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Abstract Residents in training, medical students and other staff in surgical sector, emergency room (ER) and intensive care unit (ICU) or Burn Unit face a multitude of questions regarding burn care. Treatment of burns is not always straightforward. Furthermore, National and International guidelines differ from one region to another. On one hand, it is important to understand pathophysiology, classification of burns, surgical treatment, and the latest updates in burn science. On the other hand, the clinical situation for treating these cases needs clear guidelines to cover every single aspect during the treatment procedure. Thus, 10 questions have been organised and discussed in a step-by-step form in order to achieve the excellence of education and the optimal treatment of burn injuries in the first 24 hours. These 10 questions will clearly discuss referral criteria to the burn unit, primary and secondary survey, estimation of the total burned surface area (%TBSA) and the degree of burns as well as resuscitation process, routine interventions, laboratory tests, indications of Bronchoscopy and special considerations for Inhalation trauma, immediate consultations and referrals, emergency surgery and admission orders. Understanding and answering the 10 questions will not only cover the management process of Burns during the first 24 hours but also seems to be an interactive clear guide for education purpose.

Abstract Background Piezoresistive pressure measurement technique (PRM) has previously been applied for direct IAP measurement in a porcine model using two different devices. Aim of this clinical study was to assess both devices regarding complications, reliability and agreement with IVP in patients undergoing elective abdominal surgery. Methods A prospective cohort study was performed in 20 patients randomly scheduled to receive PRM either by a Coach®-probe or an Accurate++®-probe (both MIPM, Mammendorf, Germany). Probes were placed on the greater omentum and passed through the abdominal wall paralleling routine drainages. PRM was compared with IVP measurement by t-testing and by calculating mean difference as well as limits of agreement (LA). Results There were no probe related complications. Due to technical limitations, data could be collected in 3/10 patients with Coach® and in 7/10 patients with Accurate++®. Analysis was carried out only for Accurate++®. Mean values did not differ to mean IVP values. Mean difference to IVP was 0.1 ± 2.8 mmHg (LA: -5.5 to 5.6 mmHg). Conclusion Direct IAP measurement was clinically uneventful. Although results of Accurate++® were comparable to IVP, the device might be too fragile for IAP measurements in the clinical setting. Local ethical committee trial registration: EK2024

Abstract Background The gold standard for assessment of intraabdominal pressure (IAP) is via intravesicular pressure measurement (IVP). This accepted technique has some inherent problems, e.g. indirectness. Aim of this clinical study was to assess direct IAP measurement using an air-capsule method (ACM) regarding complications risks and agreement with IVP in patients undergoing abdominal surgery. Methods A prospective cohort study was performed in 30 patients undergoing elective colonic, hepatic, pancreatic and esophageal resection. For ACM a Probe 3 (Spiegelberg®, Germany) was placed on the greater omentum. It was passed through the abdominal wall paralleling routine drainages. To compare ACM with IVP t-testing was performed and mean difference as well as limits of agreement were calculated. Results ACM did not lead to complications particularly with regard to organ lesion or surgical site infection. Mean insertion time of ACM was 4.4 days (min-max: 1–5 days). 168 pairwise measurements were made. Mean ACM value was 7.9 ± 2.7 mmHg while mean IVP was 8.4 ± 3.0 mmHg (n.s). Mean difference was 0.4 mmHg ± 2.2 mmHg. Limits of agreement were -4.1 mmHg to 5.1 mmHg. Conclusion Using ACM, direct IAP measurement is feasible and uncomplicated. Associated with relatively low pressure ranges (

The gold standard for assessment of intraabdominal pressure (IAP) is via intravesicular pressure measurement (IVP). This accepted technique has some inherent problems, e.g. indirectness. Aim of this clinical study was to assess direct IAP measurement using an air-capsule method (ACM) regarding complications risks and agreement with IVP in patients undergoing abdominal surgery.~Background~Background~A prospective cohort study was performed in 30 patients undergoing elective colonic, hepatic, pancreatic and esophageal resection. For ACM a Probe 3 (Spiegelberg, Germany) was placed on the greater omentum. It was passed through the abdominal wall paralleling routine drainages. To compare ACM with IVP t-testing was performed and mean difference as well as limits of agreement were calculated.~Methods~Methods~ACM did not lead to complications particularly with regard to organ lesion or surgical site infection. Mean insertion time of ACM was 4.4 days (min-max: 1-5 days). 168 pairwise measurements were made. Mean ACM value was 7.9 +/- 2.7 mmHg while mean IVP was 8.4 +/- 3.0 mmHg (n.s). Mean difference was 0.4 mmHg +/- 2.2 mmHg. Limits of agreement were -4.1 mmHg to 5.1 mmHg.~Results~Results~Using ACM, direct IAP measurement is feasible and uncomplicated. Associated with relatively low pressure ranges (<17 mmHg), results are comparable to bladder pressure measurement.~Conclusion~Conclusions [ABSTRACT FROM AUTHOR]

