Sistemi di umidificazione con ossigenoterapia ad alti flussi
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Sistemi di umidificazione con ossigenoterapia ad alti flussi
Sistemi di umidificazione con ossigenoterapia ad alti flussi LA TERAPIA UMIDIFICANTE PRESUPPOSTI RAZIONALI E SISTEMI DI SOMMINISTRAZIONE PARMA, 14 maggio 2014 Matteo Manici Thanks to Ossigenoterapia nei reparti intensivi • L’ossigeno è uno dei farmaci più comunemente utilizzati nei reparti di medicina e nei reparti di terapia intensiva – Potenzialmente ogni paziente in reparto intensivo riceve ossigeno • L’ossigenoterapia è sempre la prima soluzione che si applica al paziente nell’ambito del trattamento respiratorio Ossigenoterapia CPAP/NIV Ventilazione Invasiva ed è l’elemento che determina se passare a trattamenti più intensivi o invasivi, come la NIV o la ventilazione meccanica. Sistemi di umidificazione con ossigenoterapia ad alti flussi Ossigenoterapia nei reparti intensivi Le tecniche per la gestione di questo farmaco non si sono evolute per anni Vi sono varietà di tecniche poichè ognuna ha delle limitazioni Flusso FiO2 inspirata Comfort / tolleranza Comunicazione/mangiare, bere • • Fino a 6 l/min Dal 25 al 30%, senza controllo Da OK a scarso OK 15 l/min Fino all’80%, senza controllo Da scarso a molto scarso Non possibile senza desaturare Le limitazioni sono poco conosciute e possono essere fonte di errore. Passare da una tecnica ad un’altra può ritardare l’efficacia del trattamento e portare ad un peggioramento delle condizioni. Sistemi di umidificazione con ossigenoterapia ad alti flussi Optiflow è più efficace dell’ossigenoterapia standard Superiore supporto respiratorio Controllo della FiO2 inspirata Lavaggio dello spazio morto anatomico Umidificazione riscaldata Pressione positiva Scambio gassoso migliorato Sistemi di umidificazione con ossigenoterapia ad alti flussi Comfort e Tolleranza Secrezioni diluite e migliore clearance Benefici dall’alto flusso Migliore capacità di ossigenazione Controllo FiO2 inspirata Maschera ossigeno basso flusso / Occhialino Ritchie 2011 Sistemi di umidificazione con ossigenoterapia ad alti flussi Benefici dall’alto flusso Migliore capacità di ossigenazione Controllo FiO2 inspirata Maschera ossigeno basso flusso / Occhialino Sistemi ad alto flusso Ritchie 2011 Parke 2011 Sistemi di umidificazione con ossigenoterapia ad alti flussi Benefici dall’alto flusso Migliore capacità di ossigenazione > Alto flusso attraverso cannule nasali Optiflow vs Maschere O2 Supporto respiratorio con alto flusso -Controllo preciso della FiO2 inspirata, da 21 a 100 %O2 - Fino a 100 %O2 reale inspirata: aumento della capacità di ossigenazione vs maschere O2 Controllo FiO2 inspirata Ossigenazione migliorata Ritchie 2011 Sistemi di umidificazione con ossigenoterapia ad alti flussi Benefici dall’alto flusso Lavaggio dello spazio morto anatomico Supporto respiratorio con alto flusso Lavaggio dello spazio morto anatomico Schneider 2013 Sistemi di umidificazione con ossigenoterapia ad alti flussi > Alto flusso fornito attraverso cannula nasale Optiflow: - Riduce il rebreathing della CO2 espirata. - Crea un serbatoio di gas freschi nello spazio nasofaringeo, pronto per la successiva ispirazione. Migliora lo scambio gassoso Benefici dall’alto flusso Pressione positiva Supporto respiratorio con alto flusso Alto flusso fornito attraverso cannula nasale Optiflow: -Crea una pressione positiva nelle vie aeree. -Con la bocca aperta la pressione è inferiore, ma rimane significativa rispetto alla maschera che non crea pressione. Pressione Positiva Parke 2009 Sistemi di umidificazione con ossigenoterapia ad alti flussi Benefici dall’alto flusso Pressione positiva > Pressione positiva generata con Optiflow : Supporto respiratorio con alto flusso - Aumenta il volume polmonare di fine espirazione - Aumenta il Tidal Volume - Migliora reclutamento alveolare - Limita i rischi di atelettasie Pressione positiva