Comparison of three tracers for detecting lung epithelial injury in anesthetized sheep

1989 ◽  
Vol 66 (5) ◽  
pp. 2374-2383 ◽  
Author(s):  
B. T. Peterson ◽  
K. D. Dickerson ◽  
H. L. James ◽  
E. J. Miller ◽  
J. W. McLarty ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Lung Injury ◽  
Clearance Rate ◽  
Fluid Transport ◽  
Water Volume ◽  
Lung Edema ◽  
Lung Water ◽  
Lung Inflation ◽  
Epithelial Injury ◽  
Lung Epithelial

We compared the ability of three aerosolized tracers to discriminate among control, lung inflation with a positive end expired pressure of 10 cmH2O, lung vascular hypertension and edema without lung injury, and lung edema with lung injury due to intravenous oleic acid. The tracers were 99mTc-diethylenetriaminepentaacetate (99mTc-DTPA, mol wt 492), 99mTc-human serum albumin (99mTc-ALB, mol wt 69,000), and 99mTc-aggregated albumin (99mTc-AGG ALB, mol wt 383,000). 99mTc-DTPA clearance measurements were not able to discriminate lung injury from lung inflation. The 99mTc-AGG ALB clearance rate was unchanged by lung inflation and increased slightly with lung injury. The 99mTc-ALB clearance rate (0.06 +/- 0.02%/min) was unchanged by lung inflation (0.09 +/- 0.02%/min, P greater than 0.05) or 4 h of hypertension without injury (0.09 +/- 0.04%/min, P greater than 0.05). Deposition of 99mTc-ALB within 15 min of the administration of the oleic acid increased the clearance rate to 0.19 +/- 0.06%/min, which correlated well with the postmortem lung water volume (r = 0.92, P less than 0.01). This did not occur when there was a 60-min delay in the deposition of 99mTc-ALB. We conclude that 99mTc-ALB is the best indicator for studying the effects of lung epithelial injury on protein and fluid transport into and out of the air spaces of the lungs in a minimally invasive manner.

Lung water measurement by nuclear magnetic resonance: correlation with morphometry

1995 ◽  
Vol 79 (6) ◽  
pp. 2163-2168 ◽  
Author(s):  
A. G. Cutillo ◽  
K. C. Goodrich ◽  
K. Ganesan ◽  
S. Watanabe ◽  
D. C. Ailion ◽  
...  
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Oleic Acid ◽  
Magnetic Resonance ◽  
Lung Injury ◽  
Water Density ◽  
Inflation Pressure ◽  
Lung Water ◽  
Lung Inflation ◽  
Lung Water Content

Estimates of lung water content obtained from nuclear magnetic resonance (NMR) and morphometric and gravimetric measurements were compared in normal and experimentally injured rats. Average lung water density (rho H2O) was measured by an NMR technique in excised unperfused rat lungs (20 normal lungs and 12 lungs with oleic acid-induced edema) at 0 (full passive deflation) and 30 cmH2O lung inflation pressure and in vivo (4 normal rats and 8 rats with lung injury induced by oleic acid or rapid saline infusion). The rho H2O values were compared with morphometric measurements of lung tissue volume density (Vv) obtained from the same lungs fixed at corresponding liquid-instillation pressures. A close correlation was observed between rho H2O and Vv in normal and injured excised lungs [correlation coefficient (r) = 0.910, P < 0.01]. In vivo rho H2O was also closely correlated with Vv (r = 0.897, P < 0.01). The correlation coefficients between rho H2O and gravimetric lung water content (LWGr) were lower in the excised lung group (r = 0.663 and 0.692, respectively, for rho H2O at 0 and 30 cmH2O lung inflation pressure, P < 0.01) than in the in vivo study (r = 0.857, P < 0.01). Our results indicate that NMR techniques, which are noninvasive and nondestructive, provide reliable estimates of lung water density and that the influence of lung inflation on rho H2O is important (compared with the effect of lung water accumulation in lung injury) only in the presence of deliberately induced very large variations in the lung inflation level.

