Comparing the effects and compliance between volume-assured and pressure support non-invasive ventilation in patients with chronic respiratory failure.

INTRODUCTION: Standard bi-level non-invasive ventilation with fixed-level pressure support (PS) delivery may not maintain ventilation during the changes in pulmonary mechanics that occur throughout day and night, so average volume-assured pressure support (AVAPS) modes that target a preset volume by adjustment of PS may be effective. OBJECTIVE: Our meta-analysis wants to compare AVAPS and pressure support non-invasive ventilation (PS-NIV) regarding arterial blood gases (ABGs), sleep efficiency and compliance. METHOD: Relevant publications indexed in PubMed, Cochrane Library, Embase, Web of Science, Wanfang Data, China National Knowledge Infrastructure and VIPI were identified. Appropriate articles identified from the reference lists of the above searches were also reviewed. We included randomized controlled trials involved the use of AVAPS and PS-NIV ventilation for chronic respiratory failure. Each included study weighted mean differences, and 95% confidence intervals (CI) were calculated for continuous outcomes. Statistical heterogeneity was assessed using the I2 value ≤ 50% were considered as no statistical heterogeneity and used fixed effects model. Otherwise, a random effects model was used. RESULTS: Eight trials were eligible. No significant difference was observed between AVAPS and PS-NIV groups to compare PaCO2 (OR -0.97, CI-2.54-0.61, P = 0.23) and PaO2 (OR -1.81, CI-4.29-0.67, P = 0.15) in ABGs. There was no significant difference between the two groups with sleep efficiency (OR -3.31, CI-7.58-0.95, P = 0.13) and visual analog scale (OR 0.32, CI-6.97-7.61, P = 0.93). CONCLUSIONS: The evidence shows there is no significant difference in clinical outcomes when comparing AVAPS and PS-NIV used for chronic respiratory failure patients.

Tapered Cuff versus Conventional Cuff for Ventilator-Associated Pneumonia in Ventilated Patients: A Meta-Analysis of Randomized Controlled Trials.

Background: Microaspiration of secretions around the tracheal cuff is a multifactorial process. Tracheal cuff shape might take a major part in its occurrence. The rationale for producing a taper-shaped cuff is established on the assumption that compared to a conventional cuff with a single fixed diameter, a continuum of minimum-to-maximum diameter sections might better fit the tracheal walls. Objectives: The primary objective of this meta-analysis was to compare ventilator-associated pneumonia (VAP) between tapered-cuff intubation and conventional-cuff intubation. The secondary objective was to compare intensive care unit (ICU) mortality between tapered-cuff intubation and conventional-cuff intubation. Methods: We searched the Cochrane Library, Embase, MEDLINE database through the PubMed search engine, and CINAHL from inception to April 2018. Randomized trials comparing VAP and ICU mortality between tapered-cuff intubation and conventional-cuff intubation in intubated adults were included. Two review authors assessed study quality and abstracted databasing on prespecified criteria independently. Results: We pooled summary estimates from 5 trials evaluating tapered-cuff involving 774 participants. Compared to VAP, no statistically significant difference was observed between the tapered-cuff and conventional-cuff groups (OR 0.82, CI 0.61-1.12, z = 1.24, and p=0.21). No statistically significant difference was observed between the tapered-cuff and conventional-cuff groups with ICU mortality (OR 0.77, CI 0.55-1.08, z = 1.49, and p=0.14). Conclusions: In this meta-analysis, the tapered-cuff tracheal tube may not be superior to the standard-cuff tracheal tube in reducing VAP and ICU mortality.