Anaesthesia and Intensive Care

Anaesthesia and Intensive Care

There is continued controversy regarding the benefits of goal-directed fluid therapy (GDT) which requires the use of a cardiac output monitor such as the oesophageal Doppler monitor. Previous evid- ence of improved outcome from GDT in colorectal surgery led to a recommendation from national bodies in the United Kingdom and United States to endorse Doppler-guided GDT as a standard of care in major abdominal surgery, including colectomies1. Its use has also been supported within an Enhanced

Recovery After Surgery (ERAS) program for colonic resection2. However, these earlier studies did not compare GDT directly with fluid restriction, which had also shown improvements in patient outcomes3–5. Recently, two studies have compared fluid restriction to GDT in major colorectal surgery and found no significant difference in outcome between the two techniques6,7. However, there is a much larger body of work supporting GDT, with a total of 32 studies and 2808 patients in a recent review, which found a reduction in mortality and morbidity in high-risk surgery and in morbidity alone in low-risk surgery (identified as a mortality rate <5%)8. There is also a spectrum of GDT protocols with some using fluid therapy alone as the intervention, while others use fluid and inotropes, such as dopexamine, to achieve an oxygen delivery target. Given that both approaches led to a reduction in complication rates in a recent review8, a Doppler-guided, fluid-only Anaesthesia and Intensive Care

* MB BS, FRCA, FANZCA, Staff Specialist Anaesthetist † MB BS, FRACS, Surgical Fellow, Department of Colorectal Surgery, St

Vincent’s Hospital, Fitzroy, Victoria ‡ BMed, Anaesthetic Fellow § MB BS, FRACS, Visiting Medical Officer, Department of Colorectal

Surgery, St Vincent’s Hospital, Melbourne, Victoria ** MB BS, FANZCA, Staff Specialist Anaesthetist

Address for correspondence: Dr Tuong D. Phan. Email: tuong.phan@ svha.org.au

Accepted for publication on September 2, 2014 Anaesthesia and Intensive Care

A randomised controlled trial of fluid restriction compared to oesophageal Doppler-guided goal-directed fluid therapy in elective major colorectal surgery within an Enhanced Recovery After Surgery program T. D. PHAN*, V. AN†, B. D’SOUZA†, M. J. RATTRAY‡, M. J. JOHNSTON§, B. S. COWIE** Department of Anaesthesia, University of Melbourne, St Vincent’s Hospital, Melbourne, Victoria

SUMMARY There is continued controversy regarding the benefits of goal-directed fluid therapy, with earlier studies showing marked improvement in morbidity and length-of-stay that have not been replicated more recently. The aim of this study was to compare patient outcomes in elective colorectal surgery patients having goal- directed versus restrictive fluid therapy. Inclusion criteria included suitability for an Enhanced Recovery After Surgery care pathway and patients with an American Society of Anesthesiologists Physical Status score of 1 to 3. Patients were intraoperatively randomised to either restrictive or Doppler-guided goal-directed fluid therapy. The primary outcome was length-of-stay; secondary outcomes included complication rate, change in haemodynamic variables and fluid volumes. One hundred patients, 50 in each group, were included in the analysis. Compared to restrictive therapy, goal-directed therapy resulted in a greater volume of intraoperative fluid, 2115 (interquartile range 1350 to 2560) ml versus 1500 (1200 to 2000) ml, P=0.008, and was associated with an increase in Doppler-derived stroke volume index from beginning to end of surgery, 43.7 (16.3) to 54.2 (21.1) ml/m2, P <0.001, in the latter group. Length-of- stay was similar, , P=0.421. The number of patients with any complication (minor or major) was similar; 60% (30) versus 52% (26), P=0.42, or major complications, 1 (2%) versus 4 (8%), P=0.36, respectively. The increased perioperative fluid volumes and increased stroke volumes at the end of surgery in patients receiving goal-directed therapy did not translate to a significant difference in length-of-stay and we did not observe a difference in the number of patients experiencing minor or major complications. Anaesthesia and Intensive Care

Key Words: fluid therapy, cardiac output, Doppler, colorectal surgery, postoperative complications, monitoring – intra- operative

Anaesth Intensive Care 2014; 42: 752–760

753FLUID RESTRICTION COMPARED TO DOPPLER-GUIDED THERAPY

Anaesthesia and Intensive Care, Vol. 42, No. 6, November 2014

algorithm would be more practical within an ERAS framework where the use of inotropes requiring central lines and critical care admissions would not be practical. The aim of our study thus was to compare outcomes in elective colorectal surgery between patients having restrictive versus Doppler- guided GDT.

MATERIALS AND METHODS This was a prospective blinded study at the St Anaesthesia and Intensive Care

Vincent’s Hospital campus, St Vincent’s Public Hospital and St Vincent’s Private Hospital, Fitzroy, Victoria. The study had institutional ethics approval (no. 039/12) and was registered with the Australia and New Zealand Clinical Trials Registry, ACTRN12612000717853.

