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Future climate scenarios suggest an increased frequency of summer drought periods in the European Alpine Region. Drought can affect soil nitrogen (N) cycling, by altering N transformation rates, as well as the abundances of ammonia-oxidizing bacteria and archaea. However, the extent to which drought affects N cycling under in situ conditions is still controversial. The goal of this study was to analyse effects of drought on soil N turnover and ammonia-oxidizer abundances in soil without drought history. To this end we conducted rain-exclusion experiments at two differently managed mountain grassland sites, an annually mown and occasionally fertilized meadow and an abandoned grassland. Soils were sampled before, during and after drought and were analysed for potential gross rates of N mineralization, microbial uptake of inorganic N, nitrification, and the abundances of bacterial and archaeal ammonia-oxidizers based on gene copy numbers of the amoA gene (AOB and AOA, respectively). Drought induced different responses at the two studied sites. At the managed meadow drought increased NH4+ immobilization rates and NH4+ concentrations in the soil water solution, but led to a reduction of AOA abundance compared to controls. At the abandoned site gross nitrification and NO3− immobilization rates decreased during drought, while AOB and AOA abundances remained stable. Rewetting had only minor, short-term effects on the parameters that had been affected by drought. Seven weeks after the end of drought no differences to control plots could be detected. Thus, our findings demonstrated that in mountain grasslands drought had distinct transient effects on soil nitrogen cycling and ammonia-oxidizers, which could have been related to a niche differentiation of AOB and AOA with increasing NH4+ levels. However, the effect strength of drought was modulated by grassland management.

Objective To evaluate the association between arterial blood pressure (ABP) during the first 24 h and mortality in sepsis. Design Retrospective cohort study. Setting Multidisciplinary intensive care unit (ICU). Patients and participants A total of 274 septic patients. Interventions None. Measurements and results Hemodynamic, and laboratory parameters were extracted from a PDMS database. The hourly time integral of ABP drops below clinically relevant systolic arterial pressure (SAP), mean arterial pressure (MAP), and mean perfusion pressure (MPP = MAP − central venous pressure) levels was calculated for the first 24 h after ICU admission and compared with 28-day-mortality. Binary and linear regression models (adjusted for SAPS II as a measure of disease severity), and a receiver operating characteristic (ROC) analysis were applied. The areas under the ROC curve were largest for the hourly time integrals of ABP drops below MAP 60 mmHg (0.779 vs. 0.764 for ABP drops below MAP 55 mmHg; P ≤  0.01) and MPP 45 mmHg. No association between the hourly time integrals of ABP drops below certain SAP levels and mortality was detected. One or more episodes of MAP < 60 mmHg increased the risk of death by 2.96 (CI 95%, 1.06–10.36, P  = 0.04). The area under the ROC curve to predict the need for renal replacement therapy was highest for the hourly time integral of ABP drops below MAP 75 mmHg. Conclusions A MAP level ≥ 60 mmHg may be as safe as higher MAP levels during the first 24 h of ICU therapy in septic patients. A higher MAP may be required to maintain kidney function.

Acute pancreatitis is an inflammatory process of the pancreas with variable involvement of regional tissues and remote organs. This review gives a comprehensive overview of the aetiology, pathophysiology, diagnosis and therapy of acute pancreatitis relevant to the intensivist. Recent international guidelines on the management of acute pancreatitis are summarised. Eighty percent of acute pancreatitis episodes are related either to gallstones or to alcohol abuse. Independent of its aetiology, the pathophysiologic hallmark of acute pancreatitis is the premature activation of trypsin, which leads to massive pancreas inflammation, systemic overproduction of pro-inflammatory mediators and ultimately remote organ dysfunction. All guidelines agree that the diagnosis of acute pancreatitis should include clinical symptoms, increased serum amylase or lipase levels and/or characteristic findings on computed tomography. Endoscopic retrograde cholangiopancreatography is recommended as a causative therapy in patients with acute cholangitis or a strong suspicion of gallstones. All guidelines underline the importance of vigorous fluid resuscitation and supplemental oxygen therapy and prefer enteral over parenteral nutrition, with the majority favouring the nasojejunal route. In view of lacking scientific evidence, antibiotic prophylaxis to prevent infection of pancreatic necroses is discouraged by most guidelines. Computed tomography-guided fine needle aspiration is the technique of choice to differentiate between sterile and infected pancreas necrosis. While sterile pancreatic necrosis should be managed conservatively, infected pancreatic necrosis requires debridement and drainage supplemented by antibiotic therapy. Surgical necrosectomy is the traditional approach, but less invasive techniques (retroperitoneal or laparoscopic necrosectomy, computed tomography-guided percutaneous catheter drainage) may be equally effective.