Objective: Cerebral vasospasm and the resultant delayed cerebral infarction is a significant source of mortality following aneurysmal SAH. Vasospasm is currently detected using invasive or expensive imaging at regular intervals in patients following SAH, thus posing a risk of complications following the procedure and financial burden on these patients. Currently, there is no blood-based test to detect vasospasm., Methods: PubMed, Web of Science, and Embase databases were systematically searched to retrieve studies related to cerebral vasospasm, aneurysm rupture, and biomarkers. The study search dated from 1997 to 2022. Data from eligible studies was extracted and then summarized., Results: Out of the 632 citations screened, only 217 abstracts were selected for further review. Out of those, only 59 full text articles met eligibility and another 13 were excluded., Conclusions: We summarize the current literature on the mechanism of cerebral vasospasm and delayed cerebral ischemia, specifically studies relating to inflammation, and provide a rationale and commentary on a hypothetical future bloodbased test to detect vasospasm. Efforts should be focused on clinical-translational approaches to create such a test to improve treatment timing and prediction of vasospasm to reduce the incidence of delayed cerebral infarction., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors. Published by Elsevier Inc.)

Background: In an effort to minimize positive margins and subsequent re-excision after breast conserving surgery (BCS), many providers and facilities have implemented either a Full Cavity Shave (FCS) approach or adding the MarginProbe Radiofrequency Spectroscopy System., Objective: We sought to create a functioning Pro-Forma for use by facilities and payers to evaluate and compare the cost savings of implementing FCS or MarginProbe based on personalized variable inputs., Methods: A decision tree demonstrating three possible surgical pathways, BCS, BCS + FCS, and BCS + MarginProbe was developed with clinical inputs for re-excision rate, mastectomy as 2nd surgery, rate of reconstruction, and rate of 3rd surgery derived by a literature review. A surgical pathway cost formula was created using the decision tree and financial inputs derived by utilizing the nation's largest database of privately billed health insurance claims and Medicare claims data (fairhealth.org). Using the surgical pathway formula and financial inputs, a customizable Pro-Forma was created for immediate cost savings analysis of BCS + FCS and BCS + Marginprobe using variable inputs. Costs are from the perspective of third-party payers., Results: Utilizing MarginProbe to reduce re-excisions for positive margins can be associated with better cost-savings than FCS due to the increased pathology processing costs by using an FCS approach. The reduction in re-excision provided by both FCS and MarginProbe offset their increased expense to various degrees with cost savings of each method improving as baseline re-excisions rates increase, until ultimately each may become cost-neutral or cost-prohibitive when compared to BCS alone. Our data suggest that in the privately insured population, MarginProbe provides a cost-savings over BCS alone when baseline re-excision rates are over 20% and that FCS becomes cost-saving when baseline re-excision rates are over 29%. For Medicare patients, MarginProbe provides a cost-savings when baseline re-excision rates exceed 34%, and FCS becomes cost-saving for re-excision rates over 52%. Our Pro-Forma allows an individual provider or institution to evaluate the cost savings of the FCS approach and/or utilization of the MarginProbe device such that the additional cost or cost-savings of utilizing one or both of these methods can be quickly calculated based on their facility's volume and baseline re-excision rate., Conclusions: Our data suggest that utilizing either an FCS approach or the MarginProbe radiofrequency spectroscopy system may be a cost-saving solution to reducing the rate of re-excisions depending on a facility or practice's surgical volume and baseline re-excision rate. The degree to which each of these interventions provides an added cost or cost-savings to healthcare payers can be evaluated by utilizing the Pro-Forma outlined herein with customizable variable inputs., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Dicobalt hexacarbonyl 5-alkynyl furopyrimidine nucleoside analogs, with 4-methylphenyl ( p -tolyl) and 4-pentylphenyl substituents attached at the C-6 base position, designed in the form of ribose acetyl esters, were synthesized (42-96%). Attached at the C-5 position were propargyl alcohol, its methyl ether and acetate derivatives, butynol, and the 4-methylphenyl- ( p -tolyl) and 4-pentylphenyl-substituted alkynyl groups, which were coordinated to a dicobalt hexacarbonyl unit. The structure of 5-(3-acetoxyprop-1-yn-1-yl)-6- p -tolyl-2'-deoxyribofuranosyl-furo[2,3- d ]pyrimidin-2-one was determined by X-ray crystallography. Density functional theory calculations performed on the corresponding derivative yielded geometric parameters for the dicobalt hexacarbonyl adduct of this ligand. The cytotoxic activity of each of dicobalt modified nucleosides on cancer cells of different phenotypes was determined in vitro . The investigated compounds showed antiproliferative effects with median inhibitory concentration (IC 50 ) values in the ranges of 14-90 and 9-50 μM for HeLa and K562 cells, respectively. The formation of reactive oxygen species in the presence of modified nucleosides was determined in K562 cells. The results indicate that the mechanism of action for the studied compounds may be related to the induction of oxidative stress., Competing Interests: The authors declare no competing financial interest., (© 2023 American Chemical Society.)

