Skin mottling score assesses peripheral tissue hypoperfusion in critically ill patients following cardiac surgery.

BACKGROUND: Skin mottling is a common manifestation of peripheral tissue hypoperfusion, and its severity can be described using the skin mottling score (SMS). This study aims to evaluate the value of the SMS in detecting peripheral tissue hypoperfusion in critically ill patients following cardiac surgery. METHODS: Critically ill patients following cardiac surgery with risk factors for tissue hypoperfusion were enrolled (n = 373). Among these overall patients, we further defined a hypotension population (n = 178) and a shock population (n = 51). Hemodynamic and perfusion parameters were recorded. The primary outcome was peripheral hypoperfusion, defined as significant prolonged capillary refill time (CRT, > 3.0 s). The characteristics and hospital mortality of patients with and without skin mottling were compared. The area under receiver operating characteristic curves (AUROC) were used to assess the accuracy of SMS in detecting peripheral hypoperfusion. Besides, the relationships between SMS and conventional hemodynamic and perfusion parameters were investigated, and the factors most associated with the presence of skin mottling were identified. RESULTS: Of the 373-case overall population, 13 (3.5%) patients exhibited skin mottling, with SMS ranging from 1 to 5 (5, 1, 2, 2, and 3 cases, respectively). Patients with mottling had lower mean arterial pressure, higher vasopressor dose, less urine output (UO), higher CRT, lactate levels and hospital mortality (84.6% vs. 12.2%, p < 0.001). The occurrences of skin mottling were higher in hypotension population and shock population, reaching 5.6% and 15.7%, respectively. The AUROC for SMS to identify peripheral hypoperfusion was 0.64, 0.68, and 0.81 in the overall, hypotension, and shock populations, respectively. The optimal SMS threshold was 1, which corresponded to specificities of 98, 97 and 91 and sensitivities of 29, 38 and 67 in the three populations (overall, hypotension and shock). The correlation of UO, lactate, CRT and vasopressor dose with SMS was significant, among them, UO and CRT were identified as two major factors associated with the presence of skin mottling. CONCLUSION: In critically ill patients following cardiac surgery, SMS is a very specific yet less sensitive parameter for detecting peripheral tissue hypoperfusion.

Furosemide Responsiveness Predicts Acute Kidney Injury Progression After Cardiac Surgery.

BACKGROUND: As patients with acute kidney injury (AKI) progress to a higher stage, the risk for poor outcomes dramatically rises. Early identification of patients at high risk for AKI progression remains a major challenge. This study aimed to evaluate the value of furosemide responsiveness (FR) for predicting AKI progression in patients with initial mild and moderate AKI after cardiac surgery. METHODS: We performed 2 separate exploratory analyses. The Zhongshan cohort was a single-center, prospective, observational cohort, whereas the Beth Israel Deaconess Medical Center cohort was a single-center, retrospective cohort. We calculated 2 FR parameters for each patient, namely the FR index and modified FR index, defined as 2-hour urine output divided by furosemide dose (FR index, mL/mg/2 h) and by furosemide dose and body weight (modified FR index, mL/[mg·kg]/2 h), respectively. The primary outcome was AKI progression within 7 days. RESULTS: AKI progression occurred in 80 (16.0%) and 359 (11.3%) patients in the Zhongshan and Beth Israel Deaconess Medical Center cohorts, respectively. All FR parameters (considered continuously or in quartiles) were inversely associated with risk of AKI progression in both cohorts (all adjusted P < .01). The addition of FR parameters significantly improved prediction for AKI progression based on baseline clinical models involving C-index, net reclassification improvement, and integrated discrimination improvement index in both cohorts (all P < .01). CONCLUSIONS: FR parameters were inversely associated with risk of AKI progression in patients with mild and moderate AKI after cardiac surgery. The addition of FR parameters significantly improved prediction for AKI progression based on baseline clinical models.

Change in left ventricular velocity time integral during Trendelenburg maneuver predicts fluid responsiveness in cardiac surgical patients in the operating room.

