Effects of positive end-expiratory pressure on respiratory function and hemodynamics in patients with acute respiratory failure with and without intra-abdominal hypertension: a pilot study

INTRODUCTION: To investigate the effects of positive end-expiratory pressure (PEEP) on respiratory function and hemodynamics in patients with acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) with normal intra-abdominal pressure (IAP or= 12 mmHg) during lung protective ventilation and a decremental PEEP, a prospective, observational clinical pilot study was performed. METHODS: Twenty patients with ALI/ARDS with normal IAP or IAH treated in the surgical intensive care unit in a university hospital were studied. The mean IAP in patients with IAH and normal IAP was 16 +/- 3 mmHg and 8 +/- 3 mmHg, respectively (P < 0.001). At different PEEP levels (5, 10, 15, 20 cmH2O) we measured respiratory mechanics, partitioned into its lung and chest wall components, alveolar recruitment, gas-exchange, hemodynamics, extravascular lung water index (EVLWI) and intrathoracic blood volume index (ITBVI). RESULTS: We found that ALI/ARDS patients with IAH, as compared to those with normal IAP, were characterized by: a) no differences in gas-exchange, respiratory mechanics, partitioned into its lung and chest wall components, as well as hemodynamics and EVLWI/ITBVI; b) decreased elastance of the respiratory system and the lung, but no differences in alveolar recruitment and oxygenation or hemodynamics, when PEEP was increased at 10 and 15cmH2O; c) at higher levels of PEEP, EVLWI was lower in ALI/ARDS patients with IAH as compared with those with normal IAP. CONCLUSIONS: IAH, within the limits of IAP measured in the present study, does not affect interpretation of respiratory mechanics, alveolar recruitment and hemodynamics

Post-traumatic changes in energy expenditure and body composition in patients with acute spinal cord injury

Study design: Prospective cohort study. Objective: To investigate the changes in resting energy expenditure and body composition over time in a cohort of patients with spinal cord injury during acute treatment, rehabilitation, and 2 years after the end of rehabilitation. Methods: Adult patients admitted for acute treatment and rehabilitation after traumatic spinal cord injury were recruited. Measurements of resting energy expenditure and body composition were scheduled at 2, 6, 10 and 14 weeks after spinal cord injury, at the end of rehabilitation, and 2 years later. Results: Patients’ mean age was 38.8 years (standard deviation 14.0). Resting energy expenditure began to decrease up to the 10-week measurement (p = 0.02) and further decreased after the 130-week measurement (p < 0.001). Body weight was already decreased after the 6-week measurement (p < 0.01) and increased after the end of rehabilitation (p = 0.009). Percentage body fat mass showed similar changes. Conclusion: After an initial decrease in resting energy expenditure, body weight and percentage of body fat, these values levelled off during the rehabilitation period. After the end of the rehabilitation period, body weight and body fat mass increased again to the baseline levels, whereas resting energy expenditure decreased further. These results suggest that rehabilitation programmes should focus on adapting to these foreseeable changes

Positive end-expiratory pressure titrated according to respiratory system mechanics or to ARDSNetwork table did not guarantee positive end-expiratory transpulmonary pressure in acute respiratory distress syndrome

Purpose: Pulmonary recruitment and positive end-expiratory pressure (PEEP) titrated according to minimal static elastance of the respiratory system (PEEP Estat,RS ) compared to PEEP set according to the ARDSNetwork table (PEEP ARDSNetwork ) as a strategy to prevent ventilator-associated lung injury (VALI) in patients with acute respiratory distress syndrome (ARDS) increases mortality. Alternatively, avoiding negative end-expiratory transpulmonary pressure has been discussed as superior PEEP titration strategy. Therefore, we tested whether PEEP Estat,RS or PEEP ARDSNetwork prevent negative end-expiratory transpulmonary pressure in ARDS patients. Material and methods: Thirteen patients with moderate to severe ARDS were studied at PEEP ARDSNetwork versus PEEP Estat,RS . Patients were then grouped post hoc according to the end-expiratory transpulmonary pressure (positive or negative). Results: 7 out of 13 patients showed negative end-expiratory transpulmonary pressures (Ptp 12) with both strategies (PEEP ARDSNetwork : - 5.4 \ub1 3.5 vs. 2.2 \ub1 3.7 cm H 2 O, p =.005; PEEP Estat,RS : - 3.6 \ub1 1.5 vs. 3.5 \ub1 3.3 cm H 2 O, p <.001). Ptp 12 was associated with higher intra-abdominal pressure and lower end-expiratory lung volume with both PEEP strategies. Conclusions: In patients with moderate-to-severe ARDS, PEEP titrated according to the minimal static elastance of the respiratory system or according to the ARDSNetwork table did not prevent negative end-expiratory transpulmonary pressure

