Objective To investigate the therapeutic effects of biphasic positive airway pressure (Bilevel) ventilation and volume ventilation plus [VV+，including volume control plus (VC+) and volume support (VS)] on respiratory failure in patients with chronic obstructive pulmonary disease (COPD).Methods 63 patients with COPD complicated by acute respiratory failure were intubated and underwent mechanical ventilation for at least 24 hours.At the first patients were underwent assist-control (A/C) ventilation for 2 to 4 hours to obtain the suitable basic ventilatory parameters.Meanwhile，the hemodynamics and oxygen dynamic parameters were measured.Then the patients were randomly allocated to three groups with 21 patients in each group and the ventilation mode was switched to Bilevel，VC+ and A/C mode correspondingly.The setting parameter was identical in three modes.In the process of weaning，patients in Bilevel group were ventilated with Bilevel and pressure support ventilation (PSV) mode at each pressure level，and subdivided into Bilevel and PSV 1 group accordingly.In VC+ group，the mode was switched to VS and PSV mode and subdivided into VC+ group and PSV 2 group,respectively.Every mode was run for 30 minutes while the ventilation function，blood gas exchange and lung mechanics index were measured.Results In the initial stage，the airway peak pressure (PIP) of Bilevel and VC+ mode obviously decreased，and the respiratory compliance was higher compared to the A/C mode. The effectiveness of Bilevel and A/C was equivalent in improving alveolar ventilation and oxygenation.The difference in the change of circulation function and blood gas between the two groups were not significant (Pgt;0.05).In the process of weaning，the effectiveness of Bilevel and VV+ was equal to PSV.The changes of breathing mode and blood gas between the two groups had no significant differences.Conclusions Bilevel and VV+ mode ventilation can be used in the whole mechanical ventilation for acute respiratory failure due to COPD with lower PIP，higher respiratory compliance compared to A/C model and similar performance as PSV during mechanical ventilation withdrawn.
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.
ObjectiveTo compare the indirect calorimetry (IC) measured resting energy expenditure (MREE) with adjusted Harris-Benedict formula calculating resting energy expenditure (CREE) in the mechanically ventilated surgical critically ill patients and to evaluate the relationship between the resting energy expenditure (REE) with the severity of illness. MethodsTwenty-one patients undergonging mechanical ventilation for critical illness in the intensive care unit of general surgery between August 2008 and February 2010 were included in this study. Data during the study period of nutrition support were collected for computation of the severity of critical illness by acute physiology and chronic health evaluation Ⅱ scores (APACHE Ⅱ scores) and organ dysfunction scores (Marshall scores). MREE was measured by using IC of the MedGraphics CCM/D System within the first 7 d after nutrition therapy. CREE was calculated by using the HarrisBenedict formula adjusted with correction factors for illness at the same time. According to APACHE Ⅱ scores on admission, the enrolled patients were divided into two groups: APACHEⅡ score ≥20 scores group (n=8) and APACHE Ⅱ score lt;20 scores group (n=13), and the differences between MREE and CREE of patients in two groups were determined. ResultsThe reduction of variation tendency in CREE other than MREE in the enrolled patients within the first week of nutritional support was statistical significance (Plt;0.001). The CREE of patients 〔(1 984.49±461.83) kcal/d〕 was significantly higher than the MREE 〔(1 563.88±496.93) kcal/d〕 during the first week of nutritional support (Plt;0.001). The MREE on the 0, 1, 2, and 4 d after nutrition therapy were statistically significant lower than CREE at the same time interval in these patients (Plt;0.01), and the differences at the other time points were not significant (Pgt;0.05). There was a trend towards a reduction in APACHE Ⅱ and Marshall scores within the first week of nutrition therapy that reached statistical significance (Plt;0.001). During the first week of nutrition therapy, APACHEⅡ and Marshall scores of patients in ≥20 scores group were significantly higher than those in lt;20 scores group, respectively (Plt;0.05 or Plt;0.01), and the reductions of APACHE Ⅱ scores and Marshall scores were significant in patients of two groups (Plt;0.001). A significant positive correlation was found between CREE with APACHE Ⅱ scores (r=0.656, Plt;0.001) and Marshall scores (r=0.608，Plt;0.001) in patients within the first week after nutrition support. Although no statistically significant correlation was observed between MREE and APACHEⅡ scores (r=-0.045， P=0.563), a significant positive correlation was observed between MREE and Marshall scores (r=0.263, P=0.001) within the first week after nutrition therapy. There was no correlation between MREE and CREE (r=0.064, P=0.408) in patients at the same time interval. The reduction of MREE of patients in ≥20 scores group other than in lt;20 scores group was statistically significant within the first week after nutrition therapy (P=0.034). In addition, the MREE of patients in ≥20 scores group were not significantly different from those in lt;20 scores group (Pgt;0.05), and the mean CREE was not different in two groups patients within the first week of nutritional therapy 〔(1 999.55±372.73) kcal/d vs. (1 918.39±375.27) kcal/d, P=0.887〕. CREE was significantly higher than MREE of patients in ≥20 scores group within the first week except the 3 d and 5 d after nutrition therapy (Plt;0.05), while in lt;20 scores group CREE was significantly higher than MREE in patients only within the first 3 d after nutrition therapy (Plt;0.05 or Plt;0.01). MREE and CREE of patients in ≥20 scores group were not different from those in lt;20 scores group, respectively (Pgt;0.05).