Corley 2011 Sistemi di umidificazione con ossigenoterapia ad alti flussi Migiora lo scambio gassoso Benefici da Umidificazione Ottimale Comfort, tolleranza, mobilità delle secrezioni Umidificazione riscaldata > Ottimale umidificazione riscaldata fornita a 37°C , 100 %RH : -Facilita la mobilità delle secrezioni -Rende la fisioterapia più efficiente Clearance secrezioni -Consente al paziente di bere, mangiare e parlare in modo confortevole -Riduce le interruzioni del trattamento Comfort e tolleranza Roca 2010 Hasani 2008 Rea 2010 -Generale miglioramento del comfort e tolleranza Sistemi di umidificazione con ossigenoterapia ad alti flussi Ossigenoterapia standard > può generare un progressivo aggravamento nel trattamento dell’ipossiemia Nessun fattore predittivo Inizio gestione paziente Ossigenoterapia standard Tachipnea, Dispnea Paziente ipossiemico > Efficacia terapeutica non riuscita? Paziente ipercapnico >> Ridotta probabilità di successo del trattamento Aumento del lavoro reapiratorio Insufficienza Respiratoria Affaticamento Sistemi di umidificazione con ossigenoterapia ad alti flussi Nessun fattore predittivo Optiflow > in "salvataggio“ per il progressivo aggravamento nel trattamento dell’ipossiemia ? Troppo tardi Nessun fattore predittivo Inizio gestione paziente Ossigenoterapia standard Tachipnea, Dispnea Paziente ipossiemico > Finestra d’efficacia terapeutica mancata? Paziente ipercapnico >> Riduzione probabilità riuscita del trattamento. Insufficienza Respiratoria Troppo Tardi ? Affaticamento Sistemi di umidificazione con ossigenoterapia ad alti flussi Aumento del lavoro reapiratorio Nessun fattore predittivo Optiflow > evita l’inizio del progressivo aggravamento nel trattamento dell’ipossiemia Scambio gassoso migliorato Inizio gestione paziente Probabilità di Ipercapnie limitate SUCCESSO aumentate Respirazione che rimane efficace Lavoro reapiratorio limitato Per tutti i pazienti Tachipnea, dispnea ridotte Paziente ipossiemico Affaticamento limitato Sistemi di umidificazione con ossigenoterapia ad alti flussi Benefici clinici ed economici Superiore supporto respiratorio Umidificazione riscaldata Comfort e tolleranza Minori fallimenti es. verso : NIV, intubazione* Controllo della FiO2 inspirata Ossigenazione migliorata Tachipnea ridotta Lavaggio dello spazio morto anatomico Degenza ridotta * Scambio gassoso migliorato Dispnea ridotta Pressione Positiva Minore lavoro respiratorio * 1 giorno in Rianimazione = 1.500 € (source : CRREA) 1 fallimento (intubazione) evitata = 5 giorni di rianimazione (+/-) >> Costo analogo ad un trattamento per 150 pazienti con Optiflow Riduzione costi* Benefici clinici ed economici Riduzione dell’escalation e del periodo di degenza Esempio concreto dell’Ospedale Bon Secours St. Francis, South Carolina USA: - 17 posti letto di terapia intensiva ICU Optiflow è stato utilizzato per ogni paziente trattato in O2 a partire dal 2010 Confronto anno precedente verso primo anno completo con utilizzo Optiflow Degenza (gg) Uso BiPAP (gg) Vent. meccanica (gg) - 9% - 4,5 gg - 45% - Durata media del soggiorno ospedaliero ridotta di 4.5 giorni = XX $/yr - Utilizzo della NIV ridotta del 45% che equivale a 1320 giorni = XX $/yr - Ventilazione invasiva ridotta del 9%, che equivale a 641 giorni = XX $/yr Sistemi di umidificazione con ossigenoterapia ad alti flussi Come utilizzare Optiflow ? Interfaccia nasale Optiflow codice OPT84x e circuito riscaldato F&P Umidificatore con generatore di flusso integrato F&P AIRVO 2 Alimentazione con flussimetro per O2 Sistemi di umidificazione con ossigenoterapia ad alti flussi Umidificatore F&P MR850 Alimentazione con miscelatore Blender Benefici clinici documentati Erogazione precisa di ossigeno Anaesth Intensive Care. 2011 Nov;39(6):1103-10. Evaluation of a humidified nasal high-flow oxygen system, using oxygraphy, capnography and measurement of upper airway pressures. Ritchie JE, Williams AB, Gerard C, Hockey H. Author