Catecholamines and vasopressin during critical illness

The prognostic value of the stress hyperglycemia ratio for all-cause and cardiovascular mortality in patients with diabetes or prediabetes: insights from NHANES 2005-2018

BACKGROUND

The Stress hyperglycemia ratio (SHR) is a novel marker reflecting the true acute hyperglycemia status and is associated with clinical adverse events. The relationship between SHR and mortality in patients with diabetes or prediabetes is still unclear. This study aimed to investigate the predictive value of the SHR for all-cause and cardiovascular mortality in patients with diabetes or prediabetes.

METHODS

This study included 11,160 patients diagnosed with diabetes or prediabetes from the National Health and Nutrition Examination Survey (2005-2018). The study endpoints were all-cause and cardiovascular mortality, and morality data were extracted from the National Death Index (NDI) up to December 31, 2019. Patients were divided into SHR quartiles. Cox proportion hazards regression was applied to determine the prognostic value of SHR. Model 1 was not adjusted for any covariates. Model 2 was adjusted for age, sex, and race. Model 3 was adjusted for age, sex, race, BMI, smoking status, alcohol use, hypertension, CHD, CKD, anemia, and TG.

RESULTS

During a mean follow-up of 84.9 months, a total of 1538 all-cause deaths and 410 cardiovascular deaths were recorded. Kaplan-Meier survival analysis showed the lowest all-cause mortality incidence was in quartile 3 (P < 0.001). Multivariate Cox regression analyses indicated that, compared to the 1st quartile, the 4th quartile was associated with higher all-cause mortality (model 1: HR = 0.89, 95% CI 0.74-10.7, P = 0.226; model 2: HR = 1.24, 95% CI 1.03-1.49, P = 0.026; model 3: HR = 1.30, 95% CI 1.08-1.57, P = 0.006). The 3rd quartile was associated with lower cardiovascular mortality than quartile 1 (model 1: HR = 0.47, 95% CI 0.32-0.69, P < 0.001; model 2: HR = 0.66, 95% CI 0.45-0.96, P = 0.032; model 3: HR = 0.68, 95% CI 0.46-0.99, P = 0.049). There was a U-shaped association between SHR and all-cause mortality and an L-shaped association between SHR and cardiovascular mortality, with inflection points of SHR for poor prognosis of 0.87 and 0.93, respectively.

CONCLUSION

SHR is related to all-cause and cardiovascular mortality in patients with diabetes or prediabetes. SHR may have predictive value in those patients.

Association between dose of catecholamines and markers of organ injury early after out-of-hospital cardiac arrest

BACKGROUND

Catecholamines are recommended as first-line drugs to treat hemodynamic instability after out-of-hospital cardiac arrest (OHCA). The benefit-to-risk ratio of catecholamines is dose dependent, however, their effect on metabolism and organ function early after OHCA has not been investigated.

METHODS

The Post-Cardiac Arrest Syndrome (PCAS) pilot study was a prospective, observational, multicenter study. The primary outcomes of this analysis were association between norepinephrine/cumulative catecholamines doses and neuron specific enolase (NSE)/lactate concentration over the first 72 hours after resuscitation. The association was adjusted for proven OHCA mortality predictors and verified with propensity score matching (PSM).

RESULTS

Overall 148 consecutive OHCA patients; aged 18-91 (62.9 ± 15.27), 41 (27.7%) being female, were included. Increasing norepinephrine and cumulative catecholamines doses were significantly associated with higher NSE concentration on admission (r = 0.477, p < 0.001; r = 0.418, p < 0.001) and at 24 hours after OHCA (r = 0.339, p < 0.01; r = 0.441, p < 0.001) as well as with higher lactate concentration on admission (r = 0.404, p < 0.001; r = 0.280, p < 0.01), at 24 hours (r = 0.476, p < 0.00; r = 0.487, p < 0.001) and 48 hours (r = 0.433, p < 0.01; r = 0.318, p = 0.01) after OHCA. The associations remained significant up to 48 hours in non-survivors after PSM.

CONCLUSIONS

Increasing the dose of catecholamines is associated with higher lactate and NSE concentration, which may suggest their importance for tissue oxygen delivery, anaerobic metabolism, and organ function early after OHCA.

Copeptin, pro-atrial natriuretic peptide and pro-adrenomedullin as markers of hypoxic stress in patients with obstructive sleep apnea-a prospective intervention study

Study Objectives

Obstructive sleep apnea (OSA) might lead to oxidative stress, inflammation and elevated circulating copeptin, proANP and proADM levels. We aimed to evaluate whether the levels of these prohormones are higher in patients with OSA and whether they might change under continuous positive airway pressure (CPAP) therapy, serving as potential proxies for the diagnosis and therapy-response in OSA.

Methods

A total of 310 patients with suspicion of OSA were recruited. Screening for OSA was performed using overnight pulse oximetry followed by polygraphy and a venous puncture in the morning. All patients diagnosed with OSA underwent CPAP adaptation. A venous puncture was conducted in the night before CPAP and in the following morning. At 1 and 6 months of treatment, polygraphy was performed, followed by a venous puncture in the morning. In the acquired blood, copeptin, proANP and proADM levels were measured.

Results

We analyzed 232 patients with OSA and 30 patients without OSA. Our results indicated that only copeptin levels differed significantly among patients with and without OSA at baseline. In OSA patients, the levels of proADM significantly changed after 1 and 6 months on CPAP therapy, when compared to baseline (p < 0.001 and p = 0.020). Additionally, proANP levels significantly decreased after 12 h on CPAP therapy, as compared to baseline levels (p < 0.001).

Conclusions

Copeptin is significantly associated with the presence of OSA. ProANP levels might serve as a potential proxy for the acute response to non-invasive ventilation (12 h), while proADM reflects the long-term response (1 and 6 months).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12931-021-01704-0.

