Airway humidification therapy for pertussis in infants / 中国基层医药

Objective:To investigate the effects of airway humidification therapy on pertussis in infants.Methods:Sixty children with pertussis who received treatment in Wenzhou Hospital of Integrated Traditional Chinese and Western Medicine from May 2020 to September 2021 were included in this study. They were randomly divided into study and control groups, with 30 infants per group. The control group was treated with conventional drugs. The study group was subjected to airway humidification therapy based on conventional drug treatment. Clinical efficacy was evaluated in each group. Time to an improvement in clinical symptoms and length of hospital stay were recorded. Lung function indicators and serum inflammatory factor levels were determined before and after treatment. Pertussis-related complications were recorded.Results:The overall response rate in the study group was significantly higher than that in the control group (100.00% vs. 76.7%, χ2 = 5.82, P = 0.016). Time to disappearance of spastic cough, time to resolution of cyanosis, time to disappearance of pulmonary rales, and length of hospital stay in the study group were (3.10 ± 0.67) days, (1.53 ± 0.68) days, (4.27 ± 0.58) days, and (11.57 ± 0.73) days, respectively, which were significantly shorter than (4.23 ± 1.99) days, (2.67 ± 1.77) days, (5.63 ± 2.38) days, (13.33 ± 2.40) days ( t = 2.93, 3.27, 3.04, 3.86; P = 0.005, 0.002, 0.003, P < 0.001). Respiratory rate in the study group was significantly lower than that in the control group [(21.83 ± 1.15) breaths/minute vs. (24.23 ± 3.12) breaths/minute, t = 3.94, P = 0.002]. Tidal volume/kg body weight, the ratio of time to peak expiratory flow to total expiratory time and the ratio of volume to peak expiratory flow to total expiratory volume in the study group were (10.70 ± 0.81) mL/kg, (41.60 ± 1.57)%, (42.89 ± 1.44)%, respectively, which were significantly higher than (9.78 ± 1.34) mL/kg, (39.18 ± 3.37)%, (40.20 ± 3.05)% in the control group ( t = 3.21, 3.56, 4.36; P < 0.001, P = 0.001, P < 0.001). Serum tumor necrosis alpha (TNF-α), interleukin-6 and interleukin-8 levels in the study group were (62.44 ± 2.96) ng/L, (46.59 ± 1.96) ng/L, (54.63 ± 3.27) ng/L, respectively, which were significantly lower than (79.86 ± 3.30) ng/L, (58.20 ± 2.10) ng/L, (63.31 ± 3.86) ng/L in the control group ( t =21.53, 22.13, 9.38, all P < 0.001). The overall incidence of pertussis in the study group was significantly lower than that in the control group (3.3% vs. 26.7%, χ2 = 4.71, P = 0.030). Conclusion:Airway humidification therapy can shorten the time to reduction of symptoms of spasmodic pertussis, improve clinical efficacy, strengthen pulmonary ventilation function, lower respiratory tract inflammatory responses and reduce the risk of pertussis-related complications.

O Teste do Degrau de Seis Minutos como Preditor de Capacidade Funcional de Acordo com o Consumo de Oxigênio de Pico em Pacientes Cardíacos / The Six-Minute Step Test as a Predictor of Functional Capacity according to Peak VO2 in Cardiac Patients

Resumo Fundamento: O teste do degrau de seis minutos (TD6) é uma forma simples de avaliar a capacidade funcional, embora tenha sido pouco estudado em pacientes com doença arterial coronariana (DAC) ou insuficiência cardíaca (IC). Objetivo: Analisar a associação entre o TD6 e o consumo de oxigênio de pico (VO2pico) e desenvolver uma equação que estime o VO2pico com base no TD6, bem como determinar um ponto de corte para o TD6 que preveja um VO2pico ≥ 20 mL.kg-1.min-1 Métodos: Nos 171 pacientes submetidos ao TD6 e a um teste de exercício cardiopulmonar, análises da curva ROC, de regressão e de correlação foram usadas, e um p < 0,05 foi admitido como significativo. Resultados: A idade média foi 60±14 anos, e 74% eram do sexo masculino. A média da fração de ejeção ventricular esquerda foi 57±16%; 74% apresentavam DAC, e 28%, IC. A média do VO2pico foi 19±6 mL.kg-1.min-1, e o desempenho médio do TD6 foi 87±45 passos. A associação entre o TD6 e o VO2pico foi r 0,69 (p < 0,001). Os modelos VO2pico = 19,6 + (0,075 x TD6) - (0,10 x idade) para homens e VO2pico = 19,6 + (0,075 x TD6) - (0,10 x idade) - 2 para mulheres poderiam prever o VO2pico com base nos resultados do TD6 (R ajustado 0,72; R2 ajustado 0,53). O ponto de corte mais acurado para que o TD6 preveja um VO2pico ≥ 20 mL.kg-1.min-1 foi de > 105 passos [área sob a curva 0,85; intervalo de confiança de 95% 0,79 - 0,90; p < 0,001]. Conclusão: Uma equação que preveja o VO2pico com base nos resultados do TD6 foi derivada, e foi encontrada uma associação significativa entre o TD6 e o VO2pico. O ponto de corte do TD6, que prevê um VO2pico ≥ 20 mL.kg-1.min-1, foi > 105 passos. (Arq Bras Cardiol. 2021; 116(5):889-895)

Abstract Background: Six-minute step test (6MST) is a simple way to evaluate functional capacity, although it has not been well studied in patients with coronary artery disease (CAD) or heart failure (HF). Objective: Analyze the association between the 6MST and peak oxygen uptake (VO2peak) and develop an equation for estimating VO2peak based on the 6MST, as well as to determine a cutoff point for the 6MST that predicts a VO2peak ≥20 mL.Kg-1.min-1 Methods: In 171 patients who underwent the 6MST and a cardiopulmonary exercise test, correlation, regression, and ROC analysis were used and a p < 0.05 was admitted as significant. Results: mean age was 60±14 years and 74% were male. Mean left ventricle ejection fraction was 57±16%, 74% had CAD and 28% had HF. Mean VO2peak was 19±6 mL.Kg-1.min-1 and mean 6MST performance was 87±45 steps. Association between 6MST and VO2peak was r 0.69 (p <0.001). The model VO2peak =19.6 + (0.075 x 6MST) - (0.10 x age) for men and VO2peak =19.6 + (0.075 x 6MST) - (0.10 x age) - 2 for women could predict VO2peak based on 6MST results (adjusted R 0.72; adjusted R2 0.53). The most accurate cutoff point for 6MST to predict a VO2peak ≥20 mL.Kg-1.min-1 was >105 steps (AUC 0.85; 95% CI 0.79 -0.90; p <0.001). Conclusion: An equation for predicting VO2peak based on 6MST results was derived, and a significant association was found between 6MST and VO2peak. The cutoff point for 6MST, which predicts a VO2peak ≥20 mL.Kg-1.min-1, was >105 steps. (Arq Bras Cardiol. 2021; 116(5):889-895)

