Dependence of lung injury on inflation rate during low-volume ventilation in normal open-chest rabbits

2004 ◽  
Vol 97 (1) ◽  
pp. 260-268 ◽  
Author(s):  
Edgardo D'Angelo ◽  
Matteo Pecchiari ◽  
Marina Saetta ◽  
Elisabetta Balestro ◽  
Joseph Milic-Emili
Keyword(s):  
Airway Resistance ◽  
Lung Mechanics ◽  
Mechanically Ventilated ◽  
Peripheral Airways ◽  
Open Chest ◽  
Volume Ventilation ◽  
High Inflation ◽  
Group A ◽  
Group B ◽  
Alveolar Septa

Lung mechanics and morphometry were assessed in two groups of nine normal open-chest rabbits mechanically ventilated (MV) for 3–4 h at zero end-expiratory pressure (ZEEP) with physiological tidal volumes (Vt; 11 ml/kg) and high ( group A) or low ( group B) inflation flow (44 and 6.1 ml·kg−1·s−1, respectively). Relative to initial MV on positive end-expiratory pressure (PEEP; 2.3 cmH2O), MV on ZEEP increased quasi-static elastance and airway and viscoelastic resistance more in group A (+251, +393, and +225%, respectively) than in group B (+180, +247, and +183%, respectively), with no change in viscoelastic time constant. After restoration of PEEP, quasi-static elastance and viscoelastic resistance returned to control, whereas airway resistance, still relative to initial values, remained elevated more in group A (+86%) than in group B (+33%). In contrast, prolonged high-flow MV on PEEP had no effect on lung mechanics of seven open-chest rabbits ( group C). Gas exchange on PEEP was equally preserved in all groups, and the lung wet-to-dry ratios were normal. Relative to group C, both groups A and B had an increased percentage of abnormal alveolar-bronchiolar attachments and number of polymorphonuclear leukocytes in alveolar septa, the latter being significantly larger in group A than in group B. Thus prolonged MV on ZEEP with cyclic opening-closing of peripheral airways causes alveolar-bronchiolar uncoupling and parenchymal inflammation with concurrent, persistent increase in airway resistance, which are worsened by high-inflation flow.

Low-volume ventilation causes peripheral airway injury and increased airway resistance in normal rabbits

2002 ◽  
Vol 92 (3) ◽  
pp. 949-956 ◽  
Author(s):  
Edgardo D'Angelo ◽  
Matteo Pecchiari ◽  
Paolo Baraggia ◽  
Marina Saetta ◽  
Elisabetta Balestro ◽  
...  
Keyword(s):  
Progressive Increase ◽  
Lung Mechanics ◽  
Mechanically Ventilated ◽  
Peripheral Airways ◽  
Airway Injury ◽  
Volume Ventilation ◽  
Peripheral Airway ◽  
Group A ◽  
Group B ◽  
Opening And Closing

Lung mechanics and morphometry of 10 normal open-chest rabbits ( group A), mechanically ventilated (MV) with physiological tidal volumes (8–12 ml/kg), at zero end-expiratory pressure (ZEEP), for 3–4 h, were compared with those of five rabbits ( group B) after 3–4 h of MV with a positive end-expiratory pressure (PEEP) of 2.3 cmH2O. Relative to initial MV on PEEP, MV on ZEEP caused a progressive increase in quasi-static elastance (+36%) and airway (Rint; +71%) and viscoelastic resistance (+29%), with no change in the viscoelastic time constant. After restoration of PEEP, quasi-static elastance and viscoelastic resistance returned to control levels, whereas Rint remained elevated (+22%). On PEEP, MV had no effect on lung mechanics. Gas exchange on PEEP was equally preserved in groups A and B, and the lung wet-to-dry ratios were normal. Both groups had normal alveolar morphology, whereas only group A had injured respiratory and membranous bronchioles. In conclusion, prolonged MV on ZEEP induces histological evidence of peripheral airway injury with a concurrent increase in Rint, which persists after restoration of normal end-expiratory volumes. This is probably due to cyclic opening and closing of peripheral airways on ZEEP.

