机械通气领域目前有几大争论, 涉及在机械通气中基本的也是十分重要的问题, 复习和深入探讨这些问题, 对了解机械通气近年的研究进展, 指导机械通气的临床实践很有意义。
Objective To investigate the influence of different mechanical ventilation modes on inflammatory reaction among COPD patients with severe respiratory failure. Methods A total of 102 COPD patients with severe respiratory failure, admitted in Zhongshan Hospital between January 20007 and June 2012, were enrolled in this study. The subjects were divided into an ASV group receiving adaptive support ventilation, and a SIMV + PSV group received synchronized intermittent mandatory ventilation and pressure support ventilation, with 51 cases in each group. Breathing pattern, respiratory mechanics, hemodynamic parameters and seruminflammatory factors were examined among all patients. Results Tidal volume ( VT ) was significantly higher, and the control respiratory rate and ventilation time were significantly lower in the ASV group than those in the SIMV + PSV group ( P lt; 0.05) . Comparing with the SIMV + PSV group, obviously lower peak airway pressure ( Ppeak) ,mean airway pressure ( Pmean) and airway plateau pressure ( Pplat) were observed in the ASV group ( P lt; 0.05) . The patients in the ASV group had obviously lower levels of C-reactive protein, procalcitonin and α1 acid glycoprotein. Conclusion ASV ventilation mode may reduce the inflammatory reaction, facilitate spontaneously breathing and decrease mechanical ventilation time.
Objective To observe the effects of exogenous pulmonary surfactant (PS) on ventilation-induced lung injury (VILI) in rats, and to investigate its possible mechanisms. Methods A total of 40 Wistar rats were divided into 4 groups with randomized blocks method: control group, high tidal volume (HV) group, VILI group, and PS group, with 10 rats in each group. The control group was subjected to identical surgical procedure but was never ventilated. After 30 min of mechanical ventilation (MV) with Vt 45 ml/kg, the rats in HV group were killed immediately; rats in the VILI group were continually ventilated for up to 150 min with Vt 16 ml/kg; in the PS group, 100 mg/kg of PS administered intratracheally and with the same settings as VILI group. Mean artery pressure (MAP), blood gas analysis, lung wet to dry weight ratios (W/D), thorax-lung compliance, and cell counts in bronchoalveolar lavage fluid (BALF) were determined. Nuclear factor-κB(NF-κB) activity in lungs was measured by enzyme-linked immunosorbent assay (ELISA), interleukin-8(IL-8) in serum and BALF was determined by radioimmunoassay (RIA). Pathological examination of the lung was performed. Results Injurious ventilation significantly decreased MAP and PaO2/FiO2, but increased NF-κB activity and W/D. MAP and PaO2/FiO2 improved, but NF-κB activity, IL-8 in serum and BALF, and cell counts in BALF reduced significantly in PS group compared with those in VILI group. Histological studies showed reduced pulmonary edema and atelectasis in the PS group. Conclusion PS administered intratracheally can suppress the increased activity of NF-κB induced by VILI, exogenous PS can be used to treat VILI.
Objective To study the sedative effects and safety of dexmedetomidine and midazolamfor acute exacerbate of chronic obstructive pulmonary disease ( AECOPD) underwentmechanical ventilation.Methods 68 AECOPD patients underwentmechanical ventilation were enrolled and randomly divided into adexmedetomidine group ( n =34) and a midazolam group ( n = 34) by acute physiology and chronic healthevaluation Ⅱ ( APACHEⅡ) score. The patients in the dexmedetomidine group were given a loading dose( 1 μg/kg) and then maintained with 0. 2-0. 8 mg·kg- 1 ·h- 1 . The patients in the midazolam group weregiven a loading dose ( 0. 05 mg/kg) and then maintained with 0. 06-0. 2 mg· kg- 1 · h- 1 . Sedation levelwas assessed by Ramsay score and maintained a Ramsay score of 3-4. The sedation onset time, disablesedatives wake time, duration of mechanical ventilation, extubation success rate, ICU length of stay, and 28days mortality after admission to the ICU were compared between two groups. And calmer respiratorydepression, circulatory and delirium adverse reactions incidence were also compared. Results Thedifferences in patients’age, gender, and APACHEⅡ score between two groups were not significant ( P gt;0. 05) . Compared with the midazolam group, the dexmedetomidine group had more rapid onset of sedation[ ( 49. 80 ±8. 20) s vs. ( 107. 55 ±19. 65) s, P lt;0. 01] , shorter wake-up time [ ( 18. 90 ±2. 30) min vs. ( 40. 82 ±19. 85) min, P lt;0. 01] , shorter duration of mechanical ventilation [ ( 4. 9 ±1. 6) d vs. ( 7. 8 ±2. 5) d,P lt;0. 01] , higher successful extubation rate ( 79. 41% vs. 58. 82% , P lt;0. 01) , and shorter ICUlength of stay[ ( 6. 5 ±2. 5) d vs. ( 9. 6 ±3. 4) d, P lt;0. 05] . Dexmedetomidine had lower respiratory depression rate, littleeffects on hemodynamics, lower occurrence and short duration of delirium. Conclusion It is highlyrecommended that dexmedetomidine be used for sedation in AECOPD patients with mechanical ventilation.