Equations for calculating ideal body weight in patients on mechanical ventilation in adult intensive care units in Latin America: exploratory review / Ecuaciones para calcular el peso ideal en pacientes con ventilación mecánica en unidades de cuidado intensivo adulto en Latinoamérica: revisión exploratoria

Abstract Introduction Ideal body weight calculation is used in critical medicine for drug dosing and setting ventilation parameters. However, the suggested and used equations were designed on the basis of anthropometric variables that do not represent the Latin American population. Objective To map and present the current evidence on the equations used to calculate ideal weight in patients on mechanical ventilation in intensive care units in Latin America. Material and Methods Exploratory review using the Joanna Briggs Institute method conceived by Arskey / O'Malley. A search was performed in the BVS, LILLACS, REDALYC, Ovid, Google Scholar and Scielo databases using keywords and MeSH terms in Spanish, English, and Portuguese, with no time limitation. The results are presented in descriptive tables. Results Overall, 1126 studies were identified and 1120 were excluded; 6 studies were reviewed and 3 additional studies were identified through a manual search. The studies were published in Chile, Brazil, Mexico, Ecuador, and Peru. In 89%, the ARDS Network equation was used to calculate tidal volume. Acute respiratory distress syndrome was the most reported pathology (33%). Conclusions Adult intensive care units in Latin America use the equation suggested by the ARDS Network, which was designed in a population with different anthropometric characteristics.

Resumen Introducción El cálculo del peso ideal se utiliza en medicina crítica para dosificación de medicaciones y programación de parámetros ventilatorios; sin embargo, las ecuaciones sugeridas y usadas fueron diseñadas con variables antropométricas que no representan la población latinoamericana. Objetivo Mapear y presentar la evidencia actual de las ecuaciones utilizadas para calcular el peso ideal en pacientes con ventilación mecánica en unidades de cuidado intensivo de Latinoamérica. Material y métodos Revisión exploratoria con el método del Instituto Joanna Briggs concebido por Arskey y O'Malley. Se realizó una búsqueda en las bases de datos BVS, LILACS, Redalyc, Ovid, Google Scholar y SciELO con el uso de palabras clave y términos MeSH en idiomas español, inglés y portugués, sin límites de tiempo. Los resultados se presentan de forma descriptiva. Resultados Se identificaron 1.126 estudios, se excluyeron 1.120, se revisaron seis y se encontraron tres adicionales mediante búsqueda manual. Los estudios fueron publicados en Chile, Brasil, México, Ecuador y Perú. En el 89 % se usó la ecuación del ARDS Network para calcular volumen corriente. El síndrome de dificultad respiratoria aguda fue la patología más informada (33 %). Conclusiones En las unidades de cuidado intensivo adulto de Latinoamérica se usa la ecuación sugerida por el ARDS Network diseñada en población con características antropométricas diferentes.

Ability of adjusted pulse pressure variation in predicting fluid responsiveness in spontaneously breathing patients with sepsis / 中华急诊医学杂志

Objective:To investigate the effect of tidal volume (Vt DI) on pulse pressure variation (ΔPP DI) during deep inspiration maneuvers in spontaneously breathing patients with sepsis and to test if adjusting ΔPP DI by Vt DI can further improve its ability in predicting fluid responsiveness (FR). Methods:Spontaneously breathing, nonintubated sepsis or septic shock patients who were admitted to the Intensive Care Unit of the Characteristic Medical Center of Chinese People's Armed Police Force and Nanjing Gaochun People's Hospital were prospectively enrolled from October 2017 to October 2019. Volume expansion (VE) was performed by infusing 500 mL saline over 20 min. Prior to VE, measurements including pulse pressure variation and tidal volume were obtained during quiet spontaneous breathing (ΔPP TB and Vt TB, respectively) and during the deep inspiration maneuver (ΔPP DI and Vt DI, respectively). Patients were classified as responders if stroke volume (SV) increased ≥ 15% after VE, otherwise non-responders. Multiple linear regression analysis was conducted to investigate the correlation of ΔPP DI with Vt DI and VE-induced percentage changes in SV (ΔSV). Receiver operating characteristic (ROC) curve analysis and the gray zone approach were used to assess the ability of each index to predict FR. Changes in gray zone limits according to the cost ratio (R = cost[false positive (FP)]/cost[false negative (FN)]) were also evaluated. Results:Of the included 31 patients, 17 were responders. There was no significant difference in ΔPP TB between fluid responders and non-responders ( P>0.05), whereas ΔPP DI was significantly higher in responders than in non-responders [(19.1±7.4)% vs (11.2±4.5)%; P=0.001]. The area under the ROC curve (AUC) of ΔPP DI predicted FR was 0.832, sensitivity of 76.47% and specificity of 71.43%, which was significantly higher than ΔPP TB (AUC=0.580, sensitivity of 47.06% and specificity of 71.43%; P<0.05). Multiple linear regression analysis showed that both Vt DI and ΔSV were independently associated with ΔPP DI ( P<0.01), the AUC of ΔPP DI adjusted by Vt DI was signigicantly higher than that of ΔPP DI alone ( P=0.03). Among the ΔPP TB, ΔPP DI and ΔPP DI/Vt DI, ΔPP DI/Vt DI had the narrowest gray zone (12.7-14.5) for the normal fluid policy (R=1), which only included 19% of the patients. When applying "restrictive" fluid management (R=2), the gray zone for ΔPP DI/Vt DI was 12.8-14.5 and included only 2 patients (6.5%). Conclusions:In spontaneously breathing, nonintubated patients with sepsis or septic shock, the ΔPP value obtained during the deep inspiration maneuver predicts FR with moderate accuracy. Given the close correlation between Vt DI and ΔPP DI, ΔPP DI adjusted by Vt DI performs better than ΔPP DI alone in predicting FR.