BACKGROUND: Fluid responsiveness is an important topic for clinicians. We investigated whether changes in left ventricular outflow tract (LVOT) velocity time integral (VTI) during a Trendelenburg position (TP) maneuver can predict fluid responsiveness as a non-invasive marker in coronary artery bypass graft (CABG) surgery patients in the operating room. METHODS: This prospective, single-center observational study, performed in the operating room, enrolled 65 elective CABG patients. Hemodynamic data coupled with transesophageal echocardiography monitoring of the LVOT VTI and the peak velocity were collected at each step [baseline 1, TP, baseline 2 and fluid challenge (FC)]. Patients whose VTI increased ≥15% after FC (500 mL of Gelofusine infusion within 30 min) were considered responders. RESULTS: Twenty-eight (43.1%) patients were responders to fluid administration. VTI changes during the TP maneuver predicted fluid responsiveness with an area under the receiver operating characteristic curve (AUC) of 0.90 (95% CI, 0.79-0.96), with a sensitivity of 100%, and a specificity of 70% at a threshold of 10% (gray zone, 8-15%). The increase in VTI during the TP was correlated with the VTI changes induced by FC (r=0.61, P<0.0001). Changes in peak velocity and pulse pressure during the TP were poorly predictive of fluid responsiveness, with an AUC of 0.72 (95% CI: 0.60-0.82) and 0.66 (95% CI: 0.53-0.77), respectively. CONCLUSIONS: An increase in VTI induced by the TP could predict fluid responsiveness in CABG patients in the operating room. However, changes in peak velocity and pulse pressure stimulated by the TP could not reliably predict fluid responsiveness.

Inhaled nitric oxide reduces the intrapulmonary shunt to ameliorate severe hypoxemia after acute type A aortic dissection surgery.

BACKGROUND: To assess the relationship between the intrapulmonary shunt and PaO2/FiO2 in severe hypoxemic patients after acute type A aortic dissection (ATAAD) surgery and to evaluate the effect of inhaled nitric oxide (iNO) on intrapulmonary shunt. METHODS: Postoperative ATAAD patients with PaO2/FiO2 ≤ 150 mmHg were enrolled. Intrapulmonary shunt was calculated from oxygen content of different sites (artery [CaO2], mixed venous [CvO2], and alveolar capillary [CcO2]) using the Fick equation, where intrapulmonary shunt = (CcO2-CaO2)/(CcO2-CvO2). Related variables were measured at baseline (positive end expiratory pressure [PEEP] 5 cm H2O), 30 min after increasing PEEP (PEEP 10 cm H2O), 30 min after 5 ppm iNO therapy (PEEP 10 cm H2O + iNO), and 30 min after decreasing PEEP (PEEP 5 cm H2O + iNO). RESULTS: A total of 20 patients were enrolled between April 2019 and December 2019. Intrapulmonary shunt and PaO2/FiO2 were correlated in severe hypoxemic, postoperative ATAAD patients (adjusted R2 = 0.467, p < 0.001). A mixed model for repeated measures revealed that iNO, rather than increasing PEEP, significantly decreased the intrapulmonary shunt (by 15% at a PEEP of 5 cm H2O and 16% at a PEEP of 10 cm H2O, p < 0.001 each) and increased PaO2/FiO2 (by 63% at a PEEP of 5 cm H2O and 65% at a PEEP of 10 cm H2O, p < 0.001 each). After iNO therapy, the decrement of intrapulmonary shunt and the increment of PaO2/FiO2 were also correlated (adjusted R2 = 0.375, p < 0.001). CONCLUSIONS: This study showed that intrapulmonary shunt and PaO2/FiO2 were correlated in severe hypoxemic, postoperative ATAAD patients. Furthermore, iNO, rather than increasing PEEP, significantly decreased the intrapulmonary shunt to improve severe hypoxemic conditions.

Trendelenburg maneuver predicts fluid responsiveness in patients on veno-arterial extracorporeal membrane oxygenation.

