Ignite Creation Date:
2025-12-24 @ 9:44 PM
Ignite Modification Date:
2026-01-01 @ 3:37 PM
Study NCT ID:
NCT06736132
Status:
ACTIVE_NOT_RECRUITING
Last Update Posted:
2025-06-27
First Post:
2024-12-09
Is NOT Gene Therapy:
True
Has Adverse Events:
False
Brief Title:
Comparison of Different Oxygen Flow Rates During Preoxygenation Using High-Flow Nasal Oxygen
Sponsor:
Organization:
Raw JSON
{'hasResults': False, 'derivedSection': {'miscInfoModule': {'versionHolder': '2025-12-24'}}, 'protocolSection': {'designModule': {'phases': ['NA'], 'studyType': 'INTERVENTIONAL', 'designInfo': {'allocation': 'RANDOMIZED', 'maskingInfo': {'masking': 'DOUBLE', 'whoMasked': ['PARTICIPANT', 'CARE_PROVIDER']}, 'primaryPurpose': 'TREATMENT', 'interventionModel': 'PARALLEL', 'interventionModelDescription': 'Randomised controlled trial'}, 'enrollmentInfo': {'type': 'ESTIMATED', 'count': 75}}, 'statusModule': {'overallStatus': 'ACTIVE_NOT_RECRUITING', 'startDateStruct': {'date': '2025-01-13', 'type': 'ACTUAL'}, 'expandedAccessInfo': {'hasExpandedAccess': False}, 'statusVerifiedDate': '2024-12', 'completionDateStruct': {'date': '2026-12', 'type': 'ESTIMATED'}, 'lastUpdateSubmitDate': '2025-06-23', 'studyFirstSubmitDate': '2024-12-09', 'studyFirstSubmitQcDate': '2024-12-12', 'lastUpdatePostDateStruct': {'date': '2025-06-27', 'type': 'ACTUAL'}, 'studyFirstPostDateStruct': {'date': '2024-12-16', 'type': 'ACTUAL'}, 'primaryCompletionDateStruct': {'date': '2026-06', 'type': 'ESTIMATED'}}, 'outcomesModule': {'otherOutcomes': [{'measure': 'Differences in end-tidal and arterial carbon dioxide levels', 'timeFrame': 'From start of apnoea until end of apnoea (approximately 5 to 10 minutes)', 'description': 'Exploratory outcome. Describe the differences in end-tidal and arterial carbon dioxide levels immediately following termination of apnoea.'}, {'measure': 'Rate of arterial carbon dioxide increase during apnoea', 'timeFrame': 'From start of apnoea until end of apnoea (approximately 5 to 10 minutes)', 'description': 'Exploratory outcome. We will investigate the rate of increase in arterial carbon dioxide levels during the apnoeic period.'}], 'primaryOutcomes': [{'measure': 'Safe apnoea time', 'timeFrame': 'From start of apnoea after anaesthesia induction until peripheral oxygen saturation drops to 93%. This time fram will probably be between 5 and 15 minutes.', 'description': 'Comparison of the time from start of apnoea until reaching a SpO2 = 93% between the different flow rates'}], 'secondaryOutcomes': [{'measure': 'Tolerance of 360 seconds of apnoea', 'timeFrame': 'From apnoea start until 5 minutes of apnoea', 'description': 'Comparison between the three groups of the proportion of patients tolerating 360 seconds of apnoea'}, {'measure': 'Arterial oxygen levels during preoxygenation', 'timeFrame': 'From start of preoxygenation until end of preoxygenation (approximately 3 to 4 minutes)', 'description': 'Comparison between the groups in PaO2 at 1 minute and 2 minutes of preoxygenation and at the start of apnoea'}, {'measure': 'Discomfort assessment', 'timeFrame': 'From start of preoxygenation until the end of preoxygenation, this time fram will be three minutes.', 'description': 'Comparision between the groups in the level of discomfort during preoxygenation. Discomfort will be assessed on a scale from 1 to 10 (0 = no discomfort, 10 = maximal discomfort)'}, {'measure': 'Lung impedance changes', 'timeFrame': 'From start of preoxygenation until end of apnoea (approximately 5 to 15 minutes)', 'description': 'Lung impedance measurement will be conducted before preoxygenation (baseline) after three minutes of pre-oxygenation and at the end of apnoea. Comparisons of these values, at the different time points, will be conducted between the three groups.'}]}, 'oversightModule': {'isUsExport': False, 'oversightHasDmc': False, 'isFdaRegulatedDrug': False, 'isFdaRegulatedDevice': False}, 'conditionsModule': {'keywords': ['Preoxygenation', 'High-flow nasal oxygen', 'Anaesthesia induction'], 'conditions': ['Airway Anesthesia', 'Preoxygenation', 'High Flow Nasal Canula']}, 'referencesModule': {'references': [{'pmid': '41419379', 'type': 'DERIVED', 'citation': 'Sjoblom A, Hoffman F, Hedberg M, Forsberg IM, Jonsson Fagerlund M. Preoxygenation with high-flow nasal oxygen at various flow rates in elective surgical patients: a prospective, randomised, single-blind clinical trial. Br J Anaesth. 