High-Flow Nasal Cannula Oxygen Therapy versus Non-Invasive Ventilation in patients at very high risk for extubating failure: A systematic review of randomized controlled trials.

BACKGROUND: Mechanical ventilation is commonly used for managing respiratory failure in chronic obstructive pulmonary disease (COPD) patients, but weaning patients off ventilator support can be challenging and associated with complications. While many patients respond well to Non-invasive ventilation (NIV), a significant proportion may not respond as favourably. We aimed to assess whether high-flow nasal cannula (HFNC) is equally effective as NIV in reducing extubation failure among previously intubated COPD patients. METHODS: This systematic review was carried out in line with PRISMA guidelines We searched PubMed, Scopus, Web of Science, and Cochrane library from inception until February 15, 2023. Randomized Clinical Trials (RCTs) of adults at high risk for extubating failure were included. We examined the use of HFNC as the intervention and NIV as the comparator. Our outcome of interest included, reintubation rate, length of hospital or intensive care unit (ICU) stay, adverse events, and time to reintubation. The Cochrane risk-of-bias tool was used for randomized trials to assess risk of bias. RESULTS: We identified 348 citations, 11 of which were included, representing 2,666 patients. The trials indicate that HFNC is comparable to NIV in preventing reintubation after extubating in COPD patients. In comparison to NIV, HFNC also produced improved tolerance, comfort, and less complications such as airway care interventions. NIV with active humification may be more effective that HFNC in avoiding reintubation in patients who are at extremely high risk for extubating failure. CONCLUSION: The inconclusive nature of emerging evidence highlights the need for additional studies to establish the efficacy and suitability of HFNC as an alternative to NIV for previously intubated COPD patients. Clinicians should consider the available options and individualize their approach based on patient characteristics. Future research should focus on addressing these gaps in knowledge to guide clinical decision-making and optimize outcomes for this patient population.

Factors influencing the therapeutic failure of high-flow nasal cannula oxygen humidification in patients with interstitial pneumonia complicated by respiratory failure.

OBJECTIVE: The aim of this study was to explore the factors influencing the treatment failure of high-flow nasal cannula (HFNC) therapy in patients with interstitial pneumonia (IP) complicated by respiratory failure. PATIENTS AND METHODS: A total of 158 patients with IP and respiratory failure treated with HFNC in our hospital from January 2020 to August 2023 were selected as the study population. Based on treatment efficacy, they were categorized into the HFNC treatment failure group and the HFNC treatment success group. Clinical data were compared between the two groups. Multiple logistic regression analysis was employed to identify independent factors influencing treatment failure, and the predictive value of these factors for HFNC treatment failure was assessed using receiver operating characteristic (ROC) curve analysis. RESULTS: After 7 days of HFNC treatment, among the 158 patients with IP and respiratory failure, 25 (15.8%) declared treatment failure, while the remaining 133 (84.2%) showed treatment success. Patients in the HFNC treatment failure group had significantly higher age, duration of IP, pre-treatment respiratory rate, C-reactive protein (CRP), and controlling nutritional status (CONUT) scores compared to the HFNC treatment success group. The PaO2/FiO2 ratio, left ventricular ejection fraction, and Glasgow Coma Scale (GCS) were significantly lower in the HFNC treatment failure group (p<0.05). Multiple logistic regression analysis revealed that pre-treatment PaO2/FiO2 ratio, CRP, CONUT, and GCS scores were independent factors influencing HFNC treatment failure in patients with IP and respiratory failure (p<0.05). Lower PaO2/FiO2 ratio and GCS scores, and higher CRP and CONUT scores were associated with an increased risk of HFNC treatment failure. ROC curve analysis indicated that pre-treatment PaO2/FiO2 ratio, CRP, CONUT, and GCS scores in patients with IP and respiratory failure had a high predictive value for HFNC treatment failure (p<0.05). CONCLUSIONS: The HFNC failure rate in patients with IP and respiratory failure is 15.8%. Pre-treatment PaO2/FiO2 ratio, CRP, CONUT, and GCS scores are independent factors associated with HFNC treatment failure and warrant clinical attention.

High-flow nasal cannula during pulmonary rehabilitation for people with chronic obstructive pulmonary disease: A systematic review and meta-analysis.

