Project description:BACKGROUND:Postextubation high-flow nasal cannula (HFNC) is used as a support therapy in high-risk patients in ICU. This study aimed to determine the effects of HFNC therapy on lung recruitment and overdistension assessed by electrical impedance tomography (EIT). METHODS:Twenty-four patients who received HFNC within 24?h after extubation were prospectively enrolled in this study. EIT was used to monitor regional lung ventilation distributions at baseline (conventional oxygen therapy) and three flow rate levels of HFNC therapy (20, 40, and 60?L/min). Change of end-expiratory lung impedance (?EELI), regional recruitment (recruited-pixels) and overdistension (overdistended-pixels), and lung strain change were determined by EIT. EIT images were equally divided into four ventral-to-dorsal horizontal regions of interest (ROIs 1, 2, 3, and 4). "Overdistension-by HFNC" due to HFNC is defined as an increase of overdistened-pixels >?10 than baseline. Patients were divided into two groups: (1) high potential of recruitment (HPR), recruited-pixels >?10 pixels at 60?L/min than baseline, and (2) low potential of recruitment (LPR), recruited-pixels <?10 pixels at 60?L/min than baseline. RESULTS:When the flow rate gradually increased from baseline to 60?L/min, a significant and consistent increasing trend of global ?EELI (%) (p?<?0.0001), recruited-pixels (p?<?0.001), and overdistended-pixels (p?=?0.101) was observed. Moreover, the increase of ?EELI was mainly distributed in ROI2 (p?=?0.001) and ROI3 (p?<?0.0001). The HPR group (13/24 patients) had significantly higher recruited-pixels than the LPR group (11/24 patients) at 20, 40, and 60?L/min. There were no significant differences in PaO2/FiO2, ?EELI (%), and overdistention pixels between the two groups. The HPR group had 13 patients in which no one had "overdistension-by HFNC", and the LPR group had 11 patients in which 4 patients had "overdistension-by HFNC" (0/13 vs. 4/11, p?=?0.017). CONCLUSIONS:Using EIT could identify diverse effects of HFNC on lung regional ventilation in postextubation situations. Further study is required to validate using "HFNC effect" based on lung recruitment and overdistension by EIT in clinical practice. TRIAL REGISTRATION:The study was retrospectively registered at www.clinicaltrials.gov (no. NCT04245241).
Project description:BACKGROUND:Extubation failure is associated with increased morbidity and mortality, but cannot be safely predicted or avoided. High-flow nasal cannula (HFNC) prevents postextubation respiratory failure in low-risk patients. OBJECTIVE:To demonstrate that HFNC reduces postextubation respiratory failure in high-risk non-hypercapnic patients compared with conventional oxygen. METHODS:Randomized, controlled multicenter trial in patients who passed a spontaneous breathing trial. We enrolled patients meeting criteria for high-risk of failure to randomly receive HFNC or conventional oxygen for 24 h after extubation. Primary outcome was respiratory failure within 72-h postextubation. Secondary outcomes were reintubation, intensive care unit (ICU) and hospital lengths of stay, and mortality. Statistical analysis included multiple logistic regression models. RESULTS:The study was stopped due to low recruitment after 155 patients were enrolled (78 received high-flow and 77 received conventional oxygen). Groups were similar at enrollment, and all patients tolerated 24-h HFNC. Postextubation respiratory failure developed in 16 (20%) HFNC patients and in 21 (27%) conventional patients [OR 0.69 (0.31-1.54), p = 0.2]. Reintubation was needed in 9 (11%) HFNC patients and in 12 (16%) conventional patients [OR 0.71 (0.25-1.95), p = 0.5]. No difference was found in ICU or hospital length of stay, or mortality. Logistic regression models suggested HFNC [OR 0.43 (0.18-0.99), p = 0.04] and cancer [OR 2.87 (1.04-7.91), p = 0.04] may be independently associated with postextubation respiratory failure. CONCLUSION:Our study is inconclusive as to a potential benefit of HFNC over conventional oxygen to prevent occurrence of respiratory failure in non-hypercapnic patients at high risk for extubation failure. Registered at Clinicaltrials.gov NCT01820507.
Project description: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.
