In Seok Jeong

Anticoagulation Therapy during Extracorporeal Membrane Oxygenator Support in Pediatric Patients

Extracorporeal membrane oxygenation (ECMO) is a salvage therapy for critically ill patients. Although ECMO is becoming more common, hemorrhagic and thromboembolic complications remain the major causes of death in patients undergoing ECMO treatments. These complications commence upon blood contact with artificial surfaces of the circuit, blood pump, and oxygenator system. Therefore, anticoagulation therapy is required in most cases to prevent these problems. Anticoagulation is more complicated in pediatric patients than in adults, and the foreign surface of ECMO only increases the complexity of systemic anticoagulation. In this review, we discuss the pathophysiology of coagulation, anticoagulants, and monitoring tools in pediatric patients receiving ECMO.

Traumatic rupture of the coronary sinus following blunt chest trauma: a case report

Cardiac rupture is rare but potentially life-threatening complication after chest trauma. We present the case of a 57-year-old male who developed cardiac arrest because of extensive pericardial tamponade after a falling injury. We decided to perform an exploratory sternotomy in the operating room (OR). The patient was transported to the OR on extracorporeal membrane oxygenation (ECMO) support. We found a rupture of the coronary sinus after evacuation of an extensive hematoma in the pericardium and primarily repaired the injured site. After 2 days, the patient died due to refractory cardiogenic shock. To our knowledge, this is the first reported case of rupture of the coronary sinus after blunt chest trauma.

Cardioprotective Effect of Fimasartan, a New Angiotensin Receptor Blocker, in a Porcine Model of Acute Myocardial Infarction

Cardioprotective effect of fimasartan, a new angiotensin receptor blocker (ARB), was evaluated in a porcine model of acute myocardial infarction (MI). Fifty swine were randomized to group 1 (sham, n=10), group 2 (no angiotensin-converting enzyme inhibitor [ACEI] or ARB, n=10), group 3 (perindopril 2 mg daily, n=10), group 4 (valsartan 40 mg daily, n=10), or group 5 (fimasartan 30 mg daily, n=10). Acute MI was induced by occlusion of the left anterior descending artery for 50 min. Echocardiography, single photon emission computed tomography (SPECT), and F-18 fluorodeoxyglucose cardiac positron emission tomography (PET) were performed at baseline, 1 week, and 4 weeks. Iodine-123 meta-iodobenzylguanidine (MIBG) scan was done at 6 weeks for visualization of cardiac sympathetic activity. Left ventricular function and volumes at 4 weeks were similar between the 5 groups. No difference was observed in groups 2 to 5 in SPECT perfusion defect, matched and mismatched segments between SPECT and PET at 1 week and 4 weeks. MIBG scan showed similar uptake between the 5 groups. Pathologic analysis showed similar infarct size in groups 2 to 5. Infarct size reduction was not observed with use of fimasartan as well as other ACEI and ARB in a porcine model of acute MI. Graphical Abstract

Radiodensity on serial chest X-rays for the diagnosis of foreign body aspiration in children

ObjectivesTo evaluate the utility of measuring lung radiodensity from chest X-ray for the diagnosis of foreign body aspirationMethodsRecords of 59 children with foreign body aspiration were retrospectively reviewed. Lung radiodensity and radiodensity ratio (right/left lung radio density) before and after foreign body removal were measured. Radiodensity was calculated as the relative score compared with the tenth thoracic vertebra body (100 points) and the background (0 point). The change of radiodensity ratio (difference in radiodensity ratio of the second X-ray from that of first X-ray) was compared between 22 patients (foreign body group) and 22 normal subjects (control group).ResultsIn the group of foreign body in the left bronchus, the mean (SD) radiodensity of the left lung [53.5 (12.8)] was lower than that of the right lung [60.8 (7.7), P<0.01] and it increased after foreign body removal [60.0 (6.9), P=0.02]. The radiodensity ratio decreased from 1.20 (0.30) to 0.96 (0.09) (P<0.01) after foreign body removal. In the group with a foreign body in the right bronchus, the radiodensity of the right lung [51.8 (12.8)] was lower than that of left lung [62.0 (11.7), P=0.03], and it also increased after foreign body removal [58.4 (9.6), P=0.03]. The change of radiodensity ratio in the foreign body group [15.7 (17.8)%] was higher than the control group [5.4 (4.3)%, P=0.01] and the cutoff value was 7.5%.ConclusionRadiodensity from chest X-ray could be a useful tool for diagnosing foreign body aspiration in children.

