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.

Effect of lung lavage via fiber bronchoscope combined with non-invasive positive pressure ventilation on the blood gas results and systemic state of patients with COPD complicated by severe pneumonia

Objective: To discuss the effect of lung lavage via fiber bronchoscope combined with non-invasive positive pressure ventilation on the blood gas results and systemic state of patients with COPD complicated by severe pneumonia. Methods: A total of 68 patients with COPD complicated by severe pneumonia who were treated in the hospital between November 2015 and April 2017 were collected, retrospectively analyzed and then divided into the group A (n=35) who received noninvasive positive pressure ventilation and the group B (n=33) who received lung lavage via fiber bronchoscope combined with non-invasive positive pressure ventilation. The differences in arterial blood gas and serum index levels were compared between the two groups before and after treatment. Results: Before treatment, there was no statistically significant difference in arterial blood gas index levels as well as serum contents of inflammatory mediators, stress hormones and myocardial enzyme spectrum indexes between the two groups. After treatment, arterial blood gas indexes PH and PaO2 levels of group B were higher than those of group A;serum inflammatory mediators HMGB1, PCT and hs-CRP contents were lower than those of group A;serum stress hormones Cor, AngⅠ and AngⅡcontents were lower than those of group A;serum myocardial enzyme spectrum indexesα-HBDH and cTn-Ⅰ contents were lower than those of group A. Conclusion: Lung lavage via fiber bronchoscope combined with non-invasive positive pressure ventilation can effectively optimize the arterial blood gas levels, reduce systemic inflammatory stress state and protect the myocardial function of patients with COPD complicated by severe pneumonia.

Influence of Leakage from Non-Invasive Positive Pressure Ventilation Mask on FiO₂Value Delivered by Home Oxygen Therapy Concentrator: A Bench Study on Simulating Patients with Chronic Obstructive Pulmonary Disease

Introduction: During the application of non-invasive positive pressure ventilation (NPPV) therapy in home mechanical ventilation (HMV), leaks in the NPPV mask may occur owing to the position of the mask due to conditions such as skin disorders. Methods: To investigate whether such a leak affects FiO2 supplied to the alveoli, we simulated a patient with chronic obstructive pulmonary disorder during NPPV in HMV. In addition, FiO2 was measured in the portion assumed to be the mouth and lungs while setting the flow of the oxygen concentrator and leak amount based on a previous study. Results: FiO2 supplied to the lungs increased statistically significantly upon increasing the amount of leak (P Conclusions: We observed that FiO2 supplied to alveoli can be reduced by a leak in the NPPV mask. Because our results differ from those previously reported, we believe that further studies should reassess the selection of respirators and oxygen concentrators.

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.

Early use of non-invasive positive pressure ventilation for acute exacerbations of chronic obstructive pulmonary disease:a multicentre randomized controlled trial

Background Respiratory muscle fatigue plays an important role in acute exacerbations of chronic obstructivepulmonary disease (AECOPD)·In previous clinical studies, non-invasive positive pressure ventilation (NPPV)was proved to be successful only for AECOPD patients with severe respiratory failure·We hypothesized that, theoutcomes of AECOPD would be improved if NPPVis early (within 24 to 48 hours of admission) administered inthose patients with respiratory muscle fatigue and mild respiratory insufficiency, especially in patients withoutfulfilling the conventional criteria of mechanical ventilatory support·Methods Aprospective multicentre randomized controlled trial was conducted in19 hospitals in China over16months·Three hundred and forty-two AECOPD patients with pH≥7·25 and PaCO2>45 mmHg were recruitedon general ward and randomly assigned to standard medical treatment (control group) or early administration ofadditional NPPV (NPPV group)·Results The characteristics of two groups on admission were similar·The number of AECOPD patientsrequiring intubations in NPPV group was much fewer than that of the control group (8/171 vs 26/71,P=0·002)·Subgroup analysis showed the needs for intubation in mildly (pH≥7·35) and severe (pH<7·30)acidotic patients in NPPVgroup were both decreased (9/80 vs2/71,P=0·047 and 8/30 vs3/43,P=0·048,respectively)·The mortality in hospital was reduced slightly by NPPV but with no significant difference (7/171vs 12/171,P=0·345)·Respiratory rate (RR),scale for accessory muscle use and arterial pHimproved rapidlyat the first 2 hours only in patients of NPPV group·After 24 hours, the differences of pH, PaO2, scale foraccessory muscle use and RR in NPPV group [(7·36±0·06) mmHg, (72±22) mmHg, (2·5±0·9) /min,(22±4) /min] were statistically significant compared with control group (7·37±0·05) mmHg, (85±34)mmHg, (2·3±1·1) /min, (21±4) /min,P<0·01 for all comparisons]·Conclusions The early use of NPPV on general ward improves arterial blood gas and respiratory pattern,decreases the rate of need for intubation in AECOPD patients·NPPV is indicative for alleviating respiratorymuscle fatigue and preventing respiratory failure from exacerbation·

