L-ornithine phenylacetate attenuates increased arterial and extracellular brain ammonia and prevents intracranial hypertension in pigs with acute liver failure

Hyperammonemia is a feature of acute liver failure (ALF), which is associated with increased intracranial pressure (ICP) and brain herniation. We hypothesized that a combination of L-ornithine and phenylacetate (OP) would synergistically reduce toxic levels of ammonia by (1) L-ornithine increasing glutamine production (ammonia removal) through muscle glutamine synthetase and (2) phenylacetate conjugating with the ornithine-derived glutamine to form phenylacetylglutamine, which is excreted into the urine. The aims of this study were to determine the effect of OP on arterial and extracellular brain ammonia concentrations as well as ICP in pigs with ALF (induced by liver devascularization). ALF pigs were treated with OP (L-ornithine 0.07 g/kg/hour intravenously; phenylbutyrate, prodrug for phenylacetate; 0.05 g/kg/hour intraduodenally) for 8 hours following ALF induction. ICP was monitored throughout, and arterial and extracellular brain ammonia were measured along with phenylacetylglutamine in the urine. Compared with ALF + saline pigs, treatment with OP significantly attenuated concentrations of arterial ammonia (589.6 +/- 56.7 versus 365.2 +/- 60.4 mumol/L [mean +/- SEM], P= 0.002) and extracellular brain ammonia (P= 0.01). The ALF-induced increase in ICP was prevented in ALF + OP-treated pigs (18.3 +/- 1.3 mmHg in ALF + saline versus 10.3 +/- 1.1 mmHg in ALF + OP-treated pigs;P= 0.001). The value of ICP significantly correlated with the concentration of extracellular brain ammonia (r(2) = 0.36,P< 0.001). Urine phenylacetylglutamine levels increased to 4.9 +/- 0.6 micromol/L in ALF + OP-treated pigs versus 0.5 +/- 0.04 micromol/L in ALF + saline-treated pigs (P< 0.001).Conclusion:L-Ornithine and phenylacetate act synergistically to successfully attenuate increases in arterial ammonia, which is accompanied by a significant decrease in extracellular brain ammonia and prevention of intracranial hypertension in pigs with ALF

A simple dummy liver assist device prolongs anhepatic survival in a porcine model of total hepatectomy by slight hypothermia

<p>Abstract</p> <p>Background</p> <p>Advances in intensive care support such as therapeutic hypothermia or new liver assist devices have been the mainstay of treatment attempting to bridge the gap from acute liver failure to liver transplantation, but the efficacy of the available devices in reducing mortality has been questioned. To address this issue, the present animal study was aimed to analyze the pure clinical effects of a simple extracorporeal dummy device in an anhepatic porcine model of acute liver failure.</p> <p>Methods</p> <p>Total hepatectomy was performed in ten female pigs followed by standardized intensive care support until death. Five animals (dummy group, n = 5) underwent additional cyclic connection to an extracorporeal dummy device which consisted of a plasma separation unit. The separated undetoxified plasma was completely returned to the pigs circulation without any plasma substitution or exchange in contrast to animals receiving intensive care support alone (control group, n = 5). All physiological parameters such as vital and ventilation parameters were monitored electronically; laboratory values and endotoxin levels were measured every 8 hours.</p> <p>Results</p> <p>Survival of the dummy device group was 74 ± 6 hours in contrast to 53 ± 5 hours of the control group which was statistically significant (p < 0.05). Body temperature 24 hours after hepatectomy was significantly lower (36.5 ± 0.5°C vs. 38.2 ± 0.7°C) in the dummy device group. Significant lower values were measured for blood lactate (1.9 ± 0.2 vs. 2.5 ± 0.5 mM/L) from 16 hours, creatinine (1.5 ± 0.2 vs. 2.0 ± 0.3 mg/dL) from 40 hours and ammonia (273 ± 122 vs. 1345 ± 700 μg/dL) from 48 hours after hepatectomy until death. A significant rise of endotoxin levels indicated the onset of sepsis at time of death in 60% (3/5) of the dummy device group animals surviving beyond 60 hours from hepatectomy.</p> <p>Conclusions</p> <p>Episodes of slight hypothermia induced by cyclic connection to the extracorporeal dummy device produced a significant survival benefit of more than 20 hours through organ protection and hemodynamic stabilisation. Animal studies which focus on a survival benefit generated by liver assist devices should especially address the aspect of slight transient hypothermia by extracorporeal cooling.</p

Enhanced recovery after surgery: are we ready, and can we afford not to implement these pathways for patients undergoing radical cystectomy?

