scholarly journals HIGH FLOW NASAL OXYGEN- ALL YOU SHOULD KNOW

2021 ◽  
pp. 15-17
Author(s):  
Sumer Sanjiv Choudhary ◽  
Aakansha Sarda ◽  
B. O. Tayade
Keyword(s):  
Flow Rate ◽  
Maximum Flow ◽  
High Flow ◽  
Maximum Flow Rate ◽  
First Line ◽  
Hypoxemic Respiratory Failure ◽  
Fraction Of Inspired Oxygen ◽  
Support Devices ◽  
Inspired Oxygen ◽  
Adequate Oxygenation

Respiratory support is applied to maintain adequate oxygenation and ventilation and hence supplemental oxygenation is the first line of treatment for hypoxemic respiratory failure. There are multiple conventional oxygen support devices. However, in majority of these, oxygen provided is not humidified and maximum flow rate is 15l/min. However, high flow nasal oxygen (HFNO) is an alternative to conventional oxygen therapy. It is a technique that delivers heated and humidified oxygen with a controlled fraction of inspired oxygen(FiO2) at a maximum flow rate of 60L/min via (1) a specialized nasal cannula

scholarly journals SpO2/FiO2 as a predictor of high flow nasal cannula outcomes in children with acute hypoxemic respiratory failure

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ga Eun Kim ◽  
Sun Ha Choi ◽  
Mireu Park ◽  
Jae Hwa Jung ◽  
Myeongjee Lee ◽  
...  
Keyword(s):  
Respiratory Failure ◽  
Predictive Factors ◽  
High Flow ◽  
Nasal Cannula ◽  
High Flow Nasal Cannula ◽  
Hypoxemic Respiratory Failure ◽  
Acute Hypoxemic Respiratory Failure ◽  
Fraction Of Inspired Oxygen ◽  
Oxygen Ratio ◽  
Inspired Oxygen

AbstractThe high-flow nasal cannula (HFNC) is a useful treatment modality for acute hypoxemic respiratory failure (AHRF) in children. We compared the ability of the oxygen saturation to fraction of inspired oxygen ratio (S/F) and arterial oxygen partial pressure to fraction of inspired oxygen ratio (P/F) to predict HFNC outcomes in children with AHRF. This study included children treated with HFNC due to AHRF from April 2013 to March 2019 at the Severance Children’s Hospital. HFNC failure was defined as the need for mechanical ventilation. Trends of S/F and P/F during HFNC were analyzed. To predict HFNC outcomes, a nomogram was constructed based on predictive factors. A total of 139 patients with arterial blood gas data were included in the S/F and P/F analyses. S/F < 230 at initiation showed high prediction accuracy for HFNC failure (area under the receiver operating characteristic curve: 0.751). Univariate analyses identified S/F < 230 at HFNC initiation and < 200 at 2 h (odds ratio [OR] 12.83, 95% CI 5.06–35.84), and hemato-oncologic disease (OR 3.79, 95% CI 1.12–12.78) as significant predictive factors of HFNC failure. The constructed nomogram had a highly predictive performance, with a concordance index of 0.765 and 0.831 for the exploratory and validation groups, respectively. S/F may be used as a predictor of HFNC outcomes. Our nomogram with S/F for HFNC failure within 2 h may prevent delayed intubation in children with AHRF.

scholarly journals SPO2/FiO2 as a predictor of high-flow nasal cannula outcomes in children with acute hypoxemic respiratory failure: A retrospective study

2021 ◽  
Author(s):  
Ga Eun Kim ◽  
Sun Ha Choi ◽  
Mi Reu Park ◽  
Jae Hwa Jung ◽  
Myeongjee Lee ◽  
...  
Keyword(s):  
Respiratory Failure ◽  
Respiratory Distress ◽  
Odds Ratio ◽  
High Flow ◽  
High Flow Nasal Cannula ◽  
Hypoxemic Respiratory Failure ◽  
Acute Hypoxemic Respiratory Failure ◽  
Fraction Of Inspired Oxygen ◽  
Oxygen Ratio ◽  
Inspired Oxygen