This review includes recent developments in the synthesis of benzo[4,5]imidazo[2,1- a ]isoquinolines with particular attention given to categorizing protocols based on the structural features of the ring architecture and crystallographically characterized reaction products.

This work shows that S atom substitution in phosphate controls the directionality of hole transfer processes between the base and sugar-phosphate backbone in DNA systems. The investigation combines synthesis, electron spin resonance (ESR) studies in supercooled homogeneous solution, pulse radiolysis in aqueous solution at ambient temperature, and density functional theory (DFT) calculations of in-house synthesized model compound dimethylphosphorothioate (DMTP(O - )═S) and nucleotide (5'- O -methoxyphosphorothioyl-2'-deoxyguanosine (G-P(O - )═S)). ESR investigations show that DMTP(O - )═S reacts with Cl 2 •- to form the σ 2 σ* 1 adduct radical -P-S[Formula: see text]Cl, which subsequently reacts with DMTP(O - )═S to produce [-P-S[Formula: see text]S-P-] - . -P-S[Formula: see text]Cl in G-P(O - )═S undergoes hole transfer to Gua, forming the cation radical (G •+ ) via thermally activated hopping. However, pulse radiolysis measurements show that DMTP(O - )═S forms the thiyl radical (-P-S • ) by one-electron oxidation, which did not produce [-P-S[Formula: see text]S-P-] - . Gua in G-P(O - )═S is oxidized unimolecularly by the -P-S • intermediate in the sub-picosecond range. DFT thermochemical calculations explain the differences in ESR and pulse radiolysis results obtained at different temperatures.

Background: Sepsis is associated with capillary leakage and vasodilatation and leads to hypotension and tissue hypoperfusion. Early plasma volume replacement is required to achieve haemodynamic stability (HDS) and maintain adequate tissue oxygenation. The right choice of fluids to be used for plasma volume replacement (colloid or crystalloid solutions) is still a matter of debate, and large trials investigating the use of colloid solutions containing gelatine are missing. This study aims to investigate the efficacy and safety of plasma volume replacement using either a combined gelatine-crystalloid regime (1:1 ratio) or a pure crystalloid regime., Methods: This is a prospective, controlled, randomized, double-blind, international, multicentric phase IV study with two parallel groups that is planned to be conducted at European intensive care units (ICUs) in a population of patients with hypovolaemia in severe sepsis/septic shock. A total of 608 eligible patients will be randomly assigned to receive either a gelatine-crystalloid regime (Gelaspan® 4% and Sterofundin® ISO, B. Braun Melsungen AG, in a 1:1 ratio) or a pure crystalloid regime (Sterofundin® ISO) for plasma volume replacement. The primary outcome is defined as the time needed to achieve HDS. Plasma volume replacement will be target-controlled, i.e. fluids will only be administered to volume-responsive patients. Volume responsiveness will be assessed through passive leg raising or fluid challenges. The safety and efficacy of both regimens will be assessed daily for 28 days or until ICU discharge (whichever occurs first) as the secondary outcomes of this study. Follow-up visits/calls will be scheduled on day 28 and day 90., Discussion: This study aims to generate evidence regarding which regimen-a gelatine-crystalloid regimen or a pure crystalloid regimen-is more effective in achieving HDS in critically ill patients with hypovolaemia. Study participants in both groups will benefit from the increased safety of target-controlled plasma volume replacement, which prevents fluid administration to already haemodynamically stable patients and reduces the risk of harmful fluid overload., Trial Registration: The European clinical trial database EudraCT 2015-000057-20 and the ClinicalTrials.gov Protocol Registration and Results System ClinicalTrials.gov NCT02715466 . Registered on 17 March 2016.