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.

Sleep Quality for Patients Receiving Noninvasive Positive Pressure Ventilation and Nasal High-Flow Oxygen Therapy in an ICU: Two Case Studies

Aim: The purpose of this case study was to examine the sleep quality of patients receiving noninvasive positive pressure ventilation (NPPV) or nasal high-flow oxygen therapy (NHF) in an intensive care unit and to investigate what types of nursing support are offered to such patients. Methods: We examined one patient each for NPPV and NHF. Polysomnography (PSG), review of the patient charts, and semi-structured interviews were used to collect the data for analysis. Results: Patients treated with NPPV or NHF demonstrated a noticeable reduction in deep sleep, with most of their sleep being shallow. Their sleep patterns varied greatly from those of healthy individuals. These results suggest that, in addition to experiencing extremely fragmented sleep, sleep in these patients was more likely to be interrupted by nursing interventions, such as during auscultation of breath sounds. Furthermore, it was revealed that “anxiety or discomfort that accompanies the mask or air pressure” in patients treated with NPPV and “discomfort that accompanies the nasal cannula or NHF circuit” in patients treated with NHF may be primary causes of disrupted sleep. Our results suggest a need for nursing care aimed at improving sleep quality in patients treated with NPPV or NHF.

Effect of adjuvant noninvasive positive pressure ventilation on blood gas parameters, cardiac function and inflammatory state in patients with COPD and type II respiratory failure

Objective:T o analyze the effect of adjuvant noninvasive positive pressure ventilation on blood gas parameters, cardiac function and inflammatory state in patients with chronic obstructive pulmonary disease (COPD) and type II respiratory failure. Methods:90 patients with COPD and type II respiratory failure were randomly divided into observation group and control group (n=45). Control group received conventional therapy, observation group received conventional therapy+adjuvant noninvasive positive pressure ventilation, and differences in blood gas parameters, cardiac function, inflammatory state, etc., were compared between two groups of patients 2 weeks after treatment. Results:Arterial blood gas parameters pH and alveolar-arterial partial pressure of oxygen [P(A-a)O2] levels of observation group were higher than those of control group while, potassium ion (K+), chloride ion (Cl-) and carbon dioxide combining power (CO2CP) levels were lower than those of control group 2 weeks after treatment;echocardiography parameters Doppler-derived tricuspid lateral annular systolic velocity (DTIS) and pulmonary arterial velocity (PAV) levels were lower than those of control group (P<0.05) while pulmonary artery accelerating time (PAACT), left ventricular end-diastolic dimension (LVDd) and right atrioventricular tricuspid annular plane systolic excursion (TAPSE) levels were higher than those of control group (P<0.05);serum cardiac function indexes adiponectin (APN), Copeptin, N-terminal pro-B-type natriuretic peptide (NT-proBNP), cystatin C (CysC), growth differentiation factor-15 (GDF-15) and heart type fatty acid binding protein (H-FABP) content were lower than those of control group (P<0.05);serum inflammatory factors hypersensitive C-reactive protein (hs-CRP), tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), IL-8, IL-10, and transforming growth factor-β1 (TGF-β1) content were lower than those of control group (P<0.05). Conclusions:Adjuvant noninvasive positive pressure ventilation can optimize the blood gas parameters, cardiac function and inflammatory state in patients with COPD and type II respiratory failure, and it is of positive significance in improving the overall treatment outcome.