The diagnosis and prognostic value of plasma copeptin in traumatic brain injury: a systematic review and meta-analysis

OBJECTIVE

The purpose of this meta-analysis was to assess the diagnosis and prognostic value of plasma copeptin levels after traumatic brain injury (TBI).

METHODS

The databases PubMed, Cochrane Library, OvidSP, Google Scholar, VIP, CNKI, and WFSD were systematically searched from the inception dates to May 9, 2020. The pooled analysis of relevant data was conducted by the RevMan 5.3 software. Subgroups analysis was performed to explore the impact of age, country, male ratio, follow-up time, and Glasgow coma score (GCS) on the pooled area under curve (AUC) values of assessment mortality.

RESULTS

A total of 17 studies involving 2654 participants were included in the current meta-analysis. The pooled results demonstrated that increased plasma copeptin levels were significantly associated with TBI [SMD, 2.44; 95%CI, 1.59 ~ 3.29; P < 0.00001] and also were significantly associated with mortality [SMD, 1.37; 95%CI, 1.16 ~ 1.58; P < 0.00001], and poor functional outcomes (PFO) [SMD, 1.44; 95%CI, 1.20 ~ 1.68; P < 0.00001] in patients with TBI. Furthermore, the copeptin had a significant value in diagnosing brain concussion [AUC, 0.90; 95%CI, 0.84 ~ 0.95; P < 0.00001] and predicting progressive hemorrhagic injury [AUC, 0.83; 95%CI, 0.80 ~ 0.87; P < 0.00001], acute traumatic coagulopathy [AUC, 0.84; 95%CI, 0.79 ~ 0.89; P < 0.00001], mortality [AUC, 0.89; 95%CI, 0.87 ~ 0.92; P < 0.00001], and PFO [AUC, 0.88; 95%CI, 0.84 ~ 0.92; P < 0.00001] in patients with TBI. The subgroup analysis findings suggested that the age, country, male ratio, follow-up time, and GCS were not obvious factors influencing the pooled AUC values of assessment mortality.

CONCLUSIONS

The authors indicate that the plasma copeptin is a potentially promising biomarker for TBI diagnosis and prognosis prediction.

Prognostic value of copeptin in patients with aneurysmal subarachnoid hemorrhage

BACKGROUND

Recently, copeptin has been identified as a plasma prognosis marker in acute ischemic stroke and intracerebral hemorrhage (ICH). This study investigated the prognostic value of copeptin in the patients with aneurysmal subarachnoid hemorrhage(aSAH).

METHODS

In this retrospective study, 243 consecutive patients were included. Upon admission, plasma copeptin levels were measured by enzyme-linked immunosorbent assay. The end points were mortality and poor functional outcome (Glasgow Outcome Scale score of 1-3) after 3 months.

RESULTS

In 243 patients, 112 (46.1%) were male and median age was 58 years (IQR 49-68). Median copeptin plasma levels were 21.0 pmol/l (IQR 13.2-31.2). Copeptin levels increased with increasing severity of aSAH as defined by the World Federation of Neurological Surgeons (WFNS) score. Patients with a poor outcome and nonsurvivors had significantly increased copeptin levels on admission (P < .001 both). In the multivariate analysis, for each 1 pmol/l increase of plasma concentration of copeptin, the adjusted risk of poor outcomes and mortality would be increased by and 6% (1.06 [1.02-1.10], P < .001) and 9% (1.09 [1.03-1.13], P < .001), respectively. Receiver operating characteristics to predict functional outcome and mortality demonstrated areas under the curve of copeptin of 0.74 (95% confidence interval [CI], 0.67-0.81) and 0.81 (95% CI, 0.74-0.87), which was comparable with the WFNS score(P > .05) but superior to C-reactive protein and IL-6 (P < .01).

CONCLUSIONS

The data shows that copeptin levels may reliably predict short-term prognosis at its onset in aSAH patients.

An exploratory pilot study with copeptin as a biomarker for individualizing treatment for nocturnal polyuria

OBJECTIVE

The aim of the present study was to investigate the use of random copeptin concentrations as possible biomarkers for the differential diagnosis of nocturnal polyuria (NP).

METHODS

In all, 111 patients with and without nocturia were enrolled in the study. Patients with a neurogenic bladder and/or those who had undergone bladder or urethral surgery were excluded from the study. All patients completed a 72-hour frequency-volume chart and a renal function profile. A random blood sample was obtained during the day for measurement of plasma copeptin concentrations, osmolality, and serum sodium and creatinine concentrations. The effect of the use of different definitions for NP was evaluated.

RESULTS

The median age of the study participants was 61 years, and 48% were female. Copeptin was significantly correlated with urinary and plasma osmolality, as well as free water clearance (r=0.43, 0.56 and -0.38 respectively; P < .001 for all). Study participants were divided into 3 groups: controls (n = 51), those with NP (n = 41), and those with global polyuria (n = 19). Copeptin concentrations were significantly lower in subjects with global polyuria than in those with NP and the control group (2.96 vs 3.97 and 3.94 pM, respectively; P = .008 and .005). There was no significant difference in random daytime copeptin concentrations between the NP and control groups (P = .972). The results differed when other definitions for NP were used (e.g. NPi33 or NUP10).

CONCLUSIONS

We could not confirm our hypothesis that patients with NP have lower copeptin concentrations, although random blood sampling is not ideal. Further research is required to determine the use of copeptin in NP, perhaps in the identification of the desmopressin response.