information Critical Care Complex, Middlemore Hospital, Auckland, New Zealand. [email protected] Abstract In this study, we evaluated the performance of a humidified nasal high-flow system (Optiflow, Fisher and Paykel Healthcare) by measuring delivered FiO, and airway pressures. Oxygraphy, capnography and measurement of airway pressures were performed through a hypopharyngeal catheter in healthy volunteers receiving Optiflow humidified nasal high flow therapy at rest and with exercise. The study was conducted in a nonclinical experimental setting. Ten healthy volunteers completed the study after giving informed written consent. Participants received a delivered oxygen fraction of 0.60 with gas flow rates of 10, 20, 30, 40 and 50 l/minute in random order FiO2, F(E)O2, F(E)CO2 and airway pressures were measured. Calculation of FiO2 from F(E)O2 and F(E)CO2 was later performed. Calculated FiO2 approached 0.60 as gas flow rates increased above 30 l/minute during nose breathing at rest. High peak inspiratory flow rates with exercise were associated with increased air entrainment. Hypopharyngeal pressure increased with increasing delivered gas flow rate. At 50 l/minute the system delivered a mean airway pressure of up to 7.1 cm H20. We believe that the high gas flow rates delivered by this system enable an accurate inspired oxygen fraction to be delivered. The positive mean airway pressure created by the high flow increases the efficacy of this system and may serve as a bridge to formal positive pressure systems. PMID: 22165366 [PubMed - indexed for MEDLINE] Sistemi di umidificazione con ossigenoterapia ad alti flussi Benefici clinici documentati Alto flusso e basso livello di pressione di supporto Respir Care. 2011 Mar;56(3):265-70. doi: 10.4187/respcare.00801. Epub 2011 Jan 21. A preliminary randomized controlled trial to assess effectiveness of nasal high-flow oxygen in intensive care patients. Parke RL, McGuinness SP, Eccleston ML. Abstract OBJECTIVE: In a cardiothoracic and vascular intensive care unit, to compare nasal high-flow (NHF) oxygen therapy and standard high-flow face mask (HFFM) oxygen therapy in patients with mild to moderate hypoxemic respiratory failure. METHODS: In a prospective randomized comparative study, 60 patients with mild to moderate hypoxemic respiratory failure were randomized to receive NHF or HFFM. We analyzed the success of allocated therapy, noninvasive ventilation rate, and oxygenation. RESULTS: Significantly more NHF patients succeeded with their allocated therapy (P = .006). The rate of noninvasive ventilation in the NHF group was 3/29 (10%), compared with 8/27 (30%) in the HFFM group (P = .10). The NHF patients also had significantly fewer desaturations (P = .009). CONCLUSIONS: NHF oxygen therapy may be more effective than HFFM in treating mild to moderate hypoxemic respiratory failure. Comment in High-flow nasal cannula oxygen in critically ill adults: do the nose or lungs know there's a difference? Wattier BA, Ward JJ. Respir Care. 2011 Mar; 56(3):355-8. PMID:21255498 [PubMed - indexed for MEDLINE Sistemi di umidificazione con ossigenoterapia ad alti flussi Benefici clinici documentati Sistemi di umidificazione con ossigenoterapia ad alti flussi Benefici clinici documentati Alto flusso e basso livello di pressione di supporto Br J Anaesth. 2009 Dec;103(6):886-90. doi: 10.1093/bja/aep280. Epub 2009 Oct 20. Nasal high-flow therapy delivers low level positive airway pressure. Parke R, McGuinness S, Eccleston M. Author information Cardiothoracic and Vascular Intensive Care Unit, Level 4, Building 32, Auckland City Hospital, Private Bag 92024, Auckland, New Zealand. [email protected] Abstract BACKGROUND: The aim of this prospective study was to determine whether a level of positive airway pressure was generated in participants receiving nasal high flow (NHF) delivered by the Optiflow system (Fisher and Paykel Healthcare Ltd, Auckland, New Zealand) in