Dependence of lung injury on surface tension during low-volume ventilation in normal open-chest rabbits

2007 ◽  
Vol 102 (1) ◽  
pp. 174-182 ◽  
Author(s):  
Edgardo D’Angelo ◽  
Matteo Pecchiari ◽  
Guendalina Gentile
Keyword(s):  
Lung Injury ◽  
The Other ◽  
Lung Mechanics ◽  
Exogenous Surfactant ◽  
Lung Edema ◽  
Edema Formation ◽  
Open Chest ◽  
Group A ◽  
Group B ◽  
Group D

To evaluate the role of pulmonary surfactant in the prevention of lung injury caused by mechanical ventilation (MV) at low end-expiratory volumes, lung mechanics and morphometry were assessed in three groups of eight normal, open-chest rabbits ventilated for 3–4 h at zero end-expiratory pressure (ZEEP) with physiological tidal volumes (Vt = 10 ml/kg). One group was left untreated ( group A); the other two received surfactant intratracheally ( group B) or aerosolized dioctylsodiumsulfosuccinate ( group C) before MV on ZEEP. Relative to initial MV on positive end-expiratory pressure (PEEP; 2.3 cmH2O), quasi-static elastance (Est) and airway (Rint) and viscoelastic resistance (Rvisc) increased on ZEEP in all groups. After restoration of PEEP, only Rint (124%) remained elevated in group A, only Est (36%) was significantly increased in group B, whereas in group C, Est, Rint, and Rvisc were all markedly augmented (274, 253, and 343%). In contrast, prolonged MV on PEEP had no effect on lung mechanics of eight open-chest rabbits ( group D). Lung edema developed in group C (wet-to-dry ratio = 7.1), but not in the other groups. Relative to group D, both groups A and C, but not B, showed histological indexes of bronchiolar injury, whereas all groups exhibited an increased number of polymorphonuclear leukocytes in alveolar septa, which was significantly greater in group C. In conclusion, administration of exogenous surfactant largely prevents the histological and functional damage of prolonged MV at low lung volumes, whereas surfactant dysfunction worsens the functional alterations, also because of edema formation and, possibly, increased inflammatory response.

scholarly journals ABO groups can play a role in susceptibility and severity of COVID-19

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
S. Samra ◽  
M. Habeb ◽  
R. Nafae
Keyword(s):  
Blood Group ◽  
Abo Blood Group ◽  
Infection Group ◽  
Mechanically Ventilated ◽  
Blood Group A ◽  
Group A ◽  
Study Population ◽  
Group B ◽  
The Relationship ◽  
Seriously Ill

Abstract Background A few people infected by the coronavirus become seriously ill, while others show little to no signs of the symptoms, or are asymptomatic. Recent researches are pointing to the fact that the ABO blood group might play an important role in a person’s susceptibility and severity of COVID-19 infection. Aim of the study: try to understand the relationship between ABO groups and COVID-19 (susceptibility and severity). Results A total of (507) patients were included in this study. The study population was divided based on the ABO blood group into types A+, A−, B+, AB, O+, and O−. Blood group A was associated with high susceptibility of infection: group A, 381 (75.1%); and less common in group O, 97 (19.2%), group B, 18 (3.5%), and group AB, 11 (2.2%). The severity of COVID-19 infection was common in non-blood group O where (20 (7.1%), 4 (26.7%), 2 (11%), and 1 (9%) in type A+, A−, B+, and AB, respectively), while in type O 3.1%. And mechanically ventilated patients were 22 (5.9%), 2 (13.4%), 2 (11.1%), and 1 (1%). Mortality was high in blood groups A and B, 16 (4.37%) and 1 (5.5%), respectively, while in blood group O, it was 1%. Conclusion The incidence, severity, and mortality of COVID-19 were common in non-blood group O. While blood group O was protected against COVID-19.

scholarly journals Control of Imported and Acquired Methicillin-resistant Staphylococcus aureus (MRSA) in Mechanically Ventilated Patients: A Dose-response Study of Enteral Vancomycin to Reduce Absolute Carriage and Infection

2005 ◽  
Vol 33 (3) ◽  
pp. 361-372 ◽  
Author(s):  
M. Viviani ◽  
H. K. F. Van Saene ◽  
R. Dezzoni ◽  
L. Silvestri ◽  
R. Di Lenarda ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
First Year ◽  
High Dose ◽  
Mechanically Ventilated ◽  
Group A ◽  
Second Year ◽  
The Absolute ◽  
Group B ◽  
Dose Response Study ◽  
The Impact

