Shock-Induced Endothelial Dysfunction is Present in Patients With Occult Hypoperfusion After Trauma

BACKGROUND

Shock-induced endothelial dysfunction, evidenced by elevated soluble thrombomodulin (sTM) and syndecan-1 (Syn-1), is associated with poor outcomes after trauma. The association of endothelial dysfunction and overt shock has been demonstrated; it is unknown if hypoperfusion in the setting of normal vital signs (occult hypoperfusion [OH]) is associated with endothelial dysfunction. We hypothesized that sTM and Syn-1 would be elevated in patients with OH when compared to patients with normal perfusion.

METHODS

A single-center study of patients requiring highest-level trauma activation (2012-2016) was performed. Trauma bay arrival plasma Syn-1 and sTM were measured by enzyme-linked immunosorbent assay. Shock was defined as systolic blood pressure (SBP) <90 mm Hg or heart rate (HR) ≥120 bpm. OH was defined as SBP ≥ 90, HR < 120, and base excess (BE) ≤-3. Normal perfusion was assigned to all others. Univariate and multivariable analyses were performed.

RESULTS

Of 520 patients, 35% presented with OH and 26% with shock. Demographics were similar between groups. Patients with normal perfusion had the lowest Syn-1 and sTM, while patients with OH and shock had elevated levels. OH was associated with increased sTM by 0.97 ng/mL (95% CI 0.39-1.57, p = 0.001) and Syn-1 by 14.3 ng/mL (95% CI -1.5 to 30.2, p = 0.08). Furthermore, shock was associated with increased sTM by 0.64 (95% CI 0.02-1.30, p = 0.04) and with increased Syn-1 by 23.6 ng/mL (95% CI 6.2-41.1, p = 0.008).

CONCLUSIONS

Arrival OH was associated with elevated sTM and Syn-1, indicating endothelial dysfunction. Treatments aiming to stabilize the endothelium may be beneficial for injured patients with evidence of hypoperfusion, regardless of vital signs.

Good Platelets Gone Bad: The Effects of Trauma Patient Plasma on Healthy Platelet Aggregation

BACKGROUND

Altered postinjury platelet behavior is recognized in the pathophysiology of trauma-induced coagulopathy (TIC), but the mechanisms remain largely undefined. Studies suggest that soluble factors released by injury may inhibit signaling pathways and induce structural changes in circulating platelets. Given this, we sought to examine the impact of treating healthy platelets with plasma from injured patients. We hypothesized that healthy platelets treated ex-vivo with plasma from injured patients with shock would impair platelet aggregation, while treatment with plasma from injured patients with significant injury burden, but without shock, would enhance platelet aggregation.

METHODS

Plasma samples were isolated from injured patients (pretransfusion) and healthy donors at a Level I trauma center and stored at -80°C. Plasma samples from four separate patients in each of the following stratified clinical groups were used: mild injury/no shock (injury severity score [ISS] 2-15, base excess [BE]>-6), mild injury/with shock (ISS 2-15, BE≤-6), severe injury/no shock (ISS>25, BE>-6), severe injury/with shock (ISS>25, BE≤-6), minimal injury (ISS 0/1, BE>-6), and healthy. Platelets were isolated from three healthy adult males and were treated with plasma for 30 min. Aggregation was stimulated with a thrombin receptor agonist and measured via multiple-electrode platelet aggregometry. Data were normalized to HEPES Tyrode's (HT) buffer-only treated platelets. Associations of plasma treatment groups with platelet aggregation measures were tested with Mann-Whitney U tests.

RESULTS

Platelets treated with plasma from patients with shock (regardless of degree of injury) had significantly impaired thrombin-stimulated aggregation compared with platelets treated with plasma from patients without shock (P = 0.002). Conversely, platelets treated with plasma from patients with severe injury, but without shock, had amplified thrombin-stimulated aggregation (P = 0.030).

CONCLUSION

Shock-mediated soluble factors impair platelet aggregation, and tissue injury-mediated soluble factors amplify platelet aggregation. Future characterization of these soluble factors will support development of novel treatments of TIC.

Prognostic value of serial lactate levels in septic patients with and without shock

To analyze the prognostic value of lactate levels for day-7 and in-hospital mortality, in septic patients with and without shock. In the period November 2011-December 2016, we enrolled 268 patients, admitted to our High-Dependency Unit with a diagnosis of sepsis. Lactate dosage was performed at ED-HDU admission (T0), after 2 h (T2), 6 h (T6) and 24 h (T24); lactate clearance was calculated at T2 and T6 [T2: ((LAC T0-LAC T2/LAC T0)*100)]; T6: [(LAC T0-LAC T6/LAC T0)*100]. The end-points were day-7 and in-hospital mortality. At every evaluation, the lactate level was higher in patients with shock than in those without (T0 3.8 ± 3.8 vs 2.4 ± 2.1; T6 2.9 ± 3.2 vs 1.6 ± 1.1; T24 3.0 ± 4.4 vs 1.4 ± 0.9 meq/L, all p < 0.001). Among patients with shock, an analysis for repeated measures confirmed a more marked lactate level reduction in survivors compared with non-survivors, both by day-7 and in-hospital mortality (p = 0.057 and p = 0.006). A Kaplan-MeIer analysis confirmed a significantly better day-7 survival in patients with T6 (with shock 86% vs 70%; without shock 93% vs 82, all p < 0.05) and T24 (with shock 86% vs 70%; without shock 93% vs 82, all p < 0.05) lactate ≤ 2 meq/L, compared with patients with higher levels. A T6 lactate clearance > 10% was more frequent among in-hospital survivors in the whole study population (57% vs 39%) and in patients with shock (74% vs 46%, all p < 0.05). Higher lactate levels and decreased clearance were associated with an increased short-term and intermediate-term mortality regardless of the presence of shock.

The effects of passive leg raising may be detected by the plethysmographic oxygen saturation signal in critically ill patients

BACKGROUND

A passive leg raising (PLR) test is positive if the cardiac index (CI) increased by > 10%, but it requires a direct measurement of CI. On the oxygen saturation plethysmographic signal, the perfusion index (PI) is the ratio between the pulsatile and the non-pulsatile portions. We hypothesised that the changes in PI could predict a positive PLR test and thus preload responsiveness in a totally non-invasive way.

METHODS

In patients with acute circulatory failure, we measured PI (Radical-7) and CI (PiCCO2) before and during a PLR test and, if decided, before and after volume expansion (500-mL saline).

RESULTS

Three patients were excluded because the plethysmography signal was absent and 3 other ones because it was unstable. Eventually, 72 patients were analysed. In 34 patients with a positive PLR test (increase in CI ≥ 10%), CI and PI increased during PLR by 21 ± 10% and 54 ± 53%, respectively. In the 38 patients with a negative PLR test, PI did not significantly change during PLR. In 26 patients in whom volume expansion was performed, CI and PI increased by 28 ± 14% and 53 ± 63%, respectively. The correlation between the PI and CI changes for all interventions was significant (r = 0.64, p < 0.001). During the PLR test, if PI increased by > 9%, a positive response of CI (≥ 10%) was diagnosed with a sensitivity of 91 (76-98%) and a specificity of 79 (63-90%) (area under the receiver operating characteristics curve 0.89 (0.80-0.95), p < 0.0001).

CONCLUSION

An increase in PI during PLR by 9% accurately detects a positive response of the PLR test.

TRIAL REGISTRATION

ID RCB 2016-A00959-42. Registered 27 June 2016.

The new bedside ROCky score to predict the complications in patients with intermediate-risk pulmonary embolism

OBJECTIVE

Pulmonary embolism (PE) remains one of the leading causes of mortality among cardiovascular diseases. We aimed at investigating risk factors of PE complications in patients with intermediate risk and integrate them into a simple model for its' bedside prediction.

METHODS

Among 173 patients with PE, 136 were classified as high or intermediate risk. Patients were retrospectively divided into groups of complicated (n = 44) or uncomplicated (n = 92) course. Study endpoints: obstructive shock, recurrent PE, needs for resuscitation/thrombolysis/hemodynamic support and death during 30 days.

RESULTS

Predictors of PE complications were: chronic heart failure, diabetes mellitus (DM), atrial fibrillation, permanent risk factor of venous thromboembolism, syncope, positive heart-type fatty acid binding protein (hFABP), positive troponin I, heart rate (HR) ≥ 110 bpm, systolic blood pressure (SBP) ≤ 100 mmHg, creatinine clearance ≤ 70 ml/min. Multivariate logistic regression analysis was used to model a simple predictive score named ROCky (Risk of Complications): HR ≥ 110 bpm (1.5 points), SBP ≤ 100 mmHg (2.5 points), positive hFABP (2 points) and presence of DM (2.5 points). The AUROC of this model was 0.89 to predict any complication, 0.83 for obstructive shock and 0.92 for death from any cause; the optimal cut-off scores for any complication was ≥2.5 points, ≥3.5 for obstructive shock and ≥4.5 points for death within 30 days.

CONCLUSION

hFABP, tachycardia, hypotension and DM were identified as the major independent determinants of complications development in patients with pulmonary embolism and may be used in combination as the bedside simple predictive ROCky score for early risk stratification in intermediate-risk group.

Management of pulmonary embolism after recent intracranial hemorrhage: A case report

RATIONALE

Venous thromboembolism may result from prolong immobilization following intracerebral hemorrhage. Massive pulmonary embolism with associated right heart failure is life-threatening, requiring treatment with anticoagulants or even thrombolytic agents. However, these drugs are contraindicated after a recent hemorrhagic episode, as they may induce further hemorrhage. There are no guidelines for treatment in these circumstances.

