High-Flow Nasal Cannula and in-line aerosolised bronchodilator delivery during severe exacerbation of asthma in adults: A feasibility Observational Study.

BACKGROUND: Asthma is a common chronic respiratory disease affecting 1-29% of the population in different countries. Exacerbations represent a change in symptoms and lung function from the patient's usual condition that requires emergency department (ED) admission. Recently, the use of a High-Flow Nasal Cannula (HFNC) plus an in-line vibrating mesh nebulizer (VMN) for aerosol drug delivery has been advocated in clinical practice. Thus, this pilot observational study aims to investigate the feasibility of HFNC treatment with VMN for in-line bronchodilator delivery in patients with severe asthma. METHODS: This study was conducted from May 2022 to May 2023. Subjects ≥ 18 years old with a previous diagnosis of asthma who were admitted to the ED during severe exacerbation were included. The primary endpoint was the change in peak expiratory flow ratio (PEFR) after 2-h of treatment with bronchodilator delivered by HFNC with in-line VMN. Additional outcomes were changes in forced expiratory volume in 1 second (FEV1) and clinical variables before treatment. RESULTS: 30 patients mean age of 43 (SD ± 16) years, mostly female (67%) were studied. A significant change in PEFR (147 ± 31 L/m vs. 220 ± 38 L/m; p < 0.001) was observed after treatment with HFNC and in-line VMN with significant improvement in clinical variables. And no subjects required invasive mechanical ventilation (IMV) during the study. CONCLUSIONS: HFNC treatment with in-line VMN for bronchodilator delivery appears feasible and safe for patients with severe asthma exacerbation. These preliminary promising results should be confirmed with appropriately large-designed studies.

Factors associated with difficult intravenous access in the paediatric emergency department: A prospective cohort study.

OBJECTIVES: Although it is the most performed invasive procedure, peripheral intravenous catheter (PIVC) insertion in children can be difficult. The primary objective of the study was to identify the factors associated with difficult intravenous access (DIVA) in the paediatric ED, including patient, proceduralist and situational factors. METHODS: This was a single-centre prospective observational cohort study conducted over 28 consecutive days. Research assistants observed PIVC insertion attempts for children under 16 years of age and recorded data for variables relating to the patient, proceduralist and event. Univariate logistic regression modelling was performed to identify factors associated with DIVA, defined as unsuccessful PIVC insertion on the first attempt. RESULTS: A total of 134 participants were recruited; 66 were male (49%) with a median age of 5.7 years. Fifty-two (39%) were classified as having DIVA. There was a total of 207 PIVC insertion attempts with two or more attempts needed for 48 children (36%). Patient factors associated with DIVA included age of 3 years or less and limited vein options. Proceduralist factors included gestalt of 50% or less chance of success, use of a larger gauge (smaller bore) PIVC and less PIVC insertion experience. Situational factors included a combative child, higher pain score and loud ambient noise. CONCLUSIONS: The present study identified multiple patient, proceduralist and situational factors that were associated with DIVA in the paediatric ED. Future studies should explore the development and implementation of a package to address DIVA in children, with the patient-centred goals of reducing pain and improving success.

Comparison of two different Nasal Interfaces used in Non-Invasive Respiratory support in terms of Neonate comfort.

Background: Non-Invasive Ventilation (NIV) is the first choice approach in neonates with sufficient respiratory effort that require respiratory support. The type of nasal interface used in NIV affects both efficacy and patient comfort. The aim of this study is to investigate the effects of different nasal interfaces used in NIV support on neonatal patient comfort. Methods: Our study evaluated patients who received NIV support for 24 hours. The patients were randomly divided into two groups according to the type of nasal interface used, which were RAM cannula and short binasal prong (SBP). The patients' demographic and clinical data were noted. Their sleep was monitored for 24 hours with an actigraphy device. Results: A total of 82 patients were evaluated. The sleep efficiency in the RAM cannula group was significantly higher (respectively, 65.7% [10.22-95.25] vs. 57.81% [2.49-77], p=0.004). Although not statistically significant, the neonates in the RAM cannula group exhibited longer total sleep time (respectively, 10.4 ± 4.28 hours vs. 9.02 ± 3.73 hours, p=0.161). Comparison of heart rates and respiratory rates indicate that the patients in the RAM cannula group were more comfortable. Conclusions: Our study found that infants who received NIV support through a RAM cannula experienced more efficient sleep. Holistic approaches in neonatal intensive care units are vital for better neurodevelopmental outcomes in newborns. Although non-invasive, the interface used in NIV should also be a part of this holistic approach.

