Neurocritical care (NCC) is not only generally guided by principles of general intensive care, but also directed by specific goals and methods. This review summarizes the common pulmonary diseases and pathophysiology affecting NCC patients and the progress made in strategies of respiratory support in NCC. This review highlights the possible interactions and pathways that have been revealed between neurological injuries and respiratory diseases, including the catecholamine pathway, systemic inflammatory reactions, adrenergic hypersensitivity, and dopaminergic signaling. Pulmonary complications of neurocritical patients include pneumonia, neurological pulmonary edema, and respiratory distress. Specific aspects of respiratory management include prioritizing the protection of the brain, and the goal of respiratory management is to avoid inappropriate blood gas composition levels and intracranial hypertension. Compared with the traditional mode of protective mechanical ventilation with low tidal volume (Vt), high positive end-expiratory pressure (PEEP), and recruitment maneuvers, low PEEP might yield a potential benefit in closing and protecting the lung tissue. Multimodal neuromonitoring can ensure the safety of respiratory maneuvers in clinical and scientific practice. Future studies are required to develop guidelines for respiratory management in NCC.
Humans ; Lung ; Lung Diseases/etiology* ; Positive-Pressure Respiration/methods* ; Respiration, Artificial/adverse effects* ; Tidal Volume

Breathing pattern parameters refer to the characteristic pattern parameters of respiratory movements, including the breathing amplitude and cycle, chest and abdomen contribution, coordination, etc. It is of great importance to analyze the breathing pattern parameters quantificationally when exploring the pathophysiological variations of breathing and providing instructions on pulmonary rehabilitation training. Our study provided detailed method to quantify breathing pattern parameters including respiratory rate, inspiratory time, expiratory time, inspiratory time proportion, tidal volume, chest respiratory contribution ratio, thoracoabdominal phase difference and peak inspiratory flow. We also brought in "respiratory signal quality index" to deal with the quality evaluation and quantification analysis of long-term thoracic-abdominal respiratory movement signal recorded, and proposed the way of analyzing the variance of breathing pattern parameters. On this basis, we collected chest and abdomen respiratory movement signals in 23 chronic obstructive pulmonary disease (COPD) patients and 22 normal pulmonary function subjects under spontaneous state in a 15 minute-interval using portable cardio-pulmonary monitoring system. We then quantified subjects' breathing pattern parameters and variability. The results showed great difference between the COPD patients and the controls in terms of respiratory rate, inspiratory time, expiratory time, thoracoabdominal phase difference and peak inspiratory flow. COPD patients also showed greater variance of breathing pattern parameters than the controls, and unsynchronized thoracic-abdominal movements were even observed among several patients. Therefore, the quantification and analyzing method of breathing pattern parameters based on the portable cardiopulmonary parameters monitoring system might assist the diagnosis and assessment of respiratory system diseases and hopefully provide new parameters and indexes for monitoring the physical status of patients with cardiopulmonary disease.
Humans ; Lung ; Pulmonary Disease, Chronic Obstructive ; Respiration ; Tidal Volume ; Wearable Electronic Devices

The high frequency oscillatory ventilation (HFOV) is characterized with low tidal volume and low mean airway pressure, and can well support the breathing of the patients with respiratory diseases. Since the HFOV was proposed, it has been widely concerned by medical and scientific researchers. About the HFOV, this paper discussed its current research status and prospected its future development in technologies. The research status of ventilation model, mechanisms and ventilation mode were introduced in detail. In the next years, the technologies in developing HFOV will be focused on: to develop the branched high-order nonlinear or volume-depended resistance-inertance-compliance (RIC) ventilation model, to fully understand the mechanisms of HFOV and to achieve the noninvasive HFOV. The development in technologies of HFOV will be beneficial to the patients with respiratory diseases who failed with conventional mechanical ventilation as one of considerable ventilation methods.
High-Frequency Ventilation ; Humans ; Lung ; Respiration, Artificial ; Respiratory Distress Syndrome ; Tidal Volume

