Partial extracorporeal carbon dioxide removal using a standard continuous renal replacement therapy device: a preliminary study.
Quintard Jean-Marie,Barbot Olivier,Thevenot Florence,de Matteis Olivier,Benayoun Laurent,Leibinger Frank
ASAIO journal (American Society for Artificial Internal Organs : 1992)
To test the feasibility, safety, and efficacy of partial extracorporeal CO2 removal (PECCO2R) using a standard continuous renal replacement (CRRT) device with a pediatric oxygenation membrane introduced into the circuit in a serial manner. In this retrospective single-center study, we have studied mechanically ventilated patients with persistent significant respiratory acidosis and acute renal failure requiring ongoing CRRT. Sixteen patients were treated with our PECCO2R device. PaCO2 and arterial pH were measured before as well as at 6 and 12 hours after PECCO2R implementation. Hemodynamic parameters were continuously monitored. Our PECCO2R system was efficient to significantly reduce PaCO2 and increase arterial pH. The median PaCO2 before treatment was 77 mm Hg (59-112) with a median reduction of 24 mm Hg after 6 hours and 30 mm Hg after 12 hours (31% and 39%, respectively). The median pH increase was 0.16 at 6 hours and 0.23 at 12 hours. Partial extracorporeal CO2 removal treatment had no effect on oxygenation. No complication was observed. Our PECCO2R approach based on the simple introduction of a pediatric extracorporeal membrane oxygenation membrane into the circuit of a standard CRRT device is easy to implement, safe, and efficient to improve respiratory acidosis.
Extracorporeal carbon dioxide removal through ventilation of acidified dialysate: an experimental study.
Zanella Alberto,Mangili Paolo,Giani Marco,Redaelli Sara,Scaravilli Vittorio,Castagna Luigi,Sosio Simone,Pirrone Federica,Albertini Mariangela,Patroniti Nicolò,Pesenti Antonio
The Journal of heart and lung transplantation : the official publication of the International Society for Heart Transplantation
BACKGROUND:Extracorporeal (EC) carbon dioxide (CO(2)) removal (ECCO(2)R) may be a powerful alternative to ventilation, possibly avoiding the need for mechanical ventilation and endotracheal intubation. We previously reported how an infusion of lactic acid before a membrane lung (ML) effectively enhances ECCO(2)R. We evaluated an innovative ECCO(2)R technique based on ventilation of acidified dialysate. METHODS:Four swine were sedated, mechanically ventilated, and connected to a venovenous dialysis circuit (blood flow, 250 ml/min). The dialysate was recirculated in a closed loop circuit including a ML (gas flow, 10 liters/min) and then returned to the dialyzer. In each animal, 4 different dialysis flows (DF) of 200, 400, 600, and 800 ml/min were evaluated with and without lactic acid infusion (2.5 mEq/min); the sequence was completed 3 times. At the end of each step, we measured the volume of CO(2)R by the ML (V(co2)ML) and collected blood and dialysate samples for gas analyses. RESULTS:Acid infusion substantially increased V(co2)ML, from 33 ± 6 ml/min to 86 ± 7 ml/min. Different DFs had little effect on V(co2)ML, which was only slightly reduced at DF 200 ml/min. The partial pressure of CO(2) of blood passing through the dialysis filter changed from 60.9 ± 3.6 to 37.1 ± 4.8 mm Hg without acidification and to 32.5 ± 5.3 mm Hg with acidification, corresponding to a pH increase of 0.18 ± 0.03 and 0.03 ± 0.04 units, respectively. CONCLUSIONS:Ventilation of acidified dialysate efficiently increased ECCO(2)R of an amount corresponding to 35% to 45% of the total CO(2) production of an adult man from a blood flow as low as 250 ml/min.
Acidic sweep gas with carbonic anhydrase coated hollow fiber membranes synergistically accelerates CO2 removal from blood.