Copeptin Levels Do Not Correlate With Cross-Clamping Time in Patients Undergoing Carotid Endarterectomy Under General Anesthesia

Copeptin is a sensitive and more stable surrogate marker for arginine vasopressin. In this study, we evaluated copeptin levels in carotid endarterectomy (CEA) patients, perioperatively, to determine whether copeptin levels can be related to carotid artery cross clamping (CC) time and to postoperative neurological outcomes. Copeptin, interleukin 6, C-reactive protein, cortisol, and brain natriuretic peptide were measured preoperatively (T1) and 3 hours postoperatively (T3) as well as intraoperatively (T2). We recruited 77 patients. Values of copeptin rose gradually over the observed times: T1 = 7.9 (6.4-9.6), T2 = 12.6 (9.3-16.8), and T3 = 72.3 (49.1-111.2) pmol/L. There was a significant difference for repeated measurement ( P = .000, P = .000, and P = .000). Duration of carotid artery CC during CEA does not affect postoperative copeptin level (CC ≤ 13 minutes: 106.8 ± 93.6 pmol/L, CC > 13 minutes: 96.7 ± 89.1 pmol/L; P = .634). Preoperative copeptin level was significantly higher in patients with ulcerated plaque morphology. Activation of the stress axis in patients undergoing CEA results in copeptin elevation. Duration of CC during CEA does not affect postoperative copeptin levels.

Relationship between plasma copeptin levels and complications of community-acquired pneumonia in preschool children

High plasma copeptin level has been associated with clinical outcomes after acute illness. The present study was undertaken to investigate the plasma copeptin concentrations in preschool children with community-acquired pneumonia (CAP) and to analyze the correlations of copeptin with CAP-related complications and pleural effusion. Plasma copeptin concentrations of 100 healthy children and 165 preschool children with CAP were measured. 35 children (21.2%) presented with complicated CAP and 28 children (17.0%) presented with pleural effusion. The admission copeptin levels were significantly increased in all patients (49.7 ± 21.4 pmol/L), children with complicated CAP (73.0 ± 16.9 pmol/L), those with uncomplicated CAP (43.4 ± 17.8 pmol/L), those with pleural effusion (70.9 ± 17.4 pmol/L) and those without pleural effusion (45.3 ± 19.5 pmol/L) compared with healthy control individuals (9.0 ± 2.7 pmol/L, all P<0.001). Multivariate logistic regression analysis showed that plasma copeptin levels were independently related to CAP-related complications (odds ratio 1.214, 95% confidence interval 1.104-1.872, P<0.001) and pleural effusion (odds ratio 1.226, 95% confidence interval 1.109-1.917, P<0.001). A receiver operating characteristic curve analysis showed plasma copeptin level better predicted CAP-related complications (area under curve 0.876, 95% confidence interval 0.815-0.922) and pleural effusion (area under curve 0.831, 95% confidence interval 0.765-0.885). Thus, plasma copeptin level may represent a novel biomarker for predicting CAP-related complications in preschool children.

Plasma copeptin concentration and outcome after pediatric traumatic brain injury

Higher plasma copeptin level has been associated with poor outcomes of critical illness. The present study was undertaken to investigate the plasma copeptin concentrations in children with traumatic brain injury (TBI) and to analyze the correlation of copeptin with disease outcome. Plasma copeptin concentrations of 126 healthy children and 126 children with acute severe TBI were measured by enzyme-linked immunosorbent assay. Twenty-one patients (16.7%) died and 38 patients (30.2%) had an unfavorable outcome (Glasgow Outcome Scale score of 1-3) at 6 months. Plasma copeptin level was obviously higher in patients than in healthy children (46.2±20.8 pmol/L vs. 9.6±3.0 pmol/L, P<0.001). Plasma copeptin level was identified as an independent predictor for 6-month mortality [odds ratio (OR) 1.261, 95% confidence interval (CI) 1.112-1.538, P=0.005] and unfavorable outcome (OR 1.313, 95% CI 1.146-1.659, P=0.003). The predictive value of copeptin was similar to that of Glasgow Coma Scale (GCS) score for 6-month mortality [area under curve (AUC) 0.832, 95% CI 0.755-0.892 vs. AUC 0.873, 95% CI 0.802-0.926, P=0.412] and unfavorable outcome (AUC 0.863, 95% CI 0.790-0.918 vs. AUC 0.885, 95% CI 0.816-0.935, P=0.596). Copeptin improved the AUC of GCS score for 6-month unfavorable outcome (AUC 0.929, 95% CI 0.869-0.967, P=0.013), but not for 6-month mortality (AUC 0.887, 95% CI 0.818-0.936, P=0.600). Thus, plasma copeptin level represents a novel biomarker for predicting 6-month clinical outcome in children with TBI.

Biomarkers in community-acquired pneumonia: a state-of-the-art review

Community-acquired pneumonia (CAP) exhibits mortality rates, between 20% and 50% in severe cases. Biomarkers are useful tools for searching for antibiotic therapy modifications and for CAP diagnosis, prognosis and follow-up treatment. This non-systematic state-of-the-art review presents the biological and clinical features of biomarkers in CAP patients, including procalcitonin, C-reactive protein, copeptin, pro-ANP (atrial natriuretic peptide), adrenomedullin, cortisol and D-dimers.

Prognostic value of copeptin: one-year outcome in patients with traumatic brain injury

High plasma copeptin level has been associated with one-month mortality after traumatic brain injury. However, not much is known regarding its relation with long-term outcome. Thus, we investigated the ability of copeptin to predict 1-year outcome in patients with traumatic brain injury. One hundred and six healthy controls and 106 patients with acute severe traumatic brain injury were included. Plasma samples were obtained on admission. Its concentration was measured by enzyme-linked immunosorbent assay. Forty-eight patients (45.3%) suffered from unfavorable outcome (Glasgow Outcome Scale score of 1-3) and 31 patients (29.2%) died in 1 year after traumatic brain injury. Upon admission, plasma copeptin level in patients was substantially higher than that in healthy controls. A forward stepwise logistic regression selected plasma copeptin level as an independent predictor for 1-year unfavorable outcome and mortality of patients. A receiver operating characteristic curve analysis showed plasma copeptin level predicted 1-year unfavorable outcome and mortality obviously. The predictive value of the copeptin concentration was thus similar to that of Glasgow Coma Scale score for the prediction of unfavorable outcome and mortality after 1 year. In a combined logistic-regression model, copeptin improved the area under curve of Glasgow Coma Scale score for the prediction of unfavorable outcome and mortality after 1 year, but the differences were not significant. Thus, copeptin level is a useful, complementary tool to predict functional outcome and mortality 1 year after traumatic brain injury.

