Mechanical ventilation of isolated septic rat lungs: effects on surfactant and inflammatory cytokines

2001 ◽  
Vol 91 (2) ◽  
pp. 811-820 ◽  
Author(s):  
Tomoo Nakamura ◽  
Jaret Malloy ◽  
Lynda McCaig ◽  
Li-Juan Yao ◽  
Mariamma Joseph ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Tidal Volume ◽  
Morphological Changes ◽  
Cecal Ligation ◽  
Normal Lung ◽  
Positive End Expiratory Pressure ◽  
Surfactant System ◽  
Rat Lungs ◽  
Group 2 ◽  
Factor Α

The effects of mechanical ventilation (MV) on the surfactant system and cytokine secretion were studied in isolated septic rat lungs. At 23 h after sham surgery or induction of sepsis by cecal ligation and perforation (CLP), lungs were excised and randomized to one of three groups: 1) a nonventilated group, 2) a group subjected to 1 h of noninjurious MV (tidal volume = 10 ml/kg, positive end-expiratory pressure = 3 cmH2O), or 3) a group subjected to 1 h of injurious MV (tidal volume = 20 ml/kg, positive end-expiratory pressure = 0 cmH2O). Nonventilated sham and CLP lungs had similar compliance, normal lung morphology, surfactant, and cytokine concentrations. Injurious ventilation decreased compliance, altered surfactant, increased cytokines, and induced morphological changes compared with nonventilation in sham and CLP lungs. In these lungs, the surfactant system was similar in sham and CLP lungs; however, tumor necrosis factor-α and interleukin-6 levels were significantly higher in CLP lungs. We conclude that injurious ventilation altered surfactant independent of sepsis and that the CLP lungs were predisposed to the secretion of larger amounts of cytokines because of ventilation.

scholarly journals Management of Intraoperative Mechanical Ventilation to Prevent Postoperative Complications after General Anesthesia: A Narrative Review

2021 ◽  
Vol 10 (12) ◽  
pp. 2656
Author(s):  
Alberto Fogagnolo ◽  
Federica Montanaro ◽  
Lou’i Al-Husinat ◽  
Cecilia Turrini ◽  
Michela Rauseo ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Tidal Volume ◽  
Pulmonary Complications ◽  
Point Of View ◽  
Whole Body ◽  
Positive End Expiratory Pressure ◽  
Ventilation Strategies ◽  
Harmful Effects ◽  
Ventilation Induced Lung Injury ◽  
Different Levels

Mechanical ventilation (MV) is still necessary in many surgical procedures; nonetheless, intraoperative MV is not free from harmful effects. Protective ventilation strategies, which include the combination of low tidal volume and adequate positive end expiratory pressure (PEEP) levels, are usually adopted to minimize the ventilation-induced lung injury and to avoid post-operative pulmonary complications (PPCs). Even so, volutrauma and atelectrauma may co-exist at different levels of tidal volume and PEEP, and therefore, the physiological response to the MV settings should be monitored in each patient. A personalized perioperative approach is gaining relevance in the field of intraoperative MV; in particular, many efforts have been made to individualize PEEP, giving more emphasis on physiological and functional status to the whole body. In this review, we summarized the latest findings about the optimization of PEEP and intraoperative MV in different surgical settings. Starting from a physiological point of view, we described how to approach the individualized MV and monitor the effects of MV on lung function.

Effect of Tidal Volume and Positive End-Expiratory Pressure on Compliance during Mechanical Ventilation

CHEST Journal ◽  
1978 ◽  
Vol 73 (2) ◽  
pp. 158-162 ◽  
Author(s):  
Peter M. Suter ◽  
H. Barrie Fairley ◽  
Michael D. Isenberg
Keyword(s):  
Mechanical Ventilation ◽  
Tidal Volume ◽  
Positive End Expiratory Pressure

scholarly journals Inhibition of Poly(Adenosine Diphosphate–Ribose) Polymerase Attenuates Ventilator-induced Lung Injury

2008 ◽  
Vol 108 (2) ◽  
pp. 261-268 ◽  
Author(s):  
Rosanna Vaschetto ◽  
Jan W. Kuiper ◽  
Shyh Ren Chiang ◽  
Jack J. Haitsma ◽  
Jonathan W. Juco ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Lung Injury ◽  
Tidal Volume ◽  
Interleukin 6 ◽  
Inflammatory Responses ◽  
Adenosine Diphosphate ◽  
High Tidal Volume ◽  
Positive End Expiratory Pressure ◽  
Ventilator Induced Lung Injury ◽  
Pharmacologic Inhibition

