Hye Ju Yeo

Low-dose heparin during extracorporeal membrane oxygenation treatment in adults

Dear Editor, Bleeding during extracorporeal membrane oxygenation (ECMO) is a potentially severe complication [1]. Excess anticoagulation may result in bleeding, unnecessary transfusions, and mortality [2]. Recent technological advances have reduced the amount of anticoagulation needed to prevent thrombosis [3]. We evaluated whether a lower target activated clotting time (ACT) during ECMO results in fewer hemorrhagic complications and a reduced need for blood products. The conventional (group C) and lower (group L) target groups comprised patients who received anticoagulation to maintain an ACT of 180–220 or 140–160 s, respectively, by continuous infusion of unfractionated heparin. Seventy-one patients were analyzed (Fig. 1 in the Electronic Supplementary Material, ESM). The indications for ECMO support were respiratory failure and cardiogenic shock (54 vs. 46 % patients, respectively). Forty-nine and 22 patients were treated with venoarterial and veno-venous ECMO, respectively; 69 % used vasopressors and 33.8 % underwent continuous renal replacement therapy. The preECMO clinical variables and coagulation profiles did not differ significantly between the two groups (Table 1 in the ESM). The mean activated partial thromboplastin time, ACT, and heparin dose during ECMO were higher in group C than L (Fig. 2 in the ESM). The incidences of major bleeding and bleeding-induced death were higher in group C than L (71.0 vs. 20.0 %, p\ 0.001; 22.6 vs. 2.5 %, p = 0.008; respectively) (Fig. 1a). The cannulation site was the most common bleeding site. The incidences of cannula-site and gastrointestinal bleeding were higher in group C than L (Table 2 in the ESM).

Impact of Implementation of an Automated Liquid Culture System on Diagnosis of Tuberculous Pleurisy.

This study was conducted to evaluate the impact of implementation of an automated liquid culture system on the diagnosis of tuberculous pleurisy in an HIV-uninfected patient population. We retrospectively compared the culture yield, time to positivity, and contamination rate of pleural effusion samples in the BACTEC Mycobacteria Growth Indicator Tube 960 (MGIT) and Ogawa media among patients with tuberculous pleurisy. Out of 104 effusion samples, 43 (41.3%) were culture positive on either the MGIT or the Ogawa media. The culture yield of MGIT was higher (40.4%, 42/104) than that of Ogawa media (18.3%, 19/104) (P<0.001). One of the samples was positive only on the Ogawa medium. The median time to positivity was faster in the MGIT (18 days, range 8-32 days) than in the Ogawa media (37 days, range 20-59 days) (P<0.001). No contamination or growth of nontuberculous mycobacterium was observed on either of the culture media. In conclusion, the automated liquid culture system could provide approximately twice as high yields and fast results in effusion culture, compared to solid media. Supplemental solid media may have a limited impact on maximizing sensitivity in effusion culture; however, further studies are required. Graphical Abstract

A Case of Clonorchiasis with Focal Intrahepatic Duct Dilatation Mimicking an Intrahepatic Cholangiocarcinoma

Biliary strictures can be caused by various diseases. Intrahepatic duct (IHD) strictures are usually related to IHD stones and cholangitis. However, focal IHD strictures without IHD stones often create diagnostic problems. Parasitic diseases such as clonorchiasis can be a rare cause of an IHD stricture. Human clonorchiasis (Clonorchis sinensis infection) is an endemic parasitic disease in Eastern Asia, including Korea, and patients acquire the infestation by eating raw fish. On radiological examinations, clonorchiasis shows typically diffuse, minimal, or mild dilatation of the small IHD, particularly in the periphery, without dilatation of the extrahepatic duct. However, diagnosis of clonorchiasis can sometimes be difficult when radiological changes are atypical. We report a case of focal left IHD dilatation caused by clonorchiasis that was confused with a malignancy.