A positron emission tomographic comparison of diffuse and lobar oleic acid lung injury

1988 ◽  
Vol 64 (6) ◽  
pp. 2357-2365 ◽  
Author(s):  
D. P. Schuster ◽  
J. W. Haller ◽  
M. Velazquez
Keyword(s):  
Oleic Acid ◽  
Lung Injury ◽  
Dorsal Region ◽  
Lung Water ◽  
Positron Emission ◽  
Transcapillary Escape Rate ◽  
Severity Of Injury ◽  
Water Accumulation ◽  
The Right ◽  
Lung Lobes

We tested whether severity of injury measured from the pulmonary transcapillary escape rate for transferrin (PTCER), lung water accumulation, and changes in regional pulmonary blood flow (PBF) would be similar after oleic acid (OA) injection into either all lung lobes or directly into the pulmonary artery feeding the left caudal lobe (LCL) only. Measurements were made with positron emission tomography. After 0.015 ml/kg OA was injected into the LCL (Lobar, n = 5), lung water increased in the left dorsal region from 37 +/- 5 to 50 +/- 8 ml/100 ml lung (P less than 0.05), PTCER was 533 +/- 59 10(-4)/min, and regional PBF decreased 62%. No significant change occurred in the uninjured right dorsal lung where PTCER was 85 +/- 32. In the left ventral region PTCER was 357 +/- 60, PBF decreased only 31%, and the increase in lung water was less (25 +/- 3 to 30 +/- 6). In contrast after 0.08 ml/kg OA was injected via the right atrium (Diffuse, n = 6), PTCER (283 +/- 94) was lower in the left dorsal region of this group than in the corresponding region of the Lobar group (P less than 0.05). The increase in lung water, however, was the same, but no change occurred in PBF distribution. These results indicate important differences between the two methods of causing lung injury with OA. After injury lung water accumulates primarily in dependent portions of lung and is not always accompanied by a decrease in regional PBF. These decreases, when they occur, may instead indicate severe vascular injury.

Eicosanoid balance and perfusion redistribution of oleic acid-induced acute lung injury

1992 ◽  
Vol 73 (5) ◽  
pp. 2126-2134 ◽  
Author(s):  
A. H. Stephenson ◽  
A. J. Lonigro ◽  
S. W. Holmberg ◽  
D. P. Schuster
Keyword(s):  
Acute Lung Injury ◽  
Oleic Acid ◽  
Lung Injury ◽  
Water Concentration ◽  
Dependent Lung ◽  
Lung Water ◽  
Tissue Concentrations ◽  
Tissue Samples ◽  
Positron Emission ◽  
Regional Lung

We have proposed that endogenous prostacyclin opposes the vasoconstriction responsible for redistribution of regional pulmonary blood flow (rPBF) away from areas of increased regional lung water concentration (rLWC) in canine oleic acid- (OA) induced acute lung injury (D. P. Schuster and J. Haller. J. Appl. Physiol. 69: 353–361, 1990). To test this hypothesis, we related regional lung tissue concentrations of 6-ketoprostaglandin (PG) F1 alpha and thromboxane (Tx) B2 in tissue samples obtained 2.5 h after administration of OA (0.08 ml/kg iv) to rPBF and rLWC measured by positron emission tomography. After OA only (n = 16), rLWC increased in dependent lung regions. Some animals responded to increased rLWC by redistribution of rPBF away from the most edematous regions (OA-R, n = 6), whereas others did not (OA-NR, n = 10). In another six animals, meclofenamate was administered after OA (OA-meclo). After OA, tissue concentrations of 6-keto-PGF1 alpha were greater than TxB2 in all groups, but concentrations of 6-keto-PGF1 alpha were not different between OA-R and OA-NR animals. TxB2 was increased in the dependent regions of animals in both OA-R and OA-NR groups compared with controls (no OA, n = 4, P < 0.05). The tissue TxB2/6-keto-PGF1 alpha ratio was smaller in controls and OA-NR in which no perfusion redistribution occurred than in OA-R and OA-meclo in which it did occur. This TxB2/6-keto-PGF1 alpha ratio correlated significantly with the magnitude of perfusion redistribution.(ABSTRACT TRUNCATED AT 250 WORDS)

