Heated humidified high-flow nasal cannula oxygen after thoracic surgery - A randomized prospective clinical pilot trial

Impact of high-flow nasal oxygen therapy on postoperative atelectasis and reintubation rate after paediatric cardiac surgery

INTRODUCTION

Airway problems emerging after congenital cardiac surgery operations may have an impact on mortality and morbidity. Recently, to improve alveolar gas exchange and reduce respiratory effort, high-flow nasal cannula (HFNC) has started to be used in paediatric cases. This study aimed to evaluate the potential effects of high-flow nasal oxygen therapy on postoperative atelectasis development and reintubation rate in paediatric cardiac surgery patients.

METHODS

This study was conducted retrospectively in term newborns and infants younger than six months of age who underwent congenital cardiac surgery operation from 1 November 2022 to 1 November 2023 and were followed in the paediatric cardiac ICU. Patients who were receiving mechanical ventilator support at least 12 hours postoperatively were evaluated for the development of postoperative atelectasis and reintubation in the first 3 days of extubation. The patients were grouped as HFNC and non-HFNC users. Demographic characteristics, surgery type, and ICU clinical follow-up data were obtained from medical records. The results were statistically evaluated.

RESULTS

A total of 40 patients who did not use HFNC in the early postoperative period and 40 patients with HFNC in the late period during the study period were included in the study. The median age was 1 month (IQR 15 days-2 months) with equal gender distribution. Among patients, 70% of them were in the neonatal age group. Reintubation rates in the first 72 hours in HFNC users and non-HFNC users were 2.5% and 12.5%, respectively (p < 0.05). The median postoperative atelectasis scores at 24, 48, and 72 hours of extubation were 2 versus 2.5 (p > 0.05), 1.5 versus 3.5 (p < 0.05), and 1 versus 3 (p < 0.05) in HFNC users and non-HFNC users, respectively.

CONCLUSION

HFNC therapy may have a positive effect on preventing atelectasis and reducing the reintubation rate in the early postoperative period.

New Insight into Laryngo-Tracheal Surgery: High-Flow Oxygen Therapy to Prevent Early Complications after Surgery

BACKGROUND

Early post-operative airway management after laryngo-tracheal surgery is crucial. Acute respiratory failure due to glottis' edema may occur, requiring reintubation. This can prolong ventilatory assistance, jeopardizing anastomosis. To date, only judicious steroid administration and fluid management are available to avoid more invasive procedures. High-flow oxygen therapy (HFOT) is a noninvasive O2 support method providing humidification, warmed air, and Positive End-Expiratory Pressure (AIRVO2). No data about HFOT use to prevent early complications after laryngo-tracheal surgery are reported in the literature.

METHODS

Between September 2020 and September 2022, 107 consecutive patients who underwent laryngo-tracheal surgery received HFOT (Group A). Data and long-term results were compared with those of 80 patients operated between September 2018 and August 2020 (Group B), when HFOT was not available. All patients were operated in a single center. No pre- or post-operative settings changed, except for HFOT introduction. We analyzed and compared the risk for "delayed" reintubation (unexpected reintubation within the first 24-48 h after extubating/laryngeal mask removal) in the two groups.

RESULTS

No patients reported HFOT-related adverse events. The control group (B) presented "delayed" reintubation in 37% (p = 0.027), intensive care unit admission in 67% (p = 0.005) and longer hospital stay (p = 0.001) compared to the HFOT group (A). The minor complications' rate was 3% in both group and overall mortality was 0%. Re-stenosis was described in 4.6% of the HFOT group, without a statistically significant difference (p = 0.7006).

CONCLUSIONS

Our study is the first to investigate HFOT use in patients undergoing laryngo-tracheal surgery, potentially representing a consistent innovation in the peri-operative management of these patients. With the limitation of a retrospective series, we would suggest HFOT use for preventing post-operative reintubation rate, possibly reducing ICU admissions and hospital stays.

The chest X-ray score baseline in predicting continuous oxygen therapy failure in low-risk aged patients after thoracic surgery

Background

Radiographic severity assessment can be instrumental in diagnosing postoperative pulmonary complications (PPCs) and guiding oxygen therapy. The radiographic assessment of lung edema (RALE) and Brixia scores correlate with disease severity, but research on low-risk elderly patients is lacking. This study aimed to assess the efficacy of two chest X-ray scores in predicting continuous oxygen therapy (COT) treatment failure in patients over 70 years of age after thoracic surgery.

Methods

From January 2019 to December 2021, we searched for patients aged 70 years and above who underwent thoracic surgery and received COT treatment, with a focus on those at low risk of respiratory complications. Bedside chest X-rays, RALE, Brixia scores, and patient data were collected. Univariate, multivariate analyses, and 1:2 matching identified risk factors. Receiver operating characteristic (ROC) curves determined score sensitivity, specificity, and predictive values.

Results

Among the 242 patients surviving to discharge, 19 (7.9%) patients experienced COT failure. COT failure correlated with esophageal cancer surgeries, thoracotomies (36.8% vs. 9%, P=0.003; 26.3% vs. 9.4%, P=0.004), and longer operation time (3.4 vs. 2.8 h, P=0.003). Surgical approach and RALE score were independent risk factors. The prediction model had an area under the curve (AUC) of 0.839 [95% confidence interval (CI), 0.740-0.938]. Brixia and RALE scores predicted COT failure with AUCs of 0.764 (95% CI, 0.650-0.878) with a cut-off value of 6.027 and 0.710 (95% CI, 0.588-0.832) with a cut-off value of 17.134, respectively, after 1:2 matching.

