At the commencement of surgery a bolus of Hartmann's balanced salt crystalloid 10 ml/kg followed by 8 ml/kg/h will be administered until the end of surgery. A maintenance infusion will then continue at 1.5 ml/kg/h, for at least 24 hours, but this can be reduced postoperatively if there is evidence of fluid overload and no hypotension, and increased if there is evidence of hypovolaemia or hypotension. Alternative fluid types (crystalloid, dextrose, colloid) and electrolyte supplements will be allowed postoperatively in order to account for local preferences and patient biochemistry, for which we will collect data.

Liberal fluid therapy: Liberal protocol group is designed to provide approximately 6.0L per day.

Will provide less than 2.0 L water and 120 mmol sodium per day. Induction of anaesthesia will limit IV bolus fluid to ≤5 ml/kg; no other IV fluids will be used at the commencement of surgery (unless indicated by goal-directed device [see below]). Hartmann's balanced salt crystalloid 5 ml/kg/h will be administered until the end of surgery, and bolus colloid/blood used intraoperatively to replace blood loss (ml for ml); then an infusion at 1 ml/kg/h until expedited cessation of IV fluid therapy within 24 hours. The rate of postoperative fluid replacement can be reduced if there is evidence of fluid overload and no hypotension, and can be increased if there is hypotension AND evidence of hypovolaemia.

Restrictive fluid therapy: Restrictive protocol group is designed to provide less than 2.0 L water and 120 mmol sodium per day.

At the commencement of surgery a bolus of Hartmann's balanced salt crystalloid 10 ml/kg followed by 8 ml/kg/h will be administered until the end of surgery. A maintenance infusion will then continue at 1.5 ml/kg/h, for at least 24 hours, but this can be reduced postoperatively if there is evidence of fluid overload and no hypotension, and increased if there is evidence of hypovolaemia or hypotension. Alternative fluid types (crystalloid, dextrose, colloid) and electrolyte supplements will be allowed postoperatively in order to account for local preferences and patient biochemistry, for which we will collect data.

Liberal fluid therapy: Liberal protocol group is designed to provide approximately 6.0L per day.

Will provide less than 2.0 L water and 120 mmol sodium per day. Induction of anaesthesia will limit IV bolus fluid to ≤5 ml/kg; no other IV fluids will be used at the commencement of surgery (unless indicated by goal-directed device [see below]). Hartmann's balanced salt crystalloid 5 ml/kg/h will be administered until the end of surgery, and bolus colloid/blood used intraoperatively to replace blood loss (ml for ml); then an infusion at 1 ml/kg/h until expedited cessation of IV fluid therapy within 24 hours. The rate of postoperative fluid replacement can be reduced if there is evidence of fluid overload and no hypotension, and can be increased if there is hypotension AND evidence of hypovolaemia.

Restrictive fluid therapy: Restrictive protocol group is designed to provide less than 2.0 L water and 120 mmol sodium per day.

At the commencement of surgery a bolus of Hartmann's balanced salt crystalloid 10 ml/kg followed by 8 ml/kg/h will be administered until the end of surgery. A maintenance infusion will then continue at 1.5 ml/kg/h, for at least 24 hours, but this can be reduced postoperatively if there is evidence of fluid overload and no hypotension, and increased if there is evidence of hypovolaemia or hypotension. Alternative fluid types (crystalloid, dextrose, colloid) and electrolyte supplements will be allowed postoperatively in order to account for local preferences and patient biochemistry, for which we will collect data.

Liberal fluid therapy: Liberal protocol group is designed to provide approximately 6.0L per day.

Will provide less than 2.0 L water and 120 mmol sodium per day. Induction of anaesthesia will limit IV bolus fluid to ≤5 ml/kg; no other IV fluids will be used at the commencement of surgery (unless indicated by goal-directed device [see below]). Hartmann's balanced salt crystalloid 5 ml/kg/h will be administered until the end of surgery, and bolus colloid/blood used intraoperatively to replace blood loss (ml for ml); then an infusion at 1 ml/kg/h until expedited cessation of IV fluid therapy within 24 hours. The rate of postoperative fluid replacement can be reduced if there is evidence of fluid overload and no hypotension, and can be increased if there is hypotension AND evidence of hypovolaemia.

