Lactate and glucose metabolism in severe sepsis and cardiogenic shock

OBJECTIVE: To evaluate the relative importance of increased lactate production as opposed to decreased utilization in hyperlactatemic patients, as well as their relation to glucose metabolism. DESIGN: Prospective observational study. SETTING: Surgical intensive care unit of a university hospital. PATIENTS: Seven patients with severe sepsis or septic shock, seven patients with cardiogenic shock, and seven healthy volunteers. INTERVENTIONS: C-labeled sodium lactate was infused at 10 micromol/kg/min and then at 20 micromol/kg/min over 120 mins each. H-labeled glucose was infused throughout. MEASUREMENTS AND MAIN RESULTS: Baseline arterial lactate was higher in septic (3.2 +/- 2.6) and cardiogenic shock patients (2.8 +/- 0.4) than in healthy volunteers (0.9 +/- 0.20 mmol/L, p < .05). Lactate clearance, computed using pharmacokinetic calculations, was similar in septic, cardiogenic shock, and controls, respectively: 10.8 +/- 5.4, 9.6 +/- 2.1, and 12.0 +/- 2.6 mL/kg/min. Endogenous lactate production was determined as the initial lactate concentration multiplied by lactate clearance. It was markedly enhanced in the patients (septic 26.2 +/- 10.5; cardiogenic shock 26.6 +/- 5.1) compared with controls (11.2 +/- 2.7 micromol/kg/min, p < .01). C-lactate oxidation (septic 54 +/- 25; cardiogenic shock 43 +/- 16; controls 65 +/- 15% of a lactate load of 10 micromol/kg/min) and transformation of C-lactate into C-glucose were not different (respectively, 15 +/- 15, 9 +/- 18, and 10 +/- 7%). Endogenous glucose production was markedly increased in the patients (septic 14.8 +/- 1.8; cardiogenic shock 15.0 +/- 1.5) compared with controls (7.2 +/- 1.1 micromol/kg/min, p < .01) and was not influenced by lactate infusion. CONCLUSIONS: In patients suffering from septic or cardiogenic shock, hyperlactatemia was mainly related to increased production, whereas lactate clearance was similar to healthy subjects. Increased lactate production was concomitant to hyperglycemia and increased glucose turnover, suggesting that the latter substantially influences lactate metabolism during critical illness.     

Endothelial flow-mediated dilatation and exercise capacity in highly trained endurance athletes

Brachial artery ultrasound during reactive hyperemia is a noninvasive method of assessing peripheral endothelium-dependent vasodilatation. Aerobic exercise has the potential to improve local endothelial function. We sought to analyze the effects of regular aerobic training on brachial artery endothelial function in endurance athletes. We studied diameter and blood flow of the brachial artery in 32 endurance male athletes and 30 healthy male subjects. In the same subjects flow-mediated dilatation of the brachial artery was recorded by inducing an ischemia through a forearm arterial occluding cuff. Maximal oxygen consumption was significantly higher in the athletes group than in the controls (61.24 +/- 5.43 vs 44.49 +/- 2.68 ml/kg/min, p < 0.001). Flow-mediated dilatation of the brachial artery induced by forearm arterial occlusion in athletes was also higher than that of the control subjects (17.1 +/- 2.3 vs 11.2 +/- 1.7, p=0.002). Furthermore, there was an association between flow-mediated dilatation and VO2max (r=0.69, p < 0.001). Baseline measurements of the diameter and the blood flow volume of the brachial artery were similar in both groups. During reactive hyperemia period, the percent of the changes of endothelial diameters and flow were significantly higher in athletes than in controls. Higher flow-mediated dilatation levels in athletes reflect better vascular adaptation to habitual aerobic exercise.     

