Anesthesiology and Intensive Care

    Patients with hypotension and shock without other cause are considered to have massive Pulmonary Embolism (PE) .     When obstruction occurs by embolism, the RV experiences an acute rise in pressure and volume, causing shift of the interventricular septum toward the left ventricle. In addition, as RV output  decreases,

    Any procedure where the operative site is higher than the right atrium and where the vasculature is exposed in a surgical field carries a risk of air embolism. The addition of a pressure gradient between the surgical site and the right heart substantially increases the risk. A pressure difference as small as 5 cm of water will allow 100 ml of air entrainment per second via a 14-gauge cannula. This is the rational for head down position during central venous cannulation. Hypovolaemia and negative pressure associated with spontaneous respiration will also increase the pressure difference and hence the risk.    Additional risks include interventions accessing the circulation such as central venous cann itional risks include intervention ulation (causing air embolism) or using carbon dioxide insufflation during laparoscopic surgery (causing CO2 embolism). Air may also be inadvertently injected via a vascular access device. The risk factors for air embolism...