Restrictive fluid therapy: Restrictive protocol group is designed to provide less than 2.0 L water and 120 mmol sodium per day.

At the commencement of surgery a bolus of Hartmann's balanced salt crystalloid 10 ml/kg followed by 8 ml/kg/h will be administered until the end of surgery. A maintenance infusion will then continue at 1.5 ml/kg/h, for at least 24 hours, but this can be reduced postoperatively if there is evidence of fluid overload and no hypotension, and increased if there is evidence of hypovolaemia or hypotension. Alternative fluid types (crystalloid, dextrose, colloid) and electrolyte supplements will be allowed postoperatively in order to account for local preferences and patient biochemistry, for which we will collect data.

Liberal fluid therapy: Liberal protocol group is designed to provide approximately 6.0L per day.

Will provide less than 2.0 L water and 120 mmol sodium per day. Induction of anaesthesia will limit IV bolus fluid to ≤5 ml/kg; no other IV fluids will be used at the commencement of surgery (unless indicated by goal-directed device [see below]). Hartmann's balanced salt crystalloid 5 ml/kg/h will be administered until the end of surgery, and bolus colloid/blood used intraoperatively to replace blood loss (ml for ml); then an infusion at 1 ml/kg/h until expedited cessation of IV fluid therapy within 24 hours. The rate of postoperative fluid replacement can be reduced if there is evidence of fluid overload and no hypotension, and can be increased if there is hypotension AND evidence of hypovolaemia.

Restrictive fluid therapy: Restrictive protocol group is designed to provide less than 2.0 L water and 120 mmol sodium per day.

At the commencement of surgery a bolus of Hartmann's balanced salt crystalloid 10 ml/kg followed by 8 ml/kg/h will be administered until the end of surgery. A maintenance infusion will then continue at 1.5 ml/kg/h, for at least 24 hours, but this can be reduced postoperatively if there is evidence of fluid overload and no hypotension, and increased if there is evidence of hypovolaemia or hypotension. Alternative fluid types (crystalloid, dextrose, colloid) and electrolyte supplements will be allowed postoperatively in order to account for local preferences and patient biochemistry, for which we will collect data.

Liberal fluid therapy: Liberal protocol group is designed to provide approximately 6.0L per day.

Will provide less than 2.0 L water and 120 mmol sodium per day. Induction of anaesthesia will limit IV bolus fluid to ≤5 ml/kg; no other IV fluids will be used at the commencement of surgery (unless indicated by goal-directed device [see below]). Hartmann's balanced salt crystalloid 5 ml/kg/h will be administered until the end of surgery, and bolus colloid/blood used intraoperatively to replace blood loss (ml for ml); then an infusion at 1 ml/kg/h until expedited cessation of IV fluid therapy within 24 hours. The rate of postoperative fluid replacement can be reduced if there is evidence of fluid overload and no hypotension, and can be increased if there is hypotension AND evidence of hypovolaemia.

Restrictive fluid therapy: Restrictive protocol group is designed to provide less than 2.0 L water and 120 mmol sodium per day.

At the commencement of surgery a bolus of Hartmann's balanced salt crystalloid 10 ml/kg followed by 8 ml/kg/h will be administered until the end of surgery. A maintenance infusion will then continue at 1.5 ml/kg/h, for at least 24 hours, but this can be reduced postoperatively if there is evidence of fluid overload and no hypotension, and increased if there is evidence of hypovolaemia or hypotension. Alternative fluid types (crystalloid, dextrose, colloid) and electrolyte supplements will be allowed postoperatively in order to account for local preferences and patient biochemistry, for which we will collect data.

Liberal fluid therapy: Liberal protocol group is designed to provide approximately 6.0L per day.

