Noninvasive Mechanical Ventilation In Patients Research Articles

Benefits of dexmedetomidine during noninvasive mechanical ventilation in major abdominal surgery patients with postoperative respiratory failure.

The efficacy of non-invasive mechanical ventilation (NIMV) on the postoperative ARF is conflicting and the failure rate of NIMV in this patient population is high. In our study, we hypothesized that the use of dexmedetomidine during NIMV in major abdominal surgical patients can reduce NIMV failure without significant side affect. Medical records of patients who underwent major abdominal surgery, admitted to our general surgery intensive care unit (ICU), developed postoperative ARF, received NIMV (with oro-nasal mask) and dexmedetomidine infusion were enrolled in this study. The infusion rate was adjusted to maintain a target sedation level of a Richmond Agitation-Sedation Scale (RASS) (-2)-(-3). The sedation was stopped when NIMV was discontinued. A total of 60 patients, 42 (70.0%) male, and 18 (30.0%) female, with a mean age of 68 ± 11 years were included in the study. The mean APACHE II score was 20 ± 6. Dexmedetomidine was infused for a median of 25 h (loading dose of 0.2 mcg/kg for 10 min, maintained at 0.2-0.7 mcg/kg/h, titrated every 30 min). RASS score of all study group significantly improved at the 2 h of dexmedetomidine initiation (+3 vs. -2, p = 0.01). A targeted sedation level was achieved in 92.5% of patients. Six (10.0%) patients developed bradycardia and 5 (8.3%) patients had hypotension. The mean NIMV application time was 23.4 ± 6.1 h. Seven (11.6%) patients experienced NIMV failure, all due to worsening pulmonary conditions, and required intubation and invasive ventilation. Fifty-three (88.3%) patients were successfully weaned from NIMV with dexmedetomidine sedation and discharged from ICU. The duration of NIMV application and ICU stay was shorter in NIMV succeded group (21.4 ± 3.2 vs. 29.9 ± 6.4; p = 0.012). Our study suggests that dexmedetomidine demonstrates effective sedation in patients with postoperative ARF during NIMV application after abdominal surgery. Dexmedetomidine can be considered safe and capable of improving NIMV success.

Respiratory alkalosis in the acute hypoxemic patient during non-invasive mechanical ventilation: troubleshooting and prognostic relevance

Respiratory alkalosis is one of the four basic disturbances to the acid-base equilibrium. Persistent primary respiratory alkalosis during non-invasive mechanical ventilation in patients with hypoxemic respiratory failure could be a risk factor for NIV failure. A 69-year-old man with acute hypoxemic respiratory failure caused by severe COVID-19 pneumonia demonstrated progressive worsening of gas exchange and clinical conditions. Despite a positive response to noninvasive mechanical ventilation, a therapeutic increase in respiratory support was required.

The use of non-invasive mechanical ventilation in patients with COVID-19: an integrative review

The use of non-invasive mechanical ventilation in patients with COVID-19: an integrative review

Comparison of high flow oxygen therapy versus noninvasive mechanical ventilation for successful weaning from invasive ventilation in children: An observational study.

Post-extubation respiratory failure is associated with a poor prognosis due to increased ventilator-associated pneumonia, and longer length of stay in the ICU and hospital. In this study, we aimed to evaluate the efficacy of high-flow nasal cannula (HFNC) and noninvasive mechanical ventilation (NIMV) on extubation success in children. A total of 48 patients, aged between 1 month and 18 years, who were weaned to either NIMV or HFNC were included. Patients who had tracheostomy or were not weaned and underwent unplanned extubation were excluded. Age, gender, anthropometric parameters, Pediatric Risk of Mortality and Pediatric Logistic Organ Dysfunction scores, oxygenation index, mechanical ventilation length of stay (LOS), HFNC/NIMV LOS, Modified Downes-Silverman score (MDS), and venous blood gas parameters, pediatric intensive care unit (PICU) LOS were recorded. 24 patients were extubated to NIMV, and 24 patients to HFNC. HFNC LOS and NIMV LOS were similar (P = .621). The failure rates at the 48th hour of HFNC and NIMV were 33% (n = 8), and 33% respectively (n = 8) (P = 1.0). PICU LOS and mortality rate was also similar (P = .06, P = .312 respectively). MDS decreased significantly in both groups (P < .001, P = .02 respectively). Changes in blood gas parameters and MDS within the first 48-hour of device application were similar between the 2 groups. HFNC is not inferior to NIMV in patients with extubation difficulty or those expected to have such difficulty in terms of treatment success, PICU LOS, and mortality. Therefore, HFNC appears to be a weaning technique alternative to NIMV after extubation.