High Flow Nasal Cannula Versus Conventional Oxygen Therapy and Incidence of Post-Extubation Airway Obstruction in PICU: An Open-Label Randomized Controlled Trial (HiFloCOT-PICU Trial).

OBJECTIVES: To study the impact of high flow nasal cannula (HFNC) vs. conventional oxygen therapy (COT) (by simple nasal cannula) as respiratory support after extubation on the rates of post-extubation airway obstruction (PEAO) among mechanically ventilated critically ill children. METHODS: This open-label randomized controlled trial was conducted in pediatric intensive care unit (PICU) of a tertiary care teaching hospital in North India over a period of 7 mo (11 August 2021 to 10 March 2022). Children aged 3 mo to 12 y who required invasive mechanical ventilation for > 72 h and had passed spontaneous breathing trial (ready for extubation) were enrolled and randomized by computer generated block randomization to receive HFNC or COT after extubation. Primary outcome was rate of PEAO (assessed by modified Westley croup score, mWCS) within 48 h of extubation; and secondary outcomes were rate and number of adrenaline nebulization, treatment failure (requiring escalation of respiratory support), extubation failure, adverse events, and length of PICU stay in two groups. RESULTS: During the study period, 116 children were enrolled (58 each in HFNC and COT groups). There was no difference in rate of PEAO (55% vs. 51.7%, respectively), need of adrenaline nebulization, extubation failure, adverse events, and duration of PICU stay in two groups. However, the HFNC group had significantly lower rates of treatment failure (27.6% vs. 48.3%, p = 0.02). CONCLUSIONS: The rate of PEAO was similar in HFNC and COT groups. However, HFNC group had significantly lower rate of treatment failure requiring escalation of respiratory support.

Determining the optimum high-flow nasal cannula flow rate to achieve the desired fraction of inspired oxygen: A bench study.

BACKGROUND: Purpose: High-flow nasal cannula (HFNC) has many benefits in various clinical conditions. The original hypothesis suggests that the high and constant fraction of inspired oxygen (FiO2) is one of the main physiological effects. However, increasing evidence shows that there is a gap between the actual FiO2 and administered FiO2. We aimed to determine the actual FiO2 under different respiratory conditions and develop a regression model using a spontaneous breathing lung model. METHODS: A spontaneous breathing simulation model was built using an airway manikin and a model lung. The FiO2 was measured under different respiratory conditions with varying tidal volumes and respiratory and HFNC flow rates. The relationships between the respiratory parameters and actual FiO2 were determined and used to build the predictive model. RESULTS: The actual FiO2 was negatively correlated with respiratory rate and tidal volume and positively correlated with HFNC flow. The regression model could not be developed using simple respiratory parameters. Therefore, we introduced a new variable, defined as flow ratio, which equaled the HFNC flow divided by inspiratory flow. Our equation demonstrated that the actual FiO2 was mainly determined by the flow ratio in a non-linear relationship. Accordingly, a flow ratio greater than 1 did not ensure a constant high FiO2, whereas a flow ratio >1.435 could produce FiO2 >0.9. CONCLUSION: The FiO2 during HFNC was not constant even at sufficiently high oxygen flow compared with inspiratory flow. The predictive model showed that the actual FiO2 was mainly determined by the flow ratio.

Dos and don'ts to optimize transnasal aerosol drug delivery in clinical practice.

