Tension pneumothorax during extracorporeal membrane oxygenation

Life-threatening tension pneumothorax in neonates on extracorporeal membrane oxygenation (ECMO) has been associated with an increase in arterial oxygen tension and a decrease in peripheral perfusion, followed by a decrease in ECMO flow with progressive hemodynamic deterioration. To investigate this triad, chest tubes were placed bilaterally in 9 dogs to allow injection of air to produce tension pneumothorax. Six dogs were subsequently placed on standard venoarterial ECMO before the reinduction of tension pneumothorax. Measured values included arterial pulse pressure, inferior vena cava pressure, systemic arterial blood gases, peripheral arterial oxygen saturation, mixed venous oxygen saturation, and left heart cardiac output. Oxygen delivery was calculated from directly measured values. Each of the 6 dogs on ECMO demonstrated the triad of increased arterial oxygen tension (92 +/- 7 to 325 +/- 20 mm Hg; p less than 0.05), decreased peripheral perfusion (as evidenced by a decrease in pulse pressure from 55 +/- 4 to 31 +/- 5 mm Hg; p less than 0.05), and decreased mixed venous oxygen saturation (71% +/- 3% to 22% +/- 2% saturation; p less than 0.05) followed by a lower ECMO flow with progressive hemodynamic deterioration (oxygen delivery decreased from 285 +/- 11 to 111 +/- 12 mL/min; p less than 0.05). Aspiration of the intrathoracic air allowed return to baseline ECMO flow and hemodynamic stability in all dogs. The triad of increased arterial oxygen tension and decreased peripheral perfusion (as evidenced by a lower arterial pulse pressure and lower mixed venous oxygen saturation) followed by decreased ECMO flow with progressive hemodynamic deterioration consistently appears when tension pneumothorax occurs on ECMO.     

Establishing extracorporeal membrane oxygenation in a university clinic: case series

OBJECTIVES: Although extracorporeal membrane oxygenation (ECMO) is well established for respiratory failure in neonates, application in adults is still considered controversial. The survival of patients with acute respiratory distress syndrome and ECMO therapy is 50% to 70%. DESIGN: A retrospective analysis of 10 patients, who were placed on ECMO from September 2004 to December 2005, was performed. SETTING: University clinic. INTERVENTIONS: Venoarterial ECMO was established in 7 patients, venovenous ECMO in 2 patients, and combined venoarterial and venovenous ECMO in 1 patient. MEASUREMENTS AND MAIN RESULTS: Indications were pneumonia, acute respiratory distress syndrome, near drowning, pericardial tamponade with shock lung, right-heart failure after heart transplantation, shock lung after cardiopulmonary resuscitation, and right-heart failure in chronic thromboembolic pulmonary hypertension. Median maintenance of ECMO therapy was 56.5 hours (range, 36-240). The median Murray score was 3.3 for survivors and 4 for nonsurvivors. Overall mortality was 30%; 70% were weaned from ECMO and survived until discharge. Median pre-ECMO risk for fatal outcome according to Hemmila was 0.43 for survivors and 0.92 for nonsurvivors (p < 0.02). In 2 cases, surgical reintervention was necessary because of bleeding in one, and a side switch of the cannulae had to be performed because of femoral venous thrombosis in the other. CONCLUSIONS: ECMO has been shown to be a successful therapy for acute respiratory distress syndrome when conventional strategies have failed. Pre-ECMO risk assessment may be useful in the evaluation of patients.     

Prolonged extracorporeal support for nonneonatal respiratory failure.

