The Neutrophil-to-Lymphocyte Ratio as a Predictor of Postoperative Outcomes in Patients Undergoing Coronary Artery Bypass Grafting.

Background: The neutrophil-to-lymphocyte ratio (NLR) has been suggested as a novel predictive marker of cardiovascular disease. However, its prognostic role in patients undergoing coronary artery bypass grafting (CABG) is unclear. This study aimed to determine the association between the preoperative NLR and early mortality in patients undergoing CABG. Methods: Cardiac surgery was performed in 2,504 patients at Seoul St. Mary's Hospital from January 2010 to December 2021. This study retrospectively reviewed 920 patients who underwent isolated CABG, excluding those for whom the preoperative NLR was unavailable. The primary endpoints were the 30- and 90-day mortality after isolated CABG. Risk factor analysis was performed using logistic regression analysis. Based on the optimal cut-off value of preoperative NLR on the receiver operating characteristic curve, high and low NLR groups were compared. Results: The 30- and 90-day mortality rates were 3.8% (n=35) and 7.0% (n=64), respectively. In the multivariable analysis, preoperative NLR was significantly associated with 30-day mortality (odds ratio [OR], 1.28; 95% confidence interval [CI], 1.17-1.39; p<0.001) and 90-day mortality (OR, 1.17; 95% CI, 1.07-1.28; p<0.001). The optimal cut-off value of the preoperative NLR was 3.4. Compared to the low NLR group (<3.4), the high NLR group (≥3.4) showed higher 30- and 90-day mortality rates (1.4% vs. 12.1%, p<0.001; 2.8% vs. 21.3%, p<0.001, respectively). Conclusion: Preoperative NLR was strongly associated with early mortality after isolated CABG, especially in patients with a high preoperative NLR (≥3.4). Further studies with larger cohorts are necessary to validate these results.

Evolocumab administration prior to Coronary Artery Bypass Grafting in patients with multivessel coronary artery disease (EVOCABG): study protocol for a randomized controlled clinical trial.

BACKGROUND: Despite advances in surgical and postoperative care, myocardial injury or infarction (MI) is still a common complication in patients undergoing coronary artery bypass surgery (CABG). Several studies that aimed to reduce postoperative myocardial injury, including those investigating statin loading, have been conducted but did not indicate any clear benefits. Evolocumab, a PCSK9 inhibitor, has been reported to lower lipids and prevent ischemic events in various medical conditions. However, the effect of evolocumab in cardiovascular surgery has not been evaluated. The objective of this trial is to evaluate the cardioprotective effects of evolocumab in elective CABG patients with multivessel coronary artery disease. METHODS: EVOCABG is a prospective, randomized, open, controlled, multicenter, superiority, phase III clinical trial. Patients with multivessel coronary artery disease without initial cardiac enzyme elevation will be recruited (n=100). Participants will be randomly allocated into two groups: a test group (evolocumab (140mg) administration once within 72 h before CABG) and a control group (no administration). The primary outcome is the change in peak levels of serum cardiac marker (troponin-I) within 3 days of CABG surgery compared to the baseline. Secondary outcomes include post-operative clinical events including death, myocardial infarction, heart failure, stroke, and atrial fibrillation. DISCUSSION: This trial is the first prospective randomized controlled trial to demonstrate the efficacy of evolocumab in reducing ischemic-reperfusion injury in patients undergoing CABG. This trial will provide the first high-quality evidence for preoperative use of evolocumab in mitigating or preventing ischemic-reperfusion-related myocardial injury during the surgery. TRIAL REGISTRATION: Clinical Research Information Service (CRIS) of the Republic of Korea KCT0005577 . Registered on 4 November 2020.

Intraoperative Glycemic Variability and Mean Glucose are Predictors for Postoperative Delirium After Cardiac Surgery: A Retrospective Cohort Study.