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is an increasingly concerning global public health issue due to its high burden of morbidity and mortality. Pulmonary rehabilitation (PR) is a comprehensive intervention to improve patients' physical and psychological conditions, commonly involving oxygen supplementation. The potential benefits of high-flow nasal cannula (HFNC) have recently sparked interest as oxygen therapy. In this context, this study aims to assess the effects of HFNC during the exercise training component of a PR program in people with COPD. METHODS: Systematic review (CRD42022330929). We included randomised controlled trials (RCTs), including crossover RCTs with adults with stable COPD. We included trials using oxygen therapy with HFNC during the exercise training component of a PR programme. PRIMARY OUTCOMES: disease-specific health-related quality of life (HRQoL), exercise capacity (EC) and adverse events. SECONDARY OUTCOMES: treatment adherence, breathlessness and future exacerbations. RESULTS: We included five studies with 300 participants with moderate to severe COPD. The certainty of the evidence was primarily low or very low for all outcomes of interest due to risk of bias, inconsistency or imprecision. HFNC has little to no difference in HRQoL (4 studies, 129 participants, MD 0.17, 95% CI -1.20 to 1.54; I2 50%). HFNC may result in little to no difference in EC (3 studies, 212 participants, mean difference 18.73, 95% CI -20.49 to 28.94; I2 56%), and we are uncertain about the effect of HFNC on breathlessness (4 studies; 244 participants, MD of -0.07, 95% CI -0.4 to 0.26; I2 63%). Only one study with 44 participants reported a participant's withdrawal because of progressive dyspnoea during lower limb exercise. CONCLUSIONS: We are uncertain about the effect of HFNC during the exercise component of a PR programme in HRQoL, EC or dyspnoea compared to usual care or conventional supplementary oxygen. Non-domiciliary oxygen patients showed improvements in HRQoL, EC and dyspnoea.

Effect of Nasal Continuous Positive Airway Pressure on Retinopathy of Prematurity in Preterm Newborns: A Comparative Analysis with Mechanical Ventilation and High-Flow Nasal Cannula Therapy.

BACKGROUND Retinopathy of prematurity (ROP), originally described as retrolental fibroplasia, represents an abnormal growth of blood vessels in the premature retina that can occur in response to oxygen therapy. The association between ROP and invasive mechanical ventilation has been widely studied in the literature; however, the relationships between different types of ventilation and ROP have not been as well documented. This study aimed to compare the association of ROP incidence with mechanical ventilation (MV), nasal continuous positive airway pressure (nCPAP), and high-flow nasal cannula (HFNC) therapies in 130 pre-term infants with gestational ages <32 weeks. MATERIAL AND METHODS The study includes 130 premature newborns, out of which 54 underwent MV therapy, either alone or in combination with nCPAP or HFNC therapy, 63 underwent nCPAP therapy, either alone or in combination with MV or HFNC therapy, and 23 underwent HFNC therapy, either alone or in combination with MV or nCPAP therapy. The relationships between ROP and the 3 types of ventilation were analyzed by univariate followed by multivariate logistic regression. RESULTS When adjusting for covariates, only nCPAP and birth weight were significantly associated with ROP, the former being a strong risk factor, with an adjusted odds ratio (AOR) of 7.264 (95% CI, 2.622-20.120; P<0.001), and the latter being a weak protective factor, with an AOR of 0.998 (95% CI, 0.996-0.999; P<0.05). CONCLUSIONS The results showed nCPAP was a strong ROP risk factor, birth weight was a weak ROP protective factor, and MV and HFNC were not significantly associated with increased ROP risk.

High-Flow Nasal Oxygen versus Conventional Nasal Cannula in Preventing Hypoxemia in Elderly Patients Undergoing Gastroscopy with Sedation: A Randomized Controlled Trial.

Background: We aimed to compare the prevention of hypoxemia using High-flow nasal oxygen (HFNO) or regular nasal tubing (CNC) in elderly patients undergoing gastroscopy with sedation. Methods: This study was a prospective, randomized, controlled trial conducted at a single center. We included elective patients aged 65 and above who were undergoing gastroscopy with sedation. In the intervention group (HFNO), we set the oxygen flow rate to 60 liters per minute with an oxygen fraction (FiO2) of 0.6, while in the control group (CNC), it was 6 liters per minute. The primary outcome was the occurrence of hypoxemia (defined as Spo2 < 90%). Results: A total of 125 participants were enrolled (HFNO group: n = 63; CNC group: n = 62). The occurrence of hypoxemia was found to be significantly lower in the HFNO group compared to the CNC group (3.2% vs. 22.6%, p = 0.001). Additionally, a significantly shorter duration of low oxygen levels was observed in the HFNO group [0.0 seconds (0.0-13.0)] compared to the CNC group [0.0 seconds (0.0-124.0), p<0.001]. Moreover, a higher minimum Spo2 value was achieved in the HFNO group [99.0% (98.0-100.0) vs. 96.5% (91.0-99.0), p < 0.001], and a shorter recovery time was recorded [0.5 minutes (0.0-0.5) vs. 0.5 minutes (0.0-1.0), p = 0.016] in comparison to the CNC group. There were no differences in terms of comfort level [0 (0-4) vs. 0 (0-5), p = 0.268] between the two groups. Conclusions: The HFNO system was determined to be a safe and highly effective method for oxygen delivery, leading to a reduction in the occurrence of hypoxemia in elderly patients undergoing gastroscopy with sedation. It is recommended that HFNO be considered as the standard approach for management in this population.