Extracorporeal membrane oxygenation (ECMO) is effective for newborns with pulmonary failure unresponsive to conventional therapy. However, ECMO for the older child and adult has been controversial and not widely utilized. Over 4 years, 24 patients (aged 4 months to 16 years; 11 boys, 13 girls) underwent venoarterial ECMO (duration, 7 to 19 days) for respiratory failure. The diagnoses were: viral pneumonia (7), hydrocarbon aspiration (6), sepsis with adult respiratory distress syndrome (ARDS) (2), bacterial pneumonitis (2), tracheal stenosis (1), bilateral pulmonary contusion (1), diaphragmatic hernia with ARDS (1), ketoacidosis with ARDS (1), pulmonary artery injection of hydrocarbon (1), drowning (1), and epiglottis with barotrauma (1). Pre-ECMO blood gas ranges (and means) were PO2 18 to 65 (46), and PCO2 47 to 112 (65). Nineteen patients received dopamine, dobutamine, or other inotrope for associated cardiac and/or renal failure. Cannulation for ECMO was through neck or groin vessels in 17, and sternotomy in 7. ECMO flow rates were 150 to 250 mL/kg/min, to maintain PO2 greater than 100 and PCO2 less than 40. Nine patients (41%) survived ECMO, with eight long-term survivors, (4 hydrocarbon aspiration or injection, 1 pulmonary contusion, 1 viral pneumonia, 1 ARDS, 1 barotrauma), three of whom have mild neurological deficit. All patients with sternotomy, and 8 of 15 with neck and/or groin cannulation, required 1 to 5 explorations for hemorrhage while on ECMO. All survivors had primarily pulmonary failure; patients with combinations of pulmonary, cardiac, and renal failure did not survive. ECMO can be life-saving in the child with isolated pulmonary failure, but its efficacy in patients with multiorgan failure is uncertain.     

Prognostic determinants in extracorporeal membrane oxygenation for respiratory failure in newborns

Extracorporeal membrane oxygenation (ECMO) is becoming an accepted therapeutic modality for newborn respiratory failure, but there is little information available regarding the prognostic determinants with this technique. One hundred thirty-five newborns treated with ECMO over a 4-year period were critically analyzed with regard to the influence that birth weight, gestational age, age at initiation of ECMO, best blood gases before ECMO, number of hours on ECMO, renal failure, intracerebral hemorrhage, and long-distance air transport had on survival. Infants with meconium aspiration and those undergoing long-distance transfer showed significant differences in blood gases before ECMO, with survivors having more normal pH and carbon dioxide tension values. Intracerebral hemorrhage and renal failure that developed during ECMO were grave prognostic signs, with few survivors in either group. These data show that ability to ventilate patients before ECMO, giving normal carbon dioxide tension and pH values, is an important prognostic sign in infants with meconium aspiration and undergoing long-distance transfer for ECMO, whereas renal failure and intracerebral hemorrhage are usually lethal complications of ECMO. Each center performing ECMO should continually reevaluate this invasive technique and its results and complications.     

Application of positive end-expiratory pressure in a case with large laceration on the superior vena cava

Iatrogenic injury is a difficult situation for a surgeon. Being successful in saving a patient at risk is the major concern in this situation. Once an iatrogenic injury to the superior vena cava (SVC) is found, increasing the intrathoracic pressure is theoretically able to overcome the venous pressure and to alleviate or even stop bleeding from injury. A 76-year-old female patient, who had suffered from end-stage diabetic nephropathy, developed tension hemothorax during insertion of the cuffed hemodialysis catheter. The successful course of resuscitation without emergent operation or endovascular repair is presented here.     

Bedside exclusion of clinically significant recirculation volume during venovenous ECMO using conventional blood gas analyses

STUDY OBJECTIVE: To investigate prospectively whether blood gas samples drawn from extracorporeal membrane oxygenation (ECMO) cannulae help to exclude at least clinically significant recirculation volumes in patients with acute respiratory failure. DESIGN: Feasibility study. SETTING: Intensive care unit at a university-affiliated hospital. PATIENTS: Ten consecutive adult patients suffering from severe respiratory failure and undergoing ECMO. INTERVENTIONS: The drawing (venous) ECMO cannula was placed into the inferior vena cava via a femoral vein, and the oxygenated blood was returned via the right subclavian vein by supraclavicular access directly into the right atrium. Blood gas samples were obtained from both cannulae. MEASUREMENTS AND MAIN RESULTS: The median arterial oxygen tension (PaO(2)) obtained from the arterial cannula was 537 mmHg (range, 366 to 625 mmHg), the median mixed venous oxygen tension (PvO(2)) drawn from the venous cannula was 42 mmHg (range, 25 to 54 mmHg), which was less than 10% of that observed in the arterial cannula, and also within the physiologic range of PvO(2). The ECMO flow necessary to maintain patients' oxygen saturation above 90% (4.1 L/min; range, 1.95 to 5.8 L/min) was significantly lower than the patients' cardiac output (CO; 6.2 L/min; range, 4.1 to 7.9 L/min; p < 0.001). CONSLUSIONS; We recommend obtaining blood gas samples-immediately after initiation of ECMO-from both cannulae. A PvO(2) within physiologic range and below 10% of PaO(2) rules out any clinically relevant recirculation volume.     

