title: When to stop septic shock resuscitation: clues from a dynamic perfusion monitoring.
abstract: BACKGROUND
  The 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.
  
  
  METHODS
  We 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.
  
  
  RESULTS
  Some 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.
  
  
  CONCLUSIONS
  Perfusion-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.
authors.affiliation: Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 367, Santiago 8320000, Chile.
authors.forename: Glenn
authors.initials: G
authors.lastname: Hernandez
authors.affiliation: Unidad de Pacientes Críticos, Hospital Clínico, Universidad de Chile, Santos Dumont 999, Santiago 8380456, Chile.
authors.forename: Cecilia
authors.initials: C
authors.lastname: Luengo
authors.affiliation: Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 367, Santiago 8320000, Chile.
authors.forename: Alejandro
authors.initials: A
authors.lastname: Bruhn
authors.affiliation: Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 367, Santiago 8320000, Chile.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Kattan
authors.affiliation: Department of Critical Care Medicine, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos, 2350, Porto Alegre-RS, 90035-903, Brazil.
authors.forename: Gilberto
authors.initials: G
authors.lastname: Friedman
authors.affiliation: Intensive Care Unit, Fundación Valle del Lili, Av. Simón Bolívar Cra 98 # 18-49, Cali, Valle del Cauca, Colombia.
authors.forename: Gustavo A
authors.initials: GA
authors.lastname: Ospina-Tascon
authors.affiliation: Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 367, Santiago 8320000, Chile.
authors.forename: Andrea
authors.initials: A
authors.lastname: Fuentealba
authors.affiliation: Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 367, Santiago 8320000, Chile.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Castro
authors.affiliation: Departamento de Medicina Intensiva, Facultad de Medicina, Pontificia Universidad Católica de Chile, Marcoleta 367, Santiago 8320000, Chile.
authors.forename: Tomas
authors.initials: T
authors.lastname: Regueira
authors.affiliation: Unidad de Pacientes Críticos, Hospital Clínico, Universidad de Chile, Santos Dumont 999, Santiago 8380456, Chile.
authors.forename: Carlos
authors.initials: C
authors.lastname: Romero
authors.affiliation: Department of Intensive Care Adults, Erasmus MC University Medical Centre, Doctor Molewaterplein 50-60, Rotterdam, the Netherlands.
authors.forename: Can
authors.initials: C
authors.lastname: Ince
authors.affiliation: Department of Intensive Care Adults, Erasmus MC University Medical Centre, Doctor Molewaterplein 50-60, Rotterdam, the Netherlands.
authors.forename: Jan
authors.initials: J
authors.lastname: Bakker
keywords: Lactate; Microcirculation; Perfusion; Resuscitation; Septic shock