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.

Clinical Analysis of Early Application of Bi-level Positive Airway Pressure ventilation in the Treatment of COPD with Type II Respiratory Failure

Objective:To analyze the clinical efficacy of early application of bi-level positive airway pressure ventilation in the treatment of COPD with type II respiratory failure.Method:A total of 58 patients with COPD and type II respiratory failure admitted to our hospital from January 2017 to January 2019 were randomly divided into observation group and control group,with 29 cases in each group.Among them,the control group was received routine treatment while the observation group was treated with bi-level positive pressure airway ventilation in addition of conventional treatment.The arterial blood gas analysis,mortality rate and hospitalization time of these two groups before and after treatment were compared.Result:The blood pH,partial pressure of oxygen(PaO2)and arterial oxygen saturation(SaO2)of these two groups were significantly higher after the treatment while PaO2 alone was decreased.The difference was statistically significant(P<0.05).The results of arterial blood gas analysis in the observation group were significantly improved compared with those before treatment.The mortality rate and hospitalization time were significantly less than the control group,and the difference was statistically significant(P<0.05).Conclusion:Early clinical application of bi-level positive airway pressure ventilation in the treatment of COPD with type II respiratory failure has a significant clinical effect in reducing the mortality rate and hospitalization time of patients,and thus it is worthy of clinical application.

Clinical efficacy of mask continuous positive airway pressure mechanical ventilation in children with severe pneumonia

Objective: To investigate the clinical effects of the mask continuous positive airway pressure (CPAP) mechanical ventilation in children with severe pneumonia. Methods: A total of 100 cases of children with severe pneumonia were randomly divided into two groups, study group with 50 children and control group with 50 children. These 100 children were given comprehensive treatment measures: treatment of anti-infection, anti-respiratory failure, anti-heart failure (if necessary), relieving cough and reducing sputum, aerosol inhalation, limited fluid volume, nutrition support etc. Children in the study group were added mask continuous positive airway pressure mechanical ventilation (CPAP). Children in the control group were added ordinary mask oxygen inhalation. Investigated and checked the treatment effect in these two groups. Results: After treatment, SaO2, PaO2 in both two groups were showed significantly higher than before the treatment. PaO2 of the study group is obviously higher than the control group. The oxygen inhalation time of the study group was obviously lesser than the control group. The total effective rate of the study group was significantly higher than the control group which was 96.0% vs 66.0%. Conclusion: The mask continuous positive airway pressure (CPAP) mechanical ventilation can significantly improve the related symptoms and blood gas status of the children with severe pneumonia, shorten the oxygen inhalation time and had remarkable effect.

Impact of noninvasive positive pressure ventilation on the gene expression of ubiquitin system of skeletal muscle in patients with acute exacerbation of chronic obstructive pulmonary disease

Objective:To investigate the change and relativity of noninvasive positive pressure ventilation(NIPPV)on the gene expression of ubiquitin system of skeletal muscle in patient with acute exacerbation of chronic obstructive pulmonary disease(AECOPD).Methods:80 patients with AECOPD were divided into two groups based on whether the NIPPV treatment was given or not,38 cases in the study group and 42 in the control group.The blood gas analysis and pulmonary function were monitored and recorded before and 14 days after treatment.A skeletal muscle biopsy was performed 14 days after therapy.The mRNA expression of ribosomal protein S21(RPS21)and ubiquitin in skeletal muscle cell were measured by RT-PCR.Results:After 14 days treatment,the levels of PaCO_(2),PaO_(2),PH and FEV_(1)% in the NIPPV group improved much better than in the control group(p<.05).The gene expression of RPS21 and ubiquitin was obviously lower in the study group than in the control group(p<.05).The level of RPS21 was negatively related with PaO_(2),PH and FEV1%,and the level of ubiquitin was negatively related with PaO_(2) and FEV1%,but positively correlated with PaCO_(2).The area under the ROC curves of RPS21,ubiquitin,PaCO_(2) and FEV_(1)% were 0.771,0.885,0.821 and 0.734 respectively in the study group.The cut-off points were 103.978,8.128,45.350 and 51.350 respectively.The sensitivity evaluation of acid poisoning was 90.9%,and the specificities for each were 75%,75%,50% and 50%.Conclusions:NIPPV is effective for AECOPD patients through the gene expression of ubiquitin system of skeletal muscle.