2025 Dec 18:S0007-0912(25)00816-5. doi: 10.1016/j.bja.2025.11.017. Online ahead of print.'}]}, 'descriptionModule': {'briefSummary': "High-flow nasal oxygen (HFNO) has been used for many years to help people with breathing difficulties in the intensive care and after surgery. More recently, it has become a helpful tool during induction of anaesthesia to prevent oxygen levels from dropping when managing the airway. HFNO is particularly effective at delivering oxygen even when a patient is not breathing (apnoea), making it useful during surgeries on the voice box (larynx) because it eliminates the need for a breathing tube, giving surgeons a clear view.\n\nHFNO is now also being used to prepare patients for anaesthesia (preoxygenation). Research shows that it works just as well as traditional tight-fitting oxygen masks while offering added benefits like better comfort for patients, easier handling for anaesthetists, and a smooth transition to oxygen delivery during apnoea.\n\nOne reason HFNO is effective is that it creates a mild pressure in the lungs, called positive end-expiratory pressure (PEEP), which improves oxygen storage in the lungs. This pressure depends on the flow rate of oxygen and is higher when the patient keeps their mouth closed. For every increase of 10 liters per minute in flow rate, HFNO generates 1 cmH2O of PEEP. This pressure helps increase the lung's capacity to hold oxygen, making the process of preoxygenation more efficient.\n\nMost studies on HFNO for preoxygenation have used flow rates of up to 60 liters per minute. However, we don't yet know if higher flow rates could further improve preoxygenation or extend the time patients can safely go without breathing.", 'detailedDescription': 'High-flow nasal oxygen (HFNO) has long been employed to address respiratory distress in both the intensive care unit and post-anaesthesia unit. Over the past decade, HFNO has emerged as a valuable tool for preventing oxygen desaturation during airway management in the operating theatre. Notably, HFNO demonstrates effectiveness in oxygenating patients during extended periods of apnoea, providing a reliable method for apnoeic oxygenation. This technique serves as an alternative to mechanical ventilation in laryngeal surgical procedures, offering potential advantages such as a clear operating field for surgeons without the interference of a tracheal tube.\n\nMore recently, HFNO has found application in preoxygenation before anaesthesia induction. Studies indicate that the preoxygenation efficacy of HFNO is comparable to that of a standard tight-fitting facemask, with added benefits including enhanced patient comfort, improved ease of use as assessed by anaesthetists, and the potential for a seamless transition to apnoeic oxygenation.\n\nOne of the suggested mechanisms contributing to the favourable outcomes observed with HFNO in managing patients with respiratory distress is a flow-dependent positive end-expiratory pressure (PEEP) effect. When patients breathe with a closed mouth, HFNO appears to generate a PEEP effect of 1 cmH2O for every 10 l.min-1 of flow. Prior data has demonstrated that an elevated PEEP leads to a greater functional residual capacity (FRC) and improved preoxygenation effectiveness.\n\nPrevious studies investigating HFNO for preoxygenation have used flow rates ≤ 60 l.min-1. Consequently, the impact of higher flow rates on preoxygenation effectiveness and the extension of safe apnoea time remains uncertain.\n\nIn this randomised prospective study, we aim to investigate the effectiveness of preoxygenation from HFNO using different flow rates. Seventy-five patients (25 per group) scheduled for elective surgery at the Karolinska University Hospital, will be recruited. After a signed consent, the subject will be enrolled and randomised to preoxygenation using HFNO at flow rates of 45 l/min, 70 l/min or 95 l/min.\n\nRoutine perioperative monitoring, such as peripheral oxygen saturation (SpO2) and non-invasive blood pressure will be performed. Preoperatively, an arterial catheter will be inserted. An arterial blood gas will be attained before preoxygenation for base line data regarding PaCO2, PaO2 and pH.\n\nTo enable lung impedance measurement, all subjects will be applied an appropriately sized circumferential 16-electrode belt around the torso between the fourth and sixth intercostal spaces.