a cardiothoracic and vascular intensive care unit (ICU). METHODS: Nasopharyngeal airway pressure was measured in 15 postoperative cardiac surgery adult patients who received both NHF and standard facemask therapy at a flow rate of 35 litre min(-1). Measurements were repeated in the open mouth and closed mouth positions. Mean airway pressure was determined by averaging the pressures at the peak of inspiration of each breath within a 1 min period, allowing the entire pressure profile of each breath to be included within the calculation. RESULTS: Low level positive pressure was demonstrated with NHF at 35 litre min(-1) with mouth closed when compared with a facemask. NHF generated a mean nasopharyngeal airway pressure of mean 2.7 cm H2O with the mouth closed. Airway pressure was significantly higher when breathing with mouth closed compared with mouth open (P<or=0.0001). CONCLUSIONS: This study demonstrated that a low level of positive pressure was generated with NHF at 35 liter min of gas flow. This is consistent with results obtained in healthy volunteers. Australian Clinical Trials Registry www.actr.org.au ACTRN012606000139572. PMID: 19846404 [PubMed - indexed for MEDLINE] PMCID: PMC2777940 Sistemi di umidificazione con ossigenoterapia ad alti flussi Benefici clinici documentati Aumento del volume polmonare, ritmi respiratori più bassi, minore WOB e ridotta dispnea Br J Anaesth. 2011 Dec;107(6):998-1004. doi: 10.1093/bja/aer265. Epub 2011 Sep 9. Oxygen delivery through high-flow nasal cannulae increase end-expiratory lung volume and reduce respiratory rate in post-cardiac surgical patients. Corley A, Caruana LR, Barnett AG, Tronstad O, Fraser JF. Author information Critical Care Research Group, The Prince Charles Hospital and University of Queensland, Rode Rd, Chermside, QLD 4032, Australia. [email protected] Abstract BACKGROUND: High-flow nasal cannulae (HFNCs) create positive oropharyngeal airway pressure, but it is unclear how their use affects lung volume. Electrical impedance tomography allows the assessment of changes in lung volume by measuring changes in lung impedance. Primary objectives were to investigate the effects of HFNC on airway pressure (P(aw)) and end-expiratory lung volume (EELV) and to identify any correlation between the two. Secondary objectives were to investigate the effects of HFNC on respiratory rate, dyspnoea, tidal volume, and oxygenation; and the interaction between BMI and EELV. METHODS: Twenty patients prescribed HFNC post-cardiac surgery were investigated. Impedance measures, P(aw), ratio, respiratory rate, and modified Borg scores were recorded first on low-flow oxygen and then on HFNC. RESULTS: A strong and significant correlation existed between P(aw) and end-expiratory lung impedance (EELI) (r=0.7, P<0.001). Compared with low-flow oxygen, HFNC significantly increased EELI by 25.6% [95% confidence interval (CI) 24.3, 26.9] and P(aw) by 3.0 cm H(2)O (95% CI 2.4, 3.7). Respiratory rate reduced by 3.4 bpm (95% CI 1.7, 5.2) with HFNC use, tidal impedance variation increased by 10.5% (95% CI 6.1, 18.3), and ratio improved by 30.6 mm Hg (95% CI 17.9, 43.3). A trend towards HFNC improving subjective dyspnoea scoring (P=0.023) was found. Increases in EELI were significantly influenced by BMI, with larger increases associated with higher BMIs (P<0.001). CONCLUSIONS: This study suggests that HFNCs reduce respiratory rate and improve oxygenation by increasing both EELV and tidal volume and are most beneficial in patients with higher BMIs. PMID: 21908497 [PubMed - indexed for MEDLINE] Sistemi di umidificazione con ossigenoterapia ad alti flussi Benefici clinici documentati Umidificazione ottimale – Migliore comfort e tolleranza Respir Care. 2010 Apr;55(4):408-13. High-flow oxygen therapy in acute respiratory failure. Roca O, Riera J, Torres F, Masclans JR. Author information Servei de Medicina Intensiva (Area General), Hospital Universitari Vall