INTRODUCTION: Transnasal aerosol drug delivery has become widely accepted for treating acutely ill infants, children, and adults. More recently aerosol administration to wider populations receiving high and low-flow nasal oxygen has become common practice. AREAS COVERED: Skepticism of insufficient aerosol delivery to the lungs has been tempered by multiple in vitro explorations of variables to optimize delivery efficiency. Additionally, clinical studies demonstrated comparable clinical responses to orally inhaled aerosols. This paper provides essential clinical guidance on how to improve transnasal aerosol delivery based on device-, settings-, and drug-related optimization to serve as a resource for educational initiatives and quality enhancement endeavors at healthcare institutions. EXPERT OPINION: Transnasal aerosol delivery is proliferating worldwide, but indiscriminate use of excessive-high flows, poor selection and placement of aerosol devices and circuits can greatly reduce aerosol delivery and efficacy, potentially compromising treatment to acute and critically ill patients. Attention to these details can improve inhaled dose by an order of magnitude, making the difference between effective treatment and the progression to more invasive ventilatory support, with greater inherent risk and cost. These revelations have prompted specific recommendations for optimal delivery, driving advancements in aerosol generators, formulations, and future device designs to administer aerosols and maximize treatment effectiveness.

Hyperacute experimental model of rat lung transplantation using a coronary shunt cannula.

BACKGROUND: Lung transplantation is a well-established treatment of end-stage lung disease. A rodent model is an inexpensive way to collect biological data from a living model after lung transplantation. However, mastering the surgical technique takes time owing to the small organ size. AIM: To conduct rat lung transplantation using a shunt cannula (SC) or modified cannula (MC) and assess their efficacy. METHODS: Rat lung transplantation was performed in 11 animals in the SC group and 12 in the MC group. We devised a method of rat lung transplantation using a coronary SC for coronary artery bypass surgery as an anastomosis of pulmonary arteriovenous vessels and bronchioles. The same surgeon performed all surgical procedures in the donor and recipient rats without using a magnifying glass. The success rate of lung transplantation, operating time, and PaO2 values were compared after 2-h reperfusion after transplantation. RESULTS: Ten and 12 lungs were successfully transplanted in the SC and MC groups, respectively. In the SC group, one animal had cardiac arrest within 1 h after reperfusion owing to bleeding during pulmonary vein anastomosis. The operating time for the removal of the heart-lung block from the donor and preparation of the left lung graft was 26.8 ± 2.3 and 25.7 ± 1.3 min in the SC and MC groups, respectively (P = 0.21). The time required for left lung transplantation in the recipients was 37.5 ± 2.8 min and 35.9 ± 1.4 min in the SC and MC groups, respectively (P = 0.12). PaO2 values at 2 h after reperfusion were 456.2 ± 25.5 and 461.2 ± 21.5 mmHg in the SC and MC groups, respectively (P = 0.63), without difference between the groups. CONCLUSION: A hyperacute rat lung transplantation model using a coronary SC was created using a simple technique. The MC was inexpensive, easy to prepare, and simple to operate.

Analysis of Oxygen Concentration in the Oral Cavity During Intravenous Sedation with Intranasal Oxygen Administration for Dental Treatment.

Purpose: Intravenous sedation (IVS) with propofol (PPF) is commonly performed in dental treatment, particular in patients with dentophobia, with gag reflex, or undergoing implant surgeries, as PPF has the advantages of rapid induction and recovery. However, PPF and other intravenous sedatives may cause respiratory depression. Thus, IVS with PPF requires oxygen administration. But airway burn may occur when high-concentration oxygen is stored in the oral cavity and catches fire. For these reasons, the present study aimed to elucidate the changes in oxygen concentration (OC) under IVS with PPF and oxygen administration. Patients and methods: Nineteen healthy male volunteers participated in the study. None of them had missing teeth, nasal congestion, or temporomandibular joint dysfunction. They were sedated with a continuous PPF infusion dose of 6 mg/kg/hr for 25 min, followed by administration of 3 L/min oxygen via a nasal cannula. The OC was measured at two sites, namely, the median maxillary anterior teeth (MMAT) and median maxillary soft palate (MMSP), before PPF infusion (baseline) and 14, 15-18 (Term 1), 19, and 20-23 (Term 2) min after the start of infusion. Results: Compared with the values at baseline, the OC in the MMSP significantly increased at each time point, whereas the OC in the MMAT significantly increased at Term 2. Furthermore, in the comparison of the OC before and after the use of a mouth prop, the OC exhibited an upward trend, but no statistically significant differences were observed between the two time points in the MMAT and MMSP. In IVS with PPF and oxygen administration, the OC in the pharynx increases as the sedative level deepens. Conclusion: Oxygen administration should be temporarily discontinued, and suction should be performed to decrease the OC in the oral cavity when sparking procedures during IVS with PPF and oxygen administration are performed.

