Introduction: The ultrasound-guided axillary vein is becoming a compulsory alternative vessel for central venous catheterization and the anatomical position offers several potential advantages over blind, subclavian vein techniques. Objective: To determine the degree of dynamic variation of the axillary vein size measured by ultrasound prior to the induction of general anesthesia and after starting controlled mechanical ventilation. Design: Prospective, observational study. Methods: One hundred ten patients undergoing elective surgery were enrolled and classified according to sex, age, and body mass index. Two-dimensional cross-sectional vein diameter, area, and mean flow velocity were performed using ultrasound on both the left and right axillary veins of each subject before and after induction of anesthesia. Results: There was statistically significant evidence showing that the axillary vein area increases when patients are mechanically ventilated. When considering venous flow velocity as a primary outcome, velocity decreased after patients moved from spontaneous to mechanical ventilation (coefficient = −0.267), but this relationship failed to achieve statistical significance ( t = –1.355, p = 0.179). Conclusions: Anatomical variations in depth and diameter as well as the collapsibility due to intrathoracic pressures changes represent common challenges that face clinicians during central venous catheterization of the axillary vein. A noteworthy increase in vessel size as patients transition from spontaneous to mechanical ventilation may theoretically improve first-pass cannulation success with practitioners skilled in both ultrasound and procedure. As a result, placing a centrally inserted central catheter after the induction of anesthesia may be beneficial.

There is an increased use of oral anticoagulants for the prevention of venous and arterial thrombosis. Vitamin-K antagonists have been used for decades as the main oral anticoagulants but they have the draback a complex therapeutic management, slow onset of action and by a different oral intake caused by dietary vitamin K intake. New non-vitamin K antagonist oral anticoagulants (NOACs) have been developed to overcome the limitations of warfarin. Their management is easier as it requires a fixed daily dose without coagulation monitoring. Although their therapeutic profile is safe, proper attention should be paid in case of unexpected need for the reversal of their coagulation effect and in case a patient needs to have a scheduled surgery. For non-acute cardiac surgery, discontinuation of NOACs should start at least 48 hours prior surgery. Intracranial bleedings associated with NOACs are less dangerous comparing to those warfarin-induced. NOACs need to be stopped ≥24 hours in case of elective surgery for low bleeding-risk procedures and ≥48 hours for high bleeding-risk surgery in patients with normal renal function and 72 hours in case of reduced CrCl < 80. The therapy with NOACs should be resumed from 48 to 72 hours after the procedure depending on the perceived bleeding, type of surgery and thrombotic risks. There are some available NOAC reversal agents acting within 5 to 20 minutes. In case of lack of reversal agent, adequate diuresis, renal replacement therapy and activated charcoal in case of recent ingestion should be considered.

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