High-flow nasal cannula therapy versus conventional oxygen therapy for adult patients after cardiac surgery: A systemic review and meta-analysis

BACKGROUND

Oxygen therapy constitutes a crucial element of post-cardiac operative care. The study assessed the effectiveness of high-flow nasal cannula (HFNC) in comparison to conventional oxygen therapy (COT).

OBJECTIVES

The aim of the study was to assess the effectiveness of HFNC in comparison to COT for adult patients following cardiac surgery.

METHODS

We conducted a comprehensive search of Embase, PubMed, Scopus, Cochrane Library, and Web of Science databases from inception until April 18, 2023, to identify randomized controlled trials (RCTs) and crossover studies that compared the efficacy of HFNC with COT in adult patients following cardiac surgery.

RESULTS

The meta-analysis included nine studies, consisting of eight RCTs and one crossover study. Compared with COT, HFNC could reduce the need for escalation of respiratory support (RR 0.67, 95% CI: 0.48 to 0.93, P = 0.02), decrease arterial partial pressure of carbon dioxide (PaCO2) levels (MD -3.14, 95% CI: -4.90 to -1.39, P<0.001), and increase forced expiratory volume in 1 second (FEV1) levels (MD 0.08, 95% CI: 0.02 to 0.15, P = 0.02). There was no significant difference between the HFNC and COT groups in terms of mortality, intubation rate, respiratory rate, heart rate, intensive care unit and hospital length of stay, arterial partial pressure of oxygen (PaO2), forced vital capacity, and complications of atrial fibrillation and delirium.

CONCLUSION

Compared with COT, HFNC could decrease the need for escalation of respiratory support, lower PaCO2 levels, and elevate FEV1 levels in patients following cardiac surgery.

Effects of non-invasive respiratory support in post-operative patients: a systematic review and network meta-analysis

BACKGROUND

Re-intubation secondary to post-extubation respiratory failure in post-operative patients is associated with increased patient morbidity and mortality. Non-invasive respiratory support (NRS) alternative to conventional oxygen therapy (COT), i.e., high-flow nasal oxygen, continuous positive airway pressure, and non-invasive ventilation (NIV), has been proposed to prevent or treat post-extubation respiratory failure. Aim of the present study is assessing the effects of NRS application, compared to COT, on the re-intubation rate (primary outcome), and time to re-intubation, incidence of nosocomial pneumonia, patient discomfort, intensive care unit (ICU) and hospital length of stay, and mortality (secondary outcomes) in adult patients extubated after surgery.

METHODS

A systematic review and network meta-analysis of randomized and non-randomized controlled trials. A search from Medline, Embase, Scopus, Cochrane Central Register of Controlled Trials, and Web of Science from inception until February 2, 2024 was performed.

RESULTS

Thirty-three studies (11,292 patients) were included. Among all NRS modalities, only NIV reduced the re-intubation rate, compared to COT (odds ratio 0.49, 95% confidence interval 0.28; 0.87, p = 0.015, I2 = 60.5%, low certainty of evidence). In particular, this effect was observed in patients receiving NIV for treatment, while not for prevention, of post-extubation respiratory failure, and in patients at high, while not low, risk of post-extubation respiratory failure. NIV reduced the rate of nosocomial pneumonia, ICU length of stay, and ICU, hospital, and long-term mortality, while not worsening patient discomfort.

CONCLUSIONS

In post-operative patients receiving NRS after extubation, NIV reduced the rate of re-intubation, compared to COT, when used for treatment of post-extubation respiratory failure and in patients at high risk of post-extubation respiratory failure.

Liberation from mechanical ventilation in critically ill patients: Korean Society of Critical Care Medicine Clinical Practice Guidelines

BACKGROUND

Successful liberation from mechanical ventilation is one of the most crucial processes in critical care because it is the first step by which a respiratory failure patient begins to transition out of the intensive care unit and return to their own life. Therefore, when devising appropriate strategies for removing mechanical ventilation, it is essential to consider not only the individual experiences of healthcare professionals, but also scientific and systematic approaches. Recently, numerous studies have investigated methods and tools for identifying when mechanically ventilated patients are ready to breathe on their own. The Korean Society of Critical Care Medicine therefore provides these recommendations to clinicians about liberation from the ventilator.

METHODS

Meta-analyses and comprehensive syntheses were used to thoroughly review, compile, and summarize the complete body of relevant evidence. All studies were meticulously assessed using the Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) method, and the outcomes were presented succinctly as evidence profiles. Those evidence syntheses were discussed by a multidisciplinary committee of experts in mechanical ventilation, who then developed and approved recommendations.

RESULTS

Recommendations for nine PICO (population, intervention, comparator, and outcome) questions about ventilator liberation are presented in this document. This guideline includes seven conditional recommendations, one expert consensus recommendation, and one conditional deferred recommendation.

CONCLUSIONS

We developed these clinical guidelines for mechanical ventilation liberation to provide meaningful recommendations. These guidelines reflect the best treatment for patients seeking liberation from mechanical ventilation.

Impact of different oxygen therapy strategies on the risk of endotracheal reintubation in mechanically ventilated patients: A systematic review and meta-analysis

BACKGROUND

Mechanical ventilation (MV) is a crucial intervention for the support of patients with acute and severe respiratory failure in modern intensive care medicine. However, the mechanical forces resulting from the interplay between the ventilator and the respiratory system may cause pulmonary injury.

OBJECTIVE

To compare the effects of high-flow nasal cannula (HFNC) therapy and other oxygen therapy modalities on the risk of endotracheal reintubation in mechanically ventilated patients after extubation in the intensive care unit (ICU).

METHODS

An electronic search was carried out across various databases including PubMed, Embase, Ovid, Medline, Cochrane Library, Embase, VIP, and Wanfang. The objective of this search was to locate prospective randomized controlled trials that examined the effects of multiple oxygen therapy approaches on the incidence of reintubation in patients in the ICU after undergoing mechanical ventilation. The meta package in R language was used to analyze parameters adopted by the included studies such as reintubation rate, mortality rate, and length of hospital stay.

RESULTS

This study enrolled 22 articles, involving 4,160 participants, with 2,061 in the study group and 2,099 in the control group. Among these, 20 articles presented data on the reintubation rate of the patients included with an odds ratio (OR) of 0.90 (95% CI: 0.74, 1.09) for HFNC and an OR of 1.77 (95% CI: 0.93, 3.38) for HFNC in the chronic obstructive pulmonary disease (COPD) subgroup. Moreover, 10 articles assessed the incidence of respiratory failure after extubation, revealing an OR for HFNC was 0.68 (95% CI: 0.55, 0.84) using a fixed-effects model. Nine articles addressed ICU mortality, while 13 pieces of literature examined hospital mortality. HFNC showed no significant impact on either ICU mortality or hospital mortality.

CONCLUSION

HFNC therapy markedly reduces the incidence of respiratory failure in mechanically ventilated patients following extubation in the ICU. Furthermore, it specifically reduces the risk of reintubation in patients diagnosed with COPD.

Effect of a pre-emptive 2-hour session of high-flow nasal oxygen on postoperative oxygenation after major gynaecologic surgery: a randomised clinical trial

BACKGROUND

We aimed at determining whether a 2-h session of high-flow nasal oxygen (HFNO) immediately after extubation improves oxygen exchange after major gynaecological surgery in the Trendelenburg position in adult female patients.