Efficacy Analysis of High-flow Nasal Oxygen Therapy in Patients Accepting Single-port Video-assisted Thoracoscopic Lobectomy

背景与目的部分胸外科患者术后拔除气管插管后并发低氧血症，常表现为Ⅰ型呼吸衰竭，改善低氧血症是促进患者术后康复的重要因素之一。本研究通过比较经鼻高流量湿化氧疗（high-flow nasal oxygen therapy, HFNO）、无创辅助通气（noninvasive mechanical ventilation, NIMV）及鼻导管吸氧（nasal oxygen breath, NOB）在单孔胸腔镜下肺叶切除术后并发低氧血症患者中的应用，探讨不同吸氧方式的优缺点，进一步探究HFNO在该类患者中的治疗效果。方法选取2021年6月-2022年3月在苏州大学附属第二医院接受单孔胸腔镜下肺叶切除术后并发低氧血症的患者180例，随机分为三组（n=60），分别采用HFNO、NIMV及NOB治疗。观察各组患者使用前、使用1 h、使用6 h-12 h及停止使用后的动脉血气分析结果、患者舒适度以及并发症发生率，并使用SPSS 25.0软件进行统计分析，P < 0.05为差异有统计学意义。结果对于单孔胸腔镜下肺叶切除术后并发低氧血症的患者，HFNO的治疗效果不逊于NIMV（P=0.333），相较于NOB，HFNO与NIMV均可较快提升患者的氧合指数（partial pressure of oxygen/fraction of inspiration O2, PaO2/FiO2）（P < 0.001）。除此之外，HFNO在患者使用舒适度、住院时间方面表现出绝对优势（P < 0.001, P=0.004），术后并发症较其他两组略有降低（P=0.232），但对于术后低氧血症并发动脉血二氧化碳分压（partial pressure of carbon dioxide, PaCO2）升高的患者，HFNO的治疗效果仍稍逊色于NIMV。结论对于单孔胸腔镜下肺叶切除术后并发低氧血症的患者，HFNO可作为首选治疗方式；但对于术后低氧血症伴随PaCO2升高的患者，仍推荐使用NIMV改善氧合。

Comparison of invasive intubation and noninvasive mechanical ventilation in patients with chronic obstructive pulmonary disease and obstructive sleep apnoea syndrome.

ObjectiveThe concurrence of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnoea syndrome (OSAS) is defined as overlap syndrome (OS), but investigations into predictors of OS in patients with COPD remain limited. Here, potential markers of OS in patients with COPD were investigated, and results of intubation were compared between patients with COPD only or OS.MethodsThis retrospective study included patients with COPD who were divided according to OS diagnosis: COPD only (COPD group) or OS (OS group).ResultsAmong 206 patients with COPD, 120 were diagnosed with OS. Mean body mass index (BMI) was significantly higher in the OS versus COPD group (28.95 ± 2.96 versus 23.84 ± 4.06, respectively). Receiver operating characteristic curve analyses revealed that BMI was associated with OS (area under the curve, 0.835). The rate of invasive intubation within 48 h was lower in the OS versus COPD group (9.2% versus 20.9%, respectively), and the duration of noninvasive ventilation was longer in the OS versus COPD group.ConclusionsBMI may be a predictor of OS in patients with COPD. The duration of noninvasive ventilation was longer in patients with OS than in patients with COPD alone.