Objective To investigate the effects of immune—enhancing enteral nutritioin therapy on the inflammatory reaction and immune function in the rats of ventilation-induced lung injury．Methods Fourty rats were divided into four groups(EN1、EN2、SEN1、SEN2，n=10)．All groups were performed mechanic ventilation and fed isocaloric enteral nutrition．EN1 group：tidal Volume(VT) =8 mL／kg，traditional enteral nutrition；EN2 group：VT=40 mL／kg，traditional enteral nutrition；SEN1 group：VT：8 mL／kg，immune-enhancing enteral immunonutrition；SEN2 group：VT=40 mL／kg，immune-enhancing enteral immunonutrition．Lymphocyte subsets，TNF-α，IL-6 and contents of arachidonic acid(AA)were determined at different time point(0，4，24，72 h after ventilation)．Results The levels of CD3+，CD4+，CD4+／CD8+ in SEN2 group were lower(Plt;0.05)than in EN1，EN2 and SEN1 group after 24，72 h of ventilation．The serum concentrations of TNF-α，IL-6 and AA were significantly lower in EN2 than in other three groups(P lt;0.05)．Conclusion Immune-enhancing enteral nutrition feeding prior to machanie ventilatioin can alleriate the damage of immunological function and reduce infl ammotory responses
Objective To investigate the curve correlation between ventilation pressure and tidal volume in assisted mechanical ventilation with facemask during anesthesia induction. Methods Between January and August 2015, 120 patients, American Society of Anesthesiology Ⅰ-Ⅱ, undergoing selective gynecological surgery were randomly divided into four groups: groups P5, P10, P15 and P20, with 30 patients in each group. Mask ventilation pressure for the four groups were respectively 5, 10, 15 and 20 cm H2O (1 cm H2O=0.098 kPa). Patients were ventilated by preset ventilation pressure and frequency based on different groups after loss of consciousness. Mean ventilation volume (mean value of three tidal volumes) and end-tidal carbon dioxide pressure (PetCO2) were recorded for analysis. Results There was no significant difference among the four groups in patient’s general condition (P>0.05). The tidal volume of assisted mechanical ventilation increased with ventilation pressure degrees, and the differences among the four groups were significant (P<0.05). After curve regression analysis, tidal volume and ventilation pressure showed a positive linear correlation when ventilation pressure was set at 5-20 cm H2O, and the correlation equation was: tidal volume = 33.612×ventilation pressure-53.155. PetCO2 in P5 group was lower than those in the other three groups (P<0.05), while there were no significant differences among groups P10, P15 and P20 (P>0.05). Conclusion When ventilation pressure is set at 5-20 cm H2O in assisted mechanical ventilation with facemask during anesthesia induction, tidal volume and ventilation pressure show a positive linear correlation.
ObjectiveTo explore the application of pulmonary ventilation and perfusion imaging (V/P SPECT/CT) in quantitative evaluation of ventilation and perfusion function and its potential value in guiding local treatment of lung in patients with asthma.MethodsA total of 20 patients with asthma were included in this study. All patients underwent V/P SPECT/CT and pulmonary function test, and symptoms were assessed by the ACT questionnaire. Patients were graded for degree of airway obstruction according to V/ P SPECT/CT image visual scoring criteria. The comprehensive lung function (%) of the patients was quantitatively evaluated by combining the ventilation and perfusion defect of each lung segment in V/P imaging. The correlation between the degree of airway obstruction, comprehensive lung function, pulmonary function test and ACT score was analyzed.ResultsV/P SPECT/CT imaging can be used to grade the degree of airway obstruction in asthma patients (0-3 grade). Airway obstruction grading by V/P SPECT/CT visual score was associated with predictive forced expiratory volume in one second (FEV1%pred) of patients (r=–0.74, P<0.001). V/P SPECT/CT can also comprehensively evaluate ventilation and perfusion function in patients with asthma, and comprehensive lung function measured by this method was also correlated with FEV1%pred (r=0.629, P=0.003). V/P SPECT/CT can be used to quantitatively analyze the percentage of ventilation and perfusion function in each lung lobe. Compared with V/P SPECT/CT results, the CT volume overestimates the contribution in the upper lobes, and underestimates the lower lobes contribution to overall function.ConclusionsV/P SPECT/CT can be used as a new method to directly reflect the degree of airway obstruction in patients with asthma. Moreover, it can comprehensively and quantitatively evaluate the ventilation and perfusion function of asthma patients. V/P SPECT/CT can also be used to evaluate lobe function in patients with asthma, helping to identify the heterogeneity of changes in pulmonary function in patients with asthma, and has potential value for future treatment targeting specific areas of the lung.