METHODS

In this single-centre, open-label, randomised trial, patients who underwent major gynaecological surgery were randomised to HFNO or conventional oxygen treatment with a Venturi mask. The primary outcome was the Pao2/FiO2 ratio after 2 h of treatment. Secondary outcomes included lung ultrasound score, diaphragm thickening fraction, dyspnoea, ventilatory frequency, Paco2, the percentage of patients with impaired gas exchange (Pao2/FiO2 ≤40 kPa) after 2 h of treatment, and postoperative pulmonary complications at 30 days.

RESULTS

A total of 83 patients were included (42 in the HFNO group and 41 in the conventional treatment group). After 2 h of treatment, median (inter-quartile range) Pao2/FiO2 was 52.9 (47.9-65.2) kPa in the HFNO group and 45.7 (36.4 -55.9) kPa in the conventional treatment group (mean difference 8.7 kPa [95% CI: 3.4 to 13.9], P=0.003). The lung ultrasound score was lower in the HFNO group than in the conventional treatment group (9 [6-10] vs 12 [10-14], P<0.001), mostly because of the difference of the score in dorsal areas (7 [6-8] vs 10 [9-10], P<0.001). The percentage of patients with impaired gas exchange was lower in the HFNO group than in the conventional treatment group (5% vs 37%, P<0.001). All other secondary outcomes were not different between groups.

CONCLUSIONS

In patients who underwent major gynaecological surgery, a pre-emptive 2-h session of HFNO after extubation improved postoperative oxygen exchange and reduced atelectasis compared with a conventional oxygen treatment strategy.

CLINICAL TRIAL REGISTRATION

NCT04566419.

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.

Prophylactic noninvasive respiratory support in the immediate postoperative period after cardiac surgery - a systematic review and network meta-analysis

BACKGROUND

Noninvasive respiratory support has been increasingly applied in the immediate postoperative period to prevent postoperative pulmonary complications (PPCs). However, the optimal approach remains uncertain. We sought to evaluate the comparative effectiveness of various noninvasive respiratory strategies used in the immediate postoperative period after cardiac surgery.

METHODS

We conducted a frequentist random-effect network meta-analysis (NMA) of randomized controlled trials (RCTs) comparing the prophylactic use of noninvasive ventilation (NIV), continuous positive airway pressure (CPAP), high flow nasal cannula (HFNC), or postoperative usual care (PUC) in the immediate postoperative period after cardiac surgery. Databases were systematically searched through September 28, 2022. Study selection, data extraction, and quality assessment were performed in duplicate. The primary outcome was the incidence of PPCs.

RESULTS

Sixteen RCTs enrolling 3011 patients were included. Compared with PUC, NIV significantly reduced the incidence of PPCs [relative risk (RR) 0.67, 95% confidence interval (CI): 0.49 to 0.93; absolute risk reduction (ARR) 7.6%, 95% CI: 1.6-11.8%; low certainty] and the incidence of atelectasis (RR 0.65, 95% CI: 0.45 to 0.93; ARR 19.3%, 95% CI: 3.9-30.4%; moderate certainty); however, prophylactic NIV was not associated with a decreased reintubation rate (RR 0.82, 95% CI: 0.29 to 2.34; low certainty) or reduced short-term mortality (RR 0.64, 95% CI: 0.16 to 2.52; very low certainty). As compared to PUC, the preventive use of CPAP (RR 0.85, 95% CI: 0.60 to 1.20; very low certainty) or HFNC (RR 0.74, 95% CI: 0.46 to 1.20; low certainty) had no significant beneficial effect on the incidence of PPCs, despite exhibiting a downward trend. Based on the surface under the cumulative ranking curve, the highest-ranked treatment for reducing the incidence of PPCs was NIV (83.0%), followed by HFNC (62.5%), CPAP (44.3%), and PUC (10.2%).

CONCLUSIONS

Current evidence suggest that the prophylactic use of NIV in the immediate postoperative period is probably the most effective noninvasive respiratory approach to prevent PPCs in patients undergoing cardiac surgery. Given the overall low certainty of the evidence, further high-quality research is warranted to better understand the relative benefits of each noninvasive ventilatory support.

CLINICAL TRIAL REGISTRATION

PROSPERO, https://www.crd.york.ac.uk/prospero/ , registry number: CRD42022303904.

High-flow nasal oxygen vs. standard oxygen therapy for patients undergoing transcatheter aortic valve replacement with conscious sedation: a randomised controlled trial

BACKGROUND

Minimally invasive surgery is becoming more common and transfemoral transcatheter aortic valve replacement is offered to older patients with multiple comorbidities. Sternotomy is not required but patients must lie flat and still for up to 2-3 h. This procedure is increasingly being performed under conscious sedation with supplementary oxygen, but hypoxia and agitation are commonly observed.

METHODS

In this randomised controlled trial, we hypothesised that high-flow nasal oxygen would provide superior oxygenation as compared with our standard practice, 2 l min^-1 oxygen by dry nasal specs. This was administered using the Optiflow THRIVE Nasal High Flow delivery system (Fisher and Paykel, Auckland, New Zealand) at a flow rate of 50 l min^-1 and FiO₂ 0.3. The primary endpoint was the change in arterial partial pressure of oxygen (pO₂) during the procedure. Secondary outcomes included the incidence of oxygen desaturation, airway interventions, the number of times the patient reached for the oxygen delivery device, incidence of cerebral desaturation, peri-operative oxygen therapy duration, hospital length of stay and patient satisfaction scores.

RESULTS

A total of 72 patients were recruited. There was no difference in change in pO₂ from baseline using high-flow compared with standard oxygen therapy: median [IQR] increase from 12.10 (10.05-15.22 [7.2-29.8]) to 13.69 (10.85-18.38 [8.5-32.3]) kPa vs. decrease from 15.45 (12.17-19.33 [9.2-22.8]) to 14.20 (11.80-19.40 [9.7-35.1]) kPa, respectively. The percentage change in pO2 after 30 min was also not significantly different between the two groups (p = 0.171). There was a lower incidence of oxygen desaturation in the high-flow group (p = 0.027). Patients in the high-flow group assigned a significantly higher comfort score to their treatment (p ≤ 0.001).

CONCLUSION

This study has demonstrated that high flow, compared with standard oxygen therapy, does not improve arterial oxygenation over the course of the procedure. There are suggestions that it may improve the secondary outcomes studied.

TRIAL REGISTRATION

International Standard Randomised Controlled Trial Number (ISRCTN) 13,804,861. Registered on 15 April 2019. https://doi.org/10.1186/ISRCTN13804861.

[The perioperative role of high-flow cannula oxygen (HFNO)]

High-flow nasal cannula oxygen (HFNO) is commonly used during the perioperative period. Its numerous physiological benefits, satisfactory tolerance and ease of use have led to its widespread application in intensive care and post-anesthesia care units. HFNO is also used in the operating theater in multiple indications: as oxygen supplementation (associated with pressurization) prior to orotracheal intubation; in digestive and bronchial endoscopies, especially in patients at risk of hypoxemia; and in intraoperative surgery requiring spontaneous ventilation (ENT, thoracic surgery…). During the postoperative period, HFNO can be used in a curative strategy for respiratory failure or in a prophylactic strategy to prevent reintubation. In a curative approach, HFNO seems of interest following cardiac or thoracic surgery but has not been evaluated in respiratory failure subsequent to abdominal surgery, in which case noninvasive ventilation remains the gold standard. The risk of respiratory complications depends on type of surgery and on patient comorbidities. As prophylaxis, HFNO is currently preferred to conventional oxygen therapy after cardiac or thoracic surgery, especially in patients at high risk of respiratory complications. For the clinician, it is important to acknowledge the limits of HFNO and to closely monitor patients receiving HFNO, the objective being to avoid delays in intubation that could lead to increased mortality.