PURPOSE: Postoperative delirium (POD) is a common but serious complication after cardiac surgery and is associated with various short- and long-term outcomes. In this study, we investigated the effects of intraoperative glycemic variability (GV) and other glycemic variables on POD after cardiac surgery. PATIENTS AND METHODS: A retrospective single-center cohort analysis was conducted using data from electronic medical record from 2018 to 2020. A total of 705 patients undergoing coronary artery bypass graft surgery and/or valve surgery, and/or aortic replacement surgery were included in the analysis. Intraoperative GV was assessed with a coefficient of variation (CV), which was defined as the standard deviation of five intraoperative blood glucose measurements divided by the mean. POD assessment was performed three times a day in the ICU and twice a day in the ward until discharge by trained medical staff. POD was diagnosed if any of the Confusion Assessment Method for the Intensive Care Unit was positive in the ICU, and the Confusion Assessment Method was positive in the ward. Multivariable logistic regression was used to identify associations between intraoperative GV and POD. RESULTS: POD occurred in 306 (43.4%) patients. When intraoperative glycemic CV was compared as a continuous variable, the delirium group had higher intraoperative glycemic CV than the non-delirium group (22.59 [17.09, 29.68] vs 18.19 [13.00, 23.35], p < 0.001), and when intraoperative glycemic CV was classified as quartiles, the incidence of POD increased as intraoperative glycemic CV quartiles increased (first quartile 29.89%; second quartile 36.67%; third quartile 44.63%; and fourth quartile 62.64%, p < 0.001). In the multivariable logistic regression model, patients in the third quartile of intraoperative glycemic CV were 1.833 times (OR 1.833, 95% CI: 1.132-2.967, p = 0.014), and patients in the fourth quartile of intraoperative glycemic CV were 3.645 times (OR 3.645, 95% CI: 2.235-5.944, p < 0.001) more likely to develop POD than those in the first quartile of intraoperative glycemic CV. CONCLUSION: Intraoperative blood glucose fluctuation, manifested by intraoperative GV, is associated with POD after cardiac surgery. Patients with a higher intraoperative GV have an increased risk of POD.

Risk factors for Takotsubo syndrome following cardiac surgery: A case-control study.

OBJECTIVE: Takotsubo syndrome following cardiac surgery is a rare occurrence. However, early diagnosis is essential to prevent treatment which could increase the left ventricular outflow tract pressure gradient in patients with Takotsubo syndrome, and lead to cardiogenic shock. Therefore, our study aimed to identify the incidence of Takotsubo syndrome after cardiopulmonary bypass and the associated risk factors and prognosis. METHODS: We retrospectively studied 5773 patients who underwent cardiopulmonary bypass between February 2007 and July 2017. Among these, Takotsubo syndrome was diagnosed in 52 (0.9%). To evaluate the risk factors for Takotsubo syndrome, 104 of the remaining 5721 patient were randomly selected as the control group (1:2 ratio). Univariate and multivariate logistic regression analyses were used for risk factor analysis. RESULTS: Majority of patients (69.2%) in the Takotsubo syndrome group underwent mitral valve surgery, compared with 32.7% in the control group. The following risk factors of Takotsubo syndrome were identified: atrio-ventricular valve surgery (odds ratio (OR) 10.5; 95% confidence interval (CI), 2.6-42.5; p = 0.001); and the immediate postoperative use of epinephrine (OR, 3.3; 95% CI, 1.0-10.7; p = 0.05) and dobutamine (OR, 4.8; 95% CI, 1.72-13.3; p = 0.003). Hypertension was a significant protective factor against Takotsubo syndrome following cardiac surgery (OR, 0.22; 95% CI, 0.06-0.73; p = 0.01). CONCLUSION: Takotsubo syndrome following cardiac surgery is rare. Immediate postoperative use of epinephrine and doputamine, as well as atrio-ventricular valve surgery were factors associated with the development of Takotsubo syndrome.

Effect of the Proximal Anastomosis Configuration of the Radial Artery in Patients Undergoing Coronary Artery Bypass Grafting.

