Intravenous tezosentan improves gas exchange and hemodynamics in acute lung injury secondary to meconium aspiration

2007 ◽  
Vol 34 (2) ◽  
pp. 368-376 ◽  
Author(s):  
Ralf Geiger ◽  
Axel Kleinsasser ◽  
Stephan Meier ◽  
Nikolaus Neu ◽  
Werner Pajk ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Gas Exchange ◽  
Lung Injury ◽  
Meconium Aspiration

scholarly journals Angiotensin-Converting Enzyme 2 Improves Arterial Hypoxemia in Meconium-Induced Acute Lung Injury in Piglets

2015 ◽  
Vol 2015 ◽  
pp. 1-7
Author(s):  
Benedikt Treml ◽  
Alexander Loeckinger ◽  
Axel Kleinsasser ◽  
Elisabeth Schoepf ◽  
Ralf Geiger ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Gas Exchange ◽  
Lung Injury ◽  
Angiotensin Converting Enzyme ◽  
Ang Ii ◽  
Converting Enzyme ◽  
Blood Gas ◽  
Meconium Aspiration ◽  
Angiotensin Converting Enzyme 2 ◽  
Partial Pressures

Objective. Meconium aspiration induces acute lung injury (ALI) in neonates born through meconium-stained amniotic fluid. As yet, there is no specific therapy for improving the outcome. Recently, angiotensin-converting enzyme 2 (ACE2), which inactivates angiotensin II (Ang II), has been shown to ameliorate murine ALI. Design. To evaluate the therapeutic potential of this substance, we studied ACE2 in a piglet model of ALI induced by meconium aspiration. Subjects. Twelve anesthetized piglets were subjected in an animal research laboratory. ALI was induced by tracheal meconium instillation. Thereafter, six animals were randomly assigned to the ACE2 group, while another 6 served as control. Measurements. Systemic, pulmonary hemodynamic, and blood gas exchange parameters and Ang II levels were examined before ALI induction and at various time points after administering ACE2 or saline. In addition, ventilation-perfusion distribution of the lung was assessed by the multiple inert gas elimination technique (MIGET). Main Results. Animals treated with ACE2 maintained significantly higher arterial partial pressures of oxygen (Pao2) and lower arterial partial pressures of carbon dioxide (Paco2), respectively. Furthermore, Ang II, which was substantially increased, returned to basal values. Conclusion. In summary, ACE2 improves blood gas exchange in meconium-induced ALI in piglets.

Colloidal gold particles as a new in vivo marker of early acute lung injury

2004 ◽  
Vol 287 (4) ◽  
pp. L867-L878 ◽  
Author(s):  
Kai Heckel ◽  
Rainer Kiefmann ◽  
Martina Dörger ◽  
Mechthild Stoeckelhuber ◽  
Alwin E. Goetz
Keyword(s):  
Electron Microscopy ◽  
Acute Lung Injury ◽  
Gas Exchange ◽  
Lung Injury ◽  
Colloidal Gold ◽  
Microvascular Permeability ◽  
Arterial Oxygen ◽  
Control Group ◽  
Gold Particles

Permeability of the endothelial barrier to large molecules plays a pivotal role in the manifestation of early acute lung injury. We present a novel and sensitive technique that brings microanatomical visualization and quantification of microvascular permeability in line. White New Zealand rabbits were anesthetized and ventilated mechanically. Rabbit serum albumin (RSA) was labeled with colloidal gold particles. We quantified macromolecular leakage of gold-labeled RSA and thickening of the gas exchange distance by electron microscopy, taking into account morphology of microvessels. The control group receiving a saline solution represented a normal gas exchange barrier without extravasation of gold-labeled albumin. Infusion of lipopolysaccharide (LPS) resulted in a significant displacement of gold-labeled albumin into pulmonary cells, the lung interstitium, and even the alveolar space. Correspondingly, intravital fluorescence microscopy and digital image analysis indicated thickening of width of alveolar septa. The findings were accompanied by a deterioration of alveolo-arterial oxygen difference, whereas wet/dry ratio and albumin concentration in the bronchoalveolar lavage fluid failed to detect that early stage of pulmonary edema. Inhibition of the nuclear enzyme poly(ADP-ribose) synthetase by 3-aminobenzamide prevented LPS-induced microvascular injury. To summarize: colloidal gold particles visualized by standard electron microscopy are a new and very sensitive in vivo marker of microvascular permeability in early acute lung injury. This technique enabling detailed microanatomical and quantitative pathophysiological characterization of edema formation can form the basis for evaluating novel treatment strategies against acute lung injury.