OBJECTIVE: To study the characteristics of pulmonary function in children with pertussis-like coughing caused by different pathogen infections. METHODS: The data on etiology and tidal breathing pulmonary function were collected from 95 hospitalized infants and young children with pertussis-like coughing. The tidal breathing pulmonary function was compared between these children and 67 healthy children. According to the type of pathogen, the children with pertussis-like coughing were classified to 6 groups: pertussis (n=17), viral infection (n=23), tuberculosis infection (n=6), Mycoplasma infection (n=9), other bacterial infection (n=8), and unknown pathogen (n=32). RESULTS: Among the 95 children with pertussis-like coughing, 15 (16%) had mild obstructive ventilatory dysfunction, 30 (32%) had moderate obstructive ventilatory dysfunction, and 22 (23%) had severe obstructive ventilatory dysfunction. Compared with the normal control group, the children with pertussis-like coughing had significant reductions in inspiratory-to-expiratory time ratio, ratio of time to peak tidal expiratory flow to total expiratory time (tPF%tE), and ratio of volume to peak tidal expiratory flow to total expiratory volume (vPF%vE) (P<0.05). The tuberculosis infection and Mycoplasma infection groups had a significantly lower tidal volume than the normal control group (P<0.05). All pathogen infection groups except the tuberculosis infection group had significantly lower tPF%tE and vPF%vE than the normal control group (P<0.05). The pertussis group had significantly lower tPF%tE and vPF%vE than the other infection groups (P<0.05). CONCLUSIONS Most of children with pertussis-like coughing have abnormal pulmonary functions. The children with Bordetella pertussis infection have the most severe pulmonary function impairment. Tidal breathing pulmonary function test may provide a reference for pathogen analysis of children with pertussis-like coughing.
Child ; Child, Preschool ; Humans ; Infant ; Lung ; Respiration ; Respiratory Function Tests ; Tidal Volume ; Whooping Cough

OBJECTIVE: To investigate the relationship between different tidal volume (VT) mechanical ventilation (MV) and autophagy and mitochondrial damage in rats. METHODS: A total of 120 clean-grade male Sprague-Dawley (SD) rats were divided into five groups (n = 24) by random number table method, and then given 0 (spontaneous breathing), 10, 20, 30, 40 mL/kg VT for MV. The rats in each group were subdivided into four subgroups of 1, 2, 3, and 4 hours according to ventilation time, with 6 rats in each subgroup. The lung tissue and bronchoalveolar lavage fluid (BALF) were harvested, and alveolar macrophages (AMs) and type II alveolar epithelial cells (AEC II) were cultured in vitro. The mRNA and protein expressions of autophagy-associated protein microtubule-associated protein 1 light chain 3B-II (LC3B-II) and autophagy-related genes Beclin1 and p62 were determined by reverse transcription-polymerase chain reaction (RT-PCR) or Western Blot. Lung autophagosome formation was observed under transmission electron microscope. The levels of adenosine triphosphate (ATP), reactive oxygen species (ROS) and mitochondrial membrane potential (MMP) in lung tissue were determined for assessing mitochondrial damage. RESULTS: There were no significant differences in the mRNA and protein expressions of LC3B-II, p62 and Beclin1 at 1 hour after ventilation among the groups. With the prolonged ventilation time, the mRNA and protein expressions of LC3B-II, p62 and Beclin1 in MV groups were increased gradually, peaked at 2-3 hours, and they were increased significantly in 30 mL/kg VT group as compared with those in spontaneous respiration group with statistical significances [ventilation for 2 hours: LC3B-II mRNA (2^-ΔΔCt) was 2.44±0.24 vs. 1.12±0.04, LC3B-II/LC3B-I was 1.42±0.16 vs. 0.57±0.03, p62 mRNA (2^-ΔΔCt) was 2.96±0.14 vs. 1.14±0.02, Beclin1 mRNA (2^-ΔΔCt) was 2.80±0.13 vs. 1.14±0.02; ventilation for 3 hours: p62/β-actin was 1.14±0.15 vs. 0.55±0.04, Beclin1/β-actin was 1.27±0.06 vs. 0.87±0.04, all P < 0.05]. Autophagosomes and autolysosomes were found in AEC II after ventilation for 2 hours at 30 mL/kg VT by transmission electron microscopy, but not in AEC I. Compared with spontaneous breathing group, ATP synthesis in AMs was significantly decreased at 2 hours of ventilation in 30 mL/kg VT group (A value: 0.82±0.05 vs. 1.00±0.00, P < 0.05), ROS accumulate in AMs and AEC II were significantly increased [ROS in AMs: (33.83±4.00)% vs. (6.90±0.62)%, ROS in AEC II: (80.68±0.90)% vs. (2.16±0.19)%, both P < 0.05]. With the increase in VT and the prolongation of ventilation time, ATP and ROS levels in AMs and AEC II were gradually decreased, the ATP (A value) in AMs at 4 hours of ventilation in 40 mL/kg VT group was 0.41±0.05, the ROS in AMs was (12.95±0.88)%, and the ROS in AEC II was (40.43±2.29)%. With the increase in VT and the prolongation of ventilation time, MMP levels were gradually increased, the MMP (green/red fluorescence intensity ratio) in AMs at 2 hours of ventilation in 30 mL/kg VT group was 1.11±0.17, the MMP in AEC II was 0.96±0.04, and the MMP (green/red fluorescence intensity ratio) at 4 hours of ventilation in 40 mL/kg VT group was 0.51±0.07 and 0.49±0.06, respectively. CONCLUSIONS The MV with high VT could induce autophagy activation and mitochondrial damage in lung tissue of rats, and the longer the ventilation time, the more obvious autophagy in the lung.
Animals ; Autophagy/physiology* ; Male ; Mitochondria/pathology* ; Rats ; Rats, Sprague-Dawley ; Respiration, Artificial/adverse effects* ; Tidal Volume ; Time Factors ; Ventilator-Induced Lung Injury