Will provide less than 2.0 L water and 120 mmol sodium per day. Induction of anaesthesia will limit IV bolus fluid to ≤5 ml/kg; no other IV fluids will be used at the commencement of surgery (unless indicated by goal-directed device [see below]). Hartmann's balanced salt crystalloid 5 ml/kg/h will be administered until the end of surgery, and bolus colloid/blood used intraoperatively to replace blood loss (ml for ml); then an infusion at 1 ml/kg/h until expedited cessation of IV fluid therapy within 24 hours. The rate of postoperative fluid replacement can be reduced if there is evidence of fluid overload and no hypotension, and can be increased if there is hypotension AND evidence of hypovolaemia.

Restrictive fluid therapy: Restrictive protocol group is designed to provide less than 2.0 L water and 120 mmol sodium per day.

At the commencement of surgery a bolus of Hartmann's balanced salt crystalloid 10 ml/kg followed by 8 ml/kg/h will be administered until the end of surgery. A maintenance infusion will then continue at 1.5 ml/kg/h, for at least 24 hours, but this can be reduced postoperatively if there is evidence of fluid overload and no hypotension, and increased if there is evidence of hypovolaemia or hypotension. Alternative fluid types (crystalloid, dextrose, colloid) and electrolyte supplements will be allowed postoperatively in order to account for local preferences and patient biochemistry, for which we will collect data.

Liberal fluid therapy: Liberal protocol group is designed to provide approximately 6.0L per day.

Will provide less than 2.0 L water and 120 mmol sodium per day. Induction of anaesthesia will limit IV bolus fluid to ≤5 ml/kg; no other IV fluids will be used at the commencement of surgery (unless indicated by goal-directed device [see below]). Hartmann's balanced salt crystalloid 5 ml/kg/h will be administered until the end of surgery, and bolus colloid/blood used intraoperatively to replace blood loss (ml for ml); then an infusion at 1 ml/kg/h until expedited cessation of IV fluid therapy within 24 hours. The rate of postoperative fluid replacement can be reduced if there is evidence of fluid overload and no hypotension, and can be increased if there is hypotension AND evidence of hypovolaemia.

Restrictive fluid therapy: Restrictive protocol group is designed to provide less than 2.0 L water and 120 mmol sodium per day.

At the commencement of surgery a bolus of Hartmann's balanced salt crystalloid 10 ml/kg followed by 8 ml/kg/h will be administered until the end of surgery. A maintenance infusion will then continue at 1.5 ml/kg/h, for at least 24 hours, but this can be reduced postoperatively if there is evidence of fluid overload and no hypotension, and increased if there is evidence of hypovolaemia or hypotension. Alternative fluid types (crystalloid, dextrose, colloid) and electrolyte supplements will be allowed postoperatively in order to account for local preferences and patient biochemistry, for which we will collect data.

Liberal fluid therapy: Liberal protocol group is designed to provide approximately 6.0L per day.

Will provide less than 2.0 L water and 120 mmol sodium per day. Induction of anaesthesia will limit IV bolus fluid to ≤5 ml/kg; no other IV fluids will be used at the commencement of surgery (unless indicated by goal-directed device [see below]). Hartmann's balanced salt crystalloid 5 ml/kg/h will be administered until the end of surgery, and bolus colloid/blood used intraoperatively to replace blood loss (ml for ml); then an infusion at 1 ml/kg/h until expedited cessation of IV fluid therapy within 24 hours. The rate of postoperative fluid replacement can be reduced if there is evidence of fluid overload and no hypotension, and can be increased if there is hypotension AND evidence of hypovolaemia.

Restrictive fluid therapy: Restrictive protocol group is designed to provide less than 2.0 L water and 120 mmol sodium per day.

At the commencement of surgery a bolus of Hartmann's balanced salt crystalloid 10 ml/kg followed by 8 ml/kg/h will be administered until the end of surgery. A maintenance infusion will then continue at 1.5 ml/kg/h, for at least 24 hours, but this can be reduced postoperatively if there is evidence of fluid overload and no hypotension, and increased if there is evidence of hypovolaemia or hypotension. Alternative fluid types (crystalloid, dextrose, colloid) and electrolyte supplements will be allowed postoperatively in order to account for local preferences and patient biochemistry, for which we will collect data.

