I was recently questioned by one of our residents as to whether there is sound evidence that crystalloids were better than colloid solutions in trauma resuscitation. I said, “yes, of course.” But he was persistent and asked further, “Are you sure?” It forced me to scratch my head. I had the option of relying on my own haphazard recollections, or to go to the literature. So I said, “Let’s look it up.” Normally at this point I would have spent hours plugging away at PubMed to come up with the evidence. Instead, using a different method, I came up with a reasonably comprehensive overview of the highest quality evidence on the subject within a matter of minutes.
Some criticize the notion of searching in real time for evidence-based answers to clinical questions that arise in the emergency department. It is assumed that aggregating all of the relevant primary studies and critically appraising each article found is far too laborious to be effective in a clinically contemporaneous fashion. Taking care of patient flow is difficult enough without consulting Medline every five minutes, right? The truth is that quickly finding the best evidence is not as difficult as it sounds; it’s all a matter of where you choose to start.
The TRIP Database
The TRiP (Turning Research into Practice) Database (www.tripdatabase.com) is a comprehensive meta-search engine which is designed to be just such a starting place. TRiP began in 1997 with the goal of optimizing the use of evidence-based medical principles to answer clinical questions within a relevant time frame. Well over 75 individual sources of medical information are indexed and searched simultaneously, providing the user with direct hyperlinked access to the largest collection of evidence based material available online. This includes EBM articles from premier journals such as BMJ, JAMA, Lancet, NEJM, as well as the higher-order synopses, syntheses, and summaries.
By simply entering the keywords “crystalloid” and “colloid,” our search was underway…
Starting the Search
The results were provided in order of relevance, scored by TRIP’s internal scoring system which takes into account the quality of the evidence, timeliness, keyword density, and so on. Results can be further filtered by the type of source (Evidence Based Synopses, Clinical Questions, Guidelines, E-Textbooks, Systematic Reviews etc.), or by specialty of interest, and appear in rank order by the quality and timeliness of the evidence. All results were linked directly to their online source or to their PubMed citation.
Our initial results included articles discussing IV solutions from a variety of clinical perspectives, but we were only interested in the use of colloid and crystalloid solutions in an emergency or critical care environment. Fortunately, TRIP let us do that with a simple pull down menu.
Filtering Search Results by Specialty
Right near the top of the list of results appear three big hits. One, a link to a systematic review2, another to a critical appraisal of a 2001 meta-analysis,3 and third a report summarizing three systematic reviews4. Each could be accessed with a click, or – in select cases – the conclusion of each article was available right from TRIP’s list of results.
Jump to the Conclusion
In the case of our search, all of the results point to the same conclusion: there is no evidence that colloid solutions were more effective than crystalloids in reducing mortality in patients requiring volume replacement who are injured or critically ill. I noted considerable discussion of the 2004 NEJM publication of the SAFE Trial5, a landmark study of almost 7000 subjects, drawing similar conclusions. Just to prove my point, it was on my screen with only a few additional clicks through TRIP’s links to PubMed/MedLine.
Not only was TRIP deceptively simple to use, it was free. Rather than spending time bouncing between multiple online resources, the TRIP Database was able to guide us through a hierarchical approach to existing preprocessed information sources. By surveying huge amounts of data we were able to get our hands on the best available evidence in a startlingly short amount of time.
The Hierarchy of Preprocessed Evidence
High quality research is of little use to most physicians unless specific questions can be posed and answered in a timely manner. Familiarity with high-efficiency techniques and tools such as the TRIP Database will not only improve the scientific basis of your clinical decisions, but may actually save you enough time to squeeze in the occasional trip to the bathroom.
Rupinder S. Sahsi BSc MD CCFP(EM) is an Assistant Clinical Professor at McMaster University, and a Faculty Member of the Best Evidence in Emergency Medicine (BEEM) Investigator Group (www.beemcourse.com).
1 Haynes, RB. “Of studies, syntheses, synopses, summaries, and systems: the “5S” evolution of information services for evidence-based healthcare decisions.” Evidence Based Medicine 2006 Dec;11(6):162-4
2 Perel P, Roberts I. “Colloids versus Crystalloids for fluid resuscitation in critically ill patients.” Cochrane Database of Systematic Reviews 2007(Updated July 1, 2007), Issue 4, Art No: CD000567.
3 Schierhout, Roberts I. “Fluid resuscitation with colloid or crystalloid in critically ill patients: a systematic review of randomized trials.” BMJ 1998; 316:961-964.
4 Centre for Clinical Effectiveness (2001) Colloid or crystalloid solutions for fluid resuscitation [Online] Available from http://www.med.monash.edu.au/publichealth/cce [Accessed March 1, 2008]
5 Finfer S, Bellomo S, Boyce N, French J, Myburgh J, Norton R. “A comparison of albumin and saline for fluid resuscitation in the intensive care unit.” New England Journal of Medicine, 2007 May 27;250(22):2247-56.