High-Flow Nasal Oxygenation and Its Applicability in COVID Patients

High-flow nasal oxygenation (HFNO) is a type of oxygen therapy that provides humidified and heated oxygen through a nasal cannula at much higher flow rates than standard oxygen therapy, while also allowing control over the fraction of inspired oxygen (FIO₂). Compared to standard oxygen therapy, it is much more comfortable for the patient and seems to alleviate most of the problems associated with standard oxygen therapy, such as dry nose, dry throat and nasal pain. It also provides a variety of benefits that can reduce the incidence of escalating treatment and initiating mechanical ventilation in COVID patients with acute hypoxemic respiratory failure (AHRF). This article provides an overview of HFNO and its current applications in COVID patients during the pandemic.

The short-term efficacy of high flow nasal oxygen therapy on cardiovascular surgical patients: a randomized crossover trial

Background

Oxygen therapy after extubation in the intensive care unit (ICU) is essential in order to maintain adequate oxygenation, especially in patients who have undertaken cardiovascular surgery. A Venturi mask (VM) has been routinely used as an oxygen therapy in the ICU. Recently, however, the high flow nasal cannula (HFNC) has become available, and this device can deliver up to 60 L/min of humidified oxygen. The aim of this study is to evaluate the short-term efficacy between HFNC and VM in cardiovascular surgical patients.

Methods

Forty patients who underwent cardiovascular surgery were randomized to either protocol A (HFNC followed by VM) or protocol B (VM followed by HFNC). After 60-minutes of use with either device, arterial blood gas analysis was performed, and the PaO₂/FiO₂ ratio (PFR) was calculated. Simultaneously, physiological data (respiratory rate, heart rate, mean arterial pressure, continuous cardiac index, and mixed venous oxygen saturation) were recorded. During this procedure, FiO₂ and gas flow were maintained at a fixed rate. These variables were compared by using the paired t-test, and a p value < 0.05 was considered significant. All data were expressed as mean (standard deviation).

Results

Thirty-five patients (17 from protocol A and 18 from protocol B) were enrolled, and 5 patients were excluded from analysis in accordance with the exit criteria. PaO₂ was significantly higher in the HFNC group than in the VM group [101.7 (25.9) vs. 91.8 (23.0), mean difference 9.87 (18.5), 95% confidence interval 3.5 to 16.2, p = 0.003]. Moreover, PFR was significantly higher in the HFNC group than in the VM group [265.9 (81.4) vs. 238.7 (68.5), p = 0.002]. Moreover, PaCO₂ was significantly lower in the HFNC group than in the VM group [33.8 (3.5) vs. 34.7 (2.9), p = 0.033]. The respiratory rate was significantly lower in the HFNC group than in the VM group [18 (4) vs. 21 (4), p = 0.006], and no significant differences were seen in any of the other parameters.

Conclusions

Compared to VM, HFNC ameliorated oxygenation function and decreased patients’ effort in breathing. The hemodynamic state did not differ between HFNC and VM. Therefore, HFNC can be used safely in cardiovascular surgical patients.

Trial registration

This trial was registered with the UMIN Clinical Trials Registry (ID UMIN000016572).

[Efficacy Analysis of High-flow Nasal Oxygen Therapy in Patients Accepting Single-port Video-assisted Thoracoscopic Lobectomy]

BACKGROUND

Patients who underwent lobectomy resection are prone to hypoxemia, and the vast majority present with type I respiratory failure. Thus, improvement of hypoxemia is one of the most important factors to facilitate postoperative recovery of patients. In this study, the superiority-inferiority of different oxygen inhalation methods were compared with high-flow nasal oxygen therapy (HFNO), noninvasive mechanical ventilation (NIMV) and nasal oxygen breath (NOB) in patients with hypoxemia after single-port video-assisted thoracoscopic (VATS) lobectomy, and the clinical efficacy of HFNO in these patients was further investigated.

METHODS

A total of 180 patients from the Second Affiliated Hospital of Soochow University in China with hypoxemia who accepting single-port VATS lobectomy from June 2021 to March 2022 were randomly divided into three groups (n=60), which were treated with HFNO, NIMV and NOB, respectively. The results of arterial blood gas analysis, patient's comfort score and incidence of complications were observed before, 1 h, 6 h-12 h and after use. Statistical analyses were conducted using statistical program for social sciences 25.0 (SPSS 25.0), and P<0.05 was considered as statistical significance.

RESULTS

For patients with hypoxemia after accepting single-port VATS lobectomy, HFNO was no less effective than NIMV (P=0.333), and both of whom could fast increase patients' partial pressure of oxygen/fraction of inspiration O₂ (PaO₂/FiO₂) compared to NOB (P<0.001). Besides, HFNO shows a great advantage in comfort degree and stay length (P<0.001, P=0.004), and incidence of complications were slightly lower than other groups (P=0.232). But it is worthy to note that HFNO is still slightly less effective than NIMV in patients with postoperative hypoxemia accompanied by elevated partial pressure of carbon dioxide (PaCO₂).

CONCLUSIONS

For patients with hypoxemia who accepting single-port VATS lobectomy, HFNO can be used as the first choice. However, for patients with postoperative hypoxemia accompanied by elevated PaCO₂, NIMV is still recommended to improve oxygenation.

Effect of heated humidified high-flow nasal cannula (HFNC) oxygen therapy in dyspnea patients with advanced cancer, a randomized controlled clinical trial

PURPOSE

Heated humidified high-flow nasal cannula (HFNC) oxygen therapy is one of the most important oxygen therapy methods, which are commonly applied to relieve dyspnea in advanced cancer patients. Our study aims to observe the efficacy and safety of HFNC oxygen therapy on dyspnea patients with advanced cancer and explore the clinical application.

METHODS

Sixty subjects with advanced cancer requiring oxygen therapy from a grade 3, class A hospital in China were recruited and randomized (1:1) to traditional nasal catheter oxygen therapy or HFNC. Primary outcomes were dyspnea, oral dryness, and sleep condition, which were recorded after 72-h treatment. Secondary outcomes were heart rate (HR), respiration rate (RR), S_pO₂, P_aO₂, and P_aCO₂, which were recorded after 2, 6, 24, and 72 h treatment.

RESULTS

Seventy-two hours after treatment, there were significant improvements in all primary outcomes (P < 0.001). P_aO₂ and RR were statistically changed 2 h after HFNC treatment (P < 0.001). P_aCO₂ and HR were statistically changed 24 h after HFNC treatment (P < 0.001).

CONCLUSION

HFNC oxygen therapy has good effect, high safety, and is easy to be accepted by dyspnea patients with advanced cancer. It can be used as the first choice of oxygen therapy for these patients and has broad clinical prospects.

TRIAL REGISTRATION

This work was retrospectively registered in the Chinese Clinical Trials Registry (ChiCTR2100049582) on August 4, 2021.