Arazawa D T,Kimmel J D,Finn M C,Federspiel W J
UNLABELLED:The use of extracorporeal carbon dioxide removal (ECCO2R) is well established as a therapy for patients suffering from acute respiratory failure. Development of next generation low blood flow (<500 mL/min) ECCO2R devices necessitates more efficient gas exchange devices. Since over 90% of blood CO2 is transported as bicarbonate (HCO3(-)), we previously reported development of a carbonic anhydrase (CA) immobilized bioactive hollow fiber membrane (HFM) which significantly accelerates CO2 removal from blood in model gas exchange devices by converting bicarbonate to CO2 directly at the HFM surface. This present study tested the hypothesis that dilute sulfur dioxide (SO2) in oxygen sweep gas could further increase CO2 removal by creating an acidic microenvironment within the diffusional boundary layer adjacent to the HFM surface, facilitating dehydration of bicarbonate to CO2. CA was covalently immobilized onto poly (methyl pentene) (PMP) HFMs through glutaraldehyde activated chitosan spacers, potted in model gas exchange devices (0.0151 m(2)) and tested for CO2 removal rate with oxygen (O2) sweep gas and a 2.2% SO2 in oxygen sweep gas mixture. Using pure O2 sweep gas, CA-PMP increased CO2 removal by 31% (258 mL/min/m(2)) compared to PMP (197 mL/min/m(2)) (P<0.05). Using 2.2% SO2 acidic sweep gas increased PMP CO2 removal by 17% (230 mL/min/m(2)) compared to pure oxygen sweep gas control (P<0.05); device outlet blood pH was 7.38 units. When employing both CA-PMP and 2.2% SO2 sweep gas, CO2 removal increased by 109% (411 mL/min/m(2)) (P<0.05); device outlet blood pH was 7.35 units. Dilute acidic sweep gas increases CO2 removal, and when used in combination with bioactive CA-HFMs has a synergistic effect to more than double CO2 removal while maintaining physiologic pH. Through these technologies the next generation of intravascular and paracorporeal respiratory assist devices can remove more CO2 with smaller blood contacting surface areas. STATEMENT OF SIGNIFICANCE:A clinical need exists for more efficient respiratory assist devices which utilize low blood flow rates (<500 mL/min) to regulate blood CO2 in patients suffering from acute lung failure. Literature has demonstrated approaches to chemically increase hollow fiber membrane (HFM) CO2 removal efficiency by shifting equilibrium from bicarbonate to gaseous CO2, through either a bioactive carbonic anhydrase enzyme coating or bulk blood acidification with lactic acid. In this study we demonstrate a novel approach to local blood acidification using an acidified sweep gas in combination with a bioactive coating to more than double CO2 removal efficiency of HFM devices. To our knowledge, this is the first report assessing an acidic sweep gas to increase CO2 removal from blood using HFM devices.
Extracorporeal Lung Support for Hypercapnic Ventilatory Failure.
Pisani Lara,Polastri Massimiliano,Pacilli Angela Maria Grazia,Nava Stefano
Extracorporeal lung support can be achieved using extracorporeal membrane oxygenation (ECMO) and extracorporeal CO removal. The ECMO systems allow a total lung support, providing both blood oxygenation and CO removal. Unlike ECMO, extracorporeal CO removal refers to an extracorporeal circuit that provides a partial lung support and selectively extracts CO from blood. The concept of partial extracorporeal lung support by removing only CO without effect on oxygenation was first proposed in 1977 by Kolobow and Gattinoni, with the aim to reduce breathing frequency, ventilator tidal volumes, and inspiratory pressures, facilitating lung-protective ventilation. Patients with end-stage chronic lung disease can survive, while waiting for lung transplantation, only if treated with mechanical ventilation or extracorporeal lung support. ECMO has been considered a suitable approach as a bridge to lung transplantation for patients with advanced respiratory failure waiting for lung transplantation. Extracorporeal CO removal has been proposed for the treatment of COPD patients suffering from exacerbation to avoid invasive mechanical ventilation. The rationale is to combine the improvement of alveolar ventilation by using noninvasive ventilation with muscle unload provided by removing CO directly from the blood, using an extracorporeal device. Increasing attention has been given to the possibility of patients performing a variety of physical activities while receiving extracorporeal lung support. This is possible thanks to the continuous development of technology together with the customization of sedative protocols. Awake extracorporeal support is a specific approach in which the patient is awake and potentially cooperative while receiving ECMO. The present analysis aims to synthesize the main results obtained by using extracorporeal circuits in patients with respiratory failure, particularly in those patients with hypercapnia.
Extracorporeal CO2 removal in critically ill patients: a systematic review.