BACKGROUND: Evaluation of fluid responsiveness during veno-arterial extracorporeal membrane oxygenation (VA-ECMO) support is crucial. The aim of this study was to investigate whether changes in left ventricular outflow tract velocity-time integral (ΔVTI), induced by a Trendelenburg maneuver, could predict fluid responsiveness during VA-ECMO. METHODS: This prospective study was conducted in patients with VA-ECMO support. The protocol included four sequential steps: (1) baseline-1, a supine position with a 15° upward bed angulation; (2) Trendelenburg maneuver, 15° downward bed angulation; (3) baseline-2, the same position as baseline-1, and (4) fluid challenge, administration of 500 mL gelatin over 15 min without postural change. Hemodynamic parameters were recorded at each step. Fluid responsiveness was defined as ΔVTI of 15% or more, after volume expansion. RESULTS: From June 2018 to December 2019, 22 patients with VA-ECMO were included, and a total of 39 measurements were performed. Of these, 22 measurements (56%) met fluid responsiveness. The R2 of the linear regression was 0.76, between ΔVTIs induced by Trendelenburg maneuver and the fluid challenge. The area under the receiver operating characteristic curve of ΔVTI induced by Trendelenburg maneuver to predict fluid responsiveness was 0.93 [95% confidence interval (CI) 0.81-0.98], with a sensitivity of 82% (95% CI 60-95%), and specificity of 88% (95% CI 64-99%), at a best threshold of 10% (95% CI 6-12%). CONCLUSIONS: Changes in VTI induced by the Trendelenburg maneuver could effectively predict fluid responsiveness in VA-ECMO patients. Trial registration ClinicalTrials.gov, NCT03553459 (the TEMPLE study). Registered on May 30, 2018.

Remifentanil versus dexmedetomidine for treatment of cardiac surgery patients with moderate to severe noninvasive ventilation intolerance (REDNIVIN): a prospective, cohort study.

BACKGROUND: The use of sedation to noninvasive ventilation (NIV) patients remains controversial, however, for intolerant patients who are uncooperative, administration of analgesics and sedatives may be beneficial before resorting to intubation. The aim of this study was to evaluate the efficacy of remifentanil (REM) versus dexmedetomidine (DEX) for treatment of cardiac surgery (CS) patients with moderate to severe NIV intolerance. METHODS: This prospective cohort study of CS patients with moderate to severe NIV intolerance was conducted between January 2018 and March 2019. Patients were treated with either REM or DEX, decided by the bedside intensivist. Depending on the treatment regimen, the patients were allocated to one of two groups: the REM group or DEX group. RESULTS: A total of 90 patients were enrolled in this study (52 in the REM group and 38 in the DEX group). The mitigation rate, defined as the percentage of patients who were relieved from the initial moderate to severe intolerant status, was greater in the REM group than DEX group at 15 min and 3 h (15 min: 83% vs. 61%, P=0.029; 3 h: 92% vs. 74%, P=0.016), although the mean mitigation rate (81% vs. 85%, P=0.800) was comparable between the two groups. NIV failure, defined as reintubation or death over the course of study, was comparable between the two groups (19.2% vs. 21.1%, respectively, P=0.831). There were no significant differences between the two groups in other clinical outcomes, including tracheostomy (15.4% vs. 15.8%, P=0.958), in-hospital mortality (11.5% vs. 10.5%, P=0.880), ICU length of stay (LOS) (7 vs. 7 days, P=0.802), and in-hospital LOS (17 vs. 19 days, P=0.589). CONCLUSIONS: REM was as effective as DEX in CS patients with moderate to severe NIV intolerance. Although the effect of REM was better than that of DEX over the first 3 h, the cumulative effect was similar between the two treatments.

Comparison of the proximal and distal approaches for axillary vein catheterization under ultrasound guidance (PANDA) in cardiac surgery patients susceptible to bleeding: a randomized controlled trial.