This study aimed to quantify the animate source provided by the patients using the concept of “absolute carriage” by multiplying the carrier rate by the level of carriage; and to compare the impact of a low and high dose of an oropha-ryngeal vancomycin gel on the absolute MRSA carriage and infection. In all, 265 patients were included, 126 were MRSA positive. Fifty-five patients received 2% vancomycin gel during the first year whilst 4% vancomycin gel was given to 50 patients during the second year. Surveillance swabs of throat and rectum were obtained from all eligible patients on admission and then twice weekly. The vancomycin protocol was started as soon as the surveillance cultures were positive for MRSA. Those patients received one gram of enteral vancomycin daily, divided into four doses. During the first year 2% vancomycin gel 4 ml (80 mg) was applied in the oropharynx in four doses in addition to the enteral solution (Group A). During the second year 4% vancomycin gel 4 ml (160 mg) was used (Group B). The absolute carriage was high during both periods: 3.6 for Group A, and 3.2 for Group B. The 4% vancomycin protocol significantly reduced the absolute carriage, compared to the 2% vancomycin protocol: 2.6 versus 1.5 (P<0.01). Significant reduction in secondary endogenous infections was found in the second year: seven versus 15 patients (P<0.05). A total of 3,588 microbiological samples were processed. Neither Staphylococcus aureus with intermediate sensitivity to vancomycin (VISA) nor vancomycin-resistant enterococci (VRE) were detected.

scholarly journals The Effect of Manual Lung Hyperinflation and Postural Drainage on Pulmonary Complications in Mechanically Ventilated Trauma Patients

1998 ◽  
Vol 26 (5) ◽  
pp. 492-496 ◽  
Author(s):  
G. Ntoumenopoulos ◽  
A. Gild ◽  
D. J. Cooper
Keyword(s):  
Nosocomial Pneumonia ◽  
Pulmonary Complications ◽  
Control Group ◽  
Trauma Patients ◽  
Mechanically Ventilated ◽  
Clinical Criteria ◽  
Lung Hyperinflation ◽  
Postural Drainage ◽  
Group A ◽  
Group B

This study questioned whether manual lung hyperinflation (MHI) and postural drainage reduced the incidence of nosocomial pneumonia or improved other outcome variables in mechanically ventilated trauma patients. Patients were withdrawn from the study if they developed nosocomial pneumonia according to a predetermined definition or on the clinical suspicion of nosocomial pneumonia by the attending intensivist. Of the 46 patients who fulfilled all the inclusion criteria and were enrolled into the study, 22 patients were randomized to group A (physiotherapy) and 24 patients to group B (control group). Twice as many patients were withdrawn in group B (8/24) compared with group A (4/22), although the differences were not statistically significant, [X2(1, 1) = 1.36, P = 0.24]. The length of time receiving mechanical ventilation and in the ICU was similar between the two groups and there were no differences in pulmonary dysfunction (“worst” daily PaO2/FiO2 ratio) between the two groups. There were no ICU deaths in either group. Physiotherapy as used in this study was not associated with a reduced incidence of nosocomial pneumonia based on standard clinical criteria. Nevertheless the trend to more frequent nosocomial pneumonia in the control patients suggests that a larger study in more severely injured patients with stricter clinical criteria for the definition of nosocomial pneumonia is indicated.

scholarly journals A comparative study between effect of combined intravenous and nebulized amikacin versus intravenous amikacin alone in mechanically ventilated patients with ventilator-associated pneumonia (VAP)

2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Dalia M. El Fawy ◽  
Azza Yousef Ibrahim ◽  
Ahmed Mostafa Mohamed Abdulmageed ◽  
Eman Abo Bakr El Seddek
Keyword(s):  
Mechanical Ventilation ◽  
Ventilator Associated Pneumonia ◽  
Icu Mortality ◽  
Mechanically Ventilated ◽  
Mechanically Ventilated Patients ◽  
Icu Stay ◽  
Drug Concentrations ◽  
Group A ◽  
Group B ◽  
Ventilated Patients