High Flow Nasal Cannula compared to Continuous Positive Airway Pressure: a bench and physiological study

High-flow nasal cannula (HFNC) is extensively used for acute respiratory failure. However, questions remain regarding its physiological effects. We explored 1) whether HFNC produced similar effects to continuous positive airway pressure (CPAP); 2) possible explanations of respiratory rate changes; 3) the effects of mouth opening. Two studies were conducted: a bench study using a manikin's head with lungs connected to a breathing simulator while delivering HFNC flow rates from 0 to 60L/min; a physiological cross-over study in 10 healthy volunteers receiving HFNC (20 to 60L/min) with the mouth open or closed and CPAP 4cmH2O delivered through face-mask. Nasopharyngeal and esophageal pressures were measured; tidal volume and flow were estimated using calibrated electrical impedance tomography. In the bench study, nasopharyngeal pressure at end-expiration reached 4cmH2O with HFNC at 60L/min, while tidal volume decreased with increasing flow. In volunteers with HFNC at 60L/min, nasopharyngeal pressure reached 6.8cmH2O with mouth closed and 0.8cmH2O with mouth open; p<0.001. When increasing HFNC flow, respiratory rate decreased by lengthening expiratory time, tidal volume did not change, and effort decreased (pressure-time product of the respiratory muscles); at 40L/min, effort was equivalent between CPAP and HFNC40L/min and became lower at 60L/min (p=0.045). During HFNC with mouth closed, and not during CPAP, resistance to breathing was increased, mostly during expiration. In conclusion, mouth closure during HFNC induces a positive nasopharyngeal pressure proportional to flow rate and an increase in expiratory resistance that might explain the prolonged expiration and reduction in respiratory rate and effort, and contribute to physiological benefits.

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.

Perioperative Pulmonary Atelectasis: Part II. Clinical Implications

The development of pulmonary atelectasis is common in the surgical patient. Pulmonary atelectasis can cause various degrees of gas exchange and respiratory mechanics impairment during and after surgery. In its most serious presentations, lung collapse could contribute to postoperative respiratory insufficiency, pneumonia, and worse overall clinical outcomes. A specific risk assessment is critical to allow clinicians to optimally choose the anesthetic technique, prepare appropriate monitoring, adapt the perioperative plan, and ensure the patient's safety. Bedside diagnosis and management have benefited from recent imaging advancements such as lung ultrasound and electrical impedance tomography, and monitoring such as esophageal manometry. Therapeutic management includes a broad range of interventions aimed at promoting lung recruitment. During general anesthesia, these strategies have consistently demonstrated their effectiveness in improving intraoperative oxygenation and respiratory compliance. Yet these same intraoperative strategies may fail to affect additional postoperative pulmonary outcomes. Specific attention to the postoperative period may be key for such outcome impact of lung expansion. Interventions such as noninvasive positive pressure ventilatory support may be beneficial in specific patients at high risk for pulmonary atelectasis (e.g., obese) or those with clinical presentations consistent with lung collapse (e.g., postoperative hypoxemia after abdominal and cardiothoracic surgeries). Preoperative interventions may open new opportunities to minimize perioperative lung collapse and prevent pulmonary complications. Knowledge of pathophysiologic mechanisms of atelectasis and their consequences in the healthy and diseased lung should provide the basis for current practice and help to stratify and match the intensity of selected interventions to clinical 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.

Some characteristics of clinical sequelae of COVID-19 survivors from Wuhan, China: A multi-center longitudinal study

Background

The pandemic of COVID‐19 has a persistent impact on global health, yet its sequelae need to be addressed at a wide scale around the globe. This study aims to investigate the characteristics, prevalence, and risk factors for mid‐term (>6 months) clinical sequelae in a cohort of COVID‐19 survivors.

Methods

Totally 715 COVID‐19 survivors discharged before April 1, 2020, from three medical centers in Wuhan, China, were included. The longitudinal study was conducted by telephone interviews based on a questionnaire including the clinical sequelae of general, respiratory, and cardiovascular systems. Demographics and some characteristics of clinical sequelae of the survivors were recorded and analyzed. Multivariate logistic regression analysis was applied to explore the risk factors for the sequelae.

Results

The median time interval from discharge to telephone interview was 225.0 days. The COVID‐19 survivors' median ages were 69 years, and 51.3% were male. Among them, 29.9% had at least one clinical sequela. There were 19.2%, 22.7%, and 5.0% of the survivors reporting fatigue, respiratory symptoms, and cardiovascular symptoms, respectively. Comorbidities, disease severity, the application of mechanical ventilation and high‐flow oxygen therapy, and the history of re‐admission were associated with the presence of clinical sequelae.

Conclusions

Our study provides further evidence for the prevalence and characteristics of clinical sequelae of COVID‐19 survivors, suggesting long‐term monitoring and management is needed for their full recovery.

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.

Oxygenation strategies after extubation of critically ill and postoperative patients

In intensive care units (ICUs), the decision to extubate is a critical one because mortality is particularly high in case of reintubation. Around 15% of patients ready to be weaned off a ventilator experience extubation failure leading to reintubation. The use of high-flow nasal oxygen and non-invasive ventilation are two alternatives of standard oxygen supplementation that may help to prevent reintubation. High-flow nasal oxygen and non-invasive ventilation, may be used to prevent reintubation in patients with low (e.g., patients without comorbidities and with short durations of mechanical ventilation) and high risk (e.g., patients >65 years and those with underlying cardiac disease, chronic respiratory disorders, and/or hypercapnia at the time of extubation) of reintubation, respectively. However, non-invasive ventilation used as a rescue therapy to treat established post-extubation respiratory failure could increase mortality by delaying reintubation, and should therefore be used very carefully in this setting. The oxygenation strategy to be applied in postoperative patients is different from the patients who are extubated in the ICUs. Standard oxygen after a surgical procedure is adequate, even following major abdominal or cardiothoracic surgery, but should probably be switched to high-flow nasal oxygen in patients with hypoxemic. Unlike in patients experiencing post-extubation respiratory failure in ICUs wherein non-invasive ventilation may have deleterious effects, it may actually improve the outcomes in postoperative patients with respiratory failure. This review discusses the different clinical situations with the aim of choosing the most effective oxygenation strategy to prevent post-extubation respiratory failure and to avoid reintubation.

Summary of recommendations and key points of the consensus of Spanish scientific societies (SEPAR, SEMICYUC, SEMES; SECIP, SENEO, SEDAR, SENP) on the use of non-invasive ventilation and high-flow oxygen therapy with nasal cannulas in adult, pediatric, and neonatal patients with severe acute respiratory failure

Non-invasive respiratory support (NIRS) in adult, pediatric, and neonatal patients with acute respiratory failure (ARF) comprises two treatment modalities, non-invasive mechanical ventilation (NIMV) and high-flow nasal cannula (HFNC) therapy. However, experts from different specialties disagree on the benefit of these techniques in different clinical settings. The objective of this consensus was to develop a series of good clinical practice recommendations for the application of non-invasive support in patients with ARF, endorsed by all scientific societies involved in the management of adult and pediatric/neonatal patients with ARF. To this end, the different societies involved were contacted, and they in turn appointed a group of 26 professionals with sufficient experience in the use of these techniques. Three face-to-face meetings were held to agree on recommendations (up to a total of 71) based on a literature review and the latest evidence associated with 3 categories: indications, monitoring and follow-up of NIRS. Finally, the experts from each scientific society involved voted telematically on each of the recommendations. To classify the degree of agreement, an analogue classification system was chosen that was easy and intuitive to use and that clearly stated whether the each NIRS intervention should be applied, could be applied, or should not be applied.

