Effects of MIAVS on Early Postoperative ELWI and Respiratory Mechanics

Relationship of Extravascular Lung Water and Pulmonary Vascular Permeability to Respiratory Mechanics in Patients with COVID-19-Induced ARDS

During acute respiratory distress syndrome (ARDS), the increase in pulmonary vascular permeability and lung water induced by pulmonary inflammation may be related to altered lung compliance. A better understanding of the interactions between respiratory mechanics variables and lung water or capillary permeability would allow a more personalized monitoring and adaptation of therapies for patients with ARDS. Therefore, our main objective was to investigate the relationship between extravascular lung water (EVLW) and/or pulmonary vascular permeability index (PVPI) and respiratory mechanic variables in patients with COVID-19-induced ARDS. This is a retrospective observational study from prospectively collected data in a cohort of 107 critically ill patients with COVID-19-induced ARDS from March 2020 to May 2021. We analyzed relationships between variables using repeated measurements correlations. We found no clinically relevant correlations between EVLW and the respiratory mechanics variables (driving pressure (correlation coefficient [CI 95%]: 0.017 [-0.064; 0.098]), plateau pressure (0.123 [0.043; 0.202]), respiratory system compliance (-0.003 [-0.084; 0.079]) or positive end-expiratory pressure (0.203 [0.126; 0.278])). Similarly, there were no relevant correlations between PVPI and these same respiratory mechanics variables (0.051 [-0.131; 0.035], 0.059 [-0.022; 0.140], 0.072 [-0.090; 0.153] and 0.22 [0.141; 0.293], respectively). In a cohort of patients with COVID-19-induced ARDS, EVLW and PVPI values are independent from respiratory system compliance and driving pressure. Optimal monitoring of these patients should combine both respiratory and TPTD variables.

Benefits may not outweigh risks of low molecular weight heparin (LMWH) in early postoperative thromboprophylaxis following minimally invasive cardiac surgery: a propensity score-matched analysis

Background

Whether the benefits of early prophylactic anticoagulation by low molecular weight heparin (LMWH) would outweigh its possible harms in patients after minimally invasive cardiac surgery (MICS) remains contentious. The aims of this study were to define the incidence of venous thromboembolism (VTE) and to assess whether early prophylactic anticoagulation by LMWH postoperatively was indeed effective in reducing VTE without increasing risk of complications after MICS.

Methods

This investigation was a single-center, retrospective, propensity score-matched analysis study. A total of 473 patients underwent MICS, of whom 257 received prophylactic anticoagulation with LMWH (LMWH group) in the early postoperative period and 216 were not treated with LMWH (Control group). The main outcome measurements included the incidence of embolism events and major bleeding events, the volume of erythrocyte transfusion, the volume of drainage and the duration of drainage after MICS. In addition, the incidence of poor wound healing, the mechanical ventilation time, ICU stay time and postoperative hospitalization time were also documented.

Results

There were fewer embolic events (P=1.000) and a higher rate of major bleeding events (P=0.008) in the LMWH group than the Control group, and their magnitude and significance were maintained in the propensity matched analysis. In the matched cohorts, there was no significant difference in the total volume of red blood cell transfusion (P=0.552), assisted mechanical ventilation time (P=0.542), and the ICU stay time (P=0.166) between the two groups; while the volume of drainage (P<0.001) and the duration of drainage (P<0.001) in the LMWH group were significantly more than the Control group, and the incidence of poor wound healing (P=0.009) and the postoperative hospitalization time (P<0.001) were significantly increased in the LMWH group.

Conclusions

Early prophylactic anticoagulation with LMWH could not reduce the incidence of embolism events after MICS. Instead, it might increase postoperative major bleeding events and prolong drainage tube indwelling time and the length of hospital stay.

Minimally invasive aortic valve replacement in high risk patient groups

Minimally invasive aortic valve replacement (AVR) aims to preserve the sternal integrity and improve postoperative outcomes. In low risk patients, this technique can be achieved with comparable mortality to the conventional approach and there is evidence of possible reduction in intensive care and hospital length of stay, transfusion requirement, renal dysfunction, improved respiratory function and increased patient satisfaction. In this review, we aim to asses if these benefits can be transferred to the high risk patient groups. We therefore, discuss the available evidence for the following high risk groups: elderly patients, re-operative surgery, poor lung function, pulmonary hypertension, obesity, concomitant procedures and high risk score cohorts.