Background Mechanical ventilation can induce organ injury associated with overwhelming inflammatory responses. Excessive activation of poly(adenosine diphosphate-ribose) polymerase enzyme after massive DNA damage may aggravate inflammatory responses. Therefore, the authors hypothesized that the pharmacologic inhibition of poly(adenosine diphosphate-ribose) polymerase by PJ-34 would attenuate ventilator-induced lung injury. Methods Anesthetized rats were subjected to intratracheal instillation of lipopolysaccharide at a dose of 6 mg/kg. The animals were then randomly assigned to receive mechanical ventilation at either low tidal volume (6 ml/kg) with 5 cm H2O positive end-expiratory pressure or high tidal volume (15 ml/kg) with zero positive end-expiratory pressure, in the presence and absence of intravenous administration of PJ-34. Results The high-tidal-volume ventilation resulted in an increase in poly(adenosine diphosphate-ribose) polymerase activity in the lung. The treatment with PJ-34 maintained a greater oxygenation and a lower airway plateau pressure than the vehicle control group. This was associated with a decreased level of interleukin 6, active plasminogen activator inhibitor 1 in the lung, attenuated leukocyte lung transmigration, and reduced pulmonary edema and apoptosis. The administration of PJ-34 also decreased the systemic levels of tumor necrosis factor alpha and interleukin 6, and attenuated the degree of apoptosis in the kidney. Conclusion The pharmacologic inhibition of poly(adenosine diphosphate-ribose) polymerase reduces ventilator-induced lung injury and protects kidney function.

scholarly journals Influence of positive end-expiratory pressure (PEEP) on histopathological and bacteriological aspects of pneumonia during low tidal volume mechanical ventilation

2004 ◽  
Vol 30 (12) ◽  
pp. 2263-2270 ◽  
Author(s):  
Pierre Emmanuel Charles ◽  
Laurent Martin ◽  
Manuel Etienne ◽  
Delphine Croisier ◽  
Lionel Piroth ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Tidal Volume ◽  
Positive End Expiratory Pressure ◽  
Low Tidal Volume

scholarly journals Split-ventilation for more than one patient, can it be done? Yes

2020 ◽  
Vol 1 (1) ◽  
pp. 1-7
Author(s):  
Ehab Daoud ◽  
◽  
Jewelyn Cabigan ◽  
Gary Kaneshiro ◽  
Kimiyo Yamasaki
Keyword(s):  
Mechanical Ventilation ◽  
Tidal Volume ◽  
Limited Resources ◽  
Experimental Setup ◽  
Cross Contamination ◽  
Positive End Expiratory Pressure ◽  
Careful Monitoring ◽  
Mechanical Ventilators ◽  
Number Of Patients ◽  
History Of

Background: The COVID-19 pandemic crisis has led to an international shortage of mechanical ventilation. Due to this shortfall, the surge of increasing number of patients to limited resources of mechanical ventilators has reinvigorated the interest in the concept of split ventilation or co-ventilation (ventilating more than one patient with the same ventilator). However, major medical societies have condemned the concept in a joint statement for multiple reasons. Materials and Methods: In this paper, we will describe the history of the concept, what is trending in the literature about it and along our modification to ventilate two patients with one ventilator. We will describe how to overcome such concerns regarding cross contamination, re-breathing, safely adjusting the settings for tidal volume and positive end expiratory pressure to each patient and how to safely monitor each patient. Main results: Our experimental setup shows that we can safely ventilate two patients using one ventilator. Conclusion: The concept of ventilating more than one patient with a single ventilator is feasible especially in crisis situations. However, we caution that it has to be done under careful monitoring with expertise in mechanical ventilation. More research and investment are crucially needed in this current pandemic crisis.

Responsiveness of and interactions between airways and tissue in guinea pigs during induced constriction

1993 ◽  
Vol 74 (6) ◽  
pp. 2848-2854 ◽  
Author(s):  
T. Nagase ◽  
T. Ito ◽  
M. Yanai ◽  
J. G. Martin ◽  
M. S. Ludwig
Keyword(s):  
Mechanical Ventilation ◽  
Smooth Muscle ◽  
Guinea Pig ◽  
Tidal Volume ◽  
Airway Smooth Muscle ◽  
Guinea Pigs ◽  
Positive End Expiratory Pressure ◽  
Ventilation Frequency ◽  
Low Concentrations ◽  
Before And After

Mechanical interdependence between airways and tissues can modify the magnitude of induced bronchoconstriction. We questioned whether the guinea pig, an animal with abundant airway smooth muscle, would differ from other species in the relative responsiveness of and interactions between airways and tissues. Therefore we induced constriction with aerosolized methacholine (MCh) and partitioned responses into airway and tissue components. We measured tracheal and alveolar pressures using alveolar capsules in open-chest guinea pigs (n = 9) during mechanical ventilation [frequency = 1 Hz, tidal volume = 6 ml/kg, positive end-expiratory pressure (PEEP) = 5 cmH2O] and calculated the resistance of lung (RL), tissue (Rti), and airway (Raw) before and after administration of aerosols of MCh in progressively doubling concentrations (0.063–16 mg/ml). In separate animals (n = 10), measurements were made at 3–13 cmH2O PEEP. After aerosols of saline and MCh (0.125-32 mg/ml), measurements were repeated at 3, 7, and 11 cmH2O PEEP. At submaximal levels of constriction, the airways and lung tissues demonstrated similar responsiveness. Increasing PEEP increased RL and Rti and decreased Raw under baseline conditions. At low concentrations of MCh, increasing PEEP increased RL but decreased RL at the highest concentration. Increases in PEEP significantly increased Rti at all concentrations of MCh but decreased Raw only at 8 mg/ml of MCh. These observations demonstrate that, in guinea pigs, during submaximal constriction, airways and tissues behave similarly; moreover, airway-parenchymal interdependence is important in determining the level of bronchoconstriction.