Validity of Outcome Prediction Scoring Systems in Korean Patients with Severe Adult Respiratory Distress Syndrome Receiving Extracorporeal Membrane Oxygenation Therapy

Recently, several prognostic scoring systems for patients with severe acute respiratory distress syndrome (ARDS) requiring extracorporeal membrane oxygenation (ECMO) have been published. The aim of this study was to validate the established scoring systems for outcome prediction in Korean patients. We retrospectively reviewed the data of 50 patients on ECMO therapy in our center from 2012 to 2014. A calculation of outcome prediction scoring tools was performed and the comparison across various models was conducted. In our study, the overall hospital survival was 46% and successful weaning rate was 58%. The Predicting Death for Severe ARDS on V-V ECMO (PRESERVE) score showed good discrimination of mortality prediction for patients on ECMO with AUC of 0.80 (95% CI 0.66-0.90). The respiratory extracorporeal membrane oxygenation survival prediction (RESP) score and simplified acute physiology score (SAPS) II score also showed fair prediction ability with AUC of 0.79 (95% CI 0.65-0.89) and AUC of 0.78 (95% CI 0.64-0.88), respectively. However, the ECMOnet score failed to predict mortality with AUC of 0.51 (95% CI 0.37-0.66). When evaluating the predictive accuracy according to optimal cut-off point of each scoring system, RESP score had a best specificity of 91.3% and 66.7% of sensitivity, respectively. This study supports the clinical usefulness of the prognostic scoring tools for severe ARDS with ECMO therapy when applying to the Korean patients receiving ECMO.

Interhospital Transport System for Critically Ill Patients: Mobile Extracorporeal Membrane Oxygenation without a Ventilator

Background Extracorporeal membrane oxygenation (ECMO) has been successfully used as a method for the interhospital transportation of critically ill patients. In South Korea, a well-established ECMO interhospital transport system is lacking due to limited resources. We developed a simplified ECMO transport system without mechanical ventilation for use by public emergency medical services. Methods Eighteen patients utilized our ECMO transport system from December 2011 to September 2015. We retrospectively analyzed the indications for ECMO, the patient status during transport, and the patient outcomes. Results All transport was conducted on the ground by ambulance. The distances covered ranged from 26 to 408 km (mean, 65.9±88.1 km) and the average transport time was 56.1±57.3 minutes (range, 30 to 280 minutes). All patients were transported without adverse events. After transport, 4 patients (22.2%) underwent lung transplantation because of interstitial lung disease. Eight patients who had severe acute respiratory distress syndrome showed recovery of heart and lung function after ECMO therapy. A total of 13 patients (70.6%) were successfully taken off ECMO, and 11 patients (61.1%) survived. Conclusion Our ECMO transport system without mechanical ventilation can be considered a safe and useful method for interhospital transport and could be a good alternative option for ECMO transport in Korean hospitals with limited resources.

Awake extracorporeal membrane oxygenation in patients with severe postoperative acute respiratory distress syndrome

BACKGROUND A clinical trial of extracorporeal membrane oxygenation (ECMO) as an alternative ventilator tool is being performed as a new indication for ECMO. The purpose of this study was to evaluate the feasibility of awake ECMO to increase the success rate of weaning patients from ECMO and ventilator care during treatment of postoperative severe acute respiratory distress syndrome (ARDS). METHODS We retrospectively analyzed the clinical reports of 10 patients who underwent awake ECMO due to postoperative ARDS between August 2012 and May 2015. We analyzed patient history, the partial arterial pressure of oxygen (PaO2)/fraction of inspired oxygen (FiO2) ratio, and patient outcome. RESULTS Seven patients (70%) were weaned from ECMO without difficulty; one patient failed to maintain awake ECMO, was re-intubated after 2 days of awake ECMO, and was re-tried on awake ECMO after 4 days of ventilator care. We weaned that patient from ECMO 2 days later. We weaned a total of eight patients (80%) from awake ECMO. The ECMO duration of surviving patients was 9.13±2.2 days (range, 6-12 days), and mean ventilator use duration was 6.8±4.7 days (range, 2-16 days). Two cases failed awake ECMO and died due to disease aggravation. CONCLUSIONS Awake ECMO was a useful weaning strategy after severe postoperative ARDS, as it avoids long-duration use of mechanical ventilation. Additionally, it is possible for patients to breathe spontaneously, which might prevents respiratory muscle dystrophy.

