Aneurysmal Subarachnoid Hemorrhage (aSAH)
Conditions
Keywords
Aneurysmal Subarachnoid Hemorrhage (aSAH), Hypocapnia
Brief summary
Based on the clinical observation that over half of the patients in the management of aneurysmal subarachnoid hemorrhage(aSAH) present with spontaneous hyperventilation, which is significantly associated with delayed cerebral ischemia and poor neurological outcomes, this prospective pilot study is designed to investigate the safety and efficacy of normobaric facemask oxygen for hypocapnia in aSAH.
Detailed description
Spontaneous hyperventilation (SH) is highly prevalent following aneurysmal subarachnoid hemorrhage (aSAH) and is significantly associated with poor neurological outcomes.The core pathophysiological mechanism involves hypocapnia induced by hyperventilation, which triggers cerebral vasoconstriction and consequently leads to a decrease in cerebral blood flow (CBF).Although this response may transiently reduce intracranial pressure, persistent cerebral vasoconstriction markedly increases the risk of delayed cerebral ischemia (DCI) and secondary brain injury. Therefore, maintaining the arterial partial pressure of carbon dioxide (PaCO2) within the physiological range of mmHg is recommended to minimize the detrimental effects of hypocapnia. Currently, there is a lack of standardized management strategies for hypocapnia resulting from SH after aSAH. Based on physiological principles, low-flow (\<5 L/min) oxygen delivery via a facemask may effectively correct hypocapnia by promoting the rebreathing of carbon dioxide within the dead space of the facemask.10 A randomized controlled trial investigating psychogenic hyperventilation syndrome provides preliminary evidence for this approach, demonstrating that low-flow (3 L/min) facemask oxygen therapy can relieve symptoms more rapidly and improve patient comfort compared to traditional breathing training.11 However, high-level evidence regarding the safety, efficacy, and impact on neurological outcomes of using low-flow facemask oxygen therapy (functioning as a rebreathing mask) as a targeted intervention for correcting hypocapnia in aSAH patients remains scarce. Consequently, this proof-of-concept prospective study aims to systematically evaluate the operational safety and clinical effectiveness of rebreathing facemask oxygen therapy for correcting hypocapnia in patients with aSAH.
Interventions
BEHAVIORALNormobaric Facemask Oxygen
Oxygen is to be delivered via a rebreathing facemask (ensuring no one-way valve is present), with a fractional inspired oxygen (FiO2) of 25-41% and an oxygen flow rate of ≤ 5 L/min. The goals are to maintain patient SpO2 \> 95%, PaCO2 between 35-42 mmHg, and, where feasible (particularly in centers with the capability for monitoring), an intracranial pressure (ICP) of \< 15 mmHg.
BEHAVIORALcontrol group
Using nasal cannula for oxygen inhalation or not using oxygen inhalation at all. Monitor and record the patient's SpO2, systolic blood pressure, diastolic blood pressure, PaCO2, and also monitor the intracranial pressure (ICP) at a center with monitoring capabilities.
Sponsors
The Chinese University of Hong Kong, Shenzhen
Study design
Observational model
COHORT
Time perspective
PROSPECTIVE
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
1. Age \> 18 years. 2. Confirmed diagnosis of aneurysmal subarachnoid hemorrhage (aSAH), with the presence of an aneurysm verified by computed tomography (CT), CT angiography (CTA), or digital subtraction angiography (DSA). 3. Hunt-Hess grade II-IV. 4. Presence of hypocapnia on arterial blood gas analysis, defined as PaCO2 \< 35 mmH; 5. PaO2 \> 90 mmHg.