Copeptin is associated with mortality in patients with traumatic brain injury

BACKGROUND

High serum copeptin levels are associated with injury severity after traumatic brain injury (TBI). However, not much is known regarding its relation with mortality. Thus, we sought to evaluate its relation with disease mortality.

METHODS

Fifty healthy controls and 94 patients with acute severe TBI were included. Plasma samples were obtained on admission and at days 1, 2, 3, 5, and 7. Its concentration was measured by enzyme-linked immunosorbent assay.

RESULTS

Twenty-six patients (27.7%) died from TBI in a month. After brain injury, plasma copeptin level in patients increased during the 6-hour period immediately, peaked in 24 hours, plateaued at day 2, decreased gradually thereafter, and was substantially higher than that in healthy controls during the 7-day period. A forward stepwise logistic regression selected plasma copeptin level (odds ratio, 1.008; 95% confidence interval, 1.002-1.014; p = 0.010) as an independent predictor for 1-month mortality of patients. A multivariate linear regression showed that plasma copeptin level was negatively associated with Glasgow Coma Scale (GCS) score (t = -7.161; p < 0.001). A receiver operating characteristic curve identified plasma copeptin cutoff level (451.8 pg/mL) that predicted 1-month mortality with the optimal sensitivity (88.5%) and specificity (75.0%) values (area under curve, 0.874; 95% confidence interval, 0.789-0.933; p < 0.001). The area under curve of plasma copeptin level was similar to that of GCS score (p = 0.299). However, copeptin did not statistically significantly improve the area under curve of GCS score (p = 0.413).

CONCLUSIONS

Increased plasma copeptin levels are associated with mortality after TBI.

Detection of copeptin in peripheral blood of patients with aneurysmal subarachnoid hemorrhage

Introduction

Copeptin has been proposed as a prognostic marker in acute illness. This study investigated the ability of copeptin to predict the disease outcome and cerebrovasospasm in the patients with aneurysmal subarachnoid hemorrhage.

Methods

In this retrospective study, 303 consecutive patients were included. Upon admission, plasma copeptin levels were measured by enzyme-linked immunosorbent assay. The end points were mortality after 1 year, in-hospital mortality, cerebrovasospasm and poor functional outcome (Glasgow Outcome Scale score of 1-3) after 1 year.

Results

Upon admission, plasma copeptin level in patients was statistically significantly higher than that in healthy controls. A multivariate analysis showed that plasma copeptin level was an independent predictor of poor functional outcome and mortality after 1 year, in-hospital mortality and cerebrovasospasm. A receiver operating characteristic curve showed that plasma copeptin level on admission predicted poor functional outcome and mortality after 1 year, in-hospital mortality and cerebrovasospasm of patients statistically significantly. The area under curve of the copeptin concentration was similar to those of World Federation of Neurological Surgeons (WFNS) score and modified Fisher score for the prediction of poor functional outcome and mortality after 1 year, and in-hospital mortality, but not for the prediction of cerebrovasospasm. In a combined logistic-regression model, copeptin improved the area under curve of WFNS score and modified Fisher score for the prediction of poor functional outcome after 1 year, but not for the prediction of mortality after 1 year, in-hospital mortality, and cerebrovasospasm.

Conclusions

Copeptin level is a useful, complementary tool to predict functional outcome and mortality after aneurysmal subarachnoid hemorrhage.

The Relationship between Blood Lactate and Survival following the Use of Adrenaline in the Treatment of Septic Shock

This prospective observational study evaluates the relationship between adrenaline, lactate and intensive care unit survival in septic shock. Forty patients requiring adrenaline therapy for a first episode of septic shock acquired >24 hours after admission to the intensive care unit had blood lactate levels measured two-hourly over a 24-hour period. Adrenaline therapy was escalated until target mean arterial pressure was reached. The lactate index was calculated as the ratio of maximum lactate increase to the adrenaline increase. Lactate increased from 2.3 to 2.9 mmol.l-1 (P=0.024) and the mean adrenaline increase was 0.14 μg.kg-1.minute-1. Peak lactate correlated with peak adrenaline (rho=0.34, P=0.032). Lactate index was the only independent predictor of survival after controlling for age and Acute Physiological and Chronic Health Evaluation II score (odds ratio 1.14, 95% confidence interval 1.03 to 1.26, P=0.009). A high lactate following adrenaline administration may be a beneficial and appropriate response.

Endocrine dysregulation in critically ill foals and horses

Critical illness challenges many endocrine homeostatic systems to overcome diseases, stress, and hostile conditions that threaten survival. Coordinated and consecutive responses by the autonomic nervous system, endocrine metabolic adaptations to mobilize and conserve energy and electrolytes, cardiovascular adjustments to maintain organ perfusion, and immunomodulation to overcome infections and inflammation are required. Because most admissions to equine intensive care units are related to horses with gastrointestinal disease and septic foals, most endocrine information during critical disease are generated from these populations. This article presents an overview on endocrine responses to critical illness in horses and foals and also some comparative information.

