The intersection of bronchoscopy and extracorporeal membrane oxygenation

Central airway obstruction (CAO), which results from malignant, benign or iatrogenic etiologies, causes significant morbidity and mortality and can be seen in both the pediatric and adult patient population. Patients frequently present to the hospital with dyspnea, stridor, and respiratory distress, indicating impending respiratory failure. Heliox is used to help alleviate symptoms while procedural planning takes place. A multidisciplinary approach to airway management is often needed. Interventional pulmonologists treat CAO with rigid of flexible bronchoscopy in order to deliver therapeutic interventions under general anesthesia. In severe CAO where there is concern for total loss of the airway creating a life-threatening situation for the patient during procedural intervention, short term extracorporeal membrane oxygenation or ECMO has been successfully reported in the literature to provide ventilation and oxygenation support throughout the procedure. Venoarterial ECMO can be used to augment cardiac output in cases of central tumors with cardiac involvement. ECMO can also be used for the removal of tracheal stents when there is a concern that ventilation will be interrupted for a prolonged period of time. ECMO has also been reported as a salvage measure for patients with life threatening hemoptysis until more definitive interventions can be performed. Short term ECMO cannulation can be used with limited associated morbidity and a heparin-free approach can be pursued when there is a concern for bleeding. We will briefly review the anesthetic considerations in CAO as well as review cases of CAO where ECMO was employed to safely alleviate the airway compromise.     

Flexible bronchoscopic excision of a tracheal mass under extracorporeal membrane oxygenation

Tracheal tumor is a rare but life-threatening condition that can cause obstruction of the airway. Management of tracheal tumors is very challenging and includes surgical resection, radiotherapy, and therapeutic bronchoscopy. Herein, we present a very rare case of an 88-year-old female patient with a tracheal mass due to direct invasion of a mediastinal teratoma. We devised a new method for resection of the tracheal mass because management of her airway and the tracheal mass by conventional methods was impossible. We successfully resected the tracheal mass with flexible bronchoscopic electrocautery under extracorporeal membrane oxygenation (ECMO) without any complications. When management of a patient’s airway and tracheal mass are impossible by conventional methods, this technique may be very useful.     

经皮穿刺静脉-静脉体外膜肺的动物实验研究

目的在犬急性肺损伤的动物模型上探讨经皮穿刺静脉-静脉体外膜肺(V-VECMO)支持的效果。方法6只雄性犬利用油酸(0.1ml/kg)建立急性肺损伤模型。经皮穿刺右颈内静脉和右股静脉放置插管(分别是17Fr、10Fr),接ECMO管道灌注流量35～40ml/kg/min,氧气流量1～1.5L/min。ECMO前2h与呼吸机并用,呼吸机参数为SIMV模式,FiO20.5,TV5～6ml/kg,RR20次/分;后2h停止呼吸机的使用。记录注射油酸前、肺损伤出现后ECMO前、ECMO2h、ECMO4h的动脉血气值变化。结果注射油酸后4～6h,在纯氧高通气状态下犬动脉氧分压为106±15mmHg。ECMO2h动脉氧分压为98±7mmHg氧饱和度95.5±2.2%;ECMO4h动脉氧分压为67±3mmHg,氧饱和度为92.3±2.2%。ECMO过程中二氧化碳分压低于注射油酸前水平(p<0.05)。结论经皮穿刺V-VECMO可以帮助机体排出二氧化碳,吸收氧气,降低急性肺损伤的机械通气模式。     

Congenital tuberculosis requiring extracorporeal membrane oxygenation

We describe a 6-week-old infant with congenital tuberculosis with cardiorespiratory failure. She was successfully treated with ECMO initiated after worsening hypoxemia despite mechanical ventilation.     

Examination of hyperlucent foci and clinical outcomes in pediatric cardiac patients on extracorporeal membrane oxygenation

Background: A number of cardiac patients on venoarterial extracorporeal membrane oxygenation (VA‐ECMO) at our institution were found to have hyperlucent foci evident on echocardiography. However, the clinical significance of these findings is not known. Methods: To investigate this phenomenon further we undertook a retrospective analysis to determine the prevalence and clinical implications of hyperlucent foci in children supported with VA‐ECMO. Results: From January 2002 to September 2009 49 subjects were supported with VA‐ECMO. Of these, 12 (24%) were found to have hyperlucent foci. Foci were multifocal in six subjects (50%) and the most common location was left ventricular wall. No association was noted between primary cardiac diagnoses, or for inciting reason for placement on ECMO (extracorporeal cardiopulmonary resuscitation vs. transition from cardiopulmonary bypass to ECMO). There was no association between the presence of the foci and death in less than 14 days following decannulation from ECMO, hospital survival 42% versus 43%, P = 0.1. Among subjects who survived at least 14 days after ECMO decannulation hyperlucent foci resolved in 5 of 7. Conclusions: Hyperlucent foci can be seen in children supported by VA‐ECMO. They do not portend a poorer prognosis. Among hospital survivors resolution is the norm. (Echocardiography 2011;28:358‐362)     