Conclusions

The RALE score predict the risk of COT failure in elderly, low-risk thoracic patients better than the Brixia score. This simple, cheap, and noninvasive method helps evaluate postoperative lung damage, monitor treatment response, and provide early warning for oxygen therapy escalation. Further studies are required to confirm the validity and applicability of this model in different settings and populations.

Effects of high flow nasal cannula following minimally invasive esophagectomy in ICU patients: A prospective pre-post study

BACKGROUND/PURPOSE

Patients with esophageal cancer who undergo minimally invasive esophagectomy are at risk of postoperative pulmonary complications. High-flow nasal cannula oxygen therapy delivers humidified, warmed positive airway pressure but has not been applied routinely after surgery. Here, we aimed to compare high-flow nasal cannula and conventional oxygen therapy in patients with esophageal cancer during intensive care unit hospitalization 48 h postoperatively.

METHODS

In this prospective pre- and post-intervention study, patients with esophageal cancer who underwent elective minimally invasive esophagectomy (MIE) and were extubated in the operation room and admitted to the intensive care unit postoperatively were assigned to receive either high-flow nasal cannula (HFNCO) or standard oxygen (SO) therapy. Participants in the SO group were recruited before January 2020, and those in the HFNCO group were enrolled after January 2020. The primary outcome was the difference in postoperative pulmonary complication incidence. Secondary outcomes were the occurrence of desaturation within 48 h, PaO2/FiO2 within 48 h, anastomotic leakage, length of intensive care unit and hospital stay, and mortality.

RESULTS

The standard oxygen and high-flow nasal cannula oxygen groups comprised 33 and 36 patients, respectively. Baseline characteristics were comparable between groups. In the HFNCO group, postoperative pulmonary complication incidence was significantly reduced (22.2% vs 45.5%) and PaO2/FiO2 was significantly increased. No other between-group differences were observed.

CONCLUSION

HFNCO therapy significantly reduced postoperative pulmonary complication incidence after elective MIE in patients with esophageal cancer without increasing the risk of anastomotic leakage.

Noninvasive respiratory support after extubation: a systematic review and network meta-analysis

BACKGROUND

The effect of noninvasive respiratory support (NRS), including high-flow nasal oxygen, bi-level positive airway pressure and continuous positive airway pressure (noninvasive ventilation (NIV)), for preventing and treating post-extubation respiratory failure is still unclear. Our objective was to assess the effects of NRS on post-extubation respiratory failure, defined as re-intubation secondary to post-extubation respiratory failure (primary outcome). Secondary outcomes included the incidence of ventilator-associated pneumonia (VAP), discomfort, intensive care unit (ICU) and hospital mortality, ICU and hospital length of stay (LOS), and time to re-intubation. Subgroup analyses considered "prophylactic" versus "therapeutic" NRS application and subpopulations (high-risk, low-risk, post-surgical and hypoxaemic patients).

METHODS

We undertook a systematic review and network meta-analysis (Research Registry: reviewregistry1435). PubMed, Embase, CENTRAL, Scopus and Web of Science were searched (from inception until 22 June 2022). Randomised controlled trials (RCTs) investigating the use of NRS after extubation in ICU adult patients were included.

RESULTS

32 RCTs entered the quantitative analysis (5063 patients). Compared with conventional oxygen therapy, NRS overall reduced re-intubations and VAP (moderate certainty). NIV decreased hospital mortality (moderate certainty), and hospital and ICU LOS (low and very low certainty, respectively), and increased discomfort (moderate certainty). Prophylactic NRS did not prevent extubation failure in low-risk or hypoxaemic patients.

CONCLUSION

Prophylactic NRS may reduce the rate of post-extubation respiratory failure in ICU patients.

Noninvasive respiratory support following extubation in critically ill adults: a systematic review and network meta-analysis

PURPOSE

Systematic review and network meta-analysis to investigate the efficacy of noninvasive respiratory strategies, including noninvasive positive pressure ventilation (NIPPV) and high-flow nasal cannula (HFNC), in reducing extubation failure among critically ill adults.

METHODS

We searched databases from inception through October 2021 for randomized controlled trials (RCTs) evaluating noninvasive respiratory support therapies (NIPPV, HFNC, conventional oxygen therapy, or a combination of these) following extubation in critically ill adults. Two reviewers performed screening, full text review, and extraction independently. The primary outcome of interest was reintubation. We used GRADE to rate the certainty of our findings.

RESULTS

We included 36 RCTs (6806 patients). Compared to conventional oxygen therapy, NIPPV (OR 0.65 [95% CI 0.52-0.82]) and HFNC (OR 0.63 [95% CI 0.45-0.87]) reduced reintubation (both moderate certainty). Sensitivity analyses showed that the magnitude of the effect was highest in patients with increased baseline risk of reintubation. As compared to HFNC, no difference in incidence of reintubation was seen with NIPPV (OR 1.04 [95% CI 0.78-1.38], low certainty). Compared to conventional oxygen therapy, neither NIPPV (OR 0.8 [95% CI 0.61-1.04], moderate certainty) or HFNC (OR 0.9 [95% CI 0.66-1.24], low certainty) reduced short-term mortality. Consistent findings were demonstrated across multiple subgroups, including high- and low-risk patients. These results were replicated when evaluating noninvasive strategies for prevention (prophylaxis), but not in rescue (application only after evidence of deterioration) situations.

CONCLUSIONS

Our findings suggest that both NIPPV and HFNC reduced reintubation in critically ill adults, compared to conventional oxygen therapy. NIPPV did not reduce incidence of reintubation when compared to HFNC. These findings support the preventative application of noninvasive respiratory support strategies to mitigate extubation failure in critically ill adults, but not in rescue conditions.