d'Hebron, Passeig Vall d'Hebron 119-129, 08035 Barcelona, Spain. [email protected] Abstract OBJECTIVE: To compare the comfort of oxygen therapy via high-flow nasal cannula (HFNC) versus via conventional face mask in patients with acute respiratory failure. Acute respiratory failure was defined as blood oxygen saturation < 96% while receiving a fraction of inspired oxygen > or = 0.50 via face mask. METHODS: Oxygen was first humidified with a bubble humidifier and delivered via face mask for 30 min, and then via HFNC with heated humidifier for another 30 min. At the end of each 30-min period we asked the patient to evaluate dyspnea, mouth dryness, and overall comfort, on a visual analog scale of 0 (lowest) to 10 (highest). The results are expressed as median and interquartile range values. RESULTS: We included 20 patients, with a median age of 57 (40-70) years. The total gas flow administered was higher with the HFNC than with the face mask (30 [21.3-38.7] L/min vs 15 [12-20] L/min, P < .001). The HFNC was associated with less dyspnea (3.8 [1.3-5.8] vs 6.8 [4.1-7.9], P = .001) and mouth dryness (5 [2.3-7] vs 9.5 [8-10], P < .001), and was more comfortable (9 [8-10]) versus 5 [2.3-6.8], P < .001). HFNC was associated with higher P(aO(2)) (127 [83-191] mm Hg vs 77 [64-88] mm Hg, P = .002) and lower respiratory rate (21 [18-27] breaths/min vs 28 [25-32] breaths/min, P < .001), but no difference in P(aCO(2)). CONCLUSIONS: HFNC was better tolerated and more comfortable than face mask. HFNC was associated with better oxygenation and lower respiratory rate. HFNC could have an important role in the treatment of patients with acute respiratory failure. Comment in Improved oxygenation and increased comfort: a great combination. [Respir Care. 2010]Improved oxygenation and increased comfort: a great combination.Anderson JM. Respir Care. 2010 Apr; 55(4):485. PMID: 20406507 [PubMed - indexed for MEDLINE] Sistemi di umidificazione con ossigenoterapia ad alti flussi Benefici clinici documentati Umidificazione ottimale e Clearance mucociliare Chron Respir Dis. 2008;5(2):81-6. doi: 10.1177/1479972307087190. Domiciliary humidification improves lung mucociliary clearance in patients with bronchiectasis. Hasani A, Chapman TH, McCool D, Smith RE, Dilworth JP, Agnew JE. Author information Department of Medical Physics, Royal Free Hospital, London, UK. [email protected] Abstract Inspired air humidification has been reported to show some benefit in bronchiectatic patients. We have investigated the possibility that one effect might be to enhance mucociliary clearance. Such enhancement might, if it occurs, help to lessen the risks of recurrent infective episodes. Using a radioaerosol technique, we measured lung mucociliary clearance before and after 7 days of domiciliary humidification. Patients inhaled high flow saturated air at 37 degrees C via a patient-operated humidification nasal inhalation system for 3 h per day. We assessed tracheobronchial mucociliary clearance from the retention of (99m)Tc-labelled polystyrene tracer particles monitored for 6 h, with a follow-up 24-h reading. Ten out of 14 initially recruited patients (age 37-75 years; seven females) completed the study (two withdrew after their initial screening and two prior to the initial clearance test). Seven patients studied were non-smokers; three were ex-smokers (1-9 pack-years). Initial tracer radioaerosol distribution was closely similar between pre- and post-treatment. Following humidification, lung mucociliary clearance significantly improved, the area under the tracheobronchial retention curve decreased from 319 +/- 50 to 271 +/- 46%h (p < 0.07). Warm air humidification treatment improved lung mucociliary clearance in our bronchiectatic patients. Given this finding plus increasing laboratory and clinical interest in humidification mechanisms and effects, we believe further clinical trials of humidification therapy are desirable, coupled