Dynamic parameters of fluid responsiveness, including PPV and SW, have been shown to be superior to traditional static parameters in predicting rise in stroke volume following a fluid challenge (6, 7).
This endogenous fluid challenge as a surrogate method for intravascular fluid infusion sufficiently increases the mean systemic pressure to result in an increase of venous return and subsequent SV increase (8).
Of the 42 patients, 19 (45%) responded to
fluid challenge, whereas 23 (55%) did not.{Table 1}
The actual acPED [less than or equal to] 0 (p.d.u.) was found in 296 (61.7 %) of the mini
fluid challenges defined as non-responders.
where [PD.sub.i] is the plasma dilution after the
fluid challenge number i, Hb is the initial hemoglobin concentration obtained before the first
fluid challenge, [Hb.sub.i] is the hemoglobin concentration obtained after the
fluid challenge number i, and Hct is the initial hematocrit value obtained before the first
fluid challenge (since noninvasive Hct is not available during the noninvasive determination of the PD, the initial Hct is derived by dividing the noninvasive initial Hb by 330, which is the mean value of the normal range for the mean cell hemoglobin concentration).
Percent change in stroke volume following
fluid challenge correlated with FTc (r=-0.81, P=0.004) (Figure 2).
Marmaite, "Goal directed fluid therapy revised: indirect monitoring of interstitial fluid accumulation during mini
fluid challenges with crystalloids", Open Conf Proc J.,vol.
Fluid challenge in non-responsive patients may also delay institution of effective treatment, such as inotropes and vasopressors.
Studies have demonstrated that the reliability of blood pressure as a surrogate of stroke volume was poor,[sup][19] but blood pressure remains the most widely used parameter to assess the response of
fluid challenge.[sup][3] Lakhal et al.
Calculation of normalised acGAP is performed in each individual from a pool after the first mini
fluid challengeThe infusion duration of
fluid challenge test was 3 min.
Treatment for septic shock was standardized,[sup][4] including vasopressors (norepinephrine with epinephrine as a rescue therapy) to MAP, in addition to repeated
fluid challenges with crystalloids, natural albumin, and artificial colloids (hydroxyethyl starch solutions) to achieve a CVP of 8–12 mmHg, to maintain a MAP of at least 65 mmHg and to ensure that the urine output was at least 0.5 ml*kg [sup]−1*h [sup]−1.