Abstract Background Aerosolized antibiotic administration offers the theoretical advantages of achieving high drug concentrations at the infection site together with lower systemic absorption. This study aims to compare the effect of combining nebulized amikacin with intravenous amikacin to the effect of the usual intravenous route alone in the treatment of patients with ventilator-associated pneumonia and its impact on the duration of mechanical ventilation, laboratory, and clinical picture of the patients. Results This study was carried out on 64 mechanically ventilated patients with Gram-negative VAP. The patients were divided into 2 groups. Group A included 32 patients treated with nebulized amikacin plus IV amikacin, and group B included 32 patients treated with IV amikacin alone. The duration of treatment for both groups was 8 days with a daily assessment of Clinical Pulmonary Infection Score (CPIS) and monitoring of clinical and laboratory parameters. Sputum cultures were obtained thereafter. In our study, the CPIS score and overall ICU mortality were less in the nebulized than in the IV group but the difference failed to be statistically significant. Increase of oxygenation level (Pao2/Fio2 ratio), organism clearance, decrease in serum creatinine level, duration of mechanical ventilation, and length of ICU stay were significantly different in favor of group A than group B. Conclusion Nebulized and IV amikacin offered better oxygenation, organism clearance, less nephrotoxicity, and less duration of mechanical ventilation and ICU stay than the IV group. Combined and IV routes were comparable regarding the decrease in CPIS score and ICU mortality with no significant difference between them. However, we prefer to use the combined regimen for the mentioned reasons. Further large-scale studies are required to confirm these findings and to establish a definite conclusion.

scholarly journals Prospective Observational Study to Evaluate the Effect of Different Levels of Positive End-Expiratory Pressure on Lung Mechanics in Patients with and without Acute Respiratory Distress Syndrome

2020 ◽  
Vol 9 (8) ◽  
pp. 2446
Author(s):  
Mascha O. Fiedler ◽  
Dovile Diktanaite ◽  
Emilis Simeliunas ◽  
Maximilian Pilz ◽  
Armin Kalenka
Keyword(s):  
Peak Inspiratory Pressure ◽  
Transpulmonary Pressure ◽  
Driving Pressure ◽  
Lung Mechanics ◽  
Lung Protective Ventilation ◽  
Intraabdominal Pressure ◽  
Control Group ◽  
Positive End Expiratory Pressure ◽  
Group A ◽  
Group B

Background: The optimal level of positive end-expiratory pressure is still under debate. There are scare data examining the association of PEEP with transpulmonary pressure (TPP), end-expiratory lung volume (EELV) and intraabdominal pressure in ventilated patients with and without ARDS. Methods: We analyzed lung mechanics in 3 patient groups: group A, patients with ARDS; group B, obese patients (body mass index (BMI) > 30 kg/m2) and group C, a control group. Three levels of PEEP (5, 10, 15 cm H2O) were used to investigate the consequences for lung mechanics. Results: Fifty patients were included, 22 in group A, 18 in group B (BMI 38 ± 2 kg/m2) and 10 in group C. At baseline, oxygenation showed no differences between the groups. Driving pressure (ΔP) and transpulmonary pressure (ΔPL) was higher in group B than in groups A and C at a PEEP of 5 cm H2O (ΔP A: 15 ± 1, B: 18 ± 1, C: 14 ± 1 cm H2O; ΔPL A: 10 ± 1, B: 13 ± 1, C: 9 ± 0 cm H2O). Peak inspiratory pressure (Pinsp) rose in all groups as PEEP increased, but the resulting driving pressure and transpulmonary pressure were reduced, whereas EELV increased. Conclusion: Measuring EELV or TPP allows a personalized approach to lung-protective ventilation.

An ultrastructural study of sertoli cells in two geographically isolated populations of Aphanius dispar

1992 ◽  
Vol 50 (1) ◽  
pp. 548-549
Author(s):  
Taber A. Ba-Omar ◽  
Philip F. Prentis
Keyword(s):  
Ultrastructural Level ◽  
Uranyl Acetate ◽  
Freshwater Teleost ◽  
Isolated Populations ◽  
En Bloc ◽  
The North ◽  
Group A ◽  
Ultrathin Sections ◽  
Group B ◽  
Geographically Isolated

We have recently carried out a study of spermiogenic differentiation in two geographically isolated populations of Aphanius dispar (freshwater teleost), with a view to ascertaining variation at the ultrastructural level. The sampling areas were the Jebel Al Akhdar in the north (Group A) and the Dhofar region (Group B) in the south. Specimens from each group were collected, the testes removed, fixed in Karnovsky solution, post fixed in OsO, en bloc stained with uranyl acetate and then routinely processed to Agar 100 resin, semi and ultrathin sections were prepared for study.