PATIENT CONCERNS

A 57-year-old man experienced massive pulmonary embolism and shock 18 days after an intracerebral hemorrhage.

DIAGNOSES

Tachycardia and high D-dimer (21.27 mg/L fibrinogen-equivalent units) were noted. Chest computed tomography showed bilateral pulmonary trunk embolism.

INTERVENTIONS

Heparinization were used and activated partial thromboplastin time therapeutic range was 50 to 70 seconds. Fortunately, shock status and shortness of breath improved two days later. Continuing high dose Rivaroxaban was administrated for three weeks.

OUTCOMES

There was no recurrent intracranial hemorrhage (ICH) following treatment for three-weeks with high-dose and one-year with standard dose of rivaroxaban. This report presents a treatment option in the management of these difficult clinical situations.

LESSONS

The combination of unfractionated heparin infusion and continuing non-Vitamin K antagonist oral anticoagulants use could manage life-threatening pulmonary embolism following recent ICH. Theoretically, the use of NOAC is a safer strategy if the patient with previous history of major ICH.

[Value of arterial blood lactic acid in the evaluation of disease severity and prognosis in neonatal shock]

OBJECTIVE

To evaluate the value of blood lactic acid (BLA) as a predictor for the severity and prognosis of neonatal shock.

METHODS

A total of 326 neonates with shock were enrolled and divided into three groups based on the severity, namely mild group (n=147), moderate group (n=105), and severe group (n=74). BLA level was measured during and early after (about 6 hours later) fluid resuscitation, and lactate clearance rate (LCR) was calculated. The receiver operating characteristic (ROC) curve was applied to evaluate the predictive value of BLA in neonatal shock.

RESULTS

BLA level was high in all subjects prior to treatment, and was highest in the severe group and lowest in the mild group (P<0.01). BLA level was significantly higher among patients with septic shock than among those with hypovolemic, cardiogenic, and asphyxiating shock (P<0.05). BLA level was significantly reduced in patients in recovery after treatment (P<0.05). Mortality was significantly lower in patients with BLA level ≤4 mmol/L or LCR ≥10% than in those with BLA level >4 mmol/L or LCR <10% (P<0.01). BLA at 11.15 mmol/L had 100% sensitivity and 96.8% specificity in predicting severe shock. BLA at 10.65 mmol/L had 88.9% sensitivity and 74.1% specificity in predicting the prognosis (survival or dead) of newborns with shock.

CONCLUSIONS

In neonates with shock, arterial BLA level increases as the disease severity increases and is associated with prognosis, so it is a useful predictor of the severity and prognosis of neonatal shock.

Hyperdehydroepiandrosterone in neonates with hypoxic ischemic encephalopathy and circulatory collapse

BACKGROUND

Circulatory collapse is a very common complication of the critical illnesses in neonates including neonates with hypoxic ischemic encephalopathy; it can be the end result and cause of death of several conditions. Often, despite treatment with fluid resuscitation and vasopressor agents, circulatory collapse persist, and blood pressure can remain critically low, compromising adequate blood flow to vital organs and brain. Low blood pressure has been associated with increased mortality.

METHOD

To investigate adrenal function in newborn infants who suffer from circulatory collapse during hypoxic ischemic encephalopathy. A total of 30 infants were analyzed in the study: 15 neonates in group A (neonates had hypoxic ischemic encephalopathy with vasopressor resistant hypotension) and 15 neonates in group B (neonates with hypoxic ischemic encephalopathy without vasopressor resistant hypotension). All the studied patients were subjected to history, examinations and laboratory investigation including serum cortisol concentrations and cortisol precursor's levels.

RESULTS

The cortisol concentrations did not differ significantly between the two groups: (12.9 ± 4.3) μg/dL and (12.1 ± 2.4) μg/dL in group A and group B, respectively. There are highly significant differences between groups A and B regarding Dehydroepiandrosterone (342.1 ± 101.3) μg/dL, (33.4 ± 16.5) μg/dL, respectively.

CONCLUSION

In this study, we noticed that cortisol concentrations did not differ between both groups in contrast to the expectation that neonates with critical illnesses should have higher cortisol concentrations than normal neonates. However, the marked increase in dehydroepiandrosterone DHEA may cause decrease cortisol function, so those neonates having accumulation of dehydroepiandrosterone may suffer from manifestation of adrenal insufficiency and vasopressor resistant hypotension in spite of normal cortisol level.

Defining predictors of mortality in pediatric trauma patients

BACKGROUND

The aim of this study was to describe our cohort of pediatric trauma patients and to analyze their physiological data. The intention was to highlight the difficulty in using systolic blood pressure (SBP) readings in this population and to investigate the role of base excess (BE) in predicting clinical outcomes in pediatric trauma patien.

METHOD

The Pietermaritzburg Metropolitan Trauma Service (PMTS) maintains a prospective digital trauma registry, and all pediatric trauma patients admitted to the service for the period January 2012 - July 2016 were included.

RESULTS

Out of an original dataset of 1239 pediatric trauma patients admitted to the emergency departments of the PMTS, 26 elective patients and 216 patients with missing SBP were excluded to leave a sample size of 997 patients. The majority of the sample was male accounting for 669 patients (67.2 %) with 327 females (32.8%) and 1 (0.1%) missing data. The mean age (SD) was 7.7 years (3.9) and the median age (IQR) was 8 years (5 - 11). There were 58 children < 2 years of age, 177 between the age of 2 to < 5 years of age, 402 between 5 to < 10 years of age and 360 between 10 and < 15 years of age. The predominant mechanism of injury was blunt trauma (78.4% or 782/997). Penetrating trauma accounted for 11.0% of cases (110/997). The mean systolic BP (SD) across the whole cohort was 110.1 mm Hg (16.9) and the median systolic BP (IQR) was 110 mm Hg (100-119). Mortality rate remains low and then precipitously increases below a SBP of 93 mm Hg in children older than 2 and below 89 mm Hg in children younger than 2. This suggests that a SBP of 93 mm Hg or less in children older than 2 and 89 mm Hg or less in children under 2 years is clinically significant. Similarly, as BE decreased, the mortality risk also increased prominently.

CONCLUSION

This study has used a previously described methodology based on large developed world trauma databases and confirms the current thinking that SBP is a late marker and thus not useful in the pediatric population and a better system/ approach is needed. The use of BE in conjunction with SBP may be a more useful means of identifying shock.

Cardio-haemodynamic assessment and venous lactate in severe dengue: Relationship with recurrent shock and respiratory distress

Background

Dengue can cause plasma leakage that may lead to dengue shock syndrome (DSS). In approximately 30% of DSS cases, recurrent episodes of shock occur. These patients have a higher risk of fluid overload, respiratory distress and poor outcomes. We investigated the association of echocardiographically-derived cardiac function and intravascular volume parameters plus lactate levels, with the outcomes of recurrent shock and respiratory distress in severe dengue.

Methods/Principle findings

We performed a prospective observational study in Paediatric and adult ICU, at the Hospital for Tropical Diseases (HTD), Ho Chi Minh City, Vietnam. Patients with dengue were enrolled within 12 hours of admission to paediatric or adult ICU. A haemodynamic assessment and portable echocardiograms were carried out daily for 5 days from enrolment and all interventions recorded.

102 patients were enrolled; 22 patients did not develop DSS, 48 had a single episode of shock and 32 had recurrent shock. Patients with recurrent shock had a higher enrolment pulse than those with 1 episode or no shock (median: 114 vs. 100 vs. 100 b/min, P = 0.002), significantly lower Stroke Volume Index (SVI), (median: 21.6 vs. 22.8 vs. 26.8mls/m², P<0.001) and higher lactate levels (4.2 vs. 2.9 vs. 2.2 mmol/l, P = 0.001). Higher SVI and worse left ventricular function (higher Left Myocardial Performance Index) on study days 3–5 was associated with the secondary endpoint of respiratory distress. There was an association between the total IV fluid administered during the ICU admission and respiratory distress (OR: 1.03, 95% CI 1.01–1.06, P = 0.001). Admission lactate levels predicted patients who subsequently developed recurrent shock (P = 0.004), and correlated positively with the total IV fluid volume received (rho: 0.323, P = 0.001) and also with admission ALT (rho: 0.764, P<0.001) and AST (rho: 0.773, P<0.001).

Conclusions/Significance

Echo-derived intravascular volume assessment and venous lactate levels can help identify dengue patients at high risk of recurrent shock and respiratory distress in ICU. These findings may serve to, not only assist in the management of DSS patients, but also these haemodynamic endpoints could be used in future dengue fluid intervention trials.

Dengue is a viral illness that can lead to severe and potentially fatal complications. The most common complication is fluid leakage from blood vessels, which can cause low blood pressure or dengue shock syndrome (DSS). The majority of patients recover with simple intravenous fluid replacement, however in approximately 30% of DSS cases, recurrent episodes of shock occur, and these patients have a higher risk of fluid overload, respiratory distress and death. We investigated whether using portable echocardiograms (Echo) in the intensive care unit (ICU) to assess cardiac function and intravascular volume parameters as well as blood lactate levels, can help identify these patients. We found patients who developed recurrent shock had higher heart rates and lower Stroke Volume Index (SVI), and higher lactate levels at enrolment than those with 1 episode or no shock. Higher SVI and worse cardiac function after 3 days in ICU was associated with respiratory distress. Admission lactate levels predicted patients who subsequently developed recurrent shock and correlated positively with the total IV fluid volume received. These results demonstrate that Echo-derived intravascular volume assessment and venous lactate levels can help identify dengue patients at high risk of poor outcomes in the ICU, and could assist in the management of severe dengue.