BACKGROUND: The present study aimed at comparing the success rate and safety of proximal versus distal approach for ultrasound (US)-guided axillary vein catheterization (AVC) in cardiac surgery patients susceptible to bleeding. METHODS: In this single-center randomized controlled trial, cardiac surgery patients susceptible to bleeding and requiring AVC were randomized to either the proximal or distal approach group for US-guided AVC. Patients susceptible to bleeding were defined as those who received oral antiplatelet drugs or anticoagulants for at least 3 days. Success rate, catheterization time, number of attempts, and mechanical complications within 24 h were recorded for each procedure. RESULTS: A total of 198 patients underwent randomization: 99 patients each to the proximal and distal groups. The proximal group had the higher first puncture success rate (75.8% vs. 51.5%, p < 0.001) and site success rate (93.9% vs. 83.8%, p = 0.04) than the distal group. However, the overall success rates between the two groups were similar (99.0% vs. 99.0%; p = 1.00). Moreover, the proximal group had fewer average number of attempts (p < 0.01), less access time (p < 0.001), and less successful cannulation time (p < 0.001). There was no significant difference in complications between the two groups, such as major bleeding, minor bleeding, arterial puncture, pneumothorax, nerve injuries, and catheter misplacements. CONCLUSIONS: For cardiac surgery patients susceptible to bleeding, both proximal and distal approaches for US-guided AVC can be considered as feasible and safe methods of central venous cannulation. In terms of the first puncture success rate and cannulation time, the proximal approach is superior to the distal approach. Trial registration Clinicaltrials.gov, NCT03395691. Registered January 10, 2018, https://clinicaltrials.gov/ct2/show/NCT03395691?cond=NCT03395691&draw=1&rank=1 .

Evaluation of radial artery pulse pressure effects on detection of stroke volume changes after volume loading maneuvers in cardiac surgical patients.

BACKGROUND: Fluid responsiveness is defined as an increase in cardiac output (CO) or stroke volume (SV) of >10-15% after fluid challenge (FC). However, CO or SV monitoring is often not available in clinical practice. The aim of this study was to evaluate whether changes in radial artery pulse pressure (rPP) induced by FC or passive leg raising (PLR) correlates with changes in SV in patients after cardiac surgery. METHODS: This prospective observational study included 102 patients undergoing cardiac surgery, in which rPP and SV were recorded before and immediately after a PLR test and FC with 250 mL of Gelofusine for 10 min. SV was measured using pulse contour analysis. Patients were divided into responders (≥15% increase in SV after FC) and non-responders. The hemodynamic variables between responders and non-responders were analyzed to assess the ability of rPP to track SV changes. RESULTS: A total of 52% patients were fluid responders in this study. An rPP increase induced by FC was significantly correlated with SV changes after a FC (ΔSV-FC, r=0.62, P<0.01). A fluid-induced increase in rPP (ΔrPP-FC) of >16% detected a fluid-induced increase in SV of >15%, with a sensitivity of 91% and a specificity of 73%. The area under the receiver operating characteristic curve (AUROC) for the fluid-induced changes in rPP identified fluid responsiveness was 0.881 (95% CI: 0.802-0.937). A grey zone of 16-34% included 30% of patients for ΔrPP-FC. The ΔrPP-PLR was weakly correlated with ΔSV-FC (r=0.30, P<0.01). An increase in rPP induced by PLR (ΔrPP-PLR) predicted fluid responsiveness with an AUROC of 0.734 (95% CI: 0.637-0.816). A grey zone of 10-23% included 52% of patients for ΔrPP-PLR. CONCLUSIONS: Changes in rPP might be used to detect changes in SV via FC in mechanically ventilated patients after cardiac surgery. In contrast, changes in rPP induced by PLR are unreliable predictors of fluid responsiveness.

Serum N-terminal Pro-B-type Natriuretic Peptide Predicts Mortality in Cardiac Surgery Patients Receiving Renal Replacement Therapy.