Abstract Background: High-flow nasal cannula (HFNC) is a useful treatment modality for respiratory distress in children, as it provides effective oxygenation and reduces the work required for breathing. This study aimed to determine whether the oxygen saturation to fraction of inspired oxygen ratio (S/F) is a better predictor of HFNC outcomes than the arterial oxygen partial pressure to fraction of inspired oxygen ratio (P/F) in children with acute hypoxemic respiratory failure (AHRF).Methods: This study included children treated with HFNC for AHRF between April 2013 and March 2019 at the Severance Children’s Hospital in Korea. HFNC failure was defined as the need for mechanical ventilation due to worsening respiratory distress, whereas HFNC success was defined as the improvement of respiratory distress. We analyzed trends in S/F and P/F during HFNC oxygen therapy. A nomogram was constructed based on predictive factors identified via univariate analysis, and was externally validated using independent data.Results: A total of 139 patients with arterial blood gas data were included in the S/F and P/F analysis. There was a good correlation between S/F and P/F (P<0.001). The S/F at HFNC initiation was <230 and showed a high prediction accuracy for HFNC failure (area under the receiver operating characteristic curve: 0.751). Univariate analyses identified S/F <230 at HFNC initiation, S/F <200 at 2 h (odds ratio, 12.83; 95% confidence interval, 5.06-35.84), and hemato-oncologic disease (odds ratio, 3.79; 95% confidence interval, 1.12-12.78) as significant predictive factors for HFNC failure. These factors were used to construct a nomogram, which was shown to be highly predictive of HFNC outcomes; the concordance index of the exploratory and validation groups were 0.765 and 0.831, respectively.Conclusions: S/F may be used as a predictor of HFNC outcomes. Our nomogram with S/F for HFNC failure within 2 h may be used to prevent delayed intubation in children with AHRF.

Lichen sclerosis–induced long segment anterior urethral stricture: The early outcome of one-stage repair using dorsolateral onlay buccal mucosa graft

2021 ◽  
pp. 039156032110033
Author(s):  
Atef Fathi ◽  
Omar Mohamed ◽  
Osama Mahmoud ◽  
Gamal A Alsagheer ◽  
Ahmed M Reyad ◽  
...  
Keyword(s):  
Success Rate ◽  
Urethral Stricture ◽  
Flow Rate ◽  
Urine Volume ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
P Value ◽  
Onlay Graft ◽  
Voiding Symptoms ◽  
Stricture Recurrence

Background: Substitution urethroplasty using buccal mucosal grafts can be performed by several approaches including ventral onlay graft, dorsal onlay graft, or ventral urethrotomy with dorsal inlay graft. Our study aims to evaluate the surgical outcome of dorsolateral buccal mucosal graft for long segment anterior urethral stricture >6 cm in patients with Lichen sclerosus (LS). Methods: A retrospective study included patients who underwent repair for long segment anterior urethral stricture >6 cm due to LS between January 2013 and April 2019. All patients were followed-up at 3, 6, 9, and 12 months postoperatively and then yearly by clinical symptoms, uroflowmetry, and calculation of post-void residual urine volume. Retrograde urethrogram was requested for patients with voiding symptoms or decreased maximum flow rate. Stricture recurrence that required subsequent urethrotomy or urethroplasty was considered failure. The success rate and surgical complications were collected and analyzed. Results: Thirty patients were identified. The median age (range) was 39 (25–61) years and a median (range) stricture length was 8 (6–14) cm. Most of postoperative complications were of minor degree. The success rate at median follow-up of 15 (12–24) months was 86.5%. The median maximum flow rate increased significantly from 6 (2–11) ml/s preoperatively to 18 (range: 6–23) ml/s at the 6th month ( p value < 0.001). Conclusion: Dorsolateral buccal mucosal grafts urethroplasty for long anterior urethral stricture caused by LS has a high success rate and low risk of complications including stricture recurrence.

scholarly journals Maximum Flow Rate of a Single Component, Two-Phase Mixture

1965 ◽  
Vol 87 (1) ◽  
pp. 134-141 ◽  
Author(s):  
F. J. Moody
Keyword(s):  
Flow Rate ◽  
Static Pressure ◽  
Maximum Flow ◽  
Single Component ◽  
Maximum Flow Rate ◽  
Vapor Flow ◽  
Two Phase ◽  
Slip Ratio ◽  
Phase Mixture ◽  
Local Slip

A theoretical model is developed for predicting the maximum flow rate of a single component, two-phase mixture. It is based upon annular flow, uniform linear velocities of each phase, and equilibrium between liquid and vapor. Flow rate is maximized with respect to local slip ratio and static pressure for known stagnation conditions. Graphs are presented giving maximum steam/water flow rates for: local static pressures between 25 and 3,000 psia, with local qualities from 0.01 to 1.00; local stagnation pressures and enthalpies which cover the range of saturation states.

