When to stop septic shock resuscitation: clues from a dynamic perfusion monitoring

Abstract

BackgroundThe decision of when to stop septic shock resuscitation is a critical but yet a relatively unexplored aspect of care. This is especially relevant since the risks of over-resuscitation with fluid overload or inotropes have been highlighted in recent years. A recent guideline has proposed normalization of central venous oxygen saturation and/or lactate as therapeutic end-points, assuming that these variables are equivalent or interchangeable. However, since the physiological determinants of both are totally different, it is legitimate to challenge the rationale of this proposal. We designed this study to gain more insights into the most appropriate resuscitation goal from a dynamic point of view. Our objective was to compare the normalization rates of these and other potential perfusion-related targets in a cohort of septic shock survivors.MethodsWe designed a prospective, observational clinical study. One hundred and four septic shock patients with hyperlactatemia were included and followed until hospital discharge. The 84 hospital-survivors were kept for final analysis. A multimodal perfusion assessment was performed at baseline, 2, 6, and 24 h of ICU treatment.ResultsSome variables such as central venous oxygen saturation, central venous-arterial pCO2 gradient, and capillary refill time were already normal in more than 70% of survivors at 6 h. Lactate presented a much slower normalization rate decreasing significantly at 6 h compared to that of baseline (4.0 [3.0 to 4.9] vs. 2.7 [2.2 to 3.9] mmol/L; p < 0.01) but with only 52% of patients achieving normality at 24 h. Sublingual microcirculatory variables exhibited the slowest recovery rate with persistent derangements still present in almost 80% of patients at 24 h.ConclusionsPerfusion-related variables exhibit very different normalization rates in septic shock survivors, most of them exhibiting a biphasic response with an initial rapid improvement, followed by a much slower trend thereafter. This fact should be taken into account to determine the most appropriate criteria to stop resuscitation opportunely and avoid the risk of over-resuscitation.

Is the macrocirculation really dissociated from the microcirculation in septic shock?

“…In other words, isolated severe sublingual microcirculatory dysfunction appears to be an uncommon event. Additionally, persistent mild to moderate sublingual microcirculatory alterations were still observed in septic shock survivors after early normalization of perfusion-related variables such as capillary refill time, central venous oxygen saturation *Correspondence: glennguru@gmail.com and venous-arterial PCO 2 gradients [10]. These findings could question the relevance of abnormal sublingual optical images in the absence of clinical hypoperfusion.…”

“…However, the treatment strategy is not modified, since the first major clinical responsibility is to rule out whether these abnormalities, either at the systemic or microcirculatory level, are still flow-sensitive. This is particularly relevant since risks of over-resuscitation have been repeatedly demonstrated over the last decade [10]. A multimodal analysis of macrohemodynamics, perfusion variables and eventually of microcirculatory status in the future might help in making the decision of when to stop further resuscitation in septic shock patients [10].…”

“…This is particularly relevant since risks of over-resuscitation have been repeatedly demonstrated over the last decade [10]. A multimodal analysis of macrohemodynamics, perfusion variables and eventually of microcirculatory status in the future might help in making the decision of when to stop further resuscitation in septic shock patients [10]. In this regard, a multimodal monitoring including systemic, peripheral, hepatosplanchnic and microcirculatory perfusion parameters was used in a study demonstrating that dobutamine increases systemic flow without affecting tissue perfusion in hyperdynamic septic shock [12].…”

Changes in peripheral perfusion relate to visceral organ perfusion in early septic shock: A pilot study

“…In septic shock patients, Ait-Oufella et al [10] showed that the capillary refill time measured at 6 hours of resuscitation was related to lactate levels, organ dysfunction, and mortality. Second, early normalization of parameters of skin perfusion including the capillary refill time was associated with survival from septic shock [11] and has been suggested as an indicator to stop fluid resuscitation in septic shock [12,13]. So far, however, it remains unclear why patients with abnormal peripheral perfusion have increased morbidity and mortality.…”

Principles of Fluid Management

“…23,24 There may be biphasic and/or variable responses to normalization of resuscitation variables (eg, rapid initial improvement in ScvO 2 , capillary refill time, and lactate clearance may be followed by slower trends thereafter) and further delays to normalization due to confounding by impaired hepatosplanchnic hypoperfusion. 25,26 Microcirculatory capillary blood flow (ie, use of sublingual orthogonal polarization spectral imaging) is commonly found abnormal among critically ill patients. Recent observational data have shown that disturbance in sublingual microcirculatory flow failed to correlate with patient survival, possibly because of a significant dissociation observed between sublingual and intestinal microcirculatory perfusion after fluid resuscitation.…”