Assessment of temporal changes in pulmonary edema with NMR imaging

1989 ◽  
Vol 66 (3) ◽  
pp. 1197-1208 ◽  
Author(s):  
D. M. Phillips ◽  
P. S. Allen ◽  
S. F. Man
Keyword(s):  
Relaxation Time ◽  
Oleic Acid ◽  
Pulmonary Edema ◽  
Signal Intensity ◽  
Transverse Relaxation Time ◽  
Lung Edema ◽  
Lung Water ◽  
Transverse Relaxation ◽  
Acid Infusion ◽  
Potential Applicability

Nuclear magnetic resonance imaging (NMRI) parameters [longitudinal relaxation time (T1), transverse relaxation time (T2), and signal intensity] acquired at a magnetic field of 2.35 T were validated with a study of nine different phantom gel solutions. This technique was then applied to study 13 anesthetized supine cats, among which 10 had lung edema induced by oleic acid (0.075 ml/kg); the result was compared with postmortem analyses of lung water. Three animals (series A) were imaged until the edema was first visualized in NMRI, usually 15–20 min after oleic acid infusion. Another seven animals (series B) were imaged over 4–5 h. As lung water increased, so did the signal intensity. When edema first appeared, T1, T2, and the volume of the edematous region within the slice in the upper lobes showed no gravity-dependent differences; this was confirmed by postmortem measurements (series A) of lung water. With time, gravity-dependent regions displayed greater volumes of edematous regions and greater T1 values (P less than 0.01), suggesting a continued accumulation of lung water. In comparison, nondependent regions displayed constant volumes of edematous region and lesser T1 values (P less than 0.01), suggesting an increased protein concentration but no change in lung water. This study suggests the potential applicability of NMRI parameters in the assessment of pulmonary edema.

Effect of eicosanoid inhibition on the development of pulmonary edema after acute lung injury

1996 ◽  
Vol 80 (3) ◽  
pp. 915-923 ◽  
Author(s):  
D. P. Schuster ◽  
A. H. Stephenson ◽  
S. Holmberg ◽  
P. Sandiford
Keyword(s):  
Acute Lung Injury ◽  
Oleic Acid ◽  
Lung Injury ◽  
Pulmonary Edema ◽  
Experimental Models ◽  
Nuclear Medicine Imaging ◽  
Lung Water ◽  
Edema Formation ◽  
Cyclooxygenase Inhibition ◽  
Positron Emission

In experimental models of acute lung injury, cyclooxygenase inhibition improves oxygenation, presumably by causing a redistribution of blood flow away from edematous lung regions. This effect on perfusion pattern could also reduce alveolar edema formation. On the other hand, pulmonary pressures usually increase after cyclooxygenase inhibition, an effect that could exacerbate edema accumulation. Therefore we tested the following hypothesis: the total accumulation of pulmonary edema in dogs during a 24- to 28-h period of observation after acute lung injury caused by oleic acid will be less in a group of animals treated with meclofenamate (n = 6) or with the thromboxane-receptor blocker ONO-3708 (n = 5) than in a group of animals treated with oleic acid alone (placebo, n = 6). Lung water concentrations (LWC), the regional pattern of pulmonary perfusion, and protein permeability were measured with the nuclear medicine imaging technique of positron emission tomography. After 24-28 h, LWC was significantly less (P < 0.05) in the ONO-3708 group than in the meclofenamate group (a similar trend was seen compared with the placebo group, P = 0.12). After 24-28 h, pulmonary arterial pressures were highest in the meclofenamate group. Regardless of group, the only significant correlation with the change in LWC was with the integral of pulmonary pressures over the 24- to 28-h period. The data suggest that thromboxane inhibition will reduce edema accumulation in acute lung injury but that this effect depends on reducing as much as possible the simultaneous development of pulmonary hypertension from other causes.

Simultaneous measurement of lung clearance rates for Tc- and In-DTPA in normal and damaged lungs

1989 ◽  
Vol 66 (5) ◽  
pp. 2293-2297 ◽  
Author(s):  
H. O'Brodovich ◽  
G. Coates ◽  
J. Kay ◽  
D. Muysson
Keyword(s):  
Oleic Acid ◽  
Lung Injury ◽  
Computer Assisted ◽  
Clearance Rates ◽  
Lung Water ◽  
Imaging Characteristics ◽  
Widespread Availability ◽  
Lung Water Content ◽  
Arterial Po2

