Dimensional Analysis and Optimization of IsoTruss Structures with Outer Longitudinal Members in Uniaxial Compression.

This study analyzes the buckling behavior of 8-node IsoTruss structures with outer longitudinal members. IsoTruss structures are light-weight composite lattice columns with diverse structural applications, including the potential to replace rebar cages in reinforced concrete. In the current work, finite element analyses are used to predict the critical buckling loads of structures with various dimensions.

[Carbon monoxide and cyanide gas poisoning in fires].

Acute poisoning caused by inhalation of carbon monoxide and other toxic substances is the primary cause of death in fires and may occur without signs of external injury. Life-threatening symptoms may arise immediately, as in cyanide poisoning, or over a longer period, as in carbon monoxide poisoning. Severe inhalation injury may also occur independently of systemic poisoning and should always be suspected in patients with soot on their face and in the respiratory tract, or hoarseness and wheezing.

Bronchial wheezing predicts inflammation and respiratory failure in fire smoke victims.

Background: Acute fire smoke inhalation injury involves inflammatory mediators whose roles are poorly understood. We carried out a prospective observational study of fire smoke victims to identify clinical and biochemical markers that may predict pulmonary dysfunction and investigated possible correlations between dysfunction and cytokines in bronchoalveolar lavage (BAL) fluid and blood.

Methods: Forty patients with respiratory and/or neurological symptoms following acute fire smoke inhalation had pulmonary function tests and blood gas analyses performed on admission, at discharge, and after 3 months.

Manual ventilation and open suction procedures contribute to negative pressures in a mechanical lung model.

Introduction: Removal of pulmonary secretions in mechanically ventilated patients usually requires suction with closed catheter systems or flexible bronchoscopes. Manual ventilation is occasionally performed during such procedures if clinicians suspect inadequate ventilation. Suctioning can also be performed with the ventilator entirely disconnected from the endotracheal tube (ETT).

Can ventilator settings reduce the negative effects of endotracheal suctioning? Investigations in a mechanical lung model.

Background: The insertion of suction devices through endotracheal tubes (ETTs) increases airway resistance and the subsequent suctioning may reduce airway pressures and facilitate atelectasis. The aim of this study was to investigate how airway pressures and tidal volumes change when different combinations of suction equipment and ETT sizes are used, and to what extent unfavorable effects can be ameliorated by choice of ventilator settings.

Methods: A mechanical ventilator was connected to a lung model by ETTs of 9 mm, 8 mm or 7 mm internal diameter (ID) with a pressure transducer inserted distal to the ETT.

Intramedullary nailing of femoral shaft fractures in polytraumatized patients. a longitudinal, prospective and observational study of the procedure-related impact on cardiopulmonary- and inflammatory responses.

Background: Early intramedullary nailing (IMN) of long bone fractures in severely injured patients has been evaluated as beneficial, but has also been associated with increased inflammation, multi organ failure (MOF) and morbidity. This study was initiated to evaluate the impact of primary femoral IMN on coagulation-, fibrinolysis-, inflammatory- and cardiopulmonary responses in polytraumatized patients.

Methods: Twelve adult polytraumatized patients with femoral shaft fractures were included.

Intrabronchial airway pressures in intubated patients during bronchoscopy under volume controlled and pressure controlled ventilation.

Bronchoscope insertion through an endotracheal tube increases airflow resistance. Constant tidal volume (T(v)) ventilation can be maintained by augmenting the inspiratory pressure, but increased outflow resistance cannot be compensated for. Air trapping distal to the tube may lead to higher airway pressures in volume controlled (VC) mode and reduced T(v) in pressure controlled (PC) mode.

The acidosis-induced right shift of the HbO₂ dissociation curve is maintained during erythrocyte storage.

Background And Objectives: In fresh blood, tissue hypoxia increases microcirculatory acidosis, which enhances erythrocyte O(2) unloading and increases the amount of available O(2). Storage of erythrocytes increases the HbO(2) affinity and reduces O(2) unloading. We examined the development of the affinity change during a period of 5 weeks of storage by present blood bank standards, and investigated to what extent acidosis offsets the affinity change.

Intravasation of bone marrow content. Can its magnitude and effects be modulated by low pressure reaming in a porcine model?

Introduction: Intramedullary orthopaedic procedures may increase the intramedullary pressure (IMP) and thereby cause intravasation of bone marrow contents. In recent studies by the authors the reamer-irrigator-aspirator (RIA) has been demonstrated to reduce IMP and coagulation-, fibrinolysis- and cytokine responses, but did not prove any significant difference in cardiopulmonary function parameters or numbers of emboli when compared to a traditional reaming (TR) system. The correlations between IMP increase, regardless type of reamer, and inflammatory- and coagulation responses, pulmonary embolization, and cardiopulmonary alterations have, however, not previously been analyzed in this material.

Coagulation, fibrinolysis and cytokine responses to intramedullary nailing of the femur: an experimental study in pigs comparing traditional reaming and reaming with a one-step reamer-irrigator-aspirator system.

Introduction: Operations in trauma patients represent a second insult and the extent of the surgical procedures influences the magnitude of the inflammatory response. Our hypothesis was that a reamer-irrigator-aspirator (RIA) system would cause a lesser inflammatory response than traditional reaming (TR).

