Clinical evaluation of ventilation mode on acute exacerbation of chronic obstructive pulmonary disease with respiratory failure

BACKGROUND At present,understanding of the most effective ventilation methods for treating chronic obstructive pulmonary disease(COPD)patients experiencing acute worsening symptoms and respiratory failure remains relatively limited.This report analyzed the efficiency and side effects of various ventilation techniques used for individuals experiencing an acute COPD exacerbation.AIM To determine whether pressure-controlled ventilation(PCV)can lower peak airway pressures(PAPs)and reduce the incidence of barotrauma compared to volume-controlled ventilation(VCV),without compromising clinical outcomes and oxygenation parameters.METHODS We have evaluated 600 patients who were hospitalized due to a severe COPD exacerbation,with 400 receiving mechanical ventilation for the respiratory failure.The participants were divided into two different groups,who were administered either VCV or PCV,along with appropriate management.We thereafter observed patients'attributes,clinical factors,and laboratory,radiographic,and arterial blood gas evaluations at the start and during their stay in the intensive care unit(ICU).We have also employed appropriate statistical methods for the data analysis.RESULTS Both the VCV and PCV groups experienced significant enhancements in the respiratory rate,tidal volume,and arterial blood gas values during their time in the ICU.However,no significant distinctions were detected between the groups in terms of oxygenation indices(partial pressures of oxygen/raction of inspired oxygen ratio)and partial pressures of carbon dioxide improvements.There was no considerable disparity observed between the VCV and PCV groups in the hospital mortality(32%vs 28%,P=0.53),the number of days of ICU stay[median interquartile range(IQR):9(6-14)d vs 8(5-13)d,P=0.41],or the duration of the mechanical ventilation[median(IQR):6(4-10)d vs 5(3-9)d,P=0.47].The PCV group displayed lower PAPs compared to the VCV group(P<0.05)from the beginning of mechanical ventilation until extubation or ICU departure.The occurrence of barotrauma was considerably lower in the PCV group in comparison to the VCV group(6%vs 16%,P=0.03).CONCLUSION Both VCV and PCV were found to be effective in treating patients with acute COPD exacerbation.However,PCV was associated with lower PAPs and a significant decrease in barotrauma,thus indicating that it might be a safer ventilation method for this group of patients.However,further large-scale study is necessary to confirm these findings and to identify the best ventilation approach for patients experiencing an acute COPD exacerbation.

Clinical Analysis of Early Noninvasive Mechanical Ventilation in the Treatment of Acute Left Heart Failure Complicated with Respiratory Failure

Objective To evaluate the efficacy of early and non-early non-invasive mechanical ventilation(NIV) for acute left heart failure and respiratory failure. Methods 29 cases of patients with acute left heart failure and respiratory failure treated by NIV were selected from our department from August 2016 to March 2019. According to the time of initiation of noninvasive mechanical ventilation, the patients were divided into the early treatment group(group A, treatment with NIV immediately after admission, n=15) and the non-early treatment group(group B, treatment with NIV for 2 h after admission, n=14), the improvement time, mechanical ventilation time, effective rate, intubation rate and fatality rate were compared between the two groups. Results The improvement time of patients in group A was(4.8±2.5) hours, the time of mechanical ventilation was(9.6±3.2) hours, the improvement time of group B was(6.8±2.6) hours, and the time of mechanical ventilation(12.8±4.4) hours. There were significant differences between the two groups(P<0.05). In group A, 13 patients were cured, 2 patients were intubated, 1 patient died, 10 patients in group B were cured, 4 patients were intubated, and 2 patients died. The difference in cure rate, intubation rate and mortality was statistically significant(P<0.05). Conclusion The treatment of acute left heart failure and respiratory failure is effective, and early application can improve the cure rate, reduce intubation and mortality.

Driving pressure in mechanical ventilation:A review

Driving pressure(ΔP)is a core therapeutic component of mechanical ventilation(MV).Varying levels ofΔP have been employed during MV depending on the type of underlying pathology and severity of injury.However,ΔP levels have also been shown to closely impact hard endpoints such as mortality.Considering this,conducting an in-depth review ofΔP as a unique,outcome-impacting therapeutic modality is extremely important.There is a need to understand the subtleties involved in making sureΔP levels are optimized to enhance outcomes and minimize harm.We performed this narrative review to further explore the various uses ofΔP,the different parameters that can affect its use,and how outcomes vary in different patient populations at different pressure levels.To better utilizeΔP in MV-requiring patients,additional large-scale clinical studies are needed.