To explore the relationship between paediatric early warning score (PEWS) and the occurrence of mechanical ventilation complications in children with acute respiratory distress syndrome (ARDS).
 Methods: A total of 110 children with ARDS diagnosed in First Affiliated Hospital of Hebei North University, who underwent mechanical ventilation, were selected. The baseline data, blood gas analysis index, laboratory test index, ventilator parameters, pediatric critical illness score (PCIS) and PEWS in the children were recorded. With reference to ventilatory treatment results, the children with ventilator-associated complications were included in the trial group (n=20), while the patients with good cohort status were included in the control group (n=40) according to the nested case-control study. Independent sample t-test and multivariate logistic regression analysis were used to analyze the factors affecting the occurrence of complications after ventilatory treatment.
 Results: There were statistically significant differences in multiple organ dysfunction syndrome (MODS), partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2), partial pressure of carbon dioxide (PaCO2), serum creatinine (SCr), albumin (ALB), blood urea nitrogen (BUN), mechanical ventilation time, mean article pressure (MAP), tidal volume (VT), positive end-expiratory pressure (PEEP), PCIS, PEWS between the control group and the experimental group (all P<0.05). Multivariate logistic regression analysis showed that MODS, PaO2/FiO2, PaCO2, VT, PEEP and PEWS had influence on complications after mechanical ventilation in children with ARDS (all P<0.05).
 Conclusion: The MODS, PaO2/FiO2, PaCO2, VT, PEEP, and PEWS exert effects on complications after mechanical ventilation in children with ARDS. PEWS combined with other indicators can assess the risk of complications in children with ARDS after mechanical ventilation.
Case-Control Studies ; Child ; Humans ; Positive-Pressure Respiration ; Respiration, Artificial ; Respiratory Distress Syndrome, Adult ; Tidal Volume

