74
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: found
      Is Open Access

      Severe hyperlactatemia with normal base excess: a quantitative analysis using conventional and Stewart approaches

      research-article

      Read this article at

      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Introduction

          Critically ill patients might present complex acid–base disorders, even when the pH, PCO 2, [HCO 3 -], and base excess ([BE]) levels are normal. Our hypothesis was that the acidifying effect of severe hyperlactatemia is frequently masked by alkalinizing processes that normalize the [BE]. The goal of the present study was therefore to quantify these disorders using both Stewart and conventional approaches.

          Methods

          A total of 1,592 consecutive patients were prospectively evaluated on intensive care unit admission. Patients with severe hyperlactatemia (lactate level ≥ 4.0 mmol/l) were grouped according to low or normal [BE] values (<-3 mmol/l or >-3 mmol/l).

          Results

          Severe hyperlactatemia was present in 168 of the patients (11%). One hundred and thirty-four (80%) patients had low [BE] levels while 34 (20%) patients did not. Shock was more frequently present in the low [BE] group (46% versus 24%, P = 0.02) and chronic obstructive pulmonary disease in the normal [BE] group (38% versus 4%, P < 0.0001). Levels of lactate were slightly higher in patients with low [BE] (6.4 ± 2.4 mmol/l versus 5.6 ± 2.1 mmol/l, P = 0.08). According to our study design, the pH, [HCO 3 -], and strong-ion difference values were lower in patients with low [BE]. Patients with normal [BE] had lower plasma [Cl -] (100 ± 6 mmol/l versus 107 ± 5 mmol/l, P < 0.0001) and higher differences between the changes in anion gap and [HCO 3 -] (5 ± 6 mmol/l versus 1 ± 4 mmol/l, P < 0.0001).

          Conclusion

          Critically ill patients may present severe hyperlactatemia with normal values of pH, [HCO 3 -], and [BE] as a result of associated hypochloremic alkalosis.

          Related collections

          Most cited references39

          • Record: found
          • Abstract: found
          • Article: found
          Is Open Access

          Lactate versus non-lactate metabolic acidosis: a retrospective outcome evaluation of critically ill patients

          Introduction Acid–base abnormalities are common in the intensive care unit (ICU). Differences in outcome exist between respiratory and metabolic acidosis in similar pH ranges. Some forms of metabolic acidosis (for example, lactate) seem to have worse outcomes than others (for example, chloride). The relative incidence of each type of disorder is unknown. We therefore designed this study to determine the nature and clinical significance of metabolic acidosis in critically ill patients. Methods An observational, cohort study of critically ill patients was performed in a tertiary care hospital. Critically ill patients were selected on the clinical suspicion of the presence of lactic acidosis. The inpatient mortality of the entire group was 14%, with a length of stay in hospital of 12 days and a length of stay in the ICU of 5.8 days. Results We reviewed records of 9,799 patients admitted to the ICUs at our institution between 1 January 2001 and 30 June 2002. We selected a cohort in which clinicians caring for patients ordered a measurement of arterial lactate level. We excluded patients in which any necessary variable required to characterize an acid–base disorder was absent. A total of 851 patients (9% of ICU admissions) met our criteria. Of these, 548 patients (64%) had a metabolic acidosis (standard base excess < -2 mEq/l) and these patients had a 45% mortality, compared with 25% for those with no metabolic acidosis (p < 0.001). We then subclassified metabolic acidosis cases on the basis of the predominant anion present (lactate, chloride, or all other anions). The mortality rate was highest for lactic acidosis (56%); for strong ion gap (SIG) acidosis it was 39% and for hyperchloremic acidosis 29% (p < 0.001). A stepwise logistic regression model identified serum lactate, SIG, phosphate, and age as independent predictors of mortality. Conclusion In critically ill patients in which a measurement of lactate level was ordered, lactate and SIG were strong independent predictors of mortality when they were the major source of metabolic acidosis. Overall, patients with metabolic acidosis were nearly twice as likely to die as patients without metabolic acidosis.
            Bookmark
            • Record: found
            • Abstract: found
            • Article: not found

            Increased vascular permeability: a major cause of hypoalbuminaemia in disease and injury.