The peroxynitrite catalyst WW-85 improves pulmonary function in ovine septic shock

Systemic inflammatory response syndrome is associated with excessive production of nitric oxide (NO·) and superoxide (O2), forming peroxynitrite, which in turn, acts as a terminal mediator of cellular injury by producing cell necrosis and apoptosis. We examined the effect of the peroxynitrite decomposition catalyst, WW-85, in a sheep model of acute lung injury and septic shock. Eighteen sheep were operatively prepared and randomly allocated to the sham, control, or WW-85 group (n = 6 each). After a tracheotomy, acute lung injury was produced in the control and WW-85 groups by insufflation of four sets of 12 breaths of cotton smoke. Then, a 30-mL suspension of live Pseudomonas aeruginosa bacteria (containing 2 - 5 × 10¹¹ colony-forming units) was instilled into the lungs according to an established protocol. The sham group received only the vehicle (30 mL saline). The sheep were studied in awake state for 24 h and ventilated with 100% oxygen. WW-85 was administered 1 h after injury as bolus infusion (0.1 mg/kg), followed by a continuous infusion of 0.02 mg·kg⁻¹·h⁻¹ until the end of the 24-h experimental period. Compared with injured but untreated controls, WW-85-treated animals had significantly improved gas exchange, reductions in airway obstruction, shunt formation, lung myeloperoxidase concentrations, lung malondialdehyde concentrations, lung 3-nitrotyrosine concentrations, and plasma nitrate-to-nitrite levels. Animals treated with WW-85 exhibited less microvascular leakage and improvements in pulmonary function. These results provide evidence that blockade of the nitric oxide-peroxynitrite pathway improves disturbances from septic shock, as demonstrated in a clinically relevant ovine experimental model.

The peroxynitrite catalyst WW-85 improves microcirculation in ovine smoke inhalation injury and septic shock

This prospective, randomized, controlled experimental study examined the effects of the peroxynitrite decomposition catalyst WW-85 on global hemodynamics and regional microvascular blood flow (RMBF) in an established ovine model of septic shock following severe smoke inhalation injury. Twenty-one sheep were randomized into a sham group (no injury), a control group (smoke/sepsis), and a treatment group (smoke/sepsis/WW-85; n=7 each). WW-85 was administered 1h after injury as a bolus (0.1 mg/kg), followed by a continuous infusion of 0.02 mg/kg/h RMBF was analyzed using colored microspheres. All control animals developed a hypotensive, hyperdynamic circulation and increased plasma levels of nitrate/-nitrite (NOx). All hemodynamic variables and NOx levels were significantly improved in the treatment group. In visceral organs of controls, blood flow to trachea, ileum, and spleen significantly increased (p<0.05). Blood flow to kidneys and pancreas significantly decreased (p<0.05). Treatment with WW-85 stabilized blood flow to ileum, spleen, and kidneys on baseline levels and was significantly improved compared to controls (p<0.05). Cerebral blood flow deteriorated in controls, but was significantly improved in cerebral cortex, cerebellum, pons, medulla oblongata, and thalamus (p<0.05) by WW-85. These results provide evidence that WW-85 blocks NO production, thereby improving cardiovascular function and microcirculation.

Change in plasma copeptin level after acute spontaneous basal ganglia hemorrhage

High plasma copeptin levels are associated with mortality after intracerebral hemorrhage (ICH). However, there is a paucity of data available on whether copeptin is an independent prognostic marker of mortality. Thus, we sought to furthermore evaluate this relation. Thirty healthy controls and 86 patients with acute ICH were included. Plasma samples were obtained on admission and at days 1, 2, 3, 5, and 7 after ICH. Its concentration was measured by enzyme-linked immunosorbent assay. After ICH, plasma copeptin level in patients increased during the 6-h period immediately, peaked in 24h, decreased gradually thereafter, and was substantially higher than that in healthy controls during the 7-day period. A multivariate analysis showed plasma copeptin level was an independent predictor for 1-week mortality (odds ratio, 1.013; 95% confidence interval (CI), 1.003-1.023; P=0.009) and positively associated with hematoma volume (t=6.616, P<0.001). A receiver operating characteristic curve identified that a baseline plasma copeptin level >577.5pg/mL predicted 1-week mortality with 87.5% sensitivity and 72.2% specificity (area under curve (AUC), 0.873; 95% CI, 0.784-0.935). The AUC of the copeptin concentration was similar to those of Glasgow Coma Scale (GCS) scores and hematoma volumes (P=0.136 and 0.280). However, copeptin did not statistically significantly improve the AUCs of GCS scores and hematoma volumes (P=0.206 and 0.333). Hence, increased plasma copeptin level is associated with hematoma volume and an independent prognostic marker of mortality after ICH.

Recombinant human activated protein C attenuates cardiovascular and microcirculatory dysfunction in acute lung injury and septic shock

Introduction

This prospective, randomized, controlled, experimental animal study looks at the effects of recombinant human activated protein C (rhAPC) on global hemodynamics and microcirculation in ovine acute lung injury (ALI) and septic shock, resulting from smoke inhalation injury.

Methods

Twenty-one sheep (37 ± 2 kg) were operatively prepared for chronic study and randomly allocated to either the sham, control, or rhAPC group (n = 7 each). The control and rhAPC groups were subjected to insufflation of four sets of 12 breaths of cotton smoke followed by instillation of live Pseudomonas aeruginosa into both lung lobes, according to an established protocol. Healthy sham animals were not subjected to the injury and received only four sets of 12 breaths of room air and instillation of the vehicle (normal saline). rhAPC (24 μg/kg/hour) was intravenously administered from 1 hour post injury until the end of the 24-hour experiment. Regional microvascular blood flow was analyzed using colored microspheres. All sheep were mechanically ventilated with 100% oxygen, and fluid resuscitated with lactated Ringer's solution to maintain hematocrit at baseline levels.

Results

The rhAPC-associated reduction in heart malondialdehyde (MDA) and heart 3-nitrotyrosine (a reliable indicator of tissue injury) levels occurred parallel to a significant increase in mean arterial pressure and to a significant reduction in heart rate and cardiac output compared with untreated controls that showed a typical hypotensive, hyperdynamic response to the injury (P < 0.05). In addition, rhAPC significantly attenuated the changes in microvascular blood flow to the trachea, kidney, and spleen compared with untreated controls (P < 0.05 each). Blood flow to the ileum and pancreas, however, remained similar between groups. The cerebral blood flow as measured in cerebral cortex, cerebellum, thalamus, pons, and hypothalamus, was significantly increased in untreated controls, due to a loss of cerebral autoregulation in septic shock. rhAPC stabilized cerebral blood flow at baseline levels, as in the sham group.