Effect of different ventilation methods combined with pulmonary surfactant on neonatal acute respiratory distress syndrome

BACKGROUND Acute respiratory distress syndrome precipitates is widespread pulmonary injury in impacted individuals,the neonatal respiratory distress syndrome(NRDS),primarily observed in preterm infants,represents a prevalent critical condition in neonatal clinical settings.AIM To investigate the clinical efficacy of various ventilation strategies combined with pulmonary surfactant(PS)therapy in the treatment of NRDS.METHODS A total of 20 neonates diagnosed with respiratory distress syndrome,admitted between May 2021 and June 2022,were randomly assigned to either a research group or a control group.Neonates in the research group received treatment involving high-frequency oscillatory ventilation(HFOV)in conjunction with PS.In contrast,neonates in the control group were administered either controlled mechanical ventilation or synchronous intermittent mandatory ventilation,combined with PS.Arterial blood samples from the neonates in both groups were collected before treatment,as well as 6 h,12 h,24 h,and 48 h post-treatment.These samples underwent blood gas analysis,with measurements taken for pH value,partial pressures of oxygen(O_(2))and carbon dioxide.Concurrently,data was collected on the duration of ventilator use,length of hospitalization time,O_(2) treatment time,treatment outcomes,and complications of the ventilator.RESULTS From 6-48 h post-treatment,both groups demonstrated significant improvements in arterial blood pH and oxygen partial pressure,along with a significant decrease in carbon dioxide partial pressure compared to pre-treatment values(P<0.05).Although these changes progressed over time,there were no significant differences between the two groups(P>0.05).However,the research group had significantly lower X-ray scores,shorter hospitalization time,and less time on O_(2) therapy compared to the control group(P<0.05).Mortality rates were similar between the two groups(P>0.05),but the research group had a significantly lower incidence of complications(P<0.05).CONCLUSION The integration of HFOV combine with PS has proven to effectively expedite the treatment duration,decrease the occurrence of complications,and secure the therapeutic efficacy in managing NRDS.

Clinical characteristics and outcomes associated with nasal intermittent mandatory ventilation in acute pediatric respiratory failure

AIM To characterize the clinical course and outcomes of nasal intermittent mandatory ventilation(NIMV) use in acute pediatric respiratory failure.METHODS We identified all patients treated with NIMV in the pediatric intensive care unit(PICU) or inpatient general pediatrics between January 2013 and December 2015 at two academic centers.Patients who utilized NIMV with other modes of noninvasive ventilation during the same admission were included.Data included demographics,vital signs on admission and prior to initiation of NIMV,pediatric risk of mortality Ⅲ(PRIsM-Ⅲ) scores,complications,respiratory support characteristics,PICU and hospital length of stays,duration of respiratory support,and complications.Patients who did not require escalation to mechanical ventilation were defined as NIMV responders;those who required escalation to mechanical ventilation(MV) were defined as NIMV nonresponders.NIMV responders were compared to NIMV non-responders.RESULTS Forty-two patients met study criteria.six(14%) failed treatment and required MV.The majority of the patients(74%) had a primary diagnosis of bronchiolitis.The median age of these 42 patients was 4 mo(range 0.5-28.1 mo,IQR 7,P = 0.69).No significant difference was measured in other baseline demographics and vitals on initiation of NIMV;these included age,temperature,respiratory rate,O2 saturation,heart rate,systolic blood pressure,diastolic blood pressure,and PRIsM-Ⅲ scores.The duration of NIMV was shorter in the NIMV nonresponder vs NIMV responder group(6.5 h vs 65 h,P < 0.0005).Otherwise,NIMV failure was not associated with significant differences in PICU length of stay(LOs),hospital LOs,or total duration of respiratory support.No patients had aspiration pneumonia,pneumothorax,or skin breakdown.CONCLUSION Most of our patients responded to NIMV.NIMV failure is not associated with differences in hospital LOs,PICU LOs,or duration of respiratory support.

