High-flow Nasal Therapy Research Articles

High-flow nasal cannula oxygen therapy decreases postextubation neuroventilatory drive and work of breathing in patients with chronic obstructive pulmonary disease

BackgroundThe physiological effects of high-flow nasal cannula O2 therapy (HFNC) have been evaluated mainly in patients with hypoxemic respiratory failure. In this study, we compared the effects of HFNC and conventional low-flow O2 therapy on the neuroventilatory drive and work of breathing postextubation in patients with a background of chronic obstructive pulmonary disease (COPD) who had received mechanical ventilation for hypercapnic respiratory failure.MethodsThis was a single center, unblinded, cross-over study on 14 postextubation COPD patients who were recovering from an episode of acute hypercapnic respiratory failure of various etiologies. After extubation, each patient received two 1-h periods of HFNC (HFNC1 and HFNC2) alternated with 1 h of conventional low-flow O2 therapy via a face mask. The inspiratory fraction of oxygen was titrated to achieve an arterial O2 saturation target of 88–92%. Gas exchange, breathing pattern, neuroventilatory drive (electrical diaphragmatic activity (EAdi)) and work of breathing (inspiratory trans-diaphragmatic pressure-time product per minute (PTPDI/min)) were recorded.ResultsEAdi peak increased from a mean (±SD) of 15.4 ± 6.4 to 23.6 ± 10.5 μV switching from HFNC1 to conventional O2, and then returned to 15.2 ± 6.4 μV during HFNC2 (conventional O2: p < 0.05 versus HFNC1 and HFNC2). Similarly, the PTPDI/min increased from 135 ± 60 to 211 ± 70 cmH2O/s/min, and then decreased again during HFNC2 to 132 ± 56 (conventional O2: p < 0.05 versus HFNC1 and HFNC2).ConclusionsIn patients with COPD, the application of HFNC postextubation significantly decreased the neuroventilatory drive and work of breathing compared with conventional O2 therapy.

Extracorporeal membrane oxygenation support in a newborn with lower urinary tract obstruction and pulmonary hypoplasia: a case report

BackgroundSurvival of neonates with intrauterine renal insufficiency and oligo- or anhydramnios correlates with the severity of secondary pulmonary hypoplasia. Early prenatal diagnosis together with repetitive amnioinfusions and modern intensive care treatment have improved the prognosis of these neonates. Extracorporeal membrane oxygenation is an established treatment option, mainly applied to neonates with pulmonary hypoplasia caused by congenital diaphragmatic hernia. However, a few case reports of extracorporeal membrane oxygenation in neonates with lower urinary tract obstruction have been published.Case presentationWe describe a case of a Caucasian male infant with prenatally diagnosed lower urinary tract obstruction and secondary pulmonary hypoplasia who was delivered spontaneously at 36 + 2 weeks of gestation. Venovenous extracorporeal membrane oxygenation was initiated on the first day of life for severe respiratory failure and consecutive hypoxemia despite treatment with inhaled nitric oxide and high-frequency oscillation. The patient was supported by extracorporeal membrane oxygenation for 10 days and extubated 6 weeks later. Hemofiltration was required on the second day of life because of renal insufficiency and was later replaced by peritoneal dialysis. The child was discharged after 4 months with nasal high-flow mild oxygen therapy and peritoneal dialysis.ConclusionNeonatal extracorporeal membrane oxygenation support is a possible treatment option for neonates with lower urinary tract obstruction and pulmonary hypoplasia.

In Vitro Determination of the Main Effects in the Design of High-Flow Nasal Therapy Systems with Respect to Aerosol Performance.