Background: N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a useful cardiac biomarker that is associated with acute kidney injury (AKI) and mortality after cardiac surgery. However, its prognostic value in cardiac surgical patients receiving renal replacement therapy (RRT) remains unclear. Objectives: Our study aimed to assess the prognostic value of NT-proBNP in patients with established AKI receiving RRT after cardiac surgery. Methods: A total of 163 cardiac surgical patients with AKI requiring RRT were enrolled in this study. Baseline characteristics, hemodynamic variables at RRT initiation, and NT-proBNP level before surgery, at RRT initiation, and on the first day after RRT were collected. The primary outcome was 28-day mortality after RRT initiation. Results: Serum NT-proBNP levels in non-survivors was markedly higher than survivors before surgery (median: 4,096 [IQR, 962.0-9583.8] vs. 1,339 [IQR, 446-5,173] pg/mL; P < 0.01), at RRT initiation (median: 10,366 [IQR, 5,668-20,646] vs. 3,779 [IQR, 1,799-11,256] pg/mL; P < 0.001), and on the first day after RRT (median: 9,055.0 [IQR, 4,392-24,348] vs. 5,255 [IQR, 2,134-9,175] pg/mL; P < 0.001). The area under the receiver operating characteristic curve of NT-proBNP before surgery, at RRT initiation, and on the first day after RRT for predicting 28-day mortality was 0.64 (95% CI, 0.55-0.73), 0.71 (95% CI, 0.63-0.79), and 0.68 (95% CI, 0.60-0.76), respectively. Consistently, Cox regression revealed that NT-proBNP levels before surgery (HR: 1.27, 95% CI, 1.06-1.52), at RRT initiation (HR: 1.11, 95% CI, 1.06-1.17), and on the first day after RRT (HR: 1.17, 95% CI, 1.11-1.23) were independently associated with 28-day mortality. Conclusions: Serum NT-proBNP was an independent predictor of 28-day mortality in cardiac surgical patients with AKI requiring RRT. The prognostic role of NT-proBNP needs to be confirmed in the future.

Changes in Stroke Volume Variation Induced by Passive Leg Raising to Predict Fluid Responsiveness in Cardiac Surgical Patients With Protective Ventilation.

OBJECTIVES: Stroke volume variation (SVV) has been used to predict fluid responsiveness. The authors hypothesized the changes in SVV induced by passive leg raising (PLR) might be an indicator of fluid responsiveness in patients with protective ventilation after cardiac surgery. DESIGN: A prospective single-center observational study. SETTING: A single cardiac surgery intensive care unit at a tertiary hospital. PARTICIPANTS: A total of 123 patients undergoing cardiac surgery with hemodynamic instability. Tidal volume was set between 6 and 8 mL/kg of ideal body weight. INTERVENTIONS: PLR maneuver, fluid challenge. MEASUREMENTS AND MAIN RESULTS: SVV was continuously recorded using pulse contour analysis before and immediately after a PLR test and after fluid challenge (500 mL of colloid given over 30 min). Sixty-three (51.22%) patients responded to fluid challenge, in which PLR and fluid challenge significantly increased the SV and decreased the SVV. The decrease in SVV induced by PLR was correlated with the SV changes induced by fluid challenge. A 4% decrease in the SVV induced by PLR-discriminated responders to fluid challenge with an area under the curve of 0.90. The gray zone identified a range of SVV changes induced by PLR (between -3.94% and -2.91%) for which fluid responsiveness could not be predicted reliably. The gray zone included 15.45% of the patients. The SVV at baseline predicted fluid responsiveness with an area under the curve of 0.72. CONCLUSIONS: Changes in the SVV induced by PLR predicted fluid responsiveness in cardiac surgical patients with protective ventilation.

Preemptive renal replacement therapy in post-cardiotomy cardiogenic shock patients: a historically controlled cohort study.

BACKGROUND: The aim of the study was to evaluate whether the preemptive renal replacement therapy (RRT) might improve outcomes in post-cardiotomy cardiogenic shock (PCCS) patients. METHODS: In Period A (September 2014-April 2016), patients with PCCS received RRT, depending on conventional indications or bedside attendings. In Period B (May 2016-November 2017), the preemptive RRT strategy was implemented in all PCCS patients in our intensive care unit. The goal-directed RRT was applied for the RRT patients. The hospital mortality and renal recovery were compared between the two periods. RESULTS: A total of 155 patients (76 patients in Period A and 79 patients in Period B) were ultimately enrolled in this study. There were no significant differences in demographic characteristics and intraoperative and postoperative parameters between the two groups. The duration between surgery and RRT initiation was significantly shorter in Period B than in Period A [23 (17, 66) vs. 47 (20, 127) h, P<0.01]. The hospital mortality in Period B was significantly lower than that in Period A (38.0% vs. 59.2%, P<0.01). There were fewer patients with no renal recovery in Period B (4.1% vs. 19.4%, P=0.026). Patients in Period B displayed a significantly shorter time to completely renal recovery (12±15 vs. 25±15 d, P<0.05). CONCLUSIONS: Among PCCS patients, preemptive RRT compared with conventional initiation of RRT reduced mortality in hospital and also led to faster and more frequent recovery of renal function. Our preliminary study supposed that preemptive initiation of RRT might be an effective approach to PCCS with acute kidney injury (AKI).

