Integrated cardiopulmonary sonography: a useful tool for assessment of acute pulmonary edema in the intensive care unit.

OBJECTIVES: Bedside sonography has become a popular method of assessment of critically ill patients with shock and dyspnea. This study evaluated the usefulness of integrated cardiopulmonary sonography for assessment of acute pulmonary edema. METHODS: A total of 128 intensive care unit (ICU) patients with acute pulmonary edema were randomly divided into 2 groups: a sonography group, which received standard treatment as well as cardiopulmonary sonography, and a control group, which received standard treatment only. All patients were treated according to the same therapeutic strategies and underwent chest radiography and central venous catheter placement. Serum myocardial injury marker levels and central venous/arterial blood gas parameters were measured 0, 24, and 72 hours after enrollment. The cumulative fluid infusion volume at 6, 12, 24, and 72 hours, the time to diagnosis of the pulmonary edema etiology by the attending physician, the lengths of ICU and hospital stays, and ICU mortality were recorded. RESULTS: The sonography group had a shorter time to diagnosis and received a smaller fluid infusion volume than the control group. There were no significant differences in ICU mortality and lengths of ICU and hospital stays between the sonography and control groups. In patients with cardiogenic pulmonary edema, the sonography group had a significantly shorter ICU stay and a faster return to normal myocardial injury marker levels and perfusion parameters than the control group (P < .05). CONCLUSIONS: Integrated cardiopulmonary sonography resulted in faster and better-informed clinical decision making, shortened the time to diagnosis of the pulmonary edema etiology, and decreased fluid use. However, the impact of this examination on prognoses requires further study. We propose that integrated cardiopulmonary sonography may be a useful bedside tool for treatment of ICU patients with acute pulmonary edema.

[Value of peripheral perfusion index in the assessment of reactive hyperemia in septic patients].

OBJECTIVE: To explore the changes of peripheral perfusion index (PI) during forearm vascular occlusion test (VOT) and examine its evaluative value of reactive hyperemia in septic patients. METHODS: Twenty-one patients with septic shock, 21 postoperative ones without infection and 18 health volunteers were prospectively recruited to undergo vascular occlusion test. An arrest of forearm blood flow was applied for 3 min with a sphygmomanometer inflated to a pressure approximately 30 mm Hg greater than systolic pressure around forearm. PI was measured and recorded continuously by conventional pulse oximetry during VOT. RESULTS: (1)In all subjects, the PI values decreased to zero during ischemic period. There were no changes in heart rate or blood pressure between baseline and reperfusion. The maximum PI (PI-max) after a release of pneumatic cuff was significantly higher than baseline PI; (2)The change rates of PI-max and PI were significantly lower and the time to PI-max was longer in septic group after reperfusion; (3) A negative relationship existed between PI change rate and sequential organ failure assessment (SOFA) score in septic group. CONCLUSIONS: PI may be used to assess vascular reactive hyperemia in critically ill patients. And the capacity of peripheral vascular reactive hyperemia decreases in septic patients.

[Clinical role of evaluating vascular paralysis in septic shock patients].

OBJECTIVE: To explore the effects of vascular paralysis upon prognosis and tissue perfusion in septic shock patients. METHODS: A total of 73 septic shock patients consecutively admitted into our department from January 2010 to July 2011 were retrospectively studied. Their hemodynamic data, arterial lactate concentration and APACHEII (acute physiology & chronic health evaluation II) score at the beginning of cardiac output monitoring (0h), as well as the outcome of Day 28 post-diagnosis were recorded. Stroke volume index (SVI) and cardiac index (CI) were obtained through transpulmonary thermodilution technique by pulse induced continuous cardiac output (PiCCO) system. RESULTS: (1) APACHEII score at 0h was higher in non-survivors than those in survivors ((14.6 ± 5.6) vs (20.4 ± 4.8), P < 0.01). Stroke systemic vascular resistance index (SSVRI), pulse pressure/stroke volume index (PP/SVI), effective arterial elastance index (EaI), 24h lactate clearance rate (24rLac) , 72h lactate clearance rate (72rLac) and 7d lactate clearance rate (7rLac) in non-survivors were all lower than those in survivors (P < 0.05); (2) SVRI, SSVRI, PP/SVI and EaI were all correlated significantly with 24rLac, 72rLac and 7rLac [ (212.7 ± 52.6) vs (185.4 ± 50.5) , PP/SVI: (2.8 ± 0.7) vs (2.5 ± 0.6), EaI: (5.0 ± 1.2) vs (4.3 ± 1.1), 24/72/7 rLac: (18.4 ± 46.4) vs (21.5 ± 49.7), (19.9 ± 49.6) vs (-21.5 ± 46.3), (35.5 ± 45.8) vs (-59.5 ± 64.5), P < 0.00]. CONCLUSION: Vascular paralysis is correlated with prognosis and tissue perfusion in septic shock patients. And SSVRI, PP/SVI and EaI are more significant.