Objective To study the influencing factors for duration of mechanical ventilation in chronic obstructive pulmonary disease ( COPD) patients with type II respiratory failure. Methods Twenty-eight cases of mechanical ventilated COPD patients with type II respiratory failure were enrolled from March 2006 to March 2008 in Beijing Shunyi Hospital. They were divided into two groups based on their duration of ventilation: ≤7 d group as group I, and gt; 7 d as group II. Data of heart rate and blood pressure were recorded before the trachea intubation. Clinical data of blood routine, blood gas analysis and serum biochemistry were collected and analyzed. Previous history, smoking history and subsequent complications were also recorded. Results Heart rate in the group II were significantly higher than which in the group I[ ( 121. 50 ±17. 20) /min vs ( 103. 08 ±19. 97) /min, P lt;0. 05] . The incidences of upper gastrointestinal hemorrhage and blood pressure fall immediately after intubation were 63% and 88% respectively in the group II, which were significantly higher than the group I ( 0 and 25% ) . The levels of albumin, pre-albumin, Na+ , PaO2 were ( 29. 06 ±5. 00) g /L, ( 66. 36 ±17. 72) mg/L,( 138. 45 ±4. 74) mmol /L and ( 49. 06 ±20. 11) mm Hg respectively in the group II. While in the group I, those were ( 37. 11 ±2. 73) g /L, ( 127. 70 ±35. 84) mg/L, ( 143. 29 ±3. 42) mmol /L and ( 72. 25 ±38. 69) mm Hg respectively, which showed significant differences compared with the grouop II. The incidence of previous concomitant cerebral infarction showed significant difference between the group I and group II( 33. 33% vs 0) .Conclusion The levels of albumin, pre-albumin, heart rate before the intubation, upper gastrointestinal hemorrhage and blood pressure fall immediately after the intubation are associated with duration of mechanical ventilation and may indicate the prognosis in COPD patients with type II respiratory failure.
Objective To explore the correlation between the levels of nitrite / nitrate( NO2 /NO3) in exhaled breath condensate ( EBC) and pulmonary infection in mechanically ventilated patients. Methods The clinical data from ventilated patients in critical care units of Peking University People’s Hospital from November 2006 to August 2007 were collected and analyzed. The patients’clinical pulmonary index score ( CPIS) were calculated. EBC of those patients were collected via endotracheal tube or tracheostomy cannula,and the concentrations of NO2 /NO3 were assayed. The level of NO2 /NO3 in different CPIS patients in 24 hours’ventilation, weaning proportion in 3 days and mortality in different NO2 /NO3 level patients were compared. The correlation of the CPIS and level of NO2 /NO3 were explored between survival and non-survival patients. Results A total of 76 patients were enroled. The NO2 /NO3 levels in patients of CPIS≤3, CPIS 3-6 and CPIS gt;6 in 24 hours of ventilation were ( 23. 31 ±5. 79) , ( 28. 72 ±9. 10) and ( 35. 42 ±12. 10) μmol / L respectively, with significantly differences between each other ( P lt; 0. 01) . The lower the patients’concentration of NO2 /NO3 was, the earlier the weaning and the lower the mortality were. The NO2 /NO3 levels on 4th and 7th day were detected in 24 survival patients and 23 non-survival patients. The difference of NO2 /NO3 levels between the survival patients and non-survival patients became significant on 7th day [ ( 29. 32 ±9. 52) μmol / L vs. ( 37. 22 ±12. 03) μmol / L, P lt; 0. 01] . Linear correlation analysis showed that the NO2 /NO3 level was positively correlated with CPIS ( r = 0. 76, P lt; 0. 01) . Conclusions The NO2 /NO3 level of EBC in ventilated patients is positively correlated to the severity of pulmonary infection, thus may be used as a new predictor for weaning and prognosis.
