Forty critical patients with respiratory failure in the intensive care unit were randomly divided into two groups,Group A with administration of parenteral nutritino(PN) and Group B,no parenteral nutrition given.Blood gas analysis and respiratory monitoring showed that the respiratory rate,pH、PaO2、PaCO2 and HCO3- had no marked difference between the two groups.But in Group A there was a slight decrease of Pao2/FiO2 and a marked increase of A-aDO2 and the pulmonary shunt.This study indicates that the content of fat emulsion and hydrocarbon in PN may be the main factor that affects the respiratory function.
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 effect of noninvasive positive pressure ventilation (NPPV) in chronic obstructive pulmonary disease (COPD) patients with hypercapnic coma secondary to respiratory failure.Methods COPD patients with or without coma secondary to respiratory failure were both treated by bi-level positive airway pressure (BiPAP) ventilation on base of routine therapy.There were 32 cases in coma group and 42 cases in non-coma group.Such parameters as arterial blood gas (ABG)，Glasgow coma scale (GCS)，time of NPPV therapy，achievement ratio，and adverse effects were investigated.Results 30 patients in the coma group were improved after NPPV treatment (26 cases recovered consciousness treated by BiPAP in 2 hours，3 cases recovered between 3~8 hours，1 case recovered after 24 hours).The parameters of ABG，the tidal volume and the minute ventilation volume were improved after BiPAP.The time of effective therapy was (9±4) days in the coma group and (7±3) days in the non-coma group with no significant difference (Pgt;0.05).The achievement ratio was similar in two groups (93.75% vs 97.62%，Pgt;0.05).But the incidence of gastrointestinal tympanites reached to a higher level in the coma group (80.5%) than the non-coma group (10.6%).Conclusion COPD patients with hypercapnic coma secondary to respiratory failure isn’t the absolute contraindication of NPPV treatment.
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 exogenous pulmonary surfactant （PS） on ventilation weaning and respiratory mechanics in infants with acute lung injury（ALI） after cardiopulmonary bypass （CPB）.Methods Twelve infants underwent cardiopulmonary bypass cardiac surgery committed with ALI and difficulty in weaning from ventilation were included in this study.Exogenous PS was used in the treatment via intra-tracheal administration.The changes of blood gas，respiratory mechanics and the conditions of ventilation weaning were observed.Results After intra-tracheal PS administration，spontaneous breath remained steady；spontaneous respiratory rate significantly decreased from，tidal volume of spontaneous breath increased significantly.Three concave sign disappeared and koilosternia was alleviated.PaCO2 value decreased significantly and peak inspiratory pressure（PIP） decreased from （36.18±10.25）cm H2O to （25.11±5.14）cm H2O （Plt;0.01）.Static lung compliance （Cstat） increased from （1.49±0.65）mL·cm H2O-1·kg-1 before treatment to （1.95±0.50） mL·cm H2O-1·kg-1 6 h after treatment （Plt;0.01）；and airway resistance （Rstat）decreased from （128.17±26.34） cm H2O·L-1·s-1 before treatment to （78.56±18.22） cm H2O·L-1·s-1 6 h after treatment （Plt;0.01）.All 12 infants weaned from ventilator successfully.Conclusion Combined with PS intra-tracheal treatment，lung protective ventilation strategy can significantly improve parameters of respiratory mechanics，increase dynamic lung compliance，decrease airway resistance，which can decrease the breathing effort of the infants and make it easy to wean from ventilator.
Objective To compare the systematic and lung pharmacokinetic parameters of moxifloxacin hydrochloride and explore a feasible tool to monitor drug concentration and evaluate therapeutic efficacy of respiratory fluoroquinolones. Methods Ten adult patients with community-acquired pneumonia or acute exacerbation of chronic bronchitis were enrolled.The subjects received a single dose of oral moxifloxacin hydrochloride 400 mg. Serum specimens were sampled at 0，1，2，3，4，8，24 h and sputum specimens were collected 0，1，2，4，8，20，24 h after administration，respectively.The serum and sputum concentrations of moxifloxacin hydrochloride were assayed by means of high-performance liquid chromatography. Standard pharmacokinetic parameters including peak concentrations(Cmax) and area under the concentration-time curve (AUC0-24 h) were assessed. Results Serum C(max) was（5.95±1.35）mg/L at 2 hours and serum AUC0-24 h was (58.72±8.11）mg·h-1·L-1 while sputum Cmax and AUC0-24 h were （16.18±6.47）mg/L at 3 hours and （138.04±78.29）mg·h-1·L-1 respectively，which were significantly higher than those in serum. Conclusion Oral administration of moxifloxacin hydrochloride to patients with respiratory infections results in rapid penetration into lung and maintain a one-fold drug concentration compared to blood concentration within 24 hours.Sputum drug concentration analysis demonstrates a superior pharmacokinetic profile of moxifloxacin in respiratory tract.