Project description:BackgroundUse of a high-flow nasal cannula (HFNC) reduced postextubation respiratory failure (PERF) and reintubation rate compared to use of a low-flow oxygen system (LFOS) in low-risk patients. However, no obvious conclusion was reached for high-risk patients. Here, we sought to present the current status of HFNC use as adjunctive oxygen therapy in a clinical setting and to elucidate the nature of the protective effect following extubation.MethodsThe medical records of 855 patients who were admitted to the intensive care unit of single university hospital during a period of 5.5 years were analyzed retrospectively, with only 118 patients ultimately included in the present research. The baseline characteristics of these patients and the occurrence of PERF and reintubation along with physiologic changes were analyzed.ResultsEighty-four patients underwent HFNC, and the remaining 34 patients underwent conventional LFOS after extubation. Physicians preferred HFNC to LFOS in the face of high-risk features including old age, neurologic disease, moderate to severe chronic obstructive pulmonary disease, a long duration of mechanical ventilation, low baseline arterial partial pressure of oxygen to fraction of inspired oxygen ratio, and a high baseline alveolar-arterial oxygen difference. The reintubation rate at 72 hours after extubation was not different (9.5% vs. 8.8%; P=1.000). Hypoxic respiratory failure was slightly higher in the nonreintubation group than in the reintubation group (31.9% vs. 6.7%; P=0.058). Regarding physiologic effects, heart rate was only stabilized after 24 hours of extubation in the HFNC group.ConclusionsNo difference was found in the occurrence of PERF and reintubation between both groups. It is worth noting that similar PERF and reintubation ratios were shown in the HFNC group in those with certain exacerbating risk factors versus not. Caution is needed regarding delayed reintubation in the HFNC group.
Project description:High-flow nasal cannula (HFNC) oxygen therapy comprises an air/oxygen blender, an active humidifier, a single heated circuit, and a nasal cannula. It delivers adequately heated and humidified medical gas at up to 60 L/min of flow and is considered to have a number of physiological effects: reduction of anatomical dead space, PEEP effect, constant fraction of inspired oxygen, and good humidification. While there have been no big randomized clinical trials, it has been gaining attention as an innovative respiratory support for critically ill patients. Most of the available data has been published in the neonatal field. Evidence with critically ill adults are poor; however, physicians apply it to a variety of patients with diverse underlying diseases: hypoxemic respiratory failure, acute exacerbation of chronic obstructive pulmonary disease, post-extubation, pre-intubation oxygenation, sleep apnea, acute heart failure, patients with do-not-intubate order, and so on. Many published reports suggest that HFNC decreases breathing frequency and work of breathing and reduces needs of escalation of respiratory support in patients with diverse underlying diseases. Some important issues remain to be resolved, such as its indication, timing of starting and stopping HFNC, and escalating treatment. Despite these issues, HFNC oxygen therapy is an innovative and effective modality for the early treatment of adults with respiratory failure with diverse underlying diseases.
Project description:BackgroundLiberation and extubation are important for patients supported by mechanical ventilation. Extubation success is related to the duration of an intensive care unit (ICU) stay and mortality rate. High-flow nasal cannula (HFNC) oxygen therapy has physiological and clinical benefits in respiratory care. The present study compared clinical outcomes associated with HFNC and conventional oxygen therapy (COT) among patients at high risk for reintubation.MethodsA single-center randomized clinical trial was conducted between March 2018 and June 2019. Sixty adults admitted to the ICU and who were at high-risk of reintubation and met the inclusion criteria were enrolled in this study. "High risk" for reintubation was defined as having at least one of the following risk factors: age > 65 years, Acute Physiology and Chronic Health Evaluation II score > 12 points on extubation day, obesity, poor expectoration, airway patency problems, difficult or prolonged weaning, and more than one comorbidity. The primary outcome of interest was reintubation within 72 hours. Secondary outcomes included duration of ICU and hospital stay, mortality rate, and time to reintubation.ResultsOf 60 patients, 31 received HFNC and 29 received COT (mean age, 78 ± 7.8 vs. 76 ± 6.5 years, respectively). Reintubation rate within 72 hours did not differ between the groups (3 patients [9.7%] vs. 1 patient [3.4%], respectively). Reintubation time was shorter among patients who received COT than among patients who received HFNC (0.5 hour vs. 25 hours), but this difference was not statistically significant. Duration of ICU did not differ between the groups (14.7 ± 9.6 days vs. 13.8 ± 15.7 days, for HFNC and COT, respectively).ConclusionAmong patients at high risk for reintubation, compared with COT, HFNC did not reduce the risk of reintubation within 72 hours.