Routine postoperative noninvasive respiratory support and pneumonia after elective surgery: a systematic review and meta-analysis of randomised trials

BACKGROUND

Postoperative pulmonary complications, including pneumonia, are a substantial cause of morbidity. We hypothesised that routine noninvasive respiratory support was associated with a lower incidence of pneumonia after surgery.

METHODS

Systematic review and meta-analysis of RCTs comparing the routine use of continuous positive airway pressure (CPAP), noninvasive ventilation (NIV), or high-flow nasal oxygen (HFNO) against standard postoperative care in the adult population. We searched MEDLINE (PubMed), EMBASE, and CENTRAL from the start of indexing to July 27, 2021. Articles were reviewed and data extracted in duplicate, with discrepancies resolved by a senior investigator. The primary outcome was pneumonia, and the secondary outcome was postoperative pulmonary complications. We calculated risk difference (RD) with 95% confidence intervals using DerSimonian and Laird random effects models. We assessed risk of bias using the Cochrane risk of bias tool.

RESULTS

From 18 513 records, we included 38 trials consisting of 9782 patients. Pneumonia occurred in 214/4403 (4.9%) patients receiving noninvasive respiratory support compared with 216/3937 (5.5%) receiving standard care (RD -0.01 [95% confidence interval: -0.02 to 0.00]; I²=8%; P=0.23). Postoperative pulmonary complications occurred in 393/1379 (28%) patients receiving noninvasive respiratory support compared with 280/902 (31%) receiving standard care (RD -0.11 [-0.23 to 0.01]; I²=79%; P=0.07). Subgroup analyses did not identify a benefit of CPAP, NIV, or HFNO in preventing pneumonia. Tests for publication bias suggest six unreported trials.

CONCLUSION

The results of this evidence synthesis do not support the routine use of postoperative CPAP, NIV, or HFNO to prevent pneumonia after surgery in adults.

CLINICAL TRIAL REGISTRATION

PROSPERO: CRD42019156741.

ERS Clinical Practice Guidelines: High-flow nasal cannula in acute respiratory failure

BACKGROUND

High-flow nasal cannula (HFNC) has become a frequently used non-invasive form of respiratory support in acute settings, however evidence supporting its use has only recently emerged. These guidelines provide evidence-based recommendations for the use of HFNC alongside other noninvasive forms of respiratory support in adults with acute respiratory failure (ARF).

MATERIALS AND METHODOLOGY

The European Respiratory Society Task Force panel included expert clinicians and methodologists in pulmonology and intensive care medicine. The Task Force used the GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) methods to summarize evidence and develop clinical recommendations for the use of HFNC alongside conventional oxygen therapy (COT) and non-invasive ventilation (NIV) for the management of adults in acute settings with ARF.

RESULTS

The Task Force developed 8 conditional recommendations, suggesting using: 1) HFNC over COT in hypoxemic ARF, 2) HFNC over NIV in hypoxemic ARF, 3)HFNC over COT during breaks from NIV, 4) either HFNC or COT in post-operative patients at low risk of pulmonary complications, 5) either HFNC or NIV in post-operative patients at high risk of pulmonary complications, 6) HFNC over COT in non-surgical patients at low risk of extubation failure, 7) NIV over HFNC for patients at high risk of extubation failure unless there are relative or absolute contraindications to NIV, 8) trialling NIV prior to use of HFNC in patients with chronic obstructive pulmonary disease (COPD) and hypercapnic ARF.

CONCLUSIONS

HFNC is a valuable intervention in adults with ARF. These conditional recommendations can assist clinicians in choosing the most appropriate form of non-invasive respiratory support to provide to patients in different acute settings.

Management of Postoperative Hypoxemia

Hypoxemia is common in postoperative patients and is associated with prolonged hospital stays, high costs, and increased mortality. This review discusses the postoperative management of hypoxemia in regard to the use of conventional oxygen therapy, high-flow nasal cannula oxygen therapy, CPAP, and noninvasive ventilation. The recommendations made are based on the currently available evidence.

High Flow Oxygen Therapy at Two Initial Flow Settings versus Conventional Oxygen Therapy in Cardiac Surgery Patients with Postextubation Hypoxemia: A Single-Center, Unblinded, Randomized, Controlled Trial

In cardiac surgery patients with pre-extubation PaO₂/inspired oxygen fraction (FiO₂) < 200 mmHg, the possible benefits and optimal level of high-flow nasal cannula (HFNC) support are still unclear; therefore, we compared HFNC support with an initial gas flow of 60 or 40 L/min and conventional oxygen therapy. Ninety nine patients were randomly allocated (respective ratio: 1:1:1) to I = intervention group 1 (HFNC initial flow = 60 L/min, FiO₂ = 0.6), intervention group 2 (HFNC initial flow = 40 L/min, FiO₂ = 0.6), or control group (Venturi mask, FiO₂ = 0.6). The primary outcome was occurrence of treatment failure. The baseline characteristics were similar. The hazard for treatment failure was lower in intervention group 1 vs. control (hazard ratio (HR): 0.11, 95% CI: 0.03–0.34) and intervention group 2 vs. control (HR: 0.30, 95% CI: 0.12–0.77). During follow-up, the probability of peripheral oxygen saturation (SpO₂) > 92% and respiratory rate within 12–20 breaths/min was 2.4–3.9 times higher in intervention group 1 vs. the other 2 groups. There was no difference in PaO₂/FiO₂, patient comfort, intensive care unit or hospital stay, or clinical course complications or adverse events. In hypoxemic cardiac surgery patients, postextubation HFNC with an initial gas flow of 60 or 40 L/min resulted in less frequent treatment failure vs. conventional therapy. The results in terms of SpO₂/respiratory rate targets favored an initial HFNC flow of 60 L/min.