We report the case of letrozole-induced radiation recall dermatitis (RRD) in a patient with a remote history of radiation therapy. There is only one previously known case of RRD triggered by letrozole in a patient with a recent (<3 month) history of radiation. Previously, only four other cases of aromatase-inhibitor-induced RRD have been reported. This case is significant for cancer care teams considering personalized treatments. In addition, improved long-term outcomes in cancer patients may lead to increases in and underdiagnoses of RRD. Likewise, RRD is patient specific, exacerbating health concerns, and can be difficult to recognize without proper awareness, documentation, and classification of triggering drugs. The authors hope to address these issues in this report.

ER+/PR- (estrogen receptor positive and progesterone receptor negative) tumors constitute only a small portion of the breast cancer population. Patients with ER+/PR- tumors, however, are characterized by worse survival compared to patients with ER+/PR+ (estrogen receptor positive and progesterone receptor positive) tumors. Controversy exists regarding the efficacy of hormone blocking therapy for patients with ER+/PR- tumors. The NCDB was queried between 2004 and 2015, and patients with invasive ER+/PR- tumors were identified. We employed univariate Cox proportional hazards to compare outcomes among patients that did or did not receive hormone blocking therapy. We identified 138,398 patients with invasive ER+/PR- tumors, 32,044 (23%) of whom did not receive hormone blocking therapy. The reasons for not receiving hormone blocking therapy included contraindications to treatment, death, patient refusal, and unknown. There were no significant differences in race, income quartile, or education quartile between patients who did and did not receive hormone blocking therapy. Patients who did not receive hormone blocking therapy underwent surgical assessment of the axilla more frequently than those who did receive hormone therapy. Our analysis demonstrated that hormone blocking therapy administration was associated with increased overall survival for up to 10 years of follow up (HR: 0.58; 95% CI: 0.56-0.59, p < 0.001). Hormone blocking therapy may be associated with increased survival for breast cancer patients with ER+/PR- tumors. Although this benefit may last for years after completion of the course, up to 25% of patients do not receive this treatment. Strategies to increase the utilization and adherence to hormone blocking therapy regimens may improve patient survival outcomes.

Background: RESP score and PRESERVE score have been validated for veno-venous Extracorporeal Membrane Oxygenation in severe ARDS to assume individual mortality risk. ARDS patients with low-flow Extracorporeal Carbon Dioxide Removal, especially pumpless Extracorporeal Lung Assist, have also a high mortality rate, but there are no validated specific or general outcome scores. This retrospective study tested whether these established specific risk scores can be validated for pumpless Extracorporeal Lung Assist in ARDS patients in comparison to a general organ dysfunction score, the SOFA score., Methods: In a retrospective single center cohort study we calculated and evaluated RESP, PRESERVE, and SOFA score for 73 ARDS patients with pumpless Extracorporeal Lung Assist treated between 2002 and 2016 using the XENIOS iLA Membrane Ventilator. Six patients had a mild, 40 a moderate and 27 a severe ARDS according to the Berlin criteria. Demographic data and hospital mortality as well as ventilator settings, hemodynamic parameters, and blood gas measurement before and during extracorporeal therapy were recorded., Results: Pumpless Extracorporeal Lung Assist of mechanical ventilated ARDS patients resulted in an optimized lung protective ventilation, significant reduction of P aCO2 , and compensation of acidosis. Scoring showed a mean score of alive versus deceased patients of 3 ± 1 versus - 1 ± 1 for RESP (p < 0.01), 3 ± 0 versus 6 ± 0 for PRESERVE (p < 0.05) and 8 ± 1 versus 10 ± 1 for SOFA (p < 0.05). Using receiver operating characteristic curves, area under the curve (AUC) was 0.78 (95% confidence interval (CI) 0.67-0.89, p < 0.01) for RESP score, 0.80 (95% CI 0.70-0.90, p < 0.0001) for PRESERVE score and 0.66 (95% CI 0.53-0.79, p < 0.05) for SOFA score., Conclusions: RESP and PRESERVE scores were superior to SOFA, as non-specific critical care score. Although scores were developed for veno-venous ECMO, we could validate RESP and PRESERVE score for pumpless Extracorporeal Lung Assist. In conclusion, RESP and PRESERVE score are suitable to estimate mortality risk of ARDS patients with an arterio-venous pumpless Extracorporeal Carbon Dioxide Removal.