Reducing acute respiratory distress syndrome occurrence using mechanical ventilation

The standard treatment for acute respiratory distress syndrome(ARDS) is supportive in the form of low tidal volume ventilation applied after significant lung injury has already developed. Nevertheless, ARDS mortality remains unacceptably high(> 40%). Indeed, once ARDS is established it becomes refractory to treatment, and therefore avoidance is key. However, preventive techniques and therapeutics to reduce the incidence of ARDS in patients at high-risk have not been validated clinically. This review discusses the current data suggesting that preemptive application of the properly adjusted mechanical breath can block progressive acute lung injury and significantly reduce the occurrence of ARDS.

A Patient with End-stage Respiratory Failure Gets Recovery from Mechanical Ventilation by Utilization of Chinese Traditional Medicine

Ventilator-assisted ventilation and lung transplantation are the final treatments for the patients with end-stage respiratory failure.A patient,who has been diagnosed as end-stage respiratory failure and received tracheal intubation with mechanical ventilation,received the treatment of Chinese herbal medicine on the principle of TCM and got some recovery gradually.After two months,the patient got rid of mechanical ventilation successfully.This case implies that TCM will be an alternative treatment for the patients with the similar conditions.

Sequential treatment of severe pneumonia with respiratory failure and its influence on respiratory mechanical parameters and hemodynamics

BACKGROUND The pathophysiological characteristics of severe pneumonia complicated by respiratory failure comprise pulmonary parenchymal changes leading to ventilation imbalance,alveolar capillary injury,pulmonary edema,refractory hypoxemia,and reduced lung compliance.Prolonged hypoxia can cause acid-base balance disorder,peripheral circulatory failure,blood-pressure reduction,arrhythmia,and other adverse consequences.AIM To investigate sequential mechanical ventilation’s effect on severe pneumonia complicated by respiratory failure.METHODS We selected 108 patients with severe pneumonia complicated by respiratory failure who underwent mechanical ventilation between January 2018 and September 2020 at the Luhe Hospital’s Intensive Care Unit and divided them into sequential and regular groups according to a randomized trial,with each group comprising 54 patients.The sequential group received invasive and non-invasive sequential mechanical ventilation,whereas the regular group received invasive mechanical ventilation.Blood-gas parameters,hemodynamic parameters,respiratory mechanical parameters,inflammatory factors,and treatment outcomes were compared between the two groups before and after mechanical-ventilation treatment.RESULTS The arterial oxygen partial pressure and stroke volume variation values of the sequential group at 24,48,and 72 h of treatment were higher than those of the conventional group(P<0.05).The carbon dioxide partial pressure value of the sequential group at 72 h of treatment and the Raw value of the treatment group at 24 and 48 h were lower than those of the conventional group(P<0.05).The pH value of the sequential group at 24 and 72 h of treatment,the central venous pressure value of the treatment at 24 h,and the Cst value of the treatment at 24 and 48 h were higher than those of the conventional group(P<0.05).The tidal volume in the sequential group at 24 h of treatment was higher than that in the conventional group(P<0.05),the measured values of interleukin-6 and tumor necrosis factor-αin the sequential group at 72 h of treatment were lower than those in the conventional group(P<0.05),and the total time of mechanical ventilation in the sequential group was shorter than that in the conventional group,with a statistically significant difference(P<0.05).CONCLUSION Treating severe pneumonia complicated by respiratory failure with sequential mechanical ventilation is more effective in improving respiratory system compliance,reducing inflammatory response,maintaining hemodynamic stability,and improving patient blood-gas levels;however,from this study’s perspective,it cannot reduce patient mortality.

Preemptive mechanical ventilation can block progressive acute lung injury

Mortality from acute respiratory distress syndrome(ARDS) remains unacceptable, approaching 45% in certain high-risk patient populations. Treating fulminant ARDS is currently relegated to supportive care measures only. Thus, the best treatment for ARDS may lie with preventing this syndrome from ever occurring. Clinical studies were examined to determine why ARDS has remained resistant to treatment over the past several decades. In addition, both basic science and clinical studies were examined to determine the impact that early, protective mechanical ventilation may have on preventing the development of ARDS in at-risk patients. Fulminant ARDS is highly resistant to both pharmacologic treatment and methods of mechanical ventilation. However, ARDS is a progressive disease with an early treatment window that can be exploited. In particular, protective mechanical ventilation initiated before the onset of lung injury can prevent the progression to ARDS. Airway pressure release ventilation(APRV) is a novel mechanical ventilation strategy for delivering a protective breath that has been shown to block progressive acute lung injury(ALI) and prevent ALI from progressing to ARDS. ARDS mortality currently remains as high as 45% in some studies. As ARDS is a progressive disease, the key to treatment lies with preventing the disease from ever occurring while it remains subclinical. Early protective mechanical ventilation with APRV appears to offer substantial benefit in this regard and may be the prophylactic treatment of choice for preventing ARDS.