BACKGROUND: Several factors, such as the degree of target vessel stenosis, are known to be associated with radial artery (RA) graft patency in coronary artery bypass grafting (CABG). There is a lack of data regarding the effect of the RA proximal configuration (aortic anastomosis versus T-anastomosis). This study evaluated the effects of the RA proximal configuration on the patency rate and clinical outcomes after CABG. METHODS: We conducted a retrospective study, analyzing 328 patients who had undergone CABG with an RA graft. We divided the patients into 2 groups. The primary endpoint was RA patency and the secondary endpoints were overall mortality and major adverse cardiac and cerebrovascular events (MACCE). We performed a propensity score-matched comparison. RESULTS: Aorta-RA anastomosis was performed in 275 patients, whereas the rest of the 53 patients received T-RA anastomosis. The mean age was 67.3±8.7 years in the T-RA anastomosis group and 63.8±9.5 years in the aorta-RA anastomosis group (p=0.02). The mean follow-up duration was 5.13±3.07 years. Target vessel stenosis ≥70% (hazard ratio [HR], 0.42; 95% confidence interval [CI], 0.20-0.91; p=0.03) and T-RA anastomosis configuration (HR, 2.34; 95% CI, 1.01-5.19; p=0.04) were significantly associated with RA occlusion in the multivariable analysis. However, T-RA anastomosis was not associated with higher risks of overall mortality and MACCE following CABG (p=0.30 and p=0.07 in the matched group, respectively). CONCLUSION: Aorta-RA anastomosis showed a superior patency rate compared to T-RA anastomosis. However, the RA proximal anastomosis configuration was not associated with mortality or MACCE.

B-type natriuretic peptide as a surrogate marker for survival in patients undergoing cardiac surgery.

BACKGROUND: B-type natriuretic peptide (BNP) is a biomarker predicting morbidity and mortality in patients with congestive heart failure. However, the usefulness of pre- or postoperative BNP levels in patients undergoing cardiac surgery remains uncertain. We sought to determine the association of pre- or postoperative BNP levels on mortality in patients undergoing cardiac surgery under cardiopulmonary bypass (CPB). METHODS: This study retrospectively evaluated 1,642 patients undergoing cardiac surgery under CPB over 2 years. The primary outcomes were 30-day and overall mortality after cardiac surgery. RESULTS: The 30-day mortality rate was 3.0% (n=49), and the overall mortality occurred in 118 patients during the mean follow-up period of 24.9±8.9 months. In multivariable analyses, preoperative BNP level was not significantly associated with 30-day [odds ratio (OR), 1.03; 95% confidence interval (CI), 0.99-1.06; P=0.06] or overall [hazard ratio (HR), 1.01; 95% CI, 0.98-1.03; P=0.50] mortalities. However, the postoperative BNP level was significantly associated with 30-day (OR, 1.05; 95% CI, 1.02-1.09; P=0.001) and overall (HR, 1.03; 95% CI, 1.01-1.04; P=0.01) mortalities. As a sensitivity analysis, postoperative BNP levels were divided into quartiles. The top quartile (≥484 pg/mL) was identified as a strong predictor of overall mortality (HR, 2.18; 95% CI, 1.14-4.19; P=0.02). CONCLUSIONS: Preoperative BNP level was not associated with mortality after cardiac surgery. However, postoperative BNP level was associated with mortality after cardiac surgery, especially in patients with high levels (≥484 pg/mL). Further studies in larger cohorts are necessary to validate these results.

Effect of revascularization on coronary chronic total occlusion in patients undergoing coronary artery bypass grafting.