Taccone Fabio S,Malfertheiner Maximilian V,Ferrari Fiorenza,Di Nardo Matteo,Swol Justyna,Broman Lars M,Vercaemst Leen,Barrett Nicholas,Pappalardo Federico,Belohlavek Jan,Mueller Thomas,Lorusso Roberto,Belliato Mirko,
INTRODUCTION:The use of extracorporeal CO2 removal (ECCO2R) is increasingly employed in critically ill patients. However, the clinical evidence supporting its efficacy remains currently poor. EVIDENCE ACQUISITION:A systematic review using MEDLINE via PubMed was performed to identify eligible studies (until 30th September 2016). The amount of CO2 reduction, the effect on the duration of mechanical ventilation and weaning, the impact on patients' outcome and the occurrence of complications were evaluated. The quality of evidence was evaluated according to the GRADE (Grading of Recommendations Assessment, Development and Evaluation) criteria. EVIDENCE SYNTHESIS:Six studies were included (three evaluating patients with chronic obstructive pulmonary disease [COPD]; three evaluating patients with acute respiratory distress syndrome [ARDS]), involving 279 adult patients; 142 treated with ECCO2R and 137 controls. No study on pediatric population met the inclusion criteria for analysis. The overall quality of evidence of the two randomized trials and four case-control studies varied from moderate to very low. PaCO2 was generally reduced by 25-33% within a few hours following ECCO2R initiation. One ARDS study showed a significant decrease in the duration of mechanical ventilation, although this result was only found by post-hoc analysis. The three studies on COPD demonstrated that some patients supported by ECCO2R devices could avoid endotracheal intubation, however the ICU-LOS and survival was not influenced by ECCO2R when compared to controls. CONCLUSIONS:In COPD patients, a significantly reduced need for endotracheal intubation was reported. However, the use of ECCO2R has not shown significant improvement on the outcome of critically ill patients in the reviewed studies. Therefore appropriately powered, randomized, controlled studies are urgently needed.
Enhanced Extracorporeal CO2 Removal by Regional Blood Acidification: Effect of Infusion of Three Metabolizable Acids.
Scaravilli Vittorio,Kreyer Stefan,Linden Katharina,Belenkiy Slava,Pesenti Antonio,Zanella Alberto,Cancio Leopoldo C,Batchinsky Andriy I
ASAIO journal (American Society for Artificial Internal Organs : 1992)
Acidification of blood entering a membrane lung (ML) with lactic acid enhances CO2 removal (VCO2ML). We compared the effects of infusion of acetic, citric, and lactic acids on VCO2ML. Three sheep were connected to a custom-made circuit, consisting of a Hemolung device (Alung Technologies, Pittsburgh, PA), a hemofilter (NxStage, NxStage Medical, Lawrence, MA), and a peristaltic pump recirculating ultrafiltrate before the ML. Blood flow was set at 250 ml/min, gas flow (GF) at 10 L/min, and recirculating ultrafiltrate flow at 100 ml/min. Acetic (4.4 M), citric (0.4 M), or lactic (4.4 M) acids were infused in the ultrafiltrate at 1.5 mEq/min, for 2 hours each, in randomized fashion. VCO2ML was measured by the Hemolung built-in capnometer. Circuit and arterial blood gas samples were collected at baseline and during acid infusion. Hemodynamics and ventilation were monitored. Acetic, citric, or lactic acids similarly enhanced VCO2ML (+35%), from 37.4 ± 3.6 to 50.6 ± 7.4, 49.8 ± 5.6, and 52.0 ± 8.2 ml/min, respectively. Acids similarly decreased pH, increased pCO2, and reduced HCO3 of the post-acid extracorporeal blood sample. No significant effects on arterial gas values, ventilation, or hemodynamics were observed. In conclusion, it is possible to increase VCO2ML by more than one-third using any one of the three metabolizable acids.
Effect of Hematocrit on the CO2 Removal Rate of Artificial Lungs.
May Alexandra G,Omecinski Katelin S,Frankowski Brian J,Federspiel William J
ASAIO journal (American Society for Artificial Internal Organs : 1992)
Extracorporeal CO2 removal (ECCO2R) can permit lung protective or noninvasive ventilation strategies in patients with chronic obstructive pulmonary disease (COPD) and acute respiratory distress syndrome (ARDS). With evidence supporting ECCO2R growing, investigating factors which affect CO2 removal is necessary. Multiple factors are known to affect the CO2 removal rate (vCO2) which can complicate the interpretation of changes in vCO2; however, the effect of hematocrit on the vCO2 of artificial lungs has not been investigated. This in vitro study evaluates the relationship between hematocrit level and vCO2 within an ECCO2R device. In vitro gas transfer was measured in bovine blood in accordance with the ISO 7199 standard. Plasma and saline were used to hemodilute the blood to hematocrits between 33% and 8%. The vCO2 significantly decreased as the blood was hemodiluted with saline and plasma by 42% and 32%, respectively, between a hematocrit of 33% and 8%. The hemodilution method did not significantly affect the vCO2. In conclusion, the hematocrit level significantly affects vCO2 and should be taken into account when interpreting changes in the vCO2 of an ECCO2R device.
A novel pump-driven veno-venous gas exchange system during extracorporeal CO2-removal.