Summary of Recommendations and Key Points of the Consensus of Spanish Scientific Societies (SEPAR, SEMICYUC, SEMES; SECIP, SENEO, SEDAR, SENP) on the Use of Non-Invasive Ventilation and High-Flow Oxygen Therapy with Nasal Cannulas in Adult, Pediatric, and Neonatal Patients With Severe Acute Respiratory Failure

Non-invasive respiratory support (NIRS) in adult, pediatric, and neonatal patients with acute respiratory failure (ARF) comprises two treatment modalities, non-invasive mechanical ventilation (NIMV) and high-flow nasal cannula (HFNC) therapy. However, experts from different specialties disagree on the benefit of these techniques in different clinical settings. The objective of this consensus was to develop a series of good clinical practice recommendations for the application of non-invasive support in patients with ARF, endorsed by all scientific societies involved in the management of adult and pediatric/neonatal patients with ARF. To this end, the different societies involved were contacted, and they in turn appointed a group of 26 professionals with sufficient experience in the use of these techniques. Three face-to-face meetings were held to agree on recommendations (up to a total of 71) based on a literature review and the latest evidence associated with 3 categories: indications, monitoring and follow-up of NIRS. Finally, the experts from each scientific society involved voted telematically on each of the recommendations. To classify the degree of agreement, an analog classification system was chosen that was easy and intuitive to use and that clearly stated whether the each NIRS intervention should be applied, could be applied, or should not be applied.

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.

Effect of High-Flow Nasal Cannula for Hypoxemia Following Sun's Procedure in Acute Aortic Dissection Type a Patients

Background: Patients with acute aortic dissection type A (AADA) often have hypoxemia (partial pressure of oxygen [PaO₂]/fraction of inspired oxygen [FiO₂] <300 mmHg) before weaning in the intensive care unit (ICU). This study compared the efficacy of high-flow nasal cannula (HFNC) with that of conventional oxygen therapy (COT) in patients with AADA following Sun's procedure.

Methods: The medical records of 87 adult patients with AADA who underwent Sun's procedure and met the inclusion criteria (PaO₂/FiO₂ <300 mmHg before weaning) were retrospectively analyzed. After surgery, 41 patients were treated with HFNC and 46 were treated with COT. The oxygenation level, FiO₂, partial pressure of carbon dioxide, heart rate, respiratory rate, subjective discomfort, and reintubation rate were recorded. The difference in lung volume loss between the HFNC and COT groups was assessed using the radiological atelectasis score (chest radiograph) or calculated from three-dimensional (3D) reconstructed computed tomography (CT) images.

Results: From day 1 to day 5 after weaning, there was no significant difference in PaO₂/FiO₂ between the HFNC and COT groups, although the FiO₂ was significantly lower in the HFNC group than in the COT group (P < 0.05). Further studies indicated that the percentage of lung volume loss (pleural effusion and/or pulmonary atelectasis) by 3D reconstruction of CT images at 4–8 days post-operation was significantly lower in the HFNC group (P < 0.05). The subjective experience of breathing discomfort, reintubation rate, and length of stay in the ICU were significantly reduced in the HFNC group (P < 0.05). There was no significant difference in readmission to the ICU and in-hospital mortality between the two groups.

Conclusions: HFNC can be used as an effective oxygen therapy for AADA patients with hypoxemia after Sun's procedure.

Post-extubation oxygenation strategies in acute respiratory failure: a systematic review and network meta-analysis

Background

High-flow nasal cannula oxygenation (HFNC) and noninvasive positive-pressure ventilation (NPPV) possibly decrease tracheal reintubation rates better than conventional oxygen therapy (COT); however, few large-scale studies have compared HFNC and NPPV. We conducted a network meta-analysis (NMA) to compare the effectiveness of three post-extubation respiratory support devices (HFNC, NPPV, and COT) in reducing the mortality and reintubation risk.

Methods

The Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, and Ichushi databases were searched. COT, NPPV, and HFNC use were assessed in patients who were aged ≥ 16 years, underwent invasive mechanical ventilation for > 12 h for acute respiratory failure, and were scheduled for extubation after spontaneous breathing trials. The GRADE Working Group Approach was performed using a frequentist-based approach with multivariate random-effect meta-analysis. Short-term mortality and reintubation and post-extubation respiratory failure rates were compared.

Results

After evaluating 4631 records, 15 studies and 2600 patients were included. The main cause of acute hypoxic respiratory failure was pneumonia. Although NPPV/HFNC use did not significantly lower the mortality risk (relative risk [95% confidence interval] 0.75 [0.53–1.06] and 0.92 [0.67–1.27]; low and moderate certainty, respectively), HFNC use significantly lowered the reintubation risk (0.54 [0.32–0.89]; high certainty) compared to COT use. The associations of mortality with NPPV and HFNC use with respect to either outcome did not differ significantly (short-term mortality and reintubation, relative risk [95% confidence interval] 0.81 [0.61–1.08] and 1.02 [0.53–1.97]; moderate and very low certainty, respectively).

Conclusion

NPPV or HFNC use may not reduce the risk of short-term mortality; however, they may reduce the risk of endotracheal reintubation.

Trial registration number and date of registration

PROSPERO (registration number: CRD42020139112, 01/21/2020).

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-021-03550-4.

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.

Summary of Recommendations and Key Points of the Consensus of Spanish Scientific Societies (SEPAR, SEMICYUC, SEMES; SECIP, SENEO, SEDAR, SENP) on the Use of Non-Invasive Ventilation and High-Flow Oxygen Therapy with Nasal Cannulas in Adult, Pediatric, and Neonatal Patients with Severe Acute Respiratory Failure

Non-invasive respiratory support (NIRS) in adult, pediatric, and neonatal patients with acute respiratory failure (ARF) comprises two treatment modalities, non-invasive mechanical ventilation (NIMV) and high-flow nasal cannula (HFNC) therapy. However, experts from different specialties disagree on the benefit of these techniques in different clinical settings. The objective of this consensus was to develop a series of good clinical practice recommendations for the application of non-invasive support in patients with ARF, endorsed by all scientific societies involved in the management of adult and pediatric/neonatal patients with ARF. To this end, the different societies involved were contacted, and they in turn appointed a group of 26 professionals with sufficient experience in the use of these techniques. Three face-to-face meetings were held to agree on recommendations (up to a total of 71) based on a literature review and the latest evidence associated with 3 categories: indications, monitoring and follow-up of NIRS. Finally, the experts from each scientific society involved voted telematically on each of the recommendations. To classify the degree of agreement, an analogue classification system was chosen that was easy and intuitive to use and that clearly stated whether the each NIRS intervention should be applied, could be applied, or should not be applied.