with analysis of humidification effects on mucus properties and transport. PMID: 18539721 [PubMed - indexed for MEDLINE] Sistemi di umidificazione con ossigenoterapia ad alti flussi Benefici clinici documentati Riduce le riacutizzazioni dell’insufficienza respiratoria Respir Med. 2010 Apr;104(4):525-33. doi: 10.1016/j.rmed.2009.12.016. Epub 2010 Feb 9. The clinical utility of long-term humidification therapy in chronic airway disease. Rea H, McAuley S, Jayaram L, Garrett J, Hockey H, Storey L, O'Donnell G, Haru L, Payton M, O'Donnell K. Author information University of Auckland, Auckland, New Zealand. Abstract AIM: Persistent airway inflammation with mucus retention in patients with chronic airway disorders such as COPD and bronchiectasis may lead to frequent exacerbations, reduced lung function and poor quality of life. This study investigates if long-term humidification therapy with high flow fully humidified air at 37 degrees C through nasal cannulae can improve these clinical outcomes in this group of patients. METHOD: 108 patients diagnosed with COPD or bronchiectasis were randomised to daily humidification therapy or usual care for 12 months over which exacerbations were recorded. Lung function, quality of life, exercise capacity, and measures of airway inflammation were also recorded at baseline, 3 and 12 months. RESULTS: Patients on long-term humidification therapy had significantly fewer exacerbation days (18.2 versus 33.5 days; p = 0.045), increased time to first exacerbation (median 52 versus 27 days; p = 0.0495) and reduced exacerbation frequency (2.97/patient/year versus 3.63/patient/year; p = 0.067) compared with usual care. Quality of life scores and lung function improved significantly with humidification therapy compared with usual care at 3 and 12 months. CONCLUSION: Long-term humidification therapy significantly reduced exacerbation days, increased time to first exacerbation, improved lung function and quality of life in patients with COPD and bronchiectasis. Clinical trial registered with www.actr.org.au; Number ACTRN2605000623695. Copyright 2010 Elsevier Ltd. All rights reserved. PMID: 20144858 Clinical trial registered with www.actr.org.au; Number ACTRN2605000623695. Sistemi di umidificazione con ossigenoterapia ad alti flussi Benefici clinici documentati Riduzione ritmo respiratorio, minore WOB e ridotta dispnea Intensive Care Med. 2011 Nov;37(11):1780-6. doi: 10.1007/s00134-011-2354-6. Epub 2011 Sep 27. Beneficial effects of humidified high flow nasal oxygen in critical care patients: a prospective pilot study. Sztrymf B, Messika J, Bertrand F, Hurel D, Leon R, Dreyfuss D, Ricard JD. Author information Hôpital Louis Mourier, Service de Réanimation Médico-Chirurgicale, Colombes, France. Abstract PURPOSE: To evaluate the efficiency, safety and outcome of high flow nasal cannula oxygen (HFNC) in ICU patients with acute respiratory failure. METHODS:Pilot prospective monocentric study. Thirty-eight patients were included. Baseline demographic and clinical data, as well as respiratory variables at baseline and various times after HFNC initiation during 48 h, were recorded. Arterial blood gases were measured before and after the use of HFNC. Noise and discomfort were monitored along with outcome and need for invasive mechanical ventilation. RESULTS: HFNC significantly reduced the respiratory rate, heart rate, dyspnea score, supraclavicular retraction and thoracoabdominal asynchrony, and increased pulse oxymetry. These improvements were observed as early as 15 min after the beginning of HFNC for respiratory rate and pulse oxymetry. PaO(2) and PaO(2)/FiO(2) increased significantly after 1 h HFNC in comparison with baseline (141 ± 106 vs. 95 ± 40 mmHg, p = 0.009 and 169 ± 108 vs. 102 ± 23, p = 0.036; respectively). These improvements lasted throughout the study period. HFNC was used for a mean duration of 2.8 days and a maximum of 7 days. It was never interrupted