Endothelium-dependent vasodilation in the skin microcirculation of patients with septic shock

The evidence for endothelial dysfunction in sepsis is mostly restricted to animal models. We investigated endothelial function in the skin microcirculation of eight patients hospitalized for septic shock in an intensive care unit (ICU). All patients required adrenergic support. Twelve hemodynamically stable ICU patients without sepsis who did not receive any vasoactive medication were used as controls. The two groups were of similar age and sex ratio. For additional reference, 16 healthy, nonsmoking subjects matched for age and sex to the first two groups were also studied. The evaluation of endothelial function was based on the comparison of skin blood flow responses to iontophoretically applied acetylcholine (Ach, an endothelium-dependent vasodilator) and sodium nitroprusside (SNP, an endothelium-independent vasodilator). Skin blood flow was measured on the volar face of the forearm using laser Doppler imaging. Before application of Ach or SNP, the mean baseline skin blood flow was below 100 perfusion units (PU) in all subjects and did not differ between groups. The maximal increase in blood flow elicited by both agents was significantly depressed in the patients with sepsis (Ach: 167 +/- 63 PU; SNP: 138 +/- 34 PU, mean +/- SD) compared with the ICU control patients (Ach: 291 +/- 135 PU, P < 0.05; SNP: 261 +/- 121 PU, P < 0.01) and the healthy, nonsmoking groups (Ach: 336 +/- 98 PU, P < 0.01; SNP: 304 +/- 81 PU, P < 0.01). The ratio of responses to Ach and SNP did not significantly differ between groups (septic: 1.22 +/- 0.40; ICU control 1.18 +/- 0.46, healthy, nonsmoking 1.12 +/- 0.24, P = 0.86). Thus, sepsis was not associated with a selective depression of the endothelium-dependent response. These results suggest that the capacity of the endothelium to produce signals for vasorelaxation remains intact in the skin microcirculation of patients with septic shock.     

Nitric oxide indices in human septic shock

OBJECTIVES: To study the relation between nitrite, nitrate, nitrotyrosine, and nitrosothiols as NO indices in human septic shock. DESIGN: A prospective clinical study. SETTING: Intensive care units in a university hospital and a central county hospital. PATIENTS: Sixteen patients admitted for septic shock. Nine healthy volunteers served as controls. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients with septic shock had a hyperdynamic circulatory response and required infusion of at least two vasopressors to maintain systemic blood pressure. Four episodes of recurrent shock occurred in two patients. Heparinized plasma was collected once daily for analysis of NO indices. Peak plasma concentrations of nitrite + nitrate (NOx) were elevated in first episodes of septic shock; 144+/-39 microM vs. controls, 20+/-3 microM (p < .05). Peak plasma NOx concentrations in recurrent shocks were; 160+/-19 microM. Peak plasma concentrations of 3-nitrotyrosine (NT) were elevated in primary septic shock 102+/-19 pmol x mL(-1) vs. controls 14+/-6 pmol x mL(-1) (p < .05). Peak NT concentrations were 117+/-37 pmol x mL(-1) in recurrent septic shock. Peak plasma NT concentrations did not coincide with peak NOx concentrations in half of the episodes of septic shock. Plasma NT was elevated (59+/-15 pmol x mL(-1) vs. controls 14+/-6 pmol x mL(-1), p < .05) in patients with normal plasma NOx concentrations throughout septic shock. Plasma concentrations of nitrosothiols did not change during septic shock. CONCLUSIONS: Plasma concentrations of NOx and NT are elevated in primary episodes of septic shock and may also be elevated in secondary septic shock, but too few episodes of recurrent septic shock occurred to allow firm conclusions. Plasma concentrations of NT are elevated in patients with septic shock with normal plasma NOx concentrations, indicating that plasma concentrations of NOx may not always accurately reflect NO production. Reactive nitrogen species may be formed in septic shock, and measuring both NOx and NT may give a better indication of NO production in septic shock than NOx alone. Plasma levels of nitrosothiols did not change during septic shock.     