Timing in resolution of left heart dilation according to the degree of mitral regurgitation in children with ventricular septal defect after surgical closure

OBJECTIVE Children with ventricular septal defects (VSD) can have chronic volume overload, which can result in changes of left heart echocardiographic parameters. To evaluate the changes before and after surgical closure, the children were divided into three groups according to the degree of mitral regurgitation (MR), and their echocardiographic characteristics were reviewed at serial follow-up after surgical closure. METHODS The preoperative, and one-, three-, and 12-month postoperative echocardiographic data of 40 children who underwent surgical closure of VSD were retrospectively reviewed. Left ventricular end-diastolic volume (LVEDV), left ventricular end-diastolic dimension (LVEDD), left ventricular end-systolic dimension (LVESD), mitral valvular characteristics, including degree of MR and mitral valve annulus, and left atrial (LA) characteristics, including volume and dimensions, were observed. RESULTS Preoperative LVEDV, LVEDD, LVESD, mitral valvular annulus, LA volume, and LA dimensions were significantly larger in children with MR. Additionally, there were significant decreases in LVEDV, LVEDD, LA volume, and LA dimensions at one, three, and 12 months postoperatively. The degree of MR also improved to a lower grade after surgical closure of the VSD without additional mitral valve repair. CONCLUSION The echocardiographic parameters of left heart dilation and MR in children with VSD improved within the first year after surgical closure without additional mitral valve repair. Furthermore, in all of the patients with VSD, regardless of MR, LA dilation was reduced within three months after surgical closure of the VSD; however, LV and mitral valve annular dilatation decreased within 12 months.

Subsequently occurring bilateral iliopsoas hematoma: a case report

BackgroundSpontaneous bilateral iliopsoas hematomas is a rare complication after anticoagulant therapy. Furthermore, the onset of bilateral iliopsoas hematoma is unknown because the causes are unclear.Case PresentationA 65-year-old man on anticoagulant therapy after mechanical aortic valve replacement was admitted after presenting with severe pain in the left flank and abdomen. Abdominal CT revealed a large left-sided iliopsoas hematoma with extravasation. Fresh frozen plasma was transfused due to prolonged prothrombin time. Transarterial embolization was successfully performed. During the hospital stay, follow-up abdominal CT was performed and a small right-sided iliopsoas hematoma was detected. This was closely observed and an intervention was not performed, as the patient was asymptomatic. The final CT prior to discharge revealed a reduction in size of each hematoma.ConclusionsSpontaneous bilateral iliopsoas hematoma can be developed subsequently. Patients with unilateral iliopsoas hematoma should be closely monitored for development of bilateral iliopsoas hematoma.

Predictive Value of Procalcitonin for Infection and Survival in Adult Cardiogenic Shock Patients Treated with Extracorporeal Membrane Oxygenation

Procalcitonin (PCT) is a predictive marker for the occurrence of bacterial infection and the decision to terminate antibiotic treatment in critically ill patients. An unusual increase in PCT, regardless of infection, has been observed during extracorporeal membrane oxygenation (ECMO) support. We evaluated trends and the predictive value of PCT levels in adult cardiogenic shock during treatment with ECMO. We reviewed the clinical records of 38 adult cardiogenic shock patients undergoing veno-arterial ECMO support between January 2014 and December 2016. The exclusion criteria were age <18 years, pre-ECMO infection, and less than 48 hours of support. The mean patient age was 56.7±14.7 years and 12 (31.6%) patients were female. The mean duration of ECMO support was 9.0±7.6 days. The rates of successful ECMO weaning and survival to discharge were 55.3% (n=21) and 52.6% (n=20), respectively. There were 17 nosocomial infections in 16 (42.1%) patients. Peak PCT levels (mean 25.6±9.4 ng/mL) were reached within 48 hours after initiation of ECMO support and decreased to ≤5 ng/mL within one week. The change in PCT levels was not useful in predicting the occurrence of new nosocomial infections during the ECMO run. However, a PCT level >10 ng/mL during the first week of ECMO support was significantly associated with mortality (p<0.01). The change in PCT level was not useful in predicting new infection during ECMO support. However, higher PCT levels within the first week of the ECMO run are associated with significantly higher mortality.

