Objective To investigate the physiological effects of different oxygen injection site on ventilatory status and oxygenation during noninvasive positive pressure ventilation ( NPPV) with portable noninvasive ventilators. Methods A prospective crossover randomized study was performed. Oxygen injection site was randomized into the outlet of the ventilator, the connection site between mask and circuit, and the mask under the condition of leak port immobilized in the mask. Oxygen flow was retained in the baseline level at the initial 5 to 10 minutes, and adjusted to obtain arterial oxygen saturation measured by pulse oximetry ( SpO2 ) ranging from 90% to 95% after SpO2 remains stable. SpO2 at the initial 5 to 10 minutes, oxygen flow, ventilatory status, oxygenation, hemodynamics and dyspnea indexes at0. 5 hour, 1 hour, and 2 hours of NPPV were compared between different oxygen injection sites. Results 10 patients were recruited into the study. Under the condition of the same oxygen flow, SpO2 with oxygen injection site in the outlet of the ventilator was significantly higher than that with oxygen injection site in the connection site between mask and circuit [ ( 98.9 ±0.9) % vs. ( 96.9 ±1.1) % , P =0. 003] , whereas SpO2 with oxygen injection site in the connection site between mask and circuit was significantly higher than that with oxygen injection site in the mask [ ( 96.9 ±1.1) % vs. ( 94.1 ±1.6) %, P = 0.000] . Oxygen flow with oxygen injection site in the mask was statistically higher than that with oxygen injection site at other sites ( P lt; 0.05) . Arterial oxygen tension/ oxygen flow with oxygen injection site in the outlet of the ventilator was significantly higher than that with oxygen injection site in the connection site between mask and circuit ( 67.9 ±31.1 vs. 37.0 ±15.0, P =0.007) , and than that with oxygen injection site in the mask ( 67.9 ± 31.1 vs. 25.0 ±9.1, P = 0.000) . pH, arterial carbon dioxide tension, hemodynamics and dyspnea indexes were not significantly different between different oxygen injection sites ( P gt; 0.05) .Conclusions When portable noninvasive ventilator was applied during NPPV, oxygen injection site significantly affects improvement of oxygenation, and shows a trend for affecting ventilatory status and work of breathing. When the leak port was immobilized in the mask, the nearer oxygen injection site approaches the outlet of the ventilator, the more easily oxygenation is improved and the lower oxygen flow is demanded.
ObjectiveTo investigate the prevalence and risk factors of deep venous thrombosis (DVT) in patients with acute exacerbation of chronic obstructive pulmonary disease (COPD). MethodsOne hundred and eight patients with acute exacerbation of COPD admitted between March 2009 and September 2010 were consecutively included.On admission,color Doppler ultrasound examination of lower extremities was performed for diagnosing DVT in all cases.The patients with DVT were compared with those without DVT in demographics,symptoms,physical signs,risk factors and laboratory examination including Ⅷ factor and von Willebrand factor (VWF). ResultsAmong 108 patients with acute exacerbation of COPD,DVT was detected in 11 cases (10.1%).In the COPD patients with DVT,the duration of hospitalization was longer (P<0.001) and the mechanical ventilation requirement increased (P=0.024) compared those without DVT.Other indicators for more possibility of DVT were immobility over 3 days (P=0.001),pneumonia as concomitance (P=0.004),type Ⅱ respiratory failure (P=0.011),and current smoking (P=0.002).The plasma leukocytes,D-dimer and Ⅷ factor levels were significantly higher in the COPD patients with DVT than those without DVT (P=0.005;P<0.001;P=0.009). ConclusionThe incidence of DVT in patients with acute exacerbation of COPD is 10.1%.The prevalence of DVT is higher in distal extremities than that in proximal,especially the intermuscular veins.The patients with acute exacerbation of COPD have a higher risk of DVT when immobilized over 3 days,complicated by pneumonia or type Ⅱ respiratory failure,and having a high levels of plasma leukocytes,D-dimer and Ⅷ factor.