BACKGROUND: Bypass grafting for chronic total occlusions (CTOs) remains surgically challenging and controversial. Therefore, we evaluated the incidence and clinical outcomes of revascularization on CTOs undergoing coronary artery bypass grafting (CABG). METHODS: Among 828 patients who underwent isolated CABG from January 2010 to December 2018, 245 patients (29.6%) diagnosed with at least one CTO were included and retrospectively reviewed. Primary endpoints were 30-day and overall mortality. Secondary endpoint was the composite outcome of major adverse cardiac and cerebrovascular events (MACCE). RESULTS: With a mean follow-up of 56.6±6.5 months in 245 patients with CTOs, 51 patients (20.8%) received incomplete revascularization (ICR) for CTO lesions. Risk factor analysis showed that ICR was associated with increased 30-day [odds ratio 8.62; 95% confidence interval (CI): 1.64-50; P=0.011] and overall mortality (hazard ratio (HR) 2.13; 95% CI: 1.07-4.21; P=0.03). ICR also increased the risk of MACCE (HR 1.98; 95% CI: 1.12-3.54; P=0.01). Freedom from overall mortality was 92.8%, 90.4%, and 86.8% in the complete revascularization group, and 86.3%, 80.0%, and 72.7% in the ICR group, at 1, 3, and 5 years, respectively (P=0.004). CONCLUSIONS: In patients with CTOs undergoing CABG, the rate of ICR was 20.8%, and it significantly increased the risk of mortality and MACCE. Further studies in a large cohort are needed.

Impact of 6% balanced hydroxyethyl starch following cardiopulmonary bypass on renal function: a retrospective study.

BACKGROUND: We aimed to evaluate the effect of limited volume of hydroxyethyl starch (HES) administration on postoperative renal function in patients undergoing cardiac surgery under cardiopulmonary bypass (CPB). METHODS: One thousand six hundred fifty-seven patients undergoing cardiac surgery under CPB over two years were included. The patients were divided according to the amount of HES administrated during the first 2 days post-surgery; moderate dose HES (≥20 ml/kg) versus low dose HES (< 20 ml/kg). Outcomes were compared by using inverse probability weighting. RESULTS: Incidence of acute kidney injury (AKI) was higher in the moderate HES group (p = .02). However, new renal replacement therapy (RRT) (P = .30) and early mortality (p = .97) was similar between the groups. When adjusted, the moderate HES use was associated with AKI (OR, 1.66; 95% CI, 1.12-2.44; p = .01), but did not increase the risk of new RRT (OR, 1.27; 95% CI, 0.71-2.18; p = .40) or early mortality (HR, 0.73; 95% CI, 0.29-1.81; p = .50). CONCLUSIONS: The moderate dose administration of HES (≥20 ml/kg) in the postoperative period following cardiac surgery might be associated with the risk of AKI. However, it was not associated with serious adverse outcomes such as new RRT or mortality. Further randomized controlled studies are needed to validate study results.

Management of Atrio-esophageal Fistula Induced by Radiofrequency Catheter Ablation in Atrial Fibrillation Patients: a Case Series.

Atrio-esophageal fistula (AEF) is one of the most devastating complication of radiofrequency catheter ablation (RFCA) of atrial fibrillation (AF) and surgical repair is strongly recommended. However, optimal surgical approach remains to be elucidated. We retrospectively reviewed AEF cases that occurred after RFCA in a single center and evaluated the clinical results of different surgical approach. Surgical or endoscopic repair was attempted in five AF patients who underwent RFCA. Atrio-esophageal fistula and mediastinal infection was not controlled in the patient who underwent endoscopic repair eventually died. Lethal cerebral air embolism occurred two days after surgery in a patient who underwent esophageal repair only. Primary surgical repair of both the left atrium (LA) and esophagus was performed in the remaining three patients. Among these three patients, two underwent external LA repair and the remaining had internal LA repair via open-heart surgery. External repair of the LA was unsuccessful and one patient dies and another had to undergo second operation with internal repair of the LA. The patient who underwent internal LA repair during the first operation survived without additional surgery. Furthermore, we applied veno-arterial extracorporeal membrane oxygenation (VA-ECMO) with artificial induction of ventricular fibrillation in this patient to prevent air and septic embolism and she had no neurologic sequelae. In summary, surgical correction can be considered preferentially to correct AEF. Open-heart surgical repair of LA from the internal side seems to be an acceptable surgical method. Application of VA-ECMO with artificial induction of ventricular fibrillation might be effective to prevent air and septic embolism.

Influence of a high-intensity staffing model in a cardiac surgery intensive care unit on postoperative clinical outcomes.