Conclusions

We conclude that rhAPC stabilized cardiovascular functions and attenuated the changes in visceral and cerebral microcirculation in sheep suffering from ALI and septic shock by reduction of cardiac MDA and 3-nitrotyrosine.

Co-peptin: Role as a novel biomarker in clinical practice

BACKGROUND

Arginine vasopressin (AVP) is a key regulator of water balance, but its instability makes reliable measurement difficult and precludes its routine use. Co-peptin is the C-terminal part of the AVP precursor which plays an important role in the correct structural formation of the AVP precursor and its efficient proteolytic maturation. Because of its stoichiometric generation, co-peptin mirrors the release of AVP and measurement of more stable co-peptin may be an indicator of AVP levels.

METHOD

A comprehensive literature search was conducted from the websites of the National Library of Medicine (http://www.ncbl.nlm.nih.gov) and Pubmed Central, the US National Library of Medicine's digital archive of life sciences literature (http://www.pubmedcentral.nih.gov/). The data was assessed from books and journals that published relevant articles in this field.

RESULT

Recent and ongoing research indicates the diagnostic and prognostic roles of co-peptin in various clinical settings especially in critically ill patients.

CONCLUSION

Co-peptin levels are altered in various physiological and pathological conditions indicating its possible role as a biomarker. However, further research using co-peptin in various clinical settings will prove its cost-effectiveness and clinical usefulness.

Sympathetic overstimulation during critical illness: adverse effects of adrenergic stress

The term ''adrenergic'' originates from ''adrenaline'' and describes hormones or drugs whose effects are similar to those of epinephrine. Adrenergic stress is mediated by stimulation of adrenergic receptors and activation of post-receptor pathways. Critical illness is a potent stimulus of the sympathetic nervous system. It is undisputable that the adrenergic-driven ''fight-flight response'' is a physiologically meaningful reaction allowing humans to survive during evolution. However, in critical illness an overshooting stimulation of the sympathetic nervous system may well exceed in time and scope its beneficial effects. Comparable to the overwhelming immune response during sepsis, adrenergic stress in critical illness may get out of control and cause adverse effects. Several organ systems may be affected. The heart seems to be most susceptible to sympathetic overstimulation. Detrimental effects include impaired diastolic function, tachycardia and tachyarrhythmia, myocardial ischemia, stunning, apoptosis and necrosis. Adverse catecholamine effects have been observed in other organs such as the lungs (pulmonary edema, elevated pulmonary arterial pressures), the coagulation (hypercoagulability, thrombus formation), gastrointestinal (hypoperfusion, inhibition of peristalsis), endocrinologic (decreased prolactin, thyroid and growth hormone secretion) and immune systems (immunomodulation, stimulation of bacterial growth), and metabolism (increase in cell energy expenditure, hyperglycemia, catabolism, lipolysis, hyperlactatemia, electrolyte changes), bone marrow (anemia), and skeletal muscles (apoptosis). Potential therapeutic options to reduce excessive adrenergic stress comprise temperature and heart rate control, adequate use of sedative/analgesic drugs, and aiming for reasonable cardiovascular targets, adequate fluid therapy, use of levosimendan, hydrocortisone or supplementary arginine vasopressin.

Vasopressin in pediatric vasodilatory shock: a multicenter randomized controlled trial

RATIONALE

Vasopressin has been proposed as a potent vasoactive agent in the treatment of vasodilatory shock in adults and children. The objective of this trial was to evaluate the efficacy and safety of vasopressin as an adjunctive agent in pediatric vasodilatory shock.

METHODS

In this multicenter, double-blind trial, children with vasodilatory shock were randomized to receive low-dose vasopressin (0.0005-0.002 U/kg/min) or placebo in addition to open-label vasoactive agents. Vasoactive infusions were titrated to clinical endpoints of adequate perfusion. The primary outcome was time to vasoactive-free hemodynamic stability. Secondary outcomes included mortality, organ-failure-free days, length of critical care unit stay, and adverse events.

MEASUREMENTS AND MAIN RESULTS

Sixty-five of 69 children (94%) who were randomized received the study drug (33 vasopressin, 32 placebo) and were included in the analysis. There was no significant difference in the primary outcome between the vasopressin and placebo groups (49.7 vs. 47.1 hours; P = 0.85). There were 10 deaths (30%) in the vasopressin group and five (15.6%) in the placebo group (relative risk, 1.94; 95% confidence interval, 0.75-5.05; P = 0.24). There were no significant differences with respect to organ failure-free days (22 vs. 25.5 days; P = 0.11), ventilator-free days (16.5 23 days; P = 0.15), length of stay (8 vs. 8.5 days; P = 0.93), or adverse event rate ratios (12.0%; 95% confidence interval, -2.6 to 26.7; P = 0.15).

CONCLUSIONS

Low-dose vasopressin did not demonstrate any beneficial effects in this pediatric trial. Although not statistically significant, there was a concerning trend toward increased mortality. Clinical trial registered with www.controlled-trials.com (ISRCTN11597444).

