Viva 4

A 54 yr old female is in ICU with sepsis after repair of a leaking ileo-colic anastamosis.  When you take over management on day 3, she is febrile and vasodilated.  T 38.5O C, pulse 110 / min, MAP 58 mm Hg. CVP 12 mm Hg. Urine output  15 mL/hr. Plasma  creatinine is normal, but rising.

Your colleague has been giving fluid replacement guided by arterial waveform analysis, administering a fluid load when Stroke Volume Variation > 13%.  She now has generalized oedema, with an acute weight gain of 12 kg.
Currently cardiac index = 4.1 L/min/m2, Stroke Volume Variation = 19%

Q1. What is Stroke Volume Variation designed to monitor?

The rest of the viva focussed on fluid responsiveness, complications of fluid therapy and   a discussion on the suitability of crystalloids and colloids in various clinical situations.

°     Candidates were confused about the concept of fluid responsiveness, and frequently equated fluid responsiveness to a low CVP. They could not explain why CVP was not a reliable measure of fluid status or responsiveness.
°     Many candidates were not familiar with the VISEP study (candidates were not required to know the name of the study but an awareness of a large RCT on starches and their potential problems was important).
°    Many were unaware of  the  composition and  associated drawbacks of  Compound Sodium Lactate solution

Disclaimer: the viva stem above may be an original CICM stem, acquired from their publicly available past papers. Or, perhaps it is a slightly altered version of the original CICM stem. Or, it is a completely original viva stem, concocted by the monstrously amoral author of Deranged Physiology for nothing more than his own personal amusement. In either case, because the college do not make the main viva text or marking criteria available, almost everything here has been confabulated. It might sound like a plausible viva and it could be used for the purpose of practice, but all should be aware that it does not represent the "true" canonical CICM viva station.