Objective To study the role of ubiquitin-proteasome pathway in diaphragm of COPD rats. Mathods Thirty rats were divided into a normal control group and a COPD group. COPD model was established by exposure to cigarette smoke for three months. The protein levels of E2-14k and proteasome subunit C8 in diaphragms were measured by Western blot. The mRNA levels of ubiquitin and proteasome subunit C2 in diaphragms were measured bymeans of realtime polymerase chain reaction( RT-PCR) . Results Compared with the control group, the protein expression of E2-14k increased significantly in the COPD group ( 0. 81 ±0. 28 vs 0. 50 ±0. 25, P lt;0. 05) , but C8 protein level was not significantly different between the two groups( P gt;0. 05) . The mRNA expression of ubiquitin increased significantly in the COPD group( 0. 89 ±0. 20 vs 0. 50 ±0. 15, P lt;0. 05) , but C2 mRNA level was not significantly different between the two groups ( P gt; 0. 05 ) . Conclusions The mRNA and protein expressions of ubiquitin-proteasome pathway in diaphragmincreased significantly in COPD rats, suggesting that the activity of ubiquitin-proteasome pathwayincreased, which lead to an increase of protein degradation.
ObjectiveTo investigate the clinical features,treatment and pathogenesis of shrinking lung syndrome (SLS). MethodsA patient of systemic lupus erythematosus(SLE)with SLS as initial manifestation was reported.Literatures about SLS were comprehensively reviewed for its clinical characteristics and pathogenesis. ResultsA 27-year-old man was admitted with chief complaint of intermittent dyspnea and chest pain in 2009.Chest X-ray showed small lung volume and elevated diaphragms.Chest CT revealed bilateral pleural thickness and multiple atelectasis,without significant sign of interstitial fibrosis.Lung function showed restrictive pattern.Routine blood test revealed declined white blood cell and platelet count.C3 and C4 were declined.The autoantibody test revealed positive ANA,dsDNA,AHA,and RNP antibody.A diagnosis of SLE with SLS was made.The patient received corticosteroids and immunosuppressive therapy and was followed up for 5 years.His symptoms had relieved,but there was no obvious improvement in chest radiology and lung function.A total of 118 SLS cases were recorded in literature review,among which 100 were females and 18 were males.The average age was 32.98±14.66 years.Common clinical features of SLS included dyspnea,chest pain,orthopnea,breathlessness,and decreased breath sound.Radiology revealed small lung volume,elevated diaphragm,and dysfunction of diaphragm.Lung function showed restrictive pattern.The primary treatment of the disease was corticosteroid and immunosuppressive agents.The use of theophylline,β-agonist and rituximab was also reported. ConclusionWe should be aware of SLS in patients with SLE or other autoimmune diseases when they present with unexplained dyspnea.
ObjectiveTo clarify the risk factors of diaphragmatic dysfunction (DD) after cardiac surgery with extracorporeal circulation. MethodsA retrospective analysis was conducted on the data of patients who underwent cardiac surgery with extracorporeal circulation in the Department of Cardiovascular Surgery of Peking University People's Hospital from January 2023 to March 2024. Patients were divided into two groups according to the results of bedside diaphragm ultrasound: a DD group and a control group. The preoperative, intraoperative, and postoperative indicators of the patients were compared and analyzed, and independent risk factors for DD were screened using multivariate logistic regression analysis. ResultsA total of 281 patients were included, with 32 patients in the DD group, including 23 males and 9 females, with an average age of (64.0±13.5) years. There were 249 patients in the control group, including 189 males and 60 females, with an average age of (58.0±11.2) years. The body mass index of the DD group was lower than that of the control group [(18.4±1.5) kg/m2 vs. (21.9±1.8) kg/m2, P=0.004], and the prevalence of hypertension, chronic obstructive pulmonary disease, heart failure, and renal insufficiency was higher in the DD group (P<0.05). There was no statistical difference in intraoperative indicators (operation method, extracorporeal circulation time, aortic clamping time, and intraoperative nasopharyngeal temperature) between the two groups (P>0.05). In terms of postoperative aspects, the peak postoperative blood glucose in the DD group was significantly higher than that in the control group (P=0.001), and the proportion of patients requiring continuous renal replacement therapy was significantly higher than that in the control group (P=0.001). The postoperative reintubation rate, tracheotomy rate, mechanical ventilation time, and intensive care unit stay time in the DD group were higher or longer than those in the control group (P<0.05). Multivariate logistic regression analysis showed that low body mass index [OR=0.72, 95%CI (0.41, 0.88), P=0.011], preoperative dialysis [OR=2.51, 95%CI (1.89, 4.14), P=0.027], low left ventricular ejection fraction [OR=0.88, 95%CI (0.71, 0.93), P=0.046], and postoperative hyperglycemia [OR=3.27, 95%CI (2.58, 5.32), P=0.009] were independent risk factors for DD. ConclusionThe incidence of DD is relatively high after cardiac surgery, and low body mass index, preoperative renal insufficiency requiring dialysis, low left ventricular ejection fraction, and postoperative hyperglycemia are risk factors for DD.