[Predication of volume responsiveness by brachial artery velocity change during passive leg raising].

OBJECTIVE: To evaluate whether or not brachial artery peak velocity (Vpeak-BA) induced by passive leg raising (PLR) may predict volume responsiveness. METHODS: We prospectively studied 29 patients enrolled into our intensive care unit (ICU) with spontaneous breathing during mechanical ventilation. Through echocardiography we compared the changes of brachial artery peak velocity induced by passive leg raising (ΔVBA-PLR) and the changes of left ventricle outflow tract velocity-time integral after volume expansion (ΔVTI-VE). Also the sensitivity and specificity of ΔVpeak-BA were determined in predicting volume responsiveness. RESULTS: Among them, 15 responded to volume expansion and the rest 14 did not. ΔVBA-PLR and ΔVTI-VE were mutually correlated (R(2) = 0.378, P = 0.011). The sensitivity and specificity of ΔVpeak-BA ≥ 16% to predict volume responsiveness were 73% and 87% respectively. CONCLUSION: Brachial artery peak velocity induced by passive leg raising is a reliable indicator of predicting volume responsiveness in patients with spontaneous breathing.

[Variations of left ventricular-arterial coupling in septic shock].

OBJECTIVE: To explore the variations of left ventricular-arterial coupling and elucidate its mechanisms in septic shock. METHODS: Septic shock rabbits were established by an intravenous injection of endotoxin. A total of 12 rabbits were divided randomly into sham operation group (S, n = 6) and endotoxin injection group (E, n = 6). Ultrasonic echocardiography and hemodynamic monitoring were conducted at 0h (30-min post-operation), 2h (1-hour after endotoxin or saline injection) and 4h (3-hour after endotoxin or saline injection) and the relative hemodynamic indices were recorded. RESULTS: (1) In E group, end-systolic elastance (Ees) at 2h was lower than that at 0h (75.72 ± 5.16 vs 90.77 ± 7.17 mm Hg/ml) and Ees at 4h was lower than that at 2h (58.45 ± 3.63 vs 75.72 ± 5.16 mm Hg/ml, P < 0.05); (2) In E group, left ventricular diastolic volume (LVDV) at 2h and 4h were both lower than that at 0h (3.26 ± 0.21 vs 3.58 ± 0.25 ml, 3.27 ± 0.19 vs 3.58 ± 0.25 ml). And left ventricular end diastolic compliance (Ced) at 4h were lower than that at 0h and 2h (0.61 ± 0.05 vs 0.74 ± 0.07 ml/mm Hg, 0.61 ± 0.05 vs 0.75 ± 0.08 ml/mm Hg, P < 0.05); (3) In E group, Ea at 2h and 4h was lower than that at 0h (41.35 ± 2.87 vs 50.46 ± 3.22 mm Hg/ml, 40.13 ± 2.68 vs 50.46 ± 3.22 mm Hg/ml, P < 0.05); (4) In E group, Ea/Ees at 4h was higher than that at 0h and 4h (0.70 ± 0.07 vs 0.57 ± 0.06, 0.70 ± 0.07 vs 0.56 ± 0.05, P < 0.05). And Ea/Ees at 2h had no significant difference with that at 0h (0.56 ± 0.05 vs 0.57 ± 0.06, P < 0.05). CONCLUSION: During compensatory stage of septic shock, left ventricular-arterial coupling shows no significant variation. However, during decompensatory stage of septic shock, there is significant left ventricular-arterial decoupling. The main reason for decoupling lies in that the decrease of left myocardial contractility is more significant than that of left ventricular afterload. And ventricular diastolic dysfunction may also participate.

[The value of bedside lung ultrasound in emergency-plus protocol for the assessment of lung consolidation and atelectasis in critical patients].