Home-based respiratory support.

This review provides an overview of home-based respiratory support modalities for patients with chronic lung diseases. It discusses the increasing use of long-term high-flow nasal cannula (LT-HFNC) and long-term non-invasive ventilation (LT-NIV) and their potential to enhance patient quality of life. This review addresses various types of respiratory failure and their respective treatments, emphasising the significance of monitoring and telemedicine in home care. This comprehensive review underscores the clinical relevance of these interventions in the management of chronic lung diseases.

Optimal flow of high-flow nasal cannula oxygenation to prevent desaturation during sedation for bronchoscopy: a randomized controlled study.

BACKGROUND: Although high-flow nasal cannula (HFNC) oxygenation is currently recommended to prevent desaturation during sedation for bronchoscopy, there is no consensus on an optimal flow rate. OBJECTIVE: To determine the optimal oxygen flow rate for HFNC to effectively prevent desaturation during sedation for bronchoscopy. DESIGN: Prospective, randomized, and controlled study. METHODS: Patients (n = 240) scheduled for bronchoscopy were randomized to receive HFNC with propofol sedation (fraction of inspired oxygen, 100%) at one of six flow rates of 10, 20, 30, 40, 50, and 60 L/min, designated as groups 1-6, respectively. RESULTS: The incidence of desaturation significantly decreased by increasing the oxygen flow rate (42.5%, 17.5%, 15%, 10%, 2.5%, and 0% for groups 1-6, respectively, p < 0.0001). The optimal oxygen flow rate for HFNC determined by probit regression to effectively prevent desaturation in 95% of patients was 43.20 (95% confidence interval, 36.43-55.96) L/min. The requirement for airway intervention was significantly decreased by increasing the oxygen flow rate. CONCLUSION: An HFNC flow rate of 50-60 L/min is recommended to prevent desaturation during sedation for bronchoscopy. REGISTRATION: NCT05298319 at ClinicalTrials.gov.

High-flow nasal cannula oxygenation during bronchoscopyMany patients undergo a special test to check their airways for problems. Sometimes, doctors need to take out a small part of the area that's causing trouble to find out what's wrong. But during this test, some patients can struggle to get enough oxygen, which can even be life-threatening. To help with this, there's a device called a high-flow nasal cannula (HFNC). It gives patients adjustable amounts of oxygen, like a gentle breeze into their nose. But doctors weren't sure how much oxygen was best during this test. So, we studied 240 patients using HFNC at different oxygen levels­like slow, medium, and fast flows. We found that the higher the oxygen flow, the less likely patients were to have oxygen problems. For example, at the lowest flow (10 liters per minute), about 42.5% of patients had oxygen trouble, but at the highest flow (60 liters per minute), none did. And we figured out that a flow rate around 43.2 liters per minute would prevent 95% patients from having oxygen problems. So, we recommend using a flow rate between 50 and 60 liters per minute during this test to keep patients safe from oxygen issues.

Association between high-flow nasal cannula use and mortality in patients with sepsis-induced acute lung injury: a retrospective propensity score-matched cohort study.

BACKGROUND: High-flow nasal cannula (HFNC) has emerged as a promising noninvasive method for delivering oxygen to critically ill patients, particularly those with sepsis and acute lung injury. However, uncertainties persist regarding its therapeutic benefits in this specific patient population. METHODS: This retrospective study utilized a propensity score-matched cohort from the Medical Information Mart in Intensive Care-IV (MIMIC-IV) database to explore the correlation between HFNC utilization and mortality in patients with sepsis-induced acute lung injury. The primary outcome was 28-day all-cause mortality. RESULTS: In the propensity score-matched cohort, the 28-day all-cause mortality rate was 18.63% (95 out of 510) in the HFNC use group, compared to 31.18% (159 out of 510) in the non-HFNC group. The use of HFNC was associated with a lower 28-day all-cause mortality rate (hazard ratio [HR] = 0.53; 95% confidence interval [CI] = 0.41-0.69; P < 0.001). HFNC use was also associated with lower ICU mortality (odds ratio [OR] = 0.52; 95% CI = 0.38-0.71; P < 0.001) and lower in-hospital mortality (OR = 0.51; 95% CI = 0.38-0.68; P < 0.001). Additionally, HFNC use was found to be associated with a statistically significant increase in both the ICU and overall hospitalization length. CONCLUSIONS: These findings indicate that HFNC may be beneficial for reducing mortality rates among sepsis-induced acute lung injury patients; however, it is also associated with longer hospital stays.