Effect of Blade Angle of Attack and Hub to Tip Ratio on Mass Flow Rate in an Axial Fan at a Fixed Rotational Speed

2008 ◽  
Author(s):  
Mohammad J. Izadi ◽  
Alireza Falahat
Keyword(s):  
Mass Flow Rate ◽  
Mass Flow ◽  
Flow Rate ◽  
Rotational Speed ◽  
Angle Of Attack ◽  
Maximum Flow ◽  
Maximum Flow Rate ◽  
Maximum Mass ◽  
Blade Angle ◽  
Axial Fan

In this investigation an attempt is made to find the best hub to tip ratio, the maximum number of blades, and the best angle of attack of an axial fan with flat blades at a fixed rotational speed for a maximum mass flow rate in a steady and turbulent conditions. In this study the blade angles are varied from 30 to 70 degrees, the hub to tip ratio is varied from 0.2 to 0.4 and the number of blades are varied from 2 to 6 at a fixed hub rotational speed. The results show that, the maximum flow rate is achieved at a blade angle of attack of about 45 degrees for when the number of blades is set equal to 4 at most rotational velocities. The numerical results show that as the hub to tip ratio is decreased, the mass flow rate is increased. For a hub to tip ratio of 0.2, and an angle of attack around 45 degrees with 4 blades, a maximum mass flow rate is achieved.

The characters exploration of a piezoelectric pump with fishtail-shaped bluffbody

2021 ◽  
pp. 1045389X2110386
Author(s):  
Yi Hou ◽  
Lipeng He ◽  
Zheng Zhang ◽  
Baojun Yu ◽  
Hong Jiang ◽  
...  
Keyword(s):  
Flow Rate ◽  
Preliminary Investigation ◽  
Maximum Flow ◽  
Theoretical Explanation ◽  
Maximum Flow Rate ◽  
Bluff Bodies ◽  
Conical Flow ◽  
Piezoelectric Pump ◽  
Valveless Piezoelectric Pump ◽  
Shape And Size

This paper focuses on a new structure in the valveless piezoelectric pump, which has a combination structure of the conical flow channel and two fishtail-shaped bluffbodies in the chamber of the pump. The fishtail-shaped bluffbody is inspired by the shape of the swimming fish to diminish the backflow and optimize the performance of the pump. The performance is studied by changing the shape and size of the inlet and outlet, the bluff bodies’ height and the space between two bluff bodies. The results show that the 3 mm × 3 mm square inlet, 3 mm diameter round outlet, 3 mm height of bluffbodies, 6.8 mm pitch of bluffbodies has a best performance in all 10 prototypes, which implements a maximum flow rate of 87.5 ml/min at 170 V 40 Hz with a noise of 42.6 dB. This study makes a preliminary investigation and theoretical explanation for the subsequent optimization of this structure, improved the performance of the valveless piezoelectric pump, broaden the thinking of the design for the bluffbody for better performance of the valveless piezoelectric pump.

Transport of Particle-Laden Fluids Through Fixed-Valve Micropumps

1999 ◽  
Author(s):  
Ling-Sheng Jang ◽  
Christopher J. Morris ◽  
Nigel R. Sharma ◽  
Ron L. Bardell ◽  
Fred K. Forster
Keyword(s):  
Surface Charge ◽  
Surface Area ◽  
Flow Rate ◽  
Pure Water ◽  
Maximum Flow ◽  
Total Surface Area ◽  
Maximum Flow Rate ◽  
Number Density ◽  
Polystyrene Microspheres ◽  
Negative Surface

Abstract Micropumps designed for the flow-rate range of 100–1000μl/min have been developed by a number of research groups. However, little data is available regarding the ability of various designs to directly transport liquids containing particles such as cells, microspheres utilized for bead chemistry, or contaminants. In this study the ability of pumps with no-moving-parts valves (NMPV) to transport particles was investigated. The results showed that a NMPV micropump was able to directly pump suspensions of polystyrene microspheres from 3.1 to 20.3μm in diameter. The pump functioned without clogging at microsphere number densities as high as 9000 particles/μl of suspension, which corresponded to over 90,000 particles per second passing through the pump at a flow rate of 600μl/min. Performance with polystyrene microspheres was the same as pure water up to the point of cavitation. Microspheres manufactured with negative surface charge cavitated less readily that other microspheres studied that were manufactured without surface charge. However, cavitation did not appear to be a function of microsphere size, total surface area or number density. Thus pumping polystyrene microspheres was found to be more affected by surface effects than by size, surface area or number density within the range of parameters considered. In the case of charged microspheres, the maximum flow rate was reduced by 30% compared to pure water whereas for uncharged microspheres the maximum flow rate was reduced by approximately 80%.

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