OBJECTIVE: Various staffing models have been applied in intensive care units (ICUs) to improve outcomes. However, there is a lack of evidence regarding the effect of staffing models in cardiac surgery ICUs. Thus, we aimed to evaluate the efficacy of high-intensity staffing in cardiac surgery ICUs. METHODS: From January 2013 to December 2016, 4676 adult patients were admitted to our cardiac surgery ICU after surgery. Excluding patients undergoing minor surgery or noncardiac-related surgery, 4038 patients were analyzed. Beginning in January 2015, patients were divided into low-intensity group (n = 1784) and high-intensity group (n = 2254) according to the study period. Primary outcomes were ICU and hospital length of stay, rates of transfusion and infection, and readmission to the ICU. Secondary outcomes were 30-day and ICU mortality. To reduce potential confounders, propensity score-matched analysis was performed. RESULTS: In the high-intensity group, ICU and hospital length of stay were significantly shorter (P < .001). Incidence of readmission was lower in the high-intensity group (3.1% vs 12.5%; P < .05). Infection rate in respiratory tract and bloodstream was lower in the high-intensity group (3.1% vs 5.0%; P < .05). Transfusion rate and amount were also significantly lower in the high-intensity group (P < .05). However, 30-day (1.9% vs 2.1%; P = .71) and ICU mortality (2.1% vs 2.7%; P = .31) were comparable between the groups. CONCLUSIONS: High-intensity staffing model during daytime hours by cardiac surgery intensivists significantly improved ICU-related outcomes. However, high-intensity staffing did not affect early mortality after cardiac surgery.

Rescue Extracorporeal Bypass to Prevent Atrioesophageal Fistula-related Air Embolism.

Atrioesophageal fistula (AEF) is a rare but disastrous complication encountered after radiofrequency catheter ablation for atrial fibrillation or flutter. Furthermore cerebral air embolism due to AEF is considered a strong predictor of mortality. In our case a patient presented with AEF and cerebral air embolism. As a rescue effort ventricular fibrillation was induced and sustained under venoarterial extracorporeal membrane oxygenation support until emergency AEF repair was feasible. Herein we report the successful use of the above measures to prevent further air embolism in a patient with radiofrequency catheter ablation-related AEF.

Impact of resection margin length and tumor depth on the local recurrence after thoracoscopic pulmonary wedge resection of a single colorectal metastasis.

BACKGROUND: To evaluate the influence of tumor depth on preoperative computed tomography (CT) image, and resection margin length on local recurrence after pulmonary metastasectomy of colorectal cancer. METHODS: Patients undergoing thoracoscopic pulmonary wedge resection for single pulmonary metastasis of colorectal cancer origin from 2007 to 2017 were analyzed. Factors such as resection margin, tumor size and depth were analyzed. The local recurrences of two subgroups based on the pulmonary resection margin (Group 1: resection margin 1-10 mm or shorter than the tumor size, Group 2: resection margin >10 mm or at least greater than the tumor size) were analyzed. RESULTS: Sixty-five patients were included in this study. The local recurrence rate was 12/65 (18.5%). Median follow up period was 33 months. Median tumor size and depth on preoperative CT were 1.1 and 1.6 cm. Median length of resection margin was 0.5 cm (group 1: 0.4 cm, group 2: 1.0 cm, P<0.001). No difference was noted in 3-year local recurrence-free survival (80.8% vs. 76.7%, P=0.756) between the two subgroups. No significant correlation was noted between the length of resection margin and the tumor size and depth. However, tumor depth was an independent factor related to higher local recurrence on multivariate analysis. CONCLUSIONS: Extent of resection margin in pulmonary metastasectomy does not seem to affect significantly on the local recurrence if complete resection is accomplished. However, preoperative tumor depth on CT image and postoperative distant metastasis seem to affect on local recurrence after pulmonary metastasectomy.

Efficacy of left heart decompression during extracorporeal membrane oxygenation: a case-control study.