Treatment of Pulmonary Tumor Embolism from Choriocarcinoma: Extracorporeal Membrane Oxygenation as a Bridge through Chemotherapy

A 22-year-old woman with a 1-month history of shortness of breath that was treated as a case of tuberculosis and pulmonary embolism was referred to the authors’ hospital. Because of the hemodynamic instability in this patient, venoarterial extracorporeal membrane oxygenation (ECMO) was administered in the intensive care unit. She underwent a pulmonary embolectomy for the treatment of progressive circulatory collapse secondary to a pulmonary embolism. The histopathologic result was consistent with a metastatic choriocarcinoma. Despite the surgical management, persistent refractory cardiogenic shock occurred. Subsequently, the patient was treated with chemotherapy in the presence of ECMO and responded well to chemotherapy. She was discharged after 3 months. This case suggests that metastatic choriocarcinoma should be considered as a differential diagnosis in women of childbearing age presenting with a pulmonary embolism, and ECMO may be beneficial in patients with pulmonary embolism for bridging to surgical embolectomy and chemotherapy.

Successful Single-Lung Transplantation in a Patient With a Lung Destroyed by Tuberculosis.

In most countries, patients with lungs destroyed by tuberculosis (TB) are excluded from lung transplantation (LTx) because of concerns about TB recurrence. LTx may be an effective therapeutic option for patients with chronic respiratory failure, but there are no reports of successful LTx in patients with lungs destroyed by TB. We present the case of successful single LTx in a patient with chronic respiratory failure after pneumonectomy with antituberculous chemotherapy. At the 16-month follow-up, he did not show any evidence of TB recurrence and his respiratory problems and quality of life were improved by LTx.

Current Status and Future of Lung Donation in Korea

Lung transplantation is the only effective treatment option for patients with end-stage lung disease. However, donor organ shortage makes timely transplant not possible for all patients, especially in Korea. We investigated the number and utilization of donor lungs by retrospectively reviewing all donor organs registered in the Korea Network for Organ Sharing database from March 2012 to March 2016. The donors were stratified into 4 groups by donor acceptability criteria. A total of 1,304 donors were included. Of those, 295 brain-dead donors (22.6%) consented to lung donation. Among these consented donors, 168 donors (12.9%) were retrieved for lung transplant. Retrieval rate was very low compared with that of the kidney (93.9%), liver (86.3%), and heart (27.3%). The characteristics of utilized donor lungs were: mean age, 40.5 years (range: 18 to 63 years); mean partial pressure of oxygen, 356.5 mmHg; mean smoking history, 5.9 pack-years; and mean body mass index, 22.6 kg/m2. The proportion of donors with acceptable condition of the transplanted lungs was only 39.3% (ideal 19, standard 47, marginal 70, unusable 32). Among brain-dead patients who denied to donate lungs (n = 1,009), 82 were potentially acceptable donors (ideal 19, standard 63), which was equal to half of actually transplanted lung donations. Many potential donor lungs, which are currently excluded, may be successfully used in lung transplantation in Korea. The available lung donors must be actively selected and managed to maximize the utilization of this precious resource.

Changes in the levels of beta-thromboglobulin and inflammatory mediators during extracorporeal membrane oxygenation support

Background Extracorporeal membrane oxygenation (ECMO) has been associated with platelet dysfunction, but no markers of platelet dysfunction during ECMO have been identified. Methods We investigated the potential uses of beta-thromboglobulin (beta-TG) and platelet factor 4 (PF4) as markers of platelet activation induced by ECMO in vivo. Results 13 patients who received ECMO for acute respiratory failure were included. Generalized estimating equations were used to examine the associations between days on ECMO and the plasma levels of beta-TG and PF4 and of proinflammatory markers. Analyses were performed before ECMO (baseline) and 24, 48, 72 and 168 hours after the commencement of ECMO. The plasma levels of biomolecules were measured by ELISA and Luminex assay. Percentages of platelets varied widely without statistical significance (p = 0.17). Beta-TG levels significantly decreased over the first 72 hours (p<0.001), but PF4 levels decreased nonsignificantly (p = 0.17). Inflammatory markers, that is, plasma IL-6 (p = 0.03), IL-18 (p<0.001), and MMP-8 (p<0.01) levels stabilized during an early period of ECMO support. Conclusions Our data suggest that ECMO use may not affect platelet activation during the first 3 days of ECMO. Plasma beta-TG levels may allow assessment of the time-dependent extent of ECMO-induced platelet dysfunction in patients with acute respiratory failure.