High-flow nasal cannulae for respiratory support in adult intensive care patients

BACKGROUND

High-flow nasal cannulae (HFNC) deliver high flows of blended humidified air and oxygen via wide-bore nasal cannulae and may be useful in providing respiratory support for adults experiencing acute respiratory failure, or at risk of acute respiratory failure, in the intensive care unit (ICU). This is an update of an earlier version of the review.

OBJECTIVES

To assess the effectiveness of HFNC compared to standard oxygen therapy, or non-invasive ventilation (NIV) or non-invasive positive pressure ventilation (NIPPV), for respiratory support in adults in the ICU.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, Web of Science, and the Cochrane COVID-19 Register (17 April 2020), clinical trial registers (6 April 2020) and conducted forward and backward citation searches.

SELECTION CRITERIA

We included randomized controlled studies (RCTs) with a parallel-group or cross-over design comparing HFNC use versus other types of non-invasive respiratory support (standard oxygen therapy via nasal cannulae or mask; or NIV or NIPPV which included continuous positive airway pressure and bilevel positive airway pressure) in adults admitted to the ICU.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures as expected by Cochrane.

MAIN RESULTS

We included 31 studies (22 parallel-group and nine cross-over designs) with 5136 participants; this update included 20 new studies. Twenty-one studies compared HFNC with standard oxygen therapy, and 13 compared HFNC with NIV or NIPPV; three studies included both comparisons. We found 51 ongoing studies (estimated 12,807 participants), and 19 studies awaiting classification for which we could not ascertain study eligibility information. In 18 studies, treatment was initiated after extubation. In the remaining studies, participants were not previously mechanically ventilated. HFNC versus standard oxygen therapy HFNC may lead to less treatment failure as indicated by escalation to alternative types of oxygen therapy (risk ratio (RR) 0.62, 95% confidence interval (CI) 0.45 to 0.86; 15 studies, 3044 participants; low-certainty evidence). HFNC probably makes little or no difference in mortality when compared with standard oxygen therapy (RR 0.96, 95% CI 0.82 to 1.11; 11 studies, 2673 participants; moderate-certainty evidence). HFNC probably results in little or no difference to cases of pneumonia (RR 0.72, 95% CI 0.48 to 1.09; 4 studies, 1057 participants; moderate-certainty evidence), and we were uncertain of its effect on nasal mucosa or skin trauma (RR 3.66, 95% CI 0.43 to 31.48; 2 studies, 617 participants; very low-certainty evidence). We found low-certainty evidence that HFNC may make little or no difference to the length of ICU stay according to the type of respiratory support used (MD 0.12 days, 95% CI -0.03 to 0.27; 7 studies, 1014 participants). We are uncertain whether HFNC made any difference to the ratio of partial pressure of arterial oxygen to the fraction of inspired oxygen (PaO2/FiO2) within 24 hours of treatment (MD 10.34 mmHg, 95% CI -17.31 to 38; 5 studies, 600 participants; very low-certainty evidence). We are uncertain whether HFNC made any difference to short-term comfort (MD 0.31, 95% CI -0.60 to 1.22; 4 studies, 662 participants, very low-certainty evidence), or to long-term comfort (MD 0.59, 95% CI -2.29 to 3.47; 2 studies, 445 participants, very low-certainty evidence). HFNC versus NIV or NIPPV We found no evidence of a difference between groups in treatment failure when HFNC were used post-extubation or without prior use of mechanical ventilation (RR 0.98, 95% CI 0.78 to 1.22; 5 studies, 1758 participants; low-certainty evidence), or in-hospital mortality (RR 0.92, 95% CI 0.64 to 1.31; 5 studies, 1758 participants; low-certainty evidence). We are very uncertain about the effect of using HFNC on incidence of pneumonia (RR 0.51, 95% CI 0.17 to 1.52; 3 studies, 1750 participants; very low-certainty evidence), and HFNC may result in little or no difference to barotrauma (RR 1.15, 95% CI 0.42 to 3.14; 1 study, 830 participants; low-certainty evidence). HFNC may make little or no difference to the length of ICU stay (MD -0.72 days, 95% CI -2.85 to 1.42; 2 studies, 246 participants; low-certainty evidence). The ratio of PaO2/FiO2 may be lower up to 24 hours with HFNC use (MD -58.10 mmHg, 95% CI -71.68 to -44.51; 3 studies, 1086 participants; low-certainty evidence). We are uncertain whether HFNC improved short-term comfort when measured using comfort scores (MD 1.33, 95% CI 0.74 to 1.92; 2 studies, 258 participants) and responses to questionnaires (RR 1.30, 95% CI 1.10 to 1.53; 1 study, 168 participants); evidence for short-term comfort was very low certainty. No studies reported on nasal mucosa or skin trauma.

AUTHORS' CONCLUSIONS

HFNC may lead to less treatment failure when compared to standard oxygen therapy, but probably makes little or no difference to treatment failure when compared to NIV or NIPPV. For most other review outcomes, we found no evidence of a difference in effect. However, the evidence was often of low or very low certainty. We found a large number of ongoing studies; including these in future updates could increase the certainty or may alter the direction of these effects.

Guidelines on enhanced recovery after pulmonary lobectomy

OBJECTIVE

To establish recommendations for optimisation of the management of patients undergoing pulmonary lobectomy, particularly Enhanced Recovery After Surgery (ERAS).

