ABSTRACT
BACKGROUND@#Acinetobacter baumannii (A. baumannii) has become one of the most important opportunistic pathogens inducing nosocomial pneumonia and increasing mortality in critically ill patients recently. The interaction between A. baumannii infection and immune response can influence the prognosis of A. baumannii related pneumonia. The target of the present study was to investigate the role of immunodeficiency in A. baumannii induced pneumonia.@*METHODS@#Male BALB/c mice were randomly divided into the normal immunity control (NIC) group, normal immunity infection (NIA) group, immune compromised control (CIC) group, and immune compromised infection (CIA) group (n = 15 for each group). Intraperitoneal injection of cyclophosphamide and intranasal instillation of A. baumannii solution were used to induce compromised immunity and murine pneumonia, respectively. The mice were sacrificed at 6 and 24 h later and the specimens were collected for further tests. Seven-day mortality of mice was also assessed.@*RESULTS@#After A. baumannii stimulation, the recruitment of neutrophils in mice with normal immunity increased sharply (P = 0.030 at 6 h), while there was no significant raise of neutrophil counts in mice with compromised immune condition (P = 0.092 at 6 h, P = 0.772 at 24 h). The Th cell polarization presented with pulmonary interleukin (IL)-4 and interferon (IFN)-γ level in response to the A. baumannii in CIA group were significantly depressed in comparison with in NIA group (IFN-γ: P = 0.003 at 6 h; P = 0.001 at 24 h; IL-4: P < 0.001 at 6 h; P < 0.001 at 24 h). The pulmonary conventional dendritic cell accumulation was even found to be inhibited after A. baumannii infection in immunocompromised mice (P = 0.033). Correspondingly, A. baumannii associated pneumonia in mice with compromised immunity caused more early stage death, more severe histopathological impairment in lung.@*CONCLUSION@#A. baumannii could frustrate the immune response in immunocompromised conditions, and this reduced immune response is related to more severe lung injury and worse outcome in A. baumannii induced pneumonia.
ABSTRACT
Background@#Although the use of extra-corporeal membrane oxygenation (ECMO) has been rapidly increasing, the benefit of ECMO in patients with acute respiratory distress syndrome (ARDS) remains unclear. Our objective was to investigate the effect of venovenous ECMO (VV-ECMO) on adult patients with severe ARDS.@*Methods@#We conducted a multi-center, retrospective, cohort study in the intensive care units (ICUs) of six teaching hospitals between January 2013 and December 2018. Patients with severe ARDS who received VV-ECMO support were included. The detailed demographic data and physiologic data were used to match ARDS patients without ECMO. The primary endpoint was the 28-day mortality.@*Results@#Ninety-nine patients with severe ARDS supported by VV-ECMO and 72 patients without ECMO were included in this study. The acute physiology and chronic health evaluation II score was 23.1 ± 6.3 in the ECMO group and 24.8 ± 8.5 in the control group (P = 0.1195). The sequential organ failure assessment score was 12.8 ± 3.4 in the ECMO group and 13.7 ± 3.5 in the control group (P = 0.0848). The 28-day mortality of patients with ECMO support was 39.4%, and that of the control group was 55.6%. The survival analysis curve showed that the 28-day mortality in the ECMO group was significantly lower than that in the control group (P = 0.0097). Multivariate Cox regression analysis showed that the independent predictors of the 28-day mortality were the requirement of vasopressors before ECMO (hazard ratio [HR]: 1.006; 95% confidence interval [CI]: 1.001–1.013; P = 0.030) and duration of mechanical ventilation before ECMO (HR: 3.299; 95% CI: 1.264–8.609; P = 0.034).@*Conclusions@#This study showed that ECMO improved the survival of patients with severe ARDS. The duration of mechanical ventilation and the requirement of vasopressors before ECMO might be associated with an increased risk of death.