A case report of acquired methemoglobinemia rescued by veno-venous extracorporeal membrane oxygenation

Rationale:Severe methemoglobinemia (Met-Hb) is rare. The delayed diagnosis and treatment often cause further damage. The management of cellular hypoxemia is challenging and the use of extra-corporeal membrane oxygenation (ECMO) has never been reported.Patient concerns:The young patient, healthy with unremarkable past medical history, was sent to emergency room with out-of-hospital circulatory arrest (OHCA) and severe generalized cyanosis. His family reported he ingested sodium nitrite accidentally.Diagnoses:After successful resuscitation and return of spontaneous circulation (ROSC), the paradoxically normal arterial blood gas (ABG) with the unusual brownish blood led to the suspicion of Met-Hb. The lab test confirmed it and showed a very high level of 80%.Interventions:Because of recovered and normal cardiac function, we placed veno-venous extracorporeal membrane oxygenation (VV-ECMO) for tissue hypoxemia in addition to exchange transfusion, vitamin C, and methylene blue.Outcomes:Met-Hb blood level dropped rapidly. After vigorous rehabilitation for weeks, the patient was able to be discharged home without major neurological sequela.Lessons:VV-ECMO can hyper-oxygenate the hypoxemic tissue regardless the etiology and minimize hypoxemia-reperfusion injury while awaiting the definite diagnosis and therapy.     

Use of extracorporeal membrane oxygenation in cystic fibrosis in an Australian cystic fibrosis centre

Extracorporeal membrane oxygenation (ECMO) support is used in selected patients with cystic fibrosis (CF) as a bridge to transplantation. Our aim was to describe briefly treatment and outcomes of six CF patients who received ECMO. One patient received a lung transplant and another recovered from acute respiratory failure. Four died despite ECMO support. Lack of timely availability of suitable donor lungs and patient selection are contributing factors.     

Blade and balloon atrial septostomy for left heart decompression in patients with severe ventricular dysfunction on extracorporeal membrane oxygenation

Extracorporeal membrane oxygenation (ECMO) is used as circulatory support or bridge to transplantation in patients with severe left ventricular (LV) dysfunction. Left heart decompression is needed to reduce pulmonary edema, prevent pulmonary hemorrhage, and reduce ventricular distention that may aid in recovery of function. We reviewed our experience from November 1993 to December 1997 with 10 patients having severe LV dysfunction (7 myocarditis, 3 dilated cardiomyopathy) who required circulatory support with ECMO and who underwent left heart decompression with blade and balloon atrial septostomy (BBAS). Patients ranged in age from 1 to 24 years (median, 3 years). Indications for BBAS included left atrial/left ventricular distension (10), pulmonary edema/hemorrhage (9), or severe mitral regurgitation (2). BBAS was performed electively in eight patients and urgently in two patients. BBAS was performed while on ECMO in seven patients and pre-ECMO in three. A femoral venous approach was used in all patients. ECMO patients were fully heparinized. Transseptal puncture was required in nine patients while one patient had a patent foramen ovale. Blade septostomy was performed in all patients. Enlargement of the defect was then performed by stationary balloon dilation in nine and Rashkind balloon atrial septostomy in one. Balloon diameters ranged from 10 to 20 mm. Sequential balloon inflations were performed in some patients. Adequacy of the atrial septal defect (ASD) was confirmed by pressure measurement and echocardiography. Adequate left heart decompression was achieved in all patients. Pulmonary edema improved in nine of nine patients. Left atrial mean pressure fell from a mean of 30.5 mm Hg, (range, 12–50 mm Hg) to 16 mm Hg (range, 9–24 mm Hg). Left atrial to right atrial pressure gradient fell from a mean of 20 mm Hg pre-BBAS to 3 mm Hg post-BBAS. ASDs ranged in size from 2.5 to 8 mm (mean, 5.9 mm). Complications included needle perforation of the left atrium without hemodynamic compromise (one), ventricular fibrillation requiring defibrillation (one), and hypotension following BBAS which responded to volume infusion (two). Duration of ECMO ranged from 41 hr to 704 hr (mean, 294 hr). Seven patients survived and four patients had recovery of normal LV function. Of those who recovered, two had no ASD at follow-up while two ASDs are patent 14 days and 3 months post-BBAS. Three patients underwent successful cardiac transplantation. Three patients died, all of whom had multisystem organ failure with or without sepsis. A patent ASD was noted at transplant (three) or autopsy (two). No patient required a second BBAS. BBAS alleviates severe left atrial hypertension and pulmonary edema. In addition, BBAS avoids the potential bleeding complications of surgical left heart decompression. Stationary balloon dilation of the atrial septum is an effective alternative to Rashkind balloon septostomy in older patients. BBAS achieves left heart decompression that may permit recovery of LV function or allow extended ECMO support as a bridge to transplant. Cathet. Cardiovasc. Intervent. 46:179–186, 1999. © 1999 Wiley-Liss, Inc.     