Protective mechanical ventilation in patients with risk factors for ARDS: prospective cohort study / Ventilação mecânica protetora em pacientes com fator de risco para SDRA: estudo de coorte prospectiva

ABSTRACT Objective: To evaluate the association that protective mechanical ventilation (MV), based on VT and maximum distending pressure (MDP), has with mortality in patients at risk for ARDS. Methods: This was a prospective cohort study conducted in an ICU and including 116 patients on MV who had at least one risk factor for the development of ARDS. Ventilatory parameters were collected twice a day for seven days, and patients were divided into two groups (protective MV and nonprotective MV) based on the MDP (difference between maximum airway pressure and PEEP) or VT. The outcome measures were 28-day mortality, ICU mortality, and in-hospital mortality. The risk factors associated with the adoption of nonprotective MV were also assessed. Results: Nonprotective MV based on VT and MDP was applied in 49 (42.2%) and 38 (32.8%) of the patients, respectively. Multivariate Cox regression showed that protective MV based on MDP was associated with lower in-hospital mortality (hazard ratio = 0.37; 95% CI: 0.19-0.73) and lower ICU mortality (hazard ratio = 0.40; 95% CI: 0.19-0.85), after adjustment for age, Simplified Acute Physiology Score 3, and vasopressor use, as well as the baseline values for PaO2/FiO2 ratio, PEEP, pH, and PaCO2. These associations were not observed when nonprotective MV was based on the VT. Conclusions: The MDP seems to be a useful tool, better than VT, for adjusting MV in patients at risk for ARDS.

RESUMO Objetivo: Avaliar a associação da ventilação mecânica (VM) protetora, com base no VT e na pressão de distensão máxima (PDM), com a mortalidade em pacientes com fator de risco para SDRA. Métodos: Este estudo de coorte prospectivo foi conduzido em uma UTI e incluiu 116 pacientes em VM que apresentavam pelo menos um fator de risco para o desenvolvimento de SDRA. Os parâmetros ventilatórios foram coletados duas vezes ao dia durante sete dias, e os pacientes foram divididos em dois grupos (VM protetora e VM não protetora) com base na PDM (diferença entre pressão máxima de vias aéreas e PEEP) ou no VT. Os desfechos foram mortalidade em 28 dias, mortalidade na UTI e mortalidade hospitalar. Os fatores de risco associados com a adoção da VM não protetora também foram avaliados. Resultados: A VM não protetora com base no VT e na PDM ocorreu em 49 (42,2%) e em 38 (32,8%) dos pacientes, respectivamente. A regressão multivariada de Cox mostrou que a VM protetora com base na PDM associou-se a menor mortalidade hospitalar (hazard ratio = 0,37; IC95%: 0,19-0,73) e em UTI (hazard ratio = 0,40; IC95%, 0,19-0,85), após ajuste para idade, Simplified Acute Physiology Score 3, uso de vasopressor e valores basais de PaO2/FiO2, PEEP, pH e PaCO2. Essas associações não foram observadas quando a VM não protetora foi baseada no VT. Conclusões: A PDM parece ser uma ferramenta útil, melhor do que o VT, para o ajuste da VM em pacientes sob risco para SDRA.

Índices de oxigenación en los pacientes neuroquirúrgicos utilizando dos estrategias ventilatorias en el perioperatorio / Index of oxygenation in neurosurgical patients using two ventilatory strategies on the perioperatory / Índices de oxigenação em pacientes neurocirúrgicos utilizando duas estratégias ventilatórias no perioperatório

Resumen: Introducción: La comorbilidad pulmonar postoperatoria dependerá de factores relacionados con el paciente, modificables y no modificables, pero definitivamente los parámetros ventilatorios intraoperatorios tienen un rol fundamental. Existen índices de oxigenación (IO) que pueden resultar útiles en la evaluación del grado de lesión pulmonar. Material y métodos: Estudio prospectivo, descriptivo, analítico, de casos y controles. Pacientes que requirieron intervención neuroquirúrgica (urgente o electiva) y ventilación mecánica invasiva para el procedimiento. Durante el periodo comprendido entre el 1o de enero de 2018 al 31 de diciembre de 2018. Los pacientes que cumplieron con los criterios de inclusión se asignaron uno a uno para pertenecer al grupo Vt Intermedio (> 8 a < 10 mL/kg peso predicho) o al grupo Vt Bajo (6-8 mL/kg peso predicho). La PEEP fue determinada a consideración del médico (anestesiólogo). Resultados: En el periodo considerado se incluyeron 60 pacientes, los cuales cumplieron con los criterios de inclusión. Del total, 30 pacientes se incluyeron en el grupo Vt Intermedio (VtI) y 30 pacientes en el grupo Vt Bajo (VtB). La modalidad ventilatoria más utilizada fue asisto-control-volumen (ACV) con 96.7% para VtI y 100% para VtB con p = 0.3. El Vt por peso predicho en el grupo de VtI tuvo una media de 8.9 mL/kg y en el grupo de VtB una media de 7.1 mL/kg con una p = 0.001. La escala de coma de Glasgow (ECG) posterior a la extubación fue de 14.3 puntos y 14.4 puntos para VtI y VtB sin diferencia estadísticamente significativa. Conclusión: Utilizar volumen corriente intermedio (> 8 a < 10 mL/kg peso predicho) en los pacientes neuroquirúrgicos ocasiona alteración de los índices de oxigenación: PaO2/FiO2 y PaO2/PAO2. El nivel de PEEP durante el perioperatorio de los pacientes neuroquirúrgicos no ocasiona diferencia significativa en la escala de coma de Glasgow.