Initial clinical impact of inhaled nitric oxide therapy for refractory hypoxemia following type A acute aortic dissection surgery.

BACKGROUND: To evaluate the effect of inhaled nitric oxide (iNO) therapy on oxygenation and clinical outcomes in patients with refractory hypoxemia after surgical reconstruction for acute type A aortic dissection (TAAD). METHODS: A before-and-after interventional study was conducted in patients with refractory hypoxemia after surgical reconstruction for TAAD. Postoperative refractory hypoxemia was defined as a persistent PaO2/FiO2 ratio ≤100 mmHg despite conventional therapy. From January to November 2016, conventional treatment was carried out for refractory hypoxemia. From December 2016 to October 2017, on the basis of conventional therapy, we explored the use of iNO to treat refractory hypoxemia. RESULTS: Fifty-three TAAD patients with refractory hypoxemia were enrolled in this study. Twenty-seven patients received conventional treatment (conventional group), while the remaining 26 patients received iNO therapy. The PaO2/FiO2 ratio was significantly higher in the iNO group after treatment than in the conventional group when analyzed over the entire 72 hours. The duration of invasive mechanical ventilation was significantly reduced in the iNO group (69.19 vs. 104.56 hours; P=0.003). Other outcomes, such as mortality (3.85% vs. 7.41%, P=1.000), intensive care unit (ICU) duration (9.88 vs. 12.36 days, P=0.059) and hospital stay (16.88 vs. 20.76 days, P=0.060), were not significantly different between the two groups. CONCLUSIONS: iNO therapy might play an ameliorative role in patients with refractory hypoxemia after surgical reconstruction for TAAD. This therapy may lead to sustained improvement in oxygenation and reduce the duration of invasive mechanical ventilation.

Reliability of three-dimensional color flow Doppler and two-dimensional pulse wave Doppler transthoracic echocardiography for estimating cardiac output after cardiac surgery.

BACKGROUND: Three-dimensional color flow Doppler (3DCF) is a new convenient technique for cardiac output (CO) measurement. However, to date, no one has evaluated the accuracy of 3DCF echocardiography for CO measurement after cardiac surgery. Therefore, this single-center, prospective study was designed to evaluate the reliability of three-dimensional color flow and two-dimensional pulse wave Doppler (2D-PWD) transthoracic echocardiography for estimating cardiac output after cardiac surgery. METHODS: Post-cardiac surgical patients with a good acoustic window and a low dose or no dose of vasoactive drugs (norepinephrine < 0.05 µg/kg/min) were enrolled for CO estimation. Three different methods (third generation FloTrac/Vigileo™ [FT/V] system as the reference method, 3DCF, and 2D-PWD) were used to estimate CO before and after interventions (baseline, after volume expansion, and after a dobutamine test). RESULTS: A total of 20 patients were enrolled in this study, and 59 pairs of CO measurements were collected (one pair was not included because of increasing drainage after the dobutamine test). Pearson's coefficients were 0.260 between the CO-FT/V and CO-PWD measurements and 0.729 between the CO-FT/V and CO-3DCF measurements. Bland-Altman analysis showed the bias between the absolute values of CO-FT/V and CO-PWD measurements was - 0.6 L/min with limits of agreement between - 3.3 L/min and 2.2 L/min, with a percentage error (PE) of 61.3%. The bias between CO-FT/V and CO-3DCF was - 0.14 L/min with limits of agreement between - 1.42 L /min and 1.14 L/min, with a PE of 29.9%. Four-quadrant plot analysis showed the concordance rate between ΔCO-PWD and ΔCO-3FT/V was 93.3%. CONCLUSIONS: In a comparison with the FT/V system, 3DCF transthoracic echocardiography could accurately estimate CO in post-cardiac surgical patients, and the two methods could be considered interchangeable. Although 2D-PWD echocardiography was not as accurate as the 3D technique, its ability to track directional changes was reliable.

Internal jugular vein variability predicts fluid responsiveness in cardiac surgical patients with mechanical ventilation.

