Clinical prediction scores predicting weaning failure from invasive mechanical ventilation:Role and limitations

Invasive mechanical ventilation(IMV)has become integral to modern-day critical care.Even though critically ill patients frequently require IMV support,weaning from IMV remains an arduous task,with the reported weaning failure(WF)rates being as high as 50%.Optimizing the timing for weaning may aid in reducing time spent on the ventilator,associated adverse effects,patient discomfort,and medical care costs.Since weaning is a complex process and WF is often multifactorial,several weaning scores have been developed to predict WF and aid decision-making.These scores are based on the patient's physiological and ventilatory parameters,but each has limitations.This review highlights the current role and limitations of the various clinical prediction scores available to predict WF.

Invasive versus non-invasive ventilation in patients with COVID-19 pneumonia:A retrospective study

Objective:To compare the survival and length of stay of invasive ventilation(IV)with those of non-invasive ventilation(NIV)in patients with COVID-19 acute respiratory distress syndrome in a single hospital from May 2020 to March 2021.Methods:After obtaining approval from the Hospital Director,the data of COVID-19 patients including demographics,type of respiratory support(non-invasive ventilation or invasive ventilation),duration of ventilation,length of stay,discharge,and death were collected and analyzed.Results:Out of the 152 patients identified,134 patients were analyzed.The median intubation days were 10.0(Q1:3.5,Q3:13.5)in the IV group and 0.0(Q1:0.0,Q3:0.0)days in the NIV-only group.Out of the 101 patients who received NIV,43 patients were subsequently intubated due to failure of NIV.Of the 63 patients(47.01%)who died,22(66.66%)were from the IV group and 40(92.02%)were from the NIV-followed-by-intubation group,and 1(1.72%)were from the NIV-only group.Multivariate analysis showed that the presence of a respiratory comorbidity(OR=16.56,95%CI=1.56-175.48,P=0.02)was an independent predictor of survival.Conclusions:Respiratory co-morbidity is a significant adverse predictor of survival outcome.The decision on the type of respiratory support should be made on a patient-to-patient basis.

Non-Invasive Positive Pressure Ventilation (NIPPV) in the Pregnant Patient: A Case Series

Rationale: Acute respiratory failure is an uncommon complication of pregnancy. However, it is the most frequent organ dysfunction associated with obstetric admissions to an intensive care unit. The obstetric population is a different group due to its physiology and the presence of the fetus that lacks evidence in the literature within the subject of ventilatory support. Noninvasive positive pressure ventilation (NIPPV) is often avoided due to the lack of knowledge on the safety and efficacy of this modality. Currently, there are no guidelines for the management of respiratory failure in pregnancy. Objectives: To provide evidence in support of the use of NIPPV as a safe and reasonable modality for pregnant patients with respiratory failure. Methods: We retrospectively reviewed medical records of 29 pregnant patients of the Obstetric Critical Care Unit of a tertiary hospital in Panamá City who received NIPPV from 2013 to 2015. Failure to response was defined as the lack of increase in the paO2/FiO2 ratio or clinical deterioration 6 hours after initiating NIPPV. Demographics, indication for NIPPV, duration of treatment, as well as maternal and fetal outcomes were collected. Measurements and Main Results: Mean age was 28.4 ± 6 years, mean body mass index 27.4 ± 3.3, and mean gestational age at admission was 305/7 ± 5 weeks. Twenty-four patients (82.8%) met the criteria for acute lung injury (ALI) and an additional two (6.9%) for acute respiratory distress syndrome (ARDS). The mean duration of ventilation was 50.6 ± 17.27 hours. Statistically significant differences were noted between the paO2/FiO2 ratios in failure and successful patients within 2 hours of NIPPV therapy (P = 0.007) and paO2/FiO2 ratio within 6 hours of NIPPV therapy (P = 0.03). Success was defined when the patient was administered NIPPV, resulting in an improvement (increase in pa/FiO2 ratio) of her ventilatory parameters. Three patients (10.3%) failed to respond to NIPPV and needed to be converted to invasive mechanical ventilation. Patients who required intubation had a longer duration of ICU stay (P = 0.006) and overall hospital stay (P = 0.03). None of patients presented aspiration during NIPPV therapy. Conclusion: The current series is the largest report of pregnant patients requiring ventilatory support who received NIPPV as first line of therapy. This report shows the usefulness of this ventilation modality, avoiding intubation with its risks, of a significant number of patients, especially ventilator-associated pneumonia.