Abstract: Introduction: Postoperative pulmonary comorbidity will depend on factors related to the patient, modifiable and non-modifiable, but intraoperative ventilatory parameters definitely play a fundamental role. There are oxygenation indices (OI) that may be useful in assessing the degree of lung injury. Material and methods: Prospective, descriptive, analytical, case-control study. Patients who required neurosurgical intervention (urgent or elective) and invasive mechanical ventilation for the procedure. During the period from January 1, 2018 to December 31, 2018. Patients who met the inclusion criteria were assigned 1 to 1 to belong to the Intermediate Tidal Volumen group (ItV) (> 8 to < 10 mL/kg predicted weight) or to the Low Tidal Volumen group (LtV) (6-8 mL/kg predicted weight). PEEP was determined for the doctor's consideration (anesthesiologist). Results: In the period considered, 60 patients were included who met the inclusion criteria. Of the total, 30 patients were included in the ItV group and 30 patients in the LtV group. The most commonly used ventilatory modality was asysto-control-volume (ACV) with 96.7% for ItV and 100% for LtV with p = 0.3. The predicted weight tV in the ItV group had an average of 8.9 mL/kg and in the LtV group an average of 7.1 mL/kg with a p = 0.001 The Glasgow coma scale (GCE) after extubation was of 14.3 points and 14.4 points for ItV and LtV without statistically significant difference. Conclusion: Using intermediate tidal volume (> 8 to < 10 mL/kg predicted weight) in neurosurgical patients, causes alteration of oxygenation rates: PaO2/FiO2 and PaO2/PAO2. The level of PEEP during the perioperative period of neurosurgical patients does not cause a significant difference in the Glasgow coma scale.

Resumo: Introdução: A comorbidade pulmonar pós-operatória vai depender de fatores relacionados ao paciente, modificáveis e não modificáveis, mas os parâmetros ventilatórios intra-operatórios certamente têm papel fundamental. Existem índices de oxigenação (IO) que podem ser úteis na avaliação do grau de lesão pulmonar. Material e métodos: Estudo prospectivo, descritivo, analítico, caso-controle. Pacientes que necessitaram de intervenção neurocirúrgica (urgente ou eletiva) e ventilação mecânica invasiva para o procedimento. Durante o período de 1o de janeiro de 2018 a 31 de dezembro de 2018. Os pacientes que preencheram os critérios de inclusão foram designados de 1 a 1 para pertencer ao grupo Vt Intermediário (> 8 a < 10 mL/kg de peso previsto) ou para o grupo Vt Baixo (6-8 mL/kg de peso previsto). A PEEP foi determinada por consideração do médico (anestesiologista). Resultados: No período considerado, foram incluídos 60 pacientes que atenderam aos critérios de inclusão. Do total, 30 pacientes foram incluídos no grupo Vt Intermediário (VtI) e 30 pacientes no grupo Vt Baixo (VtB). A modalidade ventilatória mais utilizada foi o volume assistido-controlado (VAC) com 96.7% para VtI e 100% para VtB com p = 0.3. O Vt previsto em peso no grupo VtI teve média de 8.9 mL/kg e no grupo VtB média de 7.1 mL/kg com p = 0.001. A escala de coma de Glasgow (ECG) após a extubação foi de 14.3 pontos e 14.4 pontos para VtI e VtB sem diferença estatisticamente significativa. Conclusão: O uso de volume corrente intermediário (> 8 a < 10 mL/kg de peso previsto) em pacientes neurocirúrgicos causa alteração nos índices de oxigenação: PaO2/FiO2 e PaO2/PAO2. O nível de PEEP durante o período perioperatório de pacientes neurocirúrgicos não causa diferença significativa na escala de coma de Glasgow.

The Effects of Open-Lung Strategy on Lung Injury Markers in Patients under General Anesthesia with Low-tidal-volume Ventilation / 中山大学学报(医学科学版)

@#【Objective】To determine the effects of an open-lung strategy（OLS）comprising moderate positive end- expiratory pressure （PEEP） and intermittent recruitment manoeuvres（RMs） on plasma levels of lung epithelial injury markers［i.e. soluble receptor for advanced glycation end products（sRAGE）and Clara cell protein（CC16）］during low- tidal-volume ventilation for surgery.【Methods】One hundred patients who were undergoing laparoscopic colorectal cancer resection under low-tidal-volume ventilation were enrolled in this study. They were randomly assigned（1∶1）to the OLS group（using PEEP of 6~8 cmH2O and intermittent RM），or the NOLS group（without using PEEP and RM）. Blood samples were taken before anesthesia induction（T1），immediately after surgery（T2）and the postoperative day 3（T3）to measure the plasma concentrations of sRAGE and CC16. 【Results】 Significant differences were not observed in the concentrations of sRAGE and CC16 at T1，T2 and T3 between the two groups（all P > 0.05）. For all the enrolled patients， the concentrations of sRAGE at T2 and T3 were higher than that at T1，the concentration of sRAGE at T3 was higher than that at T2，and the concentration of CC16 at T3 was higher than that at T1 and T2（all P < 0.05）.【Conclusions】In patients under general anesthesia with low-tidal-volume ventilation，the using of an OLS comprising medium PEEP and intermittent RMs can not alter plasma levels of lung epithelial injury markers（sRAGE and CC16）in three days after surgery.

Inhalation Induction Using Sevoflurane in Children, The Single Breath Vital Capacity Technique Compared to Tidal Volume Technique

Introduction: The low solubility as well as the absence ofpungency facilitates rapid induction by facemask, makingsevoflurane the anesthetic of first choice for inhalationalinduction in children. The aim of our study was to comparethe efficacy and tolerance and to compare the inductioncharacteristics of sevoflurane by vital capacity and tidalvolume techniques.Material and methods: Our study included 30 patients eachin both group’s i.e. single breath vital (VC) capacity and tidalvolume groups (TV). The mean age in VC group was 8.76years and in TV group was 8.86 years. We mainly comparedthe Induction time, hemodynamic changes and adverse eventsin both the techniques using sevoflurane.Results: The heart rate, systolic blood pressure, diastolicblood pressure and the mean arterial pressure were comparedbetween both the groups. All these parameters were takenbefore induction, after loss of eyelash reflex and up to 10minutes at 2 minute intervals. There were minimal changesbetween the two groups but clinically, they are not statisticallysignificant in view of mean blood pressure whereas weobserved statistically significant difference in heart rate at8minutes in the post induction period which resolved later. Inour study, we observed an increased incidence of cough andinvoluntary movements in T V. group compared to V C groupbut statistically, there is no significant difference.Conclusion: Sevoflurane Induction improved the speedof induction when compared to tidal volume technique andreduced the incidence of induction complications

Tidal volume in mechanically ventilated dogs: can human strategies be extrapolated to veterinary patients?

