Venous Air Embolism Pekka Talke MD University of
Venous Air Embolism Pekka Talke, MD University of California, San Francisco 2009
Procedures in Sitting Position • Cervical laminectomies • Posterior fossa surgeries • Becoming relatively uncommon but associated with high rates of complications
Benefits of Sitting Position • • Better surgical exposure Less tissue retraction Less bleeding Less cranial nerve damage
Complications of Sitting Position • • Spinal cord infarct Ulnar nerve compression Sciatic nerve damage Lateral peroneal nerve compression Cardiovascular changes Airway obstruction -tube kinking, migration Tension pneumocephalus Venous Air Embolism (VAE) (40%)
VAE detection, sensitivity Doppler, TEE ET N 2 Pa. O 2 ET CO 2, PAP Pa. CO 2 CVP CO BP ECG, esoph. steth.
Monitoring for Sitting Position • • • ECG Temperature Muscle relaxation ��Pulse oximeter ET CO 2, ET anesthetic agent, ET N 2 Arterial blood pressure (cpp) Central venous pressure (cvp, pap) Precordial Doppler Esophageal stethoscope
Monitoring for Sitting Position • • • ECG Temperature Muscle relaxation Pulse oximeter ET CO 2, ET anesthetic agent, ET N 2 Arterial blood pressure (cpp) Central venous pressure (cvp, pap) Precordial Doppler Esophageal stethoscope
Doppler (VAE) • • • Very sensitive 3 -6 th interspace, right of sternum 2. 2 MHz probe Blood, wall motion, air Early detection/prevention
Doppler equipment
Doppler probe 2. 25 MHz flat probe 3/4’’ ultrasound beam at surface
Doppler equipment Model 915 -BL or Model 614 -B 2 MHz flat probe
Doppler equipment
Precordial Doppler Placement
Doppler record keeping
ET CO 2 changes with VAE • Sudden decrease in ET CO 2 within a few breaths after VAE • ET CO 2 decrease proportional to VAE magnitude • ET CO 2 starts to recover once VAE stops
ET CO 2 trend changes with VAE
CVP catheter (VAE) • • • Positioning: ECG, X-ray, pressure tracing Positioning in sitting position - migration Can be used to confirm Doppler placement Aspiration: confirmation of VAE, treatment? (PA catheter: diagnosis, resolution)
CVP Catheter
CVP Catheter
CVP Catheter
CVP Catheter
Placement of CVP Catheter From Clinical Neuroanesthesia, Cucchiara et al
Placement of CVP Catheter From Clinical Neuroanesthesia, Cucchiara et al
VAE Detection - Awake • • Cough Chest pain Bronchospasm Hypoxia
Rapid, Large VAE • • • Rare Catastrophic Air lock in right heart Right sided heart failure Reduced CO Cardiovascular collapse
Slow, Continuous VAE • • • Common Air bubbles entrapped in pulmonary circulation Local hypoxemia/obstruction Sympathetic reflex vasoconstriction Pulmonary HTN, hypoxemia, CO 2 retention, increased dead space, decreased ET CO 2 • Bronchoconstriction
M&M from VAE • • • Right heart failure Hypoxia - immediate, delayed (ARDS) Paradoxical Air Embolus (PAE) – incidence unknown – potential for neurologic deficits – PFO (20 -30%)
Treatment of VAE • • • 100% O 2 Flood field, bone wax Jugular pressure Volume, vasopressors, supine CPR
Venous Air Embolism • Prevention - avoid hypovolemia, good surgical technique • Early detection • Treatment
neuroanesthesia. ucsf. edu Thank You
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