Cardiopulmonary Stability on a Patient with Hip Fracture and Severe Pulmonary Hypertension, Anesthetized with Lumbar-Sacral Plexus Block and Non-Invasive Ventilation: Case Report

Background: Pulmonary hypertension is defined as a mean arterial pressure in the pulmonary artery exceeding 20 mm Hg at rest, measured by means of right heart catheterization. Patients with pulmonary hypertension undergoing surgical procedures such as hemiarthroplasty present a high risk of fatal complications. Nonetheless, there are no widely accepted protocols explaining their perioperative care in great detail. Case presentation: We present a case with an 89-years-old patient, with comorbidities such as GOLD 4D chronic obstructive pulmonary disease (COPD) and, as a consequence of this, severe pulmonary hypertension with signs of right ventricular dysfunction, thus requiring of pulmonary vasodilator, that has suffered a subcapital hip fracture requiring urgent surgery. Surgery is carried out successfully, under regional lumbar-sacral plexus block and sedation assisted by non-invasive ventilation. Conclusion: Multidisciplinary specialized treatment, preoperative optimization, as well as the careful selection of both the surgical and anesthetic techniques to be used, are among the strategies that improve the perioperative outcome in patients with pulmonary hypertension with right ventricle systolic dysfunction. Regional lumbar-sacral plexus block plus sedation is a technique that maintains hemodynamic stability;however, these patients require advance measures and postoperative monitoring under intensive care.

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.

Intention Formation Process for the Use of Tracheostomy and Invasive Ventilation in Patients with Amyotrophic Lateral Sclerosis

Background: Little is known about the intention formation process regarding the use of tracheostomy and invasive ventilation (TIV) in amyotrophic lateral sclerosis (ALS) patients in the course of disease progression. Objective: To clarify the intention formation process in the use of TIV in ALS patients for the purpose of providing decision-making support. Methods: We conducted a follow-up study of 14 patients using semi-structured interviews, participant observation, and medical records review. Results: The patients’ various intentions regarding the use of TIV were formed as their symptoms progressed (e.g., declining motor, swallowing, and respiratory functions). Other factors influencing their decision were their considerations, such as their ability to communicate after receiving TIV treatment, the degree of support they would receive from professionals after TIV treatment, palliative care for physical distress, value of life after TIV treatment, and to what degree they would be a burden on their families. Conclusion: Patients’ intentions regarding the use of TIV were diverse and changeable. The decision of whether or not to use TIV was made out of conviction as well as considering individual experiences of symptom progression and quality of life after TIV use.

Effect of Oxygen Therapy by Venturi Mask versus Non Invasive Ventillation on the Outcome of Patients Who Devolope Hypoxia after Open Heart Surgery

Background: Cardiothoracic surgery is a common cause of acute respiratory failure and is associated with increased morbidity and mortality. We aimed to compare the outcomes of open heart surgery patients treated using oxygen delivery devices with patients who receive NIV as a first-line therapy for hypoxemic respiratory failure. Materials and Methods: 40 patients who developed acute hypoxemic respiratory failure after open heart surgery and admitted to cardiothoracic ICU 20 patients received NIV and 20 patient received oxygen by venture mask. For all patients the following measurements were performed before and after CPAP AND Venture use: CBC, blood urea, serum creatinine body temperature, chest X-ray, Arterial blood gases (arterial pH, sodium bicarbonate, pcO2, SpO2 and PaO2-to-FiO2 ratio). Results: Mean PO2 and SO2 have increased after using of both venture and Cpap, increase in both PCO2 and HCO3 levels after using Venturi mask, CPAP mask was superior to venturi mask in avoiding the need of intubation, decreasing The ICU stay median length and also median length of hospitalization, all were lower in CPAP group than venture group. Also the mortality rate was lower in CPAP group than the venturi group. Conclusion: Using CPAP mask in severe AHRF following open heart surgery can avoid intubation, decreases the levels of tachypnea and arterial hypoxemia, decreases ICU stay, the length of hospitalization and also decreases the mortality rate compared with patients receiving high-concentration oxygen therapy with venture mask.