BACKGROUND: Veno-arterial (VA) extracorporeal membrane oxygenation (ECMO) is used in various cardiogenic shocks. In severe myocardial dysfunction, left heart (LH) distension may occur and aggravate pulmonary edema. Despite the recent case reports on various venting catheter insertion methods for LH decompression, the necessity and efficacy of LH venting procedure are still controversial. Therefore, we focused on evaluating efficacy of LH venting catheter insertion for LH decompression. METHODS: In total, 373 patients received VA ECMO at our institution from May 2012 to January 2016. Of these, 25 patients underwent LH venting catheter insertion. Indication for the procedure included pulmonary congestion observed on chest radiogram, with arterial pulse pressure ≤10 mmHg. The control group comprised of 45 patients with peripheral VA ECMO having arterial pulse pressure ≤ for ≥24 hours during the same study period who did not undergo LH venting procedure. Finally, 70 patients were compared and analyzed. RESULTS: Mean age of the patients was 52.6±17.1 years. The ECMO running time in each group was 7.2±7.1 days in the vent (-) group and 9.2±8.5 days in the vent (+) group. Successful weaning rate was higher in the LH vent (+) group (P=0.08). Moreover, LH venting catheter insertion was identified as a predictor of weaning success with marginal significance (OR =2.47; 95% CI: 0.90-6.72; P=0.07). CONCLUSIONS: LH decompression by venting catheter insertion in patients on VA ECMO may be more effective and helpful for successful ECMO weaning than conventional medical management without survival benefit.

Central Extracorporeal Membrane Oxygenation for Bridging of Right-Sided Heart Failure to Lung Transplantation: A Single-Center Experience and Literature Review.

OBJECTIVE: Right-sided heart failure develops in lung transplantation candidates on prolonged peripheral extracorporeal membrane oxygenation support and is a major determinant of mortality. The use of central venoarterial extracorporeal membrane oxygenation for bridging of right-sided heart failure to lung transplantation was evaluated. DESIGN: Retrospective case series and literature review. SETTING: A single tertiary care university hospital. PARTICIPANTS: The study comprised lung transplantation candidates on extracorporeal membrane oxygenation bridging who developed right-sided heart failure. INTERVENTIONS: Central venoarterial extracorporeal membrane oxygenation. MEASUREMENTS AND MAIN RESULTS: Of 6 patients who underwent the study protocol, 3 were bridged successfully to lung transplantation and 1 was bridged to recovery. CONCLUSIONS: The study demonstrates that central extracorporeal membrane oxygenation may be a feasible option for bridging of right-sided heart failure to lung transplantation.

Extracorporeal Life Support in Adult Patients with Hematologic Malignancies and Acute Circulatory and/or Respiratory Failure.

BACKGROUND: The primary goal of this study was to characterize the clinical outcomes of adult patients with hematologic malignancies (HM) who were treated with extracorporeal membrane oxygenation (ECMO) support when conventional treatments failed. METHODS: In this retrospective, observational study at a tertiary medical center, we reviewed the clinical course of 23 consecutive patients with HM requiring ECMO who were admitted to the intensive care unit at Asan Medical Center from March 2010 to April 2015. RESULTS: A total of 23 patients (8 female; median age, 44 years; range, 29-51 years) with HM and severe acute circulatory and/or respiratory failure received ECMO therapy during the study period. Fourteen patients received veno-arterial ECMO, while 9 patients received veno-venous ECMO. The median ECMO duration was 104.7 hours (range, 37.1-221 hours). Nine patients were successfully weaned from ECMO. The in-hospital mortality rate was 91.1% (21 of 23). There were complications in 3 patients (cannulation site bleeding, limb ischemia, and gastrointestinal bleeding). CONCLUSION: ECMO is a useful treatment for patients with circulatory and/or pulmonary failure. However, in patients with HM, the outcomes of ECMO treatment results were very poor, so it is advisable to carefully decide whether to apply ECMO to these patients.

Extracorporeal life support for adults with refractory septic shock.

