection from normal values is <65 mmHg significant for hypotension, >110 mmHg for hypertension.



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Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


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Ages Eligible for Study:   18 Years and older   (Adult, Older Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Normal weight and obese patients (18<BMI<30 kg/m2, 30≤BMI<35 kg/m2, BMI≥35 kg/m2)
  • Moderate intravenous analgo-sedation
  • Pars plana vitrectomy

Exclusion Criteria:

  • Higher anesthesia risk patients (ASA III)
  • Conventional vitrectomy
  • Diseases of peripheral blood vessels
  • Hematological diseases
  • Psychiatric diseases
  • Sideropenic anemia
  • Patient's refusal
  • Ongoing chemotherapy or irradiation
  • Remifentanyl and Xomolix allergies

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT04049240


Contacts
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Contact: Dubravka Bartolek Hamp, Assist.prof. 911963033 ext +385 dbartolekh@gmail.com
Contact: Anita Vukovic, MD 989264821 ext +385 anita_vukovic1@yahoo.com

Locations
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Croatia
University clinical hospital centre Zagreb Recruiting
Zagreb, Croatia, 10000
Contact: Slobodan Mihaljevic, Prof.    12388-888 ext +385    predstojnik.kai@kbc-zagreb.hr   
Sponsors and Collaborators
University of Split, School of Medicine
Clinical Hospital Centre Zagreb
Additional Information:
Publications:

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Responsible Party: Anita Vukovic, MD, specialist of anesthesiology, reanimatology and intensive care, University of Split, School of Medicine
ClinicalTrials.gov Identifier: NCT04049240    
Other Study ID Numbers: 8.1-19/188-1B
First Posted: August 8, 2019    Key Record Dates
Last Update Posted: August 13, 2019
Last Verified: August 2019
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Anita Vukovic, University of Split, School of Medicine:
Noninvasive Ventilation
Obesity
Moderate sedation
Adult
High-flow nasal oxygenation
Vitrectomy
Airway management
Additional relevant MeSH terms:
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Respiratory Insufficiency
Airway Obstruction
Nasal Obstruction
Pulmonary Valve Insufficiency
Respiration Disorders
Respiratory Tract Diseases
Heart Valve Diseases
Heart Diseases
Cardiovascular Diseases
Nose Diseases
Otorhinolaryngologic Diseases