High-dose vasopressin is not superior to norepinephrine in septic shock

OBJECTIVE: We examined the effects of arginine vasopressin, when substituted for norepinephrine as a vasopressor in septic shock, on global and hepatosplanchnic hemodynamic and oxygen transport variables. DESIGN: Experimental study. SETTING: Intensive care unit. SUBJECTS: Twelve septic shock patients. INTERVENTIONS: Norepinephrine was replaced by vasopressin in a dose sufficient to keep mean arterial blood pressure constant. Blood flow, oxygen delivery, and oxygen consumption of the hepatosplanchnic region (calculated by a hepatic venous catheter technique using the Fick principle during continuous infusion of indocyanine green), global hemodynamics (by thermodilution), and gastric regional PCO2 gap (by air tonometry) were calculated during infusion of norepinephrine (mean, 0.56 microg.kg-1.min-1; range, 0.18-1.1 microg.kg-1.min-1) and again 2 hrs after replacement by vasopressin (mean, 0.47 IU/min; range, 0.06-1.8 IU/min). MEASUREMENTS AND MAIN RESULTS: Cardiac index decreased significantly from 3.8 +/- 1.3 to 3.0 +/- 1.1 L.min-1.m-2, heart rate decreased from 96 +/- 14 to 80 +/- 16 min-1 (p <.01), and global oxygen uptake decreased from 248 +/- 67 to 218 +/- 75 mL/min (p <.05). Absolute splanchnic blood flow tended to increase, although not significantly, whereas fractional splanchnic blood flow increased from 10.8 +/- 7.6 to 25.9 +/- 16.6% of cardiac output (p <.05). Gastric regional PCO2 gap increased from 17.5 +/- 26.6 to 36.5 +/- 26.6 mm Hg (p <.01). CONCLUSION: Vasopressin, in doses sufficient to replace the vasopressor norepinephrine, had mixed effects in septic shock patients. Hepatosplanchnic blood flow was preserved during substantial reduction in cardiac output. An increased gastric PCO2 gap suggests that the gut blood flow could have been redistributed to the disadvantage of the mucosa. Based on these limited data, it does not appear beneficial to directly replace norepinephrine with vasopressin in septic shock.     

End-tidal carbon dioxide as a noninvasive indicator of cardiac index during circulatory shock

OBJECTIVE: To document the relationships between cardiac index and end-tidal carbon dioxide tension (PetCO2 during diverse low-flow states of circulatory shock. DESIGN: Randomized, prospective, controlled studies on animal models of hemorrhagic, septic, and cardiogenic shock. SETTING: University-affiliated research laboratory. SUBJECTS: Sixteen anesthetized domestic pigs weighing 35-45 kg. INTERVENTIONS: Hemorrhagic shock was induced in five pigs by bleeding followed by reinfusion of shed blood. Septic shock was induced in five pigs by infusion of live Escherichia coli. Cardiogenic shock followed an interval of global myocardial ischemia after inducing and reversing ventricular fibrillation in six pigs. MEASUREMENTS AND MAIN RESULTS: PetCO2 was continuously measured. Cardiac index was measured intermittently by using conventional thermodilution techniques. Cardiac index was correlated with PetCO2 by polynomial regression and Bland-Altman analyses. PetCO2 was highly correlated with cardiac index during hemorrhagic shock (r2 = .69, p < .01), septic shock (r2 = .65, p < .01), and cardiogenic shock (r2 = .81, p < .01). PetCO2 predicted thermodilution cardiac index with bias of -11+/-27 (+/-2 SD) mL/min/kg during hemorrhagic shock, 1.3+/-20.4 (+/- 2 SD) mL/min/kg during septic shock, and -1+/-12 (+/-2 SD) mL/min/kg during cardiogenic shock. CONCLUSIONS: Cardiac output and PetCO2 were highly related in diverse experimental models of circulatory shock in which cardiac output was reduced by >40% of baseline values. Therefore, measurement of PetCO2 is a noninvasive alternative for continuous assessment of cardiac output during low-flow circulatory shock states of diverse causes.     

Evolution of lactate/pyruvate and arterial ketone body ratios in the early course of catecholamine-treated septic shock