This paper compares and describes the tidal volume (Vt) used in mechanically ventilated dogs under a range of clinical conditions. Twenty-eight dogs requiring mechanical ventilation (MV) were classified into 3 groups: healthy dogs mechanically ventilated during surgery (group I, n = 10), dogs requiring MV due to extra-pulmonary reasons (group II, n = 7), and dogs that required MV due to pulmonary pathologies (group III, n = 11). The median Vt used in each group was 16 mL/kg (interquartile range [IQR], 15.14–21) for group I, 12.59 mL/kg (IQR, 9–14.25) for group II, and 12.59 mL/kg (IQR, 10.15–14.96) for group III. The Vt used was significantly lower in group III than in group I (p = 0.016). The thoraco-pulmonary compliance was significantly higher in group I than in groups II and III (p = 0.011 and p = 0.006, respectively). The median driving pressure was similar among the groups with a median of 9, 11, and 10 cmH2O in groups I, II, and III, respectively (p = 0.260). Critically-ill dogs requiring MV due to the primary pulmonary pathology received a significantly lower Vt than healthy dogs but with a range of values that were markedly higher than those recommended by human guidelines.

Respiratory support in patients with acute respiratory distress syndrome:an expert opinion interpretation / 中国小儿急救医学

Acute respiratory distress syndrome (ARDS) is a common disease in intensive care unit. ARDS has attracted wide attention of clinicians for its high in-hospital mortality and high incidence of long-term mortality. This expert opinion reviews the available clinical evidence and adjuvant treatment of ventilator support. Based on clinical evidence and experience,we provide suggestions for the management of patients with ARDS. We interpret this expert opinion and some experience in children was added,hoping to provide suggestions for the treatment of children with ARDS.

Evaluation of volume responsiveness by pulse pressure variability and inferior vena cava dispensability index at different tidal volumes by mechanical ventilation

This study investigated the effects of tidal volume (TV) on the diagnostic value of pulse pressure variation (PPV) and the inferior vena cava dispensability index (IVC-DI) for volume responsiveness during mechanical ventilation. In patients undergoing elective surgery with mechanical ventilation, different TVs of 6, 9, and 12 mL/kg were given for two min. The left ventricular outflow tract velocity-time integral (VTI) was measured by transthoracic echocardiography. The IVC-DI was measured at sub-xyphoid transabdominal long axis. The PPV was measured via the radial artery and served as baseline. Index measurements were repeated after fluid challenge. VTI increased by more than 15% after fluid challenge, which was considered as volume responsive. Seventy-nine patients were enrolled, 38 of whom were considered positive volume responsive. Baseline data between the response group and the non-response group were similar. Receiver operating characteristic curve confirmed PPV accuracy in diagnosing an increase in volume responsiveness with increased TV. When TV was 12 mL/kg, the PPV area under the curve (AUC) was 0.93 and the threshold value was 15.5%. IVC-DI had the highest diagnostic accuracy at a TV of 9 mL/kg and an AUC of 0.79, with a threshold value of 15.3%. When TV increased to 12 mL/kg, the IVC-DI value decreased. When the TV was 9 and 12 mL/kg, PPV showed improved performance in diagnosing volume responsiveness than did IVC-DI. PPV diagnostic accuracy in mechanically ventilated patients was higher than IVC-DI. PPV accuracy in predicting volume responsiveness was increased by increasing TV.

Research progress in perioperative ventilator-induced lung injury / 中南大学学报(医学版)

Lung-protective ventilation (such as low tidal volume and application of positive end-expiratory pressure) is beneficial for patients with acute lung injury or acute respiratory distress syndrome (ARDS) and has become the standard treatment in intensive care unit (ICU).However,some experts now question whether the protective ventilation strategy for ARDS patients in the ICU is equally beneficial for patients after surgery,especially for most patients without any pre-existing lung lesions.This review will discuss preoperative,intraoperative,and postoperative lung protection strategies to reduce the risk of complications associated with anesthesia.

The Effects of Chest Physiotherapy on Applied to Patients Mechanicalventilated: In Patients with Acute Lung Injury / 중환자간호학회지

PURPOSE: The purpose of this study was to examine the effects of two single chest physiotherapies mechanically ventilated patients with acute lung injury.METHOD: Participants were 30 ICU patients depending entirely on ventilators without self-respiration. Each patients received two single chest physiotherapiesvibration palm cup percussion at hour intervals. Data were analyzed one-way ANOVA and Wilcoxon signed-rank test. Statistical significance was accepted at a p value less than .05.RESULTS: ibration therapy, dynamic compliance and statics compliance demonstrated a significant increase immediately and remained increased until 30 minutes after chest physiotherapy. palm cum percussion therapy saturation showed a significant increase immediately chest physiotherapyut there were no significant differences in tidal volume, dynamic compliance and statics compliance.CONCLUSION: In this study, we analyzed the effects of oscillation method and palm cup percussion method separately for each type of chest physiotherapy. Nursing interventions that actively utilize vibration methods should be provided to patients with respiratory diseases.

Avaliação do tamanho do pulmão em cães: a capacidade inspiratória define o volume corrente / Sizing the lung in dogs: the inspiratory capacity defines the tidal volume

RESUMO Objetivo: Avaliar uma nova abordagem fisiológica para a determinação do volume corrente em ventilação mecânica, de acordo com a capacidade inspiratória, e determinar se isso resulta em medidas mecânicas e de troca gasosa adequadas em cães saudáveis e em estado crítico. Métodos: Incluíram-se, neste estudo, 24 animais para avaliar o volume corrente expresso como porcentagem da capacidade inspiratória. Para mensuração da capacidade inspiratória, o ventilador mecânico foi regulado como segue: modo controle de pressão, com 35cmH2O de pressão de inspiração e pressão expiratória final de zero, por 5 segundos. Subsequentemente, estudaram-se dez cães em condições clínicas críticas. Resultados: Cães saudáveis ventilados com volume corrente que correspondia a 17% da capacidade inspiratória demonstraram mecânica respiratória normal e apresentaram os valores previstos de PaCO2 mais frequentemente do que os animais nos demais grupos. A pressão no sistema respiratório e a pressão transpulmonar foram significantemente mais elevadas nos cães em condição crítica, porém em todos os casos, estiveram abaixo de 15cmH2O. Conclusões: O volume corrente calculado com base na capacidade inspiratória de cada animal comprovou ser uma ferramenta útil e simples para o estabelecimento dos parâmetros do ventilador. Convém também realizar abordagem semelhante em outras espécies, inclusive no ser humano, quando se consideram as potenciais limitações da titulação do volume corrente, com base no peso corpóreo ideal calculado.

