Narrative summary
A randomised controlled trial by Challand et al. (2012) compared goal directed fluid therapy using CardioQ versus
standard fluid management, in 179 patients undergoing major colorectal surgery within a fast track, enhanced
recovery programme. In the CardioQ guided fluid therapy arm, 200ml colloid boluses were given with the aim of
keeping the increase in SV below 10%; this was in addition to standard fluid therapy. In the control arm standard
fluid therapy was an infusion of crystalloid at 10ml/kg/hr, plus replacement of blood loss with blood products or
colloid. Hypotension was managed with metaraminol and vasopressor. The trial was double blinded through the
placement of a CardioQ probe in all patients and by giving sham colloid boluses to the control group (diverted to a
concealed bag). The CardioQ group received a mean of 1442 ml extra colloid than the control group; other
intraoperative fluid volumes were similar between groups. There were no statistically significant differences
between the CardioQ group and the control group for surgical readiness for discharge (6.8 versus 4.9 days
respectively, p= 0.09), total postoperative stay (8.8 versus 6.7 days respectively, p=0.09), serious postoperative
complication (10 versus 13 patients respectively, p=0.47), critical care admission (24 versus 17 patients respectively,
p=0.26) , readmission within 30 days (18 versus 13 patients respectively, p=0.35) or mortality at 30 days (2 versus 2
patients respectively, p=1) and 90 days (5 versus 4 patients respectively, p=0.72). In a subgroup of 123 aerobically fit
patients (defined by exercise test with measured anaerobic threshold > 11 ml O2/kg/min), surgical readiness for
discharge favoured the control group over the CardioQ group (4.7 days versus 7.0 days respectively, p=0.01), as did
total postoperative stay (6 days versus 8.8 days respectively, p=0.01).
Evidence table
Study
Country
Technology
Design
Study group
Sample size
Comparison
Follow up
General treatments
Challand, C., Struthers, R., Sneyd, J.R., Erasmus, P.D., Mellor, N., Hosie, K.B., & Minto, G.
2012. Randomized controlled trial of intraoperative goal-directed fluid therapy in
aerobically fit and unfit patients having major colorectal surgery British Journal of
Anaesthesia 108 (1): 53-62
UK
CardioQ
RCT
Patients undergoing major open or laproscopic colorectal surgery (excluding those too unfit
to randomise, defined by anaerobic threshold < 8 mlO2/kg/min)
179
1. Goal directed intraoperative fluid therapy (CardioQ), versus:
2. Control: standard fluid regimen
30 days
Patients were treated in a fast track, enhanced recovery programme. Patients underwent an exercise test to
determine their aerobic fitness. Aerobically fit patients were defined by anaerobic threshold > 11 ml O2/kg/min and
unfit patients by anaerobic threshold 8-10.9 ml O2/kg/min. High protein and carbohydrate drinks were given the
evening before surgery and 2-3 hours before surgery. 500-1000ml crystalloid was given to patients receiving
neuraxial blockade. Bowel preparation was discouraged but if performed, 1-2l of crystalloid was infused in the 12
hours preoperatively. A maintenance intraoperative infusion of crystalloid at 10ml/kg/hr was used. Estimated blood
loss was replaced with blood products or colloid. Arterial catheter or central venous line was used in selected
patients. Hypotension was managed with metaraminol and vasopressor. All patients received a CardioQ oesophageal
doppler probe with monitoring of SV every 15 minutes. The CardioQ screen was concealed from everyone except the
investigator.
Intervention fluid algorithm
Colloid boluses were given in response to SV as follows (reproduced from journal with permission: Copyright License
no. 3222531296503):
Comparator fluid algorithm
As ‘general treatments’, above; no strict protocol enforced. Sham boluses of colloid were administered and diverted
to a concealed bag.
Outcome measures
1. Surgical readiness for discharge (tolerating oral diet, mobilisation, self support, pain controlled with oral analgesia,
return of gut function and adequate stoma care).
2. Actual length of stay
3. Mortality
4 Readmission rates
5. Complications
Results
123 patients were defined by exercise test as aerobically fit and 56 as unfit.
Volume of intraoperative fluid administered, mean (SD)
CardioQ
Crystalloid
3489 (1088)
Colloid
311 (592)
Packed cells
97 (288)
Protocol colloid 1442 (426)
Control
3631 (1276)
262 (480)
53 (177)
-
p
0.51
0.62
0.31
-
Complications & length of hospital stay: all patients, median (IQR) / absolute number
Surgical readiness for discharge (days)
Total postoperative stay (days)
Flatus passed (days)
Bowel movement (days)
Toleration of diet (days)
Serious postoperative complication (Dindo grade 3-5)
Renal complications
Creatinine increase to >149% of baseline in first postoperative
week
Critical care admission
Readmission <30days
Mortality <30 days
Mortality <90 days
CardioQ
6.8 (4.0-9.8)
8.8 (6.011.9)
1.8 (0.9-2.9)
2.9 (1.6-4.7)
1.7 (0.8-3.0)
10
20
10
Control
4.9 (3.7-8.8)
6.7 (4.813.3)
1.8 (0.8-2.8)
2.8 (1.3-3.9)
1.8 (0.8-2.8)
13
13
6
24
18
2
5
17
13
2
4
Difference p
+1.9
0.09
+2.1
0.09
0
+0.1
-0.1
0.94
0.53
0.81
0.47
0.17
0.28
0.26
0.35
1.0
0.72
Complications & length of hospital stay: subgroup of fit patients, median (IQR) / absolute number
Surgical readiness for discharge (days)
Total postoperative stay (days)
Flatus passed (days)
Bowel movement (days)
Toleration of diet (days)
Serious postoperative complication (Dindo grade 3-5)
Critical care admission
Readmission <30days
Mortality <30 days
Mortality <90 days
CardioQ
7.0 (4.7-9.6)
8.8 (6.8-11.0)
1.5 (0.7-2.6)
2.9 (1.3-4.9)
1.7 (0.8-3.0)
6
14
11
1
2
Control
4.7 (3.0-7.8)
6.0 (4.1-9.8)
1.7 (0.7-2.8)
2.7 (0.9-3.7)
1.6 (0.7-2.8)
6
5
10
2
3
Difference
+2.3
+2.8
-0.2
+0.2
+0.1
p
0.01
0.01
0.59
0.16
0.41
0.32
0.03
0.36
0.46
0.43
Critical appraisal comments
Randomisation was double blind and stratified by aerobically fit (anaerobic threshold > 11 ml O2/kg/min) and unfit
(anaerobic threshold 8-10.9 ml O2/kg/min) subgroups. There were imbalances between the groups with respect to
operative details: more rectal and open procedures were performed in the GDT group. More epidurals were used in
the GDT group. Patients and all clinical staff but the investigators were blinded to allocation group by use of screens
to hide the CardioQ device and by use of sham boluses of colloid in control patients. A nurse recorded study
outcomes in the post operative period, blind to allocation. The sample size was based on 90% power to detect a 2
day difference in time to readiness for discharge at alpha = 0.05. A similar calculation was performed for the
subgroup of fit patients. Four patients had their allocation revealed to clinical staff: 3 due to haemorrhage and 1 due
to haemodynamic instability. Analysis was by intention-to-treat.