Purpose
Noninvasive ventilation (NIV) may facilitate withdrawal of invasive mechanical ventilation (i-MV) and shorten intensive care unit (ICU) length of stay (LOS) in hypercapnic patients, while ...data are lacking on hypoxemic patients. We aim to determine whether NIV after early extubation reduces the duration of i-MV and ICU LOS in patients recovering from hypoxemic acute respiratory failure.
Methods
Highly selected non-hypercapnic hypoxemic patients were randomly assigned to receive NIV after early or standard extubation. Co-primary end points were duration of i-MV and ICU LOS. Secondary end points were treatment failure, severe events (hemorrhagic, septic, cardiac, renal or neurologic episodes, pneumothorax or pulmonary embolism), ventilator-associated pneumonia (VAP) or tracheobronchitis (VAT), tracheotomy, percent of patients receiving sedation after study enrollment, hospital LOS, and ICU and hospital mortality.
Results
We enrolled 130 consecutive patients, 65 treatments and 65 controls. Duration of i-MV was shorter in the treatment group than for controls 4.0 (3.0–7.0) vs. 5.5 (4.0–9.0) days, respectively,
p
= 0.004, while ICU LOS was not significantly different 8.0 (6.0–12.0) vs. 9.0 (6.5–12.5) days, respectively (
p
= 0.259). Incidence of VAT or VAP (9% vs. 25%,
p
= 0.019), rate of patients requiring infusion of sedatives after enrollment (57% vs. 85%,
p
= 0.001), and hospital LOS, 20 (13–32) vs. 27(18–39) days (
p
= 0.043) were all significantly reduced in the treatment group compared with controls. There were no significant differences in ICU and hospital mortality or in the number of treatment failures, severe events, and tracheostomies.
Conclusions
In highly selected hypoxemic patients, early extubation followed by immediate NIV application reduced the days spent on invasive ventilation without affecting ICU LOS.
Summary
We thought that the rate of postoperative pulmonary complications might be higher after pressure‐controlled ventilation than after volume‐controlled ventilation. We analysed peri‐operative ...data recorded for 109,360 adults, whose lungs were mechanically ventilated during surgery at three hospitals in Massachusetts, USA. We used multivariable regression and propensity score matching. Postoperative pulmonary complications were more common after pressure‐controlled ventilation, odds ratio (95%CI) 1.29 (1.21–1.37), p < 0.001. Tidal volumes and driving pressures were more varied with pressure‐controlled ventilation compared with volume‐controlled ventilation: mean (SD) variance from the median 1.61 (1.36) ml.kg−1 vs. 1.23 (1.11) ml.kg−1, p < 0.001; and 3.91 (3.47) cmH2O vs. 3.40 (2.69) cmH2O, p < 0.001. The odds ratio (95%CI) of pulmonary complications after pressure‐controlled ventilation compared with volume‐controlled ventilation at positive end‐expiratory pressures < 5 cmH2O was 1.40 (1.26–1.55) and 1.20 (1.11–1.31) when ≥ 5 cmH2O, both p < 0.001, a relative risk ratio of 1.17 (1.03–1.33), p = 0.023. The odds ratio (95%CI) of pulmonary complications after pressure‐controlled ventilation compared with volume‐controlled ventilation at driving pressures of < 19 cmH2O was 1.37 (1.27–1.48), p < 0.001, and 1.16 (1.04–1.30) when ≥ 19 cmH2O, p = 0.011, a relative risk ratio of 1.18 (1.07–1.30), p = 0.016. Our data support volume‐controlled ventilation during surgery, particularly for patients more likely to suffer postoperative pulmonary complications.
High-flow conditioned oxygen therapy delivered through nasal cannulae and noninvasive mechanical ventilation (NIV) may reduce the need for reintubation. Among the advantages of high-flow oxygen ...therapy are comfort, availability, lower costs, and additional physiopathological mechanisms.
To test if high-flow conditioned oxygen therapy is noninferior to NIV for preventing postextubation respiratory failure and reintubation in patients at high risk of reintubation.
Multicenter randomized clinical trial in 3 intensive care units in Spain (September 2012-October 2014) including critically ill patients ready for planned extubation with at least 1 of the following high-risk factors for reintubation: older than 65 years; Acute Physiology and Chronic Health Evaluation II score higher than 12 points on extubation day; body mass index higher than 30; inadequate secretions management; difficult or prolonged weaning; more than 1 comorbidity; heart failure as primary indication for mechanical ventilation; moderate to severe chronic obstructive pulmonary disease; airway patency problems; or prolonged mechanical ventilation.
Patients were randomized to undergo either high-flow conditioned oxygen therapy or NIV for 24 hours after extubation.
Primary outcomes were reintubation and postextubation respiratory failure within 72 hours. Noninferiority margin was 10 percentage points. Secondary outcomes included respiratory infection, sepsis, and multiple organ failure, length of stay and mortality; adverse events; and time to reintubation.
Of 604 patients (mean age, 65 SD, 16 years; 388 64% men), 314 received NIV and 290 high-flow oxygen. Sixty-six patients (22.8%) in the high-flow group vs 60 (19.1%) in the NIV group were reintubation (absolute difference, -3.7%; 95% CI, -9.1% to ∞); 78 patients (26.9%) in the high-flow group vs 125 (39.8%) in the NIV group experienced postextubation respiratory failure (risk difference, 12.9%; 95% CI, 6.6% to ∞) corrected. Median time to reintubation did not significantly differ: 26.5 hours (IQR, 14-39 hours) in the high-flow group vs 21.5 hours (IQR, 10-47 hours) in the NIV group (absolute difference, -5 hours; 95% CI, -34 to 24 hours). Median postrandomization ICU length of stay was lower in the high-flow group, 3 days (IQR, 2-7) vs 4 days (IQR, 2-9; P=.048). Other secondary outcomes were similar in the 2 groups. Adverse effects requiring withdrawal of the therapy were observed in none of patients in the high-flow group vs 42.9% patients in the NIV group (P < .001).
Among high-risk adults who have undergone extubation, high-flow conditioned oxygen therapy was not inferior to NIV for preventing reintubation and postextubation respiratory failure. High-flow conditioned oxygen therapy may offer advantages for these patients.
clinicaltrials.gov Identifier: NCT01191489.
Natural ventilation nowadays has been paid great concerns due to its zero carbon emission and good performance on the human health. In engineering applications, cross ventilation driven by winds has ...been frequently restricted in building clustered cities. Instead, single-sided natural ventilation becomes an alternative mode in wind driven natural ventilation strategies for clustered urban buildings. This research has reviewed the former published researches on single-sided natural ventilation in terms of the classification, features, influence factors, investigation methodologies and evaluation indices/parameters. Existing researches on a novel ventilation mechanism of single-sided natural ventilation—“pumping ventilation” have been comprehensively reviewed, which could be a promising ventilation strategy of single-sided natural ventilation. This critical review demonstrates that single-sided ventilation has raised increasing concerns of researchers. In current and future investigations, different methodologies and other advanced technologies should be coupled together to promote the predicting capability of single-sided ventilation. This review could facilitate the fundamental researches and engineering applications of natural ventilation in modern urban buildings.
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