Objective To explore the effect of budesonide nebulization in the treatment of mechanically ventilated patients with chronic obstructive pulmonary disease(COPD).Methods A total of 25 intubated and ventilated COPD patients complicated with respiratory failure was randomly divided into two groups.The control group consisted of 12 patients received salbutamol nebulization on the routine treatment.The budesonide group consisted of 13 patients received budesonide plus salbutamol nebulization on the routine treatment.Variables such as tumor necrosis factor-α(TNF-α) and interleukin-8(IL-8) in the bronchoalveolar lavage fluid(BALF) ， incidence of ventilation-associated lung injury(VALI) ， days of mechanical ventilation ，， days of hospitalization and survival rate were measured and compared.Results The survival rate and incidence of VALI were not different significantly between the two groups.However ， the levels of TNF-α and IL-8 in BALF of the control patients were significantly lower than those in the budesonide group[ （ 1.2±0.2 ） mg/L vs （ 1.5±0.4 ） mg/L ，（ 85.7±26.5 ）（ 125.6±30.4 ）， both Plt;0.05).And the days of mechanical ventilation and hospitalization were statistically shorter in the budesonide group compared with the control group[ (7.2±2.5 ） d vs （ 10.5±6.2 ） d ， (10.5±4.7 ） d vs (15.8±6.6 ） d ， both Plt;0.05].Conclusion Our data suggest that nebulization of budesonide can suppressed the pulmonary inflammation and decreased days of the mechanical ventilation and hospitalization in mechanically ventilated COPD patients.
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 investigate the effect of intra-abdominal hypertension(IAH) on respiratory function in pigs.Methods Twelve pigs were randomly divided into two groups (n=6 in each group),ie.IAH20 group(intra-abdominal pressure=20 mm Hg) and IAH30 group(intra-abdominal pressure=30 mm Hg).Pig model of IAH was established by intraperitoneally injection of carbon dioxide.The changes in respiratory function parameters including pulmonary dynamic compliance（Cdyn），peak inspiratory pressure(PIP) ,SpO2 and PaCO2 were recorded at different time points.Results Cdyn was significantly decreased at different time points compared with baseline in group IAH30 and group IAH20.PIP significantly increased at different time points compared with baseline in both IAH groups，but group IAH30 was more severe than group IAH20. No significant changes of SpO2 and PaCO2 were found in two IAH groups.Conclusion IAH can impair respiratory function by decreasing lung compliance and increasing inspiratory pressure.
Objective To assess the effect of continuous positive airway pressure ( CPAP) on expiratory flow limitation in severe chronic obstructive pulmonary disease ( COPD) patients during noninvasive ventilation by oscillatory reactance ( Xrs ) . Methods Eight patients with stable COPD and chronic hypercapnic respiratory failure( type II) received noninvasive ventilation with a traditional CPAP ventilator through a nasal mask were enrolled. The CPAP were successively set as 4, 8 and 12 cm H2O respectively. The forecd oscillation( 5 Hz, 2 cm H2O) was imposed into the mask and the flow and nasal pressure were measured at the airway opening. The difference between inspiratory and expiratory Xrs( ΔXrs)were calculated for each breathing cycle and average ΔXrs was calculated at different pressure levels according to the established algorithm. Meanwhile, the oesophageal pressure was also measured by a balloontipped catheter and transpulmonary pressure was calculated. The breathing cycles above were analyzed subsequently and classified as expiratory flow-limited( EFL) and non-EFL breath. In addition, flow and nasal pressure when breathing naturally( CPAP = 0 cmH2O) was also collected for each patient and the EFL breath cycles was identified as baseline. Then, the percentage of EFL breathing cycles and ΔXrs were calculated for each CPAP level and their relationship was analyzed. The threshold value of ΔXrs with maximum sensitivity and specificity to detect EFL and the optimal CPAP to suppress the development of EFL were computed. Results ①CPAP increased from4 to 8 and 12 cm H2O resulted in fall of mean values of ΔXrs from2. 67 to 1. 62 and 1. 31 cm H2O· s- 1 · L- 1 , respectively( ΔXrs at CPAP 0 cm H2O was not detected) , and the decrease of ΔXrs when CPAP up to 8 cm H2O from 4 cm H2 O was significant ( Z = - 2. 68, P = 0. 01) . ②CPAP significantly suppressed the development of EFL, when CPAP increased from0 cm H2O to 4,8 and12 cmH2O resulted in decrease in the percentage of breathing cycle from 29. 8% to 9. 9% , 8. 1% and 4. 4%, respectively( 2 = 15. 6, P = 0. 01) . ③ ΔXrs was related to the degree of EFL and the mean value of ΔXrs in EFL breathing cycles was significantly higher than that in non-EFL’s. When ΔXrs decreased to 1. 83 cm H2O· s- 1 · L- 1, the majority of breath showed non-EFL, with a sensitivity of 94% and specificity of 97% for detecting EFL, respectively. Conclusions ΔXrs is an indicator of the occurrence of EFL. Appropriate CPAP to render the value of ΔXrs equal to or slightly less than 1. 83 cm H2O·s - 1 ·L- 1 may effectively suppress the development of EFL in severe COPD patients during noninvasive ventilation.