Objective To explore the feasibility of ultrasound diagnosis of diaphragmatic paralysis in patients with ventilation after congenital heart disease surgery. Methods There were 542 patients with congenital heart disease after surgery, difficult to be weaned off the ventilator or suspected diaphragmatic paralysis of the patients, respectively, in the ventilator continous positive pressure breathing (CPAP) mode and completely independent breathing state, whose ultrasound examination of diaphragm function was conducted to determine the presence of diaphragmatic paralysis in our hospital between January 1, 2013 and April 30, 2016. There were 327 males and 215 females at age of 14±32 months. The results of ultrasound diagnosis between ventilator CPAP mode and completely spontaneous breathing mode were compared. Results Five hundred and forty-two patients underwent ultrasound diaphragmatic examination. The results of bedside ultrasound were completely diagnosed: in completely spontaneous breathing, 82 patients who were diagnosed as diaphragmatic paralysis, including 39 on the right, 25 on the left, 18 on both sides; in CPAP mode, 82 patients who were diagnosed as diaphragmatic paralysis, 38 on the right, left 25, bilateral 19. Using ultrasound in CPAP mode to diagnose diaphragmatic paralysis after congenital heart disease surgery, compared with the completely spontaneous breathing state, the sensitivity was 100.0% and the specificity was 99.9%. Conclusion It is accurate and feasible to diagnose the presence of diaphragmatic paralysis in patients with ventilation after congenital heart disease surgery.
Objective To investigate the changes of respiratory mechanics in response to elevated respiratory central drive and their impacts on the inspiratory signals detection.Methods 10 normal volunteers were recruited for the study from the colleagues of the State Key Laboratory of Respiratory Disease. Rebreathing method was used to increase the end expiratory PCO2 ( PCO2 -ET) to the subject’s maximal tolerance in order to stimulate the increase of respiratory central drive. The changes of respiratory mechanics in response to elevated respiratory central drive and their impacts on the initiation signals of inspiration were observed.Results After re-breathing, the average maximal tolerated PCO2 -ET was ( 81. 2 ±6. 6) mm Hg. As the PCO2 -ET rising, electromyogram of diaphragmatic muscle ( RMSdi ) ,transdiaphragmatic pressure ( Pdi ) and tidal volume ( VT ) increased progressively while the time of respiratory cycle ( Ttot ) shorten gradually. As the PCO2 -ETlevel increased frombaseline [ PCO2 -ET( level-0) ] to the maximal level [ PCO2 -ET( level-4) ] , RMSdi increased from( 17. 17 ±12. 41) μV to ( 147. 99 ±161. 64) μV,Pdi and VT increased from ( 7. 5 ±1. 7) cmH2O and ( 0. 68 ±0. 27) L to ( 26. 13 ±11. 51) cm H2O and ( 2. 21 ±0. 37) L respectively, while Ttot shorten from ( 2. 91 ±0. 85) s to ( 1. 92 ±0. 39) s. These four parameters of respiratory mechanics, RMSdi, Pdi, VT and Ttot, were highly correlated linearly with PCO2 -ET ( r value was 0. 956, 0. 973,0. 956 and 0. 89 respectively, all P lt;0. 001) . At the start of inspiration, the first detectable signal was electromyogramof diaphragmatic muscle ( RMSdi) , followed by mouth pressure ( Pm)and inspiratory flow ( Flow) on time sequence. As the rising of PCO2 -ET, the time lag of Pmand Flow from RMSdi after the initiation of inspiration increased gradually. However, the time lag between Flow and Pm remained constant. Conclusions At the start of inspiration, the signal of RMSdi appears first as compared with Pm and Flow. As the rising of PCO2 -ET, the time lag of Pmand Flow fromRMSdi after the initiation of inspiration increased gradually, suggesting RMSdi is more sensitive inspiratory signal, which might be used for triggering of ventilator in order to improve the synchronization, especially in the situation of elevated respiratory central drive.
膈神经是维持呼吸功能的主要神经, 由颈3 ～5 神经组成, 在维持正常通气功能中占有重要的地位。膈肌位于胸腔和腹腔之间, 为向上膨隆呈穹窿形的扁薄阔肌, 是主要的呼吸肌, 在呼吸运动中起着非常重要的作用。膈肌起搏即通过电刺激膈神经或膈肌使膈肌收缩, 维持患有膈肌功能障碍患者的自然负压呼吸。自发现电刺激能引起膈肌收缩至今已有200 多年历史, 该技术应用于临床也已有60 余年历史[1] 。
ObjectiveTo investigate the relationship of diaphragmatic mobility (ΔM) evaluated by ultrasonography with quality of life and athletic ability in patients with chronic obstructive pulmonary disease (COPD) , and analyze the factors those affect the diaphragmatic mobility.MethodsA total of 48 male patients with stable COPD were recruited in the study. The body height, body weight, diaphragmatic mobility, airflow obstruction (FEV1%pred), and exercise capacity (6MWD) were measured. The quality of life was assessed using the St. George’s Respiratory Questionnaire (SGRQ).ResultsThe minimum value of ΔM was 1.89 cm and the maximal value was 8.11 cm in the COPD patients. There were significant correlationship between ΔM and the SGRQ score of the total score, symptom score, impact points, activity points and 6MWD, with correlation coefficients of –0.474, –0.416, –0.432, –0.502 and 0.536, respectively. Multivariate stepwise regression analysis showed that the factors influencing ΔM were height (β=0.407, P=0.021) and FEV1%pred (β=–0.391, P=0.035).ConclusionsDiaphragmatic mobility and quality of life are closely related in COPD patients. The height and FEV1%pred have the greatest effect on diaphragmatic activity. The smaller diaphragm mobility is relevant to the worse quality of life and the smaller activity capacity.