Clinical significance of the neutrophil-lymphocyte ratio as an early predictive marker for adverse outcomes in patients with acute pancreatitis

AIM

To investigated the prognostic value of the neutrophil-lymphocyte ratio (NLR) in patients with acute pancreatitis and determined an optimal cut-off value for the prediction of adverse outcomes in these patients.

METHODS

We retrospectively analyzed 490 patients with acute pancreatitis diagnosed between March 2007 and December 2012. NLRs were calculated at admission and 24, 48, and 72 h after admission. Patients were grouped according to acute pancreatitis severity and organ failure occurrence, and a comparative analysis was performed to compare the NLR between groups.

RESULTS

Among the 490 patients, 70 had severe acute pancreatitis with 31 experiencing organ failure. The severe acute pancreatitis group had a significantly higher NLR than the mild acute pancreatitis group on all 4 d (median, 6.14, 6.71, 5.70, and 4.00 vs 4.74, 4.47, 3.20, and 3.30, respectively, P < 0.05). The organ failure group had a significantly higher NLR than the group without organ failure on all 4 d (median, 7.09, 6.72, 6.27, and 6.24 vs 4.85, 4.49, 3.35, and 2.34, respectively, P < 0.05). The optimal cut-off value for baseline NLR was 4.76 in predicting severity and 4.88 in predicting organ failure in acute pancreatitis.

CONCLUSION

Elevated baseline NLR correlates with severe acute pancreatitis and organ failure.

Exercise-Associated Collapse: Is Hyponatremia in Our Head?

Exercise-associated hyponatremia (EAH) is one of the most common causes of exercise-associated collapse. The primary pathogenesis of EAH is largely the result of excessive fluid intake but is influenced by other factors, including hormonal abnormalities (ie, inappropriate arginine vasopressin secretion), renal abnormalities, and mobilization of sodium stores. Early recognition of EAH is crucial to appropriate treatment, because symptoms are varied and may be confused with other causes of exercise-associated collapse. Onsite testing of [Na+] will confirm the diagnosis but is not always available. Rapid treatment of EAH will depend upon the type and severity of symptoms. Treatment protocols range from fluid restriction or oral hypertonic fluids for mild symptoms to intravenous hypertonic fluids for more severe symptoms. Preventative strategies should emphasize fluid consumption based on thirst and athlete/coach/staff education regarding proper hydration practices.

Donor preoperative oxygen delivery and post-extubation hypoxia impact donation after circulatory death hypoxic cholangiopathy

AIM: To evaluate donation after circulatory death (DCD) orthotopic liver transplant outcomes [hypoxic cholangiopathy (HC) and patient/graft survival] and donor risk-conditions.

METHODS: From 2003-2013, 45 DCD donor transplants were performed. Predonation physiologic data from UNOS DonorNet included preoperative systolic and diastolic blood pressure, heart rate, pH, SpO₂, PaO₂, FiO₂, and hemoglobin. Mean arterial blood pressure was computed from the systolic and diastolic blood pressures. Donor preoperative arterial O₂ content was computed as [hemoglobin (gm/dL) × 1.37 (mL O₂/gm) × SpO₂%) + (0.003 × PaO₂)]. The amount of preoperative donor red blood cell transfusions given and vasopressor use during the intensive care unit stay were documented. Donors who were transfused ≥ 1 unit of red-cells or received ≥ 2 vasopressors in the preoperative period were categorized as the red-cell/multi-pressor group. Following withdrawal of life support, donor ischemia time was computed as the number-of-minutes from onset of diastolic blood pressure < 60 mmHg until aortic cross clamping. Donor hypoxemia time was the number-of-minutes from onset of pulse oximetry < 80% until clamping. Donor hypoxia score was (ischemia time + hypoxemia time) ÷ donor preoperative hemoglobin.

RESULTS: The 1, 3, and 5 year graft and patient survival rates were 83%, 77%, 60%; and 92%, 84%, and 72%, respectively. HC occurred in 49% with 16% requiring retransplant. HC occurred in donors with increased age (33.0 ± 10.6 years vs 25.6 ± 8.4 years, P = 0.014), less preoperative multiple vasopressors or red-cell transfusion (9.5% vs 54.6%, P = 0.002), lower preoperative hemoglobin (10.7 ± 2.2 gm/dL vs 12.3 ± 2.1 gm/dL, P = 0.017), lower preoperative arterial oxygen content (14.8 ± 2.8 mL O₂/100 mL blood vs 16.8 ± 3.3 mL O₂/100 mL blood, P = 0.049), greater hypoxia score >2.0 (69.6% vs 25.0%, P = 0.006), and increased preoperative mean arterial pressure (92.7 ± 16.2 mmHg vs 83.8 ± 18.5 mmHg, P = 0.10). HC was independently associated with age, multi-pressor/red-cell transfusion status, arterial oxygen content, hypoxia score, and mean arterial pressure (r² = 0.6197). The transplantation rate was greater for the later period with more liberal donor selection [era 2 (7.1/year)], compared to our early experience [era 1 (2.5/year)]. HC occurred in 63.0% during era 2 and in 29.4% during era 1 (P = 0.03). Era 2 donors had longer times for extubation-to-asystole (14.4 ± 4.7 m vs 9.3 ± 4.5 m, P = 0.001), ischemia (13.9 ± 5.9 m vs 9.7 ± 5.6 m, P = 0.03), and hypoxemia (16.0 ± 5.1 m vs 11.1 ± 6.7 m, P = 0.013) and a higher hypoxia score > 2.0 rate (73.1% vs 28.6%, P = 0.006).

CONCLUSION: Easily measured donor indices, including a hypoxia score, provide an objective measure of DCD liver transplantation risk for recipient HC. Donor selection criteria influence HC rates.

Increased Plasma Levels of Heparin-Binding Protein on Admission to Intensive Care Are Associated with Respiratory and Circulatory Failure

Purpose

Heparin-binding protein (HBP) is released by granulocytes and has been shown to increase vascular permeability in experimental investigations. Increased vascular permeability in the lungs can lead to fluid accumulation in alveoli and respiratory failure. A generalized increase in vascular permeability leads to loss of circulating blood volume and circulatory failure. We hypothesized that plasma concentrations of HBP on admission to the intensive care unit (ICU) would be associated with decreased oxygenation or circulatory failure.

Methods

This is a prospective, observational study in a mixed 8-bed ICU. We investigated concentrations of HBP in plasma at admission to the ICU from 278 patients. Simplified acute physiology score (SAPS) 3 was recorded on admission. Sequential organ failure assessment (SOFA) scores were recorded daily for three days.

Results

Median SAPS 3 was 58.8 (48–70) and 30-day mortality 64/278 (23%). There was an association between high plasma concentrations of HBP on admission with decreased oxygenation (p<0.001) as well as with circulatory failure (p<0.001), after 48–72 hours in the ICU. There was an association between concentrations of HBP on admission and 30-day mortality (p = 0.002). ROC curves showed areas under the curve of 0,62 for decreased oxygenation, 0,65 for circulatory failure and 0,64 for mortality.

Conclusions

A high concentration of HBP in plasma on admission to the ICU is associated with respiratory and circulatory failure later during the ICU care period. It is also associated with increased 30-day mortality. Despite being an interesting biomarker for the composite ICU population it´s predictive value at the individual patient level is low.

Shock, acute disseminated intravascular coagulation, and microvascular thrombosis: is 'shock liver' the unrecognized provocateur of ischemic limb necrosis?

For unknown reasons, a small minority of critically ill patients with septic or cardiogenic shock, multiorgan failure, and disseminated intravascular coagulation develop symmetrical acral (distal extremity) limb loss due to microvascular thrombosis ('limb gangrene with pulses'). Case reports have described preceding 'shock liver' in some critically ill patients who developed such a picture of ischemic limb necrosis. This suggests that profoundly disturbed procoagulant-anticoagulant balance featuring uncontrolled generation of thrombin-resulting from failure of the protein C and antithrombin natural anticoagulant systems due to insufficient hepatic synthesis of these crucial proteins-could explain the microvascular thrombosis and associated limb loss. We hypothesize that shock liver is the key predisposing risk factor underlying ischemic limb necrosis in the majority of patients who develop this complication in the setting of acute disseminated intravascular coagulation complicating septic or cardiogenic shock. As shock liver precedes onset of limb ischemia by several days, therapeutic intervention may be possible.

[Lactate levels with regards to the pulse pressure in patients with shock]

BACKGROUND

Lactate is one of the most useful biomarkers to screen patients with shock; therefore, the aim of this study was to establish the levels of lactate regarding the pulse pressure in that sort of patients.

METHODS

Observational, retrospective, cross-sectional and descriptive study of patients over 18 years diagnosed with shock from an emergency room of a tertiary care hospital. Lactate levels and pulse pressure were used as biomarkers. We used descriptive statistics, Student's t test and Pearson correlation coefficient.

RESULTS

We obtained 46 patients. The average age was 39.52 (SD 15.22), media initial lactate level was 5.88 mmol/L (SD 3.89) and media final lactate level 3.31 mmol/L (SD = 3.12); initial pulse pressure was 19.78 mmHg (SD 7.45) and final pulse pressure 31.52 mmHg (SD 31.52). The relation of secondary diagnosis did show predominance in chest trauma with 13 patients. There was a statistical significance in initial lactate and final lactate of r = 0.83 (p = 0.00), and initial pulse pressure and final pulse pressure: r = 0.57 (p = 0.001). There was not a significant correlation between final lactate and final pulse pressure (r: -0.184, p = 0.222).

CONCLUSION

Even when several studies emphasize the clinical significance of biomarkers in the diagnosis and management of patients with hypovolemic shock, it is necessary to do more studies in order to find the efficacy of the non-invasive screening in this type of pathology.