OBJECTIVE: To investigate the effect of the bedside lung ultrasound in emergency(BLUE)-plus lung ultrasound protocol on lung consolidation and atelectasis of critical patients. METHODS: All patients who need to receive mechanical ventilation for more than 48 hours in ICU from June 2010 to December 2011 in Peking Union Medical College Hospital were included in the study. BLUE-plus and BLUE lung ultrasound, bedside X-ray, lung CT examination were performed on all patients at the same time. The condition of lung consolidation and atelectasis discovered by BLUE-plus lung ultrasound protocol was recorded and compared with bedside X-ray or lung CT. The difference in assessment of lung consolidation and atelectasis between BLUE-plus lung ultrasound protocol and BLUE protocol was compared. RESULTS: A total of 78 patients were finally enrolled in the study. The lung CT found 70 cases (89.74%) had different degrees of lung consolidation and atelectasis. The sensitivity, specificity and diagnostic accuracy of lung consolidation and atelectasis by the bedside chest X-ray were 31.29%, 75.00% and 38.46%, respectively. BLUE-plus lung ultrasound protocol found 68 cases with lung consolidation and atelectasis, and its sensitivity, specificity, and diagnostic accuracy were 95.71%, 87.50% and 94.87%, respectively, which were significantly higher than those of lung CT. BLUE protocol found 48 cases of lung consolidation and atelectasis, and its sensitivity, specificity, and diagnostic accuracy were 65.71%, 75.00% and 66.67%, respectively. The position of lung consolidation and atelectasis which hadn't been found by BLUE protocol was mainly proved to be located in the basement of lung by lung CT. CONCLUSIONS: The incidence of lung consolidation and atelectasis in critical patients who received mechanical ventilation is high. The BLUE-plus lung ultrasound protocol has a relatively higher sensitivity, specificity and diagnostic accuracy for consolidation and atelectasis, which can find majority of consolidation and atelectasis. As BLUE-plus lung ultrasound is a bedside noninvasive method allowing immediate assessment of most lung consolidation and atelectasis, it will be likely the alternative of the CT and play a key role in assessment of lung consolidation and atelectasis.

[Combination of central venous-to-arterial PCO2 difference with central venous oxygen saturation to guide the shock resuscitation].

OBJECTIVE: Central venous oxygen saturation (ScvO2) is a useful therapeutic target in septic shock and high-risk postoperative patients. We tested the hypothesis that central venous-to-arterial carbon dioxide difference (ΔPCO(2)) combine with ScvO2 to guide shock resuscitation is better than ScvO2 only. METHODS: A retrospective study was conducted for 93 septic shock and high-risk postoperative patients. They underwent resuscitation through early goal-directed therapy. We calculate whether there were correlations between the ΔPCO(2) and tissue perfusion index or blood flow index, including the beginning of resuscitation (T0) and after 6 hour resuscitation (T6). They were divided into 4 groups according to ΔPCO(2) and ScvO2. Then the clearance of lactate was compared between the groups. RESULTS: No correlation existed between ΔPCO(2) and tissue perfusion index. But there was some correlation between ΔPCO(2) and the indices of blood flow such as CO, ScvO2 and clearance of lactate. At T0, the correlation (r) between ΔPCO(2) and cardiac index was -0.858 (P = 0.029) and the correlation between ΔPCO(2) and ScvO2 -0.403 (P = 0.000). At T6, the correlation (r) between ΔPCO(2) and ScvO2 was -0.363 (P = 0.000) and the correlation between ΔPCO(2) and clearance of lactate -0.314 (P = 0.002). After continuous 6-hour resuscitation, there was significant difference in clearance of lactate between the groups. The clearance of lactate was the highest in the group of patients achieving the goals of both ScvO2 > 70% and ΔPCO(2) < 6 mm Hg. We further analysis the ΔPCO(2) < 6 mm Hg and ScvO2 > 70% subgroup and found that the 6 h lactate clearance rate were statistically significant difference. CONCLUSION: The combination of ΔPCO(2) and ScvO2 may guide the shock resuscitation. It helps identify the inadequately resuscitated when the ScvO2 goal is reached.

[Left ventricular-arterial coupling in the resuscitation of refractory septic shock].

