Value of high-flow oxygen therapy after weaning for successful extubation of critical ill patients with mechanical ventilation / 中华危重病急救医学

Objective:To investigate the value of high-flow oxygen therapy after weaning in successful extubation of critically ill patients with mechanical ventilation.Methods:A retrospective study was conducted. The weaned patients who were older than 18 years old and underwent mechanical ventilation for the first time due to cerebrovascular accidents, surgical operations, cardiovascular diseases, and pneumonia admitted to the department of critical care medicine of Zhejiang Hospital from January 2018 to June 2020 were enrolled. Among the patients, 40 cases received high-flow oxygen therapy after weaning, and 37 cases received Venturi combined with the humidifier. The patient's gender, age, primary disease, severity score, duration of mechanical ventilation before weaning, heart rate (HR), blood pressure, pulse oxygen saturation (SpO 2) at 0, 6, 12, 18, and 24 hours after weaning, and pH value, arterial partial pressure of oxygen (PaO 2), arterial partial pressure of carbon dioxide (PaCO 2) at 6, 12, 18, and 24 hours after weaning, the rate of performing mechanical ventilation after weaning, extubation time after weaning, and the rate of reintubation after extubation for 72 hours were collected. Results:There was no significant difference in baseline data such as gender, age, primary disease, severity score, and duration of mechanical ventilation before weaning between the two groups. After weaning, the vital signs of the two groups were stable, and there was no significant difference in HR, systolic blood pressure (SBP), diastolic blood pressure (DBP) or SpO 2 at each time point between the two groups. After weaning, the pH of arterial blood gas analysis in the two groups and the fluctuations of PaO 2 and PaCO 2 in the high-flow group were not obvious. In the Venturi group, PaO 2 gradually decreased after weaning, PaCO 2 increased significantly at 12 hours, and slowly decreased after 12 hours. The PaO 2 from 6 hours and PaCO 2 from 12 hours in the high-flow group were significantly lower than those in the Venturi group, and continued to 24 hours [PaO 2 (mmHg, 1 mmHg≈0.133 kPa): 112.34±38.25 vs. 156.76±68.44 at 6 hours, 110.92±38.66 vs. 150.64±59.07 at 12 hours, 111.12±36.77 vs. 141.30±39.05 at 18 hours, 110.82±39.37 vs. 139.65±41.50 at 24 hours; PaCO 2 (mmHg): 41.30±7.51 vs. 47.42±7.54 at 12 hours, 40.97±6.98 vs. 45.83±8.63 at 18 hours, 40.10±7.06 vs. 46.14±9.15 at 24 hours, all P < 0.01]. The rate of performed mechanical ventilation after weaning and the rate of reintubation after extubation for 72 hours in the high-flow group were significantly lower than those in the Venturi group [17.5% (7/40) vs. 40.5% (15/37), 6.2% (2/32) vs. 31.8% (7/22), both P < 0.05], and the extubation time after weaning was significantly shorter than that in the Venturi group (hours: 22.43±11.72 vs. 28.07±10.42, P < 0.05). Conclusion:Using high-flow oxygen therapy to the extubation process of critically ill mechanical ventilation patients can reduce the incidence of carbon dioxide retention and the rate of performed mechanical ventilation after weaning, shorten the extubation time after weaning, and reduce the rate of reintubation after extubation for 72 hours.

Numerical simulation of a self-powered Fontan based on venturi effect / 中国胸心血管外科临床杂志

@#Objective    To investigate the effects of a self-powered conduit in different patients’ models who underwent extracardiac Fontan procedure. Methods    Four children who underwent extracardiac Fontan procedure in Shanghai Children's Medical Center from 2011 to 2017 year were selected. Venae cavae and pulmonary arteries were reconstructed using Mimics 19.0®. In silico, a venturi conduit was introduced to the anastomosis of venae cavae and pulmonary artery. Then computational fluid dynamics simulation was performed using patients’ clinical data. Results    When inferior venae cavae were directly to or to the left of superior venae cavae, the venturi conduit could assist the return of venous blood and reduce the pressures of venae cavae about 0.5 mm Hg. And the pressure differences between venae cavae and pulmonary arteries were about –0.7 mm Hg, which suggested that the conduit could generate right ventricle-like effect. Conclusion    The venturi conduit can reduce the pressure of venae cavae, increase pulmonary circulation flow and improve Fontan hemodynamics.