OBJECTIVES: To measure arterial lactate/pyruvate (L/P) and arterial ketone body ratios as reflection of cytoplasmic and mitochondrial redox state at different stages of catecholamine-treated septic shock and compare them with normal and pathologic values obtained in patients in shock who have decreased oxygen transport (cardiogenic shock), and to assess the relationship between the time course of lactate, L/P ratio, and mortality in septic shock. DESIGN: Prospective, observational human study. SETTING: A university intensive care unit. PATIENTS: Sixty consecutive adult patients who developed septic shock and lactic acidosis requiring the administration of vasopressors. Twenty patients in the intensive care unit without shock, sepsis, and hypoxia and with normal lactate values and 10 patients with cardiogenic shock were also studied. MEASUREMENTS: Hemodynamic measurements, arterial and mixed venous blood gases, arterial lactate and pyruvate concentrations, and arterial ketone body ratio were measured within 4 hrs after the introduction of catecholamine and 24 hrs later. MAIN RESULTS: Fifteen patients (25%) died within the first 24 hrs of septic shock, and these early fatalities had a higher blood lactate (12.2+/-3 versus 4.6+/-1.3 mmol/L; p<.01) concentration and a higher L/P ratio (37+/-4 versus 20+/-1; p<.01) than those who died later. No difference was found for arterial ketone body ratio (0.41+/-0.1 versus 0.50+/-0.06). Forty-five patients survived >24 hrs including 25 survivors and 20 nonsurvivors. Although there was no difference between survivors and nonsurvivors in initial lactate concentration (4.1+/-0.4 and 4.6+/-0.3, respectively), L/P ratio (19+/-1 and 20+/-1, respectively), and arterial ketone body ratio (0.5+/-0.06 and 0.52+/-0.07, respectively), blood lactate and L/P ratio significantly decreased during the first 24 hrs in the survivors (2.8+/-0.4 and 14+/-1, respectively; p<.05). and were stable in the nonsurvivors (4+/-0.3 and 22+/-1, respectively) Although returning to normal values after 24 hrs in survivors and nonsurvivors, arterial ketone body ratio was higher in survivors (1.72+/-0.17 versus 1.09+/-0.15; p<.05). Lactate and L/P ratio were closely correlated (r2 = .8, p<.0001). In the cardiogenic shock group, lactate concentration was 4+/-1 mmol/L, L/P ratio was 40+/-6, and arterial ketone body ratio was 0.2+/-0.05. The mortality rate was 60%. CONCLUSIONS: The main result of the present study is that hemodynamically unstable patients with sepsis needing catecholamine therapy had a lactic acidosis with an elevated L/P ratio and a decreased arterial ketone body ratio, suggesting a decrease in cytoplasmic and mitochondrial redox state. The duration of lactic acidosis is associated with the development of multiple organ failure and death.     

Enterovirus infection as a risk factor of acute coronary syndrome and its complications

Antigens of enteroviruses were detected quantitatively in the modified complement-binding reaction in blood samples from 102 of the 208 (49%) patients with ACS, in coronary artery tissues from 23 of 24 and heart from 51 of 94 (54.3%) patients with MI who died from cardiogenic shock and/or cardiac rupture. The relative level of enterovirus antigen (RLEVA) in the blood of patients with MI complicated and uncomplicated by cardiogenic shock and/or cardiac rupture was 0.42 +/- 0.04 and 0.29 +/- 0.02 arbitrary units respectively (p = 0.032) compared with 0.21 +/- 0.07 in patients with unstable angina (UA) (p = 0.0001). RLEVA in patients with UA was significantly lower than in those with uncomplicated MI (p < 0.011). RLEVA in necrotized myocardial areas after death from cardiogenic shock (0.54 +/- 0.18) and/or cardiac rupture (0.46 +/- 0.15) was higher than outside MI zones (0.30 +/- 0.14 and 0.26 +/- 0.10 respectively) (p < 0.01). RLEVA in coronary vessels feeding the necrotic zones of patients with MI complicated by cardiogenic shock (0.44 +/- 0.18) was higher (p = 0.03) than in the vessel feeding tissues outside the MI zone (0.29 +/- 0.19). It is concluded that enterovirus infection is a factor of ACS; it is directly involved in its pathogenesis and promotes the development of cardiogenic shock and/or cardiac rupture.     

Effect of blood transfusion on oxygen consumption in pediatric septic shock

Treatment plans for pediatric septic shock advocate increasing oxygen consumption (VO2). Recent studies in septic shock indicate that improving oxygen delivery (DO2) by increasing blood flow will increase VO2. We prospectively examined the effect on VO2 of improving DO2 by increasing oxygen content (CO2) with blood transfusion in eight hemodynamically stable septic shock patients. Transfusion consisted of 8 to 10 ml/kg of packed RBC over 1 to 2 h. Hemodynamic and oxygen transport measurements were obtained before and after blood transfusion. Transfusion significantly (p less than .05) increased Hgb and Hct from 10.2 +/- 0.8 g/dl and 30 +/- 2% to 13.2 +/- 1.4 g/dl and 39 +/- 4%, respectively (mean +/- SD). DO2 significantly (p less than .05) increased after transfusion (599 +/- 65 to 818 +/- 189 ml/min.m2), but VO2 did not change (166 +/- 68 to 176 +/- 74 ml/min.m2; NS). In pediatric septic shock patients, increasing CO2 by blood transfusion may not increase VO2.     