Bi-level Nasal Positive Airway Pressure(BiPAP)versus Nasal Continuous Positive Airway Pressure(CPAP)for Preterm Infants with Birth Weight Less Than 1500g and Respiratory Distress Syndrome Following INSURE Treatment:A Two-center Randomized Controlled Trial

The present study aimed to examine the effectiveness of bi-level positive airway pressure(BiPAP)versus continuous positive airway pressure(CPAP)in preterm infants with birth weight less than 1500 g and respiratory distress syndrome(RDS)following intubation-surfactant-extubation(INSURE)treatment.A two-center randomized control trial was performed.The primary outcome was the reintubation rate of infants within 72 h of age after INSURE.Secondary outcomes included bronchopulmonary dysplasia(BPD),necrotizing enterocolitis(NEC),retinopathy of prematurity(ROP)and incidences of adverse events.Lung function at one year of corrected age was also compared between the two groups.There were 140 cases in the CPAP group and 144 in the BiPAP group.After INSURE,the reintubation rates of infants within 72 h of age were 15%and 11.1%in the CPAP group and the BiPAP group,respectively(P>0.05).Neonates in the BiPAP group was on positive airway pressure(PAP)therapy three days less than in the CPAP group(12.6 d and 15.3 d,respectively,P<0.05),and on oxygen six days less than in the CPAP group(20.6 d and 26.9 d,respectively,P<0.05).Other outcomes such as BPD,NEC,ROP and feeding intolerance were not significantly different between the two groups(P>0.05).There was no difference in lung function at one year of age between the two groups(P>0.05).In conclusion,after INSURE,the reintubation rate of infants within 72 h of age was comparable between the BiPAP group and the CPAP group.BiPAP was superior to CPAP in terms of shorter durations(days)on PAP support and oxygen supplementation.There were no differences in the incidences of BPD and ROP,and lung function at one year of age between the two ventilation methods.

Airway Pressure Release Ventilation Improves Oxygenation in a Patient with Pulmonary Hypertension and Abdominal Compartment Syndrome

The following case describes the favorable application of airway pressure release ventilation (APRV) in a patient with pulmonary hypertension who developed respiratory failure and abdominal compartment syndrome after abdominal closure from an incarcerated umbilical hernia. A 66-year-old male with past medical history of restrictive lung disease, obstructive sleep apnea and pulmonary hypertension, presented to the operating room for an incarcerated inguinal hernia. After abdominal closure, he gradually developed decreased oxygen saturation and hypotension. APRV was initiated during post operative day 2 after inability to maintain adequate oxygen saturation with resultant hypotension on pressure control ventilation with varying degrees of positive end expiratory pressure and 100% inspired oxygen concentration. The initial set high pressure on APRV was 35 mm Hg. Yet, in lieu of decreasing lung compliance, it peaked at 50 mm Hg. Eventually, inhaled Nitric Oxide was initiated post operative day 3 due to increasing pulmonary arterial pressures. A bedside laparotomy was eventually performed when bladder pressures peaked to 25 mm Hg. APRV gradually and temporally improved the oxygen saturation and decreased the pulmonary arterial pressures with subsequent increase in systemic blood pressures. APRV promoted alveolar recruitment and decreased the shunting associated with abdominal compartment syndrome. Better oxygen saturations lead to increases in blood pressure by decreasing the effects of hypoxic pulmonary vasoconstriction on the right ventricle (RV). In patients with decreasing lung compliance and pulmonary comorbidities, APRV appears safe and allows for improve oxygenation, after failure with conventional modes of ventilation.