Network meta-analysis of airway humidification in patients with non-mechanical ventilation after domestic gastrectomy / 中国实用护理杂志

Objective@#To evaluate the therapeutic effects of various airway humidification methods to prevent pulmonary infection in non-mechanical ventilation patients by network meta-analysis.@*Methods@#The Pubmed, Embase, Web of Science, Wanfang data, and CNKI databases were searched and a randomized controlled trial (RCT) was developed for the method of humidification in non-mechanical ventilation patients after domestic air-surgery. The staff independently screened the literature, extracted the data, and used the stata14.0 software for network meta-analysis.@*Results@#In the 3 342 articles, 25 of them were included in the Meta-analysis, involving 6 methods of airway humidification. The order of effectiveness: first place in artificial nose, second in venturi humidification device, third in continuous atomization, Intermittent atomization ranked fourth, continued to drop into the fifth place, intermittently dropped into the sixth position of humidification.@*Conclusion@#The effectiveness of artificial nose device and venturi humidification device has been gradually recognized by domestic counterparts. Meta analysis shows that it is effective in preventing lung infection and worth promoting.

Application of Venturi combined with MR850 in ventilator offline patients with tracheotomy / 中华危重病急救医学

Objective To investigate the effect of oxygen therapy with Venturi combined with MR850 heating humidifier on patients without mechanical ventilation after tracheotomy. Methods Eighty patients (≥ 18 years old) who had undergone tracheotomy and without mechanical ventilation admitted to Fenyang Hospital of Shanxi Province from June 2016 to December 2017 were enrolled, and they were divided into control group and observation group according to random number table method, with 40 patients in each group. The observation group was given Venturi (removed the mask) combined with MR850 device active warm and humid oxygen therapy; the control group was given one-off ordinary flow device and warm and humid exchanger (artificial nose, HME) passive humid oxygen therapy. Body temperature increased by 1 ℃ above basal body temperature, white blood cell count (WBC) increased 2×109/L than the base value, oxygenation index (PaO2/FiO2) < 300 mmHg (1 mmHg = 0.133 kPa), airway mucosal hemorrhage, pulmonary infection and sputum viscosity were observed in the two groups for 5 days after oxygen therapy. Results Among the 80 patients, there were 46 males and 34 females, with an average age of (67.7±12.2) years. Compared with the control group, the incidence of increased body temperature (5.0% vs. 20.0%), the incidence of increased WBC (7.5% vs. 35.0%), the incidence of low PaO2/FiO2(2.5% vs. 7.5%), the incidence of airway mucosal bleeding (5.0 % vs. 15.0%) and the incidence of pulmonary infection (2.5% vs. 10.0%) were significantly decreased in the observation group (all P < 0.01), and the proportion of sputum viscosity Ⅰ degree of patients was significantly increased (57.5% vs. 12.5%, P < 0.01). Conclusion Venturi combined with MR850 device can effectively control airway temperature and humidity, promote sputum dilution and conducive to drainage, reduce pulmonary infection in adults patients without mechanical ventilation after tracheotomy, thereby reducing postoperative complications of tracheotomy.

Study on the accuracy of oxygen concentration of modified oxygen treatment with Venturi and humidity system / 中华危重病急救医学