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

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

This study was to design a chronic obstructive pulmonary disease (COPD) screening equipment, based on the dual-differential pressure throttling technique. The technique combined a wide range, but low-resolution ratio sensor and a narrow range, but high-resolution ratio one. It can accurately detect the indexes of forced vital capacity (FVC), forced expiratory volume in one second (FEV), one second rate(FEV/FVC (%)), and achieve them in a low-cost way. The new designed machine will be compared with a British machine, named ML-3500. The correlations of FVC and FEV between new machine and ML-3500 were 0.998 and 0.999, respectively. The P values of paired test of these two indexes were over 0.05. Bland-Altman analysis of FVC, FEV and FEV/FVC (%) showed that more than 90% of the scatter points of the three parameters fell within the consistency interval. This machine can be used to accurately screen COPD and its low-cost would be advantage to promote in large population.
Forced Expiratory Volume ; Humans ; Pulmonary Disease, Chronic Obstructive ; diagnosis ; Reproducibility of Results ; Respiratory Function Tests ; economics ; instrumentation ; Tidal Volume ; Vital Capacity

OBJECTIVE: To investigate the role and mechanism of Ly6C^high monocyte in mice with ventilator-induced lung injury (VILI). METHODS: Forty-eight healthy male SPF C57BL/6 mice were divided into spontaneous breathing group (n = 8), normal tidal volume (VT) group (VT was 8 mL/kg, n = 8), and high VT group (VT was 20 mL/kg, n = 32). The mice in the high VT group were subdivided into 1, 2, 3 and 4 hours subgroups, with 8 mice in each subgroup. All mice underwent direct tracheal intubation, those in the spontaneous breathing group maintained spontaneous breathing, and those in the normal VT group and high VT group were mechanically ventilated with different VT. After ventilation for 4 hours, bronchoalveolar lavage fluid (BALF) was collected to determine total protein, and the levels of inflammatory factors including tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were determined by enzyme-linked immune sorbent assay (ELISA). The lung tissues were harvested to determine the wet/dry (W/D) ratio, and lung tissue injury was assessed in terms of lung histopathologic examination after hematoxylin-eosin (HE) staining under the light microscope. The protein expressions of monocyte chemotactic protein-1 (MCP-1) and CC-chemokine receptor 2 (CCR2) in lung tissues were determined by Western Blot. Flow cytometry was used to detect the proportion of Ly6C^high monocyte in lung tissue. RESULTS: The histopathology of lung tissue structures was normal in the spontaneous breathing group and the normal VT group. Inflammatory reaction began to appear at 2 hours of high VT ventilation, and inflammatory reaction was gradually aggravated with the time extension. Compared with the spontaneous breathing group, the total protein, TNF-α, and IL-1β levels in BALF, the lung W/D ratio and MCP-1 expression were increased from 2 hours of high VT ventilation [total protein in BALF (g/L): 1.05±0.13 vs. 0.58±0.11, TNF-α in BALF (ng/L): 116.86±16.14 vs. 38.27±8.00, IL-1β in BALF (ng/L): 178.98±10.41 vs. 117.56±23.40, lung W/D ratio: 5.76±0.27 vs. 4.98±0.39, MCP-1/GAPDH: 0.87±0.19 vs. 0.29±0.12, all P < 0.05], and CCR2 expression and the proportion of Ly6C^high monocyte was significantly increased from 3 hours of high VT ventilation [CCR2/GAPDH: 0.84±0.19 vs. 0.24±0.11, Ly6C^high monocyte proportion: (9.01±2.47)% vs. (1.06±0.35)%, both P < 0.05], and they all showed an increased tendency with the time extension. There was no significant difference in the parameters mentioned above among the spontaneous breathing group, normal VT group and high VT ventilation 1-hour group. CONCLUSIONS Ly6C^high monocytes are involved in VILI, which aggravate VILI by activating the MCP-1/CCR2 axis.
Animals ; Antigens, Ly/metabolism* ; Lung ; Male ; Mice ; Mice, Inbred C57BL ; Monocytes ; Rats ; Rats, Sprague-Dawley ; Tidal Volume ; Tumor Necrosis Factor-alpha ; Ventilator-Induced Lung Injury