Application of fiberoptic bronchscopy in patients with acute exacerbations of chronic obstructive pulmonary disease during sequential weaning of invasive-noninvasive mechanical ventilation

BACKGROUND:Early withdrawal of invasive mechanical ventilation(IMV) followed by noninvasive MV(NIMV) is a new strategy for changing modes of treatment in patients with acute exacerbations of chronic obstructive pulmonary disease(AECOPD) with acute respiratory failure(ARF).Using pulmonary infection control window(PIC window) as the switch point for transferring from invasive to noninvasive MV,the time for early extubation can be more accurately judged,and therapy efficacy can be improved.This study aimed to prospectively investigate the clinical effectiveness of fiberoptic bronchscopy(FOB) in patients with AECOPD during sequential weaning of invasive-noninvasive MV.METHODS:Since July 2006 to January 2011,106 AECOPD patients with ARF were treated with comprehensive medication and IMV after hospitalization.Patients were randomly divided into two groups according to whether fiberoptic bronchoscope is used(group A,n=54) or not(group B,n=52) during sequential weaning from invasive to noninvasive MV.In group A,for sputum suction and bronchoalveolar lavage(BAL),a fiberoptic bronchoscope was put into the airway from the outside of an endotracheal tube,which was accompanied with uninterrupted use of a ventilator.After achieving PIC window,patients of both groups changed to NIMV mode,and weaned from ventilation.The following listed indices were used to compare between the groups after treatment:1) the occurrence time of PIC,the duration of MV,the length of ICU stay,the success rate of weaning from MV for the first time,the rate of reventilatJon and the occurrence rate of ventilator-associated pneumonia(VAP);2) the convenience and safety of FOB manipulation.The results were compared using Student's f test and the Chi-square test.RESULTS:The occurrence time of PIC was(5.01 ±1.49) d,(5.87±1.87) d in groups A and B,respectively(P<0.05);the duration of MV was(6.98±1.84) d,(8.69±2.41) d in groups A and B,respectively(P<0.01);the length of ICU stay was(9.25±1.84) d,(11.10±2.63) d in groups A and B,respectively(P<0.01);the success rate of weaning for the first time was 96.30%,76.92%in groups A and B,respectively(P<0.01);the rate of reventilation was 5.56%,19.23%in groups A and B,respectively(P<0.05);and the occurrence rate of VAP was 3.70%,23.07%in groups A and B,respectively(P<0.01).Moreover,it was easy and safe to manipulate FOB,and no side effect was observed.CONCLUSIONS:The application of FOB in patients with AECOPD during sequential weaning of invasive-noninvasive MV is effective in ICU.It can decrease the duration of MV and the length of ICU stay,increase the success rate from weaning MV for the first time,reduce the rate of reventilation and the occurrence rate of VAP.In addition,such a method is convenient and safe in patients of this kind.

Effect of protective lung ventilation strategy combined with lung recruitment maneuver in patients with acute respiratory distress syndrome (ARDS)