ABSTRACT Objective: To evaluate a novel physiological approach for setting the tidal volume in mechanical ventilation according to inspiratory capacity, and to determine if it results in an appropriate mechanical and gas exchange measurements in healthy and critically ill dogs. Methods: Twenty healthy animals were included in the study to assess the tidal volume expressed as a percentage of inspiratory capacity. For inspiratory capacity measurement, the mechanical ventilator was set as follows: pressure control mode with 35cmH2O of inspired pressure and zero end-expiratory pressure for 5 seconds. Subsequently, the animals were randomized into four groups and ventilated with a tidal volume corresponding to the different percentages of inspiratory capacity. Subsequently, ten critically ill dogs were studied. Results: Healthy dogs ventilated with a tidal volume of 17% of the inspiratory capacity showed normal respiratory mechanics and presented expected PaCO2 values more frequently than the other groups. The respiratory system and transpulmonary driving pressure were significantly higher among the critically ill dogs but below 15 cmH2O in all cases. Conclusions: The tidal volume based on the inspiratory capacity of each animal has proven to be a useful and simple tool when setting ventilator parameters. A similar approach should also be evaluated in other species, including human beings, if we consider the potential limitations of tidal volume titration based on the calculated ideal body weight.

Efficacy of preoxygenation using tidal volume breathing: a comparison of Mapleson A, Bain's and Circle system / Eficácia da pré-oxigenação usando respiração em volume corrente: uma comparação dos sistemas Mapleson A, Bain e Circular

Abstract Background: Efficacy of preoxygenation depends upon inspired oxygen concentration, its flow rate, breathing system configuration and patient characteristics. We hypothesized that in actual clinical scenario, where breathing circuit is not primed with 100% oxygen, patients may need more time to achieve EtO2 ≥ 90%, and this duration may be different among various breathing systems. We thus studied the efficacy of preoxygenation using unprimed Mapleson A, Bain's and Circle system with tidal volume breathing at oxygen flow rates of 5 L.min−1 and 10 L.min−1. Methods: Patients were randomly allocated into one of the six groups, wherein they were preoxygenated using either Mapleson A, Bain's or Circle system at O2 flow rate of either 5 L.min−1 or 10 L.min−1. The primary outcome measure of our study was the time taken to achieve EtO2 ≥ 90% at 5 and 10 L.min−1 flow rates. Results: At oxygen flow rate of 5 L.min−1, time to reach EtO2 ≥ 90% was significantly longer with Bain's system (3.7 ± 0.67 min) than Mapleson A and Circle system (2.9 ± 0.6, 3.3 ± 0.97 min, respectively). However at oxygen flow rate of 10 L.min−1 this time was significantly shorter and comparable among all the three breathing systems (2.33 ± 0.38 min with Mapleson, 2.59 ± 0.50 min with Bain's and 2.60 ± 0.47 min with Circle system). Conclusions: With spontaneous normal tidal volume breathing at oxygen flow rate of 5 L.min−1, Mapleson A can optimally preoxygenate patients within 3 min while Bain's and Circle system require more time. However at O2 flow rate of 10 L.min−1 all the three breathing systems are capable of optimally preoxygenating the patients in less than 3 min.

Resumo Justificativa: A eficácia da pré-oxigenação depende da concentração inspirada de oxigênio, do fluxo de gases, da configuração do circuito respiratório e das características do paciente. Nossa hipótese foi que, no cenário clínico real, no qual o circuito respiratório não é preparado com 100% de oxigênio, os pacientes podem precisar de mais tempo para atingir EtO2 ≥ 90% e essa duração pode ser diferente entre vários circuitos de respiração. Avaliamos, portanto, a eficácia da pré-oxigenação com o uso dos circuitos não preparados Mapleson A, Bain e Circular com volume corrente de respiração com um fluxo de oxigênio de 5 L.min−1 e 10 L.min−1. Métodos: Os pacientes foram alocados aleatoriamente em um dos seis grupos, nos quais foram pré-oxigenados com o uso do circuito Mapleson A, Bain ou Circular com um fluxo de O2 de 5 L.min−1 ou 10 L.min−1. O desfecho primário de nosso estudo foi o tempo necessário para atingir EtO2 ≥ 90% com um fluxo de 5 e 10 L.min−1. Resultados: Com um fluxo de oxigênio de 5 L.min−1, o tempo para atingir EtO2 ≥ 90% foi significativamente maior com o circuito Bain (3,7 ± 0,67 min) do que com os circuitos Mapleson A e Circular (2,9 ± 0,6 e 3,3 ± 0,97 min, respectivamente). No entanto, com o fluxo de oxigênio de 10 L.min−1 foi significativamente menor e comparável entre os três circuitos respiratórios (2,33 ± 0,38 min com Mapleson; 2,59 ± 0,50 min com Bain e 2,60 ± 0,47 min com o Circular). Conclusões: Durante respiração espontânea com volume corrente normal e com um fluxo de oxigênio de 5 L.min−1, o sistema Mapleson A pode pré-oxigenar o paciente de forma ideal dentro de três minutos, enquanto os sistemas Bain e Circular requerem mais tempo. Porém, com um fluxo de O2 de 10 L.min−1, todos os três circuitos respiratórios podem pré-oxigenar o paciente de forma ideal em menos de três minutos.