IntroductionThe use of concurrent aerosol delivery during high-flow nasal therapy (HFNT) may be exploited to facilitate the delivery of a variety of prescribed medications for inhalation. Until now, a systematic approach to determine the conditions required to yield an optimal emitted dose has not been reported. The aim of this study was to establish the effects of gas flow rate, input droplet size, and nebulizer position on the amount of aerosol exiting the nasal cannula during HFNT and thus becoming available for inhalation.MethodsTesting was completed according to a factorial statistical design of experiments (DOE) approach. Emitted dose was characterized with a vibrating mesh nebulizer (Aerogen Solo, Aerogen Ltd) for an adult model of HFNT at three clinically relevant gas flow rates, using three nebulizers producing varying input droplet sizes and placed at two different nebulizer positions.ResultsIncreasing the gas flow rate significantly lowered the emitted dose, with a dose of 7.10% obtained at 10 LPM, 2.67% at 25 LPM, and 1.30% at 40 LPM (p < 0.0001). There was a significant difference in emitted dose between nebulizers with different input droplet sizes, with increasing input droplet size associated with a reduced emitted dose (6.11% with an input droplet size of 3.22 µm, 2.76% with 4.05 µm, and 2.38% with 4.88 µm, p = 0.0002, Pearson’s r = − 0.2871). In addition, the droplet size exiting the nasal cannula interface was lower than that produced by the aerosol generator for all devices under test. Positioning the nebulizer immediately after the humidification chamber yielded a marginally greater emitted dose (3.79%) than when the nebulizer was placed immediately upstream of the nasal cannula (3.39%). Flow rate, input droplet size, and nebulizer position were at the 0.10 level of significance, indicating that all three factors had significant effects on emitted dose. According to the DOE model, flow rate had the greatest influence on emitted dose, followed by input droplet size and then nebulizer position.ConclusionOur findings indicate that in order to optimize the amount of aerosol exiting the nasal cannula interface during HFNT, it is necessary for gas flow rate to be low and the input droplet size to be small, while the nebulizer should be positioned immediately after the humidification chamber.FundingAerogen Limited.

High flow nasal cannula oxygen therapy versus non-invasive ventilation for chronic obstructive pulmonary diseases with acute-moderate hypercapnic respiratory failure: an observational cohort study

Objective To compare the efficacy of high flow nasal cannula oxygen therapy (HFNC) and non-invasive ventilation (NIV) in the treatment of chronic obstructive pulmonary disease (COPD) with acute-moderate typeⅡ respiratory failure, and to explore the feasibility of HFNC in the treatment of COPD with respiratory failure. Methods Patients diagnosed with COPD with acute moderate typeⅡ respiratory failure (Arterial blood gas pH 7.25-7.35, PaCO2> 50 mmHg) admitted to the ICUs from April 2017 to December 2017 were retrospectively analyzed. All patients who were treated with HFNC within the first 4 hours after the admission to the ICUs, and continued for more than 2 hours and for at least 4 hours within the first 24 hours were included in the HFNC group. Those treated with NIV in the same conditions were included in the NIV group. The end point was the failure rates of treatment (changing to respiratory support method in another group or invasive ventilation) and 28-day mortality. Results Eighty-two patients (39 in the HFNC group and 43 in the NIV group) were enrolled. The HFNC group had a treatment failure rate of 28.2%, which was lower than that of the NIV group (39.5%). However, Kaplan-Meier curve analysis showed no significant difference between the two groups (Log Rank test 1.228, P=0.268). The 28-day mortality rate in HFNC group was 15.4%, which was no different from 14% in NIV group (Log Rank test 0.049, P=0.824). The number of airway care interventions within the first 24 hours was significantly lower in the HFNC group than in the NIV group [5 (3~8) vs. 11 (7~15)], whereas the duration of respiratory support within the first 24 hours was significantly longer in the HFNC group than in the NIV group [16 (9~22) hours vs. 8 (4~11) hours] (all P<0.05). The incidence of nasal facial lesions in the NIV group was 20.9%, significantly higher than that of HFNC group (5.1%, P <0.05). Conclusion For COPD with acute moderate typeⅡ respiratory failure, HFNC has similar therapeutic effects as NIV. HFNC has better therapeutic tolerance and is a new potential respiratory support method for clinical treatment of COPD with respiratory failure. Key words: Chronic obstructive pulmonary diseases; Respiratory failure; High-flow nasal cannula oxygen therapy; Non-invasive ventilation; Cohort study

Modelling nasal high flow therapy effects on upper airway resistance and resistive work of breathing