Prospective Evaluation of Laparoscopic Sacrocolpopexy with Concomitant Laparoscopic-Assisted Total Vaginal Hysterectomy

(1) Background: Sacrocolpopexy (SCP) with subtotal hysterectomy (SH) is a standard procedure for the treatment of utero-vaginal prolapse. Several disadvantages are associated with the remaining cervix; therefor, SCP with total hysterectomy (TH) may be preferred. According to some publications, SCP with concomitant TH is associated with higher rates of mesh extrusion. Our hypothesis is that mesh extrusion at the apex can be avoided through prevention of thermal injury and through vaginal cuff suturing when performing the laparoscopic sacrocolpopexy combined with a laparoscopic-assisted vaginal total hysterectomy (LAVH). (2) Methods: This prospective cohort study was performed from 2016 until January 2019 including women with a utero-vaginal prolapse undergoing laparoscopic SCP with LAVH. The SCP was performed utilizing a non-absorbable polypropylene macroporous mesh (EndoGYNious&reg;). The primary outcome was the mesh extrusion rate after SCP with concomitant LAVH. The secondary outcome was the objective and functional outcome. (3) There were 50 women included in this prospective cohort. At follow up of 6&ndash;12 weeks postoperatively, no mesh extrusion was detected and objectified. Overall, all women showed excellent anatomical and functional outcome. The median time from surgery was 42 months. (4) Laparoscopic SCP with concomitant LAVH showed no increased risk of mesh extrusion and good objective and functional outcomes

Transpulmonary thermodilution in patients treated with veno-venous extracorporeal membrane oxygenation

Background!#!We tested the effect of different blood flow levels in the extracorporeal circuit on the measurements of cardiac stroke volume (SV), global end-diastolic volume index (GEDVI) and extravascular lung water index derived from transpulmonary thermodilution (TPTD) in 20 patients with severe acute respiratory distress syndrome (ARDS) treated with veno-venous extracorporeal membrane oxygenation (ECMO).!##!Methods!#!Comparative SV measurements with transesophageal echocardiography and TPTD were performed at least 5 times during the treatment of the patients. The data were interpreted with a Bland-Altman analysis corrected for repeated measurements. The interchangeability between both measurement modalities was calculated and the effects of extracorporeal blood flow on SV measurements with TPTD was analysed with a linear mixed effect model. GEDVI and EVLWI measurements were performed immediately before the termination of the ECMO therapy at a blood flow of 6 l/min, 4 l/min and 2 l/min and after the disconnection of the circuit in 7 patients.!##!Results!#!170 pairs of comparative SV measurements were analysed. Average difference between the two modalities (bias) was 0.28 ml with an upper level of agreement of 40 ml and a lower level of agreement of -39 ml within a 95% confidence interval and an overall interchangeability rate between TPTD and Echo of 64%. ECMO blood flow did not influence the mean bias between Echo and TPTD (0.03 ml per l/min of ECMO blood flow; p = 0.992; CI - 6.74 to 6.81). GEDVI measurement was not significantly influenced by the blood flow in the ECMO circuit, whereas EVLWI differed at a blood flow of 6 l/min compared to no ECMO flow (25.9 ± 10.1 vs. 11.0 ± 4.2 ml/kg, p = 0.0035).!##!Conclusions!#!Irrespectively of an established ECMO therapy, comparative SV measurements with Echo and TPTD are not interchangeable. Such caveats also apply to the interpretation of EVLWI, especially with a high blood flow in the extracorporeal circulation. In such situations, the clinician should rely on other methods of evaluation of the amount of lung oedema with the haemodynamic situation, vasopressor support and cumulative fluid balance in mind.!##!Trial registration!#!German Clinical Trials Register (DRKS00021050). Registered 03/30/2020 https://www.drks.de/drks_web/navigate.do?navigationId=trial.HTML&amp;amp;TRIAL_ID=DRKS00017237

Open lung approach with low tidal volume mechanical ventilation attenuates lung injury in rats with massive brain damage