scholarly journals A Higher Tidal Volume May Be Used for Athletes according to Measured FVC

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Pavlos Myrianthefs ◽  
George Baltopoulos
Keyword(s):  
Mechanical Ventilation ◽  
Body Weight ◽  
Tidal Volume ◽  
Vital Capacity ◽  
Professional Athletes ◽  
Normal Lung ◽  
Predicted Body Weight ◽  
Lung Volumes ◽  
Males And Females ◽  
The Difference

We investigated whether professional athletes may require higher tidal volume (Tv) during mechanical ventilation hypothesizing that they have significantly higher “normal” lung volumes compared to what was predicted and to nonathletes. Measured and predicted spirometric values were recorded in both athletes and nonathletes using a Spirovit SP-1 spirometer (Schiller, Switzerland). NormalTv(6 mL/kg of predicted body weight) was calculated as a percentage of measured and predicted forced vital capacity (FVC) and the difference (δ) was used to calculate the additionalTvrequired using the equation: NewTv(TvN)=Tv+(Tv×δ). Professional athletes had significantly higher FVC compared to what was predicted (by 9% in females and 10% in males) and to nonathletes. They may also require aTvof 6.6 mL/kg for males and 6.5 mL/kg for females during mechanical ventilation. Nonathletes may require aTvof 5.8 ± 0.1 mL/kg and 6.3 ± 0.1 mL/kg for males and females, respectively. Our findings show that athletes may require additionalTvof 10% (0.6/6 mL/kg) for males and 8.3% (0.5/6 mL/kg) for females during general anesthesia and critical care which needs to be further investigated and tested.

Cardiorespiratory Effects of Positive End-expiratory Pressure during Progressive Tidal Volume Reduction (Permissive Hypercapnia) in Patients with Acute Respiratory Distress Syndrome

1995 ◽  
Vol 83 (4) ◽  
pp. 710-720. ◽  
Author(s):  
V. Marco Ranieri ◽  
Luciana Mascia ◽  
Tommaso Fiore ◽  
Francesco Bruno ◽  
Antonio Brienza ◽  
...  
Keyword(s):  
Mechanical Ventilation ◽  
Acute Respiratory Distress Syndrome ◽  
Gas Exchange ◽  
Respiratory Distress Syndrome ◽  
Respiratory Distress ◽  
Tidal Volume ◽  
Distress Syndrome ◽  
Alveolar Recruitment ◽  
Permissive Hypercapnia ◽  
Positive End Expiratory Pressure

Background In patients with acute respiratory distress syndrome (ARDS), the ventilatory approach is based on tidal volume (VT) of 10-15 ml/kg and positive end-expiratory pressure (PEEP). To avoid further pulmonary injury, decreasing VT and allowing PaCO2 to increase (permissive hypercapnia) has been suggested. Effects of 10 cmH2O of PEEP on respiratory mechanics, hemodynamics, and gas exchange were compared during mechanical ventilation with conventional (10-15 ml/kg) and low (5-8 ml/kg) VT. Methods Nine sedated and paralyzed patients were studied. VT was decreased gradually (50 ml every 20-30 min). Static volume-pressure (V-P) curves, hemodynamics, and gas exchange were measured. Results During mechanical ventilation with conventional VT, V-P curves on PEEP 0 (ZEEP) exhibited an upward convexity in six patients reflecting a progressive reduction in compliance with inflating volume, whereas PEEP resulted in a volume displacement along the flat part of this curve. After VT reduction, V-P curves in the same patients showed an upward concavity, reflecting progressive alveolar recruitment with inflating volume, and application of PEEP resulted in alveolar recruitment. The other three patients showed a V-P curve with an upward concavity; VT reduction increased this concavity, and application of PEEP induced greater alveolar recruitment than during conventional VT. With PEEP, cardiac index decreased by, respectively, 31% during conventional VT and 11% during low VT (P < 0.01); PaO2 increased by 32% and 71% (P < 0.01), respectively, whereas right-to-left venous admixture (Qs/Qt) decreased by 11% and 40%, respectively (P < 0.01). The greatest values of PaO2, static compliance, and oxygen delivery and the lowest values of Qs/Qt (best PEEP) were obtained during application of PEEP with low VT (P < 0.01). Conclusions Although PEEP induced alveolar hyperinflation in most patients during mechanical ventilation with conventional VT, at low VT, there appeared to be a significant alveolar collapse, and PEEP was able to expand these units, improving gas exchange and hemodynamics.

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