Use of inflammatory markers as predictor for mechanical ventilation in COVID-19 patients with stagesⅢb-Ⅴchronic kidney disease?

BACKGROUND Studies have shown elevated C-reactive protein(CRP)to predict mechanical ventilation(MV)in patients with coronavirus disease 2019(COVID-19).Its utility is unknown in patients with chronic kidney disease(CKD),who have elevated baseline CRP levels due to chronic inflammation and reduced renal clearance.AIM To assess whether an association exists between elevated inflammatory markers and MV rate in patients with stagesⅢb-ⅤCKD and COVID-19.METHODS We conducted a retrospective cohort study on patients with COVID-19 and stagesⅢb-ⅤCKD.The primary outcome was the rate of invasive MV,the rate of noninvasive MV,and the rate of no MV.Statistical analyses used unpaired t-test for continuous variables and chi-square analysis for categorical variables.Cutoffs for variables were CRP:100 mg/L,ferritin:530 ng/mL,D-dimer:0.5 mg/L,and lactate dehydrogenase(LDH):590 U/L.RESULTS 290 were screened,and 118 met the inclusion criteria.CRP,D-dimer,and ferritin were significantly different among the three groups.On univariate analysis for invasive MV(IMV),CRP had an odds ratio(OR)-5.44;ferritin,OR-2.8;LDH,OR-7.7;D-dimer,OR-3.9,(P<0.05).The admission CRP level had an area under curve-receiver operator characteristic(AUROC):0.747 for the IMV group(sensitivity-80.8%,specificity-50%)and 0.663 for the non-IMV(NIMV)group(area under the curve,sensitivity-69.2%,specificity-53%).CONCLUSION Our results demonstrate a positive correlation between CRP,ferritin,and D-dimer levels and MV and NIMV rates in CKD patients.The AUROC demonstrates a good sensitivity for CRP levels in detecting the need for MV in patients with stagesⅢb-ⅤCKD.This may be because of the greater magnitude of increased inflammation due to COVID-19 itself compared with increased inflammation and reduced clearance due to CKD alone.

Effect of metronome rates on the quality of bag-mask ventilation during metronome-guided 30:2 cardiopulmonary resuscitation:A randomized simulation study

BACKGROUND: Metronome guidance is a feasible and effective feedback technique to improve the quality of cardiopulmonary resuscitation(CPR). The rate of the metronome should be set between 100 to 120 ticks/minute and the speed of ventilation may have crucial effect on the quality of ventilation. We compared three different metronome rates(100, 110, 120 ticks/minute) to investigate its effect on the quality of ventilation during metronome-guided 30:2 CPR.METHODS: This is a prospective, randomized, crossover observational study using a Respi Trainer r. To simulate 30 chest compressions, one investigator counted from 1 to 30 in cadence with the metronome rate(1 count for every 1 tick), and the participant performed 2 consecutive ventilations immediately following the counting of 30. Thirty physicians performed 5 sets of 2 consecutive(total 10) bag-mask ventilations for each metronome rate. Participants were instructed to squeeze the bag over 2 ticks(1.0 to 1.2 seconds depending on the rate of metronome) and defl ate the bag over 2 ticks. The sequence of three different metronome rates was randomized.RESULTS: Mean tidal volume significantly decreased as the metronome rate was increased from 110 ticks/minute to 120 ticks/minute(343±84 m L vs. 294±90 m L, P=0.004). Peak airway pressure significantly increased as metronome rate increased from 100 ticks/minute to 110 ticks/minute(18.7 vs. 21.6 mm Hg, P=0.006).CONCLUSION: In metronome-guided 30:2 CPR, a higher metronome rate may adversely affect the quality of bag-mask ventilations. In cases of cardiac arrest where adequate ventilation support is necessary, 100 ticks/minute may be better than 110 or 120 ticks/minute to deliver adequate tidal volume during audio tone guided 30:2 CPR.