Short-term Cardiorespiratory Effects of Proportional Assist and Pressure-support Ventilation in Patients with Acute Lung Injury/Acute Respiratory Distress Syndrome

2006 ◽  
Vol 105 (4) ◽  
pp. 703-708 ◽  
Author(s):  
Eumorfia Kondili ◽  
Nectaria Xirouchaki ◽  
Katerina Vaporidi ◽  
Maria Klimathianaki ◽  
Dimitris Georgopoulos
Keyword(s):  
Acute Respiratory Distress Syndrome ◽  
Acute Lung Injury ◽  
Gas Exchange ◽  
Lung Injury ◽  
Respiratory Distress Syndrome ◽  
Pressure Support Ventilation ◽  
Pressure Support ◽  
Distress Syndrome ◽  
Short Term ◽  
Support Ventilation

Background Recent data indicate that assisted modes of mechanical ventilation improve pulmonary gas exchange in patients with acute lung injury (ALI)/acute respiratory distress syndrome (ARDS). Proportional assist ventilation (PAV) is a new mode of support that amplifies the ventilatory output of the patient effort and improves patient-ventilator synchrony. It is not known whether this mode may be used in patients with ALI/ARDS. The aim of this study was to compare the effects of PAV and pressure-support ventilation on breathing pattern, hemodynamics, and gas exchange in a homogenous group of patients with ALI/ARDS due to sepsis. Methods Twelve mechanically ventilated patients with ALI/ARDS (mean ratio of partial pressure of arterial oxygen to fractional concentration of oxygen 190 +/- 49 mmHg) were prospectively studied. Patients received pressure-support ventilation and PAV in random order for 30 min while maintaining mean airway pressure constant. With both modes, the level of applied positive end-expiratory pressure (7.1 +/- 2.1 cm H2O) was kept unchanged throughout. At the end of each study period, cardiorespiratory data were obtained, and dead space to tidal volume ratio was measured. Results With both modes, none of the patients exhibited clinical signs of distress. With PAV, breathing frequency and cardiac index were slightly but significantly higher than the corresponding values with pressure-support ventilation (24.5 +/- 6.9 vs. 21.4 +/- 6.9 breaths/min and 4.4 +/- 1.6 vs. 4.1 +/- 1.3 l . min . m, respectively). None of the other parameters differ significantly between modes. Conclusions In patients with ALI/ARDS due to sepsis, PAV and pressure-support ventilation both have clinically comparable short-term effects on gas exchange and hemodynamics.

scholarly journals Derecruitment Test and Surfactant Therapy in Patients with Acute Lung Injury

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Alexey A. Smetkin ◽  
Vsevolod V. Kuzkov ◽  
Konstantin M. Gaidukov ◽  
Lars J. Bjertnaes ◽  
Mikhail Y. Kirov
Keyword(s):  
Acute Lung Injury ◽  
Gas Exchange ◽  
Lung Injury ◽  
Predictive Value ◽  
Conventional Therapy ◽  
Therapy Group ◽  
Lung Mechanics ◽  
Lung Water ◽  
Mechanically Ventilated ◽  
Water Index

