Cumulative lactate and hospital mortality in ICU patients

BACKGROUND: Both hyperlactatemia and persistence of hyperlactatemia have been associated with bad outcome. We compared lactate and lactate-derived variables in outcome prediction. METHODS: Retrospective observational study. Case records from 2,251 consecutive intensive care unit (ICU) patients admitted between 2001 and 2007 were analyzed. Baseline characteristics, all lactate measurements, and in-hospital mortality were recorded. The time integral of arterial blood lactate levels above the upper normal threshold of 2.2 mmol/L (lactate-time-integral), maximum lactate (max-lactate), and time-to-first-normalization were calculated. Survivors and nonsurvivors were compared and receiver operating characteristic (ROC) analysis were applied. RESULTS: A total of 20,755 lactate measurements were analyzed. Data are srpehown as median [interquartile range]. In nonsurvivors (n = 405) lactate-time-integral (192 [0–1881] min·mmol/L) and time-to-first normalization (44.0 [0–427] min) were higher than in hospital survivors (n = 1846; 0 [0–134] min·mmol/L and 0 [0–75] min, respectively; all p < 0.001). Normalization of lactate <6 hours after ICU admission revealed better survival compared with normalization of lactate >6 hours (mortality 16.6% vs. 24.4%; p < 0.001). AUC of ROC curves to predict in-hospital mortality was the largest for max-lactate, whereas it was not different among all other lactate derived variables (all p > 0.05). The area under the ROC curves for admission lactate and lactate-time-integral was not different (p = 0.36). CONCLUSIONS: Hyperlactatemia is associated with in-hospital mortality in a heterogeneous ICU population. In our patients, lactate peak values predicted in-hospital mortality equally well as lactate-time-integral of arterial blood lactate levels above the upper normal threshold

Treatment of hypophosphatemia in the intensive care unit: a review

Introduction: Currently no evidence-based guideline exists for the approach to hypophosphatemia in critically ill patients. Methods: We performed a narrative review of the medical literature to identify the incidence, symptoms, and treatment of hypophosphatemia in critically ill patients. Specifically, we searched for answers to the questions whether correction of hypophosphatemia is associated with improved outcome, and whether a certain treatment strategy is superior. Results: Incidence: hypophosphatemia is frequently encountered in the intensive care unit; and critically ill patients are at increased risk for developing hypophosphatemia due to the presence of multiple causal factors. Symptoms: hypophosphatemia may lead to a multitude of symptoms, including cardiac and respiratory failure. Treatment: hypophosphatemia is generally corrected when it is symptomatic or severe. However, although multiple studies confirm the efficacy and safety of intravenous phosphate administration, it remains uncertain when and how to correct hypophosphatemia. Outcome: in some studies, hypophosphatemia was associated with higher mortality; a paucity of randomized controlled evidence exists for whether correction of hypophosphatemia improves the outcome in critically ill patients. Conclusions: Additional studies addressing the current approach to hypophosphatemia in critically ill patients are required. Studies should focus on the association between hypophosphatemia and morbidity and/or mortality, as well as the effect of correction of this electrolyte disorde

The incidence of low venous oxygen saturation on admission to the intensive care unit: a multi-center observational study in The Netherlands