体外膜肺氧合治疗心脏手术后急性心功能衰竭的疗效

目的总结体外膜肺氧合(extracorporeal membrane oxygenation,ECMO)治疗心脏外科术后出现严重心功能衰竭的应用经验。方法选择自2009年10月至2013年2月在中山市人民医院进行心脏外科手术,且术后出现急性心功能衰竭而应用ECMO治疗的22例患者为研究对象,总结其应用ECMO治疗的临床情况。结果上机维持时间为(100.0±89.2)h。因心脏功能无法恢复,无法撤机并死亡4例;成功撤机18例,其中4例顺利撤机,但仍最终死亡;顺利恢复并出院14例。辅助过程中主要并发症为出血和感染。结论 ECMO的应用有利于辅助心肺功能和防治并发症,对于心脏术后心功能衰竭的治疗疗效肯定。     

Alveolar and serum concentrations of imipenem in two lung transplant recipients supported with extracorporeal membrane oxygenation

Venovenous extracorporeal membrane oxygenation (ECMO) is increasingly used in patients with respiratory failure who fail conventional treatment. Postoperative pneumonia is the most common infection after lung transplantation (40%). Imipenem is frequently used for empirical treatment of nosocomial pneumonia in the intensive care unit. Nevertheless, few data are available on the impact of ECMO on pharmacokinetics, and no data on imipenem dosing during ECMO. Currently, no guidelines exist for antibiotic dosing during ECMO support. We report the cases of 2 patients supported with venovenous ECMO for refractory acute respiratory distress syndrome following single lung transplantation for pulmonary fibrosis, treated empirically with 1 g of imipenem intravenously every 6 h. Enterobacter cloacae was isolated from the respiratory sample of Patient 1 and Klebsiella pneumoniae was isolated from the respiratory sample of Patient 2. Minimum inhibitory concentrations of the 2 isolated strains were 0.125 and 0.25 mg/L, respectively. Both patients were still alive on day 28. This is the first report, to our knowledge, of imipenem concentrations in lung transplantation patients supported with ECMO. This study confirms high variability in imipenem trough concentrations in patients on ECMO and with preserved renal function. An elevated dosing regimen (4 g/24 h) is more likely to optimize drug exposure, and therapeutic drug monitoring is recommended, where available. Population pharmacokinetic studies are indicated to develop evidence‐based dosing guidelines for ECMO patients.     

Spontaneous echo contrast mimicking aortic root thrombus in a patient supported with extracorporeal membrane oxygenation

Aortic root spontaneous echo contrast is a rare but significant finding. We report a 31‐year‐old female who was placed on venoarterial extracorporeal membrane oxygenation emergently for acute mitral regurgitation secondary to papillary muscle rupture. Following stabilization, subsequent transesophageal echocardiography suggested aortic root thrombus and prompted emergent surgery. However, further inspection with intraoperative transesophageal echocardiography revealed a spontaneous echo contrast which aided us in the intraoperative decision making.     

Bedside transseptal balloon dilation atrial septostomy for decompression of the left heart during extracorporeal membrane oxygenation

A 10-year-old male presented with severe heart failure secondary to myocarditis. Venoarterial extracorporeal membrane oxygenation was instituted. He developed severe left heart distention with acute pulmonary hemorrhage. Balloon dilation of the atrial septum to decompress the left atrium was performed at the bedside with transesophageal echocardiographic guidance. Cathet. Cardiovasc. Intervent. 46:197–199, 1999. © 1999 Wiley-Liss, Inc.     

