BACKGROUND: Partial liquid ventilation (PLV) and prone positioning can improve the arterial oxygenation (PaO2) in acute lung injury (ALI). We evaluated the effect of prolonged prone positioning during partial liquid ventilation (PLV) in a canine model of acute lung injury. METHODS: Six mongrel dogs (weighing 17.4 +/- 0.7 kg each) were anesthetized, intubated and mechanically ventilated. After 1 hour of baseline stabilization, the dogs' lungs were instilled with 40 mL/kg perfluorocarbon (PFC). PLV was first performed in the supine position for 1 hour (S1), then in the prone position for 3 hours with hourly measurements (P1, P2, P3), and finally, PLV was performed with the animal turned back to the supine position for 1 hour (S2). RESULTS: After instillation of the PFC, the PaO2 significantly increased from 99.2 +/- 32.6 mmHg at baseline to 198.1 +/- 59.2 mmHg at S1 (p=0.001). When the dogs were turned to the prone position, the PaO2 further increased to 288.3 +/- 80.9 mmHg at P1 (p=0.008 vs. S1) : this increase was maintained for 3 hours, but the PaO2 decreased to 129.4 +/- 62.5 mmHg at S2 (p< 0.001 vs. P3). Similar changes were seen in the shunt fraction. There were no significant differences for the systemic hemodynamic parameters between the prone and supine positions. CONCLUSION: Prolonged prone positioning during PLV in an animal model of ALI appears to improve oxygenation without any hemodynamic compromise.
Animals ; Dogs ; Liquid Ventilation/*methods ; Models, Animal ; Prone Position/*physiology ; Pulmonary Gas Exchange/*physiology ; Research Support, Non-U.S. Gov't ; Respiratory Distress Syndrome, Adult/physiopathology/*therapy

BACKGROUNDPediatric patients are susceptible to lung injury. Acute lung injury in children often results in high mortality. Partial liquid ventilation (PLV) has been shown to markedly improve oxygenation and reduce histologic evidence of injury in a number of lung injury models. This study was designed to examine the hypothesis that PLV would attenuate the production of local and systemic tumor necrosis factor (TNF)-α in an immature piglet model of acute lung injury induced by oleic acid (OA).

METHODSTwelve Chinese immature piglets were induced acute lung injury by OA. The animals were randomly assigned to two groups of six animals, (1) conventional mechanical ventilation (MV) group and (2) PLV with 10 ml/kg FC-77 group.

RESULTSCompared with MV group, the PLV group had better cardiopulmonary variables (P < 0.05). These variables included heart rate, mean blood pressure, blood pH, partial pressure of arterial oxygen (PaO2), PaO2/inspired O2 fraction (FiO2) and partial pressure of arterial carbon dioxide (PaCO2). PLV reduced TNF-α levels both in plasma and tissue compared with MV group (P < 0.05).

CONCLUSIONPLV provides protective effects against TNF-α response in OA-induced acute lung injury in immature piglets.

Acute Lung Injury ; chemically induced ; metabolism ; therapy ; Animals ; Animals, Newborn ; Liquid Ventilation ; methods ; Oleic Acid ; toxicity ; Swine ; Tumor Necrosis Factor-alpha ; blood ; metabolism

OBJECTIVETo investigate the influence of high frequency partial liquid ventilation (HFJV) on the cardiopulmonary function in dogs with inhalation injury.

METHODSSixteen mongrel dogs inflicted by hot steam inhalation were subjected to severe inhalation injury and were randomly divided into control (C) and treatment (T) groups. The dogs in both groups were all given HFJV. In addition, the dogs in T group were simultaneously supplied with perfluorocarbon liquid (3 ml/kg) into the lungs slowly via tracheal intubation for liquid ventilation. The blood gas analysis, pulmonary compliance, airway resistance and hemodynamic parameters were determined at 30, 60 and 90 minutes after ventilation.

RESULTSThe PaO(2) in T group increased progressively, which was significantly higher than the post-injury value at all time points (P < 0.05). While the PaO(2) in C group exhibited no difference to the post-injury value at all time points. The PaCO(2) in T group increased obviously and was higher than the post-injury value at 60 and 90 post-ventilation minutes (P < 0.05). Furthermore, the PaO(2) in all the time points in T group was a little higher than that in C group (P > 0.05) and PaCO(2) in T group was much higher than that in C group at 90 min after ventilation (P < 0.05). But there was no difference between the two groups in terms of dynamic/static pulmonary compliance and airway resistance as well as the hemodynamics.