Exclusion criteria
1. Presence of brain herniation or refractory intracranial hypertension, defined as a baseline intracranial pressure (ICP) \> 25 mmHg that responds poorly to conventional ICP-lowering therapy; 2. Primary respiratory diseases (e.g., chronic obstructive pulmonary disease, severe asthma) known to cause chronically elevated baseline PaCO2; 3. Severe acid-base disturbances other than respiratory alkalosis. 4. Severe cardiac insufficiency, severe hepatic or renal dysfunction, malignant tumors, or other severe comorbidities that significantly impact prognosis; 5. Before the onset of the disease, the mRS score was greater than 2, and there were other factors causing disability. 6. Life expectancy \< 3 months; 7. Any other condition deemed by the investigator to pose a high risk warranting exclusion.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| modified Rankin Scale (mRS) >3 | 90-day follow-up visit | The poor neurological outcome was considered to be mRs \>3, indicating severe disability or death. The modified Rankin Scale (mRS) is a commonly used scale for measuring the degree of disability or dependence in the daily activities of people who have suffered a stroke or other causes of neurological disability. (Score Description: 0---No symptoms at all. 1---No significant disability despite symptoms; able to carry out all usual duties and activities. 2---Slight disability; unable to carry out all previous activities, but able to look after own affairs without assistance. 3---Moderate disability; requiring some help, but able to walk without assistance. 4--- Moderately severe disability; unable to walk without assistance and unable to attend to own bodily needs without assistance. 5---Severe disability; bedridden, incontinent and requiring constant nursing care and attention. 6---Dead. |
| Incidence of delayed cerebral injury (DCI) | 30 days after onset | The presence of new focal neurological signs or a documented decrease in the level of consciousness persisting for at least 1 hour (or a drop of at least 1 point in the total Glasgow Coma Scale score), deemed to be of ischemic origin, after ruling out other causes (such as hydrocephalus, toxic-metabolic disturbances, or seizures); or identification of a new cerebral infarction on CT or MRI imaging. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Glasgow Coma Score(GCS) | Enrollment, 30 days after onset, and 90-day follow-up visit | The Glasgow Outcome Scale was used as secondary outcomes. The level of consciousness was assessed using the Glasgow Coma Scale (GCS), a standardized scale ranging from 3 to 15, where higher scores indicate a better neurological status (i.e., a higher level of consciousness), and lower scores reflect more severe impairment. |
| The modified Rankin Scale (mRS) | 30 days after onset | Shift analysis of mRS scores at 30 days after onset. The modified Rankin Scale (mRS) is a commonly used scale for measuring the degree of disability or dependence in the daily activities of people who have suffered a stroke or other causes of neurological disability. (Score Description: 0---No symptoms at all. 1---No significant disability despite symptoms; able to carry out all usual duties and activities. 2---Slight disability; unable to carry out all previous activities, but able to look after own affairs without assistance. 3---Moderate disability; requiring some help, but able to walk without assistance. 4--- Moderately severe disability; unable to walk without assistance and unable to attend to own bodily needs without assistance. 5---Severe disability; bedridden, incontinent and requiring constant nursing care and attention. 6---Dead. The higher scores indicate worse functional disability and lower scores reflect better functional independence. |
| modified Rankin Scale (mRS) | 30 days after onset | The rate of modified Rankin Scale (mRS) score \> 3. The modified Rankin Scale (mRS) is a commonly used scale for measuring the degree of disability or dependence in the daily activities of people who have suffered a stroke or other causes of neurological disability. (Score Description: 0---No symptoms at all. 1---No significant disability despite symptoms; able to carry out all usual duties and activities. 2---Slight disability; unable to carry out all previous activities, but able to look after own affairs without assistance. 3---Moderate disability; requiring some help, but able to walk without assistance. 4--- Moderately severe disability; unable to walk without assistance and unable to attend to own bodily needs without assistance. 5---Severe disability; bedridden, incontinent and requiring constant nursing care and attention. 6---Dead. The higher scores indicate worse functional disability and lower scores reflect better functional independence. |
| Barthel Index (BI) score | 90-day follow-up visit | Activities of daily living were evaluated using the Barthel Index (BI), a functional assessment scale ranging from 0 to 100, where higher scores indicate greater independence in daily activities and lower scores reflect more severe functional dependence. |
| Montreal Cognitive Assessment (MoCA) | 90-day follow-up visit | Cognitive function was evaluated using the Montreal Cognitive Assessment (MoCA), a standardized screening tool with scores ranging from 0 to 30, where higher scores indicate better cognitive performance and lower scores reflect greater cognitive impairment. Measure mean score or median compared between groups. And the rate of MoCA score of 20 or less between groups. |
| Complication of severe dependent survival | 90-day follow-up visit | eg, chest or other infections |
| Treated aneurysm rebleeding | 90-day follow-up visit | Treated aneurysm rebleeding |
| Probable or definite bleed from another aneurysm | 90-day follow-up visit | Probable or definite bleed from another aneurysm |
| Incidence of adverse events | 90-day follow-up visit | Ischaemic stroke, Other intracranial haemorrhage, Cardiac, Cancer, Suicide, Renal failure, Infections not related to dependent survival, Other causes (eg, trauma, perforated ulcer, pulmonary embolus, neurodegenerative) |
| All-cause mortality | 90-day follow-up visit | Death caused by any reason. |
| Cerebral Vasospasm | Participants will be followed for the duration of the hospital stay, an expected average of 2 weeks | Incidence of moderate and severe radiographic cerebral vasospasm (catheter angiogram, CTA, MRA) or incidence OR moderate and severe vasospasm by transcranial doppler (TCD) criteria. |
Countries
China
Contacts
Primary ContactXinyu Yang, MD
Outcome results
None listed