OBJECTIVE: To explore the role of left ventricular-arterial coupling in the resuscitation of refractory septic shock. METHODS: A total of 58 patients with refractory septic shock admitted from January 2010 to July 2011 were retrospectively studied. Hemodynamic data, arterial lactate concentration and APACHEII (acute physiology & chronic health evaluation II) score at the beginning of and 24 hours after cardiac output monitoring, as well as the outcome of Day 28 post-diagnosis were recorded. Stroke volume index (SVI), cardiac index (CI) and global end diastolic volume index (GEDVI) were obtained through transpulmonary thermodilution technique by a pulse induced continuous cardiac output (PiCCO) system. Left ventricular end systolic volume index (LVESVI) was approximated to (GEDVI/4-SVI) while effective arterial elastance index/ventricular end systolic elastance index (EaI/EesI) was approximated to LVESVI/SVI. RESULTS: (1) APACHEII score at the 24th hour, 24 hs lactate clearance rate and 24 hs Ea/Ees variation (ΔEa/Ees) were higher in non-survivors than those in survivors; (2) binary Logistic regression analysis showed that ΔEa/Ees and APACHEII score at the 24th hour were the independent risk factors of mortality for refractory septic shock. And the OR value of ΔEa/Ees was higher than that of APACHEII score (2.04 vs 1.63). Their areas of ROC curve were 0.705 (95%CI 0.569 - 0.841, P = 0.007) and 0.939 (95%CI 0.878 - 1.000, P = 0.000) respectively; (3) all hemodynamic parameters at the beginning had no difference between ΔEa/Ees > 0 and ΔEa/Ees ≤ 0 groups. CI, SVI, EGDT (early goal-directed therapy) compliance rate at the 24th hour in the ΔEa/Ees > 0 group were lower than those in the ΔEa/Ees ≤ 0 group. The effective arterial elastance index (EaI) at the 24th hour and the mortality rate of Day 28 in the ΔEa/Ees > 0 group were higher than those in the ΔEa/Ees ≤ 0 group; (4) during the 24 hs treatment, ΔEa/Ees was correlated negatively with the variations of CI, SVI, EesI and lactate clearance rate and positively with the variations of heart rate, GEDVI, systolic vascular resistance index and EaI. CONCLUSION: ΔEa/Ees may be used as an excellent marker of predicting the outcome of refractory septic shock. Lowing Ea/Ees in resuscitation has beneficial effects on EGDT compliance, lactate clearance and outcome.

[Impact of extended focus assessed transthoracic echocardiography protocol in septic shock patients].

OBJECTIVE: To investigate the impact of extended focus assessed transthoracic echocardiography (eFATE) in septic shock patients. METHODS: A total of 83 septic shock patients were recruited. And they were divided into the eFATE and routine groups. In the routine group, the patients were assessed by routine methods. And in the eFATE group, the following parameters of central venous pressure (CVP), mean arterial pressure (MAP), cardiac index (CI), stroke volume index (SVI) and ScvO(2) (central venous oxygen saturation) were measured routinely. The PiCCO (pulse indicator continuous cardiac output) method was employed when needed. All parameters and the others [acute physiology and chronic health evaluation II (APACHEII) & lactate] were recorded every 6 h. At 6, 24, 72 h and 1 w, the fluid intake volumes were recorded. All values were analyzed by statistic methods. And the mortality rates of intensive care unit and Day 28 were recorded. RESULTS: In the eFATE group, the 24 h targeting rate was markedly higher than the routine group. Yet there was no effect on the 6 h targeting rate. In the eFATE group, the fluid intake volumes at 6, 24 h and 1 w were markedly lowered than those of the control group. And the myocardial inhibition occurred earlier versus the control group. There was no difference in mortality rate between two groups. CONCLUSION: eFATE plays an important role in the correct assessment of septic shock patients. But its prognostic impact remains to be further defined.

[Correlation of transcutaneous oxygen challenge test and central venous oxygen saturation in septic shock patients].

