Objective To investigate the application of sequential noninvasive ventilation (NIV) in weaning patients off mechanical ventilation after coronary artery bypass grafting (CABG). Methods From July 2007 to July 2009, 52 patients who underwent CABG with mechanical ventilation for no less than 24 hours and P/F Ratio lower than 150 mm Hg were divided into two groups with random number table. In the sequential NIV group (SNIV group), there were 19 patients including 16 males and 3 females whose ages were 69.26±8.10 years. In the prolonged mechanical ventilation group (PMV group), there were 33 patients including 28 males and 5 females whose ages were 70.06±7.09 years. Clinical data of these two groups were compared and the influence of NIV on the circulation and respiration of the patients were observed. Results The SNIV group weaned off mechanical ventilation earlier than the PMV group (26.46±3.66 h vs. 38.65±9.12 h, P=0.013). The SNIV group held shorter total ventilation time (29.26±21.56 h vs.54.45±86.57 h,P=0.016), ICU stay time (2.44±2.99 d vs. 4.89±7.42 d, P=0.028) and postoperative hospital time (10.82±4.31 d vs. 14.01±19.30 d, P=0.039) than the PMV group. Furthermore, the SNIV group had lower pneumonia rate (5.26% vs. 30.30%, P=0.033) and total postoperative complication rate (10.53% vs.45.45%, P=0.030) than the PMV group. However, there was no significant difference (Pgt;0.05) between the two groups in the successful weaning rate, repeated tracheal intubation rate, tracheotomy rate and mortality 30 days after operation. After NIV, SNIV group had no significant change in heart rate, central vein 〖CM(1585mm〗pressure, pulmonary arterial pressure and pulmonary arterial wedge pressure than the baseline value, while systolic pressure (129.66±19.11 mm Hg vs. 119.01±20.31 mm Hg, P=0.031), cardiacindex ［3.01±0.30 L/(min.m2) vs. 2.78±0.36 L/(min.m2), P=0.043］ and P/F Ratio (205.95±27.40 mm Hg vs. 141.33±9.98 mm Hg, P=0.001) were obviously elevated. Conclusion Sequential NIV is a effective and safe method to wean CABG patients off mechanical ventilation.
Objective To observe the effects of penehyclidine hydrochloride ( PHCD) combined with mechanical ventilation ( MV) on inflammatory response in rats with ARDS induced by oleic acid ( OA) .Methods The rat ARDS model was established by OA via intravenous injection ( iv) . 32 adult healthy male SD rats were randomly divided into four groups, ie. a normal control group( group C: intra-peritoneal injection of a same amount of normal saline and intravenous injection of a same amount of normal saline respectively rather than PHCD) , a model group( group A1) , a PHCD group ( group A2: intra-peritoneal injection of 0. 5 mg/kg PHCD30 minutes before OA iv) and a PHCD+MV group ( group A3: VT = 4 mL/kg,respiratory rate =70 beats /min, I∶E =1∶2, FiO2 =21%) . Four hours after OA iv, arterial partial pressure of oxygen ( PaO2 ) was measured, and the oxygenation index ( PaO2 /FiO2 ) as well as wet /dry weight ratio( W/D) of lung tissue were calculated respectively. The pathological changes of lung tissue was observed through light microspcope. Interlukin-8 ( IL-8 ) , myeloperoxidase ( MPO) and NF-κB in lung tissue homogenate were measured by enzyme linked immunosorbent assay ( ELISA ) . Results Extensive pneumonedema, pneumorrhagia, focal atelectasis and amout of inflammatory cells infiltration in lung tissues were all revealed in ARDS rats. Lung injury score ( 8. 63 ±2. 20 vs. 1. 38 ±0. 92) , W/D ratio ( 8. 37 ±0. 99 vs. 4. 08 ±0. 65) were all higher in the ARDS rats than those in group C( all P lt;0. 01) . PaO2 /FiO2 was lower in group A1 than that in group C [ ( 206 ±32) mm Hg vs. ( 428 ±28) mm Hg, P lt; 0. 01] . The concentrations of MPO [ ( 33. 91 ±1. 43) ng/mL vs. ( 20. 92 ±1. 40) ng/mL) ] , IL-8 [ ( 809 ±39) ng/L vs. ( 583 ±91) ng/L] and NF-κB [ ( 1163 ±105) ng/L vs. ( 803 ±130) ng/L] in lung tissue homogenate were significantly increased in the ARDS rats than those in group C ( all P lt;0. 01) . Pathological changes of lung tissue ( including pneumonedema, pneumorrhagia, atelectasis and inflammatory cell infiltration, etc. )obviously improved when treated by PHCD or/and PHCD combined with MV ( all P lt;0. 05) . PaO2 /FiO2 in group A2 and A3 were both significantly increased when compared with group A1 ( both P lt; 0. 05) .Meanwhile,W/D ratio, lung injury score, and concentrations of MOP, IL-8 and NF-κB were sharply decreased in group A2 and A3 ( all P lt;0. 05) . The improvement in all above indices were more significant in group A3 than those in group A2, despite all those indices failed to meet the levels of normal rats ( all P lt; 0. 05) .Conclusion PHCD can inhibit the inflammatory response in ARDS rats induced by OA iv, through which it protect the lung tissue frominjury induced by OA. The protective role of PHCD plus MV is superior to that of PHCD only.