Respiratory Volume Monitoring to Assess the Effect of Airway Maneuvers on Ventilation during Upper Endoscopy

Introduction: Propofol use during endoscopic procedures has become increasingly popular and assessing and maintaining airway patency is a significant challenge. Anesthesiologists often use airway maneuvers to maintain airway patency and ventilation during procedural sedation. A novel, non-invasive, Respiratory Volume Monitor (RVM) that provided continuous, real-time measurements of minute ventilation (MV), tidal volume (TV) and respiratory rate (RR) was used to monitor respiratory performance before, during, and after endoscopic procedures, quantify MV changes before and after airway maneuvers, and to quantify propofol-induced respiratory depression. Methods: RVM traces were obtained from 25 patients undergoing sedation for endoscopic procedures. Airway maneuvers were performed in 19/25 patients. All 25 patients received propofol as the primary sedative. Results: Forty-five airway maneuvers were performed. During these maneuvers, all respiratory parameters increased relative to pre-maneuver levels. On average, MV increased by 24% ± 5% (mean ± SEM), TV 14% ± 5% and RR: 17% ± 6%. The cohort average MVBASELINE was 9.5 ± 0.7 L/min (TV = 670 ± 60 ml, RR = 15 ± 0.7). Following propofol MV decreased transiently, reaching nadir five minutes after the last dose of propofol at 82% ± 10% of baseline (MV = 7.5 ± 1.0 L/min). The reduction in MV was driven by reduction in TV, not RR. Conclusions: Data demonstrated that RVM was able to track changes in ventilation and was able to quantify respiratory changes following airway maneuvers. All patients had a significant reduction in ventilatory volumes after propofol. Five minutes after the last dose of propofol, MV and TV were significantly reduced while RR was not, suggesting that monitoring respiratory rate alone was not a sufficient indicator of respiratory status.

Mechanical ventilation and outcomes in COVID-19 patients admitted to intensive care unit in a low-resources setting: A retrospective study

Objective:To describe the strategies and outcomes of mechanical ventilation in a poorly equipped facility.Methods:This retrospective descriptive study included patients with COVID-19 who were admitted to the intensive care unit(ICU)and mechanically ventilated between September 1,2020,and May 31,2021.Data were collected from medical records and databases.Results:54 Patients aged(62.9±13.3)years were included.Among these cases,79.6%had at least one comorbidity.On admission,all patients had hypoxia.The median peripheral oxygen saturation in room air was 76%(61%,83%).Non-invasive ventilation(NIV)was performed in 75.9%of the patients,and invasive mechanical ventilation(IMV)in 68.5%.IMV was performed on patients due to severe coma(8.1%),failure of standard oxygen therapy(27.0%),and failure of NIV(64.9%).An arterial blood gas test was performed in 14.8%of the patients.NIV failed in 90.2%of cases and succeeded in 9.8%.IMV was successful in 5.4%of cases,vs.94.6%of mortality.The overall mortality rate of patients on ventilation in the ICU was 88.9%.The causes of death included severe respiratory distress syndrome(85.2%),multiple organ failure(14.8%),and pulmonary embolism(13.0%).Conclusions:The ventilation management of COVID-19 patients in the ICU with NIV and IMV in a scarce resource setting is associated with a high mortality rate.Shortcomings are identified in ventilation strategies,protocols,and monitoring.Required improvements were also proposed.

Clinical Study of P_(ET)CO_2 in One-lung Ventilation

Fourty-eight patients (ASA physical status Ⅰ - Ⅱ) undergoing selected thoracotomy and pulmonectomy were studied. They were divided into two groups according to different respiratory modes, two-lung ventilation (TLV) and onelung ventilation (OLV) or TLV and OLV with a Bain cyclic system for CPAP on the side of operated lung. PETCO2 and PaCO2 were measured after 30 min TLV,30 min and 60 min OLV, and repeated TLV (R-TLV) 30 min after pulmonectomy, to evaluate the difference between PETCO2 and PaCO2 in OLV and to observethe effect of abating hypoxemia and discharge of CO2 in OLV with Bain system.Our results showed that the PaCO2 and PETCO2 in different test groups were normal though the measured values in OLV were slightly higher than that in TLV (P<0. 05) , and then they were recovered after R-TLV (P>0. 05). There was nosignificant difference between group 1. and 2. in OLV (P>0. 05). There was aclose correlation between PETCO2 and PaCO2 (P<0. 05). The differences of the calculated P(a-ET)CO2 and radio of PETCO2/PaCO2 in different ventilation modes were not significant. Hypoxemia in OLV was corrected by Bain system, but the discharge of CO2 was not affected. The results showed that measurement of PET CO2 as a non-invasive procedure can be commonly used to monitor OLV.