OBJECTIVE: To investigate the correlation of transcutaneous oxygen challenge test (OCT) [the degree of PtcO2 response to increased fractional inspired oxygen concentration (FiO2) of 1.0 is identified as transcutaneous OCT] and central venous oxygen saturation (ScvO2) in septic shock patients after resuscitation. METHODS: A total of 49 septic shock patients were prospectively studied. They underwent PtcO2 monitoring and OCT (a temporary increase of FiO2 for 10 min). Baseline central venous blood gases, baseline arterial blood gases and post-OCT arterial blood gases were examined. The parameters of PtcO2 index (baseline PtcO2/PaO2), tissue oxygen index (baseline PtcO2/FiO2), 10 min OCT value [(PtcO2 after 10 min on FiO2 of 1.0) minus (baseline PtcO2)], oxygen challenge index [(10 min OCT value)/(PaO2 on FiO2 1.0 minus baseline PaO2)] were calculated during OCT. The patients were divided into 2 groups according to ScvO2 values: normal ScvO2 group (ScvO2 ≥ 70%) versus low ScvO2 group (ScvO2 < 70%). The parametric differences of transcutaneous OCT were compared between two groups. RESULTS: (1) There was a significant correlation between baseline PtcO2 (r = 0.382, P = 0.007), tissue oxygen index (r = 0.355, P = 0.012), 10 min OCT value (r = 0.427, P = 0.002), oxygen challenge index (r = 0.5, P < 0.001) and ScvO2, but not with arterial blood lactate concentration; (2) there were 27 patients in the low ScvO2 group and 22 patients in the normal ScvO2 group. ScvO2 was significantly lower in the low ScvO2 group than in the normal ScvO2 group (61 ± 8 vs 77 ± 6, P < 0.05). No differences in age, severity score, vital signs, arterial blood lactate concentration, vasoactive drugs, PtcO2, PtcO2 index and tissue oxygen index were observed between these groups. Compared with those in the normal ScvO2 group, the patients in the low ScvO2 group had a lower 10 min OCT value and oxygen challenge index (P < 0.05); (3) the area under the receiver operating characteristic curve (ROC) for detecting the lower ScvO2 values was 0.621, 0.560, 0.589, 0.721 and 0.763 respectively according to baseline PtcO2, PtcO2 index, tissue oxygen index, 10 min OCT value and oxygen challenge index. The cutoff of 10 min OCT value was ≤ 57 mm Hg (1 mm Hg = 0.133 kPa) for detecting ScvO2 values under 70%, resulting in a sensitivity of 51.9% and a specificity of 95.5%. CONCLUSION: OCT may improve the diagnostic accuracy of PtcO2 in assessing the low ScvO2 values in septic shock patients after resuscitation.

[Effects of central venous pressure on acute kidney injury in septic shock].

OBJECTIVE: To investigate the effects of central venous pressure on acute kidney injury (AKI) in septic shock. METHODS: A total of 86 septic shock patients with PiCCO (pulse indicator continuous cardiac output) monitoring admitted at our department from January 2009 to January 2011 were retrospectively studied. They were divided into 2 groups based on central venous pressure (CVP) at 24 hs after PiCCO monitoring. There were 41 cases in low CVP group (CVP ≤ 10 mm Hg and 45 cases in high CVP group (CVP > 10 mm Hg). Their hemodynamic data, lactate concentration, ScvO2 (central venous oxygen saturation), APACHEII (acute physiology & chronic health evaluation II) score and serum creatinine were obtained at the beginning and 24 hours after PiCCO monitoring. The incidence and mortality of AKI, the outcome of these patients in ICU and at Day 28 post-diagnosis were recorded. RESULTS: (1) The incidences of AKI were 51.2% (21/41) and 75.6% (34/45) in low and high CVP groups respectively; (2) Nine cases (22.0%) died in ICU in low CVP group and 20 cases (44.4%) in high CVP group. And 12 cases (29.3%) died within 28 days in low CVP group while 21 cases (46.7%) in high CVP group. CONCLUSION: A high CVP may increase the incidence and morbidity of AKI in septic shock. And an excessively high CVP should be prevented.

[Correlation between pressure and volume parameters of septic shock patients with cardiac depression].

OBJECTIVE: To investigate the characteristics and influence of cardiac depression on patients with septic shock. METHODS: Seventy seven septic shock patients treated from January 2005 to June 2009 were retrospectively studied, they were divided into two groups based on cardiac index (CI) after early resuscitation, high CI group: CI >/= 3 L/(min.m(2)), low CI group: CI < 3 L/(min.m(2)). Rate of goal achievement, prognosis and whether the global end diastolic volume index (GEDI) increases with central venous pressure (CVP) growth of the two groups were compared. RESULTS: There were 38 patients in the low CI group, and 39 patients in the high CI group. Compared with patients in the high CI group, patients in the low CI group had older age and higher APACHE II score (P < 0.05). Compared with patients in the high CI group, patients in the low CI group had higher mortality rate and lower rate of goal achievement (P < 0.05). In low CI group, 16 patients' GEDI didn't increase with CVP growth, and in high CI group only 6 patients' GEDI didn't increase with CVP growth (P < 0.05); In low CI group, patients whose GEDI didn't increase with CVP growth had higher arterial lactate, lower ScvO(2), lower rate of goal achievement and worse prognosis than patients whose GEDI increased with CVP growth(P < 0.05). CONCLUSIONS: For septic shock patients, correlation between CVP and GEDI can reflect cardiac function. Especially for patients with low CI, GEDI doesn't increase with CVP growth is a signal of cardiac depression and can be an early indicator of worse prognosis. Older septic shock patients and those with higher APACHE II score tend to have the complication of cardiac depression.

