Lung-protective mechanical ventilation for patients undergoing abdominal laparoscopic surgeries: a randomized controlled trial

Background Pneumoperitoneum and Trendelenburg position in laparoscopic surgeries could contribute to postoperative pulmonary dysfunction. In recent years, intraoperative lung-protective mechanical ventilation (LPV) has been reportedly able to attenuate ventilator-induced lung injuries (VILI). Our objectives were to test the hypothesis that LPV could improve intraoperative oxygenation function, pulmonary mechanics and early postoperative atelectasis in laparoscopic surgeries. Methods In this randomized controlled clinical trial, 62 patients indicated for elective abdominal laparoscopic surgeries with an expected duration of greater than 2 h were randomly assigned to receive either lung-protective ventilation (LPV) with a tidal volume (Vt) of 7 ml kg− 1 ideal body weight (IBW), 10 cmH2O positive end-expiratory pressure (PEEP) combined with regular recruitment maneuvers (RMs) or conventional ventilation (CV) with a Vt of 10 ml kg− 1 IBW, 0 cmH2O in PEEP and no RMs. The primary endpoints were the changes in the ratio of PaO2 to FiO2 (P/F). The secondary endpoints were the differences between the two groups in PaO2, alveolar-arterial oxygen gradient (A-aO2), intraoperative pulmonary mechanics and the incidence of atelectasis detected on chest x-ray on the first postoperative day. Results In comparison to CV group, the intraoperative P/F and PaO2 in LPV group were significantly higher while the intraoperative A-aO2 was clearly lower. Cdyn and Cstat at all the intraoperative time points in LPV group were significantly higher compared to CV group (p < 0.05). There were no differences in the incidence of atelectasis on day one after surgery between the two groups. Conclusions Lung protective mechanical ventilation significantly improved intraoperative pulmonary oxygenation function and pulmonary compliance in patients experiencing various abdominal laparoscopic surgeries, but it could not ameliorate early postoperative atelectasis and oxygenation function on the first day after surgery. Trial registration https://www.clinicaltrials.gov/identifier: NCT04546932 (09/05/2020).

Brain injury after 50 h of lung-protective mechanical ventilation in a preclinical model

Mechanical ventilation is the cornerstone of the Intensive Care Unit. However, it has been associated with many negative consequences. Recently, ventilator-induced brain injury has been reported in rodents under injurious ventilation settings. Our group wanted to explore the extent of brain injury after 50 h of mechanical ventilation, sedation and physical immobility, quantifying hippocampal apoptosis and inflammation, in a normal-lung porcine study. After 50 h of lung-protective mechanical ventilation, sedation and immobility, greater levels of hippocampal apoptosis and neuroinflammation were clearly observed in the mechanically ventilated group, in comparison to a never-ventilated group. Markers in the serum for astrocyte damage and neuronal damage were also higher in the mechanically ventilated group. Therefore, our study demonstrated that considerable hippocampal insult can be observed after 50 h of lung-protective mechanical ventilation, sedation and physical immobility.

Non-Invasive Mechanical Ventilation in Children with Previous Unsuccessful Weaning from Respiratory Therapy

The objective of the research was to establish the impact of diaphragm-protective mechanical ventilation on the rate of successful weaning from invasive and non-invasive mechanical ventilation in children with acute respiratory failure. Materials and Methods. We conducted a prospective, observational cohort study. Seventy-eight patients were randomly divided into 2 groups: patients of Group I received lung-protective mechanical ventilation; patients of Group II received diaphragm-protective + lung-protective mechanical ventilation. For age-specific data analysis, patients were divided into age subgroups: the 1st subgroup included children being 1 to 12 months old; the 2nd age subgroup comprised children being 12 to 36 months old. We started respiratory support in both groups with invasive mechanical ventilation and when patients met the criteria, we weaned them. We confirmed successful weaning, when patients had no need to be mechanically ventilated within next 48 hours, otherwise, they were intubated again. Before the second trial to wean, patients in Group I were simply extubated, while patients in Group II received non-invasive mechanical ventilation. The primary endpoint was the rate of successful weaning from mechanical ventilation in the first trial. The secondary outcomes were complications, namely reintubation rate, tracheostomy rate and death. Results. We found a significant difference in the primary outcome for the 1st age subgroup: there were 72.4% in Group I vs. 52.6% in Group II successfully weaned patients (p=0.04). No significant difference in the primary outcome was observed in the 2nd age subgroup: there were 80% in Group I vs. 82.3% in Group II successfully weaned patients (p=0.78). There were significant differences in the secondary outcomes between groups in the 1st age subgroup, namely reintubation rate was seen in 9.1% patients of Group I vs. 36.8% patients of Group II (p=0.05); death happened in 18.2% cases in Group I vs. no cases in Group II (p=0.01). There were no differences in tracheostomy rate in the 1st age subgroup and there were no differences in the secondary outcomes between groups in 2nd age subgroup. Conclusions. Diaphragm-protective mechanical ventilation significantly reduced the incidence of successful weaning from invasive mechanical ventilation; however, it increased the incidence of successful weaning from non-invasive mechanical ventilation, and, significantly decreased the mortality rate in the 1st age subgroup, while in the 2nd age subgroup, it had no impact on the incidence of successful weaning from invasive mechanical ventilation and mortality rate.