Early circulating lymphocyte apoptosis in human septic shock is associated with poor outcome

The role of lymphocyte apoptosis in septic shock remains a controversial issue. Using Annexin V and flow cytometry analysis on freshly isolated cells, we evaluated circulating lymphocyte apoptosis in 23 septic shock, 25 sepsis without shock, 7 nonseptic critically ill, and 25 control patients. In patients with sepsis, we compared day 1 lymphocyte apoptosis (i.e., within 3 days of the onset of infection) with that observed 5-7 days after (day 6) according to shock state, mortality, and seventy factors. At day 1, patients in septic shock exhibited higher lymphocyte apoptosis than that present in controls (16.5% +/- 3.5% vs. 3% +/- 0.5%, respectively, P = 0.0001). At day 6, patients with sepsis without shock restored undamaged CD4+ T and CD8+ T lymphocyte counts, whereas patients in septic shock increased only CD4+ T cells. Similarly, survivors restored undamaged lymphocyte count at day 6 (+70%, P < 0.001), whereas nonsurvivors did not. Day 6 undamaged lymphocyte count negatively correlated with day 1 SAPS II, day 6 LOD score, mechanical ventilation, and ICU stay duration. We observed no apoptotic effect of septic shock plasma or septic shock circulating mononuclear cells on target lymphoid cell lines. We found no alteration in any death receptors Fas, TRAIL-R1, TRAIL-R2, or in their ligands on circulating blood cells. Catecholamines and interleukin 10 levels significantly increased in patients with septic shock, but did not correlate with apoptosis levels. We conclude that lymphocyte apoptosis is rapidly increased in blood of patients in septic shock and that lymphocyte apoptosis leads to a profound and persistent lymphopenia associated with poor outcome. These results suggest that lymphocyte apoptosis is one of the main components of human septic shock immune dysfunction and could be related more to microcirculatory disturbance than to circulating factors.     

Impaired vasodilation of forearm resistance vessels in hypercholesterolemic humans.

The effect of hypercholesterolemia on vascular function was studied in humans. To eliminate the potential confounding effects of atherosclerosis, vascular reactivity was measured in the forearm resistance vessels of 11 normal subjects (serum LDL cholesterol = 111 +/- 7 mg/dl) and 13 patients with hypercholesterolemia (serum LDL cholesterol = 211 +/- 19 mg/dl, P less than 0.05). Each subject received intrabrachial artery infusions of methacholine, which releases endothelium-derived relaxant factor, and nitroprusside which directly stimulates guanylate cyclase in vascular smooth muscle. Maximal vasodilatory potential was determined during reactive hyperemia. Vasoconstrictive responsiveness was examined during intra-arterial phenylephrine infusion. Forearm blood flow was determined by venous occlusion plethysmography. Basal forearm blood flow in normal and hypercholesterolemic subjects was comparable. Similarly, reactive hyperemic blood flow did not differ between the two groups. In contrast, the maximal forearm blood flow response to methacholine in hypercholesterolemic subjects was less than that observed in normal subjects. In addition, the forearm blood flow response to nitroprusside was less in hypercholesterolemic subjects. There was no difference in the forearm vasoconstrictive response to phenylephrine in the two groups. Thus, the vasodilator responses to methacholine and nitroprusside were blunted in patients with hypercholesterolemia. We conclude that in humans with hypercholesterolemia, there is a decreased effect of nitrovasodilators, including endothelium-derived relaxing factor, on the vascular smooth muscle of resistance vessels.     