Dicobalt hexacarbonyl nucleoside complexes of propargyl ether or esters of 5-substituted uridines react with diverse C-nucleophiles. Synthetic outcomes confirmed that the Nicholas reaction can be carried out in a nucleoside presence, leading to a divergent synthesis of novel metallo-nucleosides enriched with alkene, arene, arylketo, and heterocyclic functions, in the deoxy and ribo series., (Copyright © 2020, Kaczmarek et al.; licensee Beilstein-Institut.)

Reactions of dicobalt octacarbonyl [Co 2 (CO) 8 ] with 2'-deoxy-5-oxopropynyluridines and related compounds gave dicobalt hexacarbonyl nucleoside complexes (83-31 %). The synthetic outcomes were confirmed by X-ray structure determination of dicobalt hexacarbonyl 2'-deoxy-5-(4-hydroxybut-1-yn-1-yl)uridine, which exhibits intermolecular hydrogen bonding between a modified base and ribose. The electronic structure of this compound was characterized by the DFT calculations. The growth inhibition of HeLa and K562 cancer cell lines by organometallic nucleosides was examined and compared to that by alkynyl nucleoside precursors. Coordination of the dicobalt carbonyl moiety to the 2'-deoxy-5-alkynyluridines led to a significant increase in the cytotoxic potency. The cobalt compounds displayed antiproliferative activities with median inhibitory values (IC 50 ) in the range of 20 to 80 μm for the HeLa cell line and 18 to 30 μm for the K562 cell line. Coordination of an acetyl-substituted cobalt nucleoside was expanded by using the 1,1-bis(diphenylphosphino)methane (dppm) ligand, which exhibited cytotoxicity at comparable levels. The formation of reactive oxygen species in the presence of cobalt compounds was determined in K562 cells. The results indicate that the mechanism of action for most antiproliferative cobalt compounds may be related to the induction of oxidative stress.

Facilitation of early spontaneous breathing activity is the most important measure to shorten weaning and avoid ventilator-induced lung injury and diaphragmatic injury in mechanically ventilated patients. However, the optimal degree of spontaneous muscle activity and ventilator support remains to be determined. Furthermore, effectiveness in relation to the pathophysiology of respiratory failure is unclear. In this regard the experimental study by Saddy and colleagues reveals interesting insights into the pathophysiology of ventilator-induced injury. More important, their results raise important questions that should be evaluated in further studies.

Introduction: Treatment of acute lung injury (ALI) remains an unsolved problem in intensive care medicine. As simvastatin exerts protective effects in inflammatory diseases we explored its effects on development of ALI and due to the importance of neutrophils in ALI also on neutrophil effector functions., Methods: C57Bl/6 mice were exposed to aerosolized LPS (500 µg/ml) for 30 min. The count of alveolar, interstitial, and intravasal neutrophils were assessed 4 h later by flow cytometry. Lung permeability changes were assessed by FITC-dextran clearance and albumin content in the BAL fluid. In vitro, we analyzed the effect of simvastatin on neutrophil adhesion, degranulation, apoptosis, and formation of reactive oxygen species. To monitor effects of simvastatin on bacterial clearance we performed phagocytosis and bacterial killing studies in vitro as well as sepsis experiments in mice., Results: Simvastatin treatment before and after onset of ALI reduces neutrophil influx into the lung as well as lung permeability indicating the protective role of simvastatin in ALI. Moreover, simvastatin reduces the formation of ROS species and adhesion of neutrophils without affecting apoptosis, bacterial phagocytosis and bacterial clearance., Conclusion: Simvastatin reduces recruitment and activation of neutrophils hereby protecting from LPS-induced ALI. Our results imply a potential role for statins in the management of ALI.

