Jörg U. Bleyl

Changes in pulmonary function and oxygenation during application of perfluorocarbon vapor in healthy and oleic acid-injured animals.

ObjectivesTo investigate the changes in pulmonary function and gas exchange during application of 18% perfluorohexane vapor in healthy and in oleic acid-injured animals and compare it with an injured control group. DesignProspective randomized controlled study. SettingExperimental research laboratory at a university medical center. SubjectsNineteen sheep weighing 31.4 ± 4.1 kg. InterventionsLung injury was induced in 14 sheep by the intravenous injection of 0.1 mL/kg oleic acid. After establishment of lung injury (Pao2/Fio2ratio, <200; pulmonary artery occlusion pressure, <19 torr), seven animals were treated with 18% perfluorohexane vapor for 30 mins whereas seven animals served as controls. After the start of perfluorohexane treatment, blood gases and respiratory and hemodynamic data were collected in 10-min intervals throughout the study period of 1 hr. In addition, five healthy animals received perfluorohexane vapor for 30 mins and were followed up for 2 hrs to exclude delayed negative effects. Measurements and Main ResultsTreatment of healthy animals with 18% perfluorohexane vapor was not accompanied by any significant adverse effects. It was associated with a significant decrease of alveolar-arterial oxygen difference during perfluorohexane application (p < .05). In injured animals, 18% perfluorohexane led to a sustained improvement of peak inspiratory pressures within 10 mins of treatment (p < .001). The concomitant increase in compliance was equally significant (p < .001). Significant improvements in Pao2 occurred despite a decrease in Fio2 to 0.81 at the end of vaporization. ConclusionHealthy animals tolerated perfluorohexane vapor well without significant changes in oxygenation and mechanical lung function for 2 hrs. In injured animals, application of perfluorohexane vapor primarily improved peak inspiratory pressure and compliance. The increase of oxygenation therefore could be secondary to an improvement in compliance.

hemodynamic Effects Of Hypertonic Hydroxyethyl Starch 6% Solution And Isotonic Hydroxyethyl Starch 6% Solution After Declamping During Abdominal Aortic Aneurysm Repair

Fluid resuscitation with hypertonic hydroxyethyl starch solutions (HES) is effective in haemorrhagic shock due to the rapid mobilisation of fluids into the intravascular compartment. Declamping of the abdominal aorta with acute redistribution of blood into the vessels of the lower body half causes declamping-induced hypotension. Usually large amount of fluids or vasopressors are necessary to restore hemodynamic stability. Therefore, infusion of a hypertonic colloid solution may be an attractive option to achieve hemodynamic stability. This study was conducted to determine the amount of fluid of either hypertonic HES (HES 6%;7.2% NaCl) or isotonic HES (HES 6%;0.9% NaCl) needed to attain best wedge pressure (PCWP) cardiac index (CI) relation after declamping. Thirty-two high-risk patients undergoing elective abdominal aneurysm resection were enrolled in a prospective, randomised, double blinded study. The individual optimised PCWP/CI relation was determined after induction of anaesthesia. After declamping, both solutions were titrated in small boluses of 100 mL until the previously determined best wedge was reached. The amount of fluid after declamping was significantly reduced in the hypertonic HES- group 162 mL vs. 265 mL in the control group (P < 0.05). Resuscitation time was shortened, and cardiac index was slightly higher in the treatment group. The use of hypertonic HES-solution after aortic declamping led to a significant reduction of fluids necessary to attain optimised PCWP/CI relation. In this clinical trial with moderate blood loss in high-risk patients, hypertonic HES applied in a titrated fashion restored hemodynamic stability faster and without volume overload.

Effects of perfluorohexane vapor on relative blood flow distribution in an animal model of surfactant-depleted lung injury.