H2S during circulatory shock: some unresolved questions

Numerous papers have been published on the role of H2S during circulatory shock. Consequently, knowledge about vascular sulfide concentrations may assume major importance, in particular in the context of "acute on chronic disease", i.e., during circulatory shock in animals with pre-existing chronic disease. This review addresses the questions (i) of the "real" sulfide levels during circulatory shock, and (ii) to which extent injury and pre-existing co-morbidity may affect the expression of H2S producing enzymes under these conditions. In the literature there is a huge range on sulfide blood levels during circulatory shock, in part as a result of the different analytical methods used, but also due to the variable of the models and species studied. Clearly, some of the very high levels reported should be questioned in the context of the well-known H2S toxicity. As long as "real" sulfide levels during circulatory shock are unknown and/or undetectable "on line" due to the lack of appropriate techniques, it appears to be premature to correlate the measured blood levels of hydrogen sulfide with the severity of shock or the H2S therapy-related biological outcomes. The available data on the tissue expression of the H2S-releasing enzymes during circulatory shock suggest that a "constitutive" CSE expression may play a crucial role of for the maintenance of organ function, at least in the kidney. The data also indicate that increased CBS and CSE expression, in particular in the lung and the liver, represents an adaptive response to stress states.

Accuracy of point-of-care blood glucose measurements in critically ill patients in shock

A widely used method in monitoring glycemic status of ICU patients is point-of-care (POC) monitoring devices. A possible limitation to this method is altered peripheral blood flow in patients in shock, which may result in over/underestimations of their true glycemic status. This study aims to determine the accuracy of blood glucose measurements with a POC meter compared to laboratory methods in critically ill patients in shock. POC blood glucose was measured with a glucose-1-dehydrogenase-based reflectometric meter. The reference method was venous plasma glucose measured by a clinical chemistry analyzer (glucose oxidase-based). Outcomes assessed were concordance to ISO 15197:2003 minimum accuracy criteria for glucose meters, bias in glucose measurements obtained by the 2 methods using Bland-Altman analysis, and clinical accuracy through modified error grid analysis. A total of 186 paired glucose measurements were obtained. ISO 2003 accuracy criteria were met in 95.7% and 79.8% of POC glucose values in the normotensive and hypotensive group, respectively. Mean bias for the normotensive group was -12.4 mg/dL, while mean bias in the hypotensive group was -34.9 mg/dL. POC glucose measurements within the target zone for clinical accuracy were 90.2% and 79.8% for the normotensive and hypotensive group, respectively. POC blood glucose measurements were significantly less accurate in the hypotensive subgroup of ICU patients compared to the normotensive group. We recommend a lower threshold in confirming POC blood glucose with a central laboratory method if clinically incompatible. In light of recently updated accuracy standards, we also recommend alternative methods of glucose monitoring for the ICU population as a whole regardless of blood pressure status.

[Clinical significance of continuous thrombocytopenia in predicting sepsis after severe burn]

OBJECTIVE

To explore the relationship between continuous thrombocytopenia and sepsis in patients with severe burns.

METHODS

Clinical data of 148 severely burned patients admitted to our,two burn centers from January 2007 to December 2011 and conforming to the study criteria were retrospectively analyzed. All patients were divided into sepsis group (n =44) and non-sepsis group (n = 104) according to the presence or absence of sepsis within post burn day (PBD) 30. The data of age, gender, total burn area, full-thickness burn area, fluid infusion volume within post burn hour (PBH) 24, plasma concentration of calcium ion on PBD 1, plasma concentration of albumin on PBD 1, platelet count on PBD 1, acute physiology and chronic health evaluation (APACHE) II score on admission, the presence or absence of hypovolemic shock or inhalation injury on admission, the presence or absence of disseminated intravascular coagulation (DIC) within PBH 48, operation or no operation within PBD 3, thrombocytopenia duration within PBD 10, and mortality were statistically compared between two groups to screen the independent risk factors of sepsis. Data were processed with t test, chi-square test, single factor Logistic regression analysis, and multi-factor Logistic regression analysis.

RESULTS

Between two groups, there were statistically significant differences in total burn area, full-thickness burn area, plasma concentration of calcium ion on PBD 1, plasma concentration of albumin on PBD 1, APACHE II score on admission, presence or absence of hypovolem- ic shock on admission, presence or absence of inhalation injury on admission, presence or absence of DIC within PBH 48, and mortality (with t values from 2.433 to 4.082, χ2 values from 8. 818 to 31.528, P < 0.05 or P < 0.01). Furthermore, the duration of thrombocytopenia within PBD 10 in sepsis group was (5.2 ± 2.4) d, which was significantly longer than that in non-sepsis group [(2.9 ± 1.9) d, t =6. 189, P <0.01]. There were no statistically significant differences in the other indexes between two groups (with t values from 0.971 to 1. 250, χ2 values respectively 0. 054 and 1.529, P values above 0.05). Single factor and multi-factor Logistic regression analysis indicated that APACHE II score on admission and duration of thrombocytopenia within PBD 10 were closely related to occurrence of sepsis (with odds ratio respectively 1. 140 and 1.569, P values below 0.01).

CONCLUSIONS

Duration of thrombocytopenia within PBD 10 is one of the risk factors for sepsis in severely burned patients, which can reflect pathophysiological changes in the body, thus providing predictive value for the occurrence of sepsis.

A simple 5-point scoring system, NaURSE (Na+, urea, respiratory rate and shock index in the elderly), predicts in-hospital mortality in oldest old

BACKGROUND

the mortality is high in acutely ill oldest old patients. Understanding the prognostic factors which influence mortality will help clinicians make appropriate management decisions.

METHODS

we analysed prospective mortality audit data (November 2008 to January 2009) to identify variables associated with in-patient mortality in oldest old. We selected those with P < 0.10 from univariate analysis and determined at which cut-point they served as the strongest predictor of mortality. Using these cut-off points, we constructed multivariate logistic regression models. A 5-point score was derived from cut-off points which were significantly associated with mortality tested in a smaller independent re-audit sample conducted in October 2011.

RESULTS

a total of 405 patients (mean 93.5 ± 2.7 years) were included in the study. The mean length of stay was 18.5 ± 42.4 days and 13.8% died as in-patients. Variables (cut-off values) found to be significantly associated with in-patient mortality were admission sodium (>145 mmol/l), urea (≥14 mmol/l), respiratory rate (>20/min) and shock index (>1.0): creating a 5-point score (NaURSE: NaURS in the Elderly). The crude mortality rates were 9.5, 19.9, 34.4, 66.7, and 100% for scores 0, 1, 2, 3 and 4, respectively. Using the cut-off point of ≥2, the NaURSE score has a specificity of 87% (83.1-90.3) and sensitivity of 39% (28.5-50.0), with an AUC value of 0.69 (0.63-0.76). An external independent validation study (n = 121) showed similar results.

CONCLUSIONS

the NaURSE score may be particularly useful in identifying oldest old who are likely to die in that admission to guide appropriate care.

[Effects of fluid resuscitation programs on the levels of inflammatory mediators during burn shock stage]

OBJECTIVE

To explore the effects of different methods of fluid resuscitation on the levels of inflammatory mediators during burn shock stage.

METHODS

Twenty-four miniature swine were numbered from 1 to 24 and randomly divided by EXCEL 2007 into 4 groups of succinylated gelatin, hydroxyethyl starch, Parkland and allogeneic plasma (n = 6 each). Severe burn shock model was established. Succinylated gelatin, hydroxyethyl starch (130/0.4), Ringer's lactate and swine allogenic plasma were used as resuscitation fluid (alternative colloid) according to the burn shock recovery principles (beginning at 2 h post-injury). The parameters of heart rate (HR), blood pressure (BP), urine volume and central venous pressure (CVP) before and within 48 h post-burn were recorded. And the levels of tumor necrosis factor alpha (TNF-α), interleukin (IL) -1β and IL-8 were measured at the time of pre-injury as well as 4 h, 8 h, 24 h and 48 h post-injury. Statistical analyses were performed.

RESULTS

All swine survived the shock stage. TNF-α in succinylated gelatin group was significantly higher at 48 h post-injury than that in allogeneic plasma group ((351 ± 74) vs (215 ± 44) ng/L, P < 0.05). TNF-α in hydroxyethyl starch group was significantly higher at 8 h post-injury than that in allogeneic plasma group ((327 ± 38) vs (249 ± 29) ng/L, P < 0.05). And they were both higher than the pre-burn levels (both P < 0.05). Compared with pre-injury ((508 ± 64) ng/L), the level of IL-1β in succinylated gelatin group increased substantially at 4 h ((563 ± 76) ng/L), 8 h ((589 ± 76) ng/L) and 48 h ((736 ± 42) ng/L) post-injury (all P < 0.05). The hydroxyethyl starch group was higher at 48 h post-injury than that at pre-injury ((574 ± 72) vs (492 ± 41) ng/L, P < 0.05). Also in Parkland group, the levels were higher at 24 h and 48 h hours post-injury than that at pre-injury ((575 ± 31), (584 ± 65) vs (498 ± 33) ng/L, both P < 0.05). Only succinylated gelatin group was significantly higher (P < 0.01) at 48 h post-injury than allogeneic plasma group ((561 ± 48) ng/L). Compared with pre-injury ((561 ± 48) ng/L), the level of IL-8 in succinylated gelatin group increased significantly at 8 h ((1012 ± 100) ng/L), 24 h post-burn ((993 ± 87) ng/L), significantly higher than allogeneic plasma group ((866 ± 99) ng/L) at 24 h (all P < 0.05). Although hydroxyethyl starch and Parkland groups increased significantly at 4 h post-injury and 8 h, 48 h post-injury versus those at pre-injury (all P < 0.05). There was no significant difference at each time point compared with pre-burn (P > 0.05).