Racial Differences in Accuracy of Predictive Models for High-Flow Nasal Cannula Failure in COVID-19.

OBJECTIVES: To develop and validate machine learning (ML) models to predict high-flow nasal cannula (HFNC) failure in COVID-19, compare their performance to the respiratory rate-oxygenation (ROX) index, and evaluate model accuracy by self-reported race. DESIGN: Retrospective cohort study. SETTING: Four Emory University Hospitals in Atlanta, GA. PATIENTS: Adult patients hospitalized with COVID-19 between March 2020 and April 2022 who received HFNC therapy within 24 hours of ICU admission were included. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Four types of supervised ML models were developed for predicting HFNC failure (defined as intubation or death within 7 d of HFNC initiation), using routine clinical variables from the first 24 hours of ICU admission. Models were trained on the first 60% (n = 594) of admissions and validated on the latter 40% (n = 390) of admissions to simulate prospective implementation. Among 984 patients included, 317 patients (32.2%) developed HFNC failure. eXtreme Gradient Boosting (XGB) model had the highest area under the receiver-operator characteristic curve (AUROC) for predicting HFNC failure (0.707), and was the only model with significantly better performance than the ROX index (AUROC 0.616). XGB model had significantly worse performance in Black patients compared with White patients (AUROC 0.663 vs. 0.808, p = 0.02). Racial differences in the XGB model were reduced and no longer statistically significant when restricted to patients with nonmissing arterial blood gas data, and when XGB model was developed to predict mortality (rather than the composite outcome of failure, which could be influenced by biased clinical decisions for intubation). CONCLUSIONS: Our XGB model had better discrimination for predicting HFNC failure in COVID-19 than the ROX index, but had racial differences in accuracy of predictions. Further studies are needed to understand and mitigate potential sources of biases in clinical ML models and to improve their equitability.

Aerosol Delivery Efficiency With High-Flow Nasal Cannula Therapy in Neonatal, Pediatric, and Adult Nasal Upper-Airway and Lung Models.

BACKGROUND: High-flow nasal cannula (HFNC) systems employ different methods to provide aerosol to patients. This study compared delivery efficiency, particle size, and regional deposition of aerosolized bronchodilators during HFNC in neonatal, pediatric, and adult upper-airway and lung models between a proximal aerosol adapter and distal aerosol circuit chamber. METHODS: A filter was connected to the upper airway to a spontaneously breathing lung model. Albuterol was nebulized using the aerosol adapter and circuit at different clinical flow settings. The aerosol mass deposited in the upper airway and lung was quantified. Particle size was measured with a laser diffractometer. Regional deposition was assessed with a gamma camera at each nebulizer location and patient model with minimum flow settings. RESULTS: Inhaled lung doses ranged from 0.2-0.8% for neonates, 0.2-2.2% for the small child, and 0.5-5.2% for the adult models. Neonatal inhaled lung doses were not different between the aerosol circuit and adapter, but the aerosol circuit showed marginally greater lung doses in the pediatric and adult patient models. Impacted aerosols and condensation in the non-heated HFNC and aerosol delivery components contributed to the dispersion of coarse liquid droplets, high deposition (11-44%), and occlusion of the supine neonatal upper airway. In contrast, the upright pediatric and adult upper-airway models had minimal deposition (0.3-7.0%) and high fugitive losses (∼24%) from liquid droplets leaking out of the nose. The high impactive losses in the aerosol adapter (56%) were better contained than in the aerosol circuit, resulting in less cannula sputter (5% vs 22%), fewer fugitive losses (18% vs 24%), and smaller inhaled aerosols (5 µm vs 13 µm). CONCLUSIONS: The inhaled lung dose was low (1-5%) during HFNC. Approaches that streamline aerosol delivery are needed to provide safe and effective therapy to patients receiving aerosolized medications with this HFNC system.