Transition to Weight-Based High-Flow Nasal Cannula Use Outside of the ICU for Bronchiolitis.

Importance: Most children's hospitals have adopted weight-based high-flow nasal cannula (HFNC) bronchiolitis protocols for use outside of the intensive care unit (ICU) setting. Whether these protocols are achieving their goal of reducing bronchiolitis-related ICU admissions remains unknown. Objective: To measure the association between hospital transition to weight-based non-ICU HFNC use and subsequent ICU admission. Design, Setting, and Participants: This multicenter retrospective cohort study was conducted with a controlled interrupted time series approach and involved 18 children's hospitals that contribute data to the Pediatric Health Information Systems database. The cohort included patients aged 0 to 24 months who were hospitalized with a diagnosis of bronchiolitis between January 1, 2010, and December 31, 2021. Data were analyzed from July 2023 to January 2024. Exposure: Hospital-level transition from ICU-only to weight-based non-ICU protocol for HFNC use. Data for the ICU-only group were obtained from a previously published survey. Main Outcomes and Measures: Proportion of patients with bronchiolitis admitted to the ICU. Results: A total of 86 046 patients with bronchiolitis received care from 10 hospitals in the ICU-only group (n = 47 336; 27 850 males [58.8%]; mean [SD] age, 7.6 [6.2] years) and 8 hospitals in the weight-based protocol group (n = 38 710; 22 845 males [59.0%]; mean [SD] age, 7.7 [6.3] years). Mean age and sex were similar for patients between the 2 groups. Hospitals in the ICU-only group vs the weight-based protocol group had higher proportions of Black (26.2% vs 19.8%) and non-Hispanic (81.6% vs 63.8%) patients and patients with governmental insurance (68.1% vs 65.9%). Hospital transition to a weight-based HFNC protocol was associated with a 6.1% (95% CI, 8.7%-3.4%) decrease per year in ICU admission and a 1.5% (95% CI, 2.8%-0.1%) reduction per year in noninvasive positive pressure ventilation use compared with the ICU-only group. No differences in mean length of stay or the proportion of patients who received invasive mechanical ventilation were found between groups. Conclusions and Relevance: Results of this cohort study of hospitalized patients with bronchiolitis suggest that transition from ICU-only to weight-based non-ICU HFNC protocols is associated with reduced ICU admission rates.

The effects of flow settings during high-flow nasal cannula oxygen therapy for neonates and young children.

BACKGROUND: During neonatal and paediatric high-flow nasal cannula therapy, optimising the flow setting is crucial for favourable physiological and clinical outcomes. However, considerable variability exists in clinical practice regarding initial flows and subsequent adjustments for these patients. Our review aimed to summarise the impact of various flows during high-flow nasal cannula treatment in neonates and children. METHODS: Two investigators independently searched PubMed, Embase, Web of Science, Scopus and Cochrane for in vitro and in vivo studies published in English before 30 April 2023. Studies enrolling adults (≥18 years) or those using a single flow setting were excluded. Data extraction and risk of bias assessments were performed independently by two investigators. The study protocol was prospectively registered with PROSPERO (CRD42022345419). RESULTS: 38 406 studies were identified, with 44 included. In vitro studies explored flow settings' effects on airway pressures, humidity and carbon dioxide clearance; all were flow-dependent. Observational clinical studies consistently reported that higher flows led to increased pharyngeal pressure and potentially increased intrathoracic airway pressure (especially among neonates), improved oxygenation, and reduced respiratory rate and work of breathing up to a certain threshold. Three randomised controlled trials found no significant differences in treatment failure among different flow settings. Flow impacts exhibited significant heterogeneity among different patients. CONCLUSION: Individualising flow settings in neonates and young children requires consideration of the patient's peak inspiratory flow, respiratory rate, heart rate, tolerance, work of breathing and lung aeration for optimal care.

[Application of high flow nasal canula in patients with pulmonary edema caused by seawater drowning].

