Intravenous fluids in adults undergoing surgery
BMJ 2009; 338 doi: https://doi.org/10.1136/bmj.b2418 (Published 24 June 2009) Cite this as: BMJ 2009;338:b2418
All rapid responses
Liu and Finfer entitle their criticism1 of the British Consensus
Guidelines on Intravenous Fluid Therapy for Adult Surgical Patients2
“Intravenous fluids in adults undergoing surgery: high quality research is
needed before guidelines can be reliable and useful” and go on to suggest
that “perhaps guidelines should be avoided completely, and clinicians
would be better off making clinical decisions on the basis of primary
data”. They deride the guidelines as “an eclectic mixture of topics, which
seem to reflect the spheres of interest of the six specialist societies
that came together to try to establish consensus for good perioperative
fluid prescribing.” and go on to say that the covering of preoperative,
intraoperative and postoperative management and the inclusion of topics
such as mechanical bowel preparation, nutrition, and fluid management in
acute kidney injury adds complexity rather than clarity”.
While we trust Liu and Finfer appreciate that perioperative fluid
therapy in the real world is complex and multidisciplinary (hence the
involvement of six specialist societies), we feel that their review
largely missed the point of the guidelines, which was to provide a
synthesis of the available evidence that would support safe practice in an
“orphan” area of clinical care, notorious for being poorly practiced and
badly taught3, 4.
Liu and Finfer accuse us of shying away from “a systematic evidence
based approach because high quality evidence is lack¬ing”. We were of
course, necessarily constrained by the evidence that exists and developed
our guidelines according to internationally recognized criteria. A glance
at our reference list might have reassured them that we considered and
included the results of many systematic reviews, including those related
to preoperative fasting, mechanical bowel preparation, oesophageal doppler
monitoring, choice of fluid (crystalloids versus colloids), enhanced
recovery programmes, as well as NICE guidance on surgical and nutritional
management, which are themselves based on multiple, often new, meta-
analyses. In this context it is surprising that they single out for
criticism the recommendation on the use of dopexamine which was supported
by both meta-analysis and systematic review5. The references they quote
against this recommendation did not test dopexamine.
Systematic reviews and meta-analyses have a vital role in the
assessment of evidence, but by their nature must be focused on specific,
usually robustly defined questions. They, therefore, represent an
examination of selected aspects of treatment. Consensus guidelines such as
ours on the other hand have a broader remit and serve an entirely
different purpose. They try to synthesise the jigsaw of evidence into a
coherent view of overall clinical policy.
Liu and Fifner wrongly assume that the myriad of clinically relevant
issues that make up safe and effective perioperative fluid therapy can be
reduced to a series of limited questions for which a clinical evidence
base might be found. What realistic question could possibly be asked which
would enable a systematic review of all the different components which
contribute to outcome over the whole of perioperative fluid management
covered in our consensus document?
Patients have to be treated now, not at some hypothetical time when
every aspect of their care has been subjected to perfect double blind
randomized clinical trials or systematic reviews. Indeed, many aspects of
overall care can never be subjected to practical or ethical controlled
trials. Clinicians have ultimately to weigh the evidence that exists,
construct a logical approach, and teach their juniors coherently and as
best they can. To expect every clinician to be aware of the primary
sources to which Liu and Finfer so academically prefer to return, every
time they see a patient is patently absurd. To expect them to weigh these
references according to an internationally recognised system for evidence
scoring, and then discuss the detail of each of these papers with expert
colleagues from five other disciplines is equally unrealistic. The value
of the guidelines, which have since been endorsed and adopted by The Royal
College of Anaesthetists is that we have done precisely that for them.
Liu and Finfer evidently disapprove of eclecticism which means
deriving ideas, style, or taste from a broad and diverse range of sources.
We do not. The fluid status of surgical patients is affected by individual
factors such as bowel preparation, anaesthetic technique, postoperative
analgesia and nutrition as well as the choice and quantity of intravenous
infusions. A complete and effective clinical view therefore requires a
patient-centred approach which is thus necessarily eclectic.
We fully accept that no set of guidelines are perfect and it is entirely
appropriate that they should be scrutinised and critically discussed. We
are also aware that many clinicians will eschew guidelines as a matter of
principle, while others may reject the Oxford system for weighing
evidence. There will clearly be dissent over individual recommendations.
We think, however, that it is unusual in medicine to be able to secure
consensus on behalf of no less than six national societies. By producing
them we have forced ourselves to consider where we stand practically and
clinically rather than in the isolated compartments of the problem. We
think this is a discipline others too should be bold enough to consider.
The guidelines will be revised in due course as new evidence emerges, and
will no doubt improve with the quality of the clinical evidence that
informs them. Liu and Finfer’s comments should be interpreted with caution
lest the baby gets thrown out with the bathwater and we end up unable to
move forward in an area of poor clinical practice.
Jeremy Powell-Tuck, Peter Gosling, Dileep N Lobo, Simon P Allison,
Gordon L Carlson, Marcus Gore, Andrew J Lewington, Rupert M Pearse, Monty
G Mythen
References
1. Liu B, Finfer S. Intravenous fluids in adults undergoing surgery.
BMJ 2009;338: b2418.
