Penetrating thoracic injury requiring emergency pneumonectomy supported with two ECMO runs: A testament to multidisciplinary critical care medicine

Post-traumatic pneumonectomies are uncommon and, if necessary, carry significant mortality. The use of extracorporeal membrane oxygenation (ECMO) for lung injury in trauma patient has demonstrated efficacy with minimal bleeding complications. We report a case of a young man with a penetrating thoracic injury that required a pneumonectomy supported with two separate ECMO runs for pulmonary failure postoperatively.

Early enteral feedings in adults receiving venovenous extracorporeal membrane oxygenation

INTRODUCTION

For over 20 years extracorporeal membrane oxygenation (ECMO) has been an advanced treatment for adults, children and neonates with severe respiratory failure that has failed to respond or improve with conventional therapy. Withholding enteral feeding in patients on ECMO is common practice in many centers, based partly on the risk of splanchnic ischemia resulting in loss of intestinal integrity, predisposing to bacterial translocation and sepsis. We report one center's experience with early enteral nutrition in adult patients receiving venovenous (VV) ECMO for severe respiratory failure.

METHODS

Adult patients that received VV ECMO at LSUHSC-Shreveport over the last 8 years were eligible for inclusion.

RESULTS

A total of 27 patients met these criteria and their charts and nutrition therapy reviewed. Average duration of ECMO support was 8.7 +/- 3.6 days. Twenty-six of 27 (96%) received enteral nutrition via gastric tube alone or in combination with total parenteral nutrition (TPN). Eighteen patients received enteral nutrition as their only source of nutritional supplementation, with the remainder receiving partial nutrition support via the parenteral route. Seventy-five percent of the patients received prokinetic medication within the first 24 hours, with 95% receiving prokinetic therapy by 48 hours. No patients developed intestinal ischemia, gastrointestinal bleeding, or other complications related to early enteral feeding.

CONCLUSION

Enteral nutrition started within the first 24 to 36 hours of initiating venovenous ECMO support is safe and well-tolerated in adults. No serious adverse events were attributable to enteral nutrition in these patients.

Heparin-induced thrombocytopenia in a pediatric patient receiving extracorporeal membrane oxygenation managed with argatroban

INTRODUCTION

Heparin-induced thrombocytopenia (HIT) is rare in the pediatric population, with a majority occurring in the pediatric intensive care unit setting. All cases reported to date have been associated with the use of unfractionated heparin. Because unfractionated heparin is the anticoagulant of choice for extracorporeal membrane oxygenation (ECMO) and other extracorporeal therapies, the development of HIT in these patients can be devastating, making management problematic. We report a case of HIT type II with evidence of small-vessel arterial thrombosis in a 17-month-old boy receiving ECMO and continuous renal replacement therapy successfully treated with argatroban.

CASE

The patient was a 17-month-old boy with severe hypercapnic and hypoxemic respiratory failure secondary to asthma and mucus plugging that failed conventional and unconventional ventilation. Venovenous ECMO was initiated, and within 24 hrs, there was a precipitous decrease in the platelet count, with the development of cutaneous ischemia involving his lower limbs. Argatroban was started and the child maintained on ECMO and continuous renal replacement therapy, with resolution of the cutaneous ischemia and recovery of the platelet count. Heparin-associated antibodies were positive.

DISCUSSION

HIT is rare in the pediatric population. Recognition of HIT is vital because withdrawal of heparin is the first and most important therapy. For patients receiving ECMO or continuous renal replacement therapy who develop HIT, synthetic thrombin inhibitors have been reported as an alternative. However, little information on their use in extracorporeal life support has been published, particularly in the pediatric population.

CONCLUSION

This report documents a pediatric case of HIT type II successfully treated with argatroban, allowing continuation of the ECMO and continuous renal replacement therapy therapy, with resolution of the cutaneous ischemia and thrombocytopenia.

Heparin-induced thrombocytopenia in a pediatric patient receiving extracorporeal support and treated with argatroban

INTRODUCTION

Heparin-induced thrombocytopenia (HIT) is rare in the pediatric population, with a majority occurring in the pediatric intensive care unit setting. All reported cases have been associated with the use of unfractionated heparin. Because unfractionated heparin is the anticoagulant of choice for extracorporeal life support, the development of HIT in these patients can be devastating. We report a case of HIT with evidence of small-vessel arterial thromboembolism in a 17-month-old child receiving extracorporeal membrane oxygenation and continuous renal replacement therapy successfully treated with argatroban.