Objective To observe the level of vascular endothelium growth factor A( VEGF-A) in exhaled breath condensate ( EBC) of patients with acute lung injury/acute respiratory distress syndrome ( ALI/ARDS) , and investigate its clinical significance. Methods EBC of 23 patients with ALI/ARDS by mechanical ventilation in intensive care unit ( ICU) were collected with improved EcoScreen condenser. EBC of 17 normal control subjects were collected with EcoScreen condensor. The level of VEGF-A was measured by ELISA in EBC and serum. The levels of VEGF-A in EBC of patients with different grades of lung injuries were compared, and the correlation was analyzed between the level of VEGF-A and clinical indicators. Results The level of VEGF-A in EBC was lower in the patients with ALI/ARDS than that of control subjects [ ( 49. 88 ±6. 32) ng/L vs. ( 56. 50 ±6. 323) ng/L, P lt;0. 01] , the level of VEGF-A was higher in the ALI patients than that of ARDS patients [ ( 53. 56 ±5. 56) ng/L vs. ( 45. 86 ±4. 45) ng/L, P lt;0. 01] ,and higher in the survival patients than that of the died patients [ ( 51. 92 ±6. 28) ng/L vs. ( 46. 05 ± 4. 58) ng/L, P lt;0. 05] . The level of VEGF-A in EBC was negatively correlated with lung injury score and A-aDO2 /PaO2 ( r = - 0. 426 and - 0. 510, respectively, P lt;0. 05) , and positively correlated with PaO2 /FiO2 and PaO2 ( r =0. 626 and 0. 655, respectively, P lt; 0. 05) . The level of VEGF-A in serum was not different between the ALI/ARDS patients and the control subjects, between the ALI and ARDS patients, or between the survival and the died patients ( all P gt;0. 05) . The level of VEGF-A in serumhad no correlation with lung injury score, A-aDO2 /PaO2 , PaO2 /FiO2 , or PaO2 ( all P gt;0. 05) . Conclusion The changes of VEGF-A in EBC of patients with ALI/ARDSmay serve as an indicator for severity and prognosis evaluation.
