Most sensitive investigation for air embolism is –

Although transesophageal echocardiography (TEE) is the most sensitive method for venous air embolism (VAE) detection and is considered the "gold standard", it is costly and more invasive. When properly placed, a precordial Doppler is capable of identifying VAE at an air infusion rate as low as 0.015 ml/kg/ min and consistently at a rate of 0.021 ml/kg/ min.