ObjectiveTo detect the concentration of 8-isoprostane (8-iso-PG) in exhaled breath condensate (EBC) of patients with or at risk for ARDS in ventilation, and investigate its clinical significance.MethodsFifty-five patients with or at risk for ARDS in ventilation admitted between February 2014 and June 2016 were recruited as an experimental group, and simultaneous 30 normal cases were recruited as a control group. Their EBC was collected with EcoScreen condenser. The EBC 8-iso-PG level of the patients between different grades of ARDS (mild, moderate, and sever) or at risk for ARDS was compared, and the correlation of EBC 8-iso-PG with the clinical indicators was analyzed.ResultsThe 8-iso-PG levels in EBC and serum of the patients with or at risk for ARDS in ventilation were higher than those in the control group [EBC: (44.83±11.58) ng/L vs. (19.47±4.06) ng/L; serum: (481.53±444.94) ng/L vs. (19.91±17.60) ng/L] (all P<0.05). The EBC 8-iso-PG of the patients with moderate ARDS (n=15) and severe ARDS (n=7) [(47.18±11.68) ng/L and (50.29±11.06) ng/L] was higher than those with mild ARDS (n=7) or at risk for ARDS (n=26) [(33.04±7.62) ng/L) and (37.17±11.08) ng/L] (all P<0.05). However EBC 8-iso-PG was not different between the patients with mild ARDS and those at risk for ARDS (P>0.05 ). The increased EBC 8-iso-PG could predict ARDS with an area under the receiver operating curve of 0.73. The EBC 8-iso-PG of the patients with or at risk for ARDS was correlated with lung injury score (r=0.418, P<0.01), PaO2/FiO2 (r=–0.378, P<0.05), chest radiograph scores (r=0.410, P<0.05), AaDO2 (r=0.368, P<0.05), and APACHEⅡ score (r=0.718, P<0.05).ConclusionEBC 8-iso-PG can reflect the oxidative stress in lung of ARDS patients in ventilation, and can contribute to the diagnosis and evaluation for moderate and severe ARDS.
Objective To evaluate the safety and diagnostic yield of transbronchial lung biopsy ( TBLB) performed in mechanically ventilated patients. Methods TBLB was performed in 19 mechanically ventilated patients form January 2001 to September 2007 in the ICU of Guangzhou Institute of Respiratory Diseases. The results of clinical data were retrospectively analyzed. Results A total of 19 patients were analyzed[ 9 female, 10 male, with amean age of ( 57. 94 ±15. 00) years] . Specific diagnoses were made in 9 cases ( 47. 4% ) by TBLB. The diseases included pulmonary aspergillus pneumonia in 4 cases ( 21. 0% ) ,lung cancer in 2 cases ( 10. 5% ) , radioactive pneumonia in 1 case( 5. 3% ) , Goodpasture’s syndrome in1case( 5. 3% ) , pulmonary tuberculosis in 1 case ( 5. 3% ) . Ten cases ( 52. 6% ) were not able to establish confirmed diagnoses including pulmonary interstitial fibrosis in 6 cases( 31. 6% ) and lung tissue nonspecific changes in 4 cases( 21. 0% ) . The treatment was adjusted according to the results of TBLB in 10 patients( 52. 6% ) . Complications associated with this procedure included episodes of bronchial hemorrhage of ≥30 mL in 4 cases ( 21. 0% ) , transient oxygen desaturation in 11 cases ( 57. 9% ) , hypotension in 5 cases ( 26. 3% ) , and transient tachycardia in 1 case ( 5. 3% ) without death and pneumothorax. Conclusions TBLB can be performed safely and has a diagnostic value in mechanically ventilated patients. TBLB should be considered as a diagnostic procedure before open lung biopsy.