BACKGROUND: To evaluate the efficacy of using internal jugular vein variability (IJVV) as an index of fluid responsiveness in mechanically ventilated patients after cardiac surgery. METHODS: Seventy patients were assessed after cardiac surgery. Hemodynamic data coupled with ultrasound evaluation of IJVV and inferior vena cava variability (IVCV) were collected and calculated at baseline, after a passive leg raising (PLR) test and after a 500-ml fluid challenge. Patients were divided into volume responders (increase in stroke volume ≥ 15%) and non-responders (increase in stroke volume < 15%). We compared the differences in measured variables between responders and non-responders and tested the ability of the indices to predict fluid responsiveness. RESULTS: Thirty-five (50%) patients were fluid responders. Responders presented higher IJVV, IVCV and stroke volume variation (SVV) compared with non-responders at baseline (P < 0.05). The relationship between IJVV and SVV was moderately correlated (r = 0.51, P < 0.01). The areas under the receiver operating characteristic (ROC) curves for predicting fluid responsiveness were 0.88 (CI 0.78-0.94) for IJVV compared with 0.83 (CI 0.72-0.91), 0.97 (CI 0.89-0.99), 0.91 (CI 0.82-0.97) for IVCV, SVV, and the increase in stroke volume in response to a PLR test, respectively. CONCLUSIONS: Ultrasound-derived IJVV is an accurate, easily acquired noninvasive parameter of fluid responsiveness in mechanically ventilated postoperative cardiac surgery patients, with a performance similar to that of IVCV.

Glucocorticoid attenuates acute lung injury through induction of type 2 macrophage.

BACKGROUND: Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are severe inflammatory lung diseases. Methylprednisolone (MP) is a common drug against inflammation in clinic. In this study, we aim to investigate the protective effect of MP on ALI and potential mechanisms. METHODS: Male BABL/c mice were injected through tail vein using lipopolysaccharide (LPS, 5 mg/kg) with or without 5 mg/kg MP. Lung mechanics, tissue injury and inflammation were examined. Macrophage subsets in the lung were identified by flow cytometry. Macrophages were cultured from bone marrow of mice with or without MP. Then, we analyzed and isolated the subsets of macrophages. These isolated macrophages were then co-cultured with CD4+ T cells, and the percentage of regulatory T cells (Tregs) was examined. The expression of IL-10 and TGF-ß in the supernatant was measured. The Tregs immunosuppression function was examined by T cell proliferation assay. To disclose the mechanism of the induction of Tregs by M2c, we blocked IL-10 or/and TGF-ß using neutralizing antibody. RESULTS: Respiratory physiologic function was significantly improved by MP treatment. Tissue injury and inflammation were ameliorated in the MP-treated group. After MP treatment, the number of M1 decreased and M2 increased in the lung. In in vitro experiment, MP promoted M2 polarization rather than M1. We then induced M1, M2a and M2c from bone marrow cells. M1 induced more Th17 while M2 induced more CD4+CD25+Fxop3+ Tregs. Compared with M2a, M2c induced more Tregs, and this effect could be blocked by anti-IL-10 and anti-TGF-ß antibodies. However, M2a and M2c have no impact on Tregs immunosuppression function. CONCLUSION: In conclusion, MP ameliorated ALI by promoting M2 polarization. M2, especially M2c, induced Tregs without any influence on Tregs immunosuppression function.

Early Kinetics of Procalcitonin in Predicting Surgical Outcomes in Type A Aortic Dissection Patients.

