Keynote Message
Fluid status and fluid responsiveness remain hot topics of debate in emergency and critical care. The concept of initial stabilisation using high volume boluses of crystalloids and/or colloids to improve tissue perfusion and oxygenation has become commonplace. However, not all shock patients will benefit from these large volumes (think of patients already having a normal volume status, or patients suffering from cardiac disease or dysfunction).
Moreover, even for patients in which a or some boluses improve cardiac output, tissue perfusion and hence oxygenation, the de-escalation and avoidance of overzealous crystalloid administration avoids destruction of the glycocalyx and helps to preserve the microcirculation. Therefore, proper evaluation of fluid responsiveness is essential to help improve patient outcome even further.
As proper use of fluids saves lives, some proper knowledge on how to monitor fluid status and fluid responsiveness is key to any practitioner confronted with ECC patients, and undoubtedly also to internists.
In this session, an overview of past, current, and future methods to assess volume status and volume responsiveness in human and veterinary medicine will be given. This session will then focus on the use of ultrasonography to guide fluid therapy and initial stabilisation in small animal medicine, and this technique will be illustrated with some clinical case scenarios.
Key References
1. Theerawit P, Morasert T, Sutherasan Y. Inferior vena cava diameter variation compared with pulse pressure variation as predictors of fluid responsiveness in patients with sepsis. Journal of Critical Care. 2016;36:246–251. De Lorenzo RA, Morris MJ, Williams JB, et al. Does a simple bedside sonographic measurement of the inferior vena cava correlate to central venous pressure? The Journal of Emergency Medicine. 2012;42:429–436.
2. Zhang Z, Xu X, Ye S, et al. Ultrasonographic measurement of the respiratory variation in the inferior vena cava diameter is predictive of fluid responsiveness in critically ill patients: systematic review and meta-analysis. Ultrasound in Medicine & Biology. 2014;40:845–853.
3. Laher AE, Watermeyer MJ, Buchanan SK, et al. A review of hemodynamic monitoring techniques, methods and devices for the emergency physician. The American Journal of Emergency Medicine. (In press)
4. Darnis E, Merveille AC, Desquilbet L, et al. Inter-observer agreement when measuring ultrasonographic caudal vena cava diameter and basic echocardiographic parameters by non-cardiologist veterinarians following a 6-hour training course. Submitted to Journal of Veterinary Emergency and Critical Care.
5. Darnis E, Merveille AC, Desquilbet L, et al. Establishment of the caudal vena cava reference values in healthy dogs through different views by CV-FAST ultrasonography. Submitted to Journal of Veterinary Emergency and Critical Care.
6. Merveille AC, Darnis E, Boysen S, et al. Caudal vena cava assessment in dogs with right-sided congestive heart failure: a pilot study. Abstract submitted to the ECVIM congress.