ABSTRACT
BACKGROUND@#Although the use of extra-corporeal membrane oxygenation (ECMO) has been rapidly increasing, the benefit of ECMO in patients with acute respiratory distress syndrome (ARDS) remains unclear. Our objective was to investigate the effect of venovenous ECMO (VV-ECMO) on adult patients with severe ARDS.@*METHODS@#We conducted a multi-center, retrospective, cohort study in the intensive care units (ICUs) of six teaching hospitals between January 2013 and December 2018. Patients with severe ARDS who received VV-ECMO support were included. The detailed demographic data and physiologic data were used to match ARDS patients without ECMO. The primary endpoint was the 28-day mortality.@*RESULTS@#Ninety-nine patients with severe ARDS supported by VV-ECMO and 72 patients without ECMO were included in this study. The acute physiology and chronic health evaluation II score was 23.1 ± 6.3 in the ECMO group and 24.8 ± 8.5 in the control group (P = 0.1195). The sequential organ failure assessment score was 12.8 ± 3.4 in the ECMO group and 13.7 ± 3.5 in the control group (P = 0.0848). The 28-day mortality of patients with ECMO support was 39.4%, and that of the control group was 55.6%. The survival analysis curve showed that the 28-day mortality in the ECMO group was significantly lower than that in the control group (P = 0.0097). Multivariate Cox regression analysis showed that the independent predictors of the 28-day mortality were the requirement of vasopressors before ECMO (hazard ratio [HR]: 1.006; 95% confidence interval [CI]: 1.001-1.013; P = 0.030) and duration of mechanical ventilation before ECMO (HR: 3.299; 95% CI: 1.264-8.609; P = 0.034).@*CONCLUSIONS@#This study showed that ECMO improved the survival of patients with severe ARDS. The duration of mechanical ventilation and the requirement of vasopressors before ECMO might be associated with an increased risk of death.
ABSTRACT
<p><b>BACKGROUND</b>Propofol is increasingly used during partial support mechanical ventilation such as pressure support ventilation (PSV) in postoperative patients. However, breathing pattern, respiratory drive, and patient-ventilator synchrony are affected by the sedative used and the sedation depth. The present study aimed to evaluate the physiologic effects of varying depths of propofol sedation on respiratory drive and patient-ventilator synchrony during PSV in postoperative patients.</p><p><b>METHODS</b>Eight postoperative patients receiving PSV for <24 h were enrolled. Propofol was administered to achieve and maintain a Ramsay score of 4, and the inspiratory pressure support was titrated to obtain a tidal volume (VT) of 6-8 ml/kg. Then, the propofol dose was reduced to achieve and maintain a Ramsay score of 3 and then 2. At each Ramsay level, the patient underwent 30-min trials of PSV. We measured the electrical activity of the diaphragm, flow, airway pressure, neuro-ventilatory efficiency (NVE), and patient-ventilator synchrony.</p><p><b>RESULTS</b>Increasing the depth of sedation reduced the peak and mean electrical activity of the diaphragm, which suggested a decrease in respiratory drive, while VT remained unchanged. The NVE increased with an increase in the depth of sedation. Minute ventilation and inspiratory duty cycle decreased with an increase in the depth of sedation, but this only achieved statistical significance between Ramsay 2 and both Ramsay 4 and 3 (P < 0.05). The ineffective triggering index increased with increasing sedation depth (9.5 ± 4.0%, 6.7 ± 2.0%, and 4.2 ± 2.1% for Ramsay 4, 3, and 2, respectively) and achieved statistical significance between each pair of depth of sedation (P < 0.05). The depth of sedation did not affect gas exchange.</p><p><b>CONCLUSIONS</b>Propofol inhibits respiratory drive and deteriorates patient-ventilator synchrony to the extent that varies with the depth of sedation. Propofol has less effect on breathing pattern and has no effect on VT and gas exchange in postoperative patients with PSV.</p>
Subject(s)
Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Young Adult , Blood Pressure , Physiology , Hemodynamics , Physiology , Intensive Care Units , Positive-Pressure Respiration , Methods , Propofol , Therapeutic Uses , Prospective Studies , Respiration, Artificial , Methods , Tidal Volume , PhysiologyABSTRACT