BACKGROUND: In cardiac surgery, elevation of procalcitonin (PCT) could be observed postoperatively in the absence of any evidence of infection and also seems to be a prognostic marker. PCT levels measured in patients undergoing Type A aortic dissection (TAAD) were used to determine prognostic values for complications and surgical outcomes. METHODS: Measurements of PCT, C-reactive protein (CRP), and leukocyte count were observed in TAAD surgery patients (n = 251; average age: 49.02 ± 12.83 years; 78.5% male) at presurgery (T0) and 24 h (T1), 48 h (T2), and 7 days (T3) postsurgery. PCT clearance (PCTc) on days 2 and 7 was calculated: (PCTday1- PCTday2/day7)/PCTday1 × 100%. Endotracheal intubation duration, length of stay (LOS) in the Intensive Care Unit (ICU)/hospital, and complications were recorded. RESULTS: PCT peaked 24 h postsurgery (median 2.73 ng/ml) before decreasing. Correlation existed between PCT levels at T1 and duration of cardiopulmonary bypass (P = 0.001, r = 0.278). Serum PCT concentrations were significantly higher in nonsurvivor and multiple organ dysfunction syndrome groups on all postoperative days. PCT levels at T1 correlated with length of time of ventilation support and ICU/hospital LOS. Comparing PCT values of survivors versus nonsurvivors, a PCT cutoff level of 5.86 ng/ml at T2 had high sensitivity (70.6%) and specificity (74.3%) in predicting in-hospital death. PCTc-day 2 and 7 were significantly higher in survivor compared with nonsurvivor patients (38% vs. 8%, P= 0.012, 83% vs. -39%, P< 0.001). A PCTc-day 7 cutoff point of 48.7% predicted survival with high sensitivity (77.8%) and specificity (81.8%). CONCLUSIONS: PCT level and PCTc after TAAD surgery might serve as early prognostic markers to predict postoperative outcome. PCT measurement may help identify high-risk patients.

Analgesic efficacy and quadriceps strength of adductor canal block versus femoral nerve block following total knee arthroplasty.

PURPOSE: Femoral nerve blocks (FNBs) provide effective analgesia after total knee arthroplasty, but have been associated with quadriceps weakness. Adductor canal block (ACB) is a promising alternative option that delivers a primarily sensory blockade. The aim of this study was to determine whether ACB provides superior quadriceps strength and similar pain control than FNB. METHODS: A systematic search of PubMed, the Cochrane Library, EMBASE and Web of Science was conducted without publication data or language restriction. Comparative studies comparing ACB with FNB were included. Two authors independently assessed data extraction and quality of the studies. RESULTS: Nine studies with 639 patients were identified. Results of meta-analysis showed that compared with FNB, ACB preserved quadriceps muscle strength better than FNB [MD24h = 1.14, 95 % CI (0.38, 1.91), p < 0.01; MD48h = 0.40, 95 % CI (0.16, 0.64), p < 0.01], while there were no significant differences in pain score during rest at 24 h [SMD = - 0.04, 95 % CI (-0.17, 0.26); n.s] or 48 h [SMD = - 0.10, 95 % CI (-0.27, 0.08); n.s], pain score during activity at 24 h [SMD = 0.13, 95 % CI (-0.36, 0.62); n.s] or 48 h [SMD = - 0.13, 95 % CI (-0.37, 0.12); n.s], opioid consumption at 24 h [SMD = - 0.01, 95 % CI (-1.68, 1.66); n.s] or 48 h [SMD = - 0.92, 95 % CI (-6.86, 5.01); n.s], length of hospital stay [MD = 0.05, 95 % CI (-0.91, 1.00); n.s] and nausea or vomiting [RR = 1.17, 95 % CI (0.62, 2.20); n.s] between ACB and FNB. CONCLUSIONS: ACB preserved the strength of quadriceps more than FNB and achieves similar analgesic effects in post-operative pain. LEVEL OF EVIDENCE: Level III.

[Measurement of serum free light chains and its clinical significance in 20 newly diagnosed patients of multiple myeloma].

The objective of this study was to explore the clinical significance of measuring serum free light chains (sFLC) and to compare with serum total light chains (free and binded) in multiple myeloma (MM). sFLC in 20 newly diagnosed MM patients and 20 cases of healthy people as control were measured by immuno-nephelometric assays; the serum light chains and kappa/lambda ratio were measured in all patients, while immunofixation electrophoresis (IFE) tests were carried out at the same time in 18 out of 20 patients. The results showed that the abnormality of serum free light chains and kappa/lambda ratio were found in all of the 20 newly diagnosed MM patients (p < 0.01). The measurement of sFLC showed higher sensitivity than the total serum chains (p < 0.01). It is concluded that the method testing sFLC by immuno-nephelometric assay combined with kappa/lambda ratio is valuable for MM diagnosis, and the measurement of sFLC can be used as one of indicators for MM diagnosis.