Clinical use of lactate testing in shock states

Should lactate be added to Tokyo criteria for the evaluation of patients with acute cholangitis?

BACKGROUND

Tokyo guidelines (TG13/18) are used for the severity assessment of acute cholangitis (AC). Lactate is a clinical marker of tissue hypoxia and disease severity, independent from blood pressure.

AIM

The aim of this study is to investigate the relationship between blood lactate level and TG13/18 criteria in patients diagnosed with AC.

METHODS

One hundred fifteen patients with AC were included in this retrospective study. Demographic characteristics of the patients and laboratory data were scanned from their hospital medical records. According to TG13/18 guidelines, the patients were divided into 3 groups as mild (grade 1), moderate (grade 2), and severe (grade 3) AC.

RESULTS

Sixty three (54.7%) of the patients were grade 1, 37 (32.1%) were grade 2, and 15 (13.0%) were grade 3. It was found that blood lactate level increased significantly from grade 1 to grade 3 (p < 0.001). In logistic regression analysis, white blood cell (WBC) count, total bilirubin and blood lactate levels independently determined the patients to be grade 2 or 3 AC. When the blood lactate cut-off value was taken as 16.5 mg/dL, we diagnosed grade 2 or 3 AC with a sensitivity of 78.8% and a specificity of 75.7%. From among lactate, WBC, and C reactive protein, lactate showed the highest value regarding the area under the curve, which is an index for predicting grade III upon ROC analysis.

CONCLUSION

The blood lactate level is associated with the severity of AC. In addition to TG13/18 guidelines, blood lactate level can be a useful biomarker in the severity grading of AC.

Blood lactate and lactate kinetics as treatment and prognosis markers for tissue hypoperfusion

Objective: Blood lactate concentration (L) and lactate kinetic (LK) over time might be a helpful marker of the shock severity. The purpose of this study is to analyze whether the L and LK could correlate with the outcome and the therapy of patients with different types of shock.Methods: Design: A 3.5-year retrospective observational study. Patients: Eighteen years of age or older, diagnosed with shock were included. Arterial L measurements were performed upon admission and approximatively 3 and 6 h later. The evolution of lactate over this period of time was correlated with the outcome and therapy. Interventions: Univariate and multivariable statistical tests were performed to examine the relation between the initial L/LK and the in-hospital mortality, total mortality, length of stay (LOS), the LOS at the intensive care unit and the administered therapy. The optimal cut-off point of the LK over time to predict the mortality was calculated.Results: The initial L and the 6 h LK were significantly associated with the outcome. The higher the initial L and lower the LK, the higher the risk of mortality in the hospital or within 6 months. Moreover, the higher the initial L and lower the 6 h LK, the longer was the LOS. A relation between the initial L/LK and the required therapy was found. The optimal cut-off for the 6-h LK is 38.1%. Patients with a 6 h LK >38.1% had a significantly higher chance of survival.Conclusions: A significant relationship between the L/6-h LK and the outcome and treatment was found. The optimal survival cut-off point of 6 h LK in our study was 38.1%.

Shock - Classification and Pathophysiological Principles of Therapeutics

The management of patients with shock is extremely challenging because of the myriad of possible clinical presentations in cardiogenic shock, septic shock and hypovolemic shock and the limitations of contemporary therapeutic options. The treatment of shock includes the administration of endogenous catecholamines (epinephrine, norepinephrine, and dopamine) as well as various vasopressor agents that have shown efficacy in the treatment of the various types of shock. In addition to the endogenous catecholamines, dobutamine, isoproterenol, phenylephrine, and milrinone have served as the mainstays of shock therapy for several decades. Recently, experimental studies have suggested that newer agents such as vasopressin, selepressin, calcium-sensitizing agents like levosimendan, cardiac-specific myosin activators like omecamtiv mecarbil (OM), istaroxime, and natriuretic peptides like nesiritide can enhance shock therapy, especially when shock presents a more complex clinical picture than normal. However, their ability to improve clinical outcomes remains to be proven. It is the purpose of this review to describe the mechanism of action, dosage requirements, advantages and disadvantages, and specific indications and contraindications for the use of each of these catecholamines and vasopressors, as well as to elucidate the most important clinical trials that serve as the basis of contemporary shock therapy.