Effectiveness of High-Flow Nasal Cannula (RAM Cannula) With T-piece Resuscitator to Deliver Continuous Positive Airway Pressure (CPAP) During Neonatal Transport.

Background Newborns frequently experience respiratory distress (RD), necessitating preventive management during transportation. The use of Continuous Positive Airway Pressure (CPAP) is crucial in mitigating RD in neonates, particularly during transit. This study aims to assess the feasibility and efficacy of utilizing a RAM cannula (Neotech Products, Valencia, USA) with a T-piece resuscitator to deliver CPAP during neonatal transport. The objective is to evaluate the response of transported neonates to this intervention, including improvements in distress, surfactant requirements, ventilator dependency, and complications. Method and material Neonates with RD qualifying for CPAP support at birth and requiring transport to Neonatal Intensive Care Unit (NICU) care were included. The average duration of transport was 38 minutes (range 12 minutes to 2 hours). RAM cannula with a T-piece resuscitator was used for CPAP delivery during transportation. Vital parameters and interventions were monitored during transit, and outcomes were compared with inborn neonates receiving standard CPAP in the labor room. Results Out of 48 babies, nine babies required surfactant, and four needed invasive ventilation, with three developing a nasal injury. Compared to in-house preterm babies, these babies had more Positive End Expiratory Pressure (PEEP) knob adjustment, desaturation episodes, late surfactant administration, and intubation needs. Conclusion A high-flow nasal cannula combined with a T-piece resuscitator emerges as a promising modality for CPAP delivery during neonatal transportation, demonstrating efficacy with minimal complications.

Dual-Lumen Extracorporeal Membrane Oxygenation Cannulation Technique Using Only Transthoracic Echocardiography - A Case Series.

BACKGROUND: Bicaval dual lumen cannula (DLC) is gaining popularity in veno-venous extracorporeal membrane oxygenation (V-V ECMO) for having less recirculation and facilitating mobilization. It is usually inserted under fluoroscopic or transesophageal echocardiographic guidance to prevent potentially fatal complications. Thus, their utilization was limited during the COVID-19 outbreak due to stringent quarantine policy and manpower shortage, especially when emergency insertion was required. PURPOSE: To describe our experience on DLC insertion using transthoracic echocardiography alone during the pandemic, with a focus on safety considerations by using detail step-by-step procedural guide. OUTCOME: Four patients were performed V-V ECMO using the transthoracic echocardiographic-guided DLC cannulation technique during the fifth wave of the COVID-19 outbreak, with no cannulation-related complications. CONCLUSION: Transthoracic echocardiographic guidance for DLC insertion is feasible and probably safe with a detailed guide, which can be adopted as a supplementary tool during future endemic outbreaks.

Feasibility of synchronized high flow nasal cannula.

BACKGROUND: A high-flow nasal cannula (cHFNC) delivers flow continuously (during inspiration and expiration). Using the diaphragm electrical activity (Edi), synchronizing HFNC could be an alternative (cycling high/low flow on inspiration/expiration, respectively). The objective of this study was to demonstrate the feasibility of synchronized HFNC (sHFNC) and compare it to cHFNC. METHODS: Different levels of cHFNC and sHFNC (4, 6, 8, and 10 liters per minute [LPM], with 2 LPM on expiration for sHFNC) were compared in eight rabbits (mean weight 3.16 kg), before and after acute lung injury (pre-ALI and post-ALI). Edi, tracheal pressure (Ptr), esophageal pressure (Pes), flow, and arterial CO2 were measured. In addition to the animal study, one 3.52 kg infant received sHFNC and cHFNC using a Servo-U ventilator. RESULTS: In the animal study, there were more pronounced decreases in Edi, reduced Pes swings and reduced PaCO2 at comparable flows during sHFNC compared to cHFNC both pre and post-ALI (p < .05). Baseline (pre-inspiratory) Ptr was 2-7 cmH2O greater during cHFNC (p < .05) indicating more dynamic hyperinflation. In one infant, the ventilator performed as expected, delivering Edi-synchronized high/low flow. CONCLUSION: Synchronizing high flow unloaded breathing, decreased Edi, and reduced PaCO2 in an animal model and is feasible in infants.