<p><b>BACKGROUND</b>Early goal-directed therapy (EGDT) has become an important therapeutic management in early salvage stage of septic shock. However, splenic organs possibly remained hypoperfused and hypoxic despite fluid resuscitation. This study aimed to evaluate the effect of EGDT on hepatic perfusion in septic shock patients.</p><p><b>METHODS</b>A prospective observational study was carried out in early septic shock patients who were admitted to Intensive Care Unit within 24 h after onset and who met all four elements of the EGDT criteria after treatment with the standard EGDT procedure within 6 h between December 1, 2012 and November 30, 2013. The hemodynamic data were recorded, and oxygen metabolism and hepatic functions were monitored. An indocyanine green clearance test was applied to detect the hepatic perfusion. The patients' characteristics were compared before treatment (T0), immediately after EGDT (T1), and 24 h after EGDT (T2). This study is registered at ClinicalTrials.org, NCT02060773.</p><p><b>RESULTS</b>Twenty-one patients were included in the study; however, the hepatic perfusion data were not included in the analysis for two patients; therefore, 19 patients were eligible for the study. Hemodynamics data, as monitored by pulse-indicator continuous cardiac output, were obtained from 16 patients. There were no significant differences in indocyanine green plasma disappearance rate (ICG-PDR) and 15-min retention rate (R15) at T0 (11.9 ± 5.0%/min and 20.0 ± 13.2%), T1 (11.4 ± 5.1%/min and 23.6 ± 14.9%), and T2 (11.0 ± 4.5%/min and 23.7 ± 15.3%) (all P > 0.05). Both of the alterations of ICG-PDR and R15 showed no differences at T0, T1, and T2 in the patients of different subgroups that achieved different resuscitation goal numbers when elected (P > 0.05).</p><p><b>CONCLUSION</b>There were no hepatic perfusion improvements after EGDT in the early phase of patients with septic shock.</p><p><b>TRIAL REGISTRATION</b>Clinicaltrials.gov NCT02060773 (https://clinicaltrials.gov/ct2/show/NCT02060773).</p>
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Cardiac Output , Physiology , Disease Management , Fluid Therapy , Hemodynamics , Physiology , Intensive Care Units , Prospective Studies , Shock, Septic , TherapeuticsABSTRACT
<p><b>BACKGROUND</b>Weaning difficulties occur in 31% of total intubated patients, and result in prolonged weaning duration. A computer-driven automated weaning system can perform a spontaneous breathing trial (SBT) automatically and display a message when the trial is successfully passed. Such a system might have a beneficial effect on difficult-to-wean patients. The aim of this study was to examine whether the computer-driven automated weaning system can accelerate discontinuation of mechanical ventilation and improve outcomes in difficult-to-wean patients.</p><p><b>METHODS</b>This randomized controlled study included 39 difficult-to-wean patients who failed their first spontaneous breathing trial. Before initiating weaning, eligible patients were randomly allocated to wean by computer-driven automated weaning system (CDW group, n = 19) or a physician-controlled local protocol (PW group, n = 20). Weaning duration, defined as the time from inclusion until first extubation, was the primary endpoint. Secondary endpoints were total duration of mechanical ventilation, the length of intensive care unit (ICU) stay, the number of reintubations, the mortality rate in the ICU, the number of noninvasive ventilations, the number of complications in the ICU, and the number of ventilator-associated pneumonia cases.</p><p><b>RESULTS</b>The weaning duration was reduced with the computer-driven weaning as compared with the usual protocol (median 29.0 hours vs. 45.5 hours, P = 0.044). Total duration of mechanical ventilation and duration of the ICU stay did not differ between the CDW and PW groups. There was no difference in the number of reintubations between the CDW and PW groups (3 and 4 patients, P = 0.732). The study groups showed comparable numbers of tracheostomy, self-extubations, ventilator-associated pneumonia, and non-invasive ventilation. Mortality in the ICU was similar in the CDW and the PW groups (21.1% vs. 20.0%, P = 0.935).</p><p><b>CONCLUSION</b>The computer-driven automated weaning system can reduce weaning duration in difficult-to-wean patients as compared with a physician-controlled weaning protocol.</p>
Subject(s)
Aged , Female , Humans , Male , Middle Aged , Intensive Care Units , Respiration, Artificial , Methods , Ventilator Weaning , MethodsABSTRACT