Project description:IntroductionHeated high-flow nasal cannula (HHFNC) therapy for bronchiolitis has become increasingly prevalent without evidence that this therapy impacts patient outcomes. Lack of criteria for appropriate use may lead to overutilization, resulting in increased costs without patient benefit. Our primary aim was to decrease use of HHFNC in patients with bronchiolitis over one season.MethodsPatients with Bronchiolitis younger than 2 years of age admitted to the Hospital Medicine Service were included in this study. Using the model for improvement framework, we identified key drivers for HHFNC overuse and revised our bronchiolitis protocol to include low-flow nasal cannula trials before HHFNC initiation. We compared preintervention HHFNC utilization (December 2018-April 2019) with postintervention HFNC utilization (December 2019-March 2020).ResultsOne hundred ninety patients met inclusion criteria, 98 of them in the preintervention cohort and 92 in the postintervention cohort. Overall, the median age was 9 months and 65% of patients were male. Our HHFNC utilization rate decreased from 62% (61/98) to 43% (40/92) in the postintervention period. Our SPC analysis suggested special cause variation based on 7 points below the preintervention mean.ConclusionsThis QI intervention implementing a specified low-flow nasal cannula trial before the initiation of HHFNC shows promise in reducing overall HHFNC use. Future studies should focus on clear initiation and discontinuation criteria for HHFNC use in bronchiolitis.
Project description:Endoscopic retrograde cholangiopancreatography (ERCP) identifies and treats pancreatic and biliary diseases. We conducted a systematic review and meta-analysis examining relevant papers in five databases to examine the frequency of hypoxia throughout the surgery and the lowest oxygen saturation level in patients under sedation. Our meta-analysis included three randomized controlled trials with 390 participants, 196 in the high-flow oxygen (HFNC) group and 194 in the low-flow oxygen (LFNC) group. Their ages ranged from 65.3 to 79 years. The pooled effect estimate showed that HFNC decreased the incidence of hypoxia during the procedure when compared to LFNC (odds ratio -0.84; 95% confidence interval [CI] -1.65, -0.02; P = 0.04), and the mean of lowest oxygen saturation in patients during sedation was significantly lower in LFNC compared to HFNC (mean difference 2.34; 95% CI 1.35, 3.32; P = 0.001). The pooled effect estimate showed that the HFNC group had a lower incidence rate of jaw thrusting adverse events during anesthesia than the LFNC group (risk difference -0.12; 95% CI -0.21, -0.04; P = 0.001). In summary, HFNC systems reduced the incidence of hypoxia for patients undergoing ERCP and had a higher mean lowest oxygen saturation during sedation.
Project description:BackgroundHigh-flow nasal oxygen therapy (HFNC) may be an attractive first-line ventilatory support in COVID-19 patients. However, HNFC use for the management of COVID-19 patients and risk factors for HFNC failure remain to be determined.MethodsIn this retrospective study, we included all consecutive COVID-19 patients admitted to our intensive care unit (ICU) in the first (Mars-May 2020) and second (August 2020- February 202) French pandemic waves. Patients with limitations for intubation were excluded. HFNC failure was defined as the need for intubation after ICU admission. The impact of HFNC use was analyzed in the whole cohort and after constructing a propensity score. Risk factors for HNFC failure were identified through a landmark time-dependent cause-specific Cox model. The ability of the 6-h ROX index to detect HFNC failure was assessed by generating receiver operating characteristic (ROC) curve.Results200 patients were included: HFNC was used in 114(57%) patients, non-invasive ventilation in 25(12%) patients and 145(72%) patients were intubated with a median delay of 0 (0-2) days after ICU admission. Overall, 78(68%) patients had HFNC failure. Patients with HFNC failure had a higher ICU mortality rate (34 vs. 11%, p = 0.02) than those without. At landmark time of 48 and 72 h, SAPS-2 score, extent of CT-Scan abnormalities > 75% and HFNC duration (cause specific hazard ratio (CSH) = 0.11, 95% CI (0.04-0.28), per + 1 day, p < 0.001 at 48 h and CSH = 0.06, 95% CI (0.02-0.23), per + 1 day, p < 0.001 at 72 h) were associated with HFNC failure. The 6-h ROX index was lower in patients with HFNC failure but could not reliably predicted HFNC failure with an area under ROC curve of 0.65 (95% CI(0.52-0.78), p = 0.02). In the matched cohort, HFNC use was associated with a lower risk of intubation (CSH = 0.32, 95% CI (0.19-0.57), p < 0.001).ConclusionsIn critically-ill COVID-19 patients, while HFNC use as first-line ventilatory support was associated with a lower risk of intubation, more than half of patients had HFNC failure. Risk factors for HFNC failure were SAPS-2 score and extent of CT-Scan abnormalities > 75%. The risk of HFNC failure could not be predicted by the 6-h ROX index but decreased after a 48-h HFNC duration.