AimThe goal of this paper is to quantify upper airway resistance with and without nasal high flow (NHF) therapy. For adults, NHF therapy feeds 30–60 L/min of warm humidified air into the nose through short cannulas which do not seal the nostril. NHF therapy has been reported to increase airway pressure, increase tidal volume (Vt) and decrease respiratory rate (RR), but it is unclear how these findings affect the work done to overcome airway resistance to air flow during expiration. Also, there is little information on how the choice of nasal cannula size may affect work of breathing. In this paper, estimates of airway resistance without and with different NHF flow (applied via different cannula sizes) were made. The breathing efforts required to overcome airway resistance under these conditions were quantified. MethodNHF was applied via three different cannula sizes to a 3-D printed human upper airway. Pressure drop and flow rate were measured and used to estimate inspiratory and expiratory upper airway resistances. The resistance information was used to compute the muscular work required to overcome the resistance of the upper airway to flow. ResultsNHF raises expiratory resistance relative to spontaneous breathing if the breathing pattern does not change but reduces work of breathing if peak expiratory flow falls. Of the cannula sizes used, the large cannula produced the greatest resistance and the small cannula produced the least. The work required to cause tracheal flow through the upper airway was reduced if the RR and minute volume are reduced by NHF. NHF has been observed to do so in COPD patients (Bräunlich et al., 2013). A reduction in I:E ratio due to therapy was found to reduce work of breathing if the peak inspiratory flow is less than the flow below which no inspiratory effort is required to overcome upper airway resistance. ConclusionNHF raises expiratory resistance but it can reduce the work required to overcome upper airway resistance via a fall in inspiratory work of breathing, RR and minute volume.

Cost-Effectiveness Analysis of Nasal Continuous Positive Airway Pressure Versus Nasal High Flow Therapy as Primary Support for Infants Born Preterm

To compare the cost-effectiveness of 2 common "noninvasive" modes of respiratory support for infants born preterm. An economic evaluation was conducted as a component of a multicenter, randomized control trial from 2013 to 2015 enrolling infants born preterm at ≥28 weeks of gestation with respiratory distress, <24 hours old, who had not previously received endotracheal intubation and mechanical ventilation or surfactant. The economic evaluation was conducted from a healthcare sector perspective and the time horizon was from birth until death or first discharge. The cost-effectiveness of continuous positive airway pressure (CPAP) vs high-flow with "rescue" CPAP backup and high-flow without rescue CPAP backup (as sole primary support) were analyzed by using the hospital cost of inpatient stay in a tertiary center and the rates of endotracheal intubation and mechanical ventilation during admission. Hospital inpatient cost records for 435 infants enrolled in all Australian centers were obtained. With "rescue" CPAP backup, an incremental cost-effectiveness ratio was estimated of A$179 000 (US$123 000) per ventilation avoided if CPAP was used compared with high flow. Without rescue CPAP backup, cost per ventilation avoided was A$7000 (US$4800) if CPAP was used compared with high flow. As sole primary support, CPAP is highly likely to be cost-effective compared with high flow. Neonatal units choosing to use only one device should apply CPAP as primary respiratory support. Compared with high-flow with rescue CPAP backup, CPAP is unlikely to be cost-effective if willingness to pay per ventilation avoided is less than A$179 000 (US$123 000).

Refining the Use of Nasal High-Flow Therapy as Primary Respiratory Support for Preterm Infants

To identify clinical and demographic variables that predict nasal high-flow (nHF) treatment failure when used as a primary respiratory support for preterm infants. This secondary analysis used data from a multicenter, randomized, controlled trial comparing nHF with continuous positive airway pressure as primary respiratory support in preterm infants 28-36 completed weeks of gestation. Treatment success or failure with nHF was determined using treatment failure criteria within the first 72 hours after randomization. Infants in whom nHF treatment failed received continuous positive airway pressure, and were then intubated if failure criteria were again met. There were 278 preterm infants included, with a mean gestational age (GA) of 32.0 ± 2.1 weeks and a birth weight of 1737 ± 580 g; of these, nHF treatment failed in 71 infants (25.5%). Treatment failure was moderately predicted by a lower GA and higher prerandomization fraction of inspired oxygen (FiO2): area under a receiver operating characteristic curve of 0.76 (95% CI, 0.70-0.83). Nasal HF treatment success was more likely in infants born at ≥30 weeks GA and with prerandomization FiO2 <0.30. In preterm infants ≥28 weeks' GA enrolled in a randomized, controlled trial, lower GA and higher FiO2 before randomization predicted early nHF treatment failure. Infants were more likely to be successfully treated with nHF from soon after birth if they were born at ≥30 weeks GA and had a prerandomization FiO2 <0.30. However, even in this select population, continuous positive airway pressure remains superior to nHF as early respiratory support in preventing treatment failure. Australian New Zealand Clinical Trials Registry: ACTRN12613000303741.