Background Low mixed or central venous saturation (S(c)vO(2)) can reveal global tissue hypoxia and therefore can predict poor prognosis in critically ill patients. Early goal directed therapy (EGDT), aiming at an ScvO(2) >= 70%, has been shown to be a valuable strategy in patients with sepsis or septic shock and is incorporated in the Surviving Sepsis Campaign guidelines. Methods In this prospective observational multi-center study, we determined central venous pressure (CVP), hematocrit, pH, lactate and ScvO(2) or SvO(2) in a heterogeneous group of critically ill patients early after admission to the intensive care units (ICUs) in three Dutch hospitals. Results Data of 340 acutely admitted critically ill patients were collected. The mean SvO(2) value was > 65% and the mean ScvO(2) value was > 70%. With mean CVP of 10.3 +/- 5.5 mmHg, lactate plasma levels of 3.6 +/- 3.6 and acute physiology, age and chronic health evaluation (APACHE II) scores of 21.5 +/- 8.3, the in-hospital mortality of the total heterogeneous population was 32.0%. A subgroup of septic patients (n = 125) showed a CVP of 9.8 +/- 5.4 mmHg, mean ScvO(2) values of 74.0 +/- 10.2%, where only 1% in this subgroup revealed a ScvO(2) value <50%, and lactate plasma levels of 2.7 +/- 2.2 mmol/l with APACHE II scores 20.9 +/- 7.3. Hospital mortality of this subgroup was 26%. Conclusion The incidence of low ScvO(2) values for acutely admitted critically ill patients is low in Dutch ICUs. This is especially true for patients with sepsis/septic shock

Purification and characterization of an alcohol dehydrogenase from 1,2-propanediol-grown Desulfovibriostrain HDv

The sulfate-reducing bacterium Desulfovibrio strain HDv (DSM 6830) grew faster on (S)- and on (R, S)-1,2-propanediol (µmax 0.053 h–1) than on (R)-propanediol (0.017 h–1) and ethanol (0.027 h–1). From (R, S)-1,2-propanediol-grown cells, an alcohol dehydrogenase was purified. The enzyme was oxygen-labile, NAD-dependent, and decameric; the subunit mol. mass was 48 kDa. The N-terminal amino acid sequence indicated similarity to alcohol dehydrogenases belonging to family III of NAD-dependent alcohol dehydrogenases, the first 21 N-terminal amino acids being identical to those of the Desulfovibrio gigas alcohol dehydrogenase. Best substrates were ethanol and propanol (Km of 0.48 and 0.33 mM, respectively). (R, S)-1,2-Propanediol was a relatively poor substrate for the enzyme, but activities in cell extracts were high enough to account for the growth rate. The enzyme showed a preference for (S)-1,2-propanediol over (R)-1,2-propanediol. Antibodies raised against the alcohol dehydrogenase of D. gigas showed cross-reactivity with the alcohol dehydrogenase of Desulfovibrio strain HDv and with cell extracts of six other ethanol-grown sulfate-reducing bacteria.

No agreement of mixed venous and central venous saturation in sepsis, independent of sepsis origin

Introduction: Controversy remains regarding the relationship between central venous saturation (ScvO(2)) and mixed venous saturation (SvO(2)) and their use and interchangeability in patients with sepsis or septic shock. We tested the hypothesis that ScvO(2) does not reliably predict SvO(2) in sepsis. Additionally we looked at the influence of the source (splanchnic or non-splanchnic) of sepsis on this relationship. Methods: In this prospective observational two-center study we concurrently determined ScvO(2) and SvO(2) in a group of 53 patients with severe sepsis during the first 24 hours after admission to the intensive care units in 2 Dutch hospitals. We assessed correlation and agreement of ScvO(2) and SvO(2), including the difference, i.e. the gradient, between ScvO(2) and SvO(2) (ScvO(2) -SvO(2)). Additionally, we compared the mean differences between ScvO(2) and SvO(2) of both splanchnic and non-splanchnic group. Results: A total of 265 paired blood samples were obtained. ScvO(2) overestimated SvO(2) by less than 5% with wide limits of agreement. For changes in ScvO(2) and SvO(2) results were similar. The distribution of the (ScvO(2) - SvO(2)) (< 0 or >= 0) was similar in survivors and nonsurvivors. The mean (ScvO(2) - SvO(2)) in the splanchnic group was similar to the mean (ScvO(2) - SvO(2)) in the non-splanchnic group (0.8 +/- 3.9% vs. 2.5 +/- 6.2%; P = 0.30). O2ER (P = 0.23) and its predictive value for outcome (P = 0.20) were similar in both groups. Conclusions: ScvO(2) does not reliably predict SvO(2) in patients with severe sepsis. The trend of ScvO(2) is not superior to the absolute value in this context. A positive difference (ScvO(2) -SvO(2)) is not associated with improved outcome

