Abstract
Inappropriate fluid regimens are rarely documented as being responsible for patient harm, although there is considerable circumstantial evidence to suggest that fluid overload may be a considerably under-estimated source of patient morbidity and mortality. The GIFTASUP fluid management guidelines published in 2008 offer a valuable opportunity to consider a more standardised approach to fluid management, possibly in the context of developing routine hospital services to support good practice.
Few areas of medicine could compete with intravenous fluid therapy for the title of the quintessential cross-disciplinary subject. The clinical situations in which intravenous fluids of one form or another are used are myriad, as is the range of physiological, clinical and biochemical parameters that potentially contribute to their use and monitoring. The British Consensus Guidelines on Intravenous Fluid Therapy for Adult SUrgical Patients (GIFTASUP) 1 are a much needed and robust attempt to classify the different medical and surgical situations involved, grade the evidence and produce clear didactic guidelines on fluid management. Not everyone will agree with every recommendation, but unlike the less directly interventional area of laboratory diagnostics, the group has identified a large volume of high level evidence to support most of its recommendations.
To put the subject in context, the guidelines begin with some data extracted from a review written by Arieff in 19992 using 1993 data from two American university teaching hospitals, which attempted to estimate the burden of morbidity and mortality from pulmonary oedema in patients following major surgery. After subtracting other co-morbidities to explain the oedema (myocardial infarction, pulmonary embolus, hyponatraemia (<130 mmol/L), acute renal failure, gastrointestinal bleed or stroke), Arieff estimated that there could be 213,200 cases of postoperative pulmonary oedema annually in the United States, accounting for 8315 deaths during the 30 days following surgery, in which no cause apart from excessive fluid administration could be inferred. When the additional co-morbid conditions were included, the figures rose to 74,000 and 622,000 respectively. These American figures probably represent a conservative estimate of the actual burden of illness caused by intravenous fluids when one considers that they only include deaths or episodes of pulmonary oedema and not morbidity which may ultimately result in prolonged hospitalizations or post 30-day deaths. Subtracting those patients who had other potential explanations for pulmonary oedema also produces a very conservative estimate as these are among the very people likely to suffer most from inadequate fluid management. They also relate only to the postoperative situation and exclude the large number of especially frail elderly medical patients with or without hyponatraemia, who are particularly vulnerable to the effects of fluid overload. The figures for all hospital patients combined are probably therefore several times higher.
Although there are huge limitations in applying extrapolated American data for 1993 to the UK situation in 2009, a simplistic extrapolation to the UK based just on the respective populations of the two countries would suggest that the problem could be of the same order of magnitude as morbidity and mortality from road traffic accidents (2946 fatalities and 27,774 serious injuries in the UK reported in the in 2007 Road Casualties Great Britain Annual Report). 3
The guidelines also highlight a number of explanatory causes based on a number of published, albeit relatively small, surveys and audits
4–7
that highlighted the following:
Variable approaches to fluid management by consultant clinical staff; Frequent delegation of fluid management to very junior medical staff; Limited training and knowledge of junior medical staff.
To this can be added the inadequate availability and distribution of appropriate clinical knowledge, most eloquently summarized in the title of one of the reports: ‘Problems with solutions: drowning in the brine of an inadequate knowledge base’.
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The decreasing continuity of care following implementation of the European Working Time Directive on junior doctors' hours is only liable to worsen this situation.
Intravenous fluid management suffers more severely from some of these problems because it does not fall within a single medical discipline. Fluid and electrolyte balance was commonly taught routinely as part of clinical biochemistry to medical students although a number of authors including Freedman 8 have recently highlighted the limitations of modern medical education because of the number of specialties vying for position in the curriculum. Within clinical biochemistry the emphasis tended to be more on physiological explanation of electrolyte changes rather than the more practical issue of specifically which replacement solutions, volumes and additions to use in different clinical situations. Although fluid management forms part of almost all medical and surgical specialties, much of the teaching emphasis and indeed medical students' interests lie in the medical and surgical diagnoses and treatment rather than what might often be seen as ‘housekeeping’. This is what makes the British Consensus guidelines so important and such a valuable addition to the knowledge base.