Hermann Alexander,Riss Katharina,Schellongowski Peter,Bojic Andja,Wohlfarth Philipp,Robak Oliver,Sperr Wolfgang R,Staudinger Thomas
Intensive care medicine
PURPOSE:Pump-driven veno-venous extracorporeal CO2-removal (ECCO2-R) increasingly takes root in hypercapnic lung failure to minimize ventilation invasiveness or to avoid intubation. A recently developed device (iLA activve(®), Novalung, Germany) allows effective decarboxylation via a 22 French double lumen cannula. To assess determinants of gas exchange, we prospectively evaluated the performance of ECCO2-R in ten patients receiving iLA activve(®) due to hypercapnic respiratory failure. METHODS:Sweep gas flow was increased in steps from 1 to 14 L/min at constant blood flow (phase 1). Similarly, blood flow was gradually increased at constant sweep gas flow (phase 2). At each step gas transfer via the membrane as well as arterial blood gas samples were analyzed. RESULTS:During phase 1, we observed a significant increase in CO2 transfer together with a decrease in PaCO2 levels from a median of 66 mmHg (range 46-85) to 49 (31-65) mmHg from 1 to 14 L/min sweep gas flow (p < 0.0001), while arterial oxygenation deteriorated with high sweep gas flow rates. During phase 2, oxygen transfer significantly increased leading to an increase in PaO2 from 67 (49-87) at 0.5 L/min to 117 (66-305) mmHg at 2.0 L/min (p < 0.0001). Higher blood flows also significantly enhanced decarboxylation (p < 0.0001). CONCLUSIONS:Increasing sweep gas flow results in effective CO2-removal, which can be further reinforced by raising blood flow. The clinically relevant oxygenation effect in this setting could broaden the range of indications of the system and help to set up an individually tailored configuration.
Effect of extracorporeal CO2 removal on right ventricular and hemodynamic parameters in a patient with acute respiratory distress syndrome.
Cherpanath Thomas G V,Landburg Pearl P,Lagrand Wim K,Schultz Marcus J,Juffermans Nicole P
We present a female patient with severe acute respiratory distress syndrome (ARDS) necessitating intubation and mechanical ventilation on the intensive care unit (ICU). High ventilatory pressures were needed because of hypoxia and severe hypercapnia with respiratory acidosis, resulting in right ventricular dysfunction with impaired haemodynamic stability. A veno-venous extracorporeal CO2 removal (ECCO2R) circuit was initiated, effectively eliminating carbon dioxide while improving oxygenation and enabling a reduction in applied ventilatory pressures. We noted a marked improvement of right ventricular function with restoration of haemodynamic stability. Within one week, the patient was weaned from both ECCO2R and mechanical ventilation. Besides providing adequate gas exchange, extracorporeal assist devices may be helpful in ameliorating right ventricular dysfunction during ARDS.
ECCOR therapy in the ICU: consensus of a European round table meeting.
Combes Alain,Auzinger Georg,Capellier Gilles,du Cheyron Damien,Clement Ian,Consales Guglielmo,Dabrowski Wojciech,De Bels David,de Molina Ortiz Francisco Javier González,Gottschalk Antje,Hilty Matthias P,Pestaña David,Sousa Eduardo,Tully Redmond,Goldstein Jacques,Harenski Kai
Critical care (London, England)
BACKGROUND:With recent advances in technology, patients with acute respiratory distress syndrome (ARDS) and severe acute exacerbations of chronic obstructive pulmonary disease (ae-COPD) could benefit from extracorporeal CO removal (ECCOR). However, current evidence in these indications is limited. A European ECCOR Expert Round Table Meeting was convened to further explore the potential for this treatment approach. METHODS:A modified Delphi-based method was used to collate European experts' views to better understand how ECCOR therapy is applied, identify how patients are selected and how treatment decisions are made, as well as to identify any points of consensus. RESULTS:Fourteen participants were selected based on known clinical expertise in critical care and in providing respiratory support with ECCOR or extracorporeal membrane oxygenation. ARDS was considered the primary indication for ECCOR therapy (n = 7), while 3 participants considered ae-COPD the primary indication. The group agreed that the primary treatment goal of ECCOR therapy in patients with ARDS was to apply ultra-protective lung ventilation via managing CO levels. Driving pressure (≥ 14 cmHO) followed by plateau pressure (P; ≥ 25 cmHO) was considered the most important criteria for ECCOR initiation. Key treatment targets for patients with ARDS undergoing ECCOR included pH (> 7.30), respiratory rate (< 25 or < 20 breaths/min), driving pressure (< 14 cmHO) and P (< 25 cmHO). In ae-COPD, there was consensus that, in patients at risk of non-invasive ventilation (NIV) failure, no decrease in PaCO and no decrease in respiratory rate were key criteria for initiating ECCOR therapy. Key treatment targets in ae-COPD were patient comfort, pH (> 7.30-7.35), respiratory rate (< 20-25 breaths/min), decrease of PaCO (by 10-20%), weaning from NIV, decrease in HCO and maintaining haemodynamic stability. Consensus was reached on weaning protocols for both indications. Anticoagulation with intravenous unfractionated heparin was the strategy preferred by the group. CONCLUSIONS:Insights from this group of experienced physicians suggest that ECCOR therapy may be an effective supportive treatment for adults with ARDS or ae-COPD. Further evidence from randomised clinical trials and/or high-quality prospective studies is needed to better guide decision making.