DESIGN

A consensus committee of 13 experts from the French Society of Anaesthesia and Intensive Care Medicine (Soci,t, franOaise d'anesth,sie et de r,animation, SFAR) and the French Society of Thoracic and Cardiovascular Surgery (Soci,t, franOaise de chirurgie thoracique et cardiovasculaire, SFCTCV) was convened. A formal conflict-of-interest policy was developed at the onset of the process and enforced throughout. The entire guidelines process was conducted independently of any industry funding. The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to guide assessment of quality of evidence.

METHODS

Five domains were defined: 1) patient pathway and patient information; 2) preoperative management and rehabilitation; 3) anaesthesia and analgesia for lobectomy; 4) surgical strategy for lobectomy; and 5) enhanced recovery after surgery. For each domain, the objective of the recommendations was to address a number of questions formulated according to the PICO model (Population, Intervention, Comparison, Outcome). An extensive literature search on these questions was carried out and analysed using the GRADE® methodology. Recommendations were formulated according to the GRADE® methodology, and were then voted by all experts according to the GRADE grid method.

RESULTS

The SFAR/SFCTCV guideline panel provided 32 recommendations on the management of patients undergoing pulmonary lobectomy. After two voting rounds and several amendments, a strong consensus was reached for 31 of the 32 recommendations and a moderate consensus was reached for the last recommendation. Seven of these recommendations present a high level of evidence (GRADE 1+), 23 have a moderate level of evidence (18 GRADE 2+ and 5 GRADE 2-), and 2 correspond to expert opinions. Finally, no recommendation was provided for 2 of the questions.

CONCLUSIONS

A strong consensus was expressed by the experts to provide recommendations to optimise the whole perioperative management of patients undergoing pulmonary lobectomy.

The role for high flow nasal cannula as a respiratory support strategy in adults: a clinical practice guideline

Purpose

High flow nasal cannula (HFNC) is a relatively recent respiratory support technique which delivers high flow, heated and humidified controlled concentration of oxygen via the nasal route. Recently, its use has increased for a variety of clinical indications. To guide clinical practice, we developed evidence-based recommendations regarding use of HFNC in various clinical settings.

Methods

We formed a guideline panel composed of clinicians, methodologists and experts in respiratory medicine. Using GRADE, the panel developed recommendations for four actionable questions.

Results

The guideline panel made a strong recommendation for HFNC in hypoxemic respiratory failure compared to conventional oxygen therapy (COT) (moderate certainty), a conditional recommendation for HFNC following extubation (moderate certainty), no recommendation regarding HFNC in the peri-intubation period (moderate certainty), and a conditional recommendation for postoperative HFNC in high risk and/or obese patients following cardiac or thoracic surgery (moderate certainty).

Conclusions

This clinical practice guideline synthesizes current best-evidence into four recommendations for HFNC use in patients with hypoxemic respiratory failure, following extubation, in the peri-intubation period, and postoperatively for bedside clinicians.

Electronic supplementary material

The online version of this article (10.1007/s00134-020-06312-y) contains supplementary material, which is available to authorized users.

Effect of high-flow nasal cannula oxygen therapy compared with conventional oxygen therapy in postoperative patients: a systematic review and meta-analysis

OBJECTIVE

To evaluate the effect of high-flow nasal cannula oxygen therapy (HFNC) versus conventional oxygen therapy (COT) on the reintubation rate, rate of escalation of respiratory support and clinical outcomes in postextubation adult surgical patients.

DESIGN

Systematic review and meta-analysis of published literature.

DATA SOURCES

PubMed, Embase, the Cochrane Library, Web of Science, China National Knowledge Index and Wan fang databases were searched up to August 2018.

ELIGIBILITY CRITERIA

Studies in postoperative adult surgical patients (≥18 years), receiving HFNC or COT applied immediately after extubation that reported reintubation, escalation of respiratory support, postoperative pulmonary complications (PPCs) and mortality were eligible for inclusion.

DATA EXTRACTION AND SYNTHESIS

The following data were extracted from the included studies: first author's name, year of publication, study population, country of origin, study design, number of patients, patients' baseline characteristics and outcomes. Associations were evaluated using risk ratio (RR) and 95% CIs.

RESULTS

This meta-analysis included 10 studies (1327 patients). HFNC significantly reduced the reintubation rate (RR 0.38, 95% CI 0.23 to 0.61, p<0.0001) and rate of escalation of respiratory support (RR 0.43, 95% CI 0.26 to 0.73, p=0.002) in postextubation surgical patients compared with COT. There were no differences in the incidence of PPCs (RR 0.87, 95% CI 0.70 to 1.08, p=0.21) or mortality (RR 0.45, 95% CI 0.16 to 1.29, p=0.14).

CONCLUSION

HFNC is associated with a significantly lower reintubation rate and rate of escalation of respiratory support compared with COT in postextubation adult surgical patients, but there is no difference in the incidence of PPCs or mortality. More well-designed, large randomised controlled trials are needed to determine the subpopulation of patients who are most likely to benefit from HFNC therapy.

The effects of high-flow nasal cannula on intubation and re-intubation in critically ill patients: a systematic review, meta-analysis and trial sequential analysis

Objective

To evaluate the efficacy of high-flow nasal cannula in the prevention of intubation and re-intubation in critically ill patients compared to conventional oxygen therapy or noninvasive ventilation.

Methods

This systematic review was performed through an electronic database search of articles published from 1966 to April 2018. The primary outcome was the need for intubation or re-intubation. The secondary outcomes were therapy escalation, mortality at the longest follow-up, hospital mortality and the need for noninvasive ventilation.

