2002 [33]Elective bowel surgery57 in two groupsNo blinding.
Near maximal stroke volume EDM (CardiQ^®)LOSHES 6%Not givenColl: 28 ml/kg (GDT) vs. 19 ml/kg
Total 64 ml/kg (GDT) vs. 55 ml/kgNot givenNo differences for LOS or morbidity.
Mortality: 0 (GDT) vs. 1Gan et al.
2002 [34]Elective general, urological or gynecological100 in two groupsNo blinding.
Near maximal stroke volume, EDM (CardiQ^®)LOSHES 6%Not givenColl: 847 (GDT) vs. 282
Cryst: 4,405 (GDT) vs. 4375Not givenGDT reduced LOS.
No difference for morbidity.
Mortality not reportedWakeling et al. 2005 [35]Elective colorectal resection128 in two groupsObserver blinded.
Near maximal stroke volume EDM (CardiQ^®)LOSHaemaccel^® or Gelofusine^®1,000–2,000 Hartmann’s solution from midnightMedian coll: 2,000 (GDT) vs. 1,500.
Cryst: 3,000 both groupsEarly oral intake, fluid volumes not given (i.v. or oral)GDT reduced LOS and morbidity.
Zero mortalities in 30 days, 1 (control) after 60 daysNoblett et al. 2006 [36]Elective colorectal resection108 in two groupsObserver blinded.
Near maximal stroke volume EDM (CardiQ^®)LOSVolplex^®Not givenColl: 1,340 (GDT) vs. 1,209
Cryst: 2,298 (GDT) vs. 2,625Early oral intake, fluid volumes not given (i.v. or oral)GDT reduced LOS and morbidity.
Mortality: 0 (GDT) vs. 1 (control)Lopes et al. 2007 [37]Elective mixed GI and urological33 in two groupsNo blinding.
Pulse pressure variation (PPV)LOSHES 6%Not givenColl: 2,247 (GDT) vs. 0
Cryst: 2,176 (GDT) vs. 1,563Patients transferred to ICU; fluid or other treatment not givenGDT reduced LOS and morbidity.
Mortality: 2 (GDT) vs. 5 (followed until discharge)Buettner et al. 2008 [38]Elective general, urological or gynecological80 in two groupsNot blinded.
Stroke volume variation (PiCCOplus^®)ScvO₂ and serum lactateHES 6% (Voluven^®)Not givenColl: 1,500 (GDT) vs. 1,000.
Cryst: 4,500 (GDT) vs. 4,250Not givenNo difference in ScvO₂ or lactate
Mortality: 1 patient in control group “after several weeks.” “All others discharged from ICU alive”Forget et al. 2010 [39]Elective mixed GI surgery82 in two groupsObserver blinded.
Pleth variability index (PVI)Whole blood lactate levelsHES 6% (Voluven^®)Not givenColl: 890 (GDT) vs. 1,003
Cryst: 1,363 (GDT) vs. 1,81524 h postop.
Col: 268 (GDT) vs. 358. Cryst: 3,107 (GDT) vs. 3,516GDT reduced lactate levels.
No difference in morbidity.
Mortality: 2 (GDT) vs. 0Mayer et al. 2010 [40]Elective mixed GI surgery60 in two groupsObserver blinded.
Stroke volume variation (SVV) (FloTrac^®)LOSNot given, just “colloid”Not givenColl: 1,180 (GDT) vs. 817
Cryst: 2,489 (GDT) vs. 3,153Not givenGDT reduced LOS and morbidity.
Mortality: 2 in each groupBenes et al. 2010 [41]Elective mixed GI and vascular surgery120 in two groupsObserver blinded.
Stroke volume variation (SVV) (FloTrac^®)Postop complicationsHES 6% (Voluven^®)Not givenColl: 1,425 (GDT) vs. 1,000
Cryst: 2,321 (GDT) vs. 2,4598 h postop:
Col: 0 vs. 0
Cryst: 1,587 (GDT) vs. 1,528GDT reduced morbidity and LOS.
Mortality: 1 (GDT) vs. 2Challand et al. 2012 [42]Elective open or laparoscopic colorectal surgery236 in four groups: fit vs. unfit and GDT vs. standardObserver blinded.
Near maximal stroke volume EDM (CardiQ^®)LOSHES 6% (Voluven^®)1,273 (GDT) vs. 971 Hartmann’s solutionColl: 358 (GDT) vs. 336
Cryst: 3,479 (GDT) vs. 3,5931. postop. day:
2,083 (GDT) vs. 2,011GDT worsened LOS and morbidity for the fit. No difference for the unfit.
Mortality 30 days: 2 vs. 2.
90 days: 5 (GDT) vs. 4Salzwedel et al. 2013 [43]Elective general, urological, or gynecological160 in two groupsPatient blinded.
Pulse pressure variation (PPV) and CI monitoringPostop. complicationsNot givenNot givenColl: 774 (GDT) vs. 725
Cryst: 2,862 (GDT) vs. 2,68024 h postop.
Coll: 57 (GDT) vs. 147. Cryst: 3,204 (GDT) vs. 3,452GDT reduced complications but not LOS.
Mortality: not given

Fluid volumes are in ml.