CASE

The patient was a 17-month-old boy with severe respiratory failure secondary to asthma and mucus plugging that failed conventional and unconventional ventilation. Venovenous extracorporeal membrane oxygenation was initiated, and within 24 hrs, there was a precipitous decrease in the platelet count, with the development of cutaneous ischemia involving his lower limbs. Heparin-associated antibodies were positive. Argatroban was started, and the child maintained on extracorporeal membrane oxygenation and continuous renal replacement therapy, with resolution of the cutaneous ischemia and rebound of the thrombocytopenia.

DISCUSSION

HIT is rare in the pediatric population. Recognition of HIT is vital because withdrawal of heparin is the first and most important therapy. For patients on extracorporeal membrane oxygenation or continuous renal replacement therapy who develop HIT, synthetic thrombin inhibitors (hirulogs) have been reported as an alternative. However, little information on their use in extracorporeal life support has been published, particularly in the pediatric population.

CONCLUSION

This report documents a pediatric case of HIT successfully treated with argatroban, allowing continuation of the venovenous extracorporeal membrane oxygenation and continuous renal replacement therapy, with resolution of the thromboembolic ischemia and thrombocytopenia.

Extracorporeal carbon dioxide removal to control arterial pH and PACO2 in a heart-beating donor with acute lung injury

BACKGROUND

Arteriovenous carbon dioxide (AVCO2R) removal is a technique of pumpless extracorporeal carbon dioxide removal. This system has been used successively to control pH and PaCO2 in patients with acute lung injury who could not be adequately ventilated. This report describes the use of this technology in an organ donor awaiting harvesting.

METHODS

AVCO2R was implanted using a hollow-fiber oxygenator attached to 12 F and 14 F vascular cannulas that were inserted into the femoral artery and vein, respectively. Oxygen was attached to the oxygenator to provide the sweep gas.

RESULTS

The PaCO2 and arterial pH promptly corrected after support was initiated (from 83-42 mm Hg and 7.18-7.38, respectively).

CONCLUSION

This case describes the successful use of pumpless arteriovenous extracorporeal removal of CO2 in a heart-beating donor awaiting organ harvest.

Serum procalcitonin concentration as a negative predictor of serious bacterial infection in acute sickle cell pain crisis

BACKGROUND

A pilot study was designed to determine if serum procalcitonin levels would assist in the diagnosis of severe bacterial infections in patients presenting to an emergency department (ED) with acute sickle cell pain crisis and evidence of acute inflammatory response.

MATERIAL/METHODS

Prospective single cohort study evaluating measured procalcitonin levels in patients with sickle cell pain crisis and evidence of acute inflammation. Acute inflammation was defined as fever (>38 degrees C) and/or elevation in the white blood cell count (>4000 above baseline) and tachycardia (heart rate >100). Procalcitonin was measured using a semi-quantitative monoclonal antibody test. Patients were followed clinically to determine if procalcitonin has predictive value in excluding severe bacterial infections.

RESULTS

Twenty four subjects were enrolled and completed the study. Sixteen had levels 0.5 ng/ml or less, two had levels 0.5 to 2 ng/ml, one had a level of 2 but less than 10 ng/ml, and four had levels 10 ng/ml or greater. All subjects with documented infections at presentation had procalcitonin levels > or =2.0 ng/ml. The sensitivity of the test in this study sample was 1, and the specificity was 0.95 (95% CI, 0.75-0.99).

CONCLUSIONS

A serum procalcitonin less than 2 ng/ml appears to have good negative predictive value in excluding serious bacterial infections in patients that present with acute sickle cell pain crisis and evidence of acute inflammatory response. Further study is needed to investigate if procalcitonin has positive predictive value in identifying patients with serious bacterial infections in this patient population.

Total extracorporeal arteriovenous carbon dioxide removal in acute respiratory failure: a phase I clinical study

OBJECTIVE

To evaluate the safety and efficacy of pumpless extracorporeal arteriovenous carbon dioxide removal (AVCO2R) in subjects with acute respiratory failure and hypercapnia.