ObjectiveTo investigate the physiologic effects of different pressure assist (PA) on ventilatory status,oxygenation and work of breathing (WOB) when a new generation of proportional assist ventilation (PAV) is applied in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). MethodsA prospective,crossover randomized physiologic study was performed.80%PA,60%PA and 40%PA was sequentially randomized to be applied with the duration of 30 minutes,and pressure support ventilation (PSV) with the duration of 30 minutes was applied before each PA.Ventilatory status, oxygenation,dyspnea indexes in PSV and different PA were compared,and WOB of patients and ventilator were compared in different PA. ResultsTwenty-eight patients were recruited into the study.With the decrease of PA,peak inspiratory pressure (PIP),mean airway pressure (Pm),and tidal volume (VT) decreased gradually (P>0.05),respiratory rate (RR) increased gradually (P<0.05),while minute volume (MV),heart rate (HR),systolic blood pressure (SBP),mean arterial pressure (MAP),pH,arterial carbon dioxide tension (PaCO2),and arterial oxygen tension/inspired oxygen fraction (PaO2/FiO2) did not change significantly (P>0.05).Compared with PSV mode,PIP increased significantly in 80%PA (P<0.05),decreased significantly in 60%PA and 40%PA (P<0.05).Pm did not change significantly in 80%PA (P>0.05),decreased significantly in 60%PA and 40%PA (P<0.05).VT increased significantly in 80%PA (P<0.05),decreased significantly in 60%PA and 40%PA (P<0.05).RR did not change significantly in 80%PA (P>0.05),increased significantly in 60%PA and 40%PA (P<0.05).MV did not change significantly in 80%PA (P>0.05),decreased significantly in 60%PA and 40%PA (P<0.05).With the decrease of PA,Borg score and scale for accessory muscle use increased gradually (P<0.05).Compared with PSV mode,Borg score and scale for accessory muscle use did not change significantly in 80%PA (P>0.05),increased significantly in 60%PA and 40%PA (P<0.05).WOB of patients in 40%PA was significantly higher than that in 60%PA (P=0.000) and that in 80%PA (P=0.000),while which in 60%PA was significantly higher than that in 80%PA (P=0.000).On the contrary,WOB of ventilator in 40%PA was significantly lower than that in 60%PA (P=0.004) and that in 80%PA (P=0.000),while which in 60%PA was significantly lower than that in 80%PA (P=0.000). ConclusionThe new generation of PAV can safely and effectively provide respiratory support to patients with AECOPD.Respiratory pattern,levels of dyspnea and accessory muscle use in 80%PA are similar with those in PSV.With the decrease of PA,levels of spontaneous breathing and WOB increase and dyspnea worsens.PAV can promote spontaneous breathing and prevent respiratory muscle disuse atrophy even more, but easily lead to respiratory muscle fatigue with inappropriate use.
ObjectiveTo explore the early predictive value of Wells score and D-dimer for acute pulmonary embolism. MethodsEighty-two cases with acute pulmonary embolism comfirmed by computed tomography pulmonary angiography and (or) lung ventilation/perfusion scan were retrospectively studied from October 2013 to October 2014 in our hospital. Another 82 cases without acute pulmonary embolism in the chest pain center simultaneously were selected as control group. The data on admission were analyzed including Wells score, D-dimer, pH, PCO2, PO2, P(A-a)O2, brain natriuretic peptide, troponin I of two groups of patients. Relevant variables were selected by multivariate logistic regression analysis. The receiver operating characteristic (ROC) curve was made by sensitivity as the ordinate and 1 minus specificity as abscissa. The area under ROC curve (AUC) for relevant variables was calculated and the variable with higher AUC was selected. The best threshold, sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were achieved from the ROC curves. ResultsThe multivariate logistic regression analysis showed that Wells score (OR=8.114, 95%CI 1.894-34.761, P=0.005) and D-dimer (OR=1.009, 95%CI 1.001-1.017, P=0.021) could predict APE early. The AUC, sensitivity, specificity, PPV, NPV of Wells score for the early prediction of patients with acute pulmonary embolism were 0.990, 50.0%, 100.0%, 100.0%, 66.7%, respectively. The AUC, sensitivity, specificity, PPV, NPV of D-dimer for the early prediction of patients with acute pulmonary embolism were 0.986, 95.1%, 97.6%, 97.5%, 95.2%, respectively. ConclusionWells score and D-dimer have high predictive value in patients with acute pulmonary embolism, and can be used in preliminary screening of acute pulmonary embolism in the emergency department.