<p><b>BACKGROUND</b>Intra-abdominal hypertension (IAH) is common in acute respiratory distress syndrome (ARDS) patients and when resulting in decrease of chest wall compliance will weaken the effect of positive end expiratory pressure (PEEP). We investigated the effect of PEEP titrated by transpulmonary pressure (Ptp) on oxygenation and respiratory mechanics in ARDS patients with IAH compared with PEEP titrated by ARDSnet protocol.</p><p><b>METHODS</b>ARDS patients admitted to the intensive care unit (ICU) of the Zhongda Hospital were enrolled. Patients were ventilated with volume control mode with tidal volume of 6 ml/kg under two different PEEP levels titrated by Ptp method and ARDSnet protocol. Respiratory mechanics, gas exchange and haemodynamics were measured after 30 minutes of ventilation in each round. IAH was defined as intra-abdominal pressure of 12 mmHg or more.</p><p><b>RESULTS</b>Seven ARDS patients with IAH and 8 ARDS patients without IAH were enrolled. PEEP titrated by Ptp were significant higher than PEEP titrated by ARDSnet protocol in both ARDS patients with IAH ((17.3 ± 2.6) cmH2O vs. (6.3 ± 1.6) cmH2O and without IAH ((9.5 ± 2.1) cmH2O vs. (7.8 ± 1.9) cmH2O). Arterial pressure of O2/fraction of inspired oxygen (PaO2/FiO2) was much higher under PEEP titrated by Ptp when compared with PEEP titrated by ARDSnet protocol in ARDS patients with IAH ((27.2 ± 4.0) cmHg vs. (20.9 ± 5.0) cmHg. But no significant difference of PaO2/FiO2 between the two methods was found in ARDS patients without IAH. In ARDS patients with IAH, static compliance of lung and respiratory system were higher under PEEP titrated by Ptp than by ARDSnet protocol. In ARDS patients with IAH, central venous pressure (CVP) was higher during PEEP titrated by Ptp than by ARDSnet protocol.</p><p><b>CONCLUSION</b>Positive end expiratory pressure titrated by transpulmonary pressure was higher than PEEP titrated by ARDSnet protocol and improved oxygenation and respiratory mechanics in ARDS patients with IAH.</p>
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Intra-Abdominal Hypertension , Therapeutics , Positive-Pressure Respiration , Methods , Respiratory Distress Syndrome , Therapeutics , Respiratory Mechanics , PhysiologyABSTRACT
<p><b>OBJECTIVE</b>To detect the changes of central venous-to-arterial carbon dioxide difference (P(cv-a)CO(2)) during early goal-directed therapy (EGDT) in patients with septic shock and evaluate its' value in predicting adequate resuscitation and prognosis.</p><p><b>METHODS</b>From April 2009 to October 2010, 26 septic shock patients were enrolled in the study. EGDT was performed in all the patients immediately after enrollment. According to the whether they achieved early goal with in the 6 hour or not, patients were separated to EGDT achievement and un-achievement groups. At the onset and after the 6 hours EGDT, mean arterial pressure (MAP), cardiac index (CI), central venous oxygen saturation (ScvO(2)), oxygen delivery (DO(2)), oxygen consumption (VO(2)), oxygen extraction ratio (O(2) ext), lactate, P(cv-a)CO(2) were recorded. The Acute Physiology and Chronic Health Evaluation II (APACHE II) score and 28 day mortality were compared between 2 groups.</p><p><b>RESULTS</b>There were no significant difference of age and sex between the 15 patients who achieved early goals and 11 patients who did not. EGDT un-achievement patients had higher APACHE II score (21 ± 5) and 28 day mortality (9/11) when compared with EGDT achievement patients (t = 2.985, χ(2) = 4.547, P < 0.05). In EGDT un-achievement group, MAP, CI, DO(2), VO(2), O(2)ext, ScvO(2), Lac, P(cv-a)CO(2) were comparable between the onset and 6 hours after EGDT. However, in EGDT achievement group, MAP ((90 ± 9) mmHg (1 mmHg = 0.133 kPa)), CI ((4.0 ± 1.8) L×min(-1)×m(-2)), DO(2) ((596 ± 274) ml×min(-1)×m(-2)), ScvO(2) (76.9% ± 4.1%) increased, and P(cv-a)CO(2) ((4.2 ± 2.7) mmHg) decreased significantly after 6 hours of EGDT (t values were -3.393, -2.985, -2.103 and -3.195 respectively, all P < 0.05). The changes of P(cv-a)CO(2) between the onset and 6 hours after EGDT, demonstrated high value for predictability of outcome, according to the area under the ROC curve (AUC) was 0.839 (P = 0.004). As a predictor for death, increasing of P(cv-a)CO(2) after 6 hours of EGDT has a sensibility of 100% and specificity of 60%.</p><p><b>CONCLUSIONS</b>Increasing of P(cv-a)CO(2) after EGDT purports inadequate tissue perfusion in patients with septic shock. Changes of P(cv-a)CO(2) during EGDT demonstrated a useful tool to evaluate adequate resuscitation and prognosis.</p>
Subject(s)
Aged , Aged, 80 and over , Female , Humans , Male , Middle Aged , Blood Gas Analysis , Carbon Dioxide , Blood , Prognosis , Resuscitation , Shock, Septic , Blood , TherapeuticsABSTRACT