Prognostic utility of plasma lactate measured between 24 and 48 h after initiation of early goal-directed therapy in the management of sepsis, severe sepsis, and septic shock

Background

Based on the proven efficacy of lactate in predicting mortality and morbidity in sepsis when measured early in the resuscitative protocol, our group hypothesized that this utility extends later in the course of care. This study sought to investigate the prognostic potential of plasma lactate clearance measured 24–48 h after the initiation of treatment for nonsurgical patients with sepsis, severe sepsis, and septic shock.

Methods

Plasma lactate values, measured 24–48 h after the initiation of treatment, were collected in nonsurgical septic, severe septic, and septic shock patients. The primary outcome was 30-day mortality, while secondary outcomes included requirements for vasopressors and boluses of intravenous fluids. Analysis of these three outcomes was performed while controlling for clinical severity as measured by Sequential Organ Failure Assessment (SOFA), renal dysfunction, and hepatic dysfunction. Lactate clearance was defined as the percent change in plasma lactate levels measured after 24–48 h of treatment from the plasma lactate level at initial presentation.

Results

Two hundred twenty-nine nonsurgical patients were divided into two groups, clearers (above median lactate clearance [31.6 %]) and nonclearers (below median lactate clearance [31.6 %]). The adjusted odds ratio of mortality in clearers compared to nonclearers was 0.39 (CI 0.20–0.76) (p = 0.006). For vasopressor requirement, the adjusted odds ratio was 0.41 (CI 0.21–0.79) in clearers compared to nonclearers (p = 0.008). For intravenous fluid bolus requirement, the adjusted odds ratio was 0.81 (CI 0.48–1.39) in clearers compared to nonclearers (p = 0.45).

Conclusions

Lower plasma lactate clearance 24–48 h after the initiation of treatment is associated with higher 30-day mortality and requirements for vasopressors in nonsurgical septic patients and may be a useful noninvasive measurement for guiding late-sepsis treatment. Further investigation looking at mechanisms and therapeutic targets to improve lactate clearance in late sepsis may improve patient mortality and outcomes.

Lactate kinetics in sepsis and septic shock: a review of the literature and rationale for further research

Over the last two decades, there have been vast improvements in sepsis-related outcomes, largely resulting from the widespread adoption of aggressive fluid resuscitation and infection control. With increased understanding of the pathophysiology of sepsis, novel diagnostics and resuscitative interventions are being discovered. In recent years, few diagnostic tests like lactate have engendered more attention and research in the sepsis arena. Studies highlighting lactate’s prognostic potential for mortality and other outcomes are ubiquitous and largely focus on the early stage of sepsis management, defined as the initial 6 h and widely referred to as the “golden hours.” Additional investigations, although more representative of surgical and trauma patients, suggest that lactate measurements beyond 24 h from the initiation of resuscitation continue to have predictive and prognostic utility. This review summarizes the current research and evidence regarding lactate’s utility as a prognosticator of clinical outcomes in both early and late sepsis management, defines the mechanism of lactate production and clearance, and identifies areas warranting further research.

The role of serum lactate in the acute care setting

Acute care services are increasingly faced with the double burden of high patient acuity and limited resources. Early identification of patients who are sick or who have the potential to deteriorate rapidly is crucial so that these resources may be allocated to those in greatest need. Traditional measures of illness and end points of resuscitation, such as vital signs, often fail to identify occult hypoperfusion with certain disease processes associated with high morbidity and mortality. Thus, biochemical markers that may predict illness earlier are becoming more relevant. We present a review of the evidence behind use of the serum lactate level in this setting.