Nosocomial Infection in Adult Patients Undergoing Veno-Arterial Extracorporeal Membrane Oxygenation

Data on the frequency of nosocomial infections during extracorporeal membrane oxygenation (ECMO) in adult populations remain scarce. We investigated the risk factors for nosocomial infections in adult patients undergoing venoarterial ECMO (VA-ECMO) support. From January 2011 to December 2015, a total of 259 patients underwent ECMO. Of these, patients aged 17 years or less and patients undergoing ECMO for less than 48 hours were excluded. Of these, 61 patients diagnosed with cardiogenic shock were evaluated. Mean patient age was 60.6 ± 14.3 years and 21 (34.4%) patients were female. The mean preoperative Sequential Organ Failure Assessment (SOFA) score was 8.6 ± 2.2. The mean duration of ECMO support was 6.8 ± 7.4 days. The rates of successful ECMO weaning and survival to discharge were 44.3% and 31.1%, respectively. There were 18 nosocomial infections in 14 (23.0%) patients. These included respiratory tract infections in 9 cases and bloodstream infections in a further 9. In multivariate analysis, independent predictors of infection during ECMO were the preoperative creatinine level (hazard ratio [HR], 2.176; 95% confidence interval [CI], 1.065–4.447; P = 0.033) and the duration of ECMO support (HR, 1.400; 95% CI, 1.081–1.815; P = 0.011). A higher preoperative creatinine level and an extended duration of ECMO support are risk factors for infection. Therefore, to avoid the development of nosocomial infections, strategies to shorten the length of ECMO support should be applied whenever possible.

Influence of Thromboxane A2 on the Regulation of Adenosine Triphosphate-Sensitive Potassium Channels in Mouse Ventricular Myocytes

Background and Objectives Adenosine triphosphate (ATP)-sensitive potassium (KATP) channels play an important role in myocardial protection. We examined the effects of thromboxane A2 on the regulation of KATP channel activity in single ventricular myocytes. Subjects and Methods Single ventricular myocytes were isolated from the hearts of adult Institute of Cancer Research (ICR) mice by enzymatic digestion. Single channel activity was recorded by excised inside-out and cell-attached patch clamp configurations at −60 mV holding potential during the perfusion of an ATP-free K-5 solution. Results In the excised inside-out patches, the thromboxane A2 analog, U46619, decreased the KATP channel activity in a dose-dependent manner; however, the thromboxane A2 receptor antagonist, SQ29548, did not significantly attenuate the inhibitory effect of U46619. In the cell-attached patches, U46619 inhibited dinitrophenol (DNP)-induced KATP channel activity in a dose-dependent manner, and SQ29548 attenuated the inhibitory effects of U46619 on DNP-induced KATP channel activity. Conclusion Thromboxane A2 may inhibit KATP channel activity, and may have a harmful effect on ischemic myocardium.

Clinical Utility of Echocardiography for the Diagnosis and Prognosis in Children with Bronchopulmonary Dsyplasia

Background Bronchopulmonary dysplasia (BPD) may result in chronic pulmonary artery hypertension and right ventricular (RV) dysfunction. Various echocardiographic assessments of RV dysfunction have been used to determine whether echocardiographic measurements of premature infants with BPD could provide sensitive measures of RV function that correlates with BPD severity. Methods Twenty-eight control subjects without BPD (non BPD group), 28 patients with mild BPD, 11 patients with moderate BPD, and six patients with severe BPD underwent echocardiograms with standard measurement such as ejection fraction by M-mode, tricuspid regurgitation pressure gradient, myocardial performance index (MPI) derived from pulse Doppler, and tissue Doppler imaging (TDI) measurements. BPD severity was classified by the NICHD/NHLBI/ORD workshop rating scale. Twenty-eight control subjects without BPD (non BPD group), 28 patients with mild BPD, 11 patients with moderate BPD, and six patients with severe BPD underwent echocardiograms with standard measurement such as ejection fraction by M-mode, tricuspid regurgitation pressure gradient, myocardial performance index (MPI) derived from pulse Doppler, and TDI measurements. BPD severity was classified by the NICHD/NHLBI/ORD workshop rating scale. Results None of the standard echocardiographic findings was significantly different between the control group and BPD groups. However, mean septal TDI-MPI of the severe BPD group (0.68 ± 0.06) was significantly (p < 0.01) higher than that of the non-BPD (0.58 ± 0.10) or the mild BPD group (0.59 ± 0.12). In addition, mean RV TDI-MPI of the severe BPD group (0.71 ± 0.13) was significantly (p < 0.05) higher than that of the non-BPD group (0.56 ± 0.08) or the mild BPD group (0.60 ± 0.125). Linear regression showed a good correlation between the severity of BPD and RV TDI-MPI (p = 0.01, R = 0.30) or septal TDI-MPI (p = 0.04, R = 0.24). Conclusion Echocardiographic evaluation of RV function based on an assessment of RV TDI-MPI can provide RV dysfunction parameter in premature infants with BPD.