Background: In study, we investigated the effects of different tidal volumes on cerebral tissue oxygenation and cerebral metabolism in a porcine model of acute lung injury (ALI). We hypothesized that mechanical ventilation with low tidal (LT) volumes improves cerebral tissue oxygenation and metabolism after experimentally induced ALI., Methods: After inducing experimental ALI by surfactant depletion, we studied two conditions in 10 female pigs: 1) LT volume ventilation with 6 mL/kg body weight, and 2) high tidal (HT) volume ventilation with 12 mL/kg body weight. Variables of gas exchange, hemodynamic, continuous cerebral tissue oxygen tension (p(ti)O2), cerebral microdialysis, and systemic cytokines were analyzed. After induction of ALI, data were collected at 2, 4, and 8 h. The primary end point was the change in p(ti)O2. For group comparisons, a t-test was used. A value of <0.05 was considered to indicate statistical significance., Results: At baseline and after induction of ALI, no differences between groups were found in p(ti)O2; however, p(ti)O2 was significantly lower in the HT group after 4 and 8 h. PaO2 and PaCO2 showed no significant differences between the groups at all timepoints. Regarding cerebral microdialysis, a significantly higher level of extracellular lactate could be demonstrated after 2, 4, and 8 h in the HT group. The release of cytokines resulted in higher values for interleukin-6 and interleukin-8 in the HT group., Conclusion: Protective ventilation with LT yielded a significant improvement in cerebral tissue oxygenation and metabolism compared to HT ventilation in a porcine model of ALI. There was dissociation between arterial and cerebral tissue oxygenation. Cerebral oxygenation and metabolism might have possibly been impaired by a more distinctive inflammatory response in the HT group.

5-Endo-dig cycloisomerization of 1,4- and 1,2,4- mostly aryl-substituted but-3-yn-1-ones in the presence of a catalytic amount of zinc chloride etherate (10 mol %) in dichloromethane at room temperature gave 2,5-di- and 2,3,5-trisubstituted furans in high yields (85-97%). DSC studies confirmed that a solely thermal process does not take place. A relevant catalytic process, employing mu-oxo-tetranuclear zinc cluster Zn4(OCOCF3)6O, yielded bicyclic furopyrimidine nucleosides, when starting from acetyl-protected 5-alkynyl-2'-deoxyuridines (85-86%). Furopyrimidine was deprotected or simultaneously converted into pyrrolopyrimidine nucleoside. The time/concentration dependence for the reaction of 1-phenyl-4-(4-methylphenyl)butynone to 2-(4-methylphenyl)-5-phenylfuran displayed first-order kinetics with the rate dependent on catalyst concentration. The plot of ln k(obs) versus ln[ZnCl2] indicated first-order cycloisomerization, as referred to ZnCl2 concentration, using both NMR and UV-vis reaction monitoring. The crystal structure of propyl furopyrimidine nucleoside (orthorhombic, P2(1)2(1)2(1), a/b/c = 5.684(2)/6.682(2)/36.02(2) A, Z = 4) shows C2'- endo deoxyribose puckering, and the base is found in the anti position in crystalline form.

Background: In acute lung injury, ventilation avoiding tidal hyperinflation and tidal recruitment has been proposed to prevent ventilator-associated lung injury. Information about dynamic recruitment may be obtained from the characteristics of pressure-volume (PV) curves or the profile of pressure-time (Paw-t) curves., Methods: Six anesthetized pigs with lung lavage-induced acute lung injury were ventilated with lung-protective settings. We measured the effects of a standard recruitment maneuver on hysteresis area and ratio obtained from the PV curve and on the stress index obtained from the Paw-t curve and correlated this with aerated and nonaerated lung volumes as measured by multislice computed tomography., Results: Hysteresis area and ratio correlated with aerated lung volume (r = 0.886). The recruitment maneuver resulted in an increase in aerated (+12%) and a decrease (-18%) in nonaerated lung. Hysteresis area correlated with alveolar recruitment, represented by an increase in aerated lung (r = 0.886) and a decrease in nonaerated lung (r = -0.829) during tidal ventilation. The stress index was always >1 and indicated tidal hyperinflation only. Values did not change after the recruitment maneuver and did not correlate with any other lung volume., Conclusions: Parameters derived from the PV curve may help in characterizing the lung aeration of the lung and in indicating recruitment. In the presence of lung-protective ventilator settings, the stress index derived from the Paw-t curve was not able to indicate recruitment.