Introduction. A recruitment maneuver (RM) may improve gas exchange in acute lung injury (ALI). The aim of our study was to assess the predictive value of a derecruitment test in relation to RM and to evaluate the efficacy of RM combined with surfactant instillation in patients with ALI.Materials and Methods. Thirteen adult mechanically ventilated patients with ALI were enrolled into a prospective pilot study. The patients received protective ventilation and underwent RM followed by a derecruitment test. After a repeat RM, bovine surfactant (surfactant group,n=6) or vehicle only (conventional therapy group,n=7) was instilled endobronchially. We registered respiratory and hemodynamic parameters, including extravascular lung water index (EVLWI).Results. The derecruitment test decreased the oxygenation in 62% of the patients. We found no significant correlation between the responses to the RM and to the derecruitment tests. The baseline EVLWI correlated with changes in SpO2following the derecruitment test. The surfactant did not affect gas exchange and lung mechanics but increased EVLWI at 24 and 32 hrs.Conclusions. Our study demonstrated no predictive value of the derecruitment test regarding the effects of RM. Surfactant instillation was not superior to conventional therapy and might even promote pulmonary edema in ALI.

Gas Exchange and Histopathology in a 2 Hit Murine Model of Acute Lung Injury (ALI).

2009 ◽  
Author(s):  
F Fichtner ◽  
MT Voelker ◽  
A Hoelman ◽  
T Busch ◽  
M Kasper ◽  
...  
Keyword(s):  
Acute Lung Injury ◽  
Gas Exchange ◽  
Lung Injury ◽  
Murine Model

Effect of inhaled nitric oxide on pulmonary hemodynamics after acute lung injury in dogs

1994 ◽  
Vol 76 (3) ◽  
pp. 1356-1362 ◽  
Author(s):  
J. A. Romand ◽  
M. R. Pinsky ◽  
L. Firestone ◽  
H. A. Zar ◽  
J. R. Lancaster
Keyword(s):  
Nitric Oxide ◽  
Acute Lung Injury ◽  
Gas Exchange ◽  
Lung Injury ◽  
Dead Space ◽  
Left Ventricular ◽  
Right Atrial ◽  
Adrenergic Blockade ◽  
Pulmonary Hemodynamics ◽  
Beta Adrenergic

Increased pulmonary vascular resistance (PVR) and mismatch in ventilation-to-perfusion ratio characterize acute lung injury (ALI). Pulmonary arterial pressure (Ppa) decreases when nitric oxide (NO) is inhaled during hypoxic pulmonary vasoconstriction (HPV); thus NO inhalation may reduce PVR and improve gas exchange in ALI. We studied the hemodynamic and gas exchange effects of NO inhalation during HPV and then ALI in eight anesthetized open-chest mechanically ventilated dogs. Right atrial pressure, Ppa, and left ventricular and arterial pressures were measured, and cardiac output was estimated by an aortic flow probe. Shunt and dead space were also estimated. The effect of 5-min exposures to 0, 17, 28, 47, and 0 ppm inhaled NO was recorded during hyperoxia, hypoxia, and oleic acid-induced ALI. During ALI, partial beta-adrenergic blockade (propranolol, 0.15 mg/kg i.v.) was induced and 74 ppm NO was inhaled. Nitrosylhemoglobin (NO-Hb) and methemoglobin (MetHb) levels were measured. During hyperoxia, NO inhalation had no measurable effects. Hypoxia increased Ppa (from 19.8 +/- 6.1 to 28.3 +/- 8.7 mmHg, P < 0.01) and calculated PVR (from 437 +/- 139 to 720 +/- 264 dyn.s.cm-5, P < 0.01), both of which decreased with 17 ppm NO. ALI decreased arterial PO2 and increased airway pressure, shunt, and dead space ventilation. Ppa (19.8 +/- 6.1 vs. 23.4 +/- 7.7 mmHg) and PVR (437 +/- 139 vs. 695 +/- 359 dyn.s.cm-5, P < 0.05) were greater during ALI than during hyperoxia. No inhalation had no measureable effect during ALI before or after beta-adrenergic blockade. MetHb remained low, and NO-Hb was unmeasurable. Bolus infusion of nitroglycerin (15 micrograms) induced an immediate decrease in Ppa and PVR during ALI.(ABSTRACT TRUNCATED AT 250 WORDS)

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