DESIGN

A phase I within-group time series trial in which subjects underwent up to 72 h of support with AVCO2R in intensive care units of two university hospitals.

PATIENTS

Eight patients with acute hypercapnic respiratory failure or hypoxemic respiratory failure managed with permissive hypercapnia.

INTERVENTIONS

Extracorporeal CO2 removal was achieved through percutaneous cannulation of the femoral artery and vein, and a simple extracorporeal circuit using a commercially available membrane gas exchange device for carbon dioxide exchange.

MEASUREMENTS AND RESULTS

Measurements of hemodynamics, blood gases, ventilatory settings, and laboratory values were made before initiation of AVCO2R, and at subsequent intervals for 72 h. PaCO2 decreased significantly from 90.8+/-7.5 mmHg to 52.3+/-4.3 and 51.8+/-3.1 mmHg at 1 and 2 h, respectively. This decrease occurred despite a decrease in minute ventilation from a baseline of 6.92+/-1.64 l/min to 4.22+/-.46 and 3.00+/-.53 l/min at 1 and 2 h. There was a normalization of pH, with an increase from 7.19+/-.06 to 7.35+/-.07 and 7.37+/-.05 at 1 and 2 h. These improvements persisted during the full period of support with AVCO2R. Four subjects underwent apnea trials in which AVCO2R provided total carbon dioxide removal during apneic oxygenation, resulting in steady-state PaCO2 values from 57 to 85 mmHg. Hemodynamics were not significantly altered with the institution of AVCO2R. There were no major complications attributed to the procedure.

CONCLUSION

Pumpless extracorporeal AVCO2R is capable of providing complete extracorporeal removal of carbon dioxide during acute respiratory failure, while maintaining mild to moderate hypercapnia. Applied in conjunction with mechanical ventilation and permissive hypercapnia, AVCO2R resulted in normalization of arterial PCO2 and pH and permitted significant reductions in the level of mechanical ventilation.

Percutaneous extracorporeal arteriovenous CO2 removal for severe respiratory failure

BACKGROUND

In previous animal studies, arteriovenous CO2 removal (AVCO2R) achieved significant reduction in ventilator pressures and improvement in the Pao2 to fraction of inspired oxygen ratio during severe respiratory failure. For our initial clinical experience, 5 patients were approved for treatment of severe respiratory failure and CO2 retention to evaluate the feasibility and safety of percutaneous AVCO2R.

METHODS

Patients were anticoagulated with heparin (activated clotting time, 260 to 300 seconds), underwent percutaneous femoral cannulation (10F to 12F arterial and 12F to 15F venous catheters), and then were connected to a low-resistance, 2.5-m2 hollow-fiber oxygenator for 72 hours.

RESULTS

Mean AVCO2R flow at 24, 48, and 72 hours was 837.4+/-73.9, 873+/-83.6, and 750+/-104.5 mL/min, respectively, with no vascular complications and no significant change in heart rate or mean arterial pressure. Removal of CO2 plateaued at an AVCO2R flow of 1086 mL/min with 208 mL/min CO2 removed. Average CO2 transfer at 24 and 48 hours was 142+/-17 and 129+/-16 mL/min. Use of AVCO2R allowed a significant decrease in minute ventilation from 7.2+/-2.3 L/min at baseline to 3.4+/-0.8 L/min at 24 hours.

CONCLUSIONS

All patients survived the experimental period without adverse sequelae. Percutaneous AVCO2R can achieve approximately 70% CO2 removal in adults with severe respiratory failure and CO2 retention without hemodynamic compromise or instability.