High-flow nasal oxygen therapy versus conventional oxygen therapy and non-invasive mechanical ventilation in patients with acute respiratory failure and post-mechanical ventilation

BackgroundOxygen therapy is essential in the management of patients with respiratory problem, including after endotracheal extubation. Conventional oxygen devices may be inadequate in patients requiring high inspiratory flow. HFNC has a growing place in the repertoire of respiratory therapies. The purpose of this study was to compare the efficiency, tolerability, and outcome of HFNC in patients with respiratory failure and post-mechanical ventilation patients in comparison to NIV and conventional oxygen devices.ResultsIn case of respiratory failure patients, there was non-significant statistical difference between HFNC, conventional oxygen therapy and NIV, regarding the difference in ABGs, vital data, and dyspnea scores, at successive time points, except for PO2 after 30 min in patients received NIV, which was significantly higher. There was non-significant statistical difference between the three mentioned modalities of oxygen therapy regarding comfort and clinical outcome.In case of post-extubation patients, there was non-significant statistical difference between the HFNC and conventional oxygen therapy regarding clinical parameters, comfort and outcome.ConclusionsHFNC is comparable to conventional oxygen therapy in respiratory failure and post-extubation patients. HFNC is comparable to NIV in respiratory failure patients.

Penggunaan Ventilasi Mekanik non Invansif Untuk Mengatasi Kegagalan Pernafasan pada Pasien dengan Edema Pulmo Akut Kardiogenik

Background: Cardiogenic Pulmo edema can cause a heterogeneous syndrome with a mortality rate of up to 9.5% (Aliberti et all., 2018).Objective: The purpose of this paper was to explain how effective the use of non-invasive mechanical ventilation in patients with acute pulmonary edema with respiratory failure.&#x0D; Methods: The literature review was compiled by synthesizing and comparing various relevant scientific articles from the literature search results using the online database of Proquest and Clinicalkey Elsevier that have significance related to the management of acute cardiogenic pulmo edema.&#x0D; Result: Compared with conservative therapy, noninvasive mechanical ventilation has been shown more effective in improving oxygenation in patients with acute cardiogenic pulmo edema Non-invasive ventilation can reduce dyspnea, acidosis and hypercapnea faster than standard oxygen therapy. Studies show that compared to endotracheal intubation, non-invasive mechanical ventilation is associated with a lower risk of nosocomial infection, lower antibiotic use, shorter length of stay in intensive care units and lower mortality. Study found that there were no differences betwen the two setting of non-invasive mechanical ventilation used, Bilevel positive Airway Pressure (BiPAP) and Continues positive Airway Pressure (CPAP) in patients outcomes. However, there are absolute and relative contraindications that must be considered, including the effectiveness of the therapy being insignificant when given too late&#x0D; Conclusion: Noninvasive mechanical ventilation can be considered as the first choice in the management of acute cardiogenic pulmonary edema because of its high clinical effectiveness representing a rescue action for patients not improving with conventional oxygen therapy.

What is the right moment for noninvasive ventilation in amyotrophic lateral sclerosis?

The most common cause of death in patients with amyotrophic lateral sclerosis (ALS) is respiratory failure, often in the period of 2-5 years, with a small percentage of patients surviving up to 10 years or more. The aim of the study was to evaluate the significance of pulmonary function tests in prediction of mortality and definition of indications for noninvasive mechanical ventilation (NIMV). This retrospective-prospective study was performed at the Clinic of Pulmonology, Clinical Centre of Serbia in the period from January 2015 to December 2017. Patients with diagnosis of ALS established according to El Escorial criteria were included. The study included 76 patients with ALS, 50 (65.85%) with spinal and 26 (34.2%) with bulbar form of disease. Forced vital capacity (FVC) and forced expiratory volume in 1 s (FEV1) were higher in spinal form of ALS, and the difference was statistically significant when compared to bulbar form. Form of disease, FVC < 70%, maximum inspiratory pressure (PImax) < 50 and maximum expiratory pressure (PEmax) < 50 were significant factors for survival. The patients with bulbar form of disease had 2.174 (95.0% CI: 1.261-3.747) higher risk for death. Our study points to the significance of timely application and early start of NIMV in patients with ALS as an important approach to defer functional impairment, which would mean that the criteria, in our country, for application of these devices must be changed, not only regarding the value of current functional diagnostic tests used in everyday practice in patients with ALS but also in regard to the introduction of new diagnostic tests, such as sniff nasal inspiratory pressure and/or polysomnographic testing.