Enhanced recovery after surgery (ERAS) for radical cystectomy seems logical, but our study has shown a paucity in the level of clinical evidence. As part of the ERAS Society, we welcome global collaboration to collect evidence that will improve patient outcomes

Glutamine and glutathione at ICU admission in relation to outcome

Glutamine depletion is demonstrated to be an independent predictor of hospital mortality in ICU (intensive care unit) patients. Today glutamine supplementation is recommended to ICU patients on parenteral nutrition. In addition to glutamine, glutathione may be a limiting factor in ICU patients with MOF (multiple organ failure). To study the prevalence of glutamine and glutathione depletion an observational study was performed. The results were analysed in relation to mortality and the conventional predictors of mortality outcome, APACHE II (Acute Physiology and Chronic Health Evaluation II) and SOFA (Sequential Organ Failure Assessment). Consecutive patients admitted to the ICU at Karolinska University Hospital Huddinge were studied. Patient admission scoring of APACHE II and SOFA were registered as well as mortality up to 6 months. Plasma glutamine concentration and whole blood glutathione status at admittance were analysed. The admission plasma glutamine concentrations were totally independent of the conventional risk scoring at admittance, and a subnormal concentration was an independent predictor of mortality. In addition, glutathione redox status was also an independent mortality predictor, but here a normal ratio was the risk factor. In both cases the mortality risk was mainly confined to the post-ICU period. A low plasma concentration of glutamine at ICU admission is an independent risk factor for post-ICU mortality. The possible benefit of extending glutamine supplementation post-ICU should be evaluated prospectively

Serum S100B levels after meningioma surgery: A comparison of two laboratory assays

<p>Abstract</p> <p>Background</p> <p>S100B protein is a potential biomarker of central nervous system insult. This study quantitatively compared two methods for assessing serum concentration of S100B.</p> <p>Methods</p> <p>A prospective, observational study performed in a single tertiary medical center. Included were fifty two consecutive adult patients undergoing surgery for meningioma that provided blood samples for determination of S100B concentrations. Eighty samples (40 pre-operative and 40 postoperative) were randomly selected for batch testing. Each sample was divided into two aliquots. These were analyzed by ELISA (Sangtec) and a commercial kit (Roche Elecsys^®) for S100B concentrations. Statistical analysis included regression modelling and Bland-Altman analysis.</p> <p>Results</p> <p>A parsimonious linear model best described the prediction of commercial kit values by those determined by ELISA (y = 0.045 + 0.277*x, x = ELISA value, R²= 0.732). ELISA measurements tended to be higher than commercial kit measurements. This discrepancy increased linearly with increasing S100B concentrations. At concentrations above 0.7 μg/L the paired measurements were consistently outside the limits of agreement in the Bland-Altman display. Similar to other studies that used alternative measurement methods, sex and age related differences in serum S100B levels were not detected using the Elecsys^®(p = 0.643 and 0.728 respectively).</p> <p>Conclusion</p> <p>Although a generally linear relationship exists between serum S100B concentrations measured by ELISA and a commercially available kit, ELISA values tended to be higher than commercial kit measurements particularly at concentrations over 0.7 μg/L, which are suggestive of brain injury. International standardization of commercial kits is required before the predictive validity of S100B for brain damage can be effectively assessed in clinical practice.</p

Enhanced Recovery After Surgery (ERAS) for gastrointestinal surgery, part 2:consensus statement for anaesthesia practice

Background The present interdisciplinary consensus review proposes clinical considerations and recommendations for anaesthetic practice in patients undergoing gastrointestinal surgery with an Enhanced Recovery after Surgery (ERAS) programme. Methods Studies were selected with particular attention being paid to meta-analyses, randomized controlled trials and large prospective cohort studies. For each item of the perioperative treatment pathway, available English-language literature was examined and reviewed. The group reached a consensus recommendation after critical appraisal of the literature. Results This consensus statement demonstrates that anaesthesiologists control several preoperative, intraoperative and postoperative ERAS elements. Further research is needed to verify the strength of these recommendations. Conclusions Based on the evidence available for each element of perioperative care pathways, the Enhanced Recovery After Surgery (ERAS ®) Society presents a comprehensive consensus review, clinical considerations and recommendations for anaesthesia care in patients undergoing gastrointestinal surgery within an ERAS programme. This unified protocol facilitates involvement of anaesthesiologists in the implementation of the ERAS programmes and allows for comparison between centres and it eventually might facilitate the design of multi-institutional prospective and adequately powered randomized trials

Anti-Inflammatory actions of vitamin K

This book serves as a comprehensive survey of the impact of vitamin K2 on cellular functions and organ systems, indicating that vitamin K2 plays an important role in the differentiation/preservation of various cell phenotypes and as a stimulator and/or mediator of interorgan cross talk. Vitamin K2 binds to the transcription factor SXR/PXR, thus acting like a hormone (very much in the same manner as vitamin A and vitamin D). Therefore, vitamin K2 affects a multitude of organ systems, and it is reckoned to be one positive factor in bringing about ""longevity"" to the human body, e.g., supporting the functions/health of different organ systems, as well as correcting the functioning or even ""curing"" ailments striking several organs in our body. Vitamin K2 - Vital for Health and Wellbeing has been produced and distributed through the support from Kappa Bioscience, Norway. </span