The Value of Positive Pressure Ventilations for Clients in Acute Respiratory Distress as a Result of Cardiac and Pulmonary Issues

Objective: Research was conducted to examine benefits to using non-invasive ventilation (NIV) or continuous positive airway pressure (CPAP) early in the treatment of respiratory distress caused by pulmonary edema, chronic obstructive pulmonary disease (COPD) and asthma. Limitations to successful NIV and CPAP therapy were evaluated to determine how prolonged initiation of treatment may lead to hypoxemia (decreased oxygen in the blood) and hypercapnia (increased carbon dioxide in the blood) resulting in poor outcomes. Method: Reviews of literature from nursing and allied health data bases (CINAHL and ProQuest) with terms pulmonary edema, positive pressure device and non-invasive ventilation from 2010 to 2014 were used. Studies were conducted in the hospital and prehospital settings. Results: The literature search located 7 articles from CINAHL and 25 articles from ProQuest. A total of 6 of these articles were analyzed. Additional sources of data were obtained from Ignatavicius and Workman (2013) Medical-Surgical Nursing Patient-Centered Collaborative Care 7th edition and American Journal of Nursing (02/2013) Volume 113: 2. Conclusion: All of the articles concluded that early initiation of continuous positive airway pressure ventilations in the short-term was beneficial;however, late initiation of therapy required additional interventions. The studies indicated that early use of positive airway pressure in acute respiratory distress improved breath rate, heart rate and blood pressure. The use of positive airway pressure for respiratory distress may decrease the need for endotracheal intubation.

Non-invasive versus invasive mechanical ventilation for respiratory failure in severe acute respiratory syndrome

Background Severe acute respiratory syndrome is frequently complicated by respiratory failure requiring ventilatory support.We aimed to compare the efficacy of non-invasive ventilation against invasive mechanical ventilation treating respiratory failure in this disease.Methods Retrospective analysis was conducted on all respiratory failure patients identified from the Hong Kong Hospital Authority Severe Acute Respiratory Syndrome Database.Intubation rate,mortality and secondary outcome of a hospital utilizing non-invasive ventilation under standard infection control conditions(NIV Hospita1)were compared against 13 hospitals using solely invasive ventilation(IMV Hospitals).Multiple logistic regression analyses with adjustments for confounding variables were performed to test for association between outcomes and hospital groups.Results Both hospital groups had comparable demographics and clinical profiles,but NIV Hospital(42 patients)had higher lactate dehydrogenase ratio and worse radiographic score on admission and ribavirin-corticosteroid commencement.Compared to IMV Hospitals(451 patients).NIV Hospital had lower adjusted odds ratios for intubation(0.36,95%C10.164-0.791,P=0.011)and death(0.235.95%C10.077-0.716,P=0.O 11),and improved earlier after pulsed steroid rescue.There were no instances of transmission of severe acute respiratory syndrome among health care workers due to the use of non-invasive ventilation.Conclusion Compared to invasive mechanical ventilation,non-invasive ventilation as initial ventilatory support for acute respiratory failure in the presence of severe acute respiratory syndrome appeared to be associated with reduced intubation need and mortality.

Application of non-invasive ventilation in China over 20 years

Over the last 20 years, the application of non-invasive ventilation （NIV） in China has progressively increased both in the hospital and extrahospital setting. The history of the NIV and its increasing spread in the clinical practice over China are one of the most important results of the cooperation between medicine and non-invasive mechanic technology.