We investigated the relative clearance rates for 99mTc-labeled diethylenetriamine-pentaacetate (Tc-DTPA) and 113mIn-labeled DTPA (In-DTPA) when they were inhaled and deposited together within the lungs of same animal. Submicronic aerosols containing Tc-DTPA and In-DTPA were simultaneously generated by different nebulizers and collected within the same anesthetic bag. The combined aerosols were insufflated into piglets. Clearances for both compounds were measured simultaneously in normal lungs and when the lungs were damaged by intravenous oleic acid or by a presumed oxidant agent, intravenous or intratracheal phorbol myristate acetate (PMA). A medium-energy collimator and a computer-assisted gamma camera were used to calculate clearances. Correction was made for downscatter from the In photopeak into the Tc window. Marked lung injury occurred as evidenced by increases in lung water content and decreases in arterial PO2. The clearance of In-DTPA was slightly but significantly slower than for Tc-DTPA in each group of animals. The correlation (r = 0.93) between clearances for Tc-DTPA and In-DTPA was good, even though in vitro studies demonstrated that Tc-DTPA, but not In-DTPA, slowly dissociated at room and body temperatures. Oleic acid increased, but surprisingly, PMA had no effect on clearance rates for both In-DTPA and Tc-DTPA. We recommend continued use of Tc-DTPA for these measurements in view of its lower cost, requirement for only low-energy collimation, better imaging characteristics, and widespread availability. The overlap between control and injured lungs and the lack of increased clearance rates after PMA suggest this technique does not always detect acute lung injury.

scholarly journals Management of Phosgene-Induced Acute Lung Injury (ALI) by Personalized Protective PEEP-ECMO: What Can We Learn from Animal Bioassays?

2019 ◽  
pp. 1-9
Author(s):  
Chunli Yang ◽  
Chunli Yang ◽  
Yang Xiaogang ◽  
Zhaohui He
Keyword(s):  
Acute Lung Injury ◽  
Lung Injury ◽  
Dead Space ◽  
Extravascular Lung Water ◽  
Lung Mechanics ◽  
Lung Edema ◽  
Lung Water ◽  
Extravascular Lung Water Index ◽  
Water Index ◽  
Arterial Blood

Background: Phosgene (carbonyl dichloride) gas is an indispensable chemical intermediate used in numerous industrial processes. Acute lung injury (ALI) caused by accidental inhalation exposure to phosgene is characterized pulmonary edema being phenotypically manifested after an asymptomatic or more precisely phrased “clinical occult” period. Opposite to common clinical practice, protective treatment should be given preference to curative treatment. Treatment initiated already during the asymptomatic phase shortly after exposure requires prognostic endpoints preceding the lung edema for triage and re-triage. Treatment strategies need to be personalized and exposure-dose related. The objective of this post-hoc analysis of published data is to assess prognostic value of ventilation dead-space (Vd/Vt) and extravascular lung water index (EVLWI) to guide treatment by protective PEEP supplemented by venovenous (vv) ECMO. Methods: This paper aims to compare the overarching published framework from systematic toxicological research of phosgene in animal bioassays with the clinical evidence from four accidentally phosgenepoisoned workers admitted to hospital with life-threatening lung edema. Treatment focused on a combination of protective PEEP and ECMO to reverse phosgene-induced deterioration in lung mechanics by personalized mechanical ventilation. Endpoints selected for titration PEEP focused on endpoints indicative of decoupling cardiopulmonary and vascular functions. To better understand any cardiogenic and vascular disturbances, titration endpoints included calculated ventilation dead-space (Vd/Vt), measured extravascular lung water index (EVLWI), arterial blood gases and acid-base status, systemic vascular resistance index (SVRI), and cardiac index (CI). EVLWI and APACHE II criteria guided the course of treatment in adjusting plateau pressure (Pplat), positive end-expiratory pressure (PEEP), and driving pressure (ΔP). Results: Remarkable equivalence of human data and those from controlled inhalation studies with phosgene on rats and dogs was found. The endpoint of choice guiding PEEP ventilation and implementation of ECMO was EVLWI. This maker of lung edema precisely reflects the increased wet lung weights in animals. Conclusions: ECMO-supplemented PEEP not only mitigates hypoxemia at conditions of severe ARDS and it also provides a means to reduce driving and plateau pressures minimizing ventilatorassociated lung injury.