Potentially lethal complications of central venous catheter placement

BACKGROUND: Placement of central venous catheters, although often considered to be a relatively safe and "junior"-level procedure, may be associated with life-threatening complications. METHODS: A recent surgical death associated with placement of a central venous catheter at this Institution led to submission of a questionnaire to pediatric surgeons referenced through the American Pediatric Surgical Association directory regarding knowledge of similar incidents and information regarding catheter placement-related complications. RESULTS: Results to this response, although anecdotal, provided data regarding complications of an acute nature, which fell into the categories of pneumothorax, hydrothorax, cardiac tamponade, and hemothorax. Of 10 children with cardiac tamponade, 7 were infants, and most complications were associated with needle stick for access, with symptoms developing within minutes up to 12 hours after the procedure. Drainage of the tamponade was performed by aspiration alone in 3 cases; surgical drainage in 6 children resulted in survival in 9 of the 10 patients. Hemothorax was described in 19 patients and appeared to be more common in children in the 1- to 6-year age group, usually associated with percutaneous access techniques. Thoracotomy for hemothorax was performed in 16 children with 11 survivors. Vascular injury to subclavian artery, vein, or superior vena caval were noted in most at operation. CONCLUSIONS: Although data included in this review are entirely anecdotal and not subject to scientific scrutiny or analysis, certain conclusions appear evident. Inherent risks of central venous catheters are intrinsic and should be discussed with the family in obtaining preoperative consent, including life-threatening risks that may necessitate urgent surgical intervention (by thoracotomy or other means). Certain technical aspects of the procedure should be rigidly followed with an experienced surgeon in attendance throughout the procedure. Rapid evaluation should be performed for any unexplained problems that occur in the operating theatre or during the early postoperative period.     

Proximal and distal cannulation of the internal jugular vein for ECMO in a primate.

Extracorporeal membrane oxygenation (ECMO) is lifesaving for infants with severe respiratory distress but is complicated by severe intracranial hemorrhage in 10% to 30% of patients. Intracranial venous hypertension, as a result of ligation of the internal jugular vein (IJV), has been hypothesized as a contributing factor to cerebral edema and subsequent hemorrhage. Accessory cephalad IJV cannulation may serve as a means of additional venous drainage to the pump as well as protection against intracranial venous hypertension. Proximal and distal cannulation of the IJV were studied in a primate model. The parameters monitored included sagittal sinus, right and left ventricular pressures as well as venous pressure in the ECMO circuit. The cephalad venous cannula was clamped and unclamped at 30-minute intervals. There was no significant difference in sagittal sinus or intracranial pressures during periods of cephalad cannula clamping or unclamping. Venous return was augmented when the cephalad cannula was unclamped. Cephalad cannulation has no demonstrable protective effect on intracranial, subarachnoid or venous pressures but does improve venous return to the ECMO circuit. It is concluded that cephalad venous cannulation is not necessary in all cases and should be reserved for those patients requiring additional venous drainage to support pump flow.     

