This month we turn our attention to the colloid debate. As most of you are aware, there has been a huge paradigm shift in the use of synthetic colloids in human medicine that has "bled" over (no pun intended) to the veterinary emergency and critical care arena.
For your reading pleasure, we have selected the following for your review. We really appreciate your comments and hope you will visit our blog!!
From the Jan/Feb issue of JVECC there are two salient (and open access) articles (this particular issue is free!)
State of the Art Reviews
The crystalloid‐colloid debate: Consequences of resuscitation fluid selection in veterinary critical care. Dava Cazzolli, Jennifer Prittie
Excellent review of the human and veterinary literature including prospective and restrospective studies, as well as experimental models. In human patients, colloids have failed to demonstrate outcome advantage. Clinical data indicates that hydroxyethyl starch solutions may be assoicated with significant adverse events. The ability to apply these findings to our species of interest is unknown however critical re-evaluation of veterinary resuscitation strategies is justified.
State of the Art Reviews
Controversies in the use of hydroxyethyl starch solutions in small animal emergency and critical care. Katja N. Adamik, Ivayla D. Yozova, Nadine Regenscheit
Both human and veterinary data synthesis is presented. No current veterinary consensusu recommendations on the use of hydroxyethyl starch exists. Veterinary studies are needed to achieve evidence to enable the formulation of the guidelines.
JVIM 2015; 29:276-285 Open Access
"Effects of Synthetic Colloid Administration on Coagulation in Healthy Dogs and Dogs with Systemic Inflammation."
V Gauthier, M.K. Holowaychuk, C.L. Kerr, A.M.E. Bersanas, R. Darren Wood
Bolus administration to dogs with systemic inflammation resulted in a transient hypocoagulation characterized by prolonged aPTT, decreased clot formation speed, decreased clot strength. and acquired Type 1 von Willebrand Disease.
Best Practices and Research. Clinical Anesthesiology 2014 Sept: 28 (3): 275-283 "Whats new in volume therapy in the Intensive Care Unit"
Synthetic Colloids are more effective than crystalloids in early shock resuscitation and surgery. However, these colloids may not be beneficial later in the course of intensive care treatment and are best avoided in patients with risk for Acute Kidney Injury 25208962
Annals of Intensive Care 2014; 4:38 "Resuscitation: Impact on Patient Outcomes"
There is no clear benefit associated with the use of colloids compared to crystalloids. Hydroxyethyl starch has been associated with increased incidence of acute kidney injury and the need for renal replacement therapy. 25612168
Here are some really cool Emergency and Critical Care Blogs and Podcasts
Dr. Mark Epstein discusses pain management in patients with interns at RIVER (Regional Institute for Veterinary Emergencies & Referrals) in Chattanooga, Tennessee.
More and more comments, articles and podcasts have been talking about the effects of using 0.9% saline as a resuscitative or maintenance fluid. Concerns seem to stem from it's acidifying effects (ie high chloride) or "for you quantitative acid base buffs" , the low strong ion difference. (low as in zero, that is). Another concern is the high levels of chloride in the distal tubular lumen of the nephron potentiating renal afferent artery constriction via tubuloglomerular feedback, decrease renal blood flow, possibly a contributing factor to AKI (acute kidney injury) in susceptable patients.....what do you think?
We've also been taught that 0.9% NaCl is the fluid of choice for hyperkalemia (in Addison's for example) but is it really? Since Addisonians are already hyponatremic, isn't the bigger concern a potential detrimental rapid rise in Na with significant volume resuscitation when using normal saline? Most of our balanced isotonic replacement crystalloids do have K+ but in minor amounts compared to the levels of the hyperkalemic patient. Just a thought.
What about 0.9% NaCl as the fluid of choice in hypercalcemia? Could one argue that it's is the increase in GFR from volume resuscitation with any isotonic replacement crystalloid that helps lower the calcium, not just normal saline? This concept will require a "deeper dive" than we have time for now (more to come)
You will also find that 0.9% NaCl is listed as the resuscitative fluid of choice for TBI (Traumatic Brain Injury). The logic behind this is that this fluid choice has the least free water and therefore is the least likely to contribute to cerebral edema (another topic for a deeper dive).
Over the next several months, we will look deeper into these recommendations, the evidence and expert opinion on the use of Normal Saline.
OH, and did you know you can learn so much from FOAVet?....asynchronous learning is the buzz word these days. Do you take advantage of all there is in the world of FOA goodness? And, best of all, you can learn when YOU are ready. Personally, I listen to a podcast every day on my way to work. How about you? If you have a fav podcast, please share it, Who knows, we may be podcast buddies, eh?