Arteriovenous extracorporeal carbon dioxide removal: a mathematical model and experimental evaluation

To explore the feasibility and operating limits of arteriovenous extracorporeal CO2 removal (AVCO2R) for support of acute respiratory failure, the authors developed a mathematical model to simulate (AVCO2R), evaluate the effects of several parameters used in its application, and predict the feasibility and necessary conditions for total CO2 removal. The mathematical model incorporated compartments representing blood, pulmonary alveoli, pulmonary capillaries, peripheral tissues and capillaries, and an extracorporeal gas exchange device. The model was validated against an animal model of extracorporeal CO2 removal. This model consisted of anesthetized and mechanically ventilated piglets. An extracorporeal CO2 removal device was placed by cannulation of a femoral artery and vein. Dynamic and steady state measurements of CO2 transfer were made and compared with simulations using the mathematical model. There was good agreement between experimental and simulated data, validating the mathematical model under a variety of conditions. The mathematical model was used to determine operating parameters for total CO2 removal. Relationships between extracorporeal blood flow, device diffusing capacity, and device gas sweep flow were established for CO2 removal at various levels of CO2 production. These simulations indicate that it is possible to achieve total CO2 removal using an extracorporeal shunt fraction of 10%-15% of cardiac output, a device diffusing capacity of 0.5 ml x min(-1) x torr(-1) (kg body weight)(-1), and a gas:blood flow of 5 or greater.

Nosocomial pneumonia

Nosocomial pneumonia remains a major cause of morbidity, mortality, and significant hospital cost despite continued refinements in antimicrobial treatment, improved methods for diagnosis, and better supportive and preventive measures. While clinical experience is considerable, appreciation of the epidemiologic and pathogenic factors responsible for NP development and pathogen selection are limited, and consensus regarding optimal prevention and diagnostic and therapeutic strategies is lacking. This article reviews the recent literature with an emphasis on significance, pathogenesis, etiology, and therapy of nosocomial pneumonia.

Intravenacaval membrane oxygenation and carbon dioxide removal in severe acute respiratory failure

STUDY OBJECTIVE

To characterize the physiologic response to, and safety of, intravenacaval membrane oxygenation and carbon dioxide removal.

DESIGN

Interventional before-after study.

SETTING

University teaching hospital ICU.

PATIENTS

Twenty-two patients with severe acute respiratory distress syndrome (ARDS).

INTERVENTIONS

Implantation of a hollow-fiber membrane oxygenator (IVOX; CardioPulmonics; Salt Lake City, Utah) into the superior and inferior venae cavae by venotomy of the right femoral or right internal jugular vein for a duration of up to 20 days.

MEASUREMENTS

Hemodynamic measurements using pulmonary artery and systemic artery catheters, ventilator settings (FIO2, minute ventilation, peak inspiratory pressure, and positive end-expiratory pressure), arterial and mixed venous blood gases (pH, PCO2, PO2, and measured saturation), and clinical laboratory determinations (CBC, fibrinogen, plasma hemoglobin, complement C3 and C5) were obtained. Calculations of PaO2/FIO2 ratio and PaCO2-VE product were used to assess gas exchange efficacy. Microbiologic cultures were obtained from the device and wound following explantation. Survival to ICU discharge and hospital discharge were recorded.

RESULTS

Implantation was successful in 20 of 22 patients. Gas exchange rates averaged 50.4 +/- 15.8 mL.min-1 for carbon dioxide and 71.1 +/- 20.2 mL.min-1 for oxygen. A reduction in FIO2 from 0.78 +/- 0.16 to 0.63 +/- 0.21 and in VE from 177 +/- 94 mL.kg-1.min-1 to 127 +/- 58 mL.kg-1.min-1 was possible within 4 h post-implantation. By 12 h, FIO2 was reduced to 0.57 +/- 0.18. Indices of gas exchange improved significantly after implantation, with PaO2/FIO2 ratio increasing from 79 +/- 20 to 112 +/- 47 and PaCO2-VE product decreasing from 7.6 +/- 4.2 to 4.9 +/- 2.5 within 4 h. A significant reduction in peak inspiratory pressure was achieved (45 +/- 10 to 38 +/- 9 cm H2O). Major complications were blood loss during implantation requiring transfusion in 11 patients, a retroperitoneal bleed in 1 patient, and femoral deep venous thrombosis in 4 patients, but there were no long-term sequelae or IVOX-related deaths. The ICU and hospital survival were 10/20 (50%) and 8/20 (40%), respectively.

CONCLUSIONS

Intravenacaval membrane oxygen and carbon dioxide removal can provide partial respiratory support during severe respiratory failure and permit reductions in the level of mechanical ventilator support, with an acceptable safety profile.