Injuries and liability related to central vascular catheters: a closed claims analysis

BACKGROUND: To assess changing patterns of injury and liability associated with central venous or pulmonary artery catheters, the authors analyzed closed malpractice claims for central catheter injuries in the American Society of Anesthesiologists Closed Claims database. METHODS: All claims for which a central catheter (i.e., central venous or pulmonary artery catheter) was the primary damaging event for the injury were compared with the rest of the claims in the database. Central catheter complications were defined as being related to vascular access or catheter use or maintenance. Statistical analysis was performed using the chi-square test, Fisher exact test, or Z test (proportions) and the Kolmogorov-Smirnov test (payments). RESULTS: The database included 110 claims for injuries related to central catheters (1.7% of 6,449 claims). Claims for central catheter injuries had a higher severity of injury, with an increased proportion of death (47%) compared with other claims in the database (29%, P < 0.01). The most common complications were wire/catheter embolus (n = 20), cardiac tamponade (n = 16), carotid artery puncture/cannulation (n =16), hemothorax (n =15), and pneumothorax (n =14). Cardiac tamponade, hemothorax, and pulmonary artery rupture had a higher proportion of death (P < 0.05) compared with the rest of the central catheter injures. The proportion of claims for vascular access injury increased (47% to 84%) and use/maintenance injury decreased (53% to 16%) in 1994-1999 compared with 1978-1983 (P < 0.05). CONCLUSIONS: Claims related to central catheters had a high severity of patient injury. The most common complications causing injury were wire/catheter embolus, cardiac tamponade, carotid artery puncture/cannulation, hemothorax, and pneumothorax.     

Extracorporeal Membrane Oxygenation as Bridge to Lung Transplantation

Lung transplantation (OLT) is a viable option for end-stage pulmonary diseases in selected patients with satisfactory long-term results. However, the paucity of available donors engenders a prolonged stay on the waiting list with progressive decline of lung function. In cases of sudden respiratory failure, admission to an intensive care unit with institution of extracorporeal membrane oxygenation (ECMO) may be an option while a waiting an emergency OLT. In 12 OLT candidates we started ECMO because of acute decline of lung function. Eleven patients had cystic fibrosis and the other subject, histiocytosis X. In 7 patients bilateral OLT was performed after a mean waiting time of 6 days from ECMO institution; 5 patients died on ECMO at a mean time of 11.6 days. After OLT 2 patients required reoperation for hemothorax; renal failure and acute leg ischemia occurred in 2 patients. The mean weaning time from ECMO after OLT was 2.14 days. No patient died in the perioperative period and 1-year survival was 85.7%. ECMO represents a valid option as a bridge to urgent OLT for selected candidates.     

Neonatal diaphragmatic hernia. An improving outlook with extracorporeal membrane oxygenation

In a 15-year period, 89 newborns were treated for congenital diaphragmatic hernia. The patients were divided into three groups, depending on postoperative therapeutic support available: group 1, ventilator therapy only; group 2, ventilator therapy plus pulmonary vasodilators (tolazoline hydrochloride); and group 3, ventilators, tolazoline, and/or extracorporeal membrane oxygenation (ECMO). The three groups were identical for presenting symptoms, signs, and preoperative blood gas determinations. The survival for each group was as follows: group 1, 17 (40%) of 42; group 2, 14 (45%) of 31; and group 3, 12 (75%) of 16. Complications requiring further operations were identical. All survivors in groups 1 and 2 are normal developmentally, while one of five group 3 ECMO survivors has developmental delay and another has long-term ventilator dependence. These data suggest that ECMO, an invasive technique for newborn respiratory failure, improves survival in congenital diaphragmatic hernia.     

Thoraxtrauma

Chest injuries can be sustained in isolation or in association with multiple injuries. Life-threatening complications may ensue because organs that are vital to survival of the organism are situated within the thoracic cavity. These complications include airway obstruction, tension pneumothorax, wide open pneumothorax, flail chest, cardiac tamponade and massive hemothorax. The mortality of patients hospitalized with chest injury can be as high as 10%. Clinical examination and awareness of the possibility of other injuries (high level of suspicion) are essential, and standard chest X-ray, ultrasound and thoracic computed tomography may also be needed for the diagnosis. The first part of this serial paper on the management of chest injuries focuses on anatomical aspects, pathophysiology and symptoms, but mainly on the indications for the standard diagnostic procedures and further high-tech examinations.     