Objective:To evaluate the efficacy and safety of protective lung ventilation strategy combined with lung recruitment maneuver (RM) in the treatment patients with acute respiratory distress syndrome (ARDS).Methods:Totally 74 patients with ARDS admitted to the Department of Intensive Care Unit, Changshu Second People's Hospital in Jiangsu Province between September 2010 and June 2013 were selected and randomly divided into lung recruitment group and non-lung recruitment group, and the initial ventilation solution for both groups was synchronized intermittent mandatory ventilation (SIMV). For RM, SIMV mode (pressure control and pressure support) was adopted. Positive end expiratory pressure (PEEP) was increased by 5 cm H2O every time and maintained for 40-50 s before entering the next increasing period, and the peak airway pressure was kept below 45 cm H2O. After PEEP reached the maximum value, it was gradually reduced by 5 cm H2O every time and finally maintained at 15 cm H2O for 10 min.Results:A total of 74 patients with mean age of (49.0±18.6) years old were enrolled, 36 patients were enrolled in lung recruitment maneuver (RM) group and 38 patients were enrolled into non-lung recruitment maneuver (non-RM) group. 44 were male and accounted for 59.5% of all the patients. For the indicators such as PEEP, pressure support (PS), plateau airway pressure (Pplat), peak airway pressure (Ppeak), vital capacity (VC) and fraction of inspired oxygen (FiO2), no statistical differences in the indicators were found between the RM group and non-RM group on D1, D3 and D7 (P>0.05), except that only FiO2 of RM group on D7 was significantly lower than that of non-RM group (47.2±10.0) vs. (52.2±10.5),P<0.05]. For the indicators of blood gas analysis, including pH, arterial oxygen pressure (PaO2), arterial carbon dioxide pressure (PaCO2) and oxygenation index (PaO2/FiO2), PaO2 and PaO2/FiO2 of RM group were significantly higher than those of non-RM group on D7, and the values were [(90.2±16.1) mmHg vs. (76.4±11.3) mmHg,P<0.05] and [(196.5±40.7) mmHg vs. (151.7±37.3) mmHg,P<0.05] respectively. There was no statistical difference in heart rate (HR), cardiac index (CI), central venous pressure (CVP) or mean arterial pressure (MAP) between RM group and non-RM group on D1, D3 and D7 (P>0.05). 28-day mortality, ICU mortality and in-hospital mortality were 25% vs. 28.9%, 25% vs. 26.3% and 36.1% vs. 39.5% respectively between RM group and non-RM group (allP>0.05).Conclusion:Protective lung ventilation strategy combined with lung recruitment maneuver can improve the indicators such as PaO2, FiO2 and PaO2/FiO2 on D7, but failed to improve the final outcomes such as 28-day mortality, ICU mortality and in-hospital mortality.

Clinical evaluation of prone position ventilation in the treatment of acute respiratory distress syndrome induced by sepsis

BACKGROUND Acute respiratory distress syndrome(ARDS)is an acute,diffuse,inflammatory lung injury.Previous studies have shown prone position ventilation(PPV)to be associated with improvement in oxygenation.However,its role in patients with ARDS caused by sepsis remains unknown.AIM To analyze the clinical effects of PPV in patients with ARDS caused by sepsis.METHODS One hundred and two patients with ARDS were identified and divided into a control group(n=55)and a PPV treatment group(n=47).Outcomes included oxygenation index,lung compliance(Cst)and platform pressure(Pplat),which were compared between the two groups after ventilation.Other outcomes included heart rate(HR),mean arterial pressure(MAP),central venous pressure(CVP),left ventricular ejection fraction(LVEF),the length of mechanical ventilation time and intensive care unit(ICU)stay,and levels of C-reactive protein(CRP),procalcitonin(PCT),and interleukin-6(IL-6)after ventilation.Finally,mortality rate was also compared between the two groups.RESULTS On the first day after ventilation,the oxygenation index and Cst were higher and Pplat level was lower in the PPV group than in the conventional treatment group(P<0.05).There were no significant differences in oxygenation index,Cst,and Pplat levels between the two groups on the 2^(nd),4^(th),and 7^(th) day after ventilation(P>0.05).There were no significant differences in HR,MAP,CVP,LVEF,duration of mechanical ventilation and ICU stay,and the levels of CRP,PCT,and IL-6 between the two groups on the first day after ventilation(all P>0.05).The mortality rates on days 28 and 90 in the PPV and control groups were 12.77% and 29.09%,and 25.53% and 45.45%,respectively(P<0.05).CONCLUSION PPV may improve respiratory mechanics indices and may also have mortality benefit in patients with ARDS caused by sepsis.Finally,PPV was not shown to cause any adverse effects on hemodynamics and inflammation indices.

Application of non-invasive ventilator in the treatment of acute heart failure merged with respiratory failure in ICU