Objective To analyze the clinical features and treatment of severe H1N1 influenza.Methods The clinical data of 34 patients with severe H1N1 influenza admitted to intensive care unit from October to December 2009 were reviewed. Results The patients aged 3 months to 60 years with an average of ( 13. 9 ±4. 5) years, of which 24 patients were younger than 7 years old. Fever( 30 cases) , cough( 32 cases) , progressive shortness of breath( 19 cases) were the main symptoms. White blood cell count was normal in 21 cases, increased in 6 cases, and decreased in 7 cases. Lymphocyte count was normal in 16 cases, increased in 12 cases, and decreased in6 cases. Chest X-ray films showed bilateral or unilateral patchy pulmonary fuzzy shadows in28 cases. Chest CT showed diffuse interstitial lesion in1 case, pleural effusion in 2 cases, and bronchiectasis in 1 case. The hepatic and myocardial enzymogramparameters were all abnormal.30 cases were treated by oseltamivir and ribavirin, 4 cases by methyllprednisolone, and 6 cases by gamma globulin. 8 cases underwent routine intubation and mechanical ventilation, and 5 cases received non-invasive mechanical ventilation. All 34 patients were cured. Conclusions Lung, heart, and liver are the major target organs in severe H1N1 influenza. Mechanical ventilatory support is an important treatment for severe H1N1influenza.
Objective To study the clinical feasibility of invasive mechanical ventilation with bilevel positive airway pressure（BiPAP） non-invasive ventilator in the stable patients needing prolonged mechanical ventilation.Methods Eleven patients with respiratory failure admitted in intensive care unit（ICU）of our department，who needed prolonged mechanical ventilation，between Jun 2004 and Nov 2007 were enrolled in the study and followed until death or Jan 2008.The arterial blood gas analysis data，length of stay(LOS)，LOS after changing to BiPAP non-invasive ventilator（Synchrony，Harmony，RESPIRONICS，VPAP III ST-A，RESMED），survival time after discharge(or fulfilled the discharge standards) were reviewed retrospectively.Results The settings of inspiratory pressure，expiratory pressure and respiratory rate of non-invasive ventilation were 21.3 (16-26) cm H2O，4 cm H2O，and 16 min-1，respectively.The LOS (or up to the discharge standard) was (91.5±50.2) days.The LOS (or up to the discharge standard) after changing to BiPAP ventilator was (23.5±12.2) days.The mean survival time after discharge (or up to the discharge standard) was (353.1±296.5) days.Four patients were still alive up to the end of the study.The arterial pH，PaCO2，PaO2，and SaO2 were not significant different before and after changing to BiPAP ventilator.Conclusion The mechanical ventilation with BiPAP non-invasive ventilator via tracheotomy tube is an alternative choice for stable patients needing prolonged mechanical ventilation.
Objective To investigate the outcome and prognostic factors of hospital mortality in patients with acute cerebrovascular disease requiring mechanical ventilation.Methods Data from 94 patients with acute cerebrovascular disease in central intensive care unit(ICU) were collected and retrospectively analyzed.Prognostic factors of hospital mortality were analyzed by univariate statistics and multivariate logistic regression.Results Hospital mortality was 53.2%(50/94).There was significance diference in parameters such as APACHE II score，blood glucose，lengh of hospital stay，lengh of ICU stay，time of mechanical ventilation，incision of trachea，lung infections，lesion loci and its naturer between the survival and non-survival groups（all Plt;0.05）.Multivariate logistic regression revealed that blood glucose，lung infections，diseased region under tentorium of cerebellum，time of mechanical ventilation were independent prognostic risk factors of hospital mortality(all Plt;0.05).Whereas the lengh of ICU stay was protective factor(Plt;0.05).Conclusion The hospital mortality is considerably high in patients with acute cerebrovascular disease requiring mechanical ventilation. The prognostic factors such as blood glucose and lung infections should be evaluate cautiously and prevented aggressively.