CONCLUSIONS

The recovery regimens of hydroxyethyl starch and Parkland groups may restrain the levels of inflammatory mediators. And the effects are similar to those of allogeneic plasma group.

Interpretation of hemolysis tests following administration of a second-generation hemoglobin-based oxygen carrier

Hemoglobin released into the circulation during hemolysis or therapy with chemically modified hemoglobins, exert oxidative and NO-scavenging toxic effects. Pyridoxalated hemoglobin polyoxyethylene conjugate (PHP) is one of the second-generation hemoglobin-based oxygen carriers (HBOCs). We wanted to investigate the metabolism of PHP with a special focus on its consequences for interpreting hemolysis-related diagnostic parameters in PHP-treated patients. Clinical samples were analyzed from 3 patients, who received PHP (as part of the PHOENIX phase III trial) for treatment of catecholamine-resistant distributive shock. In contrast to expectations, clearance of PHP by hemopexin, instead of haptoglobin was documented by increased hemolysis indices, absence of decreased haptoglobin values, presence of free PHP-hemoglobin and exhausted hemopexin concentrations. The present case report is important for both clinicians and laboratorians since it nicely illustrates that a hemolytic aspect of plasma is not necessarely synonymous with hemolysis. A hemolytic aspect of plasma or serum (high hemolysis index) in combination with normal or increased haptoglobin values should draw the attention; additional determination of lactate dehydrogenase and hemopexin may then be useful to distinguish the condition from in vitro hemolysis and to monitor the in vivo elimination of the heme compounds.

[Clinical study on hematocrit used as a predictor for evaluation of resuscitation effect in the early shock stage after burn]

OBJECTIVE

To explore the clinical significance of hematocrit used as a predictor for diagnosis and evaluation of resuscitation effect in the early shock stage after burn.

METHODS

Clinical data of 131 severely burned patients admitted to our burn unit from January 2000 to December 2011 were retrospectively analyzed. The burn patients were divided into group A (n = 80) and group B (n = 51) based on the hematocrit level at post burn hour (PBH) 24. The hematocrit levels in group A were less than or equal to 0.50, which in group B were higher than 0.50. There were no statistically significant differences between two groups in age, gender, body weight, admission time after burn, total burn area, full-thickness burn area, and degree of inhalation injury (P values all above 0.05). Hematocrit levels in the shock stage were recorded. Total urine output, base excess, and the volume of fluid infused per kg per %TBSA at PBH 24 were recorded. Rates of complication and mortality were recorded. Data were processed with t test, chi-square test, and Wilcoxon rank sum test.

RESULTS

Hematocrit level of group A at PBH 24 was decreased to about 0.45, while that of group B was decreased to about 0.55. The urine output in group A at PBH 24 [(61 ± 22) mL/h] was higher than that in group B [(53 ± 20) mL/h, t = 2.212, P < 0.05]. Base excess in group A at PBH 24 [(-6.1 ± 2.9) mmol/L] was significantly higher than that in group B [(-9.0 ± 3.8) mmol/L, t = 4.888, P < 0.01]. The volume infused per kg per %TBSA was higher in group A [(1.9 ± 0.4) mL·kg(-1)·%TBSA(-1)] than in group B [(1.7 ± 0.4) mL·kg(-1)·%TBSA(-1), t = 2.472, P < 0.05]. The rates of complication and mortality in group A [11.3%(9/80), 8.8%(7/80), respectively] were significantly lower than those in group B [27.5%(14/51), 21.6%(11/51), with χ(2) values respectively 5.648 and 4.318, P values all below 0.05].

CONCLUSIONS

Hematocrit can indirectly reflect resuscitation effect in the burn shock stage. Whether hematocrit level can be lowered to 0.45-0.50 during the first 24 hours after burn may be an important index for evaluation of fluid resuscitation effect in the early shock stage after severe burn.

Clinico-pathological particularities of the shock-related pancreatitis

Acute pancreatitis can develop in patients with shock due to the underlying diseases, surgical interventions or because of severe hypoperfusion. The aim of our work was to study the histological alterations of the pancreas in patients dying after cardiogenic, hypovolemic or septic shock, to demonstrate the presence and severity of pancreatic injury. We performed a retrospective study which included patients who died and who were autopsied after different types of shock, hospitalized between 2007-2009 in general and cardiac intensive care units. We excluded the patients with known pancreatic diseases. From 223 patients included in our study 39 presented necrotising hemorrhagic alteration of the pancreatic tissue. There were no differences in histological and immunohistochemical findings between the different etiopathogenetic types of shock. None of the patients had characteristic clinical signs for acute pancreatitis. The digestive symptoms, they presented, could be related to the underlying disease or to postoperative state. The common findings in these patients were prolonged and severe hypotension, associated renal dysfunction, leucocytosis, hyperglycemia and hypocalcemia. Pancreatitis can occur in patients with shock, due to prolonged hypoperfusion of the pancreas. It is difficult to diagnose it because clinical signs are altered due to severity of underlying disease or analgo-sedation commonly used in intensive care. We therefore recommend in patients with shock to consider the possible development of ischemic pancreatitis for prompt and efficient treatment.

Erythrocyte damage of crucian carp (Carassius auratus) caused by microcystin-LR: in vitro study

Fish suffer from anemia and hypovolemic hypotensive shock after in vivo exposure with microcystins.However, except for in vivo causes for anemia and hypotension, an in vitro study of fish erythrocytes exposed to MC is necessary. For a better understanding of hematology toxicity of MC, the main aim of the present study was to investigate the toxic effects of microcystin on fish erythrocytes in vitro. Crucian carp erythrocytes were incubated in vitro with microcystin-LR (MC-LR) at doses of 0, 1, 10, 100 and 1,000 nM.The level of lipid peroxidate significantly increased in MC-LR treatment groups. Glutathione decreased after exposure to MC-LR. The activities of antioxidative enzymes, including superoxide dismutase, catalase,glutathione peroxidase and glutathione-S-transferase,were significantly increased after exposure with MC-LR.The hemolysis was significantly increased, while the activities of acetylcholinesterase, Na?–K?-ATPase and Ca2?–Mg2?-ATPase were significantly decreased. In addition, pathological alterations in agglomerated and jagged erythrocytes were observed in blood smears. The findings indicate that damages to erythrocytes should also be responsible for anemia and hypotensive shock or even death.

High sCD40L levels early after trauma are associated with enhanced shock, sympathoadrenal activation, tissue and endothelial damage, coagulopathy and mortality

BACKGROUND

Severe injury activates the sympathoadrenal, hemostatic and inflammatory systems, but a maladapted response may contribute to a poor outcome. Soluble CD40L is a platelet-derived mediator that links inflammation, hemostasis and vascular dysfunction.

OBJECTIVES

To investigate the association between the sCD40L level and tissue injury, shock, coagulopathy and mortality in trauma patients.

METHODS

A prospective, observational study of 80 trauma patients admitted to a Level I Trauma Center. Data on demography, biochemistry, Injury Severity Score (ISS) and 30-day mortality were recorded and admission plasma/serum analyzed for sCD40L and biomarkers reflecting sympathoadrenal activation (adrenaline, noradrenaline), tissue/endothelial cell/glycocalyx damage (histone-complexed DNA fragments [hcDNA], Annexin V, thrombomodulin and syndecan-1), coagulation activation/inhibition (PF1.2, TAT-complex, antithrombin, protein C, activated protein C, sEPCR, TFPI, von Willebrand factor [VWF], fibrinogen and factor [F] XIII), fibrinolysis (D-dimer, tissue plasminogen activator [tPA] and plasminogen activator inhibitor-1 [PAI-1]) and inflammation (interleukin-6 [IL-6] and sC5b-9). We compared patients stratified by median sCD40L level and investigated predictive values of sCD40L for mortality.

RESULTS

High circulating sCD40L was associated with enhanced tissue and endothelial damage (ISS, hcDNA, Annexin V, syndecan-1 and sTM), shock (pH, standard base excess), sympathoadrenal activation (adrenaline) and coagulopathy evidenced by reduced thrombin generation (PF1.2), hyperfibrinolysis (D-dimer), increased activated partial thromboplastin time (APTT) and inflammation (IL-6) (all P < 0.05). A higher ISS (P = 0.017), adrenaline (P = 0.049) and platelet count (P = 0.012) and lower pH (P =0.002) were associated with higher sCD40L by multivariate linear regression analysis. High circulating sCD40L (odds ratio [OR] 1.84 [95% CI 1.05-3.23], P = 0.034), high age (P = 0.002) and low Glasgow Coma Score (GCS) pre-hospital (P = 0.002) were independent predictors of increased mortality.

CONCLUSIONS

High early sCD40L levels in trauma patients reflect tissue injury, shock, coagulopathy and sympathoadrenal activation and predict mortality. As sCD40L has pro-inflammatory activity and activates the endothelium, sCD40L may be involved in trauma-induced endothelial damage and coagulopathy.

[Primary study on changes of serum proteomics in rabbit superior mesenteric artery occlusion shock]

OBJECTIVE

To explor the changes of serum proteomics in rabbits superior mesenteric artery occlusion (SMAO) shock as well as its possible effect in SMAO shock.

METHODS

SMAO shock model in rabbits were induced by occlusion of the superior mesenteric artery, serum samples were obtained from rabbits before and after SMAO shock, proteins in samples were separated by two-dimensional electrophoresis(2-DE), spots in the 2-DE map were detected and evaluated by PDQuest software 8.0. The spots with different expression level were subjected to matrix assisted laser desorption/ionization-time of flight-time of flight-mass spectrometry (MALDI-TOF-TOF-MS) for identification, the protein database was searched to further characterized the differential proteins.