Objective:To observe the application effect of non-invasive ventilator in the treatment of acute heart failure merged with respiratory failure in ICU.Methods:A total of 80 patients with acute heart failure merged with respiratory failure who were admitted in ICU from January, 2015 to January, 2016 were included in the study and randomized into the observation group and the control group with 40 cases in each group. The patients in the two groups were given routine treatments after admission. On this basis, the patients in the observation group were given non-invasive ventilator. The patients in the control group were given continuous low flow oxygen inhalation. PaO2, pH, PaCO2, SaO2, and PaO2/FiO2 before and after treatment between the two groups were compared. The serum NT-pro BNP and cTnI levels before treatment, 24 h and 48 h after treatment in the two groups were compared.Results:The comparison of PaO2, pH, PaCO2, SaO2, and PaO2/FiO2 before treatment between the two groups was not statistically significant. PaO2, pH, SaO2, and PaO2/FiO2 after treatment in the two groups were significantly elevated, while PaCO2 was significantly reduced when compared with before treatment. PaO2, pH, SaO2, and PaO2/FiO2 after treatment in the observation group were significantly higher than those in the control group, while PaCO2 was significantly lower than that in the control group. The comparison of NT-pro BNP and cTnI levels before treatment between the two groups was not statistically significant. NT-pro BNP and cTnI levels 12 h and 24 h after treatment in the two groups were significantly elevated when compared with before treatment. NT-pro BNP and cTnI levels 12 h and 24 h after treatment in the observation group were significantly lower than those in the control group.Conclusions:Non-invasive ventilator in the treatment of acute heart failure merged with respiratory failure can effectively improve the ventilation function, reduce NT-pro BNP and cTnI levels, and is of great significance in enhancing the rescued effect.

Predictive performance of the variation rate of the driving pressure on the outcome of invasive mechanical ventilation in patients with acute respiratory distress syndrome

Purpose:To assess the value of the driving pressure variation rate(ΔP%)in predicting the outcome of weaning from invasive mechanical ventilation in patients with acute respiratory distress syndrome.Methods:In this case-control study,a total of 35 patients with moderate-severe acute respiratory distress syndrome were admitted to the intensive care unit between January 2022 and December 2022 and received invasive mechanical ventilation for at least 48 h were enrolled.Patients were divided into successful weaning group and failed weaning group depending on whether they could be removed from ventilator support within 14 days.Outcome measures including driving pressure,PaO2:FiO2,and positive end-expiratory pressure,etc.were assessed every 24 h from day 0 to day 14 until successful weaning was achieved.The measurement data of non-normal distribution were presented as median(Q1,Q3),and the differences between groups were compared by Wilcoxon rank sum test.And categorical data use the Chi-square test or Fisher's exact test to compare.The predictive value ofΔP%in predicting the outcome of weaning from the ventilator was analyzed using receiver operating characteristic curves.Results:Of the total 35 patients included in the study,17 were successful vs.18 failed in weaning from a ventilator after 14 days of mechanical ventilation.The cut-off values of the medianΔP%measured by Operator 1 vs.Operator 2 in the first 4 days were≥4.17%and 4.55%,respectively(p<0.001),with the area under curve of 0.804(sensitivity of 88.2%,specificity of 64.7%)and 0.770(sensitivity of 88.2%,specificity of 64.7%),respectively.There was a significant difference in mechanical ventilation duration between the successful weaning group and the failure weaning group(8(6,13)vs.12(7.5,17.3),p=0.043).The incidence of ventilator-associated pneumonia in the successful weaning group was significantly lower than in the failed weaning group(0.2‰vs.2.3‰,p=0.001).There was a significant difference noted between these 2 groups in the 28-day mortality(11.8%vs.66.7%,p=0.003).Conclusion:The medianΔP%in the first 4 days of mechanical ventilation showed good predictive performance in predicting the outcome of weaning from mechanical ventilation within 14 days.Further study is needed to confirm this finding.

Respiratory evaluation of patients requiring ventilator support due to acute respiratory failure

This review, based on relevant published evidence and the authors` clinical experience, presents how to evaluate a patient with acute respiratory failure requiring ventilatory support. This patient must be carefully evaluated by nurses, physiotherapists, respiratory care practitioners and physicians regarding the elucidation of the cause of the acute episode of respiratory failure by means of physical examination with the measurement of respiratory parameters and assessment of arterial blood gases analysis to make a correct respiratory diagnosis. After the initial evaluation, the patient must quickly receive adequate oxygen and ventilatory support that has to be carefully monitored until its discontinuation. When available, a noninvasive ventilation trial must be done in patients presenting desaturation during oxygen mask and or PaCO2 retention, especially in cases of cardiogenic pulmonary edema and severe exacerbation of chronic obstructive pulmonary disease. In cases of noninvasive ventilation trial-failure, endotracheal intubation and invasive protective mechanical ventilation must be promptly initiated. In severe ARDS patients, low tidal ventilation, higher PEEP levels, prone positioning and recruitment maneuvers with adequate PEEP titration should be used. Recently, new modes of ventilation should allow a better patient-ventilator interaction or synchrony permitting a sufficient unloading of respiratory muscles and increase patient comfort. Patients with chronic obstructive pulmonary disease may be considered for a trial for early extubation to noninvasive positive pressure ventilation in centers with extensive experience in noninvasive positive pressure ventilation.

