Can non-invasive positive pressure ventilation prevent endotracheal intubation in acute lung injury/acute respiratory distress syndrome? A meta-analysis.

The role of non-invasive positive pressure ventilation (NIPPV) in acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is controversial. The aim of this study was to investigate whether NIPPV could prevent endotracheal intubation and decrease mortality rate in patients with ALI/ARDS. Randomized controlled trials (RCT) which reported endotracheal intubation and mortality rate in patients with ALI/ARDS treated by NIPPV were identified in Pubmed, Medline, Embase, Central Cochrane Controlled Trials Register, Chinese National Knowledge Infrastructure, reference lists and by manual searches. Fixed- and random-effects models were used to calculate pooled relative risks. This meta-analysis included six RCT involving 227 patients. The results showed that endotracheal intubation rate was lower in NIPPV (95% confidence interval (CI): 0.44-0.80, z = 3.44, P = 0.0006), but no significant difference was found either in intensive care unit (ICU) mortality (95% CI: 0.45-1.07, z = 1.65, P = 0.10) or in hospital mortality (95% CI: 0.17-1.58, z = 1.16, P = 0.25). Only two studies discussed the aetiology of ALI/ARDS as pulmonary or extra-pulmonary, and neither showed statistical heterogeneity (I(2) = 0%, χ(2) = 0.31, P = 0.58), nor a significant difference in endotracheal intubation rate (95% CI: 0.35-9.08, z = 0.69, P = 0.49). In conclusion, the early use of NIPPV can decrease the endotracheal intubation rate in patients with ALI/ARDS, but does not change the mortality of these patients.

Emulsified isoflurane protects rat heart in situ after regional ischemia and reperfusion.

Volatile anesthetic postconditioning reduces myocardial infarct size against ischemia/reperfusion (I/R) injury. We tested the hypothesis that emulsified isoflurane (EIso) administrated after ischemia exerts cardioprotection in a rat model of myocardial I/R. Male SD rats underwent 30-min coronary occlusion followed by 3-h reperfusion except for sham rats. All vehicles were administrated intravenously at reperfusion onset for 30 min. In the first study, 56 rats were given saline (CON), 30% intralipid (IL) and 1, 2, 4, 8 or 16 mL/kg EIso for infarct size measurement. In a second study, 32 rats were randomized to four groups and administrated saline in sham (sham) and control (CON) groups, 30% intralipid in IL group and 2 mL/kg emulsified isoflurane in EIso group. Cardiomyocytic enzyme activity was determined. Myocardial mitochondria and cytosol were isolated to determine mitochondrial energy metabolism, cytochrome c release, mitochondrial membrane potential (ΔΨm) and opening of the mitochondrial permeability transition pore (mPTP). Morphologic changes in mitochondria were observed by transmission electron microscopy. Compared with CON and IL, 2, 4 and 8 mL/kg EIso limited infarct size (P < 0.01). Serum levels of cardiac enzyme leakage were reduced in EIso-treated hearts compared with CON (P < 0.01 or P < 0.05). EIso preserved the ultrastructure of mitochondria, protected against mPTP opening, decreased cytochrome c release and preserved ATP production and ΔΨm . In conclusion, EIso is effective in reducing infarct size and in preserving mitochondrial function after ischemia and reperfusion injury.

Efficacy and safety of sildenafil treatment in pulmonary arterial hypertension: a systematic review.

BACKGROUND: To evaluate the safety and efficacy of using sildenafil for ≥ 12 weeks to treat pulmonary arterial hypertension (PAH). METHODS: Randomized controlled trials (RCTs) of sildenafil therapy in patients with PAH published through May 2013 were identified by searching PubMed, the Cochrane Library, Embase, relevant websites, and reference lists of relevant studies. Two reviewers independently assessed the quality of the trials and extracted information. RESULTS: Meta-analysis was carried out with subsets of 4 trials involving 545 patients. Sildenafil therapy significantly reduced clinical worsening of PAH compared to placebo (RR 0.39, 95% CI 0.21-0.69) and improved the 6-min walk distance (MD 31.3 m, 95% CI 18.01-44.67), WHO functional class, hemodynamic variables and health-related quality of life (HRQoL). Sildenafil did not, however, improve all-cause mortality (RR 0.29, 95% CI 0.02-4.94) or Borg dyspnea score relative to placebo, nor did it significantly affect the incidence of serious adverse events. In fact, sildenafil was associated with higher total incidence of adverse events, but these additional events were mild to moderate in severity and were tolerable. CONCLUSIONS: Sildenafil therapy lasting ≥ 12 weeks improves multiple clinical and hemodynamic outcomes in patients with PAH, but it appears to have no effect on mortality or serious adverse events. The long-term efficacy and safety of sildenafil therapy in PAH requires further study based on large and well-designed RCTs.