RESULTS

19 differential protein spots were screened out in the 2-DE maps, 11 proteins were up-regulated and 8 proteins were down-regulated in SMAO shock rabbits' s serum. 4 of the 19 differential protein spots were selected for MALDI-TOF-TOF-MS study, and 2 of the 4 differential protein spots were identified satisfactoryly as paraoxonase and haptoglobin, which content were increased in rabbits' s serum after SMAO shock.

CONCLUSION

Serum proteomics of rabbit change remarkablely before and after SMAO shock, paraoxonase and haptoglobin may be associated with the compensation after SMAO shock.

[Prognostic value of platelet aggreagation capacity and lymphocyte-platelet adhesion in patients suffering acute poisoning with acetic acid]

The patients experiencing severe acute poisoning with acetic acid were divided into 2 groups with and without exotoxic shock to study platelet aggregation capacity and lymphocyte-platelet adhesion. The data obtained were used to develop exotoxic shock probability coefficient for patients with acute poisoning.

[Change in plasma brain natriuretic peptide and its clinical significance in burn patients after delayed fluid resuscitation of shock]

OBJECTIVE

To observe the early change in plasma brain natriuretic peptide (BNP) level in burn patients with long delayed fluid resuscitation of burn shock and its clinical significance.

METHODS

Thirty-six burn patients with second and third degree of burn covering 32%-92% total body surface area were enrolled for the study, among them 10 patients were complicated with serious heart failure (heart failure group), and 26 patients rallied from shock after delayed fluid resuscitation without heart failure (stable group). The level of plasma BNP, lactate dehydrogenase (LDH), MB isoenzyme of creatine kinase (CK-MB), and left ventricle ejection fraction (LVEF) were determined at admission and 3 hours after hospitalization, and 24, 48, 72, 168 hours after the injury in both groups with electrochemiluminescence (ECL).

RESULTS

Compared with stable group, the plasma BNP level (ng/L) of heart failure group at 3 hours after hospitalization, and 24, 48, 72 hours after the burn injury increased significantly (3 hours after hospitalization: 1 521.38+/-121.11 vs. 391.36+/-63.27, 24 hours after burn: 2 516.86+/-193.25 vs. 360.79+/-146.56, 48 hours after burn: 1 587.76+/-169.23 vs. 398.92+/-77.46, 72 hours after burn: 974.45+/-166.33 vs. 283.43+/-68.15, all P<0.01), the level of LVEF lowered significantly (3 hours after hospitalization : 0.33+/-0.03 vs. 0.58+/-0.09, 24 hours after burn: 0.36+/-0.09 vs. 0.60+/-0.10, 48 hours after burn: 0.35+/-0.08 vs. 0.62+/-0.11, 72 hours after burn: 0.39+/-0.10 vs. 0.64+/-0.10, all P<0.05). The levels of LDH (micromolxs(-1) xL(-1)) in stable group were 2.87+/-0.50 at admission, 3.02+/-0.43 3 hours after hospitalization, 4.02+/-0.87 24 hours after burn, 6.90+/-0.87 48 hours after burn, 3.64+/-0.75 72 hours after burn, 2.67+/-0.45 168 hours after burn while in heart failure group, they were 2.97+/-1.40, 3.84+/-0.37, 4.29+/-0.45, 8.50+/-0.38, 3.84+/-0.62, 2.30+/-0.38, respectively; and CK-MB (U/L) in stable group were 59.12+/-13.75 at admission, 70.39+/-10.72 3 hours after hospitalization, 79.29+/-17.27 24 hours after burn, 67.44+/-12.77 48 hours after burn, 30.28+/-7.13 72 hours after burn, 21.44+/-3.15 168 hours after burn while in heart failure group, they were 65.76+/-16.38, 81.46+/-7.92, 86.43+/-14.19, 72.53+/-11.27, 36.39+/-6.18, 22.85+/-7.26, respectively. No statistically significant difference was found in changes in both LDH and CK-MB between two groups (all P>0.05).

CONCLUSION

Determination of the plasma BNP is a simple and useful method in detecting heart failure during resuscitation of shock after a serious burn injury.

Comparison of lactate, base excess, bicarbonate, and pH as predictors of mortality after severe trauma in rhesus macaques (Macaca mulatta)

Social group housing of rhesus macaques at biomedical facilities is advocated to improve the psychologic wellbeing of these intelligent and social animals. An unintended outcome of social housing in this species is increased intraspecific aggression resulting in cases of severe multiple trauma and posttraumatic shock. The metabolic correlates of oxygen debt are likely important quantifiers of the severity of posttraumatic shock and may serve as useful guides in the treatment of these cases. The purpose of this retrospective study was to evaluate venous blood lactate, base excess, bicarbonate, and pH as predictors of mortality. These 4 variables were assessed in 84 monkeys with severe traumatic injury and shock. Data were available from blood samples collected prior to resuscitation therapy and the day after resuscitation therapy. The pre- and postresuscitation therapy levels of the variables then were tested for association with 6-d survival. When measured prior to resuscitation therapy, all variables were strongly correlated with each other and had a statistically significant association with survival. No single variable had both strong specificity and high sensitivity when measured prior to resuscitation therapy. Survival analysis showed that as the number of categorical indicators of acidosis increased, 6-d survival decreased. Analysis of the 4 variables after resuscitation therapy indicated that lactate was the only variable significantly associated with survival in our study.

Comparing two different arginine vasopressin doses in advanced vasodilatory shock: a randomized, controlled, open-label trial

PURPOSE

To compare the effects of two arginine vasopressin (AVP) dose regimens on the hemodynamic response, catecholamine requirements, AVP plasma concentrations, organ function and adverse events in advanced vasodilatory shock.

METHODS

In this prospective, controlled, open-label trial, patients with vasodilatory shock due to sepsis, systemic inflammatory response syndrome or after cardiac surgery requiring norepinephrine >0.6 microg/kg/min were randomized to receive a supplementary AVP infusion either at 0.033 IU/min (n = 25) or 0.067 IU/min (n = 25). The hemodynamic response, catecholamine doses, laboratory and organ function variables as well as adverse events (decrease in cardiac index or platelet count, increase in liver enzymes or bilirubin) were recorded before, 1, 12, 24 and 48 h after randomization. A linear mixed effects model was used for statistical analysis in order to account for drop-outs during the observation period.

RESULTS

Heart rate and norepinephrine requirements decreased while MAP increased in both groups. Patients receiving AVP at 0.067 IU/min required less norepinephrine (P = 0.006) than those infused with AVP at 0.033 IU/min. Arterial lactate and base deficit decreased while arterial pH increased in both groups. During the observation period, AVP plasma levels increased in both groups (both P < 0.001), but were higher in the 0.067 IU/min group (P < 0.001) and in patients on concomitant hydrocortisone. The rate of adverse events and intensive care unit mortality was comparable between groups (0.033 IU/min, 52%; 0.067 IU/min, 52%; P = 1).

CONCLUSIONS

A supplementary AVP infusion of 0.067 IU/min restores cardiovascular function in patients with advanced vasodilatory shock more effectively than AVP at 0.033 IU/min.

[Changes in B-type natriuretic peptide in plasma and its clinical significance in patients with severe burn during shock stage]

OBJECTIVE

To study the plasma content of B-type natriuretic peptide (BNP) in patients with severe burn during shock stage and probe its clinical significance.

METHODS

Forty-two patients aged 18-60 years, with total burn surface area 30% TBSA or full-thickness burn area > or = 10% TBSA, hospitalized within 4 hours after burn, were divided into A group (with total burn surface area 30%-50% TBSA or full-thickness burn area 10%-20% TBSA, n = 21), and B group (with total burn surface area > 50% TBSA or full-thickness burn area > 20% TBSA, n = 21). Twenty patients admitted during the same time for plastic surgery were enrolled as control group. The plasma levels of BNP, creatine kinase (CK), CK-MB, troponin I (TnI) of all patients were determined on admission. The levels of BNP, TnI and fluid resuscitation volume were examined at 8, 16, 24, 48 post burn hour (PBH) in A and B groups. Analysis of correlation between BNP and fluid resuscitation volume was performed.

RESULTS

On admission: BNP level in A group (68 +/- 19 ng/L) and B group (99 +/- 38 ng/L), respectively, was increased as compared with that in control group (17 +/- 7 ng/L, P < 0.01). TnI level in A group (2.13 +/- 0.67 microg/L) and B group (2.98 +/- 0.58 microg/L), respectively, was increased as compared with that in control group (0.12 +/- 0.03 microg/L, P < 0.01). There was no obvious difference in CK, CK-MB levels among A, B, and control groups (P > 0.05). BNP levels in A, B groups continuously rose during 8-48 PBH, and they were positively correlated with fluid resuscitation volume. TnI level peaked at 24 PBH, and decreased at 48 PBH.

CONCLUSIONS

The plasma level of BNP is sensitive to reflect changes in myocardial ischemia and hypoxia as a rise in level of TnI in shock stage of severe burn, and it was positively correlated with fluid resuscitation volume. BNP can be used to guide fluid resuscitation during shock stage.

[Improved detection of the pulse oximeter signal with a digital nerve block in patients in poor health status]

OBJECTIVE

To demonstrate the efficacy of a digital nerve block for improving pulse oximetry in conditions of low tissue perfusion.