Mechanical ventilation with lower tidal volumes does not influence the prescription of opioids or sedatives

INTRODUCTION: We compared the effects of mechanical ventilation with a lower tidal volume (V(T)) strategy versus those of greater V(T) in patients with or without acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) on the use of opioids and sedatives. METHODS: This is a secondary analysis of a previously conducted before/after intervention study, which consisting of feedback and education on lung protective mechanical ventilation using lower V(T). We evaluated the effects of this intervention on medication prescriptions from days 0 to 28 after admission to our multidisciplinary intensive care unit. RESULTS: Medication prescriptions in 23 patients before and 38 patients after intervention were studied. Of these patients, 10 (44%) and 15 (40%) suffered from ALI/ARDS. The V(T) of ALI/ARDS patients declined from 9.7 ml/kg predicted body weight (PBW) before to 7.8 ml/kg PBW after the intervention (P = 0.007). For patients who did not have ALI/ARDS there was a trend toward a decline from 10.2 ml/kg PBW to 8.6 ml/kg PBW (P = 0.073). Arterial carbon dioxide tension was significantly greater after the intervention in ALI/ARDS patients. Neither the proportion of patients receiving opioids or sedatives, or prescriptions at individual time points differed between pre-intervention and post-intervention. Also, there were no statistically significant differences in doses of sedatives and opioids. Findings were no different between non-ALI/ARDS patients and ALI/ARDS patients. CONCLUSION: Concerns regarding sedation requirements with use of lower V(T) are unfounded and should not preclude its use in patients with ALI/ARD

The collapse of protoplanetary clumps formed through disc instability: 3D simulations of the pre-dissociation phase

We present 3D smoothed particle hydrodynamics simulations of the collapse of clumps formed through gravitational instability in the outer part of a protoplanetary disc. The initial conditions are taken directly from a global disc simulation, and a realistic equation of state is used to follow the clumps as they contract over several orders of magnitude in density, approaching the molecular hydrogen dissociation stage. The effects of clump rotation, asymmetries, and radiative cooling are studied. Rotation provides support against fast collapse, but non-axisymmetric modes develop and efficiently transport angular momentum outward, forming a circumplanetary disc. This transport helps the clump reach the dynamical collapse phase, resulting from molecular hydrogen dissociation, on a thousand-year timescale, which is smaller than timescales predicted by some previous spherical 1D collapse models. Extrapolation to the threshold of the runaway hydrogen dissociation indicates that the collapse timescales can be shorter than inward migration timescales, suggesting that clumps could survive tidal disruption and deliver a proto-gas giant to distances of even a few AU from the central star.Comment: Accepted for publication in MNRA

The Impact of a Pulmonary-Artery-Catheter-Based Protocol on Fluid and Catecholamine Administration in Early Sepsis

Objective. The pulmonary artery catheter (PAC) remains topic of debate. Despite abundant data, it is of note that many trials did not incorporate a treatment protocol. Methods. We retrospectively evaluated fluid balances and catecholamine doses in septic patients after the introduction of a PAC-based treatment protocol in comparison to historic controls. Results. 2 × 70 patients were included. The first day the PAC group had a significantly higher positive fluid balance in comparison to controls (6.1 ± 2.6 versus 3.8 ± 2.4 litre, P < 0.001). After 7 days the cumulative fluid balance in the PAC group was significantly lower than in controls (9.4 ± 7.4 versus 13 ± 7.6 litre, P = 0.001). Maximum dose of norepinephrine was significantly higher in the PAC group. Compared to controls this was associated with a significant reduction in ventilator and ICU days. Conclusions. Introduction of a PAC-based treatment protocol in sepsis changed the administration of fluid and vasopressors significantly