Objective To evaluate the sedative effects of fentanyl on ventilated patients in intensive care unit (ICU ).Methods Thirty orotracheal intubated and mechanical ventilated medical patients in ICU were randomly divided into two groups，ie.Midazolam group (group M) and midazolam combined with fentanyl group with a proportion of 100∶1 (group M+F) The sedatives were continuously intravenously infused to achieve a target motor activity assessment scale (MAAS) of 3 and ventilator synchrony score of adaptation to the intensive care environment (ATICE) ≥3 after loading dose of midazolam.The sedation level was evaluated and the infusion rate was adjusted to maintain the target sedation goal every 2 h and the hemodynamic，respiratory and sedative parameters were recorded simultaneously.The oxygenation index were measured at 12 and 24 h.The infusion were ceased after 24 h,then the sedative degree was assessed every 30 min until MAAS ≥3 and the recover time were recorded.Results There were no significant differences in blood pressure，oxygenation index and adjustive frequency of drugs between the two groups (all Pgt;0.05).The heart rate，respiratory rate and airway pressure in group M+F decreased significantly than those in Group M (Plt;0.05).The amount of midazolam used and cost of sedatives were lower than those in group M (Plt;0.05).Satisfactory degree of sedation or ventilator synchrony and awakeness score of ATICE in group M+F were higher than those in group M.The recover time was shorter in groupM+F (Plt;0.05).Conclusion In medical ventilated patients, fentanyl improves the sedative effect of midazolam and reduces the dose of midazolam,hence,reduce the total cost of sedatives.
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 study the effects of hyperoxia on ventilator-induced lung injury（VILI） in rats.Methods 48 healthy male SD rats were randomly divided into four groups：Group A received conventional mechanical ventilation（VT=8 mL/kg） with room air，Group B received the same tidal volume as group A with 100% O2，Group C received large tidal volume（VT=40 mL/kg） with room air，group D received the same tidal volume as group C with 100% O2.Arterial blood gases were measured every one hour and oxygenation index（PaO2/FiO2） was calculated.The changes of lung histopathology were assessed by HE staining and observed under light microscope.Wet-to-dry weight ratio（W/D） of left lung，neutrophils and white blood cell（WBC） counts in BALF were measured.TNF-α，IL-1β，and MIP-2 levels in BALF，malondialdehyde（MDA），myeloperoxidase（MPO），and superoxide dismutase（SOD） levels in the lung were assayed，respectively.Results Compared with the Group C，the Group D demonstrated more infiltrating neutrophils in the lung and more destructive changes in the alveolar wall.Meanwhile，the oxygenation index decreased，the WBC and neutrophils counts in BALF increased，and the W/D of left lung was higher in the Group D with significant differences compared with the Group C.Moreover，the BALF levels of TNF-α，IL-1β and MIP-2，the lung levels of MDA increased，and the lung levels of SOD decreased significantly in the Group D compared with those in the Group C.There were no statistical significant differences between the Group B and Group A in all parameters except that MDA levels increased and SOD levels decreased significantly in the Group B.Conclusion Hyperoxia can increase lung injury induced in large tidal volume ventilation in rats，but has mininmal effects in conventional mechanical ventilation.
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 effects of mechanical ventilation on lung pathology and concentration of proinflammatory cytokines in rats.Methods Forty-five healthy Sprague-Dawley rats were randomly divided into three groups with 15 rats each group，ie.a control group(No mechanical ventilation)，a high tidal volume group(VT 34 mL/kg，RR 30 bpm) and low tidal volume group(VT 8 mL/kg，RR 60 bpm).Results There were enlarged alveolar spaces，interalveolar septum collapse，swollen and spotty hemorrhages，inflammatory cell infiltration in the ventilation groups，which was more serious in the high tidal volume group.Lung wet-to-dry weight ratio of high tidal volume group was significantly higher than that of other groups（both Plt;0.05）.The concentrations in both macrophage-inflammatory protein-2（MIP-2）and tumor necrosis factor-α(TNF-α) of bronchoalveolar lavage fluid(BALF) and blood samples was significantly higher in two ventilation groups than the control group（Plt;0.05），which were higer in the high tidal volume group than in the low tidal volume group（Plt;0.05）.Conclusions These results indicate that mechanical ventilation can cause lung injury，which is more serious in high tidal volume ventilation.And mechanical ventilation-induced lung injury can cause proinflammatory cytokines release，with different levels in bronchoalveolar lavage fluid and blood samples.