Objective To test the hypothesis that treatment with vaporized perfluorocarbon affects the relative pulmonary blood flow distribution in an animal model of surfactant-depleted acute lung injury. Design Prospective, randomized, controlled trial. Setting A university research laboratory. Subjects Fourteen New Zealand White rabbits (weighing 3.0–4.5 kg). Interventions The animals were ventilated with an Fio2 of 1.0 before induction of acute lung injury. Acute lung injury was induced by repeated saline lung lavages. Eight rabbits were randomized to 60 mins of treatment with an inspiratory perfluorohexane vapor concentration of 0.2 in oxygen. To compensate for the reduced Fio2 during perfluorohexane treatment, Fio2 was reduced to 0.8 in control animals. Change in relative pulmonary blood flow distribution was assessed by using fluorescent-labeled microspheres. Measurements and Main Results Microsphere data showed a redistribution of relative pulmonary blood flow attributable to depletion of surfactant. Relative pulmonary blood flow shifted from areas that were initially high-flow to areas that were initially low-flow. During the study period, relative pulmonary blood flow of high-flow areas decreased further in the control group, whereas it increased in the treatment group. This difference was statistically significant between the groups (p = .02) as well as in the treatment group compared with the initial injury (p = .03). Shunt increased in both groups over time (control group, 30% ± 10% to 63% ± 20%; treatment group, 37% ± 20% to 49% ± 23%), but the changes compared with injury were significantly less in the treatment group (p = .03). Conclusion Short treatment with perfluorohexane vapor partially reversed the shift of relative pulmonary blood flow from high-flow to low-flow areas attributable to surfactant depletion.

Standard operating procedures und OP-Management zur Steigerung der Patientensicherheit und der Effizienz von Prozessabläufen

Financial pressures have led the way more efficiency in health care management. To decrease hospital costs a more proficient use of personal resources is required. The drive to increase efficiency with the concomitant increase in workload can cause a reduction in quality of patient care and of patient security. A professional operating room (OR) management and the introduction of standard operating procedures (SOP) have helped to optimise workflow in and around the OR. OR management can control an efficient workflow and generate data concerning performance, costs and quality. SOPs lead to a standardisation of workflow in the OR and in patient treatment modalities. This guaranties a high quality in patient care and more safety despite an increase in work-load.

Pretreatment with perfluorohexane vapor attenuates fMLP-induced lung injury in isolated perfused rabbit lungs

ABSTRACT The authors investigated the protective effects and dose dependency of perfluorohexane (PFH) vapor on leukocyte-mediated lung injury in isolated, perfused, and ventilated rabbit lungs. Lungs received either 18 vol.% (n = 7), 9 vol.% (n = 7), or 4.5 vol.% (n = 7) PFH. Fifteen minutes after beginning of PFH application, lung injury was induced with formyl-Met-Leu-Phe (fMLP). Control lungs (n = 7) received fMLP only. In addition 5 lungs (PFH-sham) remained uninjured receiving 18 vol.% PFH only. Pulmonary artery pressure (mPAP), peak inspiratory pressure (Pmax), and lung weight were monitored for 90 minutes. Perfusate samples were taken at regular intervals for analysis and representative lungs were fixed for histological analysis. In the control, fMLP application led to a significant increase of mPAP, Pmax, lung weight, and lipid mediators. Pretreatment with PFH attenuated the rise in these parameters. This was accompanied by preservation of the structural integrity of the alveolar architecture and air-blood barrier. In uninjured lungs, mPAP, Pmax, lung weight, and lipid mediator formation remained uneffected in the presence of PFH. The authors concluded that pretreatment with PFH vapor leads to an attenuation of leukocyte-mediated lung injury. Vaporization of perfluorocarbons (PFCs) offers new therapeutic options, making use of their protective and anti-inflammatory properties in prophylaxis or in early treatment of acute lung injury.

Effects of perfluorohexane vapor in the treatment of experimental lung injury

RATIONALE We investigated the effects of vaporized perfluorohexane (PFH) on pulmonary vascular tone, pulmonary vascular resistance and peak inspiratory pressure as well as lipid mediator formation in the treatment of calcium ionophore induced lung injury in a model of the isolated perfused and ventilated rabbit lungs. METHODS Lung injury was induced in isolated perfused and ventilated rabbit lungs by calcium ionophore A23187. Lungs were treated with either 4.5 vol.% (4.5 vol.% PFH; n = 6) or 18 vol.% (18 vol.% PFH; n = 6) PFH. Six lungs remained untreated (Control). In addition 5 lungs (PFH-sham) remained uninjured receiving 18 vol.% PFH only. Mean pulmonary artery pressure (mPAP), peak inspiratory pressure (P(max)), and lung weight (weight) were monitored for 120 min. Experiments were terminated before when the increase in lung weight exceeded 40 g. Perfusate samples were taken at regular intervals for analysis of TXB(2), 6-keto-PGF(1) and LTB(4). RESULTS Controls reached the study end point significantly earlier than both PFH groups. Significant differences were found for a weight gain of 10 g and 20 g between the control and the 4.5 vol.% PFH and the 18 vol.% PFH. Differences in mPAP were more pronounced in the 4.5 vol.% PFH. However increases in P(max) were more marked in 4.5 vol.% PFH. TXA(2)-, PGI(2)-, and LTB(4)-levels were significantly lower in PFH groups. Uninjured lungs remained unaffected by the presence of 18 vol.% PFH. CONCLUSION Inflammatory lung injury was attenuated by the treatment with 4.5 vol.% PFH and 18 vol.% PFH vapor in the isolated perfused rabbit lung. Therapeutic effects were more pronounced with a concentration of 4.5 vol.% PFH.