Summary of recommendations and key points of the consensus of Spanish scientific societies (SEPAR, SEMICYUC, SEMES; SECIP, SENEO, SEDAR, SENP) on the use of non-invasive ventilation and high-flow oxygen therapy with nasal cannulas in adult, pediatric, and neonatal patients with severe acute respiratory failure

Non-invasive respiratory support (NIRS) in adult, pediatric, and neonatal patients with acute respiratory failure (ARF) comprises two treatment modalities, non-invasive mechanical ventilation (NIMV) and high-flow nasal cannula (HFNC) therapy. However, experts from different specialties disagree on the benefit of these techniques in different clinical settings. The objective of this consensus was to develop a series of good clinical practice recommendations for the application of non-invasive support in patients with ARF, endorsed by all scientific societies involved in the management of adult and pediatric/neonatal patients with ARF. To this end, the different societies involved were contacted, and they in turn appointed a group of 26 professionals with sufficient experience in the use of these techniques. Three face-to-face meetings were held to agree on recommendations (up to a total of 71) based on a literature review and the latest evidence associated with 3 categories: indications, monitoring and follow-up of NIRS. Finally, the experts from each scientific society involved voted telematically on each of the recommendations. To classify the degree of agreement, an analogue classification system was chosen that was easy and intuitive to use and that clearly stated whether the each NIRS intervention should be applied, could be applied, or should not be applied.

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.

Application of a High-Flow Nasal Cannula for Prevention of Postextubation Atelectasis in Children Undergoing Surgery: A Randomized Controlled Trial

BACKGROUND

General anesthesia-induced atelectasis is common, and persistent postoperative atelectasis is associated with pulmonary complications. We aimed to evaluate the preventive effects of a high-flow nasal cannula (HFNC) on postoperative atelectasis and respiratory complications in infants and small children.

METHODS

In this prospective randomized controlled trial, children (≤2 years) receiving general anesthesia (>2 hours) were randomized into the control and HFNC groups. At the end of the surgery, the first lung ultrasound evaluation was performed in both groups. In the postanesthetic care unit (PACU), the control group received conventional oxygen therapy, while the HFNC group received oxygen via HFNC, with a flow rate of 2 L kg-1 min-1. Before discharge to the ward, a second lung ultrasound examination was performed. The primary outcome was the lung ultrasound score at PACU discharge. The secondary outcomes included the lung ultrasound score at the end of surgery, the incidence of significant atelectasis at PACU discharge, and other postoperative outcomes.

RESULTS

Lung ultrasound score and the incidence of atelectasis at the end of surgery did not differ significantly between the control (n = 38) and HFNC (n = 40) groups. After staying in the PACU, both groups showed a reduced lung ultrasound score and atelectasis incidence. However, the HFNC group had a significantly lower consolidation score than the control group (0; interquartile range [IQR] = 0-1 vs 3; IQR = 2-4; P< .001). Additionally, none of the patients had significant atelectasis in the HFNC group, compared to 6 patients in the control group (0% vs 15.8%; odds ratio [OR] = 0.444; 95% confidence interval for OR, 0.343-0.575; P = .011). Incidence of desaturation (oxygen saturation [Spo2] ≤ 95%), postoperative complications, and the length of hospital stay did not differ between the groups.

CONCLUSIONS

Preventive use of HFNC after surgery improves the lung ultrasound score and reduces postoperative atelectasis compared to conventional oxygen therapy in infants and small children.

Effect of oxygenation modalities among patients with postoperative respiratory failure: a pairwise and network meta-analysis of randomized controlled trials

Background

Postoperative respiratory failure is associated with increased perioperative complications. Our aim is to compare outcomes between non-invasive ventilation (NIV), high-flow nasal cannula (HFNC), and standard oxygen in patients at high-risk for or with established postoperative respiratory failure.

Methods

Electronic databases including PubMed, Embase, and the Cochrane Library were reviewed from inception to September 2019. We included only randomized controlled trials (RCTs) that compared NIV, HFNC, and standard oxygen in patients at high risk for or with established postoperative respiratory failure. We performed a Bayesian network meta-analysis to calculate the odds ratio (OR) and Bayesian 95% credible intervals (CrIs).

Results

Nine RCTs representing 1865 patients were included (the mean age was 61.6 ± 10.2 and 64.4% were males). In comparison with standard oxygen, NIV was associated with a significant reduction in intubation rate (OR 0.23; 95% Cr.I. 0.10–0.46), mortality (OR 0.45; 95% Cr.I. 0.27–0.71), and intensive care unit (ICU)-acquired infections (OR 0.43, 95% Cr.I. 0.25–0.70). Compared to standard oxygen, HFNC was associated with a significant reduction in intubation rate (OR 0.28, 95% Cr.I. 0.08–0.76) and ICU-acquired infections (OR 0.41; 95% Cr.I. 0.20–0.80), but not mortality (OR 0.58; 95% Cr.I. 0.26–1.22). There were no significant differences between HFNC and NIV regarding different outcomes. In a subgroup analysis, we observed a mortality benefit with NIV over standard oxygen in patients undergoing cardiothoracic surgeries but not in abdominal surgeries. Furthermore, in comparison with standard oxygen, NIV and HFNC were associated with lower intubation rates following cardiothoracic surgeries while only NIV reduced the intubation rates following abdominal surgeries.

Conclusions

Among patients with post-operative respiratory failure, HFNC and NIV were associated with significantly reduced rates of intubation and ICU-acquired infections compared with standard oxygen. Moreover, NIV was associated with reduced mortality in comparison with standard oxygen.

Noninvasive respiratory support in the hypoxaemic peri-operative/periprocedural patient: a joint ESA/ESICM guideline

Hypoxaemia is a potential life-threatening yet common complication in the peri-operative and periprocedural patient (e.g. during an invasive procedure at risk of deterioration of gas exchange, such as bronchoscopy). The European Society of Anaesthesiology (ESA) and the European Society of Intensive Care Medicine (ESICM) developed guidelines for the use of noninvasive respiratory support techniques in the hypoxaemic patient in the peri-operative and periprocedural period. The panel outlined five clinical questions regarding treatment with noninvasive respiratory support techniques [conventional oxygen therapy (COT), high flow nasal cannula, noninvasive positive pressure ventilation (NIPPV) and continuous positive airway pressure (CPAP)] for hypoxaemic patients with acute peri-operative/periprocedural respiratory failure. The goal was to assess the available literature on the various noninvasive respiratory support techniques, specifically studies that included adult participants with hypoxaemia in the peri-operative/periprocedural period. The literature search strategy was developed by a Cochrane Anaesthesia and Intensive Care trial search specialist in close collaboration with the panel members and the ESA group methodologist. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) system was used to assess the level of evidence and to grade recommendations. The final process was then validated by both ESA and ESICM scientific committees. Among 19 recommendations, the two grade 1B recommendations state that: in the peri-operative/periprocedural hypoxaemic patient, the use of either NIPPV or CPAP (based on local expertise) is preferred to COT for improvement of oxygenation; and that the panel suggests using NIPPV or CPAP immediately post-extubation for hypoxaemic patients at risk of developing acute respiratory failure after abdominal surgery.

High-flow nasal cannula versus conventional oxygen therapy in patients with dyspnea and hypoxemia before hospitalization

Introduction: Patients with dyspnea and hypoxemia are common in emergency departments. However, it is unknown whether high-flow nasal cannula (HFNC) reduces the risk of requiring more advanced ventilation support and whether HFNC relieves dyspnea better than conventional oxygen therapy (COT).Areas covered: We searched the PubMed, Cochrane Library, Ovid, and Embase databases from inception to 1 September 2019 to identify relevant-randomized controlled trials comparing the effect of HFNC with COT in emergency departments regarding the severity of dyspnea, hospitalization rate, intubation rate, and hospital mortality. We identified four studies. HFNC was associated with a lower rate of requiring more advanced ventilation. HFNC reduced the rate of dyspnea, lowered the dyspnea scale score, and decreased patients' respiratory rate significantly. However, there was insufficient evidence to show a significant effect on HFNC regarding patients' oxygenation and hospital mortality.Expert opinion: For patients with dyspnea and hypoxemia before hospitalization, the short-term effect of HFNC was undeniable. HFNC reduced the risk of requiring more advanced ventilation and relived dyspnea better than COT. HFNC might be considered as a first-line therapy even before making a clear diagnosis for dyspnea.More studies are needed to explore the effect of HFNC on oxygenation and patients' prognosis.