LOS, length of stay; EDM, esophageal Doppler monitoring; CI, cardiac index; HES, hydroxyethyl starch; GI, gastrointestinal.

NOTE: One reference was excluded from the table because inclusion and exclusion criteria were unclear.[44]

An interesting feature is that the increase in stroke volume was achieved with a colloid solution while at the same time all the patients, regardless of the stroke volume measurements, received large amounts of crystalloid. This may have two interpretations: either the crystalloid is given as pure fluid overload and leaves the circulation almost immediately (as crystalloid fluid does when given to normovolemic persons), or crystalloid cannot raise stroke volume significantly.

Most of the trials have in common that the patient sample is small, and the trials are powered to show a difference in length of hospital stay, but also that the GDT intervention in most cases improved the outcome relative to standard fluid therapy. It is interesting that colloid including hydroxyethyl starch (Voluven) apparently has beneficial effects on outcome in elective bowel surgery, and not the side effects seen in a population of septic patients.[27] Recently the so-called “restricted fluid therapy approach” (zero fluid balance) has been tested against GDT without the fluid overload with crystalloid (GDT on a zero balance basis) (Table 21.2).

Table 21.2 Trials of “goal-directed fluid therapy” (GDT) versus “restricted fluid therapy” in abdominal surgery

Author	Surgery	No. of patients	Blinding and intervention	Primary outcome	Intervention fluid	Preoperative fluid volume	Intraoperative fluid volume	Postoperative fluid volume	Results
Brandstrup et al. 2012 [45]	Elective laparoscopic or open colectomy	150 in two groups: GDT vs. “restricted”	Observer blinded. Near maximal stroke volume (EDM) (CardiQ®)	Patients with postop. complications	HES 6% (Voluven^®)	2 h fasting for fluid. 500 ml saline if no fluid in 6 h	Coll: 810 (GDT) vs. 475 Total volume 1,877 (GDT) vs. 1,491 (restricted)	Oral fluid in an enhanced recovery protocol. i.v. fluid if oliguria, tachycardia, or hypotension	No difference in morbidity or LOS. Mortality: 1 in each group
Zhang et al. 2012 [46]	Elective open GI surgery	60 in three groups: 4 ml/(kg h) and GDT-Ringer’s; 4 ml/(kg h) and GDT-HES; and 4 ml/(kg h) Ringer’s	Observer blinded. Pulse pressure variation (PPV)	LOS	Ringer’s lactate and HES 6%	Not given	Total volume: GDT-Ringer’s: 2,109 vs. GDT-colloid: 1,742 vs. restricted Ringer’s 1,260	1.5–2.0 ml/(kg h) crystalloid for 3 days. Oral intake not mentioned	LOS was shortest in GDT-colloid group, longest in the GDT-Ringer’s group. Morbidity: no difference. Mortality: none
Srinivasa et al. 2013 [47]	Elective laparoscopic or open colectomy	85 in two groups GDT vs. “restricted”	Observer blinded. Near maximal stroke volume (EDM) (CardiQ®)	Surgical Recovery Score (SRS)	Succinylated gelatin colloid solution Gelofusine	13 patients with bowel preparation: 1,000 ml crystalloid	Coll: 591 (GDT) vs. 297 Total volume: 1,997 (GDT) vs. 1,614 (restricted)	Oral fluid in an enhanced recovery protocol. i.v. fluid if oliguria, tachycardia, or hypotension	No difference in SRS, LOS, or postoperative morbidity. Mortality: none
Phan et al. 2014 [48]	Elective colorectal surgery	100 in two groups GDT vs. “restricted”	Near maximal stroke volume (EDM) (CardiQ^®)	LOS			Total volume 2,115 (GDT) vs. 1,500 (restricted)	Oral fluid in an enhanced recovery protocol	No difference in LOS or postoperative morbidity Mortality: none

LOS, length of stay; EDM, esophageal Doppler monitoring. Fluid volumes are in ml.

