What is the management plan for a patient suspected of having air bubbles causing strokes post-mitral valve repair during hyperbaric (high-pressure oxygen) treatment?

Management of Suspected Air Embolism Stroke Post-Mitral Valve Repair

Immediate hyperbaric oxygen therapy (HBOT) is the definitive treatment for suspected air embolism stroke following mitral valve repair, and transfer to a hyperbaric facility should be coordinated urgently while stabilizing the patient. 1

Critical Distinction in Treatment Approach

This scenario requires recognition that air embolism stroke is fundamentally different from routine ischemic stroke:

• The American Heart Association/American Stroke Association explicitly recommends HBOT for ischemic neurological symptoms secondary to air embolism 1
• HBOT is not recommended for routine acute ischemic stroke (Class III: No Benefit), but air embolism is the specific exception to this rule 1
• Air embolization is a recognized risk during mitral valve procedures, occurring from inadequate de-airing techniques, manipulation of delivery catheters, or device-related issues 2, 3

Immediate Management Algorithm

Step 1: Recognize Air Embolism

• High clinical suspicion is warranted in any patient developing acute neurological deficits during or immediately after mitral valve repair 2
• Air embolism during transcatheter mitral procedures can originate from delivery systems, device components, or transseptal puncture sites 2, 3

Step 2: Stabilize and Coordinate Transfer

• Coordinate immediate transfer to a hyperbaric facility while stabilizing the patient 1
• Maintain adequate oxygenation and hemodynamic support during transfer 4
• Do not delay HBOT initiation for extensive diagnostic workup if clinical suspicion is high 4, 5

Step 3: Initiate Hyperbaric Oxygen Therapy

• HBOT remains effective even with significant delays (up to 18-48 hours post-event) 4, 3, 5
• Treatment involves 100% oxygen at 1.5-3.0 atmospheres absolute, which dramatically increases dissolved oxygen in plasma and reduces gas bubble size 1
• In one case series of 12 post-cardiac surgical stroke patients, 10 made full or near-full neurological recovery despite delays up to 48 hours 4
• A case report demonstrated complete recovery with HBOT initiated more than 18 hours after air embolism during MitraClip procedure 3

Adjunctive Considerations

Aspiration Technique (If Detected Intra-procedurally)

• Real-time echocardiography-guided aspiration of air from the ascending aorta can be performed if massive air embolism is detected during the procedure 6
• This technique requires immediate recognition via transesophageal echocardiography and can prevent downstream embolization 6

Anticoagulation Management

• Maintain adequate intraprocedural anticoagulation (activated clotting time 200-300 seconds) to minimize concurrent thrombus formation 2
• Post-procedure anticoagulation decisions should follow standard protocols for the specific mitral intervention performed 2
• For transcatheter edge-to-edge repair (TEER), dual antiplatelet therapy for 1-6 months is typically recommended in OAC-naive patients 2

Safety Profile of HBOT

HBOT carries minimal risk in the context of air embolism stroke 1:

• Side effects are generally limited to transient myopia, middle ear/sinus barotrauma, claustrophobia, and rarely seizures 1
• The presence of cardiac devices or recent cardiac surgery is not a contraindication to HBOT for cerebral air embolism 7

Expected Outcomes

• Excellent neurological recovery is achievable even with delayed treatment 4, 3, 5
• In the largest case series, 9 of 12 patients returned to their previous level of care, with only one patient remaining hemiplegic and one early death 4
• Complete recovery has been documented even when HBOT was initiated 30 hours post-embolism 5

Common Pitfalls to Avoid

• Do not withhold HBOT due to time elapsed since the event - effectiveness persists beyond typical ischemic stroke treatment windows 4, 3, 5
• Do not confuse this with routine ischemic stroke management - standard stroke protocols (thrombolytics, thrombectomy) do not address gas emboli 1
• Do not delay transfer for extensive imaging if clinical presentation strongly suggests air embolism 4