Cephalic jugular venous blood gas measurement during neonatal venoarterial extracorporeal membrane oxygenation

Cannulation of the cephalic portion of the right internal jugular vein during extracorporeal membrane oxygenation (ECMO) allows for increased venous return flow to the circuit. This procedure also allows access to venous drainage from the brain. We reviewed data from simultaneous blood gases obtained from the cephalic jugular vein and the mixed venous return in 5 neonates during venoarterial ECMO. Cephalic venous pO 2 values were significantly lower than mixed venous pO 2 values (P less than .001). The values for pH and pCO 2 did not vary between the sites. Our experience with 34 infants using cephalic jugular drainage is reviewed. Since the institution of right jugular venous drainage, the intracranial hemorrhage rate in neonates undergoing ECMO at our center has decreased from 34% to 6% (p less than .01).     

Chest injury. Part I: Significance--symptoms--diagnostic procedures

Chest injuries can be sustained in isolation or in association with multiple injuries. Life-threatening complications may ensue because organs that are vital to survival of the organism are situated within the thoracic cavity. These complications include airway obstruction, tension pneumothorax, wide open pneumothorax, flail chest, cardiac tamponade and massive hemothorax. The mortality of patients hospitalized with chest injury can be as high as 10%. Clinical examination and awareness of the possibility of other injuries (high level of suspicion) are essential, and standard chest X-ray, ultrasound and thoracic computed tomography may also be needed for the diagnosis. The first part of this serial paper on the management of chest injuries focuses on anatomical aspects, pathophysiology and symptoms, but mainly on the indications for the standard diagnostic procedures and further high-tech examinations.     

Venovenous perfusion in ECMO for newborn respiratory insufficiency. A clinical comparison with venoarterial perfusion.

Venoarterial (VA) extracorporeal membrane oxygenation (ECMO) has been successful in the treatment of newborns less than 1 week of age and greater than 2000 gm birthweight with respiratory failure resistant to current medical and surgical management. While VA ECMO supports the heart as well as the lungs, it has the disadvantage of requiring carotid artery ligation and the possibility of perfusing air bubbles or particles into the arterial tree. We have treated 11 newborns with respiratory failure with venovenous (VV) ECMO returning the oxygenated blood to a cannula in the distal iliac vein. We compared these patients with 16 patients treated during the same period of time with VA ECMO. Three of the 11 VV patients required conversion to VA ECMO because of inadequate oxygenation and unstable hemodynamic situations. Ten of the 11 VV patients survived. Eleven of the 16 VA patients survived. The better survival in these patients treated with VV ECMO is attributed to their more favorable initial condition compared to patients treated with VA ECMO. The disadvantages of VV ECMO include a longer operative time to place the cannulas, groin wound problems, and persistent leg swelling along with the necessity to convert some patients to VA ECMO. Although this experience demonstrates that newborns with severe respiratory failure can be supported with VV ECMO, the complications and lack of practical advantages over VA lead us to recommend VA ECMO for routine clinical use at present.     

Massive systemic air embolism during extracorporeal membrane oxygenation support of a neonate with acute respiratory distress syndrome after cardiac surgery

Extracorporeal membrane oxygenation (ECMO) is universally accepted as a potential lifesaving therapy for neonates suffering severe cardiorespiratory failure, with survival reported as 81% weaning off ECMO and 69% to hospital discharge in this population. Although ECMO may reduce mortality in certain neonatal patients, it is associated with significant complications. Air in the circuit complicates 4.9% of neonatal ECMO runs, and it is crucial that all ECMO caregivers are trained in the prevention of air embolism and possess the knowledge necessary to efficiently identify and remove air from the ECMO circuit to prevent life threatening consequences. We present a fatal case of neonatal systemic air embolism leading to massive entrainment of air into the ECMO venous return cannula of a neonatal patient with acute respiratory distress syndrome following repair of obstructed total anomalous pulmonary venous connection. We describe the pathophysiology and presentation of this rare condition and the importance of early recognition, due to its high mortality rate.     