OBJECTIVE: Although the use of extracorporeal membrane oxygenation (ECMO) in shock patients is increasing worldwide, studies concerning this treatment for adult septic shock are limited. This study aimed to analyze the outcome of venoarterial ECMO in adult patients with septic shock refractory to conventional treatment. METHODS: A total of 71 consecutive patients who presented with septic shock and underwent venoarterial ECMO were reviewed. Clinical parameters were compared between survivors and nonsurvivors. Weaning and survival outcomes of these patients were compared with the control group of 253 patients who received venoarterial ECMO for cardiogenic shock. RESULTS: The mean age was 56.0 ± 12.3 years. Of the 71 septic shock patients, 11 (15.5%) were successfully weaned from ECMO after a median of 7.9 [interquartile range (IQR), 6.3-10.2] days, 5 of whom (7.0%) survived to discharge. Pre- and 6 hours post-procedural lactate levels were significantly higher in the nonsurvivors (11.6 [IQR, 7.5-15.0] vs 5.8 [IQR, 4.3-5.9], P = .036; 15.0 [IQR, 11.1-15.0] vs 5.2 [IQR, 4.7-5.4], P = .002). Rates of successful weaning from venoarterial ECMO (15.5% vs 45.5%), and of survival up to hospital discharge (7.0% vs 28.9%) were significantly lower in septic shock than in cardiogenic shock patients (n = 253; P < .001). CONCLUSIONS: Outcomes of ECMO in refractory septic shock patients were poor with a very low probability of survival. This finding raises questions concerning the utility of applying ECMO for medically refractory septic shock. Elevated arterial lactate levels pre- and post-ECMO were associated with risk of in-hospital death. Further large-scale studies are needed to validate the results of this study.

Critical Illness-Related Corticosteroid Insufficiency in Patients with Low Cardiac Output Syndrome after Cardiac Surgery.

BACKGROUND: Low cardiac output syndrome (LCOS) after cardiac surgery usually requires inotropes. In this setting, critical illness-related corticosteroid insufficiency (CIRCI) may develop. We aimed to investigate the clinical features of CIRCI in the presence of LCOS and to assess the efficacy of steroid treatment. METHODS: We reviewed 28 patients who underwent a rapid adrenocorticotropic hormone (ACTH) test due to the suspicion of CIRCI between February 2010 and September 2014. CIRCI was diagnosed by a change in serum cortisol of <9 µg/dL after the ACTH test or a random cortisol level of <10 µg/dL. RESULTS: Twenty of the 28 patients met the diagnostic criteria. The patients with CIRCI showed higher Sequential Organ Failure Assessment (SOFA) scores than those without CIRCI (16.1±2.3 vs. 11.4±3.5, p=0.001). Six of the patients with CIRCI (30%) received glucocorticoids. With an average elevation of the mean blood pressure by 22.2±8.7 mm Hg after steroid therapy, the duration of inotropic support was shorter in the steroid group than in the non-steroid group (14.1±2.3 days versus 30±22.8 days, p=0.001). Three infections (15%) developed in the non-steroid group, but this was not a significant between-group difference. CONCLUSION: CIRCI should be suspected in patients with LCOS after cardiac surgery, especially in patients with a high SOFA score. Glucocorticoid replacement therapy may be considered to reduce the use of inotropes without posing an additional risk of infection.

Influence of cannula positioning on brain injury during extracorporeal membrane oxygenation.

BACKGROUND: In veno-arterial extracorporeal membrane oxygenation (V-A ECMO), a patient is cannulated using either an atrio-aortic technique (central type ECMO; cECMO) or a femoro-femoral technique (peripheral type ECMO; pECMO). The direction of the pump flow at the aortic arch is anterograde from the ascending aorta in cECMO and retrograde from the descending aorta in pECMO. Hemodynamic differences from the position of the cannulas may influence the brain differently. To evaluate the effect of ECMO cannula positioning on the brain, hemodynamic data and plasma biomarkers were collected. METHODS: Eight pigs were randomly divided into the cECMO group (n=4) or pECMO group (n=4). ECMO was administered for 6 hours at a pump flow rate based on the mean flow of the ascending aorta. Mean arterial pressure (MAP), mean arterial flow (MAF), energy equivalent pressure (EEP), and surplus hemodynamic energy (SHE) were measured in the brachiocephalic artery every 30 minutes. During ECMO treatment, plasma was collected for analysis of interleukin-6 (IL-6), S100B, glial fibrillary acidic protein (GFAP), and neuron-specific enolase. The data were analyzed using the Mann-Whitney U tests, and repeated measures ANOVAs; significance was set at P<0.05. RESULTS: MAP and EEP at 1 and at 3 hours, MAF at all measured times, and SHE at 1 hour and 6 hours were significantly higher in the pECMO group. There was no significant difference in the levels of brain injury biomarkers between cECMO and pECMO groups. CONCLUSIONS: The hemodynamic data showed that pECMO was superior to cECMO. Based on the biomarker data, neither pECMO nor cECMO for 6 hours caused evidence of brain injury.