High flow nasal cannula oxygen therapy versus non-invasive ventilation for acute exacerbations of chronic obstructive pulmonary disease with acute-moderate hypercapnic respiratory failure: a randomized controlled non-inferiority trial.

BACKGROUND: Although cumulative studies have demonstrated a beneficial effect of high-flow nasal cannula oxygen (HFNC) in acute hypercapnic respiratory failure, randomized trials to compare HFNC with non-invasive ventilation (NIV) as initial treatment in acute exacerbations of chronic obstructive pulmonary disease (AECOPD) patients with acute-moderate hypercapnic respiratory failure are limited. The aim of this randomized, open label, non-inferiority trial was to compare treatment failure rates between HFNC and NIV in such patients. METHODS: Patients diagnosed with AECOPD with a baseline arterial blood gas pH between 7.25 and 7.35 and PaCO2 ≥ 50 mmHg admitted to two intensive care units (ICUs) at a large tertiary academic teaching hospital between March 2018 and December 2022 were randomly assigned to HFNC or NIV. The primary endpoint was the rate of treatment failure, defined as endotracheal intubation or a switch to the other study treatment modality. Secondary endpoints were rates of intubation or treatment change, blood gas values, vital signs at one, 12, and 48 h, 28-day mortality, as well as ICU and hospital lengths of stay. RESULTS: 225 total patients (113 in the HFNC group and 112 in the NIV group) were included in the intention-to-treat analysis. The failure rate of the HFNC group was 25.7%, while the NIV group was 14.3%. The failure rate risk difference between the two groups was 11.38% (95% CI 0.25-21.20, P = 0.033), which was higher than the non-inferiority cut-off of 9%. In the per-protocol analysis, treatment failure occurred in 28 of 110 patients (25.5%) in the HFNC group and 15 of 109 patients (13.8%) in the NIV group (risk difference, 11.69%; 95% CI 0.48-22.60). The intubation rate in the HFNC group was higher than in the NIV group (14.2% vs 5.4%, P = 0.026). The treatment switch rate, ICU and hospital length of stay or 28-day mortality in the HFNC group were not statistically different from the NIV group (all P > 0.05). CONCLUSION: HFNC was not shown to be non-inferior to NIV and resulted in a higher incidence of treatment failure than NIV when used as the initial respiratory support for AECOPD patients with acute-moderate hypercapnic respiratory failure. TRIAL REGISTRATION: chictr.org (ChiCTR1800014553). Registered 21 January 2018, http://www.chictr.org.cn.

Ultrasound-Guided Versus Palpation-Guided Techniques to Achieve Vascular Access in Children Undergoing Cardiac Surgery: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