The two regimens have shown an equally good outcome for the patients. However, all clinical randomized trials of fluid therapy in general have weaknesses. Firstly, it is very difficult to blind randomized clinical trials of fluid therapy. The fluids cause changes in the patient’s body weight and in the urinary output, and if more than 20% of the extracellular fluid volume is given (≥3 liters for a 75 kg person), a visible subcutaneous edema is formed. The latter means that only trials with a fluid difference less than 3 liters between groups are possible to blind effectively.

Secondly, one has to be very careful in the choice of endpoints. Length of stay (LOS) has especial problems. The introduction of fast-track surgery has illustrated that the most important factor for LOS is expectations from patients as well as the doctors. They simply stay in hospital as long as everybody expects them to. Other important factors are traditions including the use of drains, the allowance of the patient to return to oral food, and the type of analgesia used postoperatively.

Thirdly, in all research concerning surgical patients, the many confounders are at best difficult- to control. This is especially a problem for trials including a small number of patients. Large numbers of patients will equalize the confounders between the groups compared. For example, postoperative nausea and vomiting (PONV) is highly influenced by the fact that opiates have pronounced PONV side effects.

Intraoperative fluid therapy in outpatient surgery

The trials of different fluid volumes during outpatient and minor abdominal surgery are shown in Table 21.3.

Table 21.3 Trials of outpatient abdominal surgery

Author	Surgery	No. of patients	Blinding	Duration of surgery	Intervention	Fast	Postop. oral fluid intake	Results
Keane & Murray 1986 [49]	Mixed outpatient surgery	212 in 2 groups	No	18 min	1,000 ml Hartmann’s solution + 1,000 ml DW vs. No fluid	?	?	Fluid reduces thirst and drowsiness, and increases well-being. No effect on nausea
Spencer 1988 [50]	Minor gynecological surgery	100 in 2 groups	No	8 min	1,000 ml CSL vs. No fluid	?	?	Fluid reduces dizziness and nausea
Cook et al. 1990 [51]	Gynecological laparoscopy	75 in 3 groups	Yes	20 min	CSL 20 ml/kg vs. CSL + DW 20 ml/kg vs. No fluid	11–16 h	?	Fluid reduces dizziness and drowsiness. Hospital stay reduced in dextrose group
Yogendran et al. 1995 [52]	Mixed outpatient surgery	200 in 2 groups	Yes	28 min	Plasma-Lyte 20 ml/kg (1,215 ml) vs. Plasma-Lyte 2 ml/kg (164 ml)	8–13 h	?	Fluid reduces thirst, dizziness and drowsiness. No effect on nausea
McCaul et al. 2003 [53]	Gynecological laparoscopy	108 in 3 groups	Yes	22 min	CSL 1.5 ml/kg per fasting hour (1,115 ml) vs. CSL + DW 1.5 ml/kg per fasting hour (1,148 ml) vs. No fluid	11.5 h	?	No significant differences between the groups
Magner et al. 2004 [54]	Gynecological laparoscopy	141 in 2 groups	Yes	20 min	CSL 30 ml/kg vs. CSL 10 ml/kg	13 h	?	Fluid reduced nausea and vomiting. No effect on dizziness or thirst
Holte et al. 2004 [29]	Laparoscopic cholecystectomy	48 in 2 groups	Yes	68 min	LR 15 ml/kg (998 ml) vs. 40 ml/kg (2,928 ml)	2 h	Mean 600 ml	Fluid reduces thirst, nausea, dizziness, drowsiness; improves well-being and pulmonary function; and shortens hospital stay

DW, dextrose in water 5%; CSL, compound sodium lactose (Na:131, K:5, Ca:2, Cl:111, lactate:29 mmol/l); LR, lactated Ringer’s solution.

These trials have shown that approximately 1 liter of fluid i.v. causes better postoperative well-being (less PONV) in patients undergoing outpatient surgery. This finding seems logical because patients undergoing outpatient surgery are told to fast from midnight before surgery, i.e. they have a fluid deficit of approximately 1 liter.[28]

A surprising finding was that by Holte et al. [29] who examined the effect of 3 liters versus 1 liter of fluid on PONV, postoperative ability to run on a treadmill, and pulmonary function measured by spirometry. The trial showed that patients receiving 3 liters had less PONV and better exercise performance than the patients given 1 liter. This trial has, however, a problem with the doses of postoperative opiates, with smaller doses given to the patients in the group given most fluid.

Only gold members can continue reading. Log In or Register to continue