Long-term non-invasive positive pressure ventilation in severe stable chronic obstructive pulmonary disease： a meta-analysis

Background The evidence for non-invasive positive pressure ventilation （NIPPV） used in patients with severe stable chronic obstructive pulmonary disease （COPD） is insufficient. The aim of the meta-analysis was to assess the treatment effects of long-term NIPPV on gas change, lung function, health-related quality of life （HRQL）, survival and mortality in severe stable COPD patients. Methods Randomized controlled trials （RCTs） and crossover studies comparing the treatment effects of NIPPV with conventional therapy were identified from electronic databases and reference lists from January 1995 to August 2010. Two reviewers independently assessed study quality. Data were combined using Review Manager 5.0. Both pooled effects and 95% confidence intervals were calculated. Results Five RCTs and one randomized crossover study with a total of 383 severe stable COPD patients were included NIPPV improved gas change significantly when using a higher inspiratory positive airway pressures. The weighted mean difference （WMD） for the partial pressure of carbon dioxide in artery （PaCO2） was -3.52 （-5.26, -1.77） mmHg and for the partial pressure of oxygen in artery （PaO2） 2.84 （0.23, 5.44） mmHg. There were significant improvements in dyspnea and sleep quality, but gained no benefits on lung function. The standardized mean difference （SMD） for the forced expiratory volume in 1 second （FEV1） was 0.00 （0.29, 0.29）. And the benefits for exercise tolerance, mood, survival and mortality remained unclear. Conclusions Patients with severe stable COPD can gain some substantial treatment benefits when using NIPPV, especially improvements in gas change, dyspnea and sleep quality. Studies of high methodological quality with large population, especially those based on a higher inspiratory positive airway pressures are required to provide more evidences.

Analysis of risk factors for hospital mortality in patients with chronic obstructive pulmonary diseases requiring invasive mechanical ventilation

Background Accurate prediction for prognosis is important for hospitalized patients with chronic obstructive pulmonary disease （COPD） requiring invasive mechanic ventilation （IMV） and for their family members to make end-of-life decisions. The response to therapy in such a patient population has rarely been investigated. The aim of the study was to evaluate the risk factors in these patients and investigate their response to IMV and the relationship between their responses and prognosis. Methods A cohort of 138 patients with COPD requiring IMV≥12 hours for acute respiratory failure of diverse etiological factors during a 4-year period were retrospectively studied using prospectively gathered data. All variables potentially related to hospital mortality were evaluated by univariate and multiple stepwise logistic regression analysis. Results The mean age of all patients investigated was （65.7±11.6） years and the hospital mortality was 39.9% （31.1% with COPD exacerbation）. Correction of acidosis （pHi〉7.30） was seen in 58 patients （69.9%） in survivors but only 12 patients （21.8%） in nonsurvivors （P〈0.05） after ventilation. Using multivariate logistic analysis, the variables independently associated with hospital mortality were a higher acute physiology score before intubation, lower pH value measured 24 hours after the onset of ventilation and development of multiorgan dysfunction syndrome （MODS）. Conclusions In COPD patients requiring IMV, the postintubation pH value can not only reflect patients＇ response to treatment, but also serve as an independent determinant of hospital mortality apart from other risk factors such as a higher preintubation APACHE II score and development of MODS. A close correlation between the response to IMV and prognosis was proved in these patients.

Effect of noninvasive positive pressure ventilation on weaning success in patients receiving invasive mechanical ventilation： a meta-analysis

Background Noninvasive positive pressure ventilation （NIPPV） has been proposed to shorten the duration of mechanical ventilation in intubated patients, especially those who fail initial weaning from invasive mechanical ventilation （IMV）. However, there are also some discrepancies in terms of weaning success or failure, incidence of re-intubation, complications observed during study and patient outcomes. The primary objective of this update was to specifically investigate the role of NIPPV on facilitating weaning and avoiding re-intubation in patients intubated for different etiologies of acute respiratory failure, by comparing with conventional invasive weaning approach. Methods We searched randomized controlled trials （RCTs） comparing noninvasive weaning of early extubation and immediate application of NIPPV with invasive weaning in intubated patients from PubMed, Embase, Cochrane Central Register of Controlled Trials, Web of Knowledge and Springerlink databases. Records from conference proceedings and reference lists of relevant studies were also identified. Results A total of 11 RCTs with 623 patients were available for the present analysis. Compared with IMV, NIPPV significantly increased weaning success rates （odds ratio （OR）： 2.50, 95% confidence interval （C/）： 1.46-4.30, P=0.0009）, decreased mortality （OR： 0.39, 95% CI： 0.20-0.75, P=0.005）, and reduced the incidence of ventilator associated pneumonia （VAP） （OR： 0.17, 95% CI： 0.08-0.37, P 〈0.00001） and complications （OR： 0.22, 95% CI： 0.07-0.72, P=0.01）. However, effect of NIPPV on re-intubation did not reach statistical difference （OR： 0.61, 95% CI： 0.33-1.11, P=0.11）. Conclusions Early extubation and immediate application of NIPPV is superior to conventional invasive weaning approach in increasing weaning success rates, decreasing the risk of mortality and reducing the incidence of VAP and complications, in patients who need weaning from IMV. However, it should be applied with caution, as there is insufficient beneficial evidence to definitely recommend it in terms of avoidinQ re-intubation.