Venovenous extracorporeal membrane oxygenation support for treatment of bilateral spontaneous pneumothorax

Bilateral spontaneous pneumothorax is a rare but serious cause of respiratory distress. We treated a 77-year-old male with severe hypoxia caused by bilateral spontaneous pneumothorax using video-assisted thoracoscopic bullectomy assisted by a venovenous extracorporeal membrane oxygenation (ECMO) device. The patient came to the emergency department of our hospital with complaints of cough and dyspnea, and was hospitalized with right-side spontaneous pneumothorax and left-side pneumonia. After 12 days, a chest radiograph was performed to investigate persistent progressive shortness of breath at rest, which demonstrated contralateral pneumothorax. A chest tube was inserted into the left pleural cavity, and surgery was performed for bilateral pneumothorax by video-assisted thoracoscopic surgery (VATS) assisted by venovenous ECMO. Gas exchange was satisfactory throughout the surgical procedure and the postoperative course was uneventful without complications. Venovenous ECMO was effective for facilitation of VATS and reduced the risk of an intra-operative hypoxic condition.     

Application of extracorporeal membrane oxygenation in adult burn patients

Adult respiratory distress syndrome (ARDS) has been the major cause of mortality in burn injury. The authors reported the experience of using extracorporeal membrane oxygenation (ECMO) to treat adult burn patient with ARDS. Three patients with burn or electric injury, around 48.9% of body surface area over second-degree burns, developed ARDS after resuscitation. All had positive blood culture and depended on a ventilator more than 5 days before ECMO. Venovenous (VV) ECMO was started at the beginning of severe respiratory failure with an oxygen index of 61.6 +/- 15.5 cm H2O/mm Hg (> or =40 cm H2O/mm Hg), partial arterial oxygen tension to inspired oxygen fraction (Pa(O2)/Fi(O2)) of 46.1 +/- 7.0 mm Hg (< or =200 mm Hg), positive end expiratory pressure (PEEP) of 15.7 +/- 1.6 cm H2O (> or =10 cm H2O), alveolar-arterial difference in oxygen concentration (A-a D(O2)) of 618.9 +/- 19.3 mm Hg (> or =300 mm Hg), and lung compliance of 17.3 +/- 4.6 ml/cm H2O (< or =30 ml/cm H2O). The VV type had to be converted to the newly designed veno-venoarterial (V-VA) ECMO due to the myocardial dysfunction. Two of three patients survived. The duration of ECMO was 160.2 +/- 51.1 h. Two patients received debridement of escar during ECMO support and desmopressin infusion, and no increased bleeding or coagulopathy was found. The respiratory parameters were significantly improved after ECMO, especially in the survivors. ECMO is also suitable for ARDS in adult burn injury.     

The multiply injured patient

The multiply injured patient with significant thoracic and extra-thoracic injuries poses a number of challenges. Pericardial tamponade, tension pneumothorax and massive hemothorax can and should be diagnosed clinically. In more stable patients, chest computed tomography (CT) scan is an excellent screening test. The concept of damage control resuscitation and damage control surgery have shown promise in patients with multiple, critical injuries. Beta-blockade of patients with blunt thoracic aortic injuries can be used as a temporizing damage control measure when the risks of operation or intervention are very high (traumatic brain injury, severe right or bilateral pulmonary contusion, unstable pelvic fractures). Patients with multiple penetrating wounds require the surgical team to be expeditious and flexible, and damage control is a helpful strategy in these patients.     

Spontaneous hemothorax in patients with von Recklinghausen’s disease

Spontaneous massive intrathoracic bleeding is rare except for the rupture of aortic aneurysm or pleural adhesions in association with pneumothorax. We encountered two cases of critical massive hemothorax in patients with von Recklinghausen's disease (type I neurofibromatosis). Case 1; a 59-year-old female suddenly experienced severe back pain followed by syncope and shock. The hemothorax was caused by a bleeding of diffuse type neurofibroma of the parietal pleura and she underwent thoracotomy and surgical ligation of the bleeding vessels. Case 2; a 46-year-old male suddenly suffered back pain and fainted while driving. An intercostal aneurysmal rupture caused a spontaneous hemothorax and he underwent chest tube drainage followed by endovascular coil embolization. We reviewed 23 cases reported in the literature, including our two cases. Spontaneous hemothorax in patients with von Recklinghausen's disease is a life-threatening syndrome and may require emergency surgical or endovascular embolization.