Effects of high-flow nasal oxygen vs noninvasive positive airway pressure in hypoxemic patients after surgery

Objective To prospectively investigate the effects of high-flow nasal oxygen on hypoxemic patients after surgery. Methods A total of 108 postoperation hypoxemic patients (150 mmHg≤PaO2/FiO2<300 mmHg, PaCO2≤50 mmHg) in Beijing Hospital Surgical Intensive Critical Unit was included and assigned randomly to two groups from June 2016 to April 2017. Fifty four patients (study group) who received high-flow nasal oxygen therapy were compared with 54 patients (control group) who received noninvasive ventilation therapy. The data of reintubation and mortality in 28 days after extubation were collected and analyzed. Results No significant differences were found for reintubation rate (11.1% vs 13.0%, P=0.767) and mortality (5.6% vs 7.4%, P=0.696) in 28 days after extubation between two groups. In subgroup analysis, no significant differences were found for different hypoxima level (250 mmHg≤PaO2/FiO2<300 mmHg, 200 mmHg≤PaO2/FiO2<250 mmHg and 150 mmHg≤PaO2/FiO2<200 mmHg) between two groups, for reintubation rate (0 vs 3.7%, P=0.296; 20% vs 14.3%, P=0.684; 30% vs 30.8%, P=0.968, respectively) and mortality (0 vs 3.7%, P=0.296; 6.7% vs 7.1%, P=0.960; 20% vs 15.4%, P=0.772, respectively). Face skin breakdown were significantly more common in control group (11.1% vs 0, P=0.012). Conclusions High-flow nasal oxygen therapy was not inferior to noninvasive ventilation for mild and moderate hypoxemic patients after surgery. High-flow nasal oxygen therapy is safe and effective for these patients. Key words: Oxygen inhalation therapy; Positive-pressure respiration; Anoxia/TH; Postoperative complications/TH

Nursing care of patients with lung transplantation patients receiving high flow nasal cannulae oxygen therapy during perioperative period

Objective To summarize the experiences of postoperative care of 7 patients with lung transplantation patients receiving high flow nasal cannulae oxygen therapy. Methods The key points to ensure the success of operation were oxygen therapy waiting for lung transplantation, sequential treatment after tracheal intubation, assisted by fiberoptic bronchoscopy, nasal high flow oxygen therapy failed to switch to non-invasive treatment or re intubation. Results All 7 patients got through the intensive care period successful. Conclusions High flow nasal cannulae can improve the comfort and compliance of lung transplant patients, and easy to operate. Key words: Nursing care; Lung transplantation; High flow nasal cannulae oxygen therapy

A study on the effects and safety of sequential humidified high flow nasal cannula oxygenation therapy on the COPD patients after extubation

Objective: To investigate and compare the effect and safety of nasal high-flow oxygen therapy (HFNCO) and noninvasive ventilation (NIV) therapy after extubation in patients with chronic obstructive pulmonary disease (COPD). Methods: All COPD patients subjected to mechanical ventilation in the Emergency Intensive Unit of the First Affiliated Hospital of Zhejiang University during January 2015 to June 2016 were included in the study. The patients were divided into two groups after extubation and HFNCO and NIV were adopted on each group respectively. Clinical indexes including the patients' general condition, blood gas analysis and pulmonary function before and after extubation, ratio of re-intubation and CT grades were collected and analyzed. Results: There was no significant difference in the incidence of aspiration (4.8% vs 8.3%), pressure sores (0 vs 8.3%) and delirium (4.8% vs 12.5%) between the two groups (all P>0.05). At 12 h after extubation, the oxygenation index of NIV group was significantly higher than that of the HFNCO group (265±29 vs 297±33; P<0.05), while no significant difference in PCO(2) (P>0.05). For 24 h and 72 h after extubation, there was no statistically significant difference in oxygenation index and PCO(2) between the both groups (P>0.05). The intensive care unit (ICU) retention time in HFNCO group was significantly lower than that in NIV group (13.7±0.8 vs 15.2±0.5; P<0.05). In addition, no significant difference between the two groups in mortality and re-intubation rate at 28 d (P>0.05) was observed. Conclusion: HFNCO is effective and safe in the treatment of COPD patients after extubation, and it is hence valuable for further clinical application.