Role of proning and positive end-expiratory pressure in COVID-19

The novel coronavirus,which was declared a pandemic by the World Health Organization in early 2020 has brought with itself major morbidity and mortality.It has increased hospital occupancy,heralded economic turmoil,and the rapid transmission and community spread have added to the burden of the virus.Most of the patients are admitted to the intensive care unit(ICU)for acute hypoxic respiratory failure often secondary to acute respiratory distress syndrome(ARDS).Based on the limited data available,there have been different opinions about the respiratory mechanics of the ARDS caused by coronavirus disease 2019(COVID-19).Our article provides an insight into COVID-19 pathophysiology and how it differs from typical ARDS.Based on these differences,our article explains the different approach to ventilation in COVID-19 ARDS compared to typical ARDS.We critically analyze the role of positive end-expiratory pressure(PEEP)and proning in the ICU patients.Through the limited data and clinical experience are available,we believe that early proning in COVID-19 patients improves oxygenation and optimal PEEP should be titrated based on individual lung compliance.

Sandwich Rolling over Method in Patients with Prone Position Ventilation

Background: Prone positioning is nowadays considered as one of the most effective strategies for patients with severe acute respiratory distress syndrome (ARDS). Prone position ventilation can lead to some severe complications. Effectively implement prone ventilation and reduce the incidence of complications become an important problem for clinical medical staff. Aims: To investigate whether the Sandwich rolling over method was convenient for clinical implementation and can reduce complications. Design: This is a single-center, retrospective, observational study. Results: The mean pronation cycles per patient were 6.11 ± 4.40. The mean time spent in prone position for each cycle was 10.05 ± 4.42 hours. Two patients developed a pressure sore and the positions were cheek, auricle and chest. The mean time it took from preparation to cover the patient with the quilt was 10.56 ± 4.35 minutes. Conclusions: This retrospective study has shown that under the close cooperation and supervision of the team, the implementation efficiency of prone position ventilation can be improved and the occurrence of complications can be reduced.

Effects of positive end-expiratory pressure on intracranial pressure,cerebral perfusion pressure,and brain oxygenation in acute brain injury:Friend or foe?A scoping review

Background Patients with acute brain injury(ABI)are a peculiar population because ABI does not only affect the brain but also other organs such as the lungs,as theorized in brain–lung crosstalk models.ABI patients often require mechanical ventilation(MV)to avoid the complications of impaired respiratory function that can follow ABI;MV should be settled with meticulousness owing to its effects on the intracranial compartment,especially regarding positive end-expiratory pressure(PEEP).This scoping review aimed to(1)describe the physiological basis and mechanisms related to the effects of PEEP in ABI;(2)examine how clinical research is conducted on this topic;(3)identify methods for setting PEEP in ABI;and(4)investigate the impact of the application of PEEP in ABI on the outcome.Methods The five-stage paradigm devised by Peters et al.and expanded by Arksey and O'Malley,Levac et al.,and the Joanna Briggs Institute was used for methodology.We also adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses(PRISMA)extension criteria.Inclusion criteria:we compiled all scientific data from peer-reviewed journals and studies that discussed the application of PEEP and its impact on intracranial pressure,cerebral perfusion pressure,and brain oxygenation in adult patients with ABI.Exclusion criteria:studies that only examined a pediatric patient group(those under the age of 18),experiments conducted solely on animals;studies without intracranial pressure and/or cerebral perfusion pressure determinations,and studies with incomplete information.Two authors searched and screened for inclusion in papers published up to July 2023 using the PubMed-indexed online database.Data were presented in narrative and tubular form.Results The initial search yielded 330 references on the application of PEEP in ABI,of which 36 met our inclusion criteria.PEEP has recognized beneficial effects on gas exchange,but it produces hemodynamic changes that should be predicted to avoid undesired consequences on cerebral blood flow and intracranial pressure.Moreover,the elastic properties of the lungs influence the transmission of the forces applied by MV over the brain so they should be taken into consideration.Currently,there are no specific tools that can predict the effect of PEEP on the brain,but there is an established need for a comprehensive monitoring approach for these patients,acknowledging the etiology of ABI and the measurable variables to personalize MV.Conclusion PEEP can be safely used in patients with ABI to improve gas exchange keeping in mind its potentially harmful effects,which can be predicted with adequate monitoring supported by bedside non-invasive neuromonitoring tools.