Role of diaphragmatic ultrasound in patients with acute exacerbation of chronic obstructive pulmonary disease

Assessing diaphragm function status is vital for diagnosing and treating acute exacerbation of chronic obstructive pulmonary disease(AECOPD).Diaphrag-matic ultrasound has become increasingly important due to its non-invasive nature,absence of radiation exposure,widespread availability,prompt results,high accuracy,and repeatability at the bedside.The diaphragm is a crucial respiratory muscle.Decline or dysfunction of the diaphragm can lead to dyspnea and even respiratory failure in AECOPD patients.In this editorial,we comment on an article,retrospectively analyzed ninety-four acute exacerbations of chronic obstructive pulmonary disease patients who received mechanical ventilation from January 2022 to December 2023.The study found that the diaphragm thickening fraction,an index from diaphragm ultrasound,can better predict the outcome of non-invasive ventilation in patients with AECOPD.The value of non-invasive ventilation in treating respiratory failure caused by AECOPD has been widely acknowledged.Diaphragmatic dysfunction diagnosed with ultrasound is asso-ciated with prolonged mechanical ventilation and weaning times and higher mortality.

Prognostic value of time-varying dead space estimates in mechanically ventilated patients with acute respiratory distress syndrome

Background The dead space fraction(VD/VT)has proven to be a powerful predictor of higher mortality in acute respiratory distress syndrome(ARDS).However,its measurement relies on expired carbon dioxide,limiting its widespread application in clinical practice.Several estimates employing routine variables have been found to be reliable substitutes for direct measurement of VD/VT.In this study,we evaluated the prognostic value of these dead space estimates obtained in the first 7 days following the initiation of ventilation.Methods This retrospective observational study was conducted using data from the Chinese database in intensive care(CDIC).Eligible participants were adult ARDS patients receiving invasive mechanical ventilation while in the intensive care unit between 1st January 2014 and 31st March 2021.We collected data during the first 7 days of ventilation to calculate various dead space estimates,including ventilatory ratio(VR),corrected minute ventilation(V_(Ecorr)),VD/VT(Harris–Benedict),VD/VT(Siddiki estimate),and VD/VT(Penn State estimate)longitudinally.A time-dependent Cox model was used to handle these time-varying estimates.Results A total of 392 patients(median age 66[interquartile range:55–77]years,median SOFA score 9[interquartile range:7–12])were finally included in our analysis,among whom 132(33.7%)patients died within 28 days of admission.VR(hazard ratio[HR]=1.04 per 0.1 increase,95%confidence interval[CI]:1.01 to 1.06;P=0.013),V_(Ecorr)(HR=1.08 per 1 increase,95%CI:1.04 to 1.12;P<0.001),VD/VT(Harris–Benedict)(HR=1.25 per 0.1 increase,95%CI:1.06 to 1.47;P=0.006),and VD/VT(Penn State estimate)(HR=1.22 per 0.1 increase,95%CI:1.04 to 1.44;P=0.017)remained significant after adjustment,while VD/VT(Siddiki estimate)(HR=1.10 per 0.1 increase,95%CI:1.00 to 1.20;P=0.058)did not.Given a large number of negative values,VD/VT(Siddiki estimate)and VD/VT(Penn State estimate)were not recommended as reliable substitutes.Long-term exposure to VR>1.3,V_(Ecorr)>7.53,and VD/VT(Harris–Benedict)>0.59 was independently associated with an increased risk of mortality in ARDS patients.These findings were validated in the fluid and catheter treatment trial(FACTT)database.Conclusions In cases where VD/VT cannot be measured directly,early time-varying estimates of VD/VT such as VR,,V_(Ecorr),and VD/VT(Harris–Benedict)can be considered for predicting mortality in ARDS patients,offering a rapid bedside application.

