A patient had a massive bleeding during surgery. Which sized cannula should be used?

Ans. a. 16 Gauge (Ref: Bailey 25/e p291)In a patient with massive bleeding, there is always a risk of patient going into shock and widest bore cannula available showed be used for cannulation. The ACLS guidelines recommend securing intravenous access with two large-bore cannulae (14-16G) in a patient needing resuscitation."Primary surrey in Trauma: These include blood samples for full blood count (FBC), coagidation studies, plasma chemistry (urea and electrolytes and, sometimes, toxicology or other case-specific indices), transfusion screening (group and cross-match, etc,), 12-lead electrocardiography (ECG) monitoring and pulse oximetry, if available. The blood can be taken at the same time as securing intravenous access with two large-bore cannulae (14--16G)."- Bailey 25/e p29"The sizes of needle-based instruments (such as Venflons and needles themselves) are measured in 'Gauge' (i.e. how many can be fitted into a tube of a fixed diameter). In Gauge, larger numbers, mean smaller diameter lumens. Catheters use the 'French 'system. This is the circumference of the tube in millimeters, e.g. a 30 F catheter has a circumference of 30 mm. In French, larger numbers therefore mean larger diameter lumens. "GaugeColor codeExternal DiameterLengthFlow Rate14GOrange2.1 mm45 mm240 ml/min16GGrey1.8 mm45 mm180 ml/min18GGreen1.3 mm32/45 mm90 ml/min20GPink1.1 mm32 mm60 ml/min22GBlue0.9 mm25 mm36 ml/min24GYellow0.7 mm19 mm20 ml/min26GViolet0.6 mm19 mm13 ml/min