METHOD

A randomized single-blind study of adult patients undergoing surgery under general anesthesia for conditions characterized by hypoperfusion. Patients were assigned to a control group or an experimental group. The experimental group received a digital nerve block in the middle finger of the left hand; a sensor was then placed on the finger for between 120 and 300 minutes. Age, sex, diagnosis, total observation time (TOT), percentage of time with no pulse oximeter signal (NoPO), and percentage of time with an unstable pulse oximeter signal (UnstPO) were recorded. Each patient was questioned between 16 and 24 hours after surgery and was examined for flushing, paresthesia, hypoesthesia, pain, and ecchymosis. The chi2 test was used to compare dichotomized or nominal variables and the t test was used to compare age, TOT, NoPO, and UnstPO. Values of P<.05 were considered statistically significant in both cases.

RESULTS

Fifty patients were randomized to each group. A total of 82 patients remained in the study (control group=42, experimental group=40). There were no significant between-group differences in diagnoses or TOT. The mean values for NoPO and UnstPO were higher in the control group than in the experimental group (11.1% vs 4.4% and 35.9% vs 15.7%, respectively; P<.001).

CONCLUSION

A digital nerve block can be used to prevent pulse oximetry failures in conditions of low peripheral perfusion.

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

INTRODUCTION

Critically ill patients might present complex acid-base disorders, even when the pH, PCO2, [HCO3-], 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 > or = 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, [HCO3-], 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 [HCO3-] (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, [HCO3-], and [BE] as a result of associated hypochloremic alkalosis.

THE IMPACT OF ARTERIAL OXYGEN TENSION ON VENOUS OXYGEN SATURATION IN CIRCULATORY FAILURE

Central and mixed venous oxygen saturations have been used to guide resuscitation in circulatory failure, but the impact of arterial oxygen tension on venous oxygen saturation has not been thoroughly evaluated. This observational study investigated the impact of arterial oxygen tension on venous oxygen saturation in circulatory failure. Twenty critically ill patients with circulatory failure requiring mechanical ventilation and a pulmonary artery catheter in an intensive care unit in a tertiary hospital in Western Australia were recruited. Samples of arterial blood, central venous blood, and mixed venous blood were simultaneously and slowly drawn from the arterial, central venous, and pulmonary artery catheter, respectively, at baseline and after the patient was ventilated with 100% inspired oxygen for 5 min. The blood samples were redrawn after a significant change in cardiac index (>or =10%) from the baseline, occurring within 24 h of study enrollment while the patient was ventilated with the same baseline inspired oxygen concentration, was detected. An increase in inspired oxygen concentration significantly increased the arterial oxygen tension from 12.5 to 38.4 kPa (93.8-288 mmHg) (mean difference, 25.9 kPa; 95% confidence interval [CI], 7.5-31.9 kPa; P < 0.001) and the venous oxygen saturation from 69.9% to 76.5% (mean difference, 6.6%; 95% CI, 5.3% - 7.9%; P < 0.001). The effect of arterial oxygen tension on venous oxygen saturation was more significant than the effect associated with changes in cardiac index (mean difference, 2.8%; 95% CI, -0.2% to 5.8%; P = 0.063). In conclusion, arterial oxygen tension has a significant effect on venous oxygen saturation, and this effect is more significant and consistent than the effect associated with changes in cardiac index.

Fibrinolysis in patients with an abdominal aortic aneurysm with special emphasis on rupture and shock

BACKGROUND

A ruptured abdominal aortic aneurysm (AAA) is associated with high mortality. Postoperative complications such as hemorrhage, multiple organ failure, myocardial infarction, and thromboembolism are common. An active and balanced hemostatic system is essential to avoid bleeding as well as thrombosis. When these activities are not properly regulated the patient is at risk of developing either excessive bleeding or thrombosis-related complications. Previous studies have shown a state of activated coagulation in patients with ruptured AAA. However, there are conflicting results regarding the fibrinolytic response.

OBJECTIVES

The aim of the present study was to investigate the fibrinolytic state pre-operatively in patients with ruptured and non-ruptured AAA in relation to the clinical outcome with special regard to the influence of shock.

METHODS

A prospective study was performed on 95 patients who underwent surgery for a ruptured AAA with shock (n = 43), a ruptured AAA without shock (n = 12), and a non-ruptured AAA (n = 40). Forty-one controls without an aneurysm were matched to the AAA patients according to age, gender and smoking habits. Plasma levels of tissue plasminogen activator antigen (tPAag), and plasminogen activator inhibitor type-1 (PAI-1) were measured as markers of fibrinolytic activity. D-dimer, a marker of fibrin turnover, was also measured.

RESULTS

D-dimer was significantly higher in patients with a non-ruptured AAA compared with controls without AAA. There were significantly higher levels of D-dimer, tPAag, and PAI-1 in patients operated for ruptured compared with non-ruptured AAA. tPAag was also significantly higher in ruptured AAA patients with shock compared with without shock. No deaths occurred in patients operated on for a non-ruptured AAA or ruptured AAA without shock. There were 12 deaths after repair of a ruptured AAA with shock, of which two patients died from bleeding and the remaining 10 from multiple organ failure and cardiac failure.

CONCLUSION

Our results indicate a state of activated coagulation in patients with a non-ruptured AAA, the state being intensified by rupture. The present data show normal fibrinolytic activities in patients with a non-ruptured AAA, but increased systemic fibrinolysis, as demonstrated by elevated tPAag level, in patients with a ruptured AAA. The elevated PAI-1 level indicates a simultaneous inhibition of the systemic fibrinolysis. Furthermore, the hyperfibrinolytic state was reinforced by shock in this study. However, the clinical outcome, with a relatively high incidence of thrombosis-related deaths, indicate a prothrombotic state instead of a hyperfibrinolytic state as a major point of attention in patients with shock as a result of a ruptured AAA.

NOREPINEPHRINE AND INTESTINAL MUCOSAL PERFUSION IN VASODILATORY SHOCK AFTER CARDIAC SURGERY

Patients with norepinephrine-dependent vasodilatory shock after cardiac surgery (n = 10) were compared with uncomplicated postcardiac surgery patients (n = 10) with respect to jejunal mucosal perfusion, gastric-arterial PCO2 gradient, and splanchnic oxygen demand/supply relationship. Furthermore, the effects of norepinephrine-induced variations in MAP on these variables were evaluated in vasodilatory shock. Norepinephrine infusion rate was randomly and sequentially titrated to target MAPs of 60, 75, and 90 mmHg (0.25 +/- 0.24, 0.37 +/- 0.21, and 0.55 +/- 0.39 microg/kg per minute, respectively). Data on jejunal mucosal perfusion, jejunal mucosal hematocrit, and red blood cell (RBC) velocity (laser Doppler flowmetry) as well as gastric-arterial PCO2 gradient (gastric tonometry) and splanchnic oxygen and lactate extraction (hepatic vein catheter) were obtained. Splanchnic oxygen extraction was 71 +/- 16% in the vasodilatory shock group and 41 +/- 9% in the control group (P < 0.001), whereas splanchnic lactate extraction did not differ between the two groups. Jejunal mucosal perfusion (61%; P < 0.001), RBC velocity (35%; P < 0.01), and gastric-arterial mucosal PCO2 gradient (150%; P < 0.001) were higher in the vasodilatory shock group compared with those of the control group. Jejunal mucosal perfusion, jejunal mucosal hematocrit, RBC velocity, gastric-arterial mucosal PCO2 gradient, splanchnic oxygen extraction, and splanchnic lactate extraction were not affected by increasing infusion rates of norepinephrine. In patients with norepinephrine-dependent vasodilatory shock after cardiac surgery, intestinal mucosal perfusion was higher, whereas splanchnic and gastric oxygen demand/supply relationships were impaired compared with postoperative controls, suggesting that intestinal mucosal perfusion is prioritized in vasodilatory shock. Increasing MAP from 60 to 90 mmHg with norepinephrine in clinical vasodilatory shock does not affect intestinal mucosal perfusion and gastric or global splanchnic oxygen demand/supply relationships.

Hormonally active women tolerate shock-trauma better than do men: a prospective study of over 4000 trauma patients

OBJECTIVE

To test the hypothesis that comparably injured women, especially those in the hormonally active age groups, would manifest a better preserved hemodynamic response and tissue perfusion after major trauma than do men.

SUMMARY BACKGROUND DATA

The notion that premenopausal women are more resistant than men to shock and trauma has been shown in numerous preclinical models. However, human studies on the effects of gender on outcome after shock-trauma are less clear, and none has examined the effect of gender on the immediate postinjury response to major trauma.

METHODS

Prospective series of all patients at a Level I trauma center from January 2000 to December 2005. Study patients were all patients arriving to the trauma area of the emergency department and having a serum lactate drawn within 30 minutes of arrival. Demographic data, injury severity indices, blood utilization, and lactate levels were recorded. Lactate was used as a marker of the hemodynamic response to injury, because it has been shown to be an excellent and accurate indicator of inadequate tissue perfusion.

RESULTS

: A total of 5192 patients were eligible for the study of which 4106 fulfilled the study requirements and were enrolled. Initial serum lactate levels were significantly lower in premenopausal (age 14-44) and perimenopausal (age 45-54) women than in men of the same age groups (P < 0.001), even though the Injury Severity Score of the women was significantly higher than that of the men (24 vs. 18; P < 0.1). When patients were stratified into major injury groups as well as groups receiving blood transfusions, the premenopausal women were also found to have lower initial serum lactate levels and receive less blood, while having a greater magnitude of injury as reflected in their Injury Severity Score.

CONCLUSION

The data firmly establishes a proof of principle that hormonally active human women have a better physiologic response to similar degrees of shock and trauma than do their male counterparts. These gender-based differences should be taken into account in designing studies evaluating the response to shock-trauma.