Efficacy of prone position in acute respiratory distress syndrome patients: A pathophysiology-based review

Acute respiratory distress syndrome(ARDS) is a syndrome with heterogeneous underlying pathological processes. It represents a common clinical problem in intensive care unit patients and it is characterized by high mortality. The mainstay of treatment for ARDS is lung protective ventilation with low tidal volumes and positive end-expiratory pressure sufficient for alveolar recruitment. Prone positioning is a supplementary strategy available in managing patients with ARDS. It was first described 40 years ago and it proves to be in alignment with two major ARDS pathophysiological lung models; the "sponge lung"- and the "shape matching"-model. Current evidence strongly supports that prone positioning has beneficial effects on gas exchange, respiratory mechanics, lung protection and hemodynamics as it redistributes transpulmonary pressure, stress and strain throughout the lung and unloads the right ventricle. The factors that individually influence the time course of alveolar recruitment and the improvement in oxygenation during prone positioning have not been well characterized. Although patients' response to prone positioning is quite variable and hard to predict, large randomized trials and recent meta-analyses show that prone position in conjunction with a lung-protective strategy, when performed early and in sufficient duration, may improve survival in patients with ARDS. This pathophysiology-based review and recent clinical evidence strongly support the use of prone positioning in the early management of severe ARDS systematically and not as a rescue maneuver or a last-ditch effort.

Ventilator management for acute respiratory distress syndrome associated with avian infl uenza A(H7N9) virus infection: A case series

BACKGROUND: Data on the mechanical ventilation(MV) characteristics and radiologic features for the cases with H7 N9-induced ARDS were still lacking.METHODS: We describe the MV characteristics and radiologic features of adult patients with ARDS due to microbiologically confirmed H7 N9 admitted to our ICU over a 3-month period.RESULTS: Eight patients(mean age 57.38±16.75; 5 male) were diagnosed with H7 N9 in the first quarter of 2014. All developed respiratory failure complicated by acute respiratory distress syndrome(ARDS), which required MV in ICU. The baseline APACHE II and SOFA score was 11.77±6.32 and 7.71±3.12. The overall CT scores of the patients was 247.68±34.28 and the range of CT scores was 196.3–294.7. The average MV days was 14.63±6.14, and 4 patients required additional rescue therapies for refractory hypoxemia. Despite these measures, 3 patients died.CONCLUSION: In H7 N9-infected patients with ARDS, low tidal volume strategy was the conventional mode. RM as one of rescue therapies to refractory hypoxemia in these patients with serious architectural distortion and high CT scores, which could cause further lung damage, may induce bad outcomes and requires serious consideration. Prone ventilation may improve mortality, and should be performed at the early stage of the disease, not as a rescue therapy.

Lung recruitment maneuver effects on respiratory mechanics and extravascular lung water index in patients with acute respiratory distress syndrome

BACKGROUND：Animal experiments showed that recruitment maneuver （RM） and protective ventilation strategy of the lung could improve oxygenation and reduce extravascular lung water. This study was to investigate the effects of RM on respiratory mechanics and extravascular lung water index （EVLWI） in patients with acute respiratory distress syndrome （ARDS）. METHODS：Thirty patients with ARDS were randomized into a RM group and a non-RM group. In the RM group, after basic mechanical ventilation stabilized for 30 minutes, RM was performed and repeated once every 12 hours for 3 days. In the non-RM group, lung protective strategy was conducted without RM. Oxygenation index （PaO2/FiO2）, peak inspiratory pressure （PIP）, Plateau pressure （Pplat）, static pulmonary compliance （Cst） and EVLWI of patients before treatment and at 12, 24, 48, 72 hours after the treatment were measured and compared between the groups. Hemodynamic changes were observed before and after RM. One-way ANOVA, Student＇s t test and Fisher＇s exact test were used to process the data. RESULTS：The levels of PaO2/FiO2 and Cst increased after treatment in the two groups, but they were higher in the RM group than in the non-RM group （P〈0.05）. The PIP and Pplat decreased after treatment in the two groups, but they were lower in the RM group than in the non-RM group （P〈0.05）. The EVLWI in the two groups showed downward trend after treatment （P〈0.05）, and the differences were signifcant at all time points （P〈0.01）; the EVLWI in the RM group was lower than that in the non-RM group at 12, 24, 48 and 72 hours （P〈0.05 or P〈0.01）. Compared with pre-RM, hemodynamics changes during RM were significantly different （P〈0.01）; compared with pre-RM, the changes were not significantly different at 120 seconds after the end of RM （P〉0.05）. CONCLUSIONS： RM could reduce EVLWI, increase oxygenation and lung compliance. The effect of RM on hemodynamics was transient.