High adenosine plasma concentration as a prognostic index for outcome in patients with septic shock

OBJECTIVE: Sepsis and septic shock are a common cause of mortality in critically ill patients. Many substances have been implicated in the pathophysiology of these syndromes. We postulated that adenosine may be implicated in the sepsis- or septic shock-induced blood pressure failure. Indeed, this nucleoside is a strong endogenous vasodilating agent released by endothelial cells and myocytes under circumstances of metabolic stress, such as during critical illness. DESIGN: A prospective, comparative observational study. SETTING: The adult intensive care unit of a tertiary care university hospital. PATIENTS: We measured adenosine plasma concentration (APC) in patients with severe sepsis (n = 11), in patients with septic shock (n = 14), in patients with hemorrhagic traumatic shock (n = 14), and in 12 healthy volunteers. APC was evaluated every 12 hrs over 3 days. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: At study entry, we found that APC was higher in patients with septic shock (mean +/- so = 8.4 +/-3.5 micromol/L) than in patients with hemorrhagic traumatic shock (1.1 +/- 0.6 micromol/L) and controls (0.8 +/- 0.3 micromol/L). Intermediate values (3.9 +/- 1.9 micromol/L) were found in patients with severe sepsis. APC in patients with traumatic shock did not differ from controls. In the course of the hospitalization, for both sepsis and septic shock patients, APC decreased significantly but remained higher than controls 72 hrs after entry into the study. In the septic shock group, APC was significantly higher in the nonsurvivor group (n = 6) than in the survivor group (n = 8), whatever the time of sample collection and assay. CONCLUSIONS: High adenosine plasma concentrations are found in patients with septic shock but not during traumatic shock, or in healthy volunteers. Intermediate values of circulating adenosine are found in patients with severe sepsis. APC may be a prognostic index for outcome in septic patients, with much higher values being found in nonsurvivors.     

Vitamin C affects thrombosis/ fibrinolysis system and reactive hyperemia in patients with type 2 diabetes and coronary artery disease

OBJECTIVE: To examine the effect of vitamin C on forearm vasodilatory response to reactive hyperemia and on plasma level of plasminogen activator inhibitor 1 (PAI-1), von Willebrand factor (vWF), tissue plasminogen activator (tPA), antithrombin III (ATIII), proteins C and S, and factors V (fV) and VII (fVII) in patients with both type 2 diabetes and CAD. RESEARCH DESIGN AND METHODS: A total of 39 patients with type 2 diabetes and CAD were divided into two groups and received vitamin C (2 g/day) or no antioxidant for 4 weeks. Forearm blood flow was determined using venous occlusion gauge-strain plethysmography at baseline and after treatment. Forearm vasodilatory response to reactive hyperemia (RH%) or nitrate (NTG%) was defined as the percent change of flow from baseline to the maximum flow during reactive hyperemia or after administration of nitrate, respectively. Biochemical markers were determined by enzyme-linked immunosorbent assay (ELISA) or other standard methods. RESULTS: RH% was significantly increased after treatment with vitamin C (from 62.4 +/- 7.2 to 83.1 +/- 9.3%, P = 0.024) but remained unaffected in the control group. Vitamin C decreased plasma levels of fV (from 143 +/- 5.4 to 123 +/- 6.03%, P = 0.038), vWF (from 133.5 +/- 14.5 to 109.5 +/- 11.4%, P = 0.016), and tPA (from 12.3 +/- 0.99 to 8.40 +/- 0.60 ng/ml, P = 0.001), whereas these levels remained unaffected in the control group. The changes in RH%, vWF, and tPA were significantly greater (P = 0.028, 0.036, and 0.007, respectively) in the vitamin C-treated group than in the control group. Levels of ATIII, proteins S and C, fVII, and PAI-1 remained unchanged in all groups. CONCLUSIONS: Short-term treatment with high doses of vitamin C improved RH% and decreased plasma levels of tPA and vWF in patients with type 2 diabetes and CAD.     

Terlipressin or norepinephrine in hyperdynamic septic shock: a prospective, randomized study