Objective@#To verify the accuracy of oxygen concentration (FiO2) of modified oxygen treatment with Venturi and humidity system.@*Methods@#Patients just after ventilator weaning and before the removal of tracheal intubation/tracheotomy tube, who admitted to the intensive care unit (ICU) of Henan Provincial People's Hospital from May 1st to December 15th in 2017, were enrolled. All patients were given a modified oxygen treatment with Venturi and humidity system, and the oxygen flow rate (Flow) of the Venturi device and the oretical value of FiO2 were adjusted according to the patient's condition. Patients were divided into five groups based on doctor's orders: Flow 3 L/min FiO2 0.24, Flow 3 L/min FiO2 0.26, Flow 6 L/min FiO2 0.28, Flow 6 L/min FiO2 0.30, Flow 9 L/min FiO2 0.35. The value of FiO2 at the inhalation end of patients of each group was measured by TSI airflow analyzer, and the consistency between the measured value of FiO2 at the inhalation end and the FiO2 marked value of Venturi was compared and analyzed.@*Results@#When the FiO2 theoretical value of Venturi were adjusted to 0.24, 0.26, 0.28, 0.30, and 0.35, the measured values of FiO2 at the inhalation end of patients were 0.38±0.05, 0.38±0.05, 0.40±0.04, 0.41±0.04, and 0.77±0.11, respectively, which were all significantly higher than the theoretical value of FiO2 (all P < 0.01). The difference between the measured value of FiO2 at the inhalation side and the FiO2 value of the Venturi annotated and the difference rate were both "V"-shaped, both of which decreased with the increase in theoretical value of FiO2 to a Flow of 9 L/min and a theoretical value of FiO2 0.35, the accuracy was the worst, with the FiO2 difference of 0.42±0.11, and the FiO2 difference rate of (121.6±36.5)%.@*Conclusion@#There is a difference between the measured value and the theoretical value of FiO2 at the inhalation end of the modified Venturi oxygen therapy humidification system, which needs to be paid attention to during clinical oxygen therapy.

Avaliação de lavador de gases do tipo Venturi, operando com solução de hidróxido de sódio, para dessulfuração de biogás com altas concentrações de H2S / Evaluation of a Venturi gas scrubber operating with sodium hydroxide solution for desulphurization of biogas with high H2S concentrations

RESUMO O processo de metanização tem sido empregado com sucesso como tratamento biológico de distintas tipologias de efluentes orgânicos. Para conversão do biogás em energia, o sulfeto de hidrogênio (H2S) é o principal composto a ser removido. A metanização da vinhaça, principal efluente do setor sucroenergético, gera um biogás com concentrações de H2S que podem ultrapassar os 30.000 ppmV, com grande variação devido às condições operacionais das usinas. Processos químicos de dessulfuração apresentam-se como uma alternativa que alia robustez e maior controle operacional do processo, além de não resultarem em diluição da concentração de metano, como ocorre em processos biológicos. Entretanto, a principal desvantagem desses processos é a demanda de compostos químicos, resultando em custos operacionais elevados. Esse trabalho teve como objetivo avaliar a viabilidade técnica de se realizar uma dessulfuração química de biogás com altas concentrações de H2S, além de determinar as concentrações de hidróxido de sódio (NaOH) em meio aquoso que proporcionassem altas eficiências de remoção de H2S e que possibilite que o efluente desse processo seja passível de regeneração por microrganismos sulfo-oxidantes. Foi utilizado um lavador do tipo Venturi, com uma solução de 5,00 x 10-2 mol.L-1 de NaOH. Na faixa de pH de crescimento desses microrganismos, as eficiências de remoção de H2S variaram de 99,3 a 99,9%. Constatou-se que é possível atingir eficiências máximas de remoção de H2S utilizando soluções de 5,00 x 10-3 mol.L-1 de NaOH, obtendo um efluente com pH adequado ao crescimento de microrganismos sulfo-oxidantes. Verificou-se, ainda, que o CO2 exerce grande influência na competição pelas hidroxilas presentes no meio.

ABSTRACT The methanation process has been successfully used as a biological treatment method for different effluent typologies. For biogas to energy conversion, the hydrogen sulfide (H2S) is the most important compound that must be removed. The methanation of vinasse, which is the major effluent of the sugar and ethanol industry, results in a biogas with hydrogen sulfide concentrations that might exceed 30,000 ppmV. The concentrations may vary considerably according to the operational conditions of the production process. Chemical desulphurization processes are presented as an alternative that combines robustness and provides better operational process control. Moreover, the chemical desulphurization does not result in dilution of the methane concentration, which is side effect noticed in the biological desulphurization processes. However, the main disadvantage of the chemical desulphurization is exactly the high demand for chemical compounds, which results in high operational costs. The present research investigated the technical feasibility of applying a chemical desulphurization process to treat biogas with high hydrogen sulfide concentrations; the research also aimed to determine the sodium hydroxide (NaOH) concentration in the aqueous medium, as the NaOH presence enables high efficiency of hydrogen sulfide removal and allows the effluent regeneration by sulfo-oxidant microorganisms. The experiments were carried out using a Venturi absorption tower with a NaOH chemical solution of 5.00 x 10-2 mol.L-1. In the pH range favorable to this microorganisms, the H2S removal efficiency varied from 99.3 to 99.9%. It was observed that it is possible to achieve maximum efficiency of removal of H2S using solutions of 5.00 x 10-3 mol.L-1 NaOH, obtaining an effluent with proper pH to grow sulfo oxidant microorganisms. Moreover, it was verified that carbon dioxide significantly influenced the competition for the hydroxyls present in the solution.