Enrolment All patients undergoing major colorectal surgery

and enrolled in the local ERAS care pathway were screened for eligibility.

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Exclusion criteria included American Society of Anesthesiologists Physical Status 4, pregnancy, in- ability to give informed consent, emergency surgery, significant renal dysfunction (estimated glomerular filtration rate <50 ml/minute), hepatic dysfunction, severe heart failure (New York Heart Association classification 3 or 4), age <18 years and oesophageal pathology (such as varices), which is a relative contraindication to an oesophageal probe. Anaesthesia and Intensive Care

Randomisation with sealed opaque envelopes was through a computer-generated randomisation sequence and occurred on the day of surgery just prior to the anaesthetic. Randomisation was stratified to either stoma or non-stomal pathway to ensure equal numbers in each group. Colorectal resections that require a stoma have a separate ERAS pathway

to allow for patient education about stomal care. In addition, stomas are more frequently utilised in lower rectal resections which are associated with increased length-of-stay (LOS) and have a higher anastomosis leakage rate9,10. The anaesthetist was not blinded. However, the patient, surgical team and data collectors were. Anaesthesia and Intensive Care

The patients followed an ERAS clinical care pathway. Patients did not have routine nasogastric tube insertion. Oral fluids were encouraged four hours post-surgery and oral diet commenced from day one. Discharge criteria included resumption of normal diet without nausea or vomiting, return of bowel function, ability to self-care and mobilise independently or be able to be cared for and mobilised by pre-existing care arrangements. Pain needed to be adequately controlled with oral analgesics.

Treatment All patients had a general anaesthetic technique with

muscle relaxant. This consisted of a balanced anaesthetic induction including midazolam, a short acting opioid, propofol and a muscle relaxant. Maintenance was with an inhalational agent (sevoflurane or desflurane). Total intravenous anaesthesia was used if indicated. Epidural analgesia was utilised for planned open surgery if there were no contrain- dications. Transversus abdominal plane blocks were also utilised where appropriate. Intraoperatively, all patients were given intravenous paracetamol and parecoxib unless there was a contraindication. The postoperative analgesia protocol consisted of regular paracetamol, non-steroidal anti-inflammatory drugs and opioid patient-controlled analgesia. Anaesthesia and Intensive Care

Fluid therapy followed a strict protocol with the restrictive group receiving a set maintenance rate (Table 1). The oesophageal Doppler monitor (ODM) was not used in this group. Previous work has already

Table 1 Fluid protocol for restrictive and Doppler-guided fluid therapy in colorectal patients

Restrictive Doppler-guided

Preoperative Nutricia PreOp* 2 x 200 ml carbohydrate drink (the day before surgery and 2 hrs before surgery)

Nutricia PreOp* 2 x 200 ml carbohydrate drink (the day before surgery and 2 hrs before surgery)

Intraoperative Anaesthesia and Intensive Care

Preload 0 0

Post induction bolus Up to 5 ml/kg Hartmann’s solution Up to 5 ml/kg Hartmann’s solution

Maintenance 5 ml/kg/hr Hartmann’s solution 5 ml/kg/hr Hartmann’s solution

Boluses Only to replace blood loss or hypotension not responsive to vasopressor

Doppler GDT algorithm with colloid boluses

Postoperative (maintenance) 0.5 ml/kg/hr Hartmann’s solution (with a minimum of 40 ml/hr)

0.5 ml/kg/hr Hartmann’s solution (with a minimum of 40 ml/hr)

*Nutricia, West Ryde, NSW. GDT=goal-directed therapy.

754 T. D. PHAN ET AL

Anaesthesia and Intensive Care, Vol. 42, No. 6, November 2014

established that GDT using ODM results in improved stroke volume (SV) and a reduction in corrected flow time compared to a restrictive fluid policy6,7. The GDT group had a similar protocol except during the time of the intraoperative intervention an ODM was utilised to facilitate targeting colloid boluses to fluid responsiveness as indicated by a change in SV index (SVI) >10% and a corrected flow time interval of <350 milliseconds11. Anaesthetists in the intervention group were asked to adhere to the SV optimisation algorithm (Figure 1), which stipulates the admin- istration of a 250 ml bolus of a colloid, although the colloid type was at the discretion of the anaesthetist. This was due to a lack of evidence of efficacy of one type of fluid over another12, although colloids were encouraged as they generally result in greater intravascular expansion13. Crystalloid Hartmann’s solution was used for maintenance. Colloid boluses were starch colloids (4% hydroxyethyl starch, Voluven® or Volulyte® [Fresenius Kabi Pty Ltd, Bad Homburg vor der Höhe, Hesse, Germany] 180/0.3), 4% Gelofusine® (B. Braun, Melsungen, Germany) or 4% human serum albumin. In July 2013, starch colloids were removed from general use at our institution due to safety alerts Anaesthesia and Intensive Care

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