OBJECTIVE: To investigate the therapeutic effect of high-flow nasal cannula oxygen therapy (HFNC) and non-invasive positive pressure ventilation (NPPV) on patients with pulmonary edema caused by seawater drowning. METHODS: A retrospective analysis method was used. Based on the Utstein database of emergency drowning in the First Hospital of Qinhuangdao, the clinical data of patients with seawater drowning pulmonary edema admitted to the emergency medicine department of the First Hospital of Qinhuangdao from January 1, 2019 to December 31, 2022 were collected. The patients were divided into NPPV group and HFNC group according to different ventilation methods. The general data, endotracheal intubation rate in 7 days, arterial blood gas analysis indexes [arterial partial pressure of oxygen (PaO2), arterial partial pressure of carbon dioxide (PaCO2), arterial oxygen saturation (SaO2)] and hemodynamic indexes (systolic blood pressure, diastolic blood pressure, mean arterial pressure, heart rate, blood lactic acid) before and after treatment, length of stay in intensive care unit (ICU), oxygen therapy comfort of the two groups were compared. RESULTS: A total of 54 patients were enrolled, including 21 patients in the NPPV group and 33 patients in the HFNC group. There were no significant differences in gender, age, state of consciousness and other general information between the two groups. Compared with NPPV group, the rate of endotracheal intubation in HFNC group within 7 days was significantly lower [24.2% (8/33) vs. 33.3% (7/21), P < 0.05]. Before treatment, there were no significant differences in arterial blood gas analysis and hemodynamics between the two groups. After treatment, the above indexes in both groups were significantly improved compared with those before treatment, and PaO2, SaO2, systolic blood pressure, diastolic blood pressure and mean arterial pressure in HFNC group were significantly higher than those in NPPV group [PaO2 (mmHg, 1 mmHg≈0.133kPa): 93.56±6.37 vs. 82.14±6.25, SaO2: 1.02±0.09 vs. 0.95±0.11, systolic blood pressure (mmHg): 117.37±8.43 vs. 110.42±8.38, diastolic blood pressure (mmHg): 79.43±7.61 vs. 72.21±4.32, mean arterial pressure (mmHg): 92.34±6.32 vs. 85.12±5.38], PaCO2, heart rate and blood lactic acid were significantly lower than those in NPPV group [PaCO2 (mmHg) : 34.26±5.63 vs. 37.24±6.22, heart rate (times/min): 73.38±7.56 vs. 86.25±5.41, blood lactic acid (mmol/L): 1.38±0.36 vs. 2.25±1.14], and the differences were statistically significant (all P < 0.05). In addition, the length of ICU stay in HFNC group was significantly shorter than that in NPPV group (days: 13.30±2.38 vs. 16.27±4.26), and the comfort rate of oxygen therapy was significantly higher than that in NPPV group [66.7% (22/33) vs. 42.8% (9/21)], with statistical significance (all P < 0.05). CONCLUSIONS: HFNC can improve the oxygenation of patients with pulmonary edema caused by seawater drowning, improve hemodynamics, reduce the rate of tracheal intubation, shorten the length of ICU stay, and improve the comfort of oxygen therapy, which has certain clinical application value.

High-Flow and Low-Flow Oxygen Delivery by Nasal Cannula Evaluated in Infant and Adult Airway Replicas.

BACKGROUND: The nasal cannula is widely regarded as a safe and effective means of administering low- and high-flow oxygen to patients irrespective of their age. However, variability in delivered oxygen concentration (FDO2 FDO2 ) via nasal cannula has the potential to pose health risks. The present study aimed to evaluate predictive equations for FDO2 over a large parameter space, including variation in breathing, oxygen flow, and upper-airway geometry representative of both young children and adults. METHODS: Realistic nasal airway geometries were previously collected from medical scans of adults, infants, and neonates. Nasal airway replicas based on these geometries were used to measure the FDO2 for low-flow oxygen delivery during simulated spontaneous breathing. The present study extends previously published data sets to include higher oxygen flows. The extended data sets included nasal cannula oxygen flows that ranged from 6 to 65 L/min for the adult replicas, and from 0.5 to 6 L/min for the infant replicas. For both age groups, FDO2 was measured over a range of breathing frequencies, inspiratory to expiratory time ratios, and tidal volumes. Measured FDO2 values were compared with values predicted by using a previously derived flow-weighted equation. RESULTS: For both age groups, FDO2 was observed to increase nonlinearly with the ratio between oxygen flow supplied to the nasal cannula and the average inhalation flow. The previously derived flow-weighted equation over-predicted FDO2 at higher oxygen flows. A new empirical equation, therefore, was proposed to predict FDO2 for either age group as a function of nasal cannula flow, tidal volume, and inspiratory time. Predicted FDO2 values matched measured values, with average relative errors of 2.4% for infants and 4.3% for adults. CONCLUSIONS: A new predictive equation for FDO2 was obtained that accurately matched measured data in both adult and infant airway replicas for low- and high-flow regimens.

