A patient is undergoing MRND for laryngeal malignancy; while dissecting the venous tributaries the surgeon elevated the internal jugular vein for ligation. Suddenly the patients EtCO2 dropped from 3g mmHg to 12 mmHg and the patient developed hypotension along with cardiac arrhythmia. Which of the following is most likely cause??
(A) Sympathetic overactivity (B) Vagal stimulation (C) Venous air embolism (D) Carotid body stimulation
(C) Ans: C: Venous air embolismRef Millers anesthesia &h ed-, pg. 2170.Diagnosis standard of care is precordial doppler (left or right parastemal, between 2nd and 3rd ribs) + ETC02 monitoring although this is not the most sensitive test - TEE is most sensitive.Pulmonary aery pressure will rise, and CO2 will fall alter VAE.