The Effect of Intraoperative Goal Directed Restricted Fluid Therapy on Extravascular Lung Water
Condition: Surgery
Study type: Interventional

Summary: 
      The aim of this study is to compare the use of Goal Directed fluid therapy guided by Stroke
      volume variation plus a restricted fluid management approach to standard fluid management in
      patients undergoing major abdominal operations.
    

Detailed description: 
      Perioperative fluid management has an important impact on patient outcome.
      Under-resuscitation leads to hypoperfusion and over-resuscitation leads to tissue oedema.
      Intraoperative goal directed fluid therapy (GDT) has been reported to improve patient outcome
      in high risk surgical patients. GDT aims to optimize oxygen delivery through various
      strategies. The main three GDT strategies are:

        1. Stroke volume optimization with fluids

        2. Stroke volume variation (SVV) and pulse pressure variation (PPV) optimization with
           fluids.

        3. Oxygen delivery index with fluids and inotropes Although GDT was recommended by
           professional societies in Europe and United Kingdom, these recommendations were recently
           challenged in many randomized controlled trials and meta-analysis.The effect of GDT on
           intraoperative fluid requirements was previously reported, however; its effect on
           extravascular lung water is not well studied.

      Electrical cardiometry is a recent non-invasive technology for cardiac output measurement.
      Electrical cardiometry drive CO measurement from thoracic electrical bioimpedance. Good
      correlation was reported between CO measurements derived from electrical cardiometry and
      continuous thermodilution monitoring system.

      Although many protocols for GDT have been reported in major abdominal operations, till now
      there is no consensus about the optimum protocol nor the optimum goals to achieve during
      fluid management. Major abdominal operations are characterized by major fluid shifts.
      Moreover, patients undergoing these operations are prone to impaired organ functions due to
      tissue oedema. Traditional standard care in major abdominal operations usually includes 6
      ml/Kg/h balanced crystalloids (to restore insensible losses and maintenance requirements) in
      addition to replacement of blood losses. We hypothesize that the use of a more restricted
      fluid approach (2ml/Kg/h) + GDT guided by cardiometry will improve fluid management and
      decrease extra-vascular lung water.

      The aim of this study is to compare the use of Goal Directed fluid therapy guided by Stroke
      volume variation plus a restricted fluid management approach to standard fluid management in
      patients undergoing major abdominal operations.
    

Intervention name(s): Restricted fluid therapy group; Standard fluid management
Intervention type(s): Procedure; Procedure
Intervention description(s): Patients will receive restricted fluid management (2ml/Kg/h) with concomitant SVV monitoring using ICON cardiometry device. GDT protocol will be used to fulfil the two targets (SVV < 10% - MAP >65 mmHg). A fluid bolus of 200 ml Lactated ringer will be infused if SVV is more than 10% for 5 minutes, the dose will be repeated every 10 minutes if SVV is still above 10%. If the total fluid boluses reached 20 ml/Kg in a patient with MAP > 65 mmHg, no fluid boluses will be infused unless there is evident blood loss or hypotension. If MAP was achieved (>65mmHg) at any time, the first three steps in the protocol will be bypassed. If MAP was not achieved after reaching 20 ml/Kg , norepinephrine (inotropes) will be given as shown in fig. 1 with dose of 0.01ug/kg/min.; Patients will receive standard fluid management of 6 ml/Kg/h plus rescue fluid boluses of 200 ml lactated ringer if Mean arterial pressure (MAP) decreased less than 65 mmHg and central venous pressure less than 8 mmH2o.
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Single (Participant)
Primary purpose: Prevention