BACKGROUND: Pulmonary stretch reflex plays an important role in regulation of respiratory movement. This study aimed to evaluate the effect of pulmonary stretch reflex on lung injury in rabbits with acute respiratory distress syndrome (ARDS). METHODS: ARDS rabbits were given intratracheal infusion of hydrochloric acid and ventilated with neurally adjusted ventilatory assistance (NAVA) with a tidal volume (VT) of 6 mL/kg and the electrical activity of diaphragm (EAdi)-determined positive end expiratory pressure. After isolation of the bilateral vagusnerve trunk, the rabbits were randomized into two groups: sham operation (SHAM) group (n=5) and bilateral vagotomy (VAG) group (n=5). Gas exchange and respiratory mechanics were detected at baseline, after lung injury and 1, 2, and 3 hours after ventilation respectively. Pulmonary permeability index, pathological changes and inflammatory response were also measured. RESULTS: Compared with the SHAM group, PaO2/FiO2 in the VAG group decreased significantly 2 and 3 hours after ventilation (P<0.05). There was no significant difference in PaCO2 between the SHAM and VAG groups (P>0.05), and the VAG group had a high VT, peak pressure (Ppeak), and mean pressure (Pm) compared with the SHAM group 1, 2, 3 hours after ventilation (P<0.05). Compared to the SHAM group, dead space fraction (VD/VT) and respiratory system elastance (Ers) in the VAG group increased (P<0.05) and static pulmonary compliance (Cst) decreased markedly (P<0.05) after ventilation for 3 hours. Lung wet/dry weight ratio (W/D) (8.4±1.2 vs. 6.6±1.0), lung injury score (6.3±1.8 vs. 3.8±1.3), tumor necrosis factor-α (TNF-α) (779±372 pg/mL vs. 355±130 pg/mL) and interleukin-8 (IL-8) (169±21 pg/mL vs. 118±17 pg/mL) increased significantly in the VAG group compared with the SHAM group (P<0.05). CONCLUSION: Lung injury is aggravated after bilateral vagotomy, demonstrating that pulmonary stretch reflex may have protective effect on the lung.
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the correlation between the lactate in artery blood and lactate clearance rate and prognosis in patients with septic shock in intensive care unit (ICU).</p><p><b>METHODS</b>Prospectively studied 221 consecutive patients with septic shock from December 2005 to December 2007, the diagnosis of septic shock was made based on the criteria of 2001 ACCP/SCCM. For inclusion in the study, we required admission of the patients within 24 h of septic shock diagnosed. The criteria for exclusion from the study were an age of less than 18 years, pregnancy, serious inadequacy of liver and renal, needing blood purification, or acidosis result of biguanides drugs, or do-not-resuscitate. The eligible patients assigned to early goal-directed therapy. The 6-, 24- and 72-hour lactate clearance rate were calculated, the relationship between the level of lactate, lactate clearance rate, the APACHE II score, the number of failed organ and the 28-day mortality were evaluated.</p><p><b>RESULTS</b>One hundred and five patients with septic shock were admitted, 74 male and 31 female, the mean age was 70 +/- 12 years. The 28-day mortality was 54.3%. The average APACHE II score at baseline was 20 +/- 8, the number of failed organs was 3.0 +/- 1.1 and the average concentration of lactate in artery blood at baseline was (3.8 +/- 3.6) mmol/L. Significant differences of the lactate at 0-, 6-, 24- and 72-hour were found between death group and survival group. There were 69 patients whose lactate in artery blood at baseline was > 2 mmol/L, 24 survived. The lactate clearance rate of 6- and 24-hour in survival group were significantly higher than death group (P < 0.01, P < 0.05, respectively), but the lactate clearance rate of 72-hour was not (P > 0.05). By using a multivariate logistic regression analysis, it showed that the lactate clearance rate of 6-hour was the independent predictive factor of survival. The area under the receiver operating characteristic curve (ROC) was 0.564, 0.649, 0.754, 0.784, respectively according to the level of the lactate at 0-, 6-, 24-hour and the 6-hour lactate clearance rate. The cutoff of 6-hour lactate clearance rate was >or= 30.0%, resulting in a sensitivity of 60.0% and a specificity of 77.3%.</p><p><b>CONCLUSIONS</b>Dynamic observation of lactate level is very important for the survival in the patients with septic shock. Patients with elevated lactate and not decreased rapidly have a worse outcome. The 6-hour lactate clearance rate might be the indicator for predicting the prognosis of patients with septic shock.</p>