Blood markers of oxidative stress predict weaning failure from mechanical ventilation

Abstract

Patients undergoing mechanical ventilation (MV) often experience respiratory muscle dysfunction, which complicates the weaning process. There is no simple means to predict or diagnose respiratory muscle dysfunction because diagnosis depends on measurements in muscle diaphragmatic fibre. As oxidative stress is a key mechanism contributing to MV-induced respiratory muscle dysfunction, the aim of this study was to determine if differences in blood measures of oxidative stress in patients who had success and failure in a spontaneous breathing trial (SBT) could be used to predict the outcome of MV. This was a prospective analysis of MV-dependent patients (≥72 hrs; n = 34) undergoing a standard weaning protocol. Clinical, laboratory and oxidative stress analyses were performed. Measurements were made on blood samples taken at three time-points: immediately before the trial, 30 min. into the trial in weaning success (WS) patients, or immediately before return to MV in weaning failure (WF) patients, and 6 hrs after the trial. We found that blood measures of oxidative stress distinguished patients who would experience WF from patients who would experience WS. Before SBT, WF patients presented higher oxidative damage in lipids and higher antioxidant levels and decreased nitric oxide concentrations. The observed differences in measures between WF and WS patients persisted throughout and after the weaning trial. In conclusion, WF may be predicted based on higher malondialdehyde, higher vitamin C and lower nitric oxide concentration in plasma.

Clinical characteristics and outcomes of mechanically ventilated patients in respiratory intensive care unit according to weaning classification

“…Fourth, low albumin can be resulted from hem dilution when fluid overload occurs. (21) However, in spite of all these previous causes of the importance of albumin level in weaning outcome, our results did not show any statistically difference between our three groups of weaning which can be explained by the low level of serum albumin in most of the studied patients of our three groups from the start. As regard liver function test (ALT, AST) was significantly high patients with simple weaning and difficult weaning this can be explained as result of inadequate oxygen uptake by the centrilobular hepatocytes resulting in necrosis.…”

Weaning attempts, cough strength and albumin are independent risk factors of reintubation in medical patients

“…Previous studies also reported that cough peak flow was a predictor of reintubation. 24 Fourth, low albumin can be resulted from hemodilution when fluid overload occurs. Patients with cough peak flow 90 L/ min had a very low reintubation rate (1.9%).…”

“…23 And systematic inflammation is a risk factor for weaning failure. 24 Fourth, low albumin can be resulted from hemodilution when fluid overload occurs. 25 And a previous study has reported that fluid overload was a risk factor for reintubation.…”

Supplementation of Lactobacillus plantarum or Macleaya cordata Extract Alleviates Oxidative Damage Induced by Weaning in the Lower Gut of Young Goats

“…The imbalance of the intestinal redox status usually restrains the capacity of eliminating ROS, resulting in oxidative damage to the intestinal epithelial cells [23,24]. In addition, MDA is one of the lipid peroxide metabolites and an essential symbol of oxidative damage, which can be enhanced with weaning stress [25,26]. In this study, the higher MDA content with less antioxidant enzymes activity in weaned young goats was expected, which suggests that early weaning can induce oxidative damage in the young goats.…”