Results

Seventeen studies involving 3,978 patients were included. There was no reduction in the need for intubation or re-intubation with high-flow nasal cannula (OR 0.72; 95%CI 0.52 - 1.01; p = 0.056). There was no difference in the need for therapy escalation (OR 0.80, 95% CI 0.59 - 1.08, p = 0.144), mortality at the longest follow-up (OR 0.94; 95%CI 0.70 - 1.25; p = 0.667), hospital mortality (OR 0.84; 95%CI 0.56 - 1.26; p = 0.391) or noninvasive ventilation (OR 0.64, 95%CI 0.39 - 1.05, p = 0.075). In the trial sequential analysis, the number of events included was lower than the optimal information size with a global type I error > 0.05.

Conclusion

In the present study and setting, high-flow nasal cannula was not associated with a reduction of the need for intubation or re-intubation in critically ill patients.

Early nasal high-flow versus Venturi mask oxygen therapy after lung resection: a randomized trial

Background

Data on high-flow nasal oxygen after thoracic surgery are limited and confined to the comparison with low-flow oxygen. Different from low-flow oxygen, Venturi masks provide higher gas flow at a predetermined fraction of inspired oxygen (FiO₂). We conducted a randomized trial to determine whether preemptive high-flow nasal oxygen reduces the incidence of postoperative hypoxemia after lung resection, as compared to Venturi mask oxygen therapy.

Methods

In this single-center, randomized trial conducted in a teaching hospital in Italy, consecutive adult patients undergoing thoracotomic lung resection, who were not on long-term oxygen therapy, were randomly assigned to receive high-flow nasal or Venturi mask oxygen after extubation continuously for two postoperative days. The primary outcome was the incidence of postoperative hypoxemia (i.e., ratio of the partial pressure of arterial oxygen to FiO₂ (PaO₂/FiO₂) lower than 300 mmHg) within four postoperative days.

Results

Between September 2015 and April 2018, 96 patients were enrolled; 95 patients were analyzed (47 in high-flow group and 48 in Venturi mask group). In both groups, 38 patients (81% in the high-flow group and 79% in the Venturi mask group) developed postoperative hypoxemia, with an unadjusted odds ratio (OR) for the high-flow group of 1.11 [95% confidence interval (CI) 0.41–3] (p = 0.84). No inter-group differences were found in the degree of dyspnea nor in the proportion of patients needing oxygen therapy after treatment discontinuation (OR 1.34 [95% CI 0.60–3]), experiencing pulmonary complications (OR 1.29 [95% CI 0.51–3.25]) or requiring ventilatory support (OR 0.67 [95% CI 0.11–4.18]). Post hoc analyses revealed that PaO₂/FiO₂ during the study was not different between groups (p = 0.92), but patients receiving high-flow nasal oxygen had lower arterial pressure of carbon dioxide, with a mean inter-group difference of 2 mmHg [95% CI 0.5–3.4] (p = 0.009), and were burdened by a lower risk of postoperative hypercapnia (adjusted OR 0.18 [95% CI 0.06–0.54], p = 0.002).

Conclusions

When compared to Venturi mask after thoracotomic lung resection, preemptive high-flow nasal oxygen did not reduce the incidence of postoperative hypoxemia nor improved other analyzed outcomes. Further adequately powered investigations in this setting are warranted to establish whether high-flow nasal oxygen may yield clinical benefit on carbon dioxide clearance.

Trial registration

ClinicalTrials.gov, NCT02544477. Registered 9 September 2015.

Electronic supplementary material

The online version of this article (10.1186/s13054-019-2361-5) contains supplementary material, which is available to authorized users.

The Effect of High-Flow Nasal Oxygen Therapy on Postoperative Pulmonary Complications and Hospital Length of Stay in Postoperative Patients: A Systematic Review and Meta-Analysis

OBJECTIVE

To evaluate the effect of high-flow nasal cannula oxygen (HFNO) therapy on hospital length of stay (LOS) and postoperative pulmonary complications (PPCs) in adult postoperative patients.

DATA SOURCES

PubMed, Embase, the Cochrane Library, Web of Science of Studies, China National Knowledge Index, and Wan Fang databases were searched until July 2018.

STUDY SELECTION

Randomized controlled trials (RCTs) comparing HFNO with conventional oxygen therapy or noninvasive mechanical ventilation in adult postoperative patients were included. The primary outcomes were hospital LOS and PPCs; short-term mortality (defined as intensive care unit, hospital, or 28-day mortality) and intubation rate were the secondary outcomes.

DATA EXTRACTION

Demographic variables, high-flow oxygen therapy application, effects, and side effects were retrieved. Data were analyzed by the methods recommended by the Cochrane Collaboration. The strength of evidence was assessed by the Grading of Recommendations Assessment, Development and Evaluation. Random errors were evaluated with trial sequential analysis.

DATA SYNTHESIS

Fourteen studies (2568 patients) met the inclusion criteria and were included. Compared to the control group, the pooled effect showed that HFNO was significantly associated with a shorter hospital stay (mean difference: -0.81; 95% confidence interval [CI]: -1.34 to -0.29, P = .002), but not mortality (risk ratio [RR]: 1.0, 95% CI: 0.63 to 1.59, P = 1.0). Weak evidence of a reduction in reintubation rate (RR: 0.76, 95% CI: 0.57-1.01, P = .06) and PPC rate (RR: 0.89, 95% CI: 0.75-1.06, P = .18) with HFNO versus control group was recorded.