OBJECTIVE: To compare, in patients with hyperdynamic septic shock, the effects of norepinephrine or terlipressin on hemodynamic variables and renal function. DESIGN: Prospective, randomized, open-label study. SETTING: Intensive care unit of a university, tertiary, and referral center. PATIENTS: Twenty adult patients with hyperdynamic septic shock, after fluid resuscitation. INTERVENTIONS: Patients were randomized to receive norepinephrine or terlipressin. Global hemodynamic variables, oxygen consumption, urine flow, creatinine clearance, and arterial blood lactate levels were measured. MEASUREMENTS AND MAIN RESULTS: Mean arterial pressure, systemic vascular resistance, pulmonary vascular resistance, and left and right ventricular stroke work were significantly increased with both drugs. With terlipressin, but not with norepinephrine, a significant decrease in heart rate (from 113 +/- 17 to 104 +/- 11 beats.min(-1), p < .01) and cardiac index (from 5.1 +/- 1.7 to 4.2 +/- 1.6 L.min(-1).m(-2)) was observed, with no change in stroke volume. Oxygen delivery index (from 784 +/- 131 to 701 +/- 92 mL.min(-1).m(-2)) and consumption index (from 244 +/- 69 to 210 +/- 54 mL.min(-1).m(-2)) were significantly decreased with terlipressin, but not with norepinephrine. Blood lactate concentrations were significantly decreased with both drugs. Urine flow and creatinine clearance were increased with both drugs. CONCLUSIONS: In patients with hyperdynamic septic shock, both norepinephrine and terlipressin were effective to raise mean arterial blood pressure. With terlipressin, but not norepinephrine, the improvement in blood pressure was achieved at the expense of cardiac index and oxygen consumption, which were significantly decreased. Renal function was improved with both drugs. In further studies, alternative strategies to maintain cardiac index should be explored, such as a synergy between low-dose terlipressin and dobutamine.     

Role of interleukin-10 in monocyte hyporesponsiveness associated with septic shock

OBJECTIVES: The purpose of this study was to examine the pattern of tumor necrosis factor (TNF)-alpha and interleukin (IL)-10 release in endotoxin-stimulated septic monocytes and to determine the role of IL-10 and transforming growth factor (TGF)-beta in monocyte hyporesponsiveness during septic shock. DESIGN: Monocytes isolated from ten healthy controls and ten patients with septic shock were incubated with endotoxin and cytokine release was assessed. Next, normal monocytes were incubated with either normal or septic serum and stimulated with endotoxin. Finally, normal monocytes were incubated with septic serum either with anti-IL-10 antibodies or anti-TGF-beta antibodies and then stimulated with endotoxin. MEASUREMENTS: TNF-alpha, IL-10, and TGF-beta levels were measured in the serum and in culture supernatants by enzyme-linked immunosorbent assay. SETTING: Research laboratory. MAIN RESULTS: IL-10 and TNF-alpha levels were significantly increased in septic serum, whereas TGF-beta levels were not different from controls. Normal monocytes increased TNF-alpha and IL-10 release in response to endotoxin. In contrast, septic monocyte TNF-alpha release was attenuated in response to endotoxin (1.8 +/- 0.5 vs. 1.0 +/- 0.4 ng/mL, stimulated vs. baseline), whereas IL-10 release increased significantly from baseline (173 +/- 91 vs. 8 +/- 4 pg/mL, stimulated vs. baseline). Incubation of normal monocytes with septic serum attenuated TNF-alpha release in response to endotoxin (32% +/- 8% of normal serum; p < .01), whereas IL-10 release was increased (285% +/- 84% of normal serum; p < .05). When normal monocytes were incubated with septic serum combined with anti-IL-10 antibodies, TNF-alpha release increased significantly to 75% +/- 17% of normal serum (p < .05 vs. septic serum alone). Incubation of normal monocytes with anti-TGF-beta antibodies did not significantly affect either TNF-alpha or IL-10 release in response to endotoxin. CONCLUSION: Monocytes from patients with septic shock exhibit persistent IL-10 release at a time when TNF-alpha release is downregulated. The continued release of IL-10 may contribute to impairment of monocyte proinflammatory cytokine release and the development of immune dysfunction in septic shock.     

Skin reactive hyperemia in diabetic patients. A study by laser Doppler flowmetry.