Arginine-vasopressin (AVP) might be a potent vasopressor agent in catecholamine-resistant postcardiotomy shock. However, its use remains experimental because of considerations about deleterious effects on the heart. We report on the effects of continuous AVP-infusion on cardiac performance, biomarkers of myocardial ischemia, and systemic hemodynamics in catecholamine-resistant postcardiotomy shock. Retrospective study. Twenty-one-bed general and surgical intensive care unit. Forty-one patients with catecholamine-resistant postcardiotomy shock. Continuous infusion of AVP. Heart rate (HR), heart rhythm, mean arterial pressure (MAP), central venous pressure, mean pulmonary arterial pressure, cardiac index (CI), stroke volume index (SVI), left ventricular stroke work index (LVSWI), systemic vascular resistance (SVR) as well as milrinone and norepinephrine requirements were collected before and 1, 4, 12, 24, and 48 h after start of AVP infusion. Creatine kinase MB and troponin-I serum concentrations were measured daily. During AVP administration we observed a significant decrease in HR (-14.8%), milrinone (-17.5%), and norepinephrine requirements (-54.9%) as well as biomarkers of cardiac ischemia and a significant increase in LVSWI (+46.2%), MAP (+41.8%) and SVR (+60%). CI and SVI remained unchanged. Forty-five percent of postoperative new-onset tachyarrhythmias (TA) converted into sinus rhythm during AVP infusion. AVP was devoid of adverse effects on the heart in these patients with catecholamine-resistant postcardiotomy shock. The significant reduction in HR, vasopressor, and inotropic support suggest a substantial improvement in myocardial performance. These findings are supported by a significant decrease of cardiac enzymes and cardioversion of TA into sinus rhythm in 45.5% of patients with new-onset TA.

To determine the effects of increasing dosages of continuously infused arginine-vasopressin (AVP) on mucosal tissue oxygen tension and oxygen supply in an auto-perfused, innervated jejunal segment in an acute endotoxic porcine model. Prospective, randomized, experimental study. University hospital animal research laboratory. Jejunal mucosal tissue PO2 was measured employing two Clark-type surface oxygen electrodes. Oxygen saturation of jejunal microvascular hemoglobin was determined by tissue reflectance spectrophotometry. Systemic hemodynamic variables, mesenteric-venous and systemic acid base and blood gas variables and lactate measurements were recorded. Measurements were performed at baseline, after E. coli lipopolysaccharide (LPS) administration and at 20 min intervals during incremental AVP infusion (n=8; 0.014, 0.029, 0.057, 0.114 and 0.229 IU kg(-1) h(-1), respectively) or infusion of saline (n =8). LPS infusion leads to a significant (P<0.05) decrease of mucosal tissue oxygen tension (PO2muc, 24+/-3 to 12+/-2 mmHg) and microvascular hemoglobin oxygen saturation (HbO2, 38+/-4 to 21+/-4%). Mesenteric venous lactate level increased (2.4+/-0.3 to 4.7+/-1.7 mmol l(-1)), while mesenteric venous pH decreased (7.38+/-0.02 to 7.26+/-0.12), indicating tissue hypoxia. AVP significantly increased mean arterial pressure (MAP, 81+/-15 to 97+/-17 at 0.057 IU kg(-1) h(-1)). No differences in jejunal mucosal oxygenation occurred between study groups at any dosage during the experimental protocol. AVP administration did not further compromise mucosal tissue oxygen tension and oxygen supply in the acute phase of endotoxic pigs.

In this case report, the course of arginine vasopressin and copeptin, the stable C-terminal part of the arginine vasopressin precursor, is described during the period of critical illness in a septic shock patient. Arginine vasopressin and copeptin concentrations were substantially increased during the initial 36 hours of shock. Subsequently, both hormones continuously decreased, but exhibited another peak in response to stress during extubation. During restoration of cardiovascular stability, endogenous arginine vasopressin levels further decreased and obviously did not contribute to haemodynamic improvement. In contrast, the decrease in arginine vasopressin and copeptin can be at least partly explained by an improvement of cardiovascular function.

Extracorporeal membrane oxygenation (ECMO) can be a last resort treatment in acute respiratory distress syndrome after thoracic trauma. However, co-existent brain trauma is considered to be a contra-indication for ECMO. This is the first report on successful craniotomy under ECMO treatment in a multiply traumatized patient with severe thoracic and brain injuries. This successful treatment with beneficial neurological outcome suggests that ECMO therapy should not be withheld from severely injured patients with combined brain and thoracic trauma presenting with life-threatening hypoxemia. Moreover, even craniotomy may be performed during ECMO therapy without major bleeding and adverse effects on neurological function.

To compare spinal anesthesia with epidural anesthesia in patients undergoing surgery for vesicovaginal fistula (VVF) repair. Nonrandomized, prospective, clinical, pilot study. Rural African hospital with 165 beds. 60 ASA physical status I and II patients undergoing VVF repair surgery. 30 patients were included in each study group. Spinal (1.5-2 mL hyperbaric bupivacaine 0.75%) or lumbar epidural (20-24 mL bupivacaine 0.5%) anesthesia was administered to the patients. Demographics, quality of anesthesia, duration of postoperative analgesia, as well as preoperative, intraoperative, and postoperative data, were all recorded. Data were compared between study groups using unpaired Student's t test for continuous variables and χ 2 and Fisher's exact tests for categorical data. Quality of anesthesia was different between groups ( P = 0.009). Good anesthesia quality was significantly more frequent in the spinal (86.7%) than the epidural group (50%, P = 0.005). Postoperative analgesia quality was comparable ( P = 0.347). There were no differences between groups in hemodynamic parameters before, during, or after surgery. Spinal anesthesia proved to be the better anesthetic technique for VVF repair surgery when compared with epidural anesthesia in a rural, sub-Saharan African setting.