CONCLUSIONS

The available RCTs suggest that, among the adult postoperative patients, HFNO therapy compared to the control group significantly reduces hospital LOS.

Effect of High-Flow Nasal Oxygen vs Standard Oxygen on 28-Day Mortality in Immunocompromised Patients With Acute Respiratory Failure: The HIGH Randomized Clinical Trial

IMPORTANCE

High-flow nasal oxygen therapy is increasingly used for acute hypoxemic respiratory failure (AHRF).

OBJECTIVE

To determine whether high-flow oxygen therapy decreases mortality among immunocompromised patients with AHRF compared with standard oxygen therapy.

DESIGN, SETTING, AND PARTICIPANTS

The HIGH randomized clinical trial enrolled 776 adult immunocompromised patients with AHRF (Pao2 <60 mm Hg or Spo2 <90% on room air, or tachypnea >30/min or labored breathing or respiratory distress, and need for oxygen ≥6 L/min) at 32 intensive care units (ICUs) in France between May 19, 2016, and December 31, 2017.

INTERVENTIONS

Patients were randomized 1:1 to continuous high-flow oxygen therapy (n = 388) or to standard oxygen therapy (n = 388).

MAIN OUTCOMES AND MEASURES

The primary outcome was day-28 mortality. Secondary outcomes included intubation and mechanical ventilation by day 28, Pao2:Fio2 ratio over the 3 days after intubation, respiratory rate, ICU and hospital lengths of stay, ICU-acquired infections, and patient comfort and dyspnea.

RESULTS

Of 778 randomized patients (median age, 64 [IQR, 54-71] years; 259 [33.3%] women), 776 (99.7%) completed the trial. At randomization, median respiratory rate was 33/min (IQR, 28-39) vs 32 (IQR, 27-38) and Pao2:Fio2 was 136 (IQR, 96-187) vs 128 (IQR, 92-164) in the intervention and control groups, respectively. Median SOFA score was 6 (IQR, 4-8) in both groups. Mortality on day 28 was not significantly different between groups (35.6% vs 36.1%; difference, -0.5% [95% CI, -7.3% to +6.3%]; hazard ratio, 0.98 [95% CI, 0.77 to 1.24]; P = .94). Intubation rate was not significantly different between groups (38.7% vs 43.8%; difference, -5.1% [95% CI, -12.3% to +2.0%]). Compared with controls, patients randomized to high-flow oxygen therapy had a higher Pao2:Fio2 (150 vs 119; difference, 19.5 [95% CI, 4.4 to 34.6]) and lower respiratory rate after 6 hours (25/min vs 26/min; difference, -1.8/min [95% CI, -3.2 to -0.2]). No significant difference was observed in ICU length of stay (8 vs 6 days; difference, 0.6 [95% CI, -1.0 to +2.2]), ICU-acquired infections (10.0% vs 10.6%; difference, -0.6% [95% CI, -4.6 to +4.1]), hospital length of stay (24 vs 27 days; difference, -2 days [95% CI, -7.3 to +3.3]), or patient comfort and dyspnea scores.

CONCLUSIONS AND RELEVANCE

Among critically ill immunocompromised patients with acute respiratory failure, high-flow oxygen therapy did not significantly decrease day-28 mortality compared with standard oxygen therapy.

TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02739451.

Effect of high-flow nasal cannula oxygen therapy vs conventional oxygen therapy on adult postcardiothoracic operation: A meta-analysis

INTRODUCTION

The effect of high-flow nasal cannula (HFNC) on adult post cardiothoracic operation remains controversial. We conducted a meta-analysis of randomized controlled trials to evaluate the effect of HFNC and conventional oxygen therapy (COT) on postcardiothoracic surgery.

METHODS

A search was conducted in Embase, MEDLINE, Ovid, and Cochrane databases until December, 2017 for all the controlled study to compare HFNC with COT in adult postcardiothoracic surgery. Two authors extracted data and assessed the quality of each study independently. The meta-analysis was performed by using RevMan 5.3. The primary outcome was the rate of escalation of respiratory support rate and pulmonary complications; secondary outcome included the length of intensive care unit (ICU) stay and length of hospital stay and the rate of intubation.

RESULTS

Four studies that involved 649 patients were included in the analysis. No significant heterogeneity was found in outcome measures. Compared with COT, HFNC were associated with a significant reduction in the escalation of respiratory support (odds ratio [OR] = 0.44, 95% confidence interval [CI] = 0.29-0.66, P < .001) and pulmonary complications (OR = 0.28, 95% CI = 0.13-0.6, P = .001). There were no significant differences in the reintubation rate (OR = 0.33, 95% CI = 0.02-5.39, P = .43), length of ICU stay (weighted mean difference = 0.11; 95% CI = -0.44 -0.26, P = .14) or length of hospital stay (weighted mean difference = -0.15, 95% CI = -0.46 -0.17, P = .36) between the 2 groups. No severe complications were reported in either group.

CONCLUSION

The HFNC could reduce respiratory support and pulmonary complications, and it could be safely administered for adult postcardiothoracic surgery. Further large-scale, randomized, and controlled trials are needed to update this finding.

High-flow nasal cannulae for respiratory support in adult intensive care patients

BACKGROUND

High-flow nasal cannulae (HFNC) deliver high flows of blended humidified air and oxygen via wide-bore nasal cannulae and may be useful in providing respiratory support for adult patients experiencing acute respiratory failure in the intensive care unit (ICU).