Materials And Methods: Coagulation, fibrinolysis and cytokine responses were studied in Norwegian landrace pigs during and after intramedullary nailing (IMN) with two different reaming systems using ELISA and chromogenic peptide substrate assays.

Cardiopulmonary response to reamed intramedullary nailing of the femur comparing traditional reaming with a one-step reamer-irrigator-aspirator reaming system: an experimental study in pigs.

Background: Intramedullary reaming and nailing increases intramedullary pressure. This may cause intravasation of bone marrow contents, leading to bone marrow embolization and altered cardiopulmonary function. Possible beneficial effects of attenuation of the intramedullary pressure increase by the use of a reamer-irrigator-aspirator (RIA) system were studied with the hypothesis that the RIA technique would cause lower numbers of pulmonary embolisms (PEs) and lesser cardiopulmonary affection than traditional reaming (TR).

[Acute respiratory failure concomitant with serious disease or injury].

Background: Acute respiratory failure has an annual incidence of 20-75/100,000 and is the most common reason for admittance to an intensive care unit. A common cause is acute inflammatory changes in lung tissue. The article reviews clinical, etiological, pathophysiological and therapeutic aspects of acute respiratory failure, with an emphasis on failure secondary to proinflammatory processes.

Blood leucocyte cytokine production after LPS stimulation at different concentrations of glucose and/or insulin.

Background: Previous studies have indicated that alterations in blood glucose and/or insulin levels modify the inflammatory response. The purpose of this study was to elucidate whether increased levels of glucose and/or insulin influence the activation pattern of blood leucocytes and their production of cytokines in vitro.

Methods: Venous blood was obtained from eight healthy male volunteers after an overnight fast.

Grave acidosis after severe anaphylactic bronchospasm: friend or foe?

In a 20-year-old woman with known asthma, anaphylactic bronchospasm induced a grave combined respiratory and metabolic acidosis (pH(a) 6.66) with marked hypoxaemia (S(a)O(2) 45%). The beneficial effects of the rightward shift of the oxyhaemoglobin dissociation curve on tissue O(2) unloading at such pH was more than offset by the negative effect on S(a)O(2) at the reduced P(a)O(2) (7.

Inhalation of nitric oxide inhibits ADP-induced platelet aggregation and alpha-granule release.

To gather further information about the effects on blood platelet activation of in vivo exposure to nitric oxide (NO), platelet reactivity was studied in blood from healthy, non-smoking male volunteers before and after 30 min inhalation of 40 ppm NO. Whole blood was stimulated in vitro with adenosine diphosphate or thrombin receptor activation peptide (TRAP-6). In an ex vivo perfusion model, non-anticoagulated blood was exposed to immobilised collagen at arterial blood flow conditions (2600 s(-1)).

Acute myocardial infarction and thyrotoxic storm--a difficult and dangerous combination.

We describe an unusual case of acute myocardial infarction (AMI) and cardiogenic shock in a 25-year-old woman. After coronary revascularization, a thyrotoxic storm developed and the patient's cardiac failure changed into a hyperdynamic circulation without obvious changes in the patient's vital signs. This report will focus on three issues: (1) the benefit of advanced hemodynamic monitoring in circulatory unstable patients, (2) the confounding effects of untreated hyperthyroidism on the circulation, and (3) previous cancer treatment as a cause of AMI in young persons.

Effects of short-term nitrogen monoxide inhalation on leukocyte adhesion molecules, generation of reactive oxygen species, and cytokine release in human blood.

Increased nitrogen monoxide (NO) concentrations change leukocyte function under a multitude of experimental conditions. NO inhalation is an experimental treatment for lung failure and exposes leukocytes to increased NO concentrations during passage through the lungs. To investigate whether short-term NO inhalation induces lasting changes in the function of circulating human leukocytes, venous blood samples were drawn from eight healthy male volunteers before and at the end of a 35-min period of breathing 40 ppm NO in 30% O(2).

Effect of extreme metabolic acidosis on oxygen delivery capacity of the blood--an in vitro investigation of changes in the oxyhemoglobin dissociation curve in blood with pH values of approximately 6.30.

Objectives: To determine the oxyhemoglobin dissociation curve in blood with pH of approximately 6.3 due to metabolic and superimposed respiratory acidosis, and to evaluate the oxygen delivery capacity of the blood under these circumstances.

Design: In vitro study.

[Upper airway obstruction].

The general symptoms of upper airway obstruction are described, as well as the specific symptoms expected to be found in various conditions that cause such obstruction. An algorithm, intended primarily for general practitioners and other physicians who seldom confront such problems, describes the procedures for establishing an unobstructed airway in different situations. It also outlines the interventions necessary to ensure adequate oxygenation and ventilation when such procedures fail.

Effects of high dose E. coli lipopolysaccharide on rabbit lung function, and of subsequent addition of chemotactic granulocyte activators to their isolated, blood-perfused lungs.

E. coli LPS was infused (1 microgram/kg to 5 mg/kg over 30 min) to spontaneously breathing rabbits, and their arterial blood pressure (ABP), blood leukocyte count and blood gases were observed for 2.5-3.