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 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 We investigated the effect of supplementation with alanyl-glutamine dipeptide on insulin resistance and outcome in patients with chronic obstructive pulmonary disease (COPD) and respiratory failure. Methods A prospective, randomized, open and controlled trial was conducted. Patients with COPD and respiratory failure were recruited between Jan 2005 to Feb 2006 and randomly assigned to a trial group (n=14) with glutamine dipeptide supplmented parenteral nutrition and a control group (n=16) with isocaloric, isonitrogenic parenteral nutrition. On the third day and fifth day of nutrition treatment, blood glucose was clamped at level of 4.4 to 6.1 mmol/L by intravenously bumped insulin. Blood gas, blood glucose level, insulin dosage were recorded everyday. The outcomes were mortality, length of stay (LOS) in hospital and in ICU, mechanical ventilation times and the costs of ICU and hospital.Results Thirty patients successfully completed the trial. There was no difference in blood gas between two groups, but PaO2 increased gradually. Compared with control group, blood glucose level had trend to decrease in trial group. The average insul in consumption decreased significantly in trial group on the fifth day. There was no statistical difference between two groups in mortality, length of stay in hospital and the costs of hospital. But compared with control group, length of stay in ICU and mechanical ventilation days had trend to decrease in trial group. Conclusion Alanyl-glutamine dipeptide do not improve pulmonary function of patients with COPD and respiratory failure. However, alanyl-glutamine dipeptide attenuated insul in resistance and stabilized blood glucose. This trial does not confirm alanyl-glutamine di peptide can improve outcome in critically ill patients with COPD and respiratory failure between two groups in mortality at the end of 30 days, length of stay in hospital and the costs of hospital. But the length of stay in ICU and the duration of mechanical ventilation does decrease, but not significantly, in the trial group.
ObjectiveTo estimate whether alpha 1-antitrypsin (AAT) can reduce ventilator-induced lung injury (VILI) in acute respiratory distress syndrome (ARDS) rats after mechanical ventilation.MethodsThe rats were randomly divided into 3 groups: a sham (S) group, a mechanical ventilation (V) group and a mechanical ventilation/AAT (VA) group. The rats in the S group only received anesthesia, and the rats in the V and VA groups received endotoxin to simulate ARDS followed by mechanical ventilation for 4 hours. At the beginning of ventilation, the rats in the V group received saline, and the rats in the VA group received AAT. The PaO2/FiO2 ratio and the lung wet/dry (W/D) weight ratio were tested. The total protein and neutrophil elastase concentrations and the neutrophil and macrophage counts in bronchoalveolar lavage fluid (BALF) were tested. Proinflammatory factors in BALF and intercellular cell adhesion molecule-1 (ICAM-1) and microphage inflammatoryprotein-2 (MIP-2) in the serum were also detected. Furthermore, the oxidative stress response was detected, and histological injury and apoptosis were evaluated.ResultsCompared with the S group, PaO2/FiO2 was significantly decreased in the V group and the VA group, the protein concentration in the BALF and the lung W/D weight ratio were significantly increased, the concentration of inflammatory factors in BALF and peripheral blood was significantly increased, and inflammatory cells in BALF also increased. Meanwhile, malondialdehyde (MDA) concentration, myeloperoxidase (MPO) and nicotinamide adeninedinucleotide phosphate (NADPH) activity increased significantly. The V group and VA group were severely damaged, and the number of apoptotic cells increased significantly. Compared with the V group, the PaO2/FiO2 in the VA group significantly increased; the W/D weight ratio and the BALF protein concentration decreased; the number of macrophages and neutrophils in the BALF, and the concentration of elastase significantly decreased; tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 in BALF decreased, IL-10 increased; ICAM-1 and MIP-2 in peripheral blood decreased. At the same time, the MDA concentration, MPO and NADPH activities in the VA group were significantly lower than those in the V group; the tissue damage was significantly reduced, and the number of apoptosis was significantly reduced. In addition, compared with the V group, the expression of Bax, gelsolin and cleaved caspase-3 decreased in the VA group, but the expression of Bcl-2 was increased (all P<0.05).ConclusionsAAT can relieve VILI in ARDS rats. The protection conferred by AAT may be associated with the anti-inflammatory, antioxidative stress response and antiapoptotic effect of AAT.
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.