Application observation of venturi oxygen therapy heated humidify system on artificial airway management / 中国实用护理杂志

Objective To investigate the clinic application of venturi oxygen therapy heated humidify system on artificial airway management. Methods 30 cases of experimental group used venturi oxygen therapy for humidification and heating, while 30 cases of control group were treated with continuous wet micro-injection pump method for artificial airway care. Humidifying effects, effects of oxygen therapy, incidence of pulmonary complications were compared between the two groups. Results The humidifying effects on experimental group (26 cases) were better than control group (17 cases) (χ2=6.648,P<0.05). The irritating cough (5 cases), airway mucosa injury (1 case) and the formation of sputum crust (2 cases) in experimental group were less than 13 cases, 6 cases, 6 cases in control group (χ2=5.079, 4.043, 7.954,P<0.05). The times of sputum drainage on experimental group was (17.28 ± 5.51) times which was less than (31.22±5.24) times of control group (t=4.312, P<0.01).The effect on oxygen therapy about oxygen saturation in experimental group was 0.932 2 ±0.020 5 when sputum drainage, and 0.982 2± 0.009 4 two minutes later, which was higher than 0.916 7 ±0.011 2 and 0.957 2 ±0.013 6 of control group (t=3.431,6.276, P<0.01). Conclusions Venturi oxygen therapy heated humidify system can reduce the formation of sputum crust, reduce the times of sputum drainage, reduce hypoxia degree and shorten the duration caused by sputum crust, improve the effect of heat and humidification of patient.

Estudio de dos sistemas de transporte para mantener la viabilidad de bacterias de interés clínico / Study of the ability of two swab transport systems to maintain viability of clinically important bacteria / Estudo de dois sistemas de transporte para manter a viabilidade de bactérias de interesse clínico

Se compararon dos dispositivos de conservación de muestras tomadas por hisopado con cepas de referencia de Streptococcus pyogenes, Haemophilus influenzae, Neisseria gonorrhoeae y Streptococcus pneumoniae (ambos con medio de Stuart). El dispositivo Copan Venturi Transystem® (Copan Italia Spa, Brescia, Italia) resultó ser significativamente más efectivo que el Eurotubo (Deltalab, Rubí, Barcelona, España) probablemente porque la estrangulación que presenta al comienzo de la columna semisólida (sistema tipo Venturi) permitiría una mejor conservación de los microorganismos.

Two extendedly-used swab transport devices with Stuart medium using Streptococcus pyogenes, Haemophilus influenzae, Neisseria gonorrhoeae and Streptococcus pneumoniae reference strains, were compared. Copan Venturi Transystem® (Copan Italia Spa, Brescia, Italy) was significantly more effective than Eurotubo (Deltalab, Rubí, Barcelona, Spain), probably because the narrowing of the tube, just at the beginning of the semisolid column (Venturi system), would yield a better conservation of diffrerent organisms.

Foram comparados dois dispositivos de conservação de amostras tomadas por swab com cepas de referência de Streptococcus pyogenes, Haemophilus influenzae, Neisseria gonorrhoeae e Streptococcus pneumoniae (ambos com meio de Stuart). O dispositivo Copan Venturi Transystem® (Copan Italia Spa, Brescia, Itália) resultou ser significativamente mais efetivo que o Eurotubo (Deltalab, Rubí, Barcelona, Espanha) provavelmente porque o estrangulamento que apresenta no início da coluna semi-sólida (sistema tipo Venturi) permitiria uma melhor conservação dos microorganismos.