Nasal high-flow therapy in infants and children

This review highlights and summarizes the current evidence and knowledge of nasal high flow therapy management in infants and children. This review outlines the distinct differences in the use of NHF therapy between children and adults. A comprehensive literature review has been performed reviewing the relevant physiological studies and current evidence of support measures in these children. Despite the quick uptake of nasal high flow therapy in the clinical area there has been limited high-grade evidence, with new studies showing beneficial results with the use of nasal high flow therapy in acute respiratory disease and children.

Sleep Quality for Patients Receiving Noninvasive Positive Pressure Ventilation and Nasal High-Flow Oxygen Therapy in an ICU: Two Case Studies

Aim: The purpose of this case study was to examine the sleep quality of patients receiving noninvasive positive pressure ventilation (NPPV) or nasal high-flow oxygen therapy (NHF) in an intensive care unit and to investigate what types of nursing support are offered to such patients. Methods: We examined one patient each for NPPV and NHF. Polysomnography (PSG), review of the patient charts, and semi-structured interviews were used to collect the data for analysis. Results: Patients treated with NPPV or NHF demonstrated a noticeable reduction in deep sleep, with most of their sleep being shallow. Their sleep patterns varied greatly from those of healthy individuals. These results suggest that, in addition to experiencing extremely fragmented sleep, sleep in these patients was more likely to be interrupted by nursing interventions, such as during auscultation of breath sounds. Furthermore, it was revealed that “anxiety or discomfort that accompanies the mask or air pressure” in patients treated with NPPV and “discomfort that accompanies the nasal cannula or NHF circuit” in patients treated with NHF may be primary causes of disrupted sleep. Our results suggest a need for nursing care aimed at improving sleep quality in patients treated with NPPV or NHF.

436 The value of high flow nasal cannula oxygen therapy in paediatric patients with bronchiolitis: a closer look at the literature

Purpose of studyHigh flow oxygen (HFO) has been used more commonly as supportive treatment of paediatric patients with bronchiolitis. The objective of this study is to determine if HFO use on the patients admitted to the inpatient wards leads to reduction in paediatric intensive care unit (PICU) adm

Nasal high-flow oxygen therapy improves arterial oxygenation during one-lung ventilation in non-intubated thoracoscopic surgery.

Intraoperative hypoxaemia during one-lung ventilation (OLV) remains a major concern in thoracic surgery. Non-intubated video-assisted thoracic surgery (VATS) involves a greater risk of consequent emergent conversion to endotracheal intubation. Transnasal humidified rapid-insufflation ventilatory exchange (THRIVE) has recently been reported to be beneficial for higher oxygen reserves during difficult intubations and for enhancing postoperative recovery after thoracic surgery. However, the effects of THRIVE on oxygenation and carbon dioxide elimination before and during OLV in non-intubated VATS have not been investigated. Between September 2016 and October 2016, 30 patients underwent non-intubated VATS for lung tumour and were maintained with THRIVE at a flow of 20 l/min. These patients were compared with a historical control group comprising 30 patients who were maintained with oxygen masks at an oxygen flow of 10 l/min using a propensity score matching algorithm between September 2015 and July 2016. The preoperative arterial oxygen tension was significantly higher in patients maintained with THRIVE than it was in patients maintained with oxygen masks (mean 416.0 vs 265.9 mmHg, P < 0.01). During OLV, arterial oxygen tension remained significantly higher in the THRIVE group than in the oxygen mask group (mean 207.0 vs 127.8 mmHg, P = 0.01). The arterial carbon dioxide tension was comparable before and during OLV. The results indicated that THRIVE effectively increases the oxygen reserve both during OLV and after anaesthesia. Furthermore, non-intubated VATS is safer if THRIVE with flow adjustment is incorporated into a minimally invasive surgical approach, although carbon dioxide elimination is not facilitated.