Effects of ventilation and pleural effusion on measurements of airway thermal volume and blood flow in dog lungs

1995 ◽  
Vol 79 (4) ◽  
pp. 1320-1329 ◽  
Author(s):  
A. Kano ◽  
K. Kambara ◽  
M. Arakawa ◽  
F. Ando ◽  
M. Ohno ◽  
...  
Keyword(s):  
Blood Flow ◽  
Pleural Effusion ◽  
Minute Ventilation ◽  
Water Volume ◽  
Lung Edema ◽  
Lung Water ◽  
Lung Weight ◽  
Thermodilution Cardiac Output ◽  
Wide Range ◽  
Alloxan Monohydrate

We studied the effects of ventilation and pleural effusion on measurements of airway thermal volume (ATV) and pulmonary blood flow (PBF) by using the airway gas thermometry method of V. B. Serikov, M. S. Rumm, K. Kambara, M. I. Bootomo, A. R. Osmack, and N. C. Staub (J. Appl. Physiol. 72: 944–953, 1992) in 39 anesthetized dogs with or without lung edema or pleural effusion. To examine the differential effects of increased-pressure and increased-permeability lung edema on accuracy and sensitivity of ATV and PBF, two models of lung edema were induced by intravenous infusion of a Dextran 70 solution and alloxan monohydrate, respectively. Dogs were hyperventilated for 3 min by using a wide range of minute ventilation (VE) to produce two steady-state conditions of airway temperature. Higher levels of VE increased an estimated amount of ATV. The ATV produced by hyperventilation at VE values of 559, 158, and 72 ml.min-1.kg-1 was consistent with the gravimetric total lung mass, the blood-free wet lung weight, and the extravascular lung water volume, respectively. The coefficient of lung thermal conductivity, a practical index of the rate of heat conduction through tissue from lung vessels, was related to the ratio of the decrease in expired air temperature to VE, and estimated PBF was consistent with the thermodilution cardiac output. Pleural effusion had little effect on measurements of ATV and PBF. However, ATV and PBF showed increased variation in dogs with dextran-induced lung edema.

Aerosolized Pseudomonas elastase and lung fluid balance in anesthetized sheep

1992 ◽  
Vol 72 (5) ◽  
pp. 1927-1933 ◽  
Author(s):  
B. T. Peterson ◽  
M. L. Collins ◽  
L. D. Gray ◽  
A. O. Azghani
Keyword(s):  
Left Atrial ◽  
Atrial Pressure ◽  
Left Atrial Pressure ◽  
Water Volume ◽  
Lung Epithelium ◽  
Lung Water ◽  
Lung Fluid ◽  
Lung Fluid Balance ◽  
Lung Epithelial ◽  
Lung Epithelial Permeability

The role of the lung epithelium in lung fluid balance was studied by ventilating anesthetized sheep with an aerosol of 20 mg of elastase from Pseudomonas aeruginosa (Ps. elastase) to increase lung epithelial permeability without affecting lung endothelial permeability or lung vascular pressures. Ps. elastase had no effect on the lung vascular pressures, the alveolar-arterial PO2 gradient (A-aPO2), the flow or protein concentration of the lung lymph, or the postmortem water volume of the lungs. The morphological alveolar flooding score in these sheep was 2.5 times the control level, but this was only marginally significant. Elevation of the left atrial pressure by 20 cmH2O alone increased the postmortem lung water volume but had no effect on A-aPO2, the alveolar flooding score, or the lung epithelial permeability assessed by the clearance of 99mTc-labeled human serum albumin. Addition of aerosolized Ps. elastase to these sheep had no effect on the total lung water volume, but it caused a redistribution of water into the air spaces, as evidenced by significant increases in the alveolar flooding score and A-aPO2 (P less than 0.01). Elevation of the left atrial pressure by 40 cmH2O without elastase caused the same response as elevation of the left atrial pressure by 20 cmH2O with elastase, except the higher pressure caused a greater increase in the total lung water volume. We conclude that alteration of the integrity of the lung epithelium with aerosolized Ps. elastase causes a redistribution of lung water into the alveoli without affecting the total lung water volume.(ABSTRACT TRUNCATED AT 250 WORDS)

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