[The clinical significance of Aspergillus isolation from airway samples in critically ill patients].

OBJECTIVE: To analyze the risk factors and clinical significance of Aspergillus isolation from airway samples of critically ill patients. METHODS: The study was conducted in an ICU between January 2007 and December 2007. The data of patients receiving mechanical ventilation with suspected invasive pulmonary fungal infection were analyzed. Tracheal aspirates were collected and cultured 3 times weekly. The cases were classified into groups of Aspergillus spp, Candida spp, and non-fungus spp according to the microbiological results. Isolation of Aspergillus spp. was subgrouped to proved-IPA (invasive pulmonary aspergillosis), probable-IPA or colonization. The risk factors for airway isolation of Aspergillus and infection were assessed. Statistical analysis was performed using the Statistical Package for the Social Sciences (SPSS) for Windows (version 12.0) and quantitative variables were expressed as mean +/- standard deviation. The Student' s t-test or the Mann-Whitney U-test was used for the comparison of categorical and normally distributed and non normally distributed variables, respectively. The chi2 test or the Fisher's exact test was used in the comparison of categorical variables. Logistic regression analysis was conducted to evaluate risk factors for the isolation of Aspergillus spp. RESULTS: The study population included 160 patients (82 men) with a mean age of (64.5 +/- 17.2) years. Aspergillus spp was isolated in 45, Candida spp in 63, and non-fungus spp in 52. The ICU mortality in the 3 groups was 48.9% (22/45 cases), 23.8% (15/63 cases), 7.7% (4/52 cases), respectively. The ICU mortality in patients with Aspergillus spp. isolation was higher than those with Candida spp and non-fungus spp. In 28 patients isolation of Aspergillus spp. was interpreted as invasive aspergillosis (2 patients were proven, 26 patients were probable). The predictive value of isolating Aspergillus from airway samples was 62% (28/45 cases). On multivariate analysis, the following factors were independently associated with Aspergillus spp. isolation: connective tissue diseases (OR 3.3, 95% CI 1.7 - 12.2, chi2 = 4.82, P<0.01), hepatic dysfunction (OR 8.1, 95% CI 1.7 - 15.2, chi2 = 19.2, P<0.01), corticosteroid use (OR 4.6, 95% CI 2.6 - 13.7, chi2 = 8.92, P<0.01) and continuous renal replacement therapy (CRRT) (OR 5.1, 95% CI 2.6 - 11.5, chi2 = 11.4, P<0.01). Higher APACHE II score (25 +/- 6, 14 +/- 8, t = 2.75, P<0.01), septic shock (57%, 27%, chi2 = 3.56, P<0.01), and prolonged use of broad-spectrum antibiotics (15.9 d, 9.2 d, t = 2.49, P<0.01) were significantly associated with Aspergillus infection as compared to colonization. CONCLUSION: Critically ill patients with Aspergillus from airway samples had a higher mortality. Connective tissue diseases, hepatic dysfunction, corticosteroid use and CRRT were significantly associated with Aspergillus spp. isolation in critically ill patients. In severely ill patients, the isolation of Aspergillus is highly indicative of infection rather than colonization.

Microcirculation dysfunction in endotoxic shock rabbits is associated with impaired S-nitrosohemoglobin-mediated nitric oxide release from red blood cells: a preliminary study.