Liberal fluid therapy: Liberal protocol group is designed to provide approximately 6.0L per day.

Will provide less than 2.0 L water and 120 mmol sodium per day. Induction of anaesthesia will limit IV bolus fluid to ≤5 ml/kg; no other IV fluids will be used at the commencement of surgery (unless indicated by goal-directed device [see below]). Hartmann's balanced salt crystalloid 5 ml/kg/h will be administered until the end of surgery, and bolus colloid/blood used intraoperatively to replace blood loss (ml for ml); then an infusion at 1 ml/kg/h until expedited cessation of IV fluid therapy within 24 hours. The rate of postoperative fluid replacement can be reduced if there is evidence of fluid overload and no hypotension, and can be increased if there is hypotension AND evidence of hypovolaemia.

Restrictive fluid therapy: Restrictive protocol group is designed to provide less than 2.0 L water and 120 mmol sodium per day.

At the commencement of surgery a bolus of Hartmann's balanced salt crystalloid 10 ml/kg followed by 8 ml/kg/h will be administered until the end of surgery. A maintenance infusion will then continue at 1.5 ml/kg/h, for at least 24 hours, but this can be reduced postoperatively if there is evidence of fluid overload and no hypotension, and increased if there is evidence of hypovolaemia or hypotension. Alternative fluid types (crystalloid, dextrose, colloid) and electrolyte supplements will be allowed postoperatively in order to account for local preferences and patient biochemistry, for which we will collect data.

Liberal fluid therapy: Liberal protocol group is designed to provide approximately 6.0L per day.

Will provide less than 2.0 L water and 120 mmol sodium per day. Induction of anaesthesia will limit IV bolus fluid to ≤5 ml/kg; no other IV fluids will be used at the commencement of surgery (unless indicated by goal-directed device [see below]). Hartmann's balanced salt crystalloid 5 ml/kg/h will be administered until the end of surgery, and bolus colloid/blood used intraoperatively to replace blood loss (ml for ml); then an infusion at 1 ml/kg/h until expedited cessation of IV fluid therapy within 24 hours. The rate of postoperative fluid replacement can be reduced if there is evidence of fluid overload and no hypotension, and can be increased if there is hypotension AND evidence of hypovolaemia.

Restrictive fluid therapy: Restrictive protocol group is designed to provide less than 2.0 L water and 120 mmol sodium per day.

At the commencement of surgery a bolus of Hartmann's balanced salt crystalloid 10 ml/kg followed by 8 ml/kg/h will be administered until the end of surgery. A maintenance infusion will then continue at 1.5 ml/kg/h, for at least 24 hours, but this can be reduced postoperatively if there is evidence of fluid overload and no hypotension, and increased if there is evidence of hypovolaemia or hypotension. Alternative fluid types (crystalloid, dextrose, colloid) and electrolyte supplements will be allowed postoperatively in order to account for local preferences and patient biochemistry, for which we will collect data.

Liberal fluid therapy: Liberal protocol group is designed to provide approximately 6.0L per day.

Will provide less than 2.0 L water and 120 mmol sodium per day. Induction of anaesthesia will limit IV bolus fluid to ≤5 ml/kg; no other IV fluids will be used at the commencement of surgery (unless indicated by goal-directed device [see below]). Hartmann's balanced salt crystalloid 5 ml/kg/h will be administered until the end of surgery, and bolus colloid/blood used intraoperatively to replace blood loss (ml for ml); then an infusion at 1 ml/kg/h until expedited cessation of IV fluid therapy within 24 hours. The rate of postoperative fluid replacement can be reduced if there is evidence of fluid overload and no hypotension, and can be increased if there is hypotension AND evidence of hypovolaemia.

Restrictive fluid therapy: Restrictive protocol group is designed to provide less than 2.0 L water and 120 mmol sodium per day.

At the commencement of surgery a bolus of Hartmann's balanced salt crystalloid 10 ml/kg followed by 8 ml/kg/h will be administered until the end of surgery. A maintenance infusion will then continue at 1.5 ml/kg/h, for at least 24 hours, but this can be reduced postoperatively if there is evidence of fluid overload and no hypotension, and increased if there is evidence of hypovolaemia or hypotension. Alternative fluid types (crystalloid, dextrose, colloid) and electrolyte supplements will be allowed postoperatively in order to account for local preferences and patient biochemistry, for which we will collect data.