Ventilación mecánica no invasiva en pacientes con traumatismo de tórax

Mechanical ventilation in patients with chest injury becomes a challenge due to physiological changes. Currently, chest injuries account for 10-15% of all traumas, and are responsible for 17-25% of all deaths caused by trauma. However, there is no clinical evidence to make recommendations for the use of any of the ventilation modes. The objective of this study is to demonstrate that non-invasive mechanical ventilation (NIMV) corrects hypoxaemia in chest trauma patients. Materials and methodsProspective descriptive, observational and analytical study was conducted on 19 patients with chest trauma managed with NIMV in the continuous positive airway pressure (CPAP) mode. The age of the patients was between 18 and 67 years. For those patients with criteria for NIMV, the protocol implemented was 4hours of NIMV in CPAP mode with full mask. The parameters included: A pressure support variable plus a positive end-expiratory pressure of 10cm H2O, and FiO2 at 50% for 4h of venturi mask at 50%. Arterial blood samples were taken one hour after NIMV withdrawal. Failure was defined if continued with venturi, returned to NIMV, or went on to invasive mechanical ventilation. ResultsThe study included 89.5% males, and all (100%) of the patients had a mean Revised Trauma Score of less than 11 on admission to the emergency department, as well as a mean Injury Severity Score of 19, a mean Thorax Trauma Severity Score of 10, as well as a mean base excess −2.0. The mean time of NIMV was 3.2 days. An improvement of PO2 and PaO2/FiO2 index (PAFI) was observed in relation to the use of NIMV in CPAP mode, as well as a relationship with the classification of thoracic trauma (TTSS), and the time of NIMV. With this study, it can be concluded that NIMV in patients with chest trauma reduces intubation time and reduces mortality, as well as improving hypoxaemia in this group of patients.

The Use of Dexmedetomidine During Non-Invasive Mechanical Ventilation in Patients with Post-operative Respiratory Failure

The Use of Dexmedetomidine During Non-Invasive Mechanical Ventilation in Patients with Post-operative Respiratory Failure

Predictors of Need for Non-Invasive Mechanical Ventilation in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Predictors of Need for Non-Invasive Mechanical Ventilation in Patients with Acute Exacerbation of Chronic Obstructive Pulmonary Disease

Role of noninvasive mechanical ventilation in patients with severe avian influenza A (H7N9) complicated with acute respiratory distress syndrome

Human infection with avian influenza A (H7N9) is an acute contagious respiratory disease. Acute respiratory distress syndrome (ARDS) is a common complication in patients with severe avian influenza A (H7N9), for whom mechanical ventilation (MV) is an important supportive method. A patient, suffered from severe avian influenza A (H7N9) and complicated with ARDS, was admitted to the Second Affiliated Hospital of Guizhou Medical University in January 2017. With very intensive care for oxygenation, respiration and consciousness, and monitoring, she was successfully cured by comprehensive managements, among which noninvasive mechanical ventilation (NIV) was the major respiratory support method. The result demonstrate that, in patients with conscious state, satisfied expectoration ability and relatively good cooperation, and with close observation of oxygenation and respiratory rate, NIV may be accepted as an effective method for patient with ARDS caused by severe avian influenza A (H7N9).

Observation on the effect of noninvasive mechanical ventilation in patients with chronic obstructive pulmonary disease with respiratory failure

Objective To analyze the therapeutic effect of noninvasive mechanical ventilation in chronic obstructive pulmonary disease (COPD) patients with respiratory failure. Methods Sixty patients with COPD respiratory failure were randomly divided into two groups.30 cases in the conventional treatment group used conventional comprehensive therapy.30 cases in the noninvasive mechanical ventilation group were given noninvasive mechanical ventilation based on conventional treatment.The total effective rate, time to correct the abnormal breathing, hospitalization time were compared between the two groups.Before and after treatment, the arterial blood gas analysis indicators and heart rate, respiratory rate, probability, mortality for ventilator ventilation were compared in the two groups. Results The total effective rate of the noninvasive mechanical ventilation group was 96.67%, which was higher than 73.33% of the conventional treatment group(χ2=6.405, P 0.05). After treatment, the frequency of PaCO2, PaO2, heart rate and respiratory rate in the conventional treatment group were (60.45±3.94)mmHg, (60.24±4.12)mmHg, (92.58±0.61)times/min, (22.45±3.14)times/min, respectively, which in the noninvasive mechanical ventilation group were (52.24±1.23)mmHg, (76.24±5.26)mmHg, (83.92±0.62)times/min, (17.26±2.23)times/min, respectively, the differences between the two groups were statistically significant(t=5.133, 3.734, 5.166, 6.360, all P<0.05). The invasive rate of invasive ventilator and mortality of noninvasive mechanical ventilation group were 3.33% and 0.00%, respectively, which were lower than 20.00%, 13.33% of the conventional treatment group (χ2=7.214, 6.247, all P<0.05). Conclusion Noninvasive mechanical ventilation is effective in treatment of patients with COPD respiratory failure, which can effectively improve the indicators of arterial blood gas and heart rate and respiratory rate, improve the prognosis of patients, improve the ventilation probability of invasive ventilator. Key words: Respiration, artificial; Pulmonary disease, chronic obstructive; Respiratory insufficiency