BACKGROUND: Microcirculation dysfunction with blood flow heterogeneity is an important characteristic in sepsis shock. We hypothesized that impaired ability of red blood cells to release nitric oxide resulted in microcirculation dysfunction in sepsis shock. METHODS: 4,4'-Diisothiocyanatostilbene-2,2'-disulfonic acid disodium salt hydrate (DIDS), an inhibitor of band3 protein, was used to inhibit S-nitrosohemoglobin-mediated nitric oxide release. Rabbits were randomly divided into four groups: control (n = 6), lipopolysaccharide (LPS) (n = 6), LPS + DIDS (n = 6), and control + DIDS group (n = 6). Macrocirculation (cardiac output and mean arterial pressure) and microcirculation (microvascular flow index and flow heterogeneity index) parameters were recorded. At 2-h time point, arterial and venous S-nitrosohemoglobin concentrations were measured. RESULTS: The arterial-venous difference for S-nitrosohemoglobin in the LPS group was lower than the control group (27.3 ± 5.0 nmmol/L vs. 40.9 ± 6.2 nmmol/L, P < 0.05) but was higher than the LPS + DIDS group, with a statistically significant difference (27.3 ± 5.0 nmmol/L vs. 16.0 ± 4.2 nmmol/L, P < 0.05). Microvascular flow index for the LPS group at 2 h was lower than the control group (1.13 ± 0.16 vs. 2.82 ± 0.08, P < 0.001) and higher than the LPS + DIDS group (1.13 ± 0.16 vs. 0.84 ± 0.14, P < 0.05). Flow heterogeneity index for the LPS group at 2 h was higher than the control group (1.03 ± 0.27 vs. 0.16 ± 0.06, P < 0.001) and lower than the LPS + DIDS group (1.03 ± 0.27 vs. 1.78 ± 0.46, P < 0.001). CONCLUSIONS: In endotoxic shock rabbits, the ability of S-nitrosohemoglobin-mediated nitric oxide release from RBC was impaired, and there was an association between the ability and microcirculation dysfunction especially increased blood flow heterogeneity.

[The hemodynamic investigation of refractory septic shock-related cardiac dysfunction].

OBJECTIVE: To research and analyze the hemodynamic status of refractory septic shock associated cardiac dysfunction. METHODS: 70 refractory septic shock patients were studied. In the duration of pulmonary artery catheter (PAC)-directed hemodynamic optimization, the patients were divided into a cardiac dysfunction group and a control group. Hemodynamic parameters, arterial blood lactate concentration and APACHE II scores were obtained instantly after the placement of a PAC, then lactate clearance in 24 hours was surveyed and calculated. Subsequently the two groups of patients were regrouped by nonsurvivor and survivors respectively. All the obtained values were analyzed with statistic methods. RESULTS: 37% of the refractory septic shock patients was complicated with cardiac dysfunction. The age of the patients complicated with cardiac dysfunction was significantly higher than that of the patients of the control group. Central venous pressure (CVP), pulmonary artery obstruction pressure (PAOP), pulmonary artery pressure (PAP), systemic vascular resistance index (SVRI), pulmonary vascular resistance index (PVRI) and oxygen extraction ratio (O2ext) in the cardiac dysfunction group were significantly different from those in the control group. Cardiac output (CO), cardiac index (CI), oxygen delivery index (DO2I) and mixed venous oxygen saturation (SvO2) were significantly lower than those of the patients in the control group. SvO2 had a strong correlation with CI. If the patients were regrouped by nonsurvivors and survivors, in the patients complicated with cardiac dysfunction APACHE II scores were significantly higher in the nonsurvivors than survivors; the lactate clearance in 24 hours (median--25%) of the nonsurvivors was significantly lower than that of nonresponders (median 22%), P < 0.05. Conclusion (1) In refractory septic shock patients, cardiac dysfunction maybe the main reason leading to bad outcome. (2) Higher CVP and PAOP and lower SvO2 indicate the onset of cardiac dysfunction. (3) The patients with significantly high initial arterial blood lactate level and the low lactate clearance in 24 hours had bad outcome.

[The role of central venous pressure to evaluate volume responsiveness in septic shock patients].

OBJECTIVE: To investigate the clinical role of central venous pressure (CVP) to evaluate fluid responsiveness in septic shock patients. METHODS: 66 septic shock patients were studied, every patient was administered a volume challenge, before and after it, CVP, intrathoracic blood volume index (ITBVI), global end-diastolic volume index (GEDVI), cardiac index (CI), stroke volume index (SVI) were measured by PiCCO method. All the obtained values were analyzed by statistics method. RESULTS: Initial CVP in responders is significantly different from that in nonresponders; DeltaITBVI, DeltaGEDVI, DeltaCI, DeltaSVI, DeltaHR (Delta:changes) before and after volume challenge in responders were significantly different from those in nonresponders; the significance of DeltaITBVI, DeltaGEDVI to predict volume responsiveness was strong indicated by high values of areas under the receiver operating characteristic curves (0.674 and 0.700, respectively). If patients were regrouped by CVP 11 mm Hg, initial ITBVI and GEDVI in responders were not significantly different from that in nonresponders; DeltaITBVI, DeltaGEDVI, DeltaCI, DeltaSVI before and after volume challenge in responders were significantly different from those in nonresponders. CONCLUSION: In septic shock patients, CVP play a guidance role to predict and evaluate volume responsiveness and when CVP was > 11 mm Hg, a positive response will be less likely. Initial volumetric parameters (intrathoracic blood volume and global end-diastolic volume) play a questionable role in predicting and evaluating volume responsiveness, changes before and after volume challenge maybe helpful.