Liberal fluid therapy: Liberal protocol group is designed to provide approximately 6.0L per day.

Will provide less than 2.0 L water and 120 mmol sodium per day. Induction of anaesthesia will limit IV bolus fluid to ≤5 ml/kg; no other IV fluids will be used at the commencement of surgery (unless indicated by goal-directed device [see below]). Hartmann's balanced salt crystalloid 5 ml/kg/h will be administered until the end of surgery, and bolus colloid/blood used intraoperatively to replace blood loss (ml for ml); then an infusion at 1 ml/kg/h until expedited cessation of IV fluid therapy within 24 hours. The rate of postoperative fluid replacement can be reduced if there is evidence of fluid overload and no hypotension, and can be increased if there is hypotension AND evidence of hypovolaemia.

Restrictive fluid therapy: Restrictive protocol group is designed to provide less than 2.0 L water and 120 mmol sodium per day.

At the commencement of surgery a bolus of Hartmann's balanced salt crystalloid 10 ml/kg followed by 8 ml/kg/h will be administered until the end of surgery. A maintenance infusion will then continue at 1.5 ml/kg/h, for at least 24 hours, but this can be reduced postoperatively if there is evidence of fluid overload and no hypotension, and increased if there is evidence of hypovolaemia or hypotension. Alternative fluid types (crystalloid, dextrose, colloid) and electrolyte supplements will be allowed postoperatively in order to account for local preferences and patient biochemistry, for which we will collect data.

Liberal fluid therapy: Liberal protocol group is designed to provide approximately 6.0L per day.

Will provide less than 2.0 L water and 120 mmol sodium per day. Induction of anaesthesia will limit IV bolus fluid to ≤5 ml/kg; no other IV fluids will be used at the commencement of surgery (unless indicated by goal-directed device [see below]). Hartmann's balanced salt crystalloid 5 ml/kg/h will be administered until the end of surgery, and bolus colloid/blood used intraoperatively to replace blood loss (ml for ml); then an infusion at 1 ml/kg/h until expedited cessation of IV fluid therapy within 24 hours. The rate of postoperative fluid replacement can be reduced if there is evidence of fluid overload and no hypotension, and can be increased if there is hypotension AND evidence of hypovolaemia.

Restrictive fluid therapy: Restrictive protocol group is designed to provide less than 2.0 L water and 120 mmol sodium per day.

At the commencement of surgery a bolus of Hartmann's balanced salt crystalloid 10 ml/kg followed by 8 ml/kg/h will be administered until the end of surgery. A maintenance infusion will then continue at 1.5 ml/kg/h, for at least 24 hours, but this can be reduced postoperatively if there is evidence of fluid overload and no hypotension, and increased if there is evidence of hypovolaemia or hypotension. Alternative fluid types (crystalloid, dextrose, colloid) and electrolyte supplements will be allowed postoperatively in order to account for local preferences and patient biochemistry, for which we will collect data.

Liberal fluid therapy: Liberal protocol group is designed to provide approximately 6.0L per day.

Will provide less than 2.0 L water and 120 mmol sodium per day. Induction of anaesthesia will limit IV bolus fluid to ≤5 ml/kg; no other IV fluids will be used at the commencement of surgery (unless indicated by goal-directed device [see below]). Hartmann's balanced salt crystalloid 5 ml/kg/h will be administered until the end of surgery, and bolus colloid/blood used intraoperatively to replace blood loss (ml for ml); then an infusion at 1 ml/kg/h until expedited cessation of IV fluid therapy within 24 hours. The rate of postoperative fluid replacement can be reduced if there is evidence of fluid overload and no hypotension, and can be increased if there is hypotension AND evidence of hypovolaemia.

Restrictive fluid therapy: Restrictive protocol group is designed to provide less than 2.0 L water and 120 mmol sodium per day.