ObjectiveTo explore the applicability of early goal-directed sedation (EGDS) in intensive care unit (ICU) patients with mechanical ventilation.MethodsAn prospective double blind study was conducted. ICU patients with mechanical ventilation in the First Affiliated Hospital of Jinzhou Medical University were recruited as research objects by chester sampling from September 2015 to September 2017, and divided into an experimental group and a control group by stratified randomization. Two groups were sedated on the basis of adequate analgesia. The experimental group adopted the EGDS strategy that dexmedetomidin was the first choice to be infused at the rate of 1 μg·kg–1·h–1. And the patients were given Richmond agitation-sedation score (RASS) on the interval of 4 hours: used additionally propofol and midazolam if RASS>2, or reduced right metomomidin at the speed of 0.2 μg·kg–1·h–1 per 30 min if RASS<–3, and stopped sedation until RASS of –2 to 0. The control group adopted routine sedation strategy that propofol was the first choice to be infused and combined with dexmedetomidine and midazolam until RASS score in –2 to –3. The doses of sedative drugs, mechanical ventilation time, ICU-stayed time, total hospitalization time and the incidence of adverse events such as delirium, accidental extubation, and ICU death were compared between two groups.ResultsSixty-sis cases were selected in the experimental group and 71 in the control group. The baseline data such as gender, age, acute physiology chronic health evaluation Ⅱ (APACHEⅡ), or basic diseases in two groups had no significant differences. Compared with the control group, the per capita total doses of dexmedetomidine, propofol and midazolam in the experimental group were significantly less [right metopromicine (μg): 154.45±27.86 vs. 378.85±39.76; propofol (mg): 4 490.03±479.88 vs. 7 349.76±814.31; midazolam (mg): 255.38±46.24 vs. 562.79±97.26; all P<0.01], mechanical ventilation time, ICU-stayed time, total hospitalization time were significantly lower [mechanical ventilation time (d): 7.7±3.3vs. 11.7±3.6; ICU-stayed time (d): 10.2±3.9 vs. 19.2±4.1, total hospitalization time (d): 29.9±4.6 vs. 50.4±9.1; all P<0.01]. The Kaplan-Meier survival curves showed that the incidence of delirium in the experimental group was significantly lower than that in the control group (log-rankχ2=5.481, P<0.05). The accidental extubation rate and accidental fatality rate in two groups had no significant differences (log-rankχ2=0.078, 0.999, P>0.05).ConclusionEGDS can not only reduce the dose of sedative drugs, shorten the mechanical ventilation time, the ICU-stayed time and the total hospitalization time, but also reduce the incidence of delirium, so it has a positive impact in ICU patients with mechanical ventilation.
Objective To evaluate the influence of tidal volume on the accuracy of stroke volume variation ( SVV) to predict volume state of pigs with ventilation.Methods Thirty-six healthy pigs were anesthetized after tracheal intubation and ventilated. With the envelope method, they were randomized into a normovolemia group, a hemaerrhagic shock group, and a hypervolemia group, with 12 pigs in each group. The pigs in the hemaerrhagic shock group were removed 20 percent of blood, and the pigs in the hypervolemia group received additional infusion of 20 percent 6% hydroxyethyl starch. In each group, ventilator settings were changed in a randomized order by changing VT [ VT = 5 mL/kg ( VT5 ) , VT =10 mL/kg ( VT10 ) , and VT =15 mL/kg ( VT15 ) ] . Hemodynamic measurements [ heart rate ( HR) , mean arterial boold pressure ( MAP) , systemic vascular resistance index ( SVRI) , cardiac index ( CI) , stroke volume index ( SVI) , intrathoracic blood volume index( ITBVI) , and SVV] were obtained after 10 minutes of stabilization. Results SVV was increased in the hemaerrhagic shock group comparing with the normovolemia group for VT10 [ ( 21 ±5) % vs. ( 11 ±2) % , P lt;0. 05] , but SVV was decreased in the hypervolemia group comparing with the normovolemia group [ ( 7 ±2) % vs. ( 11 ±2) % , P lt; 0. 05] . The variation tendency for VT15 was the same with VT10 , moreover SVV were all above 12% for the hemaerrhagic shock group, the normovolemia group, and the hypervolemia group [ ( 30 ±7) % , ( 19 ±3) % , and ( 15 ±4) % ] . There were no significant diffrences among the hemaerrhagic shock group, hypervolemia group and normovolemia group [ ( 8 ±6) % ,( 7 ±5) % , and ( 7 ±4) % , P gt; 0. 05] for VT5 . Conclusions SVV was a precise indicator of cardiac preload, but SVV was less sensitive to the changes of volume during low tidal volume ( 5 mL/kg) ventilation. The threshold of SVV for predicting fluid responsiveness maybe above 12% with a high tidal volume ( 15 mL/kg) ventilation.