The ideal ventilation strategy for patients with massive brain damage requires better elucidation. We hypothesized that in the presence of massive brain injury, a ventilation strategy using low (6 milliliters per kilogram ideal body weight) tidal volume (VT) ventilation with open lung positive end-expiratory pressure (LVT/OLPEEP) set according to the minimal static elastance of the respiratory system, attenuates the impact of massive brain damage on gas-exchange, respiratory mechanics, lung histology and whole genome alterations compared with high (12 milliliters per kilogram ideal body weight) VT and low positive end-expiratory pressure ventilation (HVT/LPEEP). METHODS: In total, 28 adult male Wistar rats were randomly assigned to one of four groups: 1) no brain damage (NBD) with LVT/OLPEEP; 2) NBD with HVT/LPEEP; 3) brain damage (BD) with LVT/OLPEEP; and 4) BD with HVT/LPEEP. All animals were mechanically ventilated for six hours. Brain damage was induced by an inflated balloon catheter into the epidural space. Hemodynamics was recorded and blood gas analysis was performed hourly. At the end of the experiment, respiratory system mechanics and lung histology were analyzed. Genome wide gene expression profiling and subsequent confirmatory quantitative polymerase chain reaction (qPCR) for selected genes were performed. RESULTS: In NBD, both LVT/OLPEEP and HVT/LPEEP did not affect arterial blood gases, as well as whole genome expression changes and real-time qPCR. In BD, LVT/OLPEEP, compared to HVT/LPEEP, improved oxygenation, reduced lung damage according to histology, genome analysis and real-time qPCR with decreased interleukin 6 (IL-6), cytokine-induced neutrophil chemoattractant 1 (CINC)-1 and angiopoietin-4 expressions. LVT/OLPEEP compared to HVT/LPEEP improved overall survival. CONCLUSIONS: In BD, LVT/OLPEEP minimizes lung morpho-functional changes and inflammation compared to HVT/LPEEP

Effects of mechanical ventilation on gene expression profiles in renal allografts from brain dead rats

Pathophysiological changes of brain death (BD) are impairing distal organ function and harming potential renal allografts. Whether ventilation strategies influence the quality of renal allografts from BD donors has not been thoroughly studied. 28 adult male Wistar rats were randomly assigned to four groups: 1) no brain death (NBD) with low tidal volume/low positive endexpiratory pressure (PEEP) titrated to minimal static elastance of the respiratory system (LVT/OLPEEP); 2) NBD with high tidal volume/low PEEP (HVT/LPEEP); 3) brain death (BD) with LVT/OLPEEP; and 4) BD with HVT/LPEEP. We hypothesized that HVT/LPEEP in BD leads to increased interleukin 6 (IL-6) gene expression and impairs potential renal allografts after six hours of mechanical ventilation. We assessed inflammatory cytokines in serum, genome wide gene expression profiles and quantitative PCR (qPCR) in kidney tissue. The influence of BD on renal gene-expression profiles was greater than the influence of the ventilation strategy. In BD, LVT ventilation did not influence the inflammatory parameters or kidney function in our experimental model

S-Adenosylhomocysteine Is a Useful Metabolic Factor in the Early Prediction of Septic Disease Progression and Death in Critically Ill Patients: A Prospective Cohort Study

A common final pathway of pathogenetic mechanisms in septic organ dysfunction and death is a lack or non-utilization of oxygen. Plasma concentrations of lactate serve as surrogates for the oxygen-deficiency-induced imbalance between energy supply and demand. As S-adenosylhomocysteine (SAH) was shown to reflect tissue hypoxia, we compared the ability of SAH versus lactate to predict the progression of inflammatory and septic disease to septic organ dysfunction and death. Using univariate and multiple logistic regression, we found that SAH but not lactate, taken upon patients’ inclusion in the study close to ICU admission, significantly and independently contributed to the prediction of disease progression and death. Due to the stronger increase in SAH in relation to S-adenosylmethionine (SAM), the ratio of SAM to SAH, representing methylation potential, was significantly decreased in patients with septic organ dysfunction and non-survivors compared with SIRS/sepsis patients (2.8 (IQR 2.3–3.9) vs. 8.8 (4.9–13.8); p = 0.003) or survivors (4.9 (2.8–9.5) vs. 8.9 (5.1–14.3); p = 0.026), respectively. Thus, SAH appears to be a better contributor to the prediction of septic organ dysfunction and death than lactate in critically ill patients. As SAH is a potent inhibitor of SAM-dependent methyltransferases involved in numerous vital biochemical processes, the impairment of the SAM-to-SAH ratio in severely critically ill septic patients and non-survivors warrants further studies on the pathogenetic role of SAH in septic multiple organ failure