Prognosis and weaning of elderly multiple organ dysfunction syndrome patients with invasive mechanical ventilation

Background Elderly multiple organ dysfunction syndrome （MODS） patients receiving invasive mechanical ventilation have poor prognosis in intensive care units （ICUs）.We studied the usefulness of four commonly used severity scores and extrapulmonary factors that affected weaning to predict outcome of such patients.Methods Clinical data of 197 patients on admission to ICUs （from January 2009 to June 2012） were used retrospectively.The Acute Physiology and Chronic Health Evaluation （APACHE） Ⅱ,APACHE Ⅲ,Sample Acute Physiological Score （SAPS） Ⅱ and MODS scores were calculated.All the patients were grouped into survivors and nonsurvivors according to the prognosis.Patients,who weaned from ventilator （n=154）,were subdivided into a successful weaning group and a failed weaning group.The receiver operating characteristic （ROC） curves and Logistic regression was used for prognostic and weaning assessment.Results Based on the outcomes,the areas under the ROC of APACHE Ⅱ,APACHE Ⅲ,SAPS Ⅱ,and MODS were 0.837,0.833,0.824,and 0.837,respectively.The Logistic regression analysis revealed that the odds ratio （OR） of underlying lung diseases,serum albumin and creatinine,and the number of organ failures was 2.374,0.920,1.003,and 1.547.APACHE Ⅱ scores on admission performed excellent （ROC：0.921） on the weaning assessments.Conclusions APACHE Ⅱ and MODS systems were marginally better for evaluating the prognosis of elderly MODS patients who received invasive mechanical ventilation.Underlying lung diseases,serum albumin,serum creatinine and the number of organ failures were independent prognostic factors.Using the APACHE Ⅱ scores on admission before weaning may increase the likelihood of successful weaning.（ClinicalTrial.gov identifier NCT01802983）.

Longer duration of initial invasive mechanical ventilation is still a crucial risk factor for moderate‑to‑severe bronchopulmonary dysplasia in very preterm infants:a multicentrer prospective study

Objectives We aimed to evaluate the risk factors for moderate-to-severe bronchopulmonary dysplasia(BPD)and focus on discussing its relationship with the duration of initial invasive mechanical ventilation(IMV)in very preterm neonates less than 32 weeks of gestational age(GA).Methods We performed a prospective cohort study involving infants born at 23–31 weeks of GA who were admitted to 47 different neonatal intensive care unit(NICU)hospitals in China from January 2018 to December 2021.Patient data were obtained from the Sina-northern Neonatal Network(SNN)Database.Results We identified 6538 very preterm infants,of whom 49.5%(3236/6538)received initial IMV support,and 12.6%(823/6538)were diagnosed with moderate-to-severe BPD symptoms.The median duration of initial IMV in the moderateto-severe BPD group was 26(17–41)days,while in the no or mild BPD group,it was 6(3–10)days.The incidence rate of moderate-to-severe BPD and the median duration of initial IMV were quite different across different GAs.Multivariable logistic regression analysis showed that the onset of moderate-to-severe BPD was significantly associated with the duration of initial IMV[adjusted odds ratio(AOR):1.97;95%confidence interval(CI):1.10–2.67],late-onset neonatal sepsis(LONS),and patent ductus arteriosus(PDA).Conclusion In this multicenter cohort study,the duration of initial IMV was still relatively long in very premature infants,and the longer duration of initial IMV accounts for the increased risk of moderate-to-severe BPD.