Netherlands Journal

netherlands journal of critical care
Table 3: Fluids in sepsis
Author/Trial name Number of patients Design Kind of fluid used renal outcome Evidence
Schortgen F. et al. 129 RCT 6% HES vs. 3% gelatine gelatine better level I
SAFE Study 6997 RCT albumin vs. saline no difference level I
Stockwell MA et al. 475 RCT albumin vs. polygeline no difference level I
Table 4: Fluids in relative hypovolemia
Author/Trial name Number of patients Design Kind of fluid used renal outcome Evidence
Sort P et al. 126 RCT albumin or no fluid better with albumin level I
Gines P et al. 105 RCT albumin or no albumin better with albumin level I
Gines A et al. 289 RCT albumin vs. dextran vs. polygeline no difference level I
Table 5: Fluids for prevention of contrast nephropathy
Author Number of patients Design Kind of fluid used renal outcome Evidence
Merten GJ et al. 119 RCT bicarbonate-containing 5% glucose (1) vs. saline (2) 1 better than 2 level II
Mueller C et al. 1620 RCT isotonic vs. half-isotonic isotonic hydration better level I
Solomon R et al. 78 RCT 0,45 % saline (1) alone vs. 1+ mannitol vs. 1 + furosemide 0,45% saline best level I
Trivedi HS et al. 53 RCT normal saline I.V. vs. deliberate oral fluid intake I.V. saline better level II
• The following endpoints were extracted:
Physiological endpoints:
- Creatinine clearance (CrCl), glomerular filtration rate (GFR),
increase in serum creatinine (∆SCr)
Clinical endpoints:
- Need for renal replacement therapy (RRT)
- Mortality
Studies were graded using the five level system described by Dellinger
and co-workers [32]. In this study, the cut-off for a large and
a small randomised controlled trial was arbitrarily set at 50 patients
per group and a meta-analysis was graded as Level I.
True hypovolaemia (surgery, trauma)
Several studies have investigated the effects of volume expansion in
hypovolaemia or expected hypovolaemia during various kinds of surgery
(Table 2). A small RCT compared lactated Ringers´ solution to
three different forms of HES in patients with normal renal function
undergoing middle ear surgery. Neither fluid was found to have any
effect on renal function [33]. The same lack of effect on renal function
was found in a large RCT comparing saline to 4% albumin [17].
Most studies compared different colloids (i.e. mainly HES vs gelatin,
albumin or dextrans)[18;34-39] without showing any particular
benefit on renal function from any of the solutions. However, a retrospective
study, reported reduced mortality in patients undergoing
coronary artery bypass surgery and receiving albumin in comparison
to synthetic colloids (level III) [40].On the other hand, in a recent
large retrospective study on 238 cardiac surgery patients, perioperative
administration of HES (670/0.75) was associated with significant
decrease of glomerular filtration rate (GFR) of an estimated magnitude
of 14 ml/min/1.73m 2 per every 2 HES units given (level III) [30].
The degree of renal impairment associated with different forms of
HES seems to be related to their molecular weight as well as to the degree
of molar substitution, although adverse renal effects have been
reported with all commercially available HES forms.
Only one study compared volume replacement versus no volume
replacement- that of Bickel and co-authors (level III) [41]. In this RCT
studying hypotensive patients with penetrating torso injuries, delay
of aggressive fluid resuscitation until operative intervention significantly
reduced mortality when compared to early volume resuscitation.
Additionally a trend towards a lower incidence of renal failure
was found in the delayed group.
Taking the existing evidence, normal saline, although it has less effect
on volume, clearly cannot be classified as inferior to colloids.
Among the colloids, it seems prudent to avoid HES, especially large
molecular weight containing HES, in patients with pre-existing renal
impairment.
Sepsis
Beneficial effects of volume replacement in sepsis have been investigated
in several trials (Table 3). In a rat model of sepsis [42] fluid
resuscitation was successful in restoring the glomerular filtration
rate if it was initiated at the moment that the bacterial inoculum was
present, but not if it was started at the moment endotoxaemia was
induced. Similar findings in humans were obtained by a prospective
study (level III)[43] which showed that in deteriorating renal function,
further fluid loading is not likely to reverse ARF in patients in
whom the septic cascade has already started. Early volume resuscitation,
however, along with other measures applied in sepsis to reach
certain targets of oxygen delivery, results in less organ failure and
reduced mortality (level I)[44]. In this study both colloids and crystalloids
were given depending on physician’s preference. Schortgen
and co-workers compared 6% HES 130/0.62 (n=65) to gelatin (n=64)
and showed lower serum creatinine levels in the group receiving gelatin
with no effect on RRT or outcome (level I)[19]. In a recent multicentre
RCT, albumin was compared to isotonic sodium chloride in
various situations including sepsis and without finding any difference
in impact on renal function (level I)[17]. A single centre RCT of
ICU patients comparing volume substitution with 5% HA or gelatin
could not find any difference in renal function despite significant differences
in serum albumin (level I) [35] . Finally, a comparison of
several forms of HES in ICU patients did not demonstrate differences
in renal function (level II) [45].
Relative or unrecognized hypovolaemia
Relative or unrecognised hypovolaemia (with respect to effective circulating
volume) are clinical situations which are often missed and
occur for example in diuretic therapy in the elderly, liver cirrhosis,
heart failure and positive pressure mechanical ventilation.
In an earlier study on the effect of diuretics on ICU patients with
renal failure, renal function recovered in about 25% of patients after
simple fluid replacement, indicating the presence of unrecognised
pre-renal failure (level III) [46]. Therefore, many authors recom-
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neth j crit care • volume 10 • no 5 • october 2006