for intolerance. No nosocomial pneumonia occurred during HFNC. Nine patients required secondary invasive mechanical ventilation. Absence of a significant decrease in the respiratory rate, lower oxygenation and persistence of thoracoabdominal asynchrony after HFNC initiation were early indicators of HFNC failure. CONCLUSIONS: HFNC has a beneficial effect on clinical signs and oxygenation in ICU patients with acute respiratory failure. These favorable results constitute a prerequisite to launching a randomized controlled study to investigate whether HFNC reduces intubation in these patients. PMID: 21946925 [PubMed - indexed for MEDLINE] Sistemi di umidificazione con ossigenoterapia ad alti flussi Benefici clinici documentati ATS 2014 [Poster Board # 823] Bilevel Positive Airway Pressure Versus OPTIFLOW In Hypoxemic Patients After Cardiothoracic Surgery (The BiPOP Study): A Multicenter, Randomized, Noninferiority, Open Trial [Publication Number: A6572] F. Stephan, M.D; Ph.D1, B. Barrucand, M.D2, P. Petit, M.D2, S. Rezaiguia-Delclaux, M.D1, A. Medard, M.D3, B. Delannoy, M.D4, B. Cosserand, M.D3, G. Flicoteaux, M.D2, A. Imbert, M.D1, C. Pilorge, M.D1, L. Berard, M.D5 1Le Plessis Robinson/FR, 2Besancon/FR, 3Clermond Ferrand/FR, 4Lyon/FR, 5Paris/FR The BiPOP Study RATIONALE: Occurrence of hypoxemic acute respiratory failure is frequent after cardiothoracic surgery. Noninvasive ventilation delivered as bilevel positive airway pressure (BiPAP) is an effective preventive and therapeutic tool to treat acute respiratory failure. Nasal high flow oxygen therapy (OPTIFLOW™) is an increasingly popular method to improve oxygenation. However, no clinical trials have confirmed that the improvement of gas exchange with OPTIFLOW™is similar to that obtained under BiPAP. We conducted a multicenter, randomized, non inferiority, open trial to compare the efficacy of OPTIFLOW™with BiPAP in the treatment of postoperative hypoxemia after cardiothoracic surgery. PATIENTS AND METHODS: Patients were included in the post operative period if they developed acute respiratory failure or they are considered at risk for respiratory failure after extubation. Patients were assigned to receive treatment with either OPTIFLOW™or BiPAP. The primary outcome was treatment failure defined by need for endotracheal intubation, switch to the other method, and premature stop. We estimated a treatment failure rate of 20%. For treatment with OPTIFLOW™ to be noninferior, the upper limit of the 95%-confidence interval (95%-CI) had to be below 9%. We determined that a sample of approximately 800 patients was required to show noninferiority for OPTIFLOW™ with a power of 80%. RESULTS: A total of 830 patients with similar baseline characteristics had been randomly assigned to either BiPAP (416 patients) or OPTIFLOW™ (414 patients). Inclusion for acute respiratory failure concerned 240 patients (57.7%) in the BiPAP group and 248 patients (59.9%) in the OPTIFLOW™ group (p = 0.52). The use of OPTIFLOW™ was noninferior to the use of BiPAP, with treatment failure occurring in 101 of 414 patients (24.4%) in the OPTIFLOW™ group and in 102 of 416 patients (24.5%) in the BiPAP group (risk difference, 0.12 percentage points; 95%-CI -5.89 – 6.13]). The mean time from beginning of therapy to treatment failure was similar in both group (1.9 ± 3.6 days in BiPAP group vs 2.0 ± 3.9 in OPTIFLOW™ group, p = 0.88). Infection occurred in114 patients in the BiPAP group (27.4%) and in 114 (27.5%) patients in the OPTIFLOW™ group (p = 0.95). The rate of death in the intensive care unit was 5.5% for patients in the BiPAP group and 6.8% for patients in the OPTIFLOW™ group (p = 0.48). CONCLUSION: The efficacy of OPTIFLOW™ was similar to that of BiPAP as respiratory support for patients with or at risk of acute respiratory failure after cardio thoracic surgery. (Clinical Trials.gov NCT01458444) Sistemi di umidificazione con ossigenoterapia ad alti flussi