2. Powell-Tuck J, Gosling P, Lobo DN, Allison SP, Carlson GL, Gore M, et
al. British Consensus Guidelines on Intravenous Fluid Therapy for Adult
Surgical Patients - GIFTASUP. 2008. Available from:
http://www.ics.ac.uk/downloads/2008112340_GIFTASUP%20FINAL_31-10-08.pdf
(Accessed 12 July 2009).
3. Lobo DN, Dube MG, Neal KR, Simpson J, Rowlands BJ, Allison SP. Problems
with solutions: drowning in the brine of an inadequate knowledge base.
Clin Nutr 2001;20: 125-130.
4. Herrod P. The importance of fluid and electrolyte management--a medical
student's perspective. Clin Nutr 2009;28: 218.
5. Pearse RM, Belsey JD, Cole JN, Bennett ED. Effect of dopexamine
infusion on mortality following major surgery: individual patient data
meta-regression analysis of published clinical trials. Crit Care Med
2008;36: 1323-1329.
Competing interests:
The authors have reviewed the literature and have written the GIFTASUP document.
Competing interests: No competing interests
The editorial comment on the BAPEN guidelines for intravenous fluids
in
adults undergoing surgery by Liu and Finfer has the potential to harm
patients.
Firstly, the authors make the common mistake of quoting the papers by
Hayes and Gattinoni to argue the case against protocols that use fluids
and
inotropes to elevate oxygen delivery in surgical patients. These papers,
however, studied critically ill patients, in whom the inflammatory process
and
mutli-organ failure sequence was already firmly established, and have
little
relevance to the general high-risk surgical population.
Secondly, and more importantly, the authors' advice that clinicians
would be
better off making clinical decisions on the basis of primary data -
whatever
that is - could definitely lead to harm. Our study of pre-operative
optimisation of oxygen delivery in high-risk surgical patients was
essentially
a comparison of fluid therapy determined by clinical judgement with fluid
therapy titrated to specific haemodynamic goals[1]. The mortality rate in
the
clinical judgement group - the approach advocated by Liu and Finfer - was
17%, compared to 3% in the goal-directed therapy groups.
To ignore the evidence from the appropriate trials, to then argue
against
recommendations from guidelines on the strength of inappropriate trials,
and then finally to recommend treatment by clinical judgement alone are
misleading and harmful strategies.
I accept the need for further research, and am active in that area,
but in the
meantime, as a practising clinician, I will not throw away the recent
advances
in intravenous fluid therapy and peri-operative care to satisfy the
requirements of the evidence-based medicine purists.
1. Wilson J, Woods I, Fawcett J et al. Reducing the risks of major
elective
surgery: randomised controlled trial of preoperative optimisation of
oxygen
delivery. BMJ 1999; 318:1099-1103.
Competing interests:
I have received an honorarium
from Fresenius Kabi for lecturing
on goal-directed fluid therapy.
Competing interests: No competing interests
If everything one did was evidence-based, one would have little to
do. So let's be grateful that these people have taken it upon themslves to
produce this work.
Of course, the recommendations are imperfect but those that perceive
such imperfection do so through their own biases and opinions. As an
Emergency Physician I could, for instance, rant about the fact that shock-
ultrasound is overlooked. I also find the administeration of 200ml boluses
in a shocked adult overly cautious, especially when a CVP line is in
place. But I rise above such negativity when I encounter boldness and
effort.
These guidelines are a great start and a laudable attempt to wrap-up
the current state of play. It is from work like this that trainees will
identify areas for further focused research. And that's where the revised
guidleines will come from.
Competing interests:
None declared
Competing interests: No competing interests
Intravenous fluids in adults surgical patients - A fluid concept?
We welcome Liu and Finfer’s editorial opinion as it reopens the
debate regarding this topic. The British Consensus Guidelines highlighted
several important areas of clinical practice in the care of adult surgical
patients.
We agree with the editorial’s comments that these guidelines were not
generated based on rigorous evidence based methodologies. As such its
clinical application may be limited and clinicians choosing to ignore them
may easily justify their actions.
In the era of evidence based practice, consensus opinion based on sub
-optimal evidence should serve as a platform for hypothesis generation
rather than gospels for best practice. This lack of high level evidence on
fluid management in surgical patients identifies a potential area for
surgical research and the urgent need for funding.
Further, while teaching on the fluid management in surgical patients
has largely remained unchanged in the last two decades, the patient
profiles have evolved dramatically. In the UK, NHS trusts now treat the
majority of their surgical cases as day cases. Those who require in-
patient peri-operative care are in general older, with more co-morbidity
or undergoing major surgery. Thus it is high time for closer scrutiny of
our approach to fluid management in order to adapt to the fluidity of this
increasingly dynamic cohort.
The editorial’s opinion on the shortcomings of this consensus
guideline should not be taken as mere criticism, but rather echoing the
importance of prioritised funding to attract high quality research to
inform and perhaps reshape our future surgical practice.
Competing interests:
None declared
Competing interests: No competing interests