\n\nPatients will be positioned supine with the head elevated at 15 degrees. All groups will undergo preoxygenation using HFNO with the flow rate determined by the randomisation. All groups will be preoxygenated for 3 minutes using 100% oxygen and closed-mouth breathing. Immediately prior to anaesthesia induction, patients will evaluate the level of discomfort of preoxygenation. Thereafter, anaesthesia is induced.\n\nPreoxygenation will be administered to all patients until the onset of apnoea, at which point oxygen delivery via HFNO will be immediately discontinued. The patient will then undergo intubation, with apnoea maintained until their oxygen saturation drops to 93%. Once this threshold is reached, mechanical ventilation with 100% oxygen will be initiated.'}, 'eligibilityModule': {'sex': 'ALL', 'stdAges': ['ADULT', 'OLDER_ADULT'], 'maximumAge': '84 Years', 'minimumAge': '18 Years', 'healthyVolunteers': True, 'eligibilityCriteria': 'Inclusion Criteria:\n\n* Adult, 18-84 years old\n* ASA 1-3\n* BMI \\< 35\n* Planned for elective surgery\n\nExclusion Criteria:\n\n* Cardiac disease (ischemic heart disease, heart failure (NYHA ≥2), ongoing arrhythmias, pulmonary hypertension)\n* Severe asthma, moderate to severe COPD\n* Pregnancy\n* Smokers or former smoker last finished 1 year before inclusion\n* Baseline oxygen saturation \\< 95%\n* Nasal obstruction\n* Known or anticipated difficult airway\n* Patients with electrical active implants where lung impedance analysis is contraindicated\n* Not capable of understanding study information and signing a written consent'}, 'identificationModule': {'nctId': 'NCT06736132', 'acronym': 'PREFLOW2', 'briefTitle': 'Comparison of Different Oxygen Flow Rates During Preoxygenation Using High-Flow Nasal Oxygen', 'organization': {'class': 'OTHER_GOV', 'fullName': 'Region Stockholm'}, 'officialTitle': 'Comparison of Different Oxygen Flow Rates During Preoxygenation Using High-Flow Nasal Oxygen', 'orgStudyIdInfo': {'id': 'DNR: 2024-04565-01'}, 'secondaryIdInfos': [{'id': 'SLS-1000363 & SLS-999871', 'type': 'OTHER_GRANT', 'domain': 'Läkaresällskapet'}]}, 'armsInterventionsModule': {'armGroups': [{'type': 'ACTIVE_COMPARATOR', 'label': 'High-flow nasal oxygen, flow rate 45 l/min', 'description': 'Preoxygenation using high-flow nasal oxygen with a flow rate of 45 l/min', 'interventionNames': ['Device: High-flow nasal oxygen']}, {'type': 'EXPERIMENTAL', 'label': 'High-flow nasal oxygen, flow rate 70 l/min', 'description': 'Preoxygenation using high-flow nasal oxygen with a flow rate of 70 l/min', 'interventionNames': ['Device: High-flow nasal oxygen']}, {'type': 'EXPERIMENTAL', 'label': 'High-flow nasal oxygen, flow rate 95 l/min', 'description': 'Preoxygenation using high-flow nasal oxygen with a flow rate of 95 l/min', 'interventionNames': ['Device: High-flow nasal oxygen']}], 'interventions': [{'name': 'High-flow nasal oxygen', 'type': 'DEVICE', 'description': 'In this study, we will use high-flow nasal oxygen for preoxygenation in patients undergoing elective anaesthesia. Preoxygenation with high-flow nasal oxygen is most often performed at flow rates of \\<50 l/min. In this study, patients will be randomised to preoxygenation using high-flow nasal oxygen and flow rates of 45 l/min, 70 l/min or 95 /min.', 'armGroupLabels': ['High-flow nasal oxygen, flow rate 45 l/min', 'High-flow nasal oxygen, flow rate 70 l/min', 'High-flow nasal oxygen, flow rate 95 l/min']}]}, 'contactsLocationsModule': {'locations': [{'zip': '17176', 'city': 'Solna', 'country': 'Sweden', 'facility': 'Karolinska University Hospital', 'geoPoint': {'lat': 59.36004, 'lon': 18.00086}}]}, 'ipdSharingStatementModule': {'ipdSharing': 'NO', 'description': 'The data that support the findings of this study are available on request from the corresponding author. The data are not publicly available because they contain information that could compromise the privacy of research participants.'}, 'sponsorCollaboratorsModule': {'leadSponsor': {'name': 'Region Stockholm', 'class': 'OTHER_GOV'}, 'collaborators': [{'name': 'Karolinska Institutet', 'class': 'OTHER'}], 'responsibleParty': {'type': 'PRINCIPAL_INVESTIGATOR', 'investigatorTitle': 'Principal Investigator', 'investigatorFullName': 'Albin Sjöblom', 'investigatorAffiliation': 'Region Stockholm'}}}}