Nasal high flow therapy in very low birth weight infants with mild respiratory distress syndrome: a single center experience

BackgroundPulmonary disorders and respiratory failure represent one of the most common morbidities of preterm newborns admitted to neonatal intensive care units (NICUs). The use of nasal high-flow therapy (nHFT) has been more recently introduced into the NICUs as a non-invasive respiratory (NIV) support.MethodsWe performed a retrospective study to evaluate safety and effectiveness of nHFT as primary support for infants born < 29 weeks of gestation and/or VLBW presenting with mild Respiratory Distress Syndrome (RDS).The main outcome was the percentage of patients that did not need mechanical ventilation. Secondary outcomes were rate of bronchopulmonary dysplasia (BDP), air leaks, nasal injury, late onset sepsis (LOS), intraventricular hemorrhage (IVH), retinopathy (ROP), necrotizing enterocolitis (NEC), hemodynamically-significant patent ductus arteriosus (PDA) and death.ResultsSixty-four preterm newborns were enrolled. Overall, 93% of enrolled patients did not need mechanical ventilation. In a subgroup analysis, 88.5% of infants < 29 weeks and 86.7% of infants ELBW (< 1000 g BW) did not need mechanical ventilation.BPD was diagnosed in 26.6% of preterms enrolled (Mild 20%, Moderate 4.5%, Severe 1.5%). In subgroup analysis, BPD was diagnosed in 53.9% of newborns with GA < 29 weeks, in 53.3% of ELBW newborns and in 11.1% of small for gestational age (SGA) newborns.Neither air leaks nor nasal injury were recorded as well as no exitus occurred. LOS, IVH, ROP, NEC and PDA occurred respectively in 16.1%, 0%, 7.8%, and 1.6% of newborns.ConclusionsAccording to our results, n-HFT seems to be effective as first respiratory support in preterm newborns with mild RDS. Further studies in a larger number of preterm newborns are required to confirm nHFT effectiveness in the acute phase of RDS.

Clinical effects of high flow nasal cannula oxygen therapy in post-extubation intensive care unit patients:a systematic review

Objective To evaluate the clinical effects of heated humidified high flow nasal cannula oxygen therapy on post-extubation intensive care unit (ICU) patients. Methods A computerized search was performed through Cochrane Library, EMBASE, PubMed, Elsevier, CNKI, Wanfang Database, SinoMed for randomized controlled trial(RCTs) which studied the effects of clinical effects of heated humidified high flow nasal cannula oxygen therapy on post-extubation ICU patients. Two reviewers separately searched the articles, evaluated the quality of the literatures, extracted date according to the inclusion and exclusion criteria. RevMan5.3 was used for Meta-analysis. Results Five RCTs were included involving 982 patients in the study. The results of meta-analysis showed that the HFNC group was lower than COT group on the re-intubation rate (OR=0.39, 95%CI 0.25-0.62, P 0.05) on post-extubation respiratory failure (OR=0.85, 95%CI 0.35-2.09), respiratory infection (OR=0.69, 95%CI 0.36-1.34), hospital length of stay (MD=0.51, 95%CI-0.02-1.03), mortality of hospital (OR=0.81, 95%CI 0.39-1.69). Conclusions The use of HFNC oxygen therapy can reduce there-intubation rate, improve oxygenation index, comfort level and tolerance on post-extubation ICU patients, while HFNC group has no significant impact on the post-extubation respiratory failure, respiratory infection, hospital length of stay, mortality of hospital compared with COTgroup. However, in view of the quantity and quality of study. More RCTs should be conducted to verify the results. Key words: Complication; Meta-analysis; Heated humidified high flow nasal cannula oxygen therapy; Post-extubation

Nasal injury in preterm infants receiving non-invasive respiratory support: a systematic review

ObjectiveBinasal prongs are the most commonly used interface for the delivery of nasal positive airway pressure (CPAP) to preterm infants. However, they are associated with pressure-related nasal injury, which causes...

Nasal high flow therapy and PtCO2 in stable COPD: A randomized controlled cross-over trial.