            The rate of loss of albumin to the tissue spaces (measured as transcapillary escape rate) rose by more than 300% in patients with septic shock, and the average increase within 7 h of cardiac surgery was 100%. The transcapillary escape rate in cachectic cancer patients was twice that of a group of healthy individuals. The rate of loss of albumin to the tissue spaces is normally 5%/h, which is more than 10 times the rates of synthesis and catabolism, and these large rate increases indicate that increased vascular permeability is an important cause of the lowered concentration of albumin commonly seen in acute and chronic disease.
              Bookmark
              • Record: found
              • Abstract: found
              • Article: not found

              Comparison of norepinephrine and dobutamine to epinephrine for hemodynamics, lactate metabolism, and gastric tonometric variables in septic shock: a prospective, randomized study.

              To compare the effects of norepinephrine and dobutamine to epinephrine on hemodynamics, lactate metabolism, and gastric tonometric variables in hyperdynamic dopamine-resistant septic shock. A prospective, intervention, randomized clinical trial. Adult medical/surgical intensive care unit in a university hospital. 30 patients with a cardiac index (CI) > 3.51 x min(-1) x m(-2) and a mean arterial pressure (MAP) < or = 60 mmHg after volume loading and dopamine 20 microg/kg per min and either oliguria or hyperlactatemia. Patients were randomized to receive an infusion of either norepinephrine-dobutamine or epinephrine titrated to obtain an MAP greater than 80 mmHg with a stable or increased CI. Baseline measurements included: hemodynamic and tonometric parameters, arterial and mixed venous gases, and lactate and pyruvate blood levels. These measurements were repeated after 1, 6, 12, and 24 h. All the patients fulfilled the therapeutic goals. No statistical difference was found between epinephrine and norepinephrine-dobutamine for systemic hemodynamic measurements. Considering metabolic and tonometric measurements and compared to baseline values, after 6 h, epinephrine infusion was associated with an increase in lactate levels (from 3.1 +/- 1.5 to 5.9 +/- 1.0 mmol/l;p < 0.01), while lactate levels decreased in the norepinephrine-dobutamine group (from 3.1 +/- 1.5 to 2.7 +/- 1.0 mmol/l). The lactate/pyruvate ratio increased in the epinephrine group (from 15.5 +/- 5.4 to 21 +/- 5.8; p < 0.01) and did not change in the norepinephrine-dobutamine group (13.8 +/- 5 to 14 +/- 5.0). Gastric mucosal pH (pHi) decreased (from 7.29 +/- 0.11 to 7.16 +/- 0.07; p < 0.01) and the partial pressure of carbon dioxide (PCO2) gap (tonometer PCO2-arterial PCO2) increased (from 10 +/- 2.7 to 14 +/- 2.7 mmHg; p < 0.01) in the epinephrine group. In the norepinephrine-dobutamine group pHi (from 7.30 +/- 0.11 to 7.35 +/- 0.07) and the PCO2 gap (from 10 +/- 3.0 to 4 +/- 2.0 mmHg) were normalized within 6 h (p < 0.01). The decrease in pHi and the increase in the lactate/pyruvate ratio in the epinephrine group was transient, since it returned to normal within 24 h. Considering the global hemodynamic effects, epinephrine is as effective as norepinephrine-dobutamine. Nevertheless, gastric mucosal acidosis and global metabolic changes observed in epinephrine-treated patients are consistent with a markedly inadequate, although transient, splanchnic oxygen utilization. The metabolic and splanchnic effects of the combination of norepinephrine and dobutamine in hyperdynamic dopamine-resistant septic shock appeared to be more predictable and more appropriate to the current goals of septic shock therapy than those of epinephrine alone.
                Bookmark

                Author and article information

                Journal
                Crit Care
                Critical Care
                BioMed Central
                1364-8535
                1466-609X
                2008
                8 May 2008
                : 12
                : 3
                : R66
                Affiliations
                [1 ]Servicio de Terapia Intensiva, Sanatorio Otamendi y Miroli, Buenos Aires, Argentina
                Article
                cc6896
                10.1186/cc6896
                2481449
                18466618
                e4f18550-1ff1-4717-9c0a-dd45f0608a24
                Copyright © 2008 Tuhay et al.; licensee BioMed Central Ltd.

                This is an open access article distributed under the terms of the Creative Commons Attribution License ( http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

                History
                : 10 March 2008
                : 8 April 2008
                : 28 April 2008
                : 8 May 2008
                Categories
                Research

                Emergency medicine & Trauma
                Emergency medicine & Trauma

                Comments

                Comment on this article