Effective Tidal Volume for Normocapnia in Very-Low-Birth-Weight Infants Using High-Frequency Oscillatory Ventilation

PURPOSE: Removal of CO₂ is much efficient during high-frequency oscillatory ventilation (HFOV) for preterm infants. However, an optimal carbon dioxide diffusion coefficient (DCO₂) and tidal volume (VT) have not yet been established due to much individual variance. This study aimed to analyze DCO₂ values, VT, and minute volume in very-low-birth-weight (VLBW) infants using HFOV and correlates with plasma CO₂ (pCO₂). MATERIALS AND METHODS: Daily respiratory mechanics and ventilator settings from twenty VLBW infants and their two hundred seventeen results of blood gas analysis were collected. Patients were treated with the Dräger Babylog VN500 ventilator (Drägerwerk Ag & Co.) in HFOV mode. The normocapnia was indicated as pCO₂ ranging from 45 mm Hg to 55 mm Hg. RESULTS: The measured VT was 1.7 mL/kg, minute volume was 0.7 mL/kg, and DCO₂ was 43.5 mL²/s. Mean results of the blood gas test were as follows: pH, 7.31; pCO₂, 52.6 mm Hg; and SpO₂, 90.5%. In normocapnic state, the mean VT was significantly higher than in hypercapnic state (2.1±0.5 mL/kg vs. 1.6±0.3 mL/kg), and the mean DCO₂ showed significant difference (68.4±32.7 mL²/s vs. 32.4±15.7 mL²/s). The DCO₂ was significantly correlated with the pCO₂ (p=0.024). In the receiver operating curve analysis, the estimated optimal cut-off point to predict the remaining normocapnic status was a VT of 1.75 mL/kg (sensitivity 73%, specificity 80%). CONCLUSION: In VLBW infants treated with HFOV, VT of 1.75 mL/kg is recommended for maintaining proper ventilation.

Application of protective lung ventilation model in thoracic surgery patients with single lung ventilation / 中国医师杂志

Objective To explore the value of protective lung ventilation mode in patients undergoing single lung ventilation in thoracic surgery operation.Methods 59 patients undergoing surgical treatment in Ankang Central Hospital from January 2012 to January 2015 were analyzed.According to the ventilation mode adopted in the operation,the patients were divided into the protective group (30 cases) and conventional group (29 cases).The protective group took tidal volume 8 ml/kg.According to the patient's circulatory function,we gradually increase the end expiratory positive pressure ventilation,until 10 cmH2O.The conventional group took tidal volume 8 ml/kg and was maintained positive end expiratory pressure at 3 cmH2O.Results There was no statistically significant difference in operation time,blood volume,infusion volume,and single lung ventilation time between the protective group and the conventional group (P ＞ 0.05).There was also no statistically significant difference in T1,T2,T3,T4,inhalation of oxygen partial pressure (FiO2),mean arterial pressure (MAP) level between the two groups (P ＞ 0.05).The T2 and T3 moment of arterial oxygen partial pressure (PaO2) oxygenation index (OI) level in protective group was significantly higher than that in conventional group (P ＜ 0.05).The preoperative serum tumor necrosis factor-α (TNF-α),interleukin-8 (IL-8),superoxide dismutase (SOD),macrophage inflammatory protein Ⅰ (MIP-Ⅰ),malondialdehyde (MDA) level between the two group showed no significant difference (P ＞0.05).While after the operation,the serum TNF-alpha,MIP-Ⅰ,IL-8 and the level of MDA in protective group was significantly lower than that of conventional group (P ＜ 0.05),the SOD level showed the opposite (P ＜ 0.05).Conclusions The protective lung ventilation mode is beneficial to maintain the blood gas indexes,at the same time reduce the inflammatory response and protect the lung function of the patients.

Application of low tidal volume, apnea ventilation and low PEEP in soft ureteroscope surgery / 中国内镜杂志

Objective To research the application of low tidal volume, apnea ventilation and low PEEP in soft ureteroscope surgery. Methods 80 patients with renal calculi who underwent ureteroscopic holmium laser lithotripsy were randomly divided into tow groups, 40 patients in each group. The observation group was treated with low tidal volume, apnea ventilation and Low PEEP, and the control group was treated with low tidal volume and apnea ventilation. Recorded the HR, MBP, PaCO2, PaO2, Ppeak, A-aDO2, and recorded A-aDO2at pre-anesthesia, preoperation, tracheal extubation, 30 min after tracheal extubation and 24 hours after surgery in tow groups. And observed the trend of RI and CLdyn in tow groups. Results There were no satistically significant differences of HR, MBP, Ppeak and Pmean after recovery and that before apnea in the observation group (P > 0.05); the HR, MBP, Ppeak and Pmean of the observation group was lower than that of the control group after recovery (P < 0.05); the PaO2 of the observation group was higher than that of the control group after recovery (P < 0.05); at tracheal extubation, 30min after tracheal extubation and 24 hours after surgery, the A-aDO2 of the observation group was lower than thatof the control group (P < 0.05); the CLdyn 20 in the observation group was better than that in the control group(P < 0.05). Conclusion In soft ureteroscope surgery, the application of Low tidal volume, apnea ventilation andlow PEEP can ensure the asfe of operation, and maintain the vital aspect, results of blood gas analysis smoothly; andprotect the lung function, promote the recovery of the patients.

The characteristics of respiratory parameters in patients with different body mass index during general anesthesia with tracheal intubation / 实用医学杂志

Objective To explore the characteristics of respiratory parameters in patients with different body mass index during general anesthesia with tracheal intubation. Methods 102 patients scheduled for otitis me-dia surgery were divided into low weight group(B1,n=32),normal weight group(B2,n=36)and overweight or obese group(B3,n = 34 ). After general anesthesia with tracheal intubation,the tidal volume of anesthetic ma-chine wasadjusted to maintain the end tidal carbon dioxide partial pressure between 35 - 45 mmHg. At 10 min (T1),30min(T2)and 60 min(T3)after adjustment,arterial PH,arterial partial pressure of oxygen(PaO2),arte-rial carbon dioxide pressure(PaCO2),inspiratory tidal volume(VTi),expiratory tidal volume(VTe),end tidal carbon dioxide partial pressure(PETCO2),peak airway pressure(Ppeak),plateau airway pressure(Pplat)and dy-namic lung compliance(Cdyn)were recorded. Results PH and PaO2 were not significantly different at T1-3 among the three groups(P>0.05). As compared with group B1 and B2,PaCO2 was lower in group B3. In comparison with group B2,VTi,VTe and Cdyn were higher in group B1 and lower in group B3(P < 0.05). Ppeak and Pplat were lower in group B1 but higher in group B3(P<0.05). PETCO2 was higher in group B1(P>0.05)while lower in group B3 (P < 0.05). Conclusions With the increase in BMI during general anesthesia with tracheal intubation ,the VTi,VTe,Cdyn,PETCO2 and PaCO2 decrease significantly,but Ppeak and Pplat elevate markedly. BMI is a refer-ence index for setting respiratory parameters.