Simultaneous reduction of flow and fraction of inspired oxygen (FiO2) versus reduction of flow first or FiO2 first in patients ready to be weaned from high-flow nasal cannula oxygen therapy: study protocol for a randomized controlled trial (SLOWH trial)

BACKGROUND

High-flow nasal cannula (HFNC) oxygen therapy has been widely used in critically ill patients. Despite the effectiveness of HFNC as a treatment, optimal methods to withdraw HFNC after recovery from preexisting conditions have not been investigated to date. In this study, we will evaluate the safety and efficacy of simultaneous reduction of flow and fraction of inspired oxygen (FiO₂) compared with sequential reduction of either flow first or FiO₂ reduction first in patients with HFNC.

METHODS/DESIGN

This is a prospective, investigator-initiated, randomized controlled trial with three experimental intervention groups. A total of 100 adult patients receiving HFNC and satisfying weaning criteria will be enrolled and randomly assigned to one of the following groups: flow reduction (FR) first, FiO₂ reduction (OR) first, or simultaneous reduction (SR). In the FR group, flow will be reduced first by 10 L/min/h. When it reaches 20 L/min, FiO₂ will then be reduced by 0.1 /h until it reaches 0.3. In the OR group, the FiO₂ will be gradually reduced first by 0.1 /h until it reaches 0.3, then flow will be reduced by 10 L/min until it reaches 20 L/min. Finally, in the SR group, both the flow and FiO₂ will be gradually reduced simultaneously by 10 L/min and 0.1/h, respectively. Weaning will proceed only when patients satisfy the weaning criteria at every weaning point. When the HFNC weaning-off targets are reached (20 L/min and 0.3 for flow and FiO_2, respectively), the patient will be transferred to conventional oxygen therapy (mainly low-flow nasal prongs). The primary outcome is the time to successful weaning from HFNC for 24 h. Secondary outcomes will include the success or failure rate in weaning off HFNC and changes in arterial blood gas analyses, intolerance rate, length of hospital stay, and in-hospital mortality.

DISCUSSION

This study will be the first clinical trial to investigate the safety and efficacy of three different methods of weaning in adult patients receiving HFNC. Once this study is completed, we expect to be able to suggest the better strategy for withdrawal of HFNC based on the results.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT03845244. Registered on 19 February 2019.

Nasal High Flow Versus Conventional Oxygen Therapy for Postoperative Cardiothoracic Surgery Patients

BACKGROUND

Reintubation and complications in postoperative cardiothoracic patients remain high despite medical advancements. A 2-year retrospective, observational study was conducted in postextubated cardiothoracic patients to assess the effectiveness of the current standard-conventional oxygen therapy (COT) compared with a nasal high flow (NHF) therapy.

OBJECTIVES

The objective of this study was to understand whether NHF therapy would reduce the need for reintubation and improve clinical outcomes after surgery.

METHOD

All consecutive postoperative patients who had same-day elective cardiothoracic surgery in a tertiary hospital were included. The 2013 data were from patients' charts who received COT, and the 2014 data were from patients' charts after the implementation of NHF therapy post extubation as a standard of care.

RESULTS

A total of 400 patient charts were analyzed: 221 and 179 patients in the COT and NHF, respectively. No significant difference was seen in the frequency of reintubation (P = .48). Despite both cohorts having the same length of stay (P = .10), patients treated with NHF required less time on supplemental oxygen (P = .001). Day 1 postoperative chest x-ray results did not show any significant differences between groups, whereas day 2 x-rays showed worsening results in the COT cohort (P < .001). Furthermore, the incidence of ventilator-associated pneumonia (VAP) post extubation was significantly higher in the COT cohort, with zero VAP episodes reported in the NHF cohort (P = .02).

DISCUSSION

Although this study was not able to demonstrate the reduction in reintubation between groups, the use of NHF compared with COT seems to reduce the time spent on oxygen therapy and decrease the rate of VAP. Further evidence including randomized controlled trials is required to determine the impact of NHF on reintubation and complications in postoperative cardiothoracic surgery.

High-flow nasal cannula therapy: clinical practice in intensive care units

Background

Despite the extensive use of high-flow nasal cannula (HFNC) therapy in intensive care units (ICU) for acute respiratory failure (ARF), its daily clinical practice has not been assessed. We designed a regional survey in ICUs in North-west France to evaluate ICU physicians’ clinical practice with HFNC.

Materials and methods

We sent an observational survey to ICU physicians from 34 French ICUs over a 6-month period in 2016–2017. The survey included questions regarding the indications and expected efficiency of HFNC, practical aspects of use (initiation, weaning) and satisfaction. Comparisons between junior and senior ICU physicians were performed using a Fischer exact test.

Results

Among the 235 ICU physicians contacted, 137 responded (58.3%) all of whom regularly used HFNC. Hypoxemic ARF was considered a good indication for HFNC by all 137, but only 30% expected HFNC success (i.e., avoiding intubation in at least 60% of cases). Among hypoxemic indications, 30% of juniors considered acute pulmonary edema a good indication versus 74% of seniors (p < 0.0001). Hypercapnic ARF was considered a good indication by 33% with only 2% expecting HFNC success. A need for conventional oxygen therapy ≥ 6 L/min justified HFNC therapy for 40% and ≥ 9 L/min for 39% of responders. 58% of ICU physicians started HFNC therapy with a FiO₂ ≥ 50% and 28% with a gas flow ≥ 50 L/min. Practices for HFNC weaning were heterogeneous: 48% considered a FiO₂ ≤ 30%; whereas, 30% considered a FiO₂ ≤ 30% with a high flow ≤ 20 L/min. Criteria for HFNC failure (i.e., need for intubation) were ventilatory pauses or arrest (97%), persistent hypoxemia (95%), respiratory acidosis (81%), worsening of breathing (95%, 100% of seniors and 86% of juniors, p = 0.003), bronchial congestion (75%) and circulatory failure (61%, 72% of seniors and 44% of juniors, p = 0.007).

Conclusion

HFNC is used by ICU physicians in many situations of ARF, despite their relatively low expectations of success, especially in cases of hypercapnia. Clinical practices appear somewhat heterogeneous. Despite the physiological benefit of HFNC, further prospective observational studies are still required on HFNC outcomes and daily practices.

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.

Ventilatory support after extubation in critically ill patients

The periextubation period represents a crucial moment in the management of critically ill patients. Extubation failure, defined as the need for reintubation within 2-7 days after a planned extubation, is associated with prolonged mechanical ventilation, increased incidence of ventilator-associated pneumonia, longer intensive care unit and hospital stays, and increased mortality. Conventional oxygen therapy is commonly used after extubation. Additional methods of non-invasive respiratory support, such as non-invasive ventilation and high-flow nasal therapy, can be used to avoid reintubation. The aim of this Review is to describe the pathophysiological mechanisms of postextubation respiratory failure and the available techniques and strategies of respiratory support to avoid reintubation. We summarise and discuss the available evidence supporting the use of these strategies to achieve a tailored therapy for an individual patient at the bedside.