应用体外膜肺氧合技术治疗胎粪吸入综合征一例及文献复习

目的探讨应用体外膜肺氧合技术（extracorporeal membrane oxygenation,ECMO）救治重症新生儿胎粪吸入综合征的治疗方法。方法报告1例应用ECMO救治重症新生儿胎粪吸入综合征的过程,并进行文献复习。结果患儿病情危重,经使用肺表面活性物质、高频振荡辅助通气及一氧化氮吸入等治疗后效果欠佳,后予ECMO治疗有效。最终治愈出院。结论对于危重症胎粪吸入综合征患儿可适当放宽ECMO治疗指征,及早予ECMO治疗。但需注意术中及术后感染、神经系统损害等相关并发症。     

Case report: atrial septostomy as a bridge to lung transplantation in a patient with venovenous extracorporeal membrane oxygenation

Introduction:Advances in critical care management have led to the recent increase in the use of extracorporeal membrane oxygenation (ECMO) as a bridge to lung transplantation (LT). Patients with respiratory failure requiring venovenous ECMO usually experience progressive right ventricular (RV) failure. Diagnosis and treatment of RV failure during ECMO are essential for improving the prognosis of patients.Patient concerns:A 28-year-old female patient underwent allogeneic hematopoietic stem cell transplantation (HSCT) from a matched unrelated donor for acute myeloid leukemia presenting with progressive dyspnea.Diagnoses:Computed tomography revealed multifocal patchy peribronchial and subpleural ground-glass opacities in both lungs, and the patient was clinically diagnosed with cryptogenic organizing pneumonia.Interventions and outcomes:Despite intensifying systemic corticosteroid therapy, her symptoms deteriorated, and mechanical ventilation and ECMO were applied. During treatment, her respiratory failure continued to progress, and systemic hypotension developed. An echocardiogram showed evidence of RV failure, and percutaneous atrial septostomy was performed for RV decompression. After a balloon atrial septostomy was performed, RV failure of the patient improved, and LT was successfully performed.Lessons:We report the first case of atrial septostomy as a successful bridge to LT in a HSCT recipient with venovenous ECMO. Atrial septostomy could be an option for management of RV failure during ECMO. Further studies need to be conducted to validate the effect of atrial septostomy in patients with RV failure during ECMO.     

Massive hollow catheter thrombus in venovenous extracorporeal membrane oxygenation assisted lung transplantation: A case report

Rationale:Catheter-related thrombosis is a serious complication of lung transplantation under venovenous extracorporeal membrane oxygenation (ECMO). Although ECMO-related thrombosis is not uncommon, there are few reports of giant hollow catheter thrombosis in lung transplantation under venovenous ECMO (ECMO). Blood loss and transfusion of coagulation factors may promote ECMO-related thrombosis. Hollow catheter thrombus was not detected on ultrasonography performed after initiation of ECMO. Therefore, it is essential to identify, manage, and reduce or avoid such thrombosis.Patient concerns:We report a rare case of a 43-year-old man with advanced silicosis who developed a massive hollow catheter thrombus during lung transplantation. Anticoagulant therapy did not affect the size of the thrombus.Diagnosis:Giant hollow catheter thrombosis was diagnosed by ultrasonography. Thrombosis from the right external iliac vein to the inferior vena cava was found in the shape of the ECMO pipe.Interventions:Heparin was prescribed as an anticoagulant.Outcomes:Anticoagulant therapy did not affect the size of the thrombus during 2 weeks. The patient developed an infection and died of multiple organ failure.Conclusion:It is uncommon for massive hollow thrombus to occur during venovenous-ECMO-assisted lung transplantation. Fibrinogen and prothrombin complexes promote the formation of thrombus, and the measurement of the wall thickness of ECMO catheter may help to detect such thrombus.     

A case report of gadopentetate dimeglumine-induced cardiac arrest: Resuscitation using extracorporeal membrane oxygenation

Gadopentetate dimeglumine (Gd-DTPA) is commonly used for enhancement in magnetic resonance imaging, but rarely causes serious adverse reactions. The patient presented in this report had a cardiac arrest and multiple organ dysfunction syndrome within a short time after administration of Gd-DTPA. Immediately after receiving an intravenous injection of Gd-DTPA, the patient felt nausea and chest tightness, and developed systemic erythema. He was successfully treated using veno-arterial extracorporeal membrane oxygenation (ECMO) combined with continuous renal replacement therapy without any serious complications or neurological deficits. We report a patient who was successfully treated for Gd-DTPA-induced cardiac arrest with ECMO. Thus, ECMO may be an effective treatment for cardiac arrest secondary to anaphylaxis.