Randomised Trial of Doppler-Optimised Fluid Balance in Elective Colectomy
Condition: Colorectal Cancer; Colectomy; Surgery; Perioperative Care
MeSH terms: Colorectal Neoplasms
Study type: Interventional
Phase: Phase 3

Summary: 
      Perioperative fluid management has been historically dictated by outdated, contradictory
      concepts. Excessive or inadequate fluid administration around surgery is deleterious and
      hence goal-directed fluid therapy using Oesophageal Doppler-derived cardiac indices is
      preferable to optimize tissue perfusion. Previous studies in this area have been hampered by
      lack of standardization in other aspects of perioperative care and none have explored the
      impact of individualized fluid therapy on post-operative fatigue.The investigators proposed a
      study involving 80 patients having open/ laparoscopic colonic surgery to investigate the
      effect of Oesophageal Doppler guided fluid administration intraoperatively compared to
      current best practice of fluid restriction. The investigators have an optimized
      peri-operative care pathway established at the Manukau Surgical Centre (MSC), Middlemore
      Hospital. All patients will be cared for under the Enhanced Recovery After Surgery (ERAS)
      multimodal care plan therefore ensuring that all other aspects of care besides intraoperative
      fluid administration remain homogenous. Outcomes will include post-operative recovery,
      clinical outcomes as well as physiological data with follow-up to 30 days.
    

Detailed description: 
      Until very recently, modern perioperative fluid management has involved routine
      administration of large quantities of fluids during major surgical procedures, typically
      causing a weight increase of 3-6 kg in the early post-operative period.Several factors,
      including concern about preoperative dehydration, attempts to support the circulation and
      cardiac function after general and regional anaesthesia, prevention of blood transfusion and
      maintenance of adequate kidney perfusion have historically lead to excess perioperative fluid
      administration.

      However administration of excess fluid has been shown to contribute to postoperative
      morbidity. It increases demand on the heart and may adversely affect postoperative cardiac
      function. It may also lead to increased pulmonary complications. Fluid overload may lead to
      oedema of the gastrointestinal tract and hence contribute to post-operative gastrointestinal
      paralysis, bacterial translocation and sepsis. Excess fluid also has been shown to decrease
      tissue oxygen tension with potential deleterious effects on anastomotic and wound healing.

      Therefore, current best practice has centred on fluid restriction peri-operatively with an
      increased focus on the intraoperative fluid regimen. Since hypovolaemia is also associated
      with a myriad of adverse outcomes, a balanced perioperative intravenous fluid regimen
      focussing on tissue perfusion is thought to be optimal. By using the Oesophageal Doppler
      Monitor (ODM) as a means to non-invasively estimate intra-operative cardiac output,
      significant improvements in outcome have been observed in patients undergoing major
      orthopaedic and cardiac procedures. Previous studies in patients undergoing major abdominal
      surgery have demonstrated that goal-directed intraoperative fluid administration using ODM
      may result in improved outcomes such as reduced number of critical care admissions, reduced
      hospital stay and overall decreased morbidity.

      In the broader context of perioperative care in colonic surgery, recent developments have
      included Enhanced Recovery After Surgery (ERAS) programmes- a combination of various
      evidence-based strategies implemented together as part of a standardised protocol to
      synergistically decrease post-operative fatigue and improve outcomes. These strategies
      include preoperative counselling, avoidance of mechanical bowel preparation, pre-operative
      carbohydrate loading, perioperative high-flow oxygen therapy, mid-thoracic epidural
      analgesia, avoidance of parenteral opioids and routine wound drainage, use of short or
      transverse incisions, early mobilisation, early feeding and a balanced analgesia regiment.
      ERAS protocols are also ideal for well-designed clinical trials as they provide a template to
      trial new interventions on the background of an otherwise homogenous, optimised perioperative
      care programme. An ERAS programme has been implemented and prospectively evaluated at Manukau
      Surgical Centre, Middlemore Hospital in Auckland.

      In a recently published systematic review, we identified that a major short-coming of the
      literature in this field is the non-standardised nature of peri-operative management of the
      patients in these studies. Although fluid management was optimised, the other aspects of care
      were not optimised or even standardised, introducing the risk of significant confounding.
      Furthermore, none have explored the role of fluid management on post-operative functional
      recovery- an important metric of patient-relevant outcomes evaluating recovery beyond
      physiological and clinical parameters. Furthermore, none of the published ERAS programmes
      have used ODM as part of their peri-operative strategies. Consequently, the true impact of
      optimised fluid therapy within an environment of current best-practice (ERAS) is unknown.

      Methods Research Design We will conduct a double-blinded, randomised controlled trial of ODM
      versus fluid restriction (current best-practice) in patients undergoing colonic surgery
      within our ERAS programme to determine whether individualising fluid administration enhances
      post-operative recovery, thereby improving patient outcomes.

      Sample Size:

      To detect a 20% improvement in recovery as measured by the Surgical recovery Score at Day 7
      (based on data from our previous work), we will require 37 patients in each arm (α= 0.05, β=
      0.8) Therefore, we shall aim to recruit 80 patients anticipating for possible drop-outs.

      Patients will be consented and then randomised by computer generated random numbers and the
      opaque envelope method. All Patients will have an oesophageal probe inserted with readings
      not available to the anaesthetist for patients in the control group (the screen will be
      covered). At the commencement of anaesthesia, the patient will be randomised to receive fluid
      management optimised by ODM data or by standard parameters. The patients, surgeons and
      investigators will be blinded to the intervention. The anaesthetists will use a validated
      protocol for the treatment group. Measurements of cardiac indices (Cardiac Output, Aortic
      Flow Rate) from the ODM will be noted intraoperatively. The Oesophageal probe shall be
      removed at the end of surgery prior to the patient waking up. All other aspects of
      perioperative care will be according to our previously developed ERAS programme.
    

Intervention name(s): Oesophageal Doppler; Intraoperative fluid restriction
Intervention type(s): Device; Procedure
Intervention description(s): Non-invasive measurement of doppler-derived cardiovascular variables (CO, aortic flow rate). Used safely over 800, 000 times; Current best practice of avoiding fluid overload by intraoperative fluid restriction
Other intervention name(s): CardioQ Deltex Oesophageal Doppler
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Doppler; Colectomy; ERAS; Fluid; Perioperative Care