CONCLUSIONCompared with simple HFJV, high frequency partial liquid ventilation seemed to be beneficial to the oxygenation after inhalation injury and to be no influence on the hemodynamics.

Airway Resistance ; Animals ; Blood Gas Analysis ; Burns, Inhalation ; physiopathology ; therapy ; Dogs ; Female ; High-Frequency Jet Ventilation ; Liquid Ventilation ; Lung Compliance ; Male ; Pulmonary Circulation ; Pulmonary Gas Exchange ; Respiration, Artificial ; methods ; Respiratory Function Tests ; Time Factors

BACKGROUNDPediatric patients are susceptible to lung injury that does not respond to traditional therapies. Total liquid ventilation has been developed as an alternative ventilatory strategy for severe lung injury. The aim of this study is to investigate the effect of total liquid ventilation on oleic acid (OA)-induced lung injury in piglets.

METHODSTwelve Chinese immature piglets were induced acute lung injury by OA. Twelve piglets were randomly treated with conventional gas ventilation (control group) or total liquid ventilation (study group) for 240 minutes. Samples for blood gas analysis were collected before, and at 60-minute intervals after OA-induced lung injury. The degree of lung injury was quantified by histologic examination. The inflammatory cells and the levels of IL-1β, IL-6, IL-10 and TNF-α in plasma, tissue and bronchoalveolar lavage were analyzed.

RESULTSNeutrophil and macrophage counts in bronchoalveolar lavage were significantly decreased in the study group (P < 0.05). The total lung injury score was also reduced in the study group (P < 0.05). The concentrations of IL-1β, IL-6, IL-10 and TNF-α in plasma, tissue and bronchoalveolar lavage were significantly reduced in the study group (P < 0.05).

CONCLUSIONSTotal liquid ventilation reduces biochemical and histologic OA-induced lung injury in piglets.

Acute Lung Injury ; chemically induced ; metabolism ; therapy ; Animals ; Interleukin-10 ; metabolism ; Interleukin-1beta ; metabolism ; Interleukin-6 ; metabolism ; Liquid Ventilation ; methods ; Oleic Acid ; toxicity ; Swine ; Tumor Necrosis Factor-alpha ; metabolism

BACKGROUNDPediatric patients are susceptible to lung injury. Acute lung injury (ALI) in children often results in a high mortality. Partial liquid ventilation (PLV) has been shown to markedly improve oxygenation and reduce histologic evidence of injury in a number of lung injury models. This study aimed to examine the hypothesis that PLV would attenuate the production of local and systemic cytokines in an immature piglet model of ALI induced by oleic acid (OA).

METHODSTwelve Chinese immature piglets were induced to develop ALI by oleic acid. The animals were randomly assigned to two groups (n = 6): (1) conventional mechanical ventilation (MV) group and (2) PLV with FC-77 (10 ml/kg) group.

RESULTSCompared with MV group, PLV group got better cardiopulmonary variables (P < 0.05). These variables included heart rate, mean blood pressure, blood pH, partial pressure of arterial oxygen (PaO2), PaO2/FiO2 and partial pressure of arterial carbon dioxide (PaCO2). Partial liquid ventilation reduced IL-1beta, IL-6, IL-10 and TNF-alpha both in plasma and tissue concentrations compared with MV group (P < 0.05).

CONCLUSIONSPartial liquid ventilation provides protective effects against inflammatory responses in the lungs of oleic acid-induced immature piglets.

Animals ; Fluorocarbons ; therapeutic use ; Hemodynamics ; drug effects ; Inflammation ; chemically induced ; therapy ; Interleukin-10 ; metabolism ; Interleukin-1beta ; metabolism ; Interleukin-6 ; metabolism ; Liquid Ventilation ; methods ; Lung Injury ; immunology ; therapy ; Oleic Acid ; toxicity ; Random Allocation ; Respiration, Artificial ; Swine ; Tumor Necrosis Factor-alpha ; metabolism