Objective To investigate the changes of microRNA-150 ( miR-150) in peripheral blood leukocytes in sepsis patients, and their relationship with expression of immune cytokines and sepsis severity. Methods The level of mature miR-150 was quantified by real-time reverse transcriptase-polymerase chain reaction (RT-PCR) and normalized to that of control miRNA, U6, in peripheral blood leukocytes of 40 patients with sepsis, 20 patients with systemic inflammatory response syndrome ( SIRS) , and 20 normal individuals. Serum concentrations of tumor necrosis factor alpha (TNF-α) and interleukin-10 (IL-10) were measured by enzyme-linked immunoabsorbent assay in all subjects. The sequential organ failure assessment ( SOFA) score systemwas used to evaluate the severity of sepsis. The relationships between miR-150 and the white blood cell count ( WBC) , TNF-α, IL-10 and SOFA score of the sepsis patients were analyzed. Results MiR-150 was stable for at least 5 days when specimen stored at 4 ℃ and the determination of miR-150 had a broad linear detecting range ( 6. 97-6. 97 ×104 pg/ μL RNA, the lowest detecting limit: 6. 97 pg/μL RNA,r=0.999) .MiR-150 expression in the peripheral blood leukocytes in the sepsis group was significantly lower than that in the healthy control group ( Plt;0.01) , while WBC, IL-10 and IL-10/TNF-α ratio were significantly higher ( Plt;0.05) . There was no significant difference in levels of miR-150, IL-10, IL-10/TNF-α ratio, and WBC between the sepsis group and the SIRS group (Pgt;0.05) . There was no significant difference in serum concentrations of TNF-α among three groups ( Pgt;0.05) . MiR-150 expression in non-survivor sepsis patients was significantly lower than that in survivor sepsis patients (Plt;0.05) , while serum IL-10 and IL-10/TNF-αratio were significantly higher (Plt;0.01) , but there was no significant difference in serum TNF-α between the non-survivor group and the survivor group ( Pgt;0.05) . There was significantly negative correlation between miR-150 and SOFA score, TNF-α and IL-10( r=-0. 619, - 0.457, -0. 431, Plt;0.05, respectively) , but no correlation between miR-150 and WBC ( r =-0. 184, Pgt;0.05) . There was no relationship between serum TNF-α, IL-10, IL-10 /TNF-α ratio or SOFA score ( Pgt;0.05) . Conclusions MiR-150 expression in the peripheral blood specimens is significantly decreased in sepsis patients. The expression level of miR-150 not only reflect the situation of inflammatory response, but also may be used as a prognostic marker in sepsis, as it can reflect the severity of sepsis in certain degree.
Objective To improve the knowledge of pulmonary artery sarcoma ( PAS) and early diagnosis.Methods The clinical data of 8 patients with PAS confirmed by biopsy from April 2001 to April 2012 in Beijing Anzhen Hospital were retrospectively analyzed. Results There were 5 males and 3 females, with mean age of 46. 75 ±11. 47 years [ range: 32-67 years] . The main clinical manifestations were chest tightness, shortness of breath, intermittent syncope, heart palpitations at exertion, etc. Laboratory examinations showed the patients with PAS have no obvious hypoxemia and most of them have normal D-dimer level. Echocardiography revealed pulmonary hypertension, right ventricular enlargement, and echo of massive lumps in main pulmonary truck. Lower limb veins were normal in color doppler ultrasonography. Chest X-ray revealed prominent pulmonary artery segment, full segment of the right pulmonary artery, an increased hilum and pleural effusion. CT pulmonary angiography showed expansion of pulmonary artery, large filling defect in main pulmonary truck and left or right pulmonary artery, combined with pericardial effusion, pleural effusion. Lung ventilation/perfusion imaging did not match, showing radioactive sparse and defects in multiple lung segments and subsegments, involved 3 to 13 lung segments. Pulmonary angiography showed filling defects in the main pulmonary artery, left or right pulmonary artery. 8 patients were confirmed pathologically after operation. Pathological results showed leiomyosarcoma differentiation in 3 cases, undifferentiated sarcoma in2 cases, and undefined pathological type in 3 cases. All 8 patients were misdiagnosed as pulmonary embolism before surgery. The average days of misdiagnosis were 85. 6 ±21. 5 days. 7 cases were given simple surgical resection, one case underwent surgical resection combined with radiotherapy and chemotherapy. 7 cases were relieved and discharged, and one case died. Conclusion PAS is a rare disease clinically and is easily misdiagnosed as pulmonary embolism. Clinicians should enhance the recognition in order to diagnose early and treat comprehensively.