Pediatric heart surgery is a vital therapeutic option for congenital heart disease, which is one of the most prevalent causes of death in children. Arterial cannulation (AC) and central venous catheter (CVC) are required in pediatric cardiac surgery for continuous monitoring of the central venous pressure (CVP), replacement of fluid or blood products, close hemodynamic monitoring, and frequent sampling for arterial blood gases (ABG). A systematic review and meta-analysis synthesizing evidence from randomized controlled trials (RCTs) retrieved from PubMed, Embase Cochrane, Scopus, and WOS until February 2024. Risk ratio (RR) was used to report dichotomous outcomes, and mean difference (MD) was used to report continuous outcomes, both with a 95% confidence interval (CI) using the random-effects model. Thirteen RCTs with 1060 children were included. Regarding arterial cannulation, the ultrasound-guided technique (US) was associated with a statistically significant increase in successful cannulation [RR: 1.31 with 95% CI (1.10, 1.56), P < 0.0001], and first-attempt success [RR: 1.88 with 95% CI (1.35, 2.63), P < 0.0001]. However, US was not associated with any statistically significant difference in venous cannulation in both outcomes with [RR: 1.13 with 95% CI (0.98, 1.30), P = 0.10], [RR: 1.53 with 95% CI (0.86, 2.71), P = 0.15] respectively. Moreover, US was associated with a statistically significant decrease in the number of attempts either in arterial cannulation with [MD: - 0.73 with 95% CI (- 1.00, - 0.46), P < 0.0001] or in venous cannulation with [MD: - 1.34 with 95% CI (- 2.55, - 0.12), P = 0.03], and the time of attempted cannulation also either in arterial cannulation with [MD: - 2.27 with 95% CI (- 3.38, - 1.16), P < 0.0001] or in venous cannulation with [MD: - 4.13 with 95% CI (- 7.06, - 1.19), P < 0.0001]. US guidance improves successful cannulation rates and first-attempt success in arterial access and reduces the number of attempts and procedural time for arterial and venous access. It was also associated with a lower incidence of complications and procedure failure, particularly in arterial access. However, it was associated with a higher incidence of venous puncture.

CARING: Cannula for Alleviation of Retinal Injury Caused by Needle Fluidic Gashing.

Infusion-related iatrogenic retinal breaks (IRBs) are a significant complication in vitrectomies, particularly when smaller-gauge cannulas are used during fluid infusion. Using two-dimensional finite element analysis (FEA), we analyzed forces exerted on the retina from different cannulas: traditional 25-gauge, 20-gauge, 23-gauge, and 27-gauge, then investigated four alternative new cannula designs: (A) oblique orifices, (B) external obstruction, (C) side ports, and (D) perpendicular orifices. The analysis revealed that the standard 25-gauge cannula had a force of 0.546 milli-Newtons (mN). Optimized cannulas demonstrated decreased forces: 0.072 mN (A), 0.266 mN (B), 0.417 mN (C), and 0.117 mN (D). While all the designs decrease fluid jet force, each has unique challenges: Design A may complicate manufacturing, B requires unique attachment techniques, C could misdirect fluid toward the lens and peripheral retina, and D requires a sealed trocar/cannula design to prevent unwanted fluid ejection. These four innovative cannula designs, identified with detailed engineering simulations, provide promising strategies to reduce the risk of IRBs during vitrectomy, bridging the gap between engineering insights and clinical application.

Nutrition therapy in non-intubated patients with acute respiratory failure: a narrative review.

Objectives: Non-invasive ventilation use is increasing in patients from acute respiratory failure. However, nutritional assessment and medical nutritional therapy are often missed and patients may be frequently underfed. This review evaluates the tools for nutritional screening and assessment, assesses the use of medical nutritional therapy in various techniques of non invasive ventilation and suggested tools to improve this therapy. Methods, results: A review of the literature was performed to evaluate the tools available to define malnutrition and determine the energy needs of patients requiring non invasive ventilation. Energy and protein intake was assessed in 16 recent papers. High Flow Nasal Cannula Oxygen therapy and non invasive ventilation using mask were described and nutritional therapy determined in each condition.The Global Leadership International Malnutrition Assessment seems to be the best assessment to be recommended. Energy expenditure is optimally obtained by indirect calorimetry. Patients with Non invasive ventilation are even more underfed than patients receiving High Flow Nasal Cannula Oxygen therapy. Conclusions: A better determination of malnutrition, a more adequate energy requirement and an improved energy and protein administration are required in patients with acute respiratory failure treated with non invasive ventilation.

High-flow nasal cannula oxygen therapy in seven cats with respiratory failure.