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.
Sepsis 已经成为危重症医学中较为常见的一种综合征，它定义为因病原体感染而引起的全身性炎症反应综合征。严重Sepsis患者预后不佳，治疗上也较为困难，特别是合并Septic Shock和多器官功能不全综合征（MODS）的患者，死亡率仍然较高，因此近年来在临床及研究上均已引起明显的重视。为了能促进Sepsis的研究及治疗，国际上多个医学专科分会联合发起“拯救Sepsis运动（Surviving Sepsis Campaign, SSC）”，并于2004年首次发表了相应的指南，即Surviving Sepsis Campaign Guideline for Management of Severe Sepsis and Septic Shock。今年初SSC再次发表了新版的指南，主要是结合近年的研究成果而在原版的基础上进行适当的补充和更新，以指导临床上严重Sepsis的抢救及治疗。
Objective To evaluate the effects of different inspiratory flow waveforms on the respiratory function of patients with severe exacerbation of asthma during mechanical ventilation. Methods Twenty-one patients with severe exacerbation of asthma were ventilated with square waveform and decelerating waveform respectively for 30 minutes when the tidal volume was set at 6 mL/ kg, 8 mL/ kg and 10 mL/ kg in ICUof Zhejiang Hospital of Integrated Traditional Chinese and Western Medicine fromJanuary 2006 to December 2007. Meanwhile shunt fraction ( Q·S /Q·T ) , dead space value ( VD/VT ) , airway peak pressure ( Ppeak ) , plateau pressure ( Pplat) ,intrinsic positive end-expiratory pressure( PEEPi) and arterial blood gas analysis were measured. Results The Q ·S /Q·T in the decelerating waveformgroup was less than that of the square waveform group( P lt;0. 05) when tidal volume was set at 6 mL/ kg. When tidal volume was set at 10 mL/ kg, PEEPi and VD /VT in the decelerating waveform group were higher than those of the square waveform group. On the contrary, the Ppeak was lower than that of square waveform group( P lt; 0. 05) . Conclusion For patients with severe exacerbation of asthma treated with mechanical ventilation, decelerating waveform is preferable at low tidal volume( 6 mL/ kg) , and square waveform is preferable at high tidal volume( 10 mL/kg) .
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 assess the risk factors associated with extubation failure in patients who had successfully passed a spontaneous breathing trial.Methods Patients receiving invasive mechanical ventilation for over 48 h were enrolled in the study，they were admitted into Emergency ICU of Zhongshan Hospital during May 2006 and Oct.2007.A spontaneous breathing trial was conducted by a pressure support of 7 cm H2O for 30 min.Clinical data were prospectively recorded for the patient receiving full ventilatory support before and after the spontaneous breathing trial.Regarding the extubation outcome，patients were divived into extubation success group and extubation failure group.Results A total of 58 patients with a mean（±SD） age of 69.4±12.7 years passed spontaneous breathing trial and were extubated.Extubation failure occurred in 11 patients（19%）.The univariate analysis indicated the following associations with extubation failure：elderly patients（78.1±7.9 years vs 67.4±15.1years，Plt;0.05），higher rapid shallow breathing index（RSBI） value（83±12 breaths·min-1·L-1 vs 68±19 breaths·min-1·L-1，Plt;0.05）and excessive respiratory tract secretions（54.5％ vs 21.3％，Plt;0.05）.Conclusion Among routinely measured clinical variables，elderly patients，higher RSBI value and amount of respiratory tract secretions were the valuable index for predicting extubation failure despite a successful spontaneous breathing trial.