Objective To evaluate the association between pressure-controlled ventilation-volume guaranteed (PCV-VG) mode and volume-controlled ventilation (VCV) mode on postoperative pulmonary complications (PPCs) in patients undergoing thoracoscopic lung resection. Methods A retrospective cohort analysis of 329 patients undergoing elective thoracoscopic lung resection in West China Hospital of Sichuan University between September 2020 and March 2021 was conducted, including 213 females and 116 males, aged 53.6±11.3 years. American Society of Anesthesiologists (ASA) grade wasⅠ-Ⅲ. The patients who received lung-protective ventilation strategy during anesthesia were divided into a PCV-VG group (n=165) and a VCV group (n=164) according to intraoperative ventilation mode. Primary outcome was the incidence of PPCs during hospitalization. Results A total of 73 (22.2%) patients developed PPCs during hospitalization. The PPCs incidence of PCV-VG and VCV was 21.8% and 22.6%, respectively (RR=0.985, 95%CI 0.569-1.611, P=0.871). Multivariate logistic regression analysis showed that there was no statistical difference in the incidence of PPCs between PCV-VG and VCV mode during hospitalization (OR=0.846, 95%CI 0.487-1.470, P=0.553). Conclusion Among patients undergoing thoracoscopic lung resection, intraoperative ventilation mode (PCV-VG or VCV) is not associated with the risk of PPCs during hospitalization.
Objective To investigate the effects of different ventilation modes on postoperative pulmonary complications in elderly patients undergoing abdominal surgery. Methods The patients who underwent upper abdominal surgery under general anesthesia in Chengdu Office Hospital of the People’s Government of Tibet Autonomous Region between February 2020 and February 2021 were selected. Patients were randomly divided into volume controlled ventilation (VCV) group, pressure controlled ventilation (PCV) group, and pressure controlled ventilation-volume guarantee (PCV-VG) group according to the random number table method. All the three groups adopted the internationally recognized lung protective ventilation strategy. The transcutaneous arterial oxygen saturation and respiratory mechanics indicators of three different time periods, as well as pulmonary symptoms and signs and laboratory imaging examinations 7 days after surgery were recorded. The incidence of postoperative pulmonary complications in the three groups of patients were evaluated using the Melbourne Group Scale Version 2. Results A total of 120 patients were included, with 40 in each group. There was no statistically significant difference in the general situation of the three groups of patients (P>0.05). The platform pressure and compliance of three different time periods all changed over time (P<0.05). There were statistically significant differences in the occurrence of pulmonary complications and hospital stay among the three groups 7 days after surgery (P<0.05). Conclusion Under the internationally recognized lung protective ventilation strategy, PCV-VG mode can significantly reduce the incidence of pulmonary complications 7 days after abdominal surgery, shorten the length of hospital stay, and improve the quality of life in elderly patients.
ObjectiveTo explore the effectiveness of lung ultrasound-guided pulmonary rehabilitation training in ICU patients on mechanical ventilation.MethodsPatients on mechanical ventilation admitted to the ICU of a tertiary A-level hospital in Hefei city from July 2022 to December 2023 were selected and randomly divided into a control group and an experimental group using a random number table method. The control group received conventional pulmonary rehabilitation training, while the experimental group underwent lung ultrasound-guided pulmonary rehabilitation training. The differences in lung ultrasound scores, oxygenation index, diaphragm function, weaning success rate, and mechanical ventilation time were compared between the two groups on the 1st, 3rd, 5th, and 7th days of intervention.ResultsThe study was completed with 48 cases in the experimental group and 46 cases in the control group. Repeated measures ANOVA showed statistically significant intergroup effects, time effects, and interaction effects on lung ultrasound scores, oxygenation index, diaphragm mobility, and diaphragm thickness variability rate (P<0.05). The weaning success rate was higher in the experimental group than in the control group, and the mechanical ventilation time was shorter, with statistically significant differences (P<0.05).ConclusionsThe lung ultrasound-guided pulmonary rehabilitation training program can effectively improve the pulmonary status, oxygenation, and diaphragm function of ICU patients on mechanical ventilation, increase the success rate of weaning, shorten the mechanical ventilation time, and accelerate patient recovery.