Despite the fact that intravenous fluids are among the most commonly used and potentially the most dangerous ‘medicines’, particularly in frail older patients with multiple illnesses, they pass by almost unnoticed in some of the incident reporting systems. A search of the National Patients' Safety Agency website (
The challenge that faces us now is how to secure implementation of the recommendations in these guidelines and use the rationale behind the recommendations to improve the knowledge of those who prescribe and monitor intravenous fluids. This, by necessity, requires a multidisciplinary approach and it is encouraging to see the range of organizations that have contributed to the writing of these guidelines.
There are a number of ways of improving the situation.
Firstly, we could continue efforts to emphasize the need for more specific training for medical students around fluid and electrolyte balance. This continues a theme that appears recurrently about the importance of bringing diagnostics and laboratory medicine back into a more central position in the medical curriculum. This will only be achieved once greater recognition is awarded to the importance of the role of laboratory diagnostics in overall patient management.
Secondly, foundation doctors' training should incorporate more collaborative teaching from biochemists and clinicians about fluid and electrolyte abnormalities, supported by more innovative means of professional development, perhaps using the guidelines as the basis to construct educational modules to backup on-site teaching.
This is part of the more general problem of converting existing guidance documents, some of which may run to several hundred pages, into clinical tools for ward and consulting room use.
Thirdly, should clinical biochemists be re-examining their clinical roles beyond metabolic medicine into a more proactive involvement in fluid and electrolyte management? While hospitals that routinely house larger numbers of patients receiving total parenteral nutrition may have dedicated nutrition teams visiting patients and reviewing their results, it is difficult to imagine a consultant in a large hospital being able to review every individual patient's fluid and electrolyte charts. It is, however, routine practice for prescribed ‘drugs’ as ward pharmacists will routinely check, advise or even change prescribed drugs according to accepted good practice. Yet again, as in the production of a national formulary and a raft of initiatives to improve prescribing, the pharmacy sector appears to have succeeded in striking first. This is quite possibly because medicine prescribing or dispensing errors are perhaps more clearly identifiable than sub-optimal or incorrect use of intravenous fluids. Both the laboratories and those clinicians with the greatest involvement in fluid management have some catching up to do.
For the purposes of this article, I distributed a brief email survey to a cohort of 165 clinical biochemists and chemical pathologists (local and via the ACB Clinical Practice Section mailbase) to ask whether their hospital had a dedicated intravenous fluid monitoring person/team who reviewed patients' intravenous fluid regimens. From a 66% response rate covering approximately 89 UK institutions, one (Sandwell) reported a dedicated intravenous fluids team, and one (Royal Liverpool) was in the process of setting up such a team.
As represented in qualifications offered to several answers, many biochemists do of course become involved with specific cases, such as patients receiving parenteral nutrition or those with severe hyponatraemia. Some intervention is also offered by ward pharmacists, although again this appears to be mostly an ad hoc, reactive response for example to hyponatraemia, rather than a planned proactive process to initiate and monitor the solutions and additions used.
Introducing a service to support and oversee the use of intravenous fluids would require engagement from all of the clinical specialities involved, alongside laboratory specialists and pharmacists, and would have significant albeit not enormous resource implications. It offers however considerable potential benefits both in terms of patient safety and outcome, but also potential compensatory savings from prolonged hospital admissions. Gaining universal buy-in would not be straightforward as there are undoubtedly alternative options to the guidelines that would produce the same physiological result and some clinicians will prefer to use regimens with which they have long experience and which may be entirely appropriate. Many hospitals may not have used some of the recommended solutions routinely, and any shift could have significant financial implications. As ever, therefore, the guidance should be used as such and not be interpreted as a mandatory policy. They should however prompt a careful re-examination of current practices.
Is it now time for intravenous fluid management to become identified as a discrete area of medicine with professionals (doctors, nurses or pharmacists) trained to review fluid prescribing in light of a patient's clinical and electrolyte status and act both as gatekeepers and educators on the ward? It could represent a major step forward in patient safety.
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