Study protocol: A randomized controlled trial assessing the avoidance of endotracheal suction in cardiac surgical patients ventilated for ≤ 12 hr

AIMS

To assess the safety and efficacy of avoiding endotracheal suction in postoperative cardiac surgical patients mechanically ventilated for ≤ 12 hr.

DESIGN

A prospective, single centre, single blind, non-inferiority, randomized controlled trial evaluating the safety and efficacy of avoiding suction in uncomplicated, postoperative, adult cardiac surgical patients mechanically ventilated for ≤ 12 hr.

METHODS

Randomization will be performed on return to intensive care (ICU) with allocation to either usual postoperative care including suction or to usual care with no suction (intervention arm). The primary outcome is the ratio of partial pressure of oxygen (PaO₂ ) to fraction of inspired oxygen (FiO₂ ) (P/F) 6 hr after extubation. Pain assessments will be performed before, during and after endotracheal suction (ETS) and the patient experience will be investigated with a brief interview the following day. Ethics approval was received in October 2015.

DISCUSSION

Endotracheal suction is performed as part of airway management but has potential complications and there is little robust evidence to guide practice. This study will add to the evidence base about the need and benefit of endotracheal suction in this patient cohort.

IMPACT

As there is currently no published evidence about the safety of avoiding endotracheal suction. This study will provide the first evidence about avoidance of endotracheal suction in patients ventilated for less than 1 day. If non-inferior, the results have the capacity to change nursing practice by avoiding a potentially unnecessary procedure, it will build on the body of knowledge about the patient experience.

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.

High-Flow Therapy by Nasal Cannulae Versus High-Flow Face Mask in Severe Hypoxemia After Cardiac Surgery: A Single-Center Randomized Controlled Study-The HEART FLOW Study

OBJECTIVE

To determine whether high-flow oxygen therapy by nasal cannulae (HFNC) is more effective than a high-flow face mask (HFFM) in severe hypoxemia.

DESIGN

Randomized, single-center, open-labeled, controlled trial.

SETTING

University Hospital of Nantes, France.

PARTICIPANTS

Cardiac surgery patients presenting oxygen saturation <96% with Venturi mask 50%.

INTERVENTION

Oxygenation by HFNC (45 L/min, F_IO₂ 100%) or Hudson RCI non-rebreather face mask with a reservoir bag (15 L/min).

MEASUREMENTS AND MAIN RESULTS

The co-primary outcomes were the PaO₂/F_IO₂ ratio at 1 and 24 hours. In the intent-to-treat analysis (90 patients), the mean (standard deviation) PaO₂/F_IO₂ ratios were: after 1 hour, 113.4 (50.2) in HFFM versus 137.8 (57.0) in HFNC (mean difference 24.4, CI 97.5% [2.9-45.9], p = 0.03), and after 24 hours, 106.9 (62.6) in HFFM versus 129.9 (54.0) in HFNC (mean difference 23.0, CI 97.5% [1.5-44.6], p = 0.04). After adjustment on baseline PaO₂/F_IO_2, this difference persisted at 24 hours (p = 0.04). For secondary outcomes, the PaO₂/F_IO₂ ratio after 6 hours was 108.7 (47.9) in HFFM versus 136.0 (45.2) in HFNC (p = 0.01), without difference after 48 hours (p = 0.95). Refractory hypoxemia requiring noninvasive ventilation occurred in 13 (28%) patients in HFNC versus 24 (56%) patients in HFFM (p = 0.007). The HFNC improved satisfaction (p = 0.0002) and reduced mucus dryness (p = 0.003) compared with HFFM.

CONCLUSION

In patients with severe hypoxemia after cardiac surgery, PaO₂/F_IO₂ at 1 and 24 hours were higher and the use of noninvasive ventilation was reduced in HFNC compared with HFFM.

High-flow nasal cannula oxygen therapy versus conventional oxygen therapy in patients after planned extubation: a systematic review and meta-analysis

BACKGROUND

The effect of high-flow nasal cannula (HFNC) therapy in patients after planned extubation remains inconclusive. We aimed to perform a rigorous and comprehensive systematic meta-analysis to robustly quantify the benefits of HFNC for patients after planned extubation by investigating postextubation respiratory failure and other outcomes.

METHOD

We searched MEDLINE, EMBASE, Web of Science, and the Cochrane Library from inception to August 2018. Two researchers screened studies and collected the data independently. Randomized controlled trials (RCTs) and crossover studies were included. The main outcome was postextubation respiratory failure.

RESULTS

Ten studies (seven RCTs and three crossover studies; HFNC group: 856 patients; Conventional oxygen therapy (COT) group: 852 patients) were included. Compared with COT, HFNC may significantly reduce postextubation respiratory failure (RR, 0.61; 95% CI, 0.41, 0.92; z = 2.38; P = 0.02) and respiratory rates (standardized mean differences (SMD), - 0.70; 95% CI, - 1.16, - 0.25; z = 3.03; P = 0.002) and increase PaO₂ (SMD, 0.30; 95% CI, 0.04, 0.56; z = 2.23; P = 0.03). There were no significant differences in reintubation rate, length of ICU and hospital stay, comfort score, PaCO₂, mortality in ICU and hospital, and severe adverse events between HFNC and COT group.

CONCLUSIONS

Our meta-analysis demonstrated that compared with COT, HFNC may significantly reduce postextubation respiratory failure and respiratory rates, increase PaO₂, and be safely administered in patients after planned extubation. Further large-scale, multicenter studies are needed to confirm our results.

Early high-flow nasal cannula oxygen therapy in adults with acute hypoxemic respiratory failure in the ED: A before-after study

OBJECTIVES

To compare clinical impact after early initiation of high-flow nasal cannula oxygen therapy (HFNC) versus standard oxygen in patients admitted to an emergency department (ED) for acute hypoxemic respiratory failure.

METHODS

We performed a prospective before-after study at EDs in two centers including patients with acute hypoxemic respiratory failure defined by a respiratory rate above 25 breaths/min or signs of increased breathing effort under additional oxygen for a pulse oximetry above 92%. Patients with cardiogenic pulmonary edema or exacerbation of chronic lung disease were excluded. All patients were treated with standard oxygen during the first period and with HFNC during the second. The primary outcome was the proportion of patients with improved respiratory failure 1 h after treatment initiation (respiratory rate ≤ 25 breaths/min without signs of increased breathing effort). Dyspnea and blood gases were also assessed.

RESULTS

Among the 102 patients included, 48 were treated with standard oxygen and 54 with HFNC. One hour after treatment initiation, patients with HFNC were much more likely to recover from respiratory failure than those treated with standard oxygen: 61% (33 of 54 patients) versus 15% (7 of 48 patients), P < 0.001. They also showed greater improvement in oxygenation (increase in PaO₂ was 31 mm Hg [0-67] vs. 9 [-9-36], P = 0.02), and in feeling of breathlessness.

CONCLUSIONS

As compared to standard oxygen, patients with acute hypoxemic respiratory failure treated with HFNC at the ED had better oxygenation, less breathlessness and were more likely to show improved respiratory failure 1 h after initiation.