This systematic review produced by Corley and colleagues was published online in Cochrane Library in May 2017.
Background: A common reason for intensive care unit (ICU) admission is the need for breathing (or respiratory) support. HFNC are small plastic tubes that sit inside the nostrils and deliver a heated mix of air and oxygen at high flow rates to patients requiring breathing support. They are used frequently in the ICU, yet no clear evidence shows whether they provide patients with long-term benefits such as reduced ICU stay or improved chances of survival.
Study characteristics: The evidence is current to March 2016. We included in the review 11 studies with 1972 participants. Most participants had respiratory failure, or had just been taken off an artificial breathing machine. Included studies compared HFNC with low-flow oxygen given through face masks, through low-flow cannulae, or through devices that use mild pressure to aid oxygen delivery. We reran the search in December 2016 and will deal with any studies of interest when we update the review.
Key results: We found no evidence that HFNC reduced the rate of treatment failure or risk of death compared with low-flow oxygen devices. We found no evidence of any advantages for HFNC in terms of adverse event rates, ICU length of stay, or duration of respiratory support. We observed no differences in participants’ blood oxygen levels or carbon dioxide blood levels, and we noted that any differences in breathing rates were small and were not considered clinically important. Studies reported no differences in patient-rated measures of comfort. Only one study found evidence of less dry mouth when HFNC was used.
Quality of evidence: Most studies had reported methods inadequately, and we did not know whether risk of bias may have affected study results. We identified few eligible studies and noted some differences among participants within our included studies, particularly in reasons for requiring respiratory support. We used the GRADE system to rate the evidence for each of our outcomes, and we judged all evidence to be of low or very low quality.
Conclusion: We were not able to collect sufficient evidence from good quality studies to determine whether HFNC offer a safe and effective way of delivering respiratory support for adults in the ICU.
This paper was published by Hukins and colleagues in Internal Medicine Journal in July 2017 volume 47 number 7 addressing the limited data on outcomes of hypoxaemic respiratory failure (HRF), especially in non-intensive care unit (ICU) settings.
Aim: To assess outcomes in HRF (without multi-system disease and not requiring early intubation) of patients directly admitted to a Respiratory High-dependency Unit (R-HDU).
Methods: This is a retrospective cohort study of HRF compared to hypercapnic respiratory failure (HCRF) in a R-HDU (2007-2011). Patient characteristics (age, gender, pre-morbid status, diagnoses) and outcomes (non-invasive ventilation (NIV) use, survival, ICU admission) were assessed.
Results: There were 1207 R-HDU admissions in 2007-2011, 205 (17%) with HRF and 495 (41%) with HCRF. The proportion with HRF increased from 12.2% in 2007 to 20.1% in 2011 (P < 0.05). HRF patients were younger, more often male and had better pre-morbid performance. Compared to HCRF, HRF was more frequently associated with lung consolidation (61% vs 15%, P < 0.001), interstitial lung disease (12% vs 1%, P < 0.001) and pulmonary hypertension (7% vs 0%, P < 0.001) and less frequently with chronic obstructive pulmonary disease (24% vs 65%, P < 0.001) and obstructive sleep apnoea (8% vs 26%, P < 0.001). Fewer patients with HRF were treated with NIV (28% vs 87%, P < 0.001), but NIV was discontinued early more often (28% vs 7%, P < 0.001). A total of 18% with HRF was transferred to ICU compared to 6% with HCRF (P = 0.06). More patients with HRF died (19.5% vs 12.3%, P = 0.02). Interstitial lung disease, consolidation, shock, malignancy and poorer pre-morbid function were associated with increased mortality.
Conclusions: Initial R-HDU management is an effective option in selected HRF to reduce ICU demand, although mortality and clinical deterioration despite NIV are more common than in HCRF.
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Background: Acute respiratory failure (ARF) remains a common hazardous complication in immunocompromised patients and is associated with increased mortality rates when endotracheal intubation is needed. We aimed to evaluate the effect of early noninvasive ventilation (NIV) compared with oxygen therapy alone in this patient population.
Conclusions: The limited evidence indicates that early use of NIV could reduce short-term mortality in selected immunocompromised patients with ARF. Further studies are needed to identify in which selected patients NIV could be more beneficial, before wider application of this ventilator strategy.
Cabrini, L. et al. Critical Care Medicine. Published online: 4 August 2016
Image shows chest X-ray of a patient with ARDS.
Objective: Noninvasive ventilation is a life-saving technique increasingly used to treat acute respiratory failure. Noninvasive ventilation has been applied mostly in ICUs, but several reasons brought to an increasing application of noninvasive ventilation in ordinary wards. Few articles evaluated the outcomes of patients receiving noninvasive ventilation including long-term follow-up. The aim of the present study was to assess 1-year survival rate of patients treated with noninvasive ventilation outside the ICU for acute respiratory failure of heterogeneous causes and to identify the predictors of long-term mortality.
Patients: Consecutive patients treated with noninvasive ventilation for acute respiratory failure.
Measurements and Main Results: Two-hundred and twenty-patients were enrolled. Mortality rates at 30-day, 90-days, and 1-year follow-up were 20%, 26%, and 34%. When excluding patients with “do-not-resuscitate” status, mortality rates were 13%, 19%, and 28%. The multivariate analyses identified solid cancer, pneumonia in hematologic patients, and do-not-resuscitate status as independent predictors of mortality with postoperative acute respiratory failure associated with improved survival. The same predictors were confirmed when excluding do-not-resuscitate patients from the analyses.
Conclusions: Noninvasive ventilation applied in ordinary wards was effective, with long-term outcomes not different from those reported for ICU settings. Solid cancer, pneumonia in hematologic malignancies, and do-not-resuscitate status predicted mortality, whereas patients with postoperative acute respiratory failure had the best survival rate. Additional studies are required to evaluate noninvasive ventilation efficacy in the wards compared with ICU.
Physical rehabilitation in the intensive care unit (ICU) may improve the outcomes of patients with acute respiratory failure. This US single centre randomised controlled trial compared standardized rehabilitation therapy (SRT) to usual ICU care in acute respiratory failure. It was published in JAMA on the 28th June 2016.
Adult patients (mean age, 58 years; women, 55%) admitted to the ICU with acute respiratory failure requiring mechanical ventilation were randomized to SRT (n=150) or usual care (n=150) with 6-month follow-up. Patients in the SRT group received daily therapy until hospital discharge, consisting of passive range of motion, physical therapy, and progressive resistance exercise. The usual care group received weekday physical therapy when ordered by the clinical team.
The primary outcome was hospital length of stay (LOS) with secondary outcomes including ventilator days, ICU days and Short Physical Performance Battery (SPPB) score. Among 300 randomized patients, the median hospital LOS was 10 days (IQR, 6 to 17) for the SRT group and 10 days (IQR, 7 to 16) for the usual care group (median difference, 0 [95% CI, -1.5 to 3], P = .41). For the secondary indicators the SRT group showed a statistically significant improvement in some but not in others.
The trial concluded that amongst patients hospitalized with acute respiratory failure, SRT compared with usual care did not decrease hospital length of stay.
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