Asociación y valor predictivo del poder mecánico con los días libres de ventilación mecánica / Association and predictive value of mechanical power with ventilator-free days / Associação e valor preditivo do poder mecânico com os dias livres de ventilação mecânica

Resumen Introducción: La afección pulmonar atribuible a la ventilación mecánica (VM) ha sido denominada lesión pulmonar asociada con la ventilación mecánica (LPAVM). La fórmula del poder mecánico (PM) reúne las principales variables que determinan el desarrollo de la LPAVM. Analizamos la correlación entre el PM y los días libres de ventilación mecánica (DLVMI), así como la capacidad de predicción para DLVMI. Material y métodos: Se estudiaron 40 pacientes ingresados a la unidad de terapia intensiva (UTI) y que cumplieron con los criterios de inclusión. Se recabaron las variables demográficas, clínicas y de laboratorio. Se realizó el cálculo del poder mecánico en las primeras 24 horas de estancia en la UTI y se determinaron los DLVMI, estancia en la UTI y mortalidad en la UTI. Se realizó la prueba de rho de Spearman para determinar la correlación entre PM y DLVM; análisis multivariado de regresión binaria. Para evaluar la capacidad predictiva de las variables que se relacionaron de forma independiente, se compararon las áreas bajo la curva en la curva de características operativas del receptor (ROC). Resultados: PM y DLVM tienen correlación inversa de magnitud intermedia. Se asociaron de manera independiente: PM OR 2.07, IC 95% (1.10-4.09), p = 0.01, frecuencia respiratoria OR 1.5, IC 95% (1.05-2.3), p = 0.04 y Vt/kg (≤ 8.2 mL) un OR 0.01, IC 95% (0.001-0.10), p = 0.002. El área bajo la curva (ABC) fue PM (ABC) 0.75, IC 95% (0.59-0.90), p = 0.007, FR (ABC) 0.71, IC 95% (0.54-0.88), p = 0.01 y Vt/kg (ABC) 0.92, IC (0.83-1.0), p = 0.001. Conclusión: El poder mecánico se correlaciona de forma inversa con los días libres de ventilación mecánica, con adecuada capacidad predictiva para días libres de ventilación mecánica invasiva, con un punto de corte en 13 Joules/min.

Abstract Introduction: Pulmonary disease attributable to mechanical ventilation (MV) has been named ventilator-associated lung injury (VALI). The mechanical power formula (MP) brings together the main variables that determine VALI development. It analyzes the correlation between MP and ventilator-free days (VFD), as well as the predictive capacity for VFD. Material and methods: We studied 40 patients admitted to the intensive care unit (ICU) and who met the inclusion criteria. Demographic, clinical and laboratory data were collected. MP calculation was performed in the first 24 hours of ICU stay and we determined VFD, ICU stay and ICU mortality. The Spearman's rho test was performed to determine the correlation between MP and VFD; we performed the bi-varied and later multivariate binary regression analysis. To evaluate the predictive capacity of the variables that were independently related, we compared the areas under the curve (AUC) in the receiver operating characteristics (COR) curve. Results MP and VFD have an inverse correlation with intermediate magnitude. They were independently associated: MP OR 2.07, 95% CI (1.10-4.09), p = 0.01, respiratory rate OR 1.5, 95% CI (1.05-2.3), p = 0.04 and Tv/ kg (≤ 8.2 mL) OR 0.01, 95% CI (0.001-0.10), p = 0.002. MP (AUC) 0.75, 95% CI (0.59-0.90), p = 0.007, respiratory rate (ABC) 0.71, 95% CI (0.54-0.88), p = 0.01 and Tv/kg (ABC) 0.92, IC (0.83-1.0), p = 0.001. Conclusion: MP and VFD have inverse correlation, with ability for predicting VFD, with a cutoff point of 13 Joules/min.

Resumo Introdução A alteração pulmonar induzida pela ventilação mecânica (VM) definiu-se como lesão pulmonar associada à ventilação (LPAV). A fórmula do poder mecânico (PM) reúne as principais variáveis que determinam o desenvolvimento da LPAV. Analisamos à correlação entre PM e os dias livres de ventilação mecânica (DLVM), assim como a capacidade de previsão para DLVM. Métodos Estudamos 40 pacientes internados na unidade de terapia intensiva (UTI) e que completaram os critérios de inclusão. Foram coletados dados demográficos, clínicos e laboratoriais. O cálculo do PM foi realizado nas primeiras 24 horas da internação na UTI e determinamos DLVM, permanência e mortalidade na UTI. O teste de rho Spearman foi realizado para determinar a correlação entre PM e DLVM; análise multivariada de regressão binária. Para avaliar a capacidade preditiva das variáveis que se relacionaram de maneira independente, comparamos as áreas sob a curva na curva de características operativas do receptor (COR). Resultados PM e DLVM têm correlação inversa de magnitude intermediária. Se associaram de maneira independente: PM OR 2.07, IC 95% (1.10-4.09), p = 0.01, frequência respiratória OR 1.5, IC 95% (1.05-2.3), p = 0.04 e Vt/kg (< 8.2 mL) um OR 0.01, IC 95% (0.001-0.10), p = 0.002. Na área sob a curva (ABC) foi PM (ABC) 0.75, IC 95% (0.59-0.90), p = 0.007, FR (ABC) 0.71, IC 95% (0.54-0.88), p = 0.01 e Vt/kg (ABC) 0.92, IC (0.83-1.0), p = 0.001. Conclusões O poder mecânico têm correlação inversa com os dias livres de ventilação mecânica, com adequada capacidade preditiva para os dias livres de ventilação mecânica invasiva, com um ponto de corte de 13 Joules/min.