The guanylyl cyclase inhibition by MB as vasoplegic circulatory shock therapeutical target

There were strong evidences that NO has capital importance in the progressive vasodilatation that associates to the varied circulatory shock forms. The decreased systemic vascular resistance observed in irreversible hemorrhagic (hypovolemic) and septic shock may be due to the excess production of nitric oxide. Other forms of shock associated to anaphylaxis (anaphylactic shock, SIRS) and ischemia reperfusion injury (cardiogenic shock, organ transplants), may involve nitric oxide overproduction. In these situations, the nitric oxide-induced loss of vascular sensitivity to catecholamines and myocardial depression contributes to lethal hypotension. As NO vasodilatation is cyclic GMP-mediated, there were two therapeutical options: a) The unspecific NO synthesis inhibition by L-arginine analogs, iNOS-specific inhibition by corticoids and/or aminoguanidine and; b) Guanylyl cyclase inhibition by MB. As the NO synthesis inhibition is associated to tissue necrosis and adverse hemodynamic effects and its clinical use was associated with high mortality, the second option using MB is safer and more rational. The elaboration of this text was motivated to suggest the guanylyl cyclase inhibition by MB as vasoplegic circulatory shock therapeutical target.

Effects of early enteral arginine supplementation on resuscitation of severe burn patients

OBJECTIVES

To investigate the effects of dietary supplementation of l-arginine (l-Arg) on shock in severely burned patients.

METHODS

This was a prospective, randomized, single blind, controlled study. Forty-seven severely burned patients due to various causes with a total burn surface area (TBSA) more than 50% each admitted in early postburn phase (within 10h postburn) were included in this study. All patients were treated by the traditional resuscitation program of our institute. After the nasogastric feeding tube was placed, they were randomly divided into three groups-(1) group A400 (n = 16): giving gastrointestinal feeding with 500 ml 5% GNS, containing l-Arg (400 mg/ kgday) at equal pace with fluid resuscitation; (2) group A200 (n = 16): giving gastrointestinal feeding with 500 ml 5% GNS containing l-Arg (200 mg/ kgday); (3) group C (n = 15): giving gastrointestinal feeding with 500 ml 5% GNS without any supplementation. The feeding started within 12h after burn and lasted for 72 h, the feeding rate was controlled by an enteral feeding pump. The following parameters were observed on days (PBD) 1-4: serum nitric oxide content (NO), mean arterial blood pressure (MAP), oxygenation index (PO2/FiO2), and arterial blood content of lactic acid (LA). Gastric mucosal blood flow was measured by laser Doppler flow-metry on PBD1 and PBD2.

RESULTS

(1) Enteral feeding of l-Arg did not change MAP of severely burned patients, with no difference in MAP between the l-Arg supplemented and control groups. (2) There were significant changes of the l-Arg supplemented groups (A400 and A200), with an increased gastric mucosa blood flow, oxygenation index, and a decreased LA content in arterial blood, compared with the control group. (3) The serous NO content was significantly decreased in the A400 group on PBD2-4 (P < 0.01), and in the A200 group on PBD4 (P < 0.05) compared with the control group.

CONCLUSIONS

Enteral feeding with l-arginine supplementation on early stage of burn decreases NO production to a relatively normal level and exerts beneficial effects on the resuscitation of burned shock.

Natriuretic peptide testing for the evaluation of critically ill patients with shock in the intensive care unit: a prospective cohort study

Introduction

Amino-terminal pro-brain natriuretic peptide (NT-proBNP) is useful in evaluating heart failure, but its role in evaluating patients with shock in the intensive care unit (ICU) is not clear.

Method

Forty-nine consecutive patients in four different ICUs with shock of various types and with an indication for pulmonary artery catheter placement were evaluated. Analyses for NT-proBNP were performed on blood obtained at the time of catheter placement and results were correlated with pulmonary artery catheter findings. Logistic regression identified independent predictors of mortality.

Results

A wide range of NT-proBNP levels were observed (106 to >35,000 pg/ml). There was no difference in median NT-proBNP levels between patients with a cardiac and those with a noncardiac origin to their shock (3,046 pg/ml versus 2,959 pg/ml; P = 0.80), but an NT-proBNP value below 1,200 pg/ml had a negative predictive value of 92% for cardiogenic shock. NT-proBNP levels did not correlate with filling pressures or hemodynamics (findings not significant). NT-proBNP concentrations were higher in patients who died in the ICU (11,859 versus 2,534 pg/ml; P = 0.03), and the mortality rate of patients in the highest log-quartile of NT-proBNP (66.7%) was significantly higher than those in other log-quartiles (P < 0.001); NT-proBNP independently predicted ICU mortality (odds ratio 14.8, 95% confidence interval 1.8–125.2; P = 0.013), and was superior to Acute Physiology and Chronic Health Evaluation II score and brain natriuretic peptide in this regard.

Conclusion

Elevated levels of NT-proBNP do not necessarily correlate with high filling pressures among patients with ICU shock, but marked elevation in NT-proBNP is strongly associated with ICU death. Low NT-proBNP values in patients with ICU shock identifed those at lower risk for death, and may be useful in excluding the need for pulmonary artery catheter placement in such patients.

New horizons: NT-proBNP for risk stratification of patients with shock in the intensive care unit

B-type natriuretic peptide (BNP) and amino-terminal pro-BNP (NT-proBNP) are promising cardiac biomarkers that have recently been shown to be of diagnostic value in decompensated heart failure, acute coronary syndromes and other conditions resulting in myocardial stretch and volume overload. In view of the high prevalence of cardiac disorders in the intensive care unit, the experience of elevated natriuretic peptide levels in the critically ill might be of enormous diagnostic and therapeutic value. BNP and NT-proBNP levels rise to different degrees in critical illness and may also serve as markers of severity and prognosis in diseases beyond acute or chronic heart failure. The diagnostic and prognostic use of natriuretic peptides in the intensive care setting for patients with various forms of shock could be an attractive alternative as noninvasive markers of cardiac dysfunction that could obviate the need for pulmonary artery catheterization in some patients.

Effects of post-treatment with direct hemoperfusion using a CTR column on mortality and inflammatory responses to endotoxin-induced shock in rats

BACKGROUND

To clarify the effects of post-treatment with direct hemoperfusion using a CTR column on the mortality and inflammatory responses to endotoxin-induced shock in rats.

METHODS

Thirty-six male rats were randomly assigned to 1 of 3 groups (n = 12/group): the endotoxemic group, receiving intravenous Escherichia coli endotoxin (15 mg/kg over 2 min); the control column group, treated without CTR for 120 min at 2 h after endotoxin injection, and CTR-post-treatment group, treated with CTR for 120 min at 2 h after endotoxin injection. Hemodynamics, arterial blood gases, and mortality were recorded for the 8-hour observation period, and plasma cytokine concentrations were measured every 4 h.

RESULTS

The mortality rates were 83, 83 and 33% for the endotoxemic, control column, and CTR post-treatment groups, respectively. The increases in IL-6 concentrations were less for the CTR post-treatment group than the other 2 groups.

CONCLUSION

The present study shows that CTR post-treatment inhibited hypotension and elevations in IL-6 concentrations, reducing the mortality rate of rats with endotoxin-induced shock.

Meaning of arterio-venous PCO2 difference in circulatory shock

The arterovenous difference in carbon dioxide tension (DeltaPCO2) can be calculated after simultaneous sampling of arterial blood (PaCO2) and of mixed venous blood from the distal of a pulmonary artery catheter (PvCO2). Under physiological conditions, DeltaPCO2 ranges from 2 to 5 mmHg. The DeltaPCO2 depends on carbon dioxide and cardiac output by a complex fashion. In this article, we detail the influence of these factors on DeltaPCO2 in normoxic conditions and in hypoxic conditions. We bring evidence that DeltaPCO2 cannot serve as a marker of tissue hypoxia contrary to what was initially thought. However, DeltaPCO2 can be considered as a marker of the adequacy of venous blood flow (i.e. cardiac output) to remove the total CO2 produced by the peripheral tissues. In this regard, the knowledge of DeltaPCO2 should help the clinicians for the decision of giving therapy aimed at increasing cardiac output.

[B-natriuretic peptide and cardiological emergencies in childhood]

The increase in B-natiuretic peptide (BNP) is well correlated with cardiovascular symptoms in adults. Its use in children is recent and only partially evaluated. The authors undertook a prospective study of BNP concentrations and its kinetics in 54 children with an average age of 15 months (5 days to 11 years) admitted as paediatric emergencies. The symptoms were dyspnoea (60%), shock (15%), suspicion of Kawasaki disease (15%) and other (10%). Twenty children had BNP levels of more than 100 pg/ml related to decompensation of known congenital heart disease in 7 patients (average BNP 462 +/- 323 pg/ml), due to neonatal coarctation in 2 patients (BNP > 3000 pg/ml), due to cardiomyopathy in 6 patients (BNP= 2576 +/- 1215 pg/ml), due to an arrhythmia in 1 patient (BNP= 3754 pg/ml) and to Kawasaki disease in 4 patients (BNP= 521 +/- 448 pg/ml). Thirty-four children had BNP values of less than 100 pg/ml; 29 had no cardiac disease and 5 had known congenital heart disease with other symptoms. Measuring BNP is quick and economical and is a valuable aid in the diagnosis of cardiac dysfunction in symptomatic children in the emergency room. High BNP values seem to be correlated with the severity of the cardiac disease. Low BNP values seem to have a good negative predictive value in children without underlying cardiac disease. The interpretation of intermediary values, especially when there is previous cardiac disease, is more difficult in view of the absence of known threshold values for different haemodynamic situations. Further studies are required to determine the value of this test for the follow-up and setting up of prognostic values in children with congenital heart disease.