Effectiveness and safety of noninvasive positive-pressure ventilation for severe hypercapnic encephalopathy due to acute exacerbation of chronic obstructive pulmonary disease:a prospective case-control study

Background Although severe encephalopathy has been proposed as a possible contraindication to the use of noninvasive positive-pressure ventilation （NPPV）, increasing clinical reports showed it was effective in patients with impaired consciousness and even coma secondary to acute respiratory failure, especially hypercapnic acute respiratory failure （HARF）. To further evaluate the effectiveness and safety of NPPV for severe hypercapnic encephalopathy, a prospective case-control study was conducted at a university respiratory intensive care unit （RICU） in patients with acute exacerbation of chronic obstructive pulmonary disease （AECOPD） during the past 3 years. Methods Forty-three of 68 consecutive AECOPD patients requiring ventilatory support for HARF were divided into 2 groups, which were carefully matched for age, sex, COPD course, tobacco use and previous hospitalization history, according to the severity of encephalopathy, 22 patients with Glasgow coma scale （GCS） 〈10 served as group A and 21 with GCS 〉10 as group B. Results Compared with group B, group A had a higher level of baseline arterial partial CO2 pressure （（102±27） mmHg vs （74±17） mmHg, P〈0.01）, lower levels of GCS （7.5±1.9 vs 12.2±1.8, P〈0.01）, arterial pH value （7.18±0.06 vs 7.28±0.07, P〈0.01） and partial 02 pressure/fraction of inspired 02 ratio （168±39 vs 189±33, P〈0.05）. The NPPV success rate and hospital mortality were 73% （16/22） and 14% （3/22） respectively in group A, which were comparable to those in group B （68% （15/21） and 14% （3/21） respectively, all P〉0.05）, but group A needed an average of 7 cmH20 higher of maximal pressure support during NPPV, and 4, 4 and 7 days longer of NPPV time, RICU stay and hospital stay respectively than group B （P〈0.05 or P〈0.01）. NPPV therapy failed in 12 patients （6 in each group） because of excessive airway secretions （7 patients）, hemodynamic instability （2）, worsening of dyspnea and deterioration of gas exchange （2）, and gastric content aspiration （1）. Conclusions Selected patients with severe hypercapnic encephalopathy secondary to HARF can be treated as effectively and safely with NPPV as awake patients with HARF due to AECOPD; a trial of NPPV should be instituted to reduce the need of endotracheal intubation in patients with severe hypercapnic encephalopathy who are otherwise good candidates for NPPV due to AECOPD.

Effect of noninvasive, positive pressure ventilation on patients with severe, stable chronic obstructive pulmonary disease： a meta-analysis

Background This meta-analysis evaluated the effect of noninvasive, positive pressure ventilation on severe, stable chronic obstructive pulmonary disease （COPD）. Methods PUBMED, CNKI, Wanfang, EMBASE and the Cochrane trials databases were searched. Randomized controlled trials of patients with severe, stable COPD and receiving noninvasive positive pressure ventilation, compared with sham ventilation or no ventilation, were reviewed. The mortality, physiological and health related parameters were pooled to yield odds ratio （OR）, weighted mean differences or standardized mean differences （SMD）, with 95% confidence interval （CI）. Results Eight parallel and three crossover randomized controlled trials met the inclusion criteria. Pooled analysis for parallel, randomized controlled trials showed noninvasive positive pressure ventilation： （1） Did not affect the 12- or 24-month mortality （OR 0.82, 95% Ch 0.48 to 1.41）; （2） Improved the arterial carbon dioxide tension （SMD -0.88, 95% Ch -1.43 to -0.34）; （3） Did not improve forced expiratory volume in one second （SMD 0.20, 95% CI： -0.06 to 0.46）, maximal inspiratory pressure （SMD 0.01, 95% Ch -0.28 to 0.29） or 6-minute walk distance （SMD 0.17, 95% Ch -0.16 to 0.50）; （4） Subgroup analysis showed noninvasive positive pressure ventilation improved the arterial carbon dioxide tension in hypercapnic patients. Pooled analysis for crossover randomized controlled trials did not show improvement in arterial blood gas or forced expiratory volume in one second with noninvasive positive pressure ventilation. Conclusions Noninvasive positive pressure ventilation improves the arterial carbon dioxide tension but does not improve the mortality, pulmonary function, or exercise tolerance and should be cautiously used in severe stable chronic obstructive pulmonary disease.

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.