Axillary vein as an alternative venous access site for VV-ECMO cannulation: a case report.

BACKGROUND: Ultrasound-guided percutaneous axillary vein cannulation can reduce cannulation failure and mechanical complications, is as safe and effective as internal jugular vein cannulation, and is superior to subclavian vein cannulation using landmark technique. As far, reports of venovenous extracorporeal membrane oxygenation (VV-ECMO) with percutaneous axillary vein cannulation are rare. CASE PRESENTATION: A 64-year-old man presenting with dyspnea and chest tightness after aspirating sewage was admitted to the emergency department. Computed tomography (CT) showed diffuse exudation of both lungs and arterial blood gas analysis showed an oxygenation index of 86. He was diagnosed with aspiration pneumonia-induced acute respiratory distress syndrome (ARDS) and intubated for deteriorated oxygenation. Despite the combination therapy of protective mechanical ventilation and prone position, the patient's oxygenation deteriorated further, accompanied with multiple organ dysfunction syndrome, which indicated the requirement of support with VV-ECMO. However, vascular ultrasound detected multiple thrombus within bilateral internal jugular veins. As an alternative, right axillary vein was chosen as the access site of return cannula. Subsequently, femoral-axillary VV-ECMO was successfully implemented under the ultrasound guidance, and the patient's oxygenation was significantly improved. Unfortunately, the patient died of hyperkalemia-induced ventricular fibrillation after 36 h of VV-ECMO running. Despite the poor prognosis, the blood flow during ECMO run was stable, and we observed no bleeding complication, vascular injury, or venous return disorder. CONCLUSIONS: Axillary vein is a feasible alternative access site of return cannula for VV-ECMO if internal jugular vein access were unavailable.

Tailoring left ventricular assist device cannula implantation using coupled multi-scale multi-objective optimization.

BACKGROUND: The frequent occurrence of thromboembolic cerebral events continues to limit the widespread implementation of Ventricular Assist Devices (VAD) despite continued advancements in VAD design and anti-coagulation treatments. Recent studies point to the optimal positioning of the outflow graft (OG) as a potential mitigator of post implantation thromboembolism. OBJECTIVE: This study aims to examine the tailoring of the OG implantation orientation with the goal of minimizing the number of thrombi reaching the cerebral vessels by means of a formal shape optimization scheme incorporated into a multi-scale hemodynamics analysis. METHODS: A 3-D patient-specific computational fluid dynamics model is loosely coupled in a two-way manner to a 0-D lumped parameter model of the peripheral circulation. A Lagrangian particle-tracking scheme models and tracks thrombi as non-interacting solid spheres. The loose coupling between CFD and LPM is integrated into a geometric shape optimization scheme which aims to optimize an objective function that targets a drop in cerebral embolization, and an overall reduction in particle residence times. RESULTS: The results elucidate the importance of OG anastomosis orientation and placement particularly in the case that studied particle release from the OG, as a fivefold decrease in cerebral embolization was observed between the optimal and non-optimal implantations. Another case considered particle release from the ventricle and aortic root walls, in which optimal implantation was achieved with a shallow insertion angle. Particle release from all three origins was investigated in the third case, demonstrating that the optimal configurations were generally characterized by VAD flow directed along the central lumen of the aortic arch. Because optimal configurations depended on the anatomic origin of the thrombus, it is important to determine, in clinical studies, the most likely sites of thrombus formation in VAD patients.

In silico parametric analysis of femoro-jugular venovenous ECMO and return cannula dynamics: In silico analysis of femoro-jugular VV ECMO.

BACKGROUND: Increasingly, computational fluid dynamics (CFD) is helping explore the impact of variables like: cannula design/size/position/flow rate and patient physiology on venovenous (VV) extracorporeal membrane oxygenation (ECMO). Here we use a CFD model to determine what role cardiac output (CO) plays and to analyse return cannula dynamics. METHODS: Using a patient-averaged model of the right atrium and venae cava, we virtually inserted a 19Fr return cannula and a 25Fr drainage cannula. Running large eddy simulations, we assessed cardiac output at: 3.5-6.5 L/min and ECMO flow rate at: 2-6 L/min. We analysed recirculation fraction (Rf), time-averaged wall shear stress (TAWSS), pressure, velocity, and turbulent kinetic energy (TKE) and extracorporeal flow fraction (EFF = ECMO flow rate/CO). RESULTS: Increased ECMO flow rate and decreased CO (high EFF) led to increased Rf (R = 0.98, log fit). Negative pressures developed in the venae cavae at low CO and high ECMO flow (high CR). Mean return cannula TAWSS was >10 Pa for all ECMO flow rates, with majority of the flow exiting the tip (94.0-95.8 %). CONCLUSIONS: Our results underpin the strong impact of CO on VV ECMO. A simple metric like EFF, once supported by clinical data, might help predict Rf for a patient at a given ECMO flow rate. The return cannula imparts high shear stresses on the blood, largely a result of the internal diameter.