Hypercapnia is associated with worse clinical outcomes in exacerbations of COPD. The present study aimed to determine the effects of nasal high flow (NHF) therapy on transcutaneous partial pressure of carbon dioxide (PtCO2 ) in stable COPD patients. In a single-blind randomized controlled cross-over trial, 48 participants with COPD were allocated in random order to all of four 20 min interventions: NHF at 15 L/min, 30 L/min and 45 L/min or breathing room air with each intervention followed by a washout period of 15 min. The primary outcome measure was PtCO2 at 20 min, adjusted for baseline PtCO2 . Secondary outcomes included respiratory rate at 20 min, adjusted for baseline. The mean (95% CI) change in PtCO2 at 20 min was -0.6 mm Hg (-1.1 to 0.0), P = 0.06; -1.3 mm Hg (-1.9 to 0.8), P < 0.001; and -2.4 mm Hg (-2.9 to -1.8), P < 0.001; for NHF at 15 L/min, 30 L/min and 45 L/min compared with room air, respectively. The mean (95% CI) change in respiratory rate at 20 min was -1.5 (-2.7 to -0.3), P = 0.02; -4.1 (-5.3 to -2.9), P < 0.001; and -4.3 (-5.5 to -3.1), P < 0.001; breaths per minute compared with room air, respectively. NHF results in a small flow-dependent reduction in PtCO2 and respiratory rate in patients with stable COPD.

Ten important articles on noninvasive ventilation in critically ill patients and insights for the future: A report of expert opinions

BackgroundNoninvasive ventilation is used worldwide in many settings. Its effectiveness has been proven for common clinical conditions in critical care such as cardiogenic pulmonary edema and chronic obstructive pulmonary disease exacerbations.Since the first pioneering studies of noninvasive ventilation in critical care in the late 1980s, thousands of studies and articles have been published on this topic. Interestingly, some aspects remain controversial (e.g. its use in de-novo hypoxemic respiratory failure, role of sedation, self-induced lung injury). Moreover, the role of NIV has recently been questioned and reconsidered in light of the recent reports of new techniques such as high-flow oxygen nasal therapy.MethodsWe conducted a survey among leading experts on NIV aiming to 1) identify a selection of 10 important articles on NIV in the critical care setting 2) summarize the reasons for the selection of each study 3) offer insights on the future for both clinical application and research on NIV.ResultsThe experts selected articles over a span of 26 years, more clustered in the last 15 years. The most voted article studied the role of NIV in acute exacerbation chronic pulmonary disease. Concerning the future of clinical applications for and research on NIV, most of the experts forecast the development of innovative new interfaces more adaptable to patients characteristics, the need for good well-designed large randomized controlled trials of NIV in acute “de novo” hypoxemic respiratory failure (including its comparison with high-flow oxygen nasal therapy) and the development of software-based NIV settings to enhance patient-ventilator synchrony.ConclusionsThe selection made by the experts suggests that some applications of NIV in critical care are supported by solid data (e.g. COPD exacerbation) while others are still waiting for confirmation. Moreover, the identified insights for the future would lead to improved clinical effectiveness, new comparisons and evaluation of its role in still “lack of full evidence” clinical settings.

The Effect of High-Flow Nasal Cannula Oxygen Therapy in Acute Respiratory Failure: A Systematic Review

Objective To assess the efficacy, comfort and tolerability of high-flow nasal cannula oxygen therapy in patients with acute respiratory failure(ARF). Methods The literature of RCTs concerning high-flow nasal cannula(HFNC) versus usual oxygen care(UOC) in ARF patients was searched using the national and international electronic databases. All relevant studies were screened according to inclusion and exclusion criteria, and then the included studies were evaluated, and finally, the extracted data were analyzed using Rev Man 5.3 software provided by the Cochrane Collaboration. Results eleven RCTs were included in 3 170 patients, of those 1 550 patients were in HFNC group, while 1 620 patients were in UOC group.There was no statistical difference in mortality among in HFNC and UOC group (OR=0.92, 95%CI: 0.70-1.2, P=0.53), neither was the incidence of nosocomial infection (OR=0.85, 95%CI: 0.63-1.15, P=0.3). The incidence of endotracheal intubation was lower in HFNC group than in UOC group.The comfort and tolerablity was greater in HFNC group than that in UOC group. Conclusions No difference in mortality or nosocomial infection was detected in patients with ARF treated with HFNC compared with UOC. However, HFNC seem well tolerated by patients and showed a lower rate of endotracheal intubation . Key words: High-flow nasal cannula oxygen therapy; Respiratory failure; Randomized controlled trial; Mortality; Incidences of intubation