CASE SERIES SUMMARY: This case series describes seven cats that were treated with high-flow nasal cannula oxygen therapy (HFNOT). Seven cats were prospectively (n = 5) or retrospectively (n = 2) included from three veterinary university referral centers between March 2020 and September 2023. Data on signalment, medical history, clinical and diagnostic findings, treatment administered, response to HFNOT and outcomes were recorded. All cats included in this case series failed to respond to oxygen cage or flow-by oxygen therapy and were subsequently transitioned to HFNOT. After this transition, these cats demonstrated a marked improvement in respiratory parameters, including respiratory rate, effort and oxygen saturation measured by pulse oximetry, within 1 h of initiating HFNOT. All cats tolerated HFNOT well without any complications. RELEVANCE AND NOVEL INFORMATION: There is limited literature reporting the use of HFNOT in feline patients. This is the first case series in the literature of HFNOT utilized as an advanced oxygen delivery method for feline respiratory failure. This case series indicates that HFNOT improves oxygenation in feline patients that fail to respond to conventional oxygen therapy.

Seven cats with respiratory failure received high-flow nasal cannula oxygen therapy, which improved their oxygenation. Three were successfully weaned off the therapy, and one survived and was discharged.

[High-flow nasal oxygen versus conventional oxygen therapy during cesarean section under neuraxial anesthesia in pregnant women with heart disease: a randomized controlled trial].

OBJECTIVE: To evaluate the beneficial effects of high-flow nasal cannula (HFNC) oxygen therapy during cesarean section in pregnant women with heart disease. METHODS: We conducted a single-center, single-blinded randomized trial of HFNC oxygen therapy in pregnant women with heart disease undergoing cesarean section under neuraxial anesthesia.The participants were randomly assigned to receive either HFNC oxygen therapy with inspiratory flow of 30 L/min with 40% FIO2(n=27) or conventional oxygen therapy (COT) with oxygen flow rate of 5 L/min via a nasal cannula (n=31).The primary outcome was maternal desaturation (SpO2 < 94% lasting more than 3 min or PaO2/FIO2≤300 mmHg). RESULTS: Maternal desaturation was observed in 7.4%(2/27) of the women in HFNC group and in 32.3%(10/31) in the COT group.None of the cases required tracheal intubation during the perioperative period.The HFNC group had a significantly higher incidence of postoperative leukocytosis (P < 0.05) but without pyrexia or other inflammation-related symptoms.There were no significant differences between the two groups in the secondary maternal outcomes (need for respiratory support, maternal ICU admission, postoperative respiratory complications, and cardiovascular complications) or neonatal outcomes (P>0.05). CONCLUSION: In pregnant women with heart disease, HFNC therapy can significantly reduce the rate of maternal desaturation during the perioperative period of cesarean section without adverse effects on short-term maternal or fetal outcomes.

Impact of high-flow oxygen therapy via high velocity nasal insufflation on diaphragmatic thickening fraction in healthy subjects.

OBJECTIVE: The primary objective of this study was to evaluate the impact of high-flow nasal cannula oxygen therapy [HFNC] on the diaphragm thickening fraction. DESIGN: Prospective, descriptive, cohort study SETTING: The study was conducted in the Physiology and Respiratory Care Laboratory, Intensive Care Unit, Hospital Británico de Buenos Aires. PARTICIPANTS: Thirteen healthy subjects >18 years old INTERVENTIONS: High-flow nasal cannula oxygen therapy MAIN VARIABLES OF INTEREST: Demographic data (age and gender), anthropometric data (weight, height, and body mass index), and clinical and respiratory variables (Diaphragm thickening fraction [DTf], esophageal pressure swing, respiratory rate [RR], esophageal pressure-time product per minute [PTPes/min]). RESULTS: Median DTf decreased significantly as flow increased (p < 0.05). The baseline DTf measurement was 21.4 %, 18.3 % with 20 L/m, and 16.4 % with 40 L/m. We also observed a significant decrease in RR as flow increased in HFNC (p < 0.05). In the 8 subjects with recordings, the PTPes/min was 81.3 (±30.8) cmH2O/sec/min and 64.4 (±25.3) cmH2O/sec/min at baseline and 40 L/m respectively (p = 0.044). CONCLUSIONS: The use of high-flow oxygen therapy through nasal cannula of HFNC in healthy subjects decreases the DTf and RR in association with increased flow. In addition, the use of 40 L/m flow may reduce the muscular work associated with respiration.