Lung-protective effects of the metalloporphyrinic peroxynitrite decomposition catalyst WW-85 in interleukin-2 induced toxicity

Recombinant interleukin-2 (IL-2) therapy for malignancy is associated with a pulmonary vascular leakage syndrome (VLS) similar to that seen in sepsis. We investigated the possibility that the IL-2-induced VLS may be associated with the release of peroxynitrite (ONOO(-)), and used a model of IL-2-induced VLS in sheep to test the effects of the ONOO(-) decomposition catalyst WW-85. Eighteen sheep were chronically instrumented and randomly divided into three groups (n=6 per group): sham: lactated Ringer's solution, control: IL-2, and treatment: IL-2 and WW-85. Treatment with WW-85 significantly improved lung transvascular fluid flux, decreased lipid peroxidation, limited iNOS as well as PAR intensity, prevented tachycardia, and attenuated the increase in core body temperature resulting from IL-2 treatment. These findings suggest that ONOO(-) plays a pivotal role in the pathology of IL-2-induced pulmonary VLS, and that WW-85 may become a useful treatment option.

High versus standard-volume haemofiltration in hyperdynamic porcine peritonitis: effects beyond haemodynamics?

OBJECTIVE

The role of haemofiltration as an adjunctive treatment of sepsis remains a contentious issue. To address the role of dose and to explore the biological effects of haemofiltration we compared the effects of standard and high-volume haemofiltration (HVHF) in a peritonitis-induced model of porcine septic shock.

DESIGN AND SETTING

Randomized, controlled experimental study.

SUBJECTS

Twenty-one anesthetized and mechanically ventilated pigs.

INTERVENTIONS

After 12 h of hyperdynamic peritonitis, animals were randomized to receive either supportive treatment (Control, n = 7) or standard haemofiltration (HF 35 ml/kg per h, n = 7) or HVHF (100 ml/kg per hour, n = 7).

MEASUREMENTS AND RESULTS

Systemic and hepatosplanchnic haemodynamics, oxygen exchange, energy metabolism (lactate/pyruvate, ketone body ratios), ileal and renal cortex microcirculation and systemic inflammation (TNF-alpha, IL-6), nitrosative/oxidative stress (TBARS, nitrates, GSH/GSSG) and endothelial/coagulation dysfunction (von Willebrand factor, asymmetric dimethylarginine, platelet count) were assessed before, 12, 18, and 22 h of peritonitis. Although fewer haemofiltration-treated animals required noradrenaline support (86, 43 and 29% animals in the control, HF and HVHF groups, respectively), neither of haemofiltration doses reversed hyperdynamic circulation, lung dysfunction and ameliorated alterations in gut and kidney microvascular perfusion. Both HF and HVHF failed to attenuate sepsis-induced alterations in surrogate markers of cellular energetics, nitrosative/oxidative stress, endothelial injury or systemic inflammation.

CONCLUSIONS

In this porcine model of septic shock early HVHF proved superior in preventing the development of septic hypotension. However, neither of haemofiltration doses was capable of reversing the progressive disturbances in microvascular, metabolic, endothelial and lung function, at least within the timeframe of the study and severity of the model.

Copeptin, a novel prognostic biomarker in ventilator-associated pneumonia

Background

The present study sought to investigate the correlation of copeptin with the severity of septic status in patients with ventilator-associated pneumonia (VAP), and to analyze the usefulness of copeptin as a predictor of mortality in VAP.

Methods

The prospective observational cohort study was conducted in a teaching hospital. The subjects were 71 patients consecutively admitted to the intensive care unit from October 2003 to August 2005 who developed VAP. Copeptin levels were determined on day 0 and day 4 of VAP. Patients were followed for 28 days after the diagnosis, when they were considered survivors. Patients who died before day 28 were classified as nonsurvivors. There were no interventions.

Results

Copeptin levels increased from sepsis to severe sepsis and septic shock both on day 0 and day 4 (P = 0.001 and P = 0.009, respectively). Variables included in the univariable logistic regression analysis for mortality were age, gender, Acute Physiology and Chronic Health Evaluation II score and ln copeptin on day 0 and day 4. Mortality was directly related to ln copeptin levels on day 0 and day 4, with odds ratios of 2.32 (95% confidence interval, 1.25 to 4.29) and 2.31 (95% confidence interval, 1.25 to 4.25), respectively. In a multivariable logistic regression model for mortality, only ln copeptin on day 0 with odds ratio 1.97 (95% confidence interval, 1.06 to 3.69) and ln copeptin on day 4 with odds ratio 2.39 (95% confidence interval, 1.24 to 4.62) remained significant.

Conclusion

Our data demonstrate that copeptin levels increase progressively with the severity of sepsis and are independent predictors of mortality in VAP.

[Vasopressin as a rescue vasopressor agent. Treatment of selected cardiogenic shock states]

Vasodilatory shock is the most common form of shock in the critically ill patient. As a consequence of overwhelming and prolonged mediator production, vasodilatory shock can be the common final pathway of primary non-vasodilatory shock (e.g. cardiogenic or hypovolemic shock). A supplementary infusion of arginine vasopressin (AVP) showed beneficial effects on hemodynamics and potentially on the outcome in patients with vasodilatory shock due to sepsis or after major surgery. In this case series, successful administration of AVP in three surgical patients with primary cardiogenic shock forms is reported. The hemodynamic effects of AVP were comparable to those AVP-induced alterations described in septic shock and seem to be predominantly mediated by potent vasoconstriction and the facilitated reduction of higher, potentially toxic catecholamine doses. Thus, an AVP-induced decrease in heart rate and pulmonary arterial pressures may be particularly beneficial in patients with impaired cardiac function.

Midregional Pro-A-Type Natriuretic Peptide and Carboxy-Terminal Provasopressin May Predict Prognosis in Community-Acquired Pneumonia

Background: Markers to better assess severity of disease in patients with community-acquired pneumonia (CAP) would help improve medical care of this condition. The hemodynamic biomarkers carboxy-terminal provasopressin (CT-proAVP; copeptin) and midregional proatrial natriuretic peptide (MR-proANP) are increased under septic conditions, in which MR-proANP has been described as a prognostic predictor. We aimed to explore the diagnostic accuracy of MR-proANP and CT-proAVP to predict mortality in patients with CAP.