Can patients with moderate to severe acute respiratory failure from COPD be treated safely with noninvasive mechanical ventilation on the ward?

PurposeNoninvasive mechanical ventilation (NIMV) usage outside of intensive care unit is not recommended in patients with COPD for severe acute respiratory failure (ARF). We assessed the factors associated with failure of NIMV in patients with ARF and severe acidosis admitted to the emergency department and followed on respiratory ward.Patients and methodsThis is a retrospective observational cohort study conducted in a tertiary teaching hospital specialized in chest diseases and thoracic surgery between June 1, 2013 and May 31, 2014. COPD patients who were admitted to our emergency department due to ARF were included. Patients were grouped according to the severity of acidosis into two groups: group 1 (pH=7.20–7.25) and group 2 (pH=7.26–7.30).ResultsGroup 1 included 59 patients (mean age: 70±10 years, 30.5% female) and group 2 included 171 patients (mean age: 67±11 years, 28.7% female). On multivariable analysis, partial arterial oxygen pressure to the inspired fractionated oxygen (PaO2/FiO2) ratio <200, delta pH value <0.30, and pH value <7.31 on control arterial blood gas after NIMV in the emergency room and peak C-reactive protein were found to be the risk factors for NIMV failure in COPD patients with ARF in the ward.ConclusionNIMV is effective not only in mild respiratory failure but also with severe forms of COPD patients presenting with severe exacerbation. The determination of the failure criteria of NIMV and the expertise of the team is critical for treatment success.

Does the Body Mass Index Affect the Success of Noninvasive Mechanical Ventilation in Patients with Acute Hypercapnic Respiratory Failure?

Objective: Obesity has many negative effects on lung functions. It is not yet clear whether body mass index (BMI) affects the success of noninvasive mechanical ventilation (NIMV). The aim of this study was to investigate the differences in NIMV strategies, on the basis of BMI, in patients with acute hypercapnic respiratory failure and the effect of BMI on the success of NIMV. Methods: A total of 86 patients who had acute hypercapnic respiratory failure were enrolled consecutively. They were grouped according to BMI as follows: BMI 18.5 - 24.9kg/m 2 (normal); group 1, BMI 25 - 30kg/m2 (overweight); group 2, BMI>30kg/m2 (obese); group 3. Age, gender, duration of ICU stay, pressures of NIMV and Arterial Blood Gas (ABG) before, during and after the NIMV were recorded. Results: In total, 52 patients (60%) were male. The mean age of the patients was 70 ± 12 years. The success rates of NIMV in groups 1, 2 and 3 were 50%, 28% and 21%, respectively. The success rates were not significantly different between groups (p=0.79). In group 3, the respiratory rate was higher and pH was lower during the first hour compared to the other groups (p<0.05, p<0.05). PaCO 2 levels were higher in group 3 on the first day and at the end of NIMV treatment (p=0.04, p<0.05). Conclusion: NIMV strategies should be different in acute hypercapnic respiratory failure patients with a high BMI, and in these patients, clinical improvement requires a long duration.

Non-invasive mechanical ventilation in patients with diffuse interstitial lung diseases.