Association between the ROX index and mortality in patients with acute hypoxemic respiratory failure: a retrospective cohort study.

BACKGROUND: Although ROX index is frequently used to assess the efficacy of high-flow nasal cannula treatment in acute hypoxemic respiratory failure (AHRF) patients, the relationship between the ROX index and the mortality remains unclear. Therefore, a retrospective cohort study was conducted to evaluate the ability of the ROX index to predict mortality risk in patients with AHRF. METHOD: Patients diagnosed with AHRF were extracted from the MIMIC-IV database and divided into four groups based on the ROX index quartiles. The primary outcome was 28-day mortality, while in-hospital mortality and follow-up mortality were secondary outcomes. To investigate the association between ROX index and mortality in AHRF patients, restricted cubic spline curve and COX proportional risk regression were utilized. RESULT: A non-linear association (L-shaped) has been observed between the ROX index and mortality rate. When the ROX index is below 8.28, there is a notable decline in the 28-day mortality risk of patients as the ROX index increases (HR per SD, 0.858 [95%CI 0.794-0.928] P < 0.001). When the ROX index is above 8.28, no significant association was found between the ROX index and 28-day mortality. In contrast to the Q1 group, the mortality rates in the Q2, Q3, and Q4 groups had a substantial reduction (Q1 vs. Q2: HR, 0.749 [0.590-0.950] P = 0.017; Q3: HR, 0.711 [0.558-0.906] P = 0.006; Q4: HR, 0.641 [0.495-0.830] P < 0.001). CONCLUSION: The ROX index serves as a valuable predictor of mortality risk in adult patients with AHRF, and that a lower ROX index is substantially associated with an increase in mortality.

Utilization of immediate extubation in a multidisciplinary pathway for pediatric liver transplantation associated with improved postoperative outcomes.

BACKGROUND: Immediate extubation is becoming more common in liver transplantation. However, limited data exist on how to identify pediatric patients with potential for successful immediate extubation and how this intervention may affect recovery. METHODS: This retrospective review evaluated patients who underwent liver transplantation from 2015 to 2021 at Children's Healthcare of Atlanta. Preoperative status and intraoperative management were evaluated and compared. Outcomes comprised thrombosis, surgical reexploration, retransplantation, as well as reintubation, high flow nasal cannula (HFNC) usage, postoperative infection, the length of stay (LOS), and mortality. RESULTS: A total of 173 patients were analyzed, with 121 patients (69.9%) extubated immediately. The extubation group had older age (median 4.0 vs 1.25 years, p = .048), lower PELD/MELD (28 vs. 34, p = .03), decreased transfusion (10.2 vs. 41.7 mL/kg, p < .001), shorter surgical time (332 vs. 392 min, p < .001), and primary abdominal closure (81% vs. 40.4%, p < .001). Immediate extubation was associated with decreased HFNC (0.21 vs. 0.71 days, p = .02), postoperative infection (9.9% vs. 26.9%, p = .007), mortality (0% vs. 5.8%, p = .036), and pediatric intensive care unit LOS (4.7 vs. 11.4 days, p < .001). The complication rate was lower in the extubation group (24.8% vs. 36.5%), but not statistically significant. CONCLUSIONS: Approximately 70% of patients were able to be successfully extubated immediately, with only 2.5% requiring reintubation. Those immediately extubated had decreased need for HFNC, lower infection rates, shorter LOS, and decreased mortality. Our results show that with proper patient selection and a multidisciplinary approach, immediate extubation allows for improved recovery without increased respiratory complications after pediatric liver transplantation.

Hemodynamic Monitoring In The Cardiac Surgical Patient: Comparison of Three Arterial Catheters.