Methods: We conducted a prospective observational study of patients with CAP. We measured biomarkers in serum samples obtained at diagnosis and performed univariate and multivariate analyses to identify potential predictors of mortality.

Results: CT-proAVP and MR-proANP concentrations were measured in 173 patients. We found a positive correlation between pneumonia severity index (PSI) and MR-proANP (rs = 0.68, P &lt;0.0001) and between PSI and CT-proAVP (rs = 0.44, P &lt;0.0001). Median (interquartile range) CT-proAVP and MR-proANP values were 8.2 (5.3–16.8) and 73.6 (44.6–144.0) pmol/L, respectively. Nonsurvivors had significantly higher MR-proANP and CT-proAVP than survivors (median 259.0 vs 71.8 pmol/L, P = 0.01, and 24.9 vs 8.1 pmol/L, P = 0.03, respectively). In multivariate analysis including PSI, procalcitonin, C-reactive protein, lipopolysaccharide-binding protein, CT-proAVP, and MR-proANP concentrations, only CT-proAVP remained an independent predictor of death (odds ratio 1.05, P = 0.007). Cutoff values of &gt;18.9 pmol/L for CT-proAVP and &gt;227 pmol/L for MR-proANP showed the highest diagnostic accuracy to predict mortality.

Conclusions: CT-proAVP and MR-proANP may be used to predict prognosis in patients with CAP.

Glucose metabolism and catecholamines

Until now, catecholamines were the drugs of choice to treat hypotension during shock states. Catecholamines, however, also have marked metabolic effects, particularly on glucose metabolism, and the degree of this metabolic response is directly related to the beta2-adrenoceptor activity of the individual compound used. Under physiologic conditions, infusing catecholamine is associated with enhanced rates of aerobic glycolysis (resulting in adenosine triphosphate production), glucose release (both from glycogenolysis and gluconeogenesis), and inhibition of insulin-mediated glycogenesis. Consequently, hyperglycemia and hyperlactatemia are the hallmarks of this metabolic response. Under pathophysiologic conditions, the metabolic effects of catecholamines are less predictable because of changes in receptor affinity and density and in drug kinetics and the metabolic capacity of the major gluconeogenic organs, both resulting from the disease per se and the ongoing treatment. It is also well-established that shock states are characterized by a hypermetabolic condition with insulin resistance and increased oxygen demands, which coincide with both compromised tissue microcirculatory perfusion and mitochondrial dysfunction. This, in turn, causes impaired glucose utilization and may lead to inadequate glucose supply and, ultimately, metabolic failure. Based on the landmark studies on intensive insulin use, a crucial role is currently attributed to glucose homeostasis. This article reviews the effects of the various catecholamines on glucose utilization, both under physiologic conditions, as well as during shock states. Because, to date (to our knowledge), no patient data are available, results from relevant animal experiments are discussed. In addition, potential strategies are outlined to influence the catecholamine-induced effects on glucose homeostasis.

Ceftazidime improves hemodynamics and oxygenation in ovine smoke inhalation injury and septic shock

OBJECTIVE

To investigate ceftazidime in acute lung injury (ALI) and sepsis.

DESIGN AND SETTING

Prospective, randomized, controlled animal study in an investigational ICU at a university hospital.

INTERVENTIONS

Eighteen female Merino sheep were prepared for chronic study and subjected to smoke inhalation and septic challenge according to an established protocol.

MEASUREMENTS AND RESULTS

Whereas global hemodynamics and oxygenation remained stable in sham animals (no injury, no treatment), the injury contributed to a hypotensive-hyperdynamic circulation in the control group (smoke inhalation and sepsis, no treatment), as indicated by a significant increase in cardiac index) and heart rate and a drop in mean arterial pressure. Treatment with ceftazidime (smoke inhalation and sepsis, treatment group) stabilized cardiac index and heart rate and attenuated the decrease in mean arterial pressure. The deterioration in PaO2/FiO2 ratio and pulmonary shunt fraction (Qs/Qt) was significantly delayed and blunted by ceftazidime. At 24 h after injury a significant increase in airway obstruction scores of bronchi and bronchioles in both injured groups was observed. Ceftazidime significantly reduced airway obstruction vs. control animals. Whereas plasma nitrate/nitrite levels increased similarly in the two injured groups, lung 3-nitrotyrosine content remained at the baseline level in the ceftazidime group.

CONCLUSIONS

In ovine lung injury ceftazidime improves global hemodynamics and oxygenation not only by bacterial clearance but also via reduction in toxic nitrogen species such as 3-nitrotyrosine. Therefore ceftazidime appears as a clinically relevant adjunct in the common setting of sepsis-associated lung injury.

Review article: bacterial translocation in the critically ill--evidence and methods of prevention

BACKGROUND

Delayed sepsis, systemic inflammatory response syndrome (SIRS) and multiorgan failure remain major causes of morbidity and mortality on intensive care units. One factor thought to be important in the aetiology of SIRS is failure of the intestinal barrier resulting in bacterial translocation and subsequent sepsis.

AIM

This review summarizes the current knowledge about bacterial translocation and methods to prevent it.

METHODS

Relevant studies during 1966-2006 were identified from a literature search. Factors, which detrimentally affect intestinal barrier function, are discussed, as are methods that may attenuate bacterial translocation in the critically ill patient.

RESULTS

Methodological problems in confirming bacterial translocation have restricted investigations to patients undergoing laparotomy. There are only limited data available relating to specific interventions that might preserve intestinal barrier function or limit bacterial translocation in the intensive care setting. These can be categorized broadly into pre-epithelial, epithelial and post-epithelial interventions.

CONCLUSIONS

A better understanding of factors that influence translocation could result in the implementation of interventions which contribute to improved patient outcomes. Glutamine supplementation, targeted nutritional intervention, maintaining splanchnic flow, the judicious use of antibiotics and directed selective gut decontamination regimens hold some promise of limiting bacterial translocation. Further research is required.