Pilot study of vaporization of perfluorohexane during high-frequency oscillatory ventilation in experimental acute lung injury

ABSTRACT Inhalation of perfluorohexane vapor (PFH) and high-frequency oscillatory ventilation (HFOV) both have been shown to improve lung function in acute lung injury (ALI). Their combination implies synergistic action. The authors investigated technical aspects of PFH vaporization during HFOV and effects on gas exchange in a pilot study of experimental ALI. Eighteen anesthetized sheep were randomly assigned to HFOV or HFOV with PFH inhalation after oleic acid–induced ALI. HFOV was set to a continuous distending pressure of 25 cm H2O, and an oscillation of 80 to 100 cm H2O at a frequency of 5 Hz. PFH vapor was delivered by means of bypassed high-flow oxygen through a thin endotracheal tube. PFH concentration was measured by infrared absorption. Blood gases and hemodynamic data were taken. Pao2 significantly increased from 9.1 ± 0.9 to 32.7 ± 9.5 kPa (mean ± SEM) in the HFOV group and from 12.5 ± 1.1 to 27.0 ± 6.8 kPa in the HFOV PFH group. Paco2 significantly decreased from 6.3 ± 0.3 to 5.5 ± 0.5 kPa in the HFOV group and from 5.7 ± 0.4 to 4.9 ± 0.5 kPa in the HFOV PFH group. Changes in gas exchange were not different between groups. These results show that the inhalation of PFH during HFOV is technically feasible, but did not enhance gas exchange in a 210-minute observation period of experimental ALI.

Standard operating procedures und OP-Management zur Steigerung der Patientensicherheit und der Effizienz von Prozessabläufen@@@Standard operating procedures and operating room management: Improvement of patient safety and the efficiency of processes

Financial pressures have led the way more efficiency in health care management. To decrease hospital costs a more proficient use of personal resources is required. The drive to increase efficiency with the concomitant increase in workload can cause a reduction in quality of patient care and of patient security. A professional operating room (OR) management and the introduction of standard operating procedures (SOP) have helped to optimise workflow in and around the OR. OR management can control an efficient workflow and generate data concerning performance, costs and quality. SOPs lead to a standardisation of workflow in the OR and in patient treatment modalities. This guaranties a high quality in patient care and more safety despite an increase in work-load.

SPATIAL PULMONARY FLOW DISTRIBUTION IN RABBIT ISOLATED LUNGS IS A POOR REPRESENTATION OF THE SITUATION IN VIVO

1 Isolated lung preparations are established to investigate effects on pulmonary vascular tone and spatial pulmonary flow (Q̇rel) distribution. In the present study, we hypothesized that Q̇rel distribution in isolated lungs is only poorly correlated with the in vivo situation. 2 Fourteen rabbits were anaesthetized and mechanically ventilated with room air. Animals were held in an upright position for 15 min and Q̇rel was assessed using fluorescent microspheres (Q̇rel‐in vivo). A second injection of microspheres was made after isolation of the lungs (Q̇rel‐ex vivo). Lungs were dried, cut into 1 cm3 cubes and spatial Q̇rel distributions were analysed. 3 The mean correlation of Q̇rel‐in vivo and Q̇rel‐ex vivo was 0.592 ± 0.188 (95% confidence interval 0.493–0.690). The Q̇rel was redistributed to more ventral (the mean slope of Q̇rel vs the dorsal–ventral axis changed from −0.289 ± 0.227 to −0.147 ± 0.114; P = 0.03), cranial (mean slope of Q̇rel vs the caudal–cranial axis changed from −0.386 ± 0.193 to −0.176 ± 0.142; P < 0.001) and central (mean slope of Q̇rel vs the hilus–peripheral axis changed from 0.436 ± 0.133 to −0.236 ± 0.159; P = 0.003) lung areas. 4 The results obtained from studies investigating Q̇rel distributions in isolated lung models must be interpreted cautiously because the isolated lung set‐up significantly affects the spatial distribution of pulmonary flow.