BackgroundTo evaluate noninvasive ventilation (NIV) in diffuse interstitial lung diseases (DILD) patients with acute respiratory failure (ARF) according to baseline radiological patterns and the etiology of ARF.MethodsIn a multicenter, observational, retrospective study, consecutive DILD patients undergoing NIV because of an episode of ARF were evaluated in six Italian high dependency units. Three groups of patients were identified based on the etiology of ARF: those with pneumonia (Group A), those with acute exacerbation of fibrosis, (Group B) and those with other triggers (Group C). Clinical failure was defined as any among in-hospital mortality, endotracheal intubation and extra-corporeal membrane oxygenation use.ResultsAmong the 60 patients enrolled (63% males; median age: 71 years), pneumonia (42%) and acute exacerbation of fibrosis (39%) were the two most frequent causes of ARF. A significant increase of PaO2/FiO2 ratio during NIV treatment was detected in Group A (p = 0.010), but not in Group B. No significant difference in PaO2/FiO2 ratio, PaCO2 and pH values during NIV treatment was detected in patients with a radiological pattern of usual interstitial pneumonia (UIP) and non-specific interstitial pneumonia (NSIP). 22 patients (37%) suffered for a clinical failure. No significant differences in the study outcome were detected in Group A vs. Group B, as well as among patients with a radiological pattern of UIP vs. NSIP.ConclusionsNIV treatment should be individualized in DILD patients with ARF according to the etiology, but not the baseline radiological pattern, in order to improve oxygenation.

Akut hiperkapnik solunum yetmezliğinde noninvaziv mekanik ventilasyonun geç başarısızlığı için risk faktörleri

Non-invasive mechanical ventilation provides early improvement in most of the patients with acute hypercapnic respiratory failure. The aim of our study was to determine the risk factors for late failure of non-invasive mechanical ventilation in patients with acute hypercapnic respiratory failure. Ninety three patients were prospectively evaluated. Non-invasive mechanical ventilation was accepted to be successful if the patient was discharged from the hospital without the need for intubation (group 1) and to be late failure if a deterioration occurred after an initial improvement of blood gases tension and general conditions (group 2). Non-invasive mechanical ventilation was successful in 62 (66.7%) patients. In 25 (26.9%) patients a late failure was observed. There was no difference between groups 1 and 2 in terms of pretreatment pH, PaCO2 and PaO2/FiO2. However, serum C-reactive protein level, Acute Physiology and Chronic Health Evaluation II (APACHE II) score and frequency of bronchiectasis and pneumonia were significantly higher and serum albumin level, Glasgow Coma Score, cough strength and compliance to non-invasive mechanical ventilation were significantly lower in group 2. The pretreatment high APACHE II Score and C-reactive protein level, low Glasgow Coma Score, albumin level, cough strength, bad compliance to non-invasive mechanical ventilation, the presence of bronchiectasis and pneumonia and absence of significance improvement in PaO2/FiO2 after treatment were determined as risk factors for non-invasive mechanical ventilation late failure.

Efficacy of noninvasive volume targeted ventilation in patients with chronic respiratory failure due to kyphoscoliosis.

Severe kyphoscoliosis can cause chronic respiratory failure. Noninvasive mechanical ventilation (NIMV) is a new optional treatment for such patients. The aim of this study was to evaluate the effectiveness of average volume-assured pressure support (AVAPS) NIMV in patients with kyphoscoliotic chronic respiratory failure. The study was performed in 12 patients (mean age 49±11 years and body mass index 27.5±7.9 kg/m2) with advanced kyphoscoliosis complicated by severe respiratory failure (PaO2 6.68±0.34 kPa, SaO2 81.7±3.1%, PaCO2 9.51±1.08 kPa) treated by the NIMV. The short-term, after 5 days, and long-term, after 1 year of home treatment, efficacy of NIMV was evaluated. We found a significant improvement of diurnal PaO2 and PaCO2 on the 5th day of NIMV (an increase of 1.4±0.3 kPa and a decrease of 1.8±0.8 kPa, respectively; p<0.05) and after one year NIMV (an increase of 2.07±0.46 kPa and a decrease of 2.68±0.85 kPa, respectively; p<0.05). There was a significant increase of mean blood oxygen saturation during sleep on the 5th day (86.2±3.2%) and after 1 year of treatment (89.4±2.1%) compared with the baseline level (83.2±3.2%). The forced vital capacity also increased after 1 year (1,024±258 ml vs. the baseline 908±267 ml; p<0.05). The NIMV was well tolerated and no patient discontinued the treatment during the observation period. We conclude that AVAPS NIMV is an effective treatment option in kyphoscoliotic patients with chronic respiratory failure, resulting in a prompt and long-term improvement of daytime and nocturnal blood gas exchange.

Volutrauma and Regional Ventilation Revisited

Volutrauma and Regional Ventilation Revisited