Effect of high- versus low-volume saline administration on acute kidney injury after cardiac surgery.

BACKGROUND: Fluid resuscitation is critical to perioperative maintenance of adequate preload and cardiac output after cardiac surgery. Liberal use of saline, however, is reportedly associated with an increased risk of acute kidney injury (AKI) in critically ill patients. This study examined the effects of high- versus low-volume saline administration on AKI after cardiac surgery. METHODS: In this retrospective study, we evaluated 1,740 consecutive patients who underwent cardiac surgery over a 2-year period. The patients were divided into high-volume saline (n=328, 18.8%) and low-volume saline (n=1,412, 81.2%) groups based on the amount of saline (>1 or ≤1 L, respectively) administered during the first 48 postoperative hours. RESULTS: AKI, the primary outcome, was defined according to the Risk, Injury, Failure, Loss, End Stage classification. There were no significant differences in the incidence of AKI (P=0.46), new renal replacement therapy (RRT) (P=0.39), and early mortality (P=0.52) between the 2 groups. Adjustment of baseline characteristics using propensity score matching showed that high-volume of saline administration was not significantly associated with an increased risk of AKI (OR, 1.22; 95% CI, 0.77-1.93; P=0.38), new RRT (OR, 1.25; 95% CI, 0.68-2.28; P=0.45), or early mortality (HR, 0.98; 95% CI, 0.48-2.02; P=0.97). These results were validated by further adjustments for significant covariates. CONCLUSIONS: High-volume administration of saline in the period following cardiac surgery was not associated with a significant increase in the risk of AKI.

Respiratory support with venovenous extracorporeal membrane oxygenation during stent placement for the palliation of critical airway obstruction: case series analysis.

BACKGROUND: Venovenous extracorporeal membrane oxygenation (VV ECMO) is used to support gas transfer of patients suffering from respiratory failure during various procedures. The purpose of this study was to evaluate the technical feasibility and safety of fluoroscopic stent placement under respiratory support with VV ECMO in patients with critical airway obstructions. METHODS: We reviewed the records of 17 patients (14 male and 3 female; mean age: 63 years; range, 30-82 years) who underwent self-expandable metallic stent (SEMS) placement under VV ECMO respiratory support for critical airway obstruction caused by malignant (n=16) or benign (n=1) etiology. RESULTS: Fluoroscopic placement of SEMS was successful in all patients (100%) with no procedure-related complications. During a mean follow-up of 83 days (range, 10-367 days), 15 (88.2%) of 17 patients showed improvement of Hugh-Jones grades (from 4.7±0.4 to 3.1±0.9, P<0.001). Removal of the endotracheal tube was possible in 11 (84.6%) of 13 patients. Weaning off ECMO was successful in all patients. The ECMO-related and stent-related complication rates were 11.7% (n=2) and 29.4% (n=5), respectively, all successfully managed by additional interventions. Indications for VV ECMO included failure of mechanical ventilation in 13 (76.5%) patients, and orthopnea in 4 (23.5%) patients. CONCLUSIONS: Fluoroscopic stent placement under VV ECMO respiratory support can be successfully performed in patients with critical airway obstruction, especially in cases of respiratory distress despite ventilation support and an inability to lie in a supine position. However, further studies will be needed to validate the standardized methods and specific indications.