OBJECTIVE: Systemic systolic (SAP) and mean (MAP) arterial pressure monitoring is the cornerstone in hemodynamic management of the cardiac surgical patient, and the radial artery is the most common site of catheter placement. The present study compared 3 different arterial line procedures. It is hypothesized that a 20-G 12.7- cm catheter inserted into the radial artery will be equal to a 20-G 12.7- cm angiocath placed in the brachial artery, and superior to a 20-G 5.00 cm angiocath placed in the radial artery. DESIGN: A prospective randomized control study was performed. SETTING: Single academic university hospital. PARTICIPANTS: Adult patients ≥18 years old undergoing nonemergent cardiac surgery using cardiopulmonary bypass (CPB). INTERVENTIONS: After approval by the Rhode Island Hospital institutional review board, a randomized prospective control study to evaluate 3 different peripheral intraarterial catheter systems was performed: (1) Radial Short (RS): 20-G 5- cm catheter; (2) Radial Long (RL): 20-G 12- cm catheter; and (3) Brachial Long (BL): 20-G 12- cm catheter. MEASUREMENTS AND RESULTS: Gradients between central aortic and peripheral catheters (CA-P) were compared and analyzed before CPB and 2 and 10 minutes after separation from CPB. The placement of femoral arterial lines and administration of vasoactive medications were recorded. After exclusions, 67 BL, 61 RL, and 66 RS patients were compared. Before CPB, CA-P SAP and MAP gradients were not significant among the 3 groups. Two minutes after CPB, the CA-P SAP gradient was significant for the RS group (p = 0.005) and insignificant for BL (p = 0.47) and RL (p = 0.39). Two-group analysis revealed that CA-P SAP gradients are similar between BL and RL (p = 0.84), both of which were superior to RS (p = 0.02 and p = 0.04, respectively). At 10 minutes after CPB, the CA-P SAP gradient for RS remained significant (p = 0.004) and similar to the gradient at 2 minutes. The CA-P SAP gradients increased from 2 to 10 minutes for BL (p = 0.13) and RL (p = 0.06). Two minutes after CPB, the CA-P MAP gradients were significant for the BL (p = 0.003), RL (p < 0.0001), and RS (p < 0.0001) groups. Two-group analysis revealed that the CA-P MAP gradients were lower for the BL group compared with the RL (p = 0.054) and RS (p< 0.05) groups. Ten minutes after CPB, the CA-P MAP gradients in the RL and RS groups remained significant (p < 0.0001) and both greater than the BL group (p = 0.002). A femoral arterial line was placed more frequently in the RS group (8/66 = 12.1%) than in the RL group (3/61 = 4.9%) and the BL group (2/67 = 3.0%). Vasopressin was administered significantly more frequently in the RS group. CONCLUSION: Regarding CA-P SAP gradients, the RL group performed equally to the BL group, both being superior to RS. Regarding CA-P MAP gradients, BL was superior to RL and RS. Clinically, femoral line placement and vasopressin administration were fewer for the BL and RL groups when compared with the RS group. This study demonstrated the benefits of a long (12.7 cm) 20- G angiocath placed in the radial artery.

Risk factors for intubation and mortality in patients treated with high flow nasal cannula due to COVID-19 infection. Survival Analysis Study in a Northern Mexican Population.

BACKGROUND: COVID-19-related acute hypoxic respiratory failure patients often use high-flow nasal cannula (HFNO) oxygen therapy. COVID-19 HFNO intubation and mortality risk factors are understudied in the Mexican population, so the aim was to study them. METHODS: This retrospective study searched electronic medical records from March 2020 to June 2022 for patients with COVID-19 who required hospitalization and HFNO. Descriptive statistics, a survival curve analysis, and Cox proportional hazard models were used to determine predictor factors for intubation and mortality in patients with HFNO and COVID-19, respectively. RESULTS: A total of 134 patients received HFNO treatment. Ninety-one (67.9%) were men with a mean (SD) age of 54.5 (17.9) years. Common medical history included obesity (n = 89, 66.4%) with a Body Mass Index (BMI) mean (SD) of 31.8 (5.9), hypertension (n = 67, 50.0%), type 2 diabetes (n = 55, 41.0%), and dyslipidemias (n = 43, 32.1%). The variables associated with a greater risk of requiring intubation after high-flow therapy were age (HR = 1.018, 95% CI 1.003-1.034, p = 0.022) and BMI (HR = 1.071, 95% CI 1.024-1.120, p = 0.003). No variables were associated with lower risk. Increased mortality was associated with increasing age (HR = 1.151, 95% CI 1.102-1.201, p = <0.001), hypertension (HR = 4.092, 95% CI 1.369-12.236, p = 0.012), and dyslipidemia (HR = 3.954, 95% CI 1.395-11.209, p = 0.010). Patients with type 2 diabetes had a lower risk of mortality (HR = 0.235, 95% CI 0.080-0.688, p = 0.008). CONCLUSIONS: A higher age and BMI were associated with an increased risk of intubation in patients with HFNO and COVID-19. Hypertension and dyslipidemias were associated with a higher risk of mortality.