OBJECTIVES

We evaluated studies that included participants 16 years of age and older who were admitted to the ICU and required treatment with HFNC. We assessed the safety and efficacy of HFNC compared with comparator interventions in terms of treatment failure, mortality, adverse events, duration of respiratory support, hospital and ICU length of stay, respiratory effects, patient-reported outcomes, and costs of treatment.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2016, Issue 3), MEDLINE, the Cumulative Index to Nursing and Allied Health Literature (CINAHL), Embase, Web of Science, proceedings from four conferences, and clinical trials registries; and we handsearched reference lists of relevant studies. We conducted searches from January 2000 to March 2016 and reran the searches in December 2016. We added four new studies of potential interest to a list of 'Studies awaiting classification' and will incorporate them into formal review findings during the review update.

SELECTION CRITERIA

We included randomized controlled studies with a parallel or cross-over design comparing HFNC use in adult ICU patients versus other forms of non-invasive respiratory support (low-flow oxygen via nasal cannulae or mask, continuous positive airway pressure (CPAP), and bilevel positive airway pressure (BiPAP)).

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed studies for inclusion, extracted data, and assessed risk of bias.

MAIN RESULTS

We included 11 studies with 1972 participants. Participants in six studies had respiratory failure, and in five studies required oxygen therapy after extubation. Ten studies compared HFNC versus low-flow oxygen devices; one of these also compared HFNC versus CPAP, and another compared HFNC versus BiPAP alone. Most studies reported randomization and allocation concealment inadequately and provided inconsistent details of outcome assessor blinding. We did not combine data for CPAP and BiPAP comparisons with data for low-flow oxygen devices; study data were insufficient for separate analysis of CPAP and BiPAP for most outcomes. For the primary outcomes of treatment failure (1066 participants; six studies) and mortality (755 participants; three studies), investigators found no differences between HFNC and low-flow oxygen therapies (risk ratio (RR), Mantel-Haenszel (MH), random-effects 0.79, 95% confidence interval (CI) 0.49 to 1.27; and RR, MH, random-effects 0.63, 95% CI 0.38 to 1.06, respectively). We used the GRADE approach to downgrade the certainty of this evidence to low because of study risks of bias and different participant indications. Reported adverse events included nosocomial pneumonia, oxygen desaturation, visits to general practitioner for respiratory complications, pneumothorax, acute pseudo-obstruction, cardiac dysrhythmia, septic shock, and cardiorespiratory arrest. However, single studies reported adverse events, and we could not combine these findings; one study reported fewer episodes of oxygen desaturation with HFNC but no differences in all other reported adverse events. We downgraded the certainty of evidence for adverse events to low because of limited data. Researchers noted no differences in ICU length of stay (mean difference (MD), inverse variance (IV), random-effects 0.15, 95% CI -0.03 to 0.34; four studies; 770 participants), and we downgraded quality to low because of study risks of bias and different participant indications. We found no differences in oxygenation variables: partial pressure of arterial oxygen (PaO2)/fraction of inspired oxygen (FiO2) (MD, IV, random-effects 7.31, 95% CI -23.69 to 41.31; four studies; 510 participants); PaO2 (MD, IV, random-effects 2.79, 95% CI -5.47 to 11.05; three studies; 355 participants); and oxygen saturation (SpO2) up to 24 hours (MD, IV, random-effects 0.72, 95% CI -0.73 to 2.17; four studies; 512 participants). Data from two studies showed that oxygen saturation measured after 24 hours was improved among those treated with HFNC (MD, IV, random-effects 1.28, 95% CI 0.02 to 2.55; 445 participants), but this difference was small and was not clinically significant. Along with concern about risks of bias and differences in participant indications, review authors noted a high level of unexplained statistical heterogeneity in oxygenation effect estimates, and we downgraded the quality of evidence to very low. Meta-analysis of three comparable studies showed no differences in carbon dioxide clearance among those treated with HFNC (MD, IV, random-effects -0.75, 95% CI -2.04 to 0.55; three studies; 590 participants). Two studies reported no differences in atelectasis; we did not combine these findings. Data from six studies (867 participants) comparing HFNC versus low-flow oxygen showed no differences in respiratory rates up to 24 hours according to type of oxygen delivery device (MD, IV, random-effects -1.51, 95% CI -3.36 to 0.35), and no difference after 24 hours (MD, IV, random-effects -2.71, 95% CI -7.12 to 1.70; two studies; 445 participants). Improvement in respiratory rates when HFNC was compared with CPAP or BiPAP was not clinically important (MD, IV, random-effects -0.89, 95% CI -1.74 to -0.05; two studies; 834 participants). Results showed no differences in patient-reported measures of comfort according to oxygen delivery devices in the short term (MD, IV, random-effects 0.14, 95% CI -0.65 to 0.93; three studies; 462 participants) and in the long term (MD, IV, random-effects -0.36, 95% CI -3.70 to 2.98; two studies; 445 participants); we downgraded the certainty of this evidence to low. Six studies measured dyspnoea on incomparable scales, yielding inconsistent study data. No study in this review provided data on positive end-expiratory pressure measured at the pharyngeal level, work of breathing, or cost comparisons of treatment.

AUTHORS' CONCLUSIONS

We were unable to demonstrate whether HFNC was a more effective or safe oxygen delivery device compared with other oxygenation devices in adult ICU patients. Meta-analysis could be performed for few studies for each outcome, and data for comparisons with CPAP or BiPAP were very limited. In addition, we identified some risks of bias among included studies, differences in patient groups, and high levels of statistical heterogeneity for some outcomes, leading to uncertainty regarding the results of our analysis. Consequently, evidence is insufficient to show whether HFNC provides safe and efficacious respiratory support for adult ICU patients.