[Perioperative hemodynamics in pheochromocytoma secreting different types of catecholamine].

OBJECTIVE: To analyze the characteristics of perioperative hemodynamics in pheochromocytoma secreting different types of catecholamine, and to discuss how to improve the hemodynamics. METHODS: The clinical data of 202 patients with pheochromocytoma who had received operation were analyzed. Three classification systems were used to divided the patients: they were, firstly, divided into high and low epinephrine secreting groups (E(high) and E(low)) according to the 24 hours urine catecholamine quantitation; secondly, into high and low norepinephrine secreting groups (NE(high) and NE(low)) according to 24-h urine norepinephrine quantitation; and thirdly, into high and low dopamine secreting groups (DA(high) and DA(low)) according to the 24 hours urine dopamine quantitation. Relationship between the characteristics of perioperative hemodynamics and catecholamine secreting types were analyzed. RESULTS: The highest preoperative systolic blood pressure values of E(high) and NE(high) groups were (201 +/- 40) mm Hg and (205 +/- 38) mm Hg, both significantly higher than those of the E(low) and NE(low) groups [(183 +/- 43) mm Hg, P = 0.003 and (181 +/- 43) mm Hg, P = 0.000]. The range of systolic blood pressure fluctuation during the operation of the E(high) group was 108 +/- 39 mm Hg, significantly larger than that of the E(low) group (91 +/- 33 mm Hg, P = 0.001). The incidence rates of persisting postoperative hypotension of the NE(high) and DA(high) groups were 23.3% (20/86) and 32.7% (17/52) respectively, both higher than those of the NE(low) and DA(low) groups [2.6% (3/116) and 4.0% (6/150) respectively, P = 0.000 and P = 0.000]. CONCLUSION: Different characteristics of perioperative hemodynamics are present in pheochromocytoma secreting different types of catecholamines. Patients with highly epinephrine secreting pheochromocytoma are apt to have larger blood fluctuation during the operation. Patients with highly norepinephrine and dopamine secreting pheochromocytoma are apt to suffer from persisting postoperative hypotension.

[Early changes in function of hypothalamic-pituitary-target gland axis in patients with severe sepsis and septic shock].

OBJECTIVE: To investigate the early changes in function of hypothalamic-pituitary-target gland (HPTG) axis in patients with severe sepsis and septic shock, in order to clarify its relationship with severity and prognosis of the patients. METHODS: The serum contents of cortisol (F), triiodothyronine (T(3)), thyroxine (T(4)), thyrotropic-stimulating hormone (TSH), growth hormone (GH), follicle-stimulating hormone (FSH), luteotropic hormone (LH), prolactin (PRL) and plasma concentration of adrenocorticotrophic hormone (ACTH) in 10 severe sepsis and 12 septic shock patients on day 1, 3, 5 after diagnosis was made, and 12 patients with no infection or septic shock served as controls. The hypothalamic-pituitary adrenal gland axis (HPAA) function of the patients with severe sepsis and septic shock were evaluated with 1 microgram ACTH stimulation test given 1 day after the concentrations of the above hormones were determined. RESULTS: Compared with the control patients, ACTH, T(3), T(4), GH, FSH, LH and PRL levels were significantly changed in patients with severe sepsis and septic shock (P<0.05 or P<0.01). The numbers of patients with reaction to 1 microgram ACTH stimulation test were similar between patients with severe sepsis (6 cases non-reaction and 3 cases reaction) and patients with septic shock (9 cases non reaction and 2 cases reaction, P>0.05). According to the acute physiology and chronic health evaluation II (APACHE II) and sepsis-related organ failure assessment (SOFA) score, changes in ACTH, T(3), T(4), GH and PRL levels were closely related to the severity of illness (P<0.05 or P<0.01). Significant differences were found in ACTH, T(3), T(4) levels between survivors and non-survivors (P<0.05 or P<0.01). ACTH, T(4) levels and SOFA score were independent predictors of the 28-day hospital mortality (P<0.05 or P<0.01). CONCLUSION: The early changes in HPTG axis are closely related with the severity and hospital mortality in patients with severe sepsis and septic shock.