Comparison of one-year prognosis of patients classified as chronic critical lower limb ischaemia according to TASC II or European consensus definition in the COPART cohort

VASA ◽  
2015 ◽  
Vol 44 (3) ◽  
pp. 0220-0228 ◽  
Author(s):  
Marion Vircoulon ◽  
Carine Boulon ◽  
Ileana Desormais ◽  
Philippe Lacroix ◽  
Victor Aboyans ◽  
...  
Keyword(s):  
Medical Treatment ◽  
Critical Limb Ischaemia ◽  
Limb Ischaemia ◽  
Medical Group ◽  
Consensus Definition ◽  
Transcutaneous Oxygen ◽  
European Consensus ◽  
Group A ◽  
One Year ◽  
Group B

Background: We compared one-year amputation and survival rates in patients fulfilling 1991 European consensus critical limb ischaemia (CLI) definition to those clas, sified as CLI by TASC II but not European consensus (EC) definition. Patients and methods: Patients were selected from the COPART cohort of hospitalized patients with peripheral occlusive arterial disease suffering from lower extremity rest pain or ulcer and who completed one-year follow-up. Ankle and toe systolic pressures and transcutaneous oxygen pressure were measured. The patients were classified into two groups: those who could benefit from revascularization and those who could not (medical group). Within these groups, patients were separated into those who had CLI according to the European consensus definition (EC + TASC II: group A if revascularization, group C if medical treatment) and those who had no CLI by the European definition but who had CLI according to the TASC II definition (TASC: group B if revascularization and D if medical treatment). Results: 471 patients were included in the study (236 in the surgical group, 235 in the medical group). There was no difference according to the CLI definition for survival or cardiovascular event-free survival. However, major amputations were more frequent in group A than in group B (25 vs 12 %, p = 0.046) and in group C than in group D (38 vs 20 %, p = 0.004). Conclusions: Major amputation is twice as frequent in patients with CLI according to the historical European consensus definition than in those classified to the TASC II definition but not the EC. Caution is required when comparing results of recent series to historical controls. The TASC II definition of CLI is too wide to compare patients from clinical trials so we suggest separating these patients into two different stages: permanent (TASC II but not EC definition) and critical ischaemia (TASC II and EC definition).

Absorbable suture material in carotid surgery

VASA ◽  
2015 ◽  
Vol 44 (6) ◽  
pp. 451-457 ◽  
Author(s):  
Vincenzo Gasbarro ◽  
Luca Traina ◽  
Francesco Mascoli ◽  
Vincenzo Coscia ◽  
Gianluca Buffone ◽  
...  
Keyword(s):  
Suture Material ◽  
Absorbable Suture ◽  
Paediatric Surgery ◽  
Carotid Surgery ◽  
Suture Materials ◽  
Absorbable Suture Material ◽  
Absorbable Sutures ◽  
Group A ◽  
Group B

Abstract. Background: Absorbable sutures are not generally accepted by most vascular surgeons for the fear of breakage of the suture line and the risk of aneurysmal formation, except in cases of paediatric surgery or in case of infections. Aim of this study is to provide evidence of safety and efficacy of the use of absorbable suture materials in carotid surgery. Patients and methods: In an 11 year period, 1126 patients (659 male [58.5 %], 467 female [41.5 %], median age 72) underwent carotid endarterectomy for carotid stenosis by either conventional with primary closure (cCEA) or eversion (eCEA) techniques. Patients were randomised into two groups according to the type of suture material used. In Group A, absorbable suture material (polyglycolic acid) was used and in Group B non-absorbable suture material (polypropylene) was used. Primary end-point was to compare severe restenosis and aneurysmal formation rates between the two groups of patients. For statistical analysis only cases with a minimum period of follow-up of 12 months were considered. Results: A total of 868 surgical procedures were considered for data analysis. Median follow-up was 6 years (range 1-10 years). The rate of postoperative complications was better for group A for both cCEA and eCEA procedures: 3.5 % and 2.0 % for group A, respectively, and 11.8 % and 12.9 % for group B, respectively. Conclusions: In carotid surgery, the use of absorbable suture material seems to be safe and effective and with a general lower complications rate compared to the use of non-absorbable materials.

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