Unlabelled: In acute lung injury (ALI), controlled mechanical ventilation with decelerating inspiratory flow (.V(dec)) has been suggested to improve oxygenation when compared with constant flow (.V(con)) by improving the distribution of ventilation and perfusion (.V(A)/.Q). We performed the present study to test this hypothesis in an animal model of ALI. Furthermore, the effects of combined decelerating and constant flow (Vdot;(deco)) were evaluated. Thus, 18 pigs with experimental ALI were randomized to receive mechanical ventilation with either .V(con), .V(dec) or a fixed combination of both flow wave forms (.V(deco)) at the same tidal volume and positive end-expiratory pressure level for 6 h. Hemodynamics, gas exchange, and .V(A)/.Q distribution were determined. The results revealed an improvement of oxygenation resulting from a decrease of pulmonary shunt within each group (P < 0.05). However, blood flow to lung areas with a normal .V(A)/.Q distribution increased only during ventilation with .V(con) (P < 0.05). Accordingly, PaO(2) was higher with .V(con) than with .V(dec) and .V(deco) (P < 0.05). We conclude that contrary to the hypothesis, .V(con)provides a more favorable .V(A)/.Q distribution, and hence better oxygenation, when compared with .V(dec) and .V(deco) in this model of ALI., Implications: In acute lung injury, mechanical ventilation with decelerating flow has been suggested to improve ventilation-perfusion distribution when compared with constant flow. We tested this hypothesis in an animal model. Contrary to the hypothesis, we found a more favorable ventilation-perfusion distribution during constant flow when compared with decelerating flow.

5-Endo-dig electrophilic cyclization of 5-alkynyl-2'-deoxyuridines with N-iodosuccinimide or N-bromosuccinimide in acetone at room temperature gives 3-(2'-deoxy-beta-D-ribofuranosyl)-5-halo-2,3-dihydrofuro[2,3-d]pyrimidin-2-ones that usually precipitate from the reaction mixture (86-74%).

Unlabelled: It has been suggested that, in acute lung injury (ALI), spontaneous breathing activity may increase oxygenation because of an improvement of ventilation-perfusion distribution. Pressure support ventilation (PSV) is one of the assisted spontaneous breathing modes often used in critical care medicine. We sought to determine the prolonged effects of PSV on gas exchange in experimental ALI. We hypothesized that PSV may increase oxygenation because of an improvement in ventilation-perfusion distribution. Thus, ALI was induced in 20 pigs by using repetitive lung lavage. Thereafter, the animals were randomized to receive either PSV with a pressure level set to achieve a tidal volume >4 mL/kg and a respiratory rate <40 min(-1) (n = 10) or controlled mechanical ventilation (CMV) with a tidal volume of 10 mL/kg and a respiratory rate of 20 min(-1) (n = 10). Positive end-expiratory pressure was set at 10 cm H(2)O in both groups. Blood gas analyses and determination of ventilation-perfusion (.V(A)/.Q) distribution were performed at the onset of ALI and after 2, 4, 8, and 12 h. The main result was an improvement of oxygenation because of a decrease of pulmonary shunt and an increase of areas with normal .V(A)/.Q ratios during PSV (P < 0.005). However, during CMV, a more pronounced reduction of shunt was observed compared with PSV (P < 0.005). We conclude that, in this model of ALI, PSV improves gas exchange because of a reduction of .V(A)/.Q inequality. However, improvements in .V(A)/.Q distribution may be more effective with CMV than with PSV., Implications: Assisted spontaneous breathing may have beneficial effects on gas exchange in acute lung injury. We tested this hypothesis for pressure support ventilation in an animal model of acute lung injury. Our results demonstrate that pressure support does not necessarily provide better gas exchange than controlled mechanical ventilation.

Background: The mechanisms by which partial liquid ventilation (PLV) can improve gas exchange in acute lung injury are still unclear. Therefore, we examined the time- and dose-dependency of the improvements in arterial oxygen tension (PaO2) due to PLV in eight pigs with experimental lung injury, in order to discriminate increases due to oxygen dissolved in perfluorocarbon before its intrapulmonary instillation from a persistent diffusion of the respiratory gas through the liquid column., Results: Application of four sequential doses of perfluorocarbon resulted in a dose-dependent increase in PaO2. Comparison of measurements 5 and 30 min after instillation of each dose revealed a time-dependent decrease in PaO2 for doses that approximated the functional residual capacity of the animals., Conclusion: Although oxygen dissolved in perfluorocarbon at the onset of PLV can cause a short-term improvement in arterial oxygenation, diffusion of oxygen through the liquid may not be sufficient to maintain the initially observed increase in PaO2.