OBJECTIVE: To assess whether laser Doppler flowmetry could detect differences in the cutaneous response to postischemic reactive hyperemia between patients with non-insulin-dependent diabetes mellitus (NIDDM) and nondiabetic controls and among subgroups of NIDDM patients. RESEARCH DESIGN AND METHODS: We measured the cutaneous blood flow on the forearms during the postischemic reactive hyperemia test in diabetic patients and nondiabetic controls. Subjects were 25 patients with NIDDM from the outpatient clinics of dermatology, ophthalmology, and endocrinology and 25 nondiabetic volunteers matched for sex and age. Of the patients with NIDDM, 14 had proliferative retinopathy, and 13 were obese. Cutaneous postischemic reactive hyperemia test monitored by measuring the cutaneous blood flow with laser Doppler flowmetry was used. Peak blood flow (P) after arterial occlusion, the time required to reach this peak (Tp) and the ratio (K) between these two quantities (K = P/Tp) were measured. RESULTS: In diabetic patients, P was significantly lower (P less than 0.02) than in nondiabetic control subjects. In diabetic patients with proliferative retinopathy, K was lower (P less than 0.05) than in diabetic patients without retinopathy. Diabetic patients with a body mass index (BMI; wt/ht2) less than 25 kg/m2 had a longer Tp (P less than 0.002), whereas the control group BMI did not affect this parameter. The combination of retinopathy and BMI less than 25 gave the longest Tp values (P less than 0.0001). CONCLUSIONS: Postischemic hyperemia tests in diabetic patients reveal cutaneous microcirculatory changes in the forearm (lower P). Advanced retinopathy is associated with functional disturbances (lower K), especially when combined with a low BMI (less than 25; longer Tp).     

Association between a genomic polymorphism within the CD14 locus and septic shock susceptibility and mortality rate

OBJECTIVE: Genetic differences in immune responses may affect susceptibility to and outcome of septic shock. CD14 seems to be an important part of the innate immune system, initiating antimicrobial response. We evaluated the frequency of a recently discovered CD14 promoter gene polymorphism (C to T transition at base pair -159) among patients with septic shock compared with those in a control group. DESIGN: Multiple-center study. SETTING: Hospital research department. PATIENTS: Ninety consecutive white patients with septic shock were included. The control group consisted of 122 age- and gender-matched white subjects. INTERVENTIONS: In both groups, the C-159T CD14 promoter genetic polymorphism was determined by using polymerase chain reaction and subsequent Hae III restriction enzyme digestion of the polymerase chain reaction products. MEASUREMENTS AND MAIN RESULTS: The C-159T polymorphism and the TT genotype were significantly overrepresented among septic shock patients compared with controls. Within the septic shock group, the mortality of patients with TT genotype (71%) was significantly higher than in patients with other genotypes (48%; Pearson chi-square, p =.008). In a multiple logistic regression model, the TT genotype was independently associated with an increased relative risk of death (odds ratio, 5.30; 95% confidence interval, 1.20-22.50, p =.02). CONCLUSIONS: The C-159T polymorphism affects susceptibility to septic shock and seems to be a new genetic risk factor for death.     

Linear and nonlinear analysis of hemodynamic signals during sepsis and septic shock

OBJECTIVE: Neuroautonomic modulation of heart rate (HR) and blood pressure were assessed in sepsis or septic shock. We hypothesized that these metrics would be diminished in pediatric patients with sepsis and septic shock, indicating uncoupling of the autonomic and cardiovascular systems. DESIGN: Prospective case series. SETTING: Pediatric intensive care unit in a tertiary care children's hospital. PATIENTS: Thirty pediatric patients with sepsis or septic shock. INTERVENTIONS: None. MEASURES AND MAIN RESULTS: Metrics used included power spectral analysis, a linear frequency domain measure, and detrended fluctuation analysis, a nonlinear technique that assesses the degree of long-range correlation in HR or blood pressure. We found decreased low-frequency (2.68 +/- 0.24 vs. 3.37 +/- 0.17 [SEM] bpm2; p = .03) and high-frequency HR power (2.18 +/- 0.14 vs. 2.79 +/- 0.23 bpm2; p = .04) and increased detrended fluctuation analysis scaling exponent (1.22 +/- 0.06 vs. 1.00 +/- 0.07 bpm2; p = .02) in sepsis vs. shock patients, respectively. Compared with sepsis or shock, recovery was associated with increases in low-frequency (3.61 +/- 0.15 vs. 3.05 +/- 0.19 bpm2; p < .0001) and high-frequency HR power (3.11 +/- 0.15 vs. 2.50 +/- 0.22 bpm2; p < .0001). CONCLUSIONS: We conclude that uncoupling of the autonomic and cardiovascular systems occurs over both short- and long-range time scales during sepsis, and the degree of uncoupling may help differentiate between sepsis, septic shock, and recovery states.