Practical Clinical Application of an Extracorporeal Carbon Dioxide Removal System in Acute Respiratory Distress Syndrome and Acute on Chronic Respiratory Failure.
Grasselli Giacomo,Castagna Luigi,Bottino Nicola,Scaravilli Vittorio,Corcione Nadia,Guzzardella Amedeo,Bonifazi Matteo,Rossi Nicola,Zanella Alberto,Pesenti Antonio
ASAIO journal (American Society for Artificial Internal Organs : 1992)
We retrospectively reviewed the medical records of 11 patients supported with a veno-venous low-flow extracorporeal carbon dioxide (CO2) removal (ECCO2R) device featuring a large gas exchange surface membrane lung (ML) (i.e., 1.8 m). Seven patients suffered from exacerbation of a chronic pulmonary disease, while four subjects were affected by acute respiratory distress syndrome (ARDS). Twenty-four hours of ECCO2R treatment reduced arterial PCO2 from 63 ± 12 to 54 ± 11 mm Hg (p < 0.01), increased arterial pH from 7.29 ± 0.07 to 7.39 ± 0.06 (p < 0.01), and decreased respiratory rate from 32 ± 10 to 21 ± 8 bpm (p < 0.05). Extracorporeal blood flow and CO2 removal were 333 ± 37 and 94 ± 18 ml/min, respectively. The median duration of ECCO2R treatment was 7 days (6.5-9.5). All four ARDS patients were invasively ventilated at the time of treatment start, no one was extubated and they all died. Among the seven patients with exacerbation of chronic pulmonary diseases, four were managed with noninvasive ventilation at ECCO2R institution, while three were extubated after starting the extracorporeal treatment. No one of these seven patients was intubated or re-intubated after ECCO2R institution and five (71%) survived to hospital discharge. A low-flow ECCO2R device with a large surface ML removes a relevant amount of CO2 resulting in a decreased arterial PCO2, an increased arterial pH, and in a reduced ventilatory load.
The use of extracorporeal carbon dioxide removal in acute chronic obstructive pulmonary disease exacerbation: a narrative review.
d'Andrea Alexia,Banfi Carlo,Bendjelid Karim,Giraud Raphaël
Canadian journal of anaesthesia = Journal canadien d'anesthesie
Chronic obstructive pulmonary disease (COPD) exacerbation induces hypercapnic respiratory acidosis. Extracorporeal carbon dioxide removal (ECCOR) aims to eliminate blood carbon dioxide (CO) in order to reduce adverse effects from hypercapnia and the related acidosis. Hypercapnia has deleterious extra-pulmonary consequences in increasing intracranial pressure and inducing and/or worsening right heart failure. During COPD exacerbation, the use of ECCOR may improve the efficacy of non-invasive ventilation (NIV) in terms of CO removal, decrease respiratory rate and reduce dynamic hyperinflation and intrinsic positive end expiratory pressure, which all contribute to increasing dead space. Moreover, ECCOR may prevent NIV failure while facilitating the weaning of intubated patients from mechanical ventilation. In this review of the literature, the authors will present the current knowledge on the pathophysiology related to COPD, the principles of the ECCOR technique and its role in acute and severe decompensation of COPD. However, despite technical advances, there are only case series in the literature and few prospective studies to clearly establish the role of ECCOR in acute and severe COPD decompensation.
Low-Flow Extracorporeal Carbon Dioxide Removal Using the Hemolung Respiratory Dialysis System to Facilitate Lung-Protective Mechanical Ventilation in Acute Respiratory Distress Syndrome.
Akkanti Bindu,Rajagopal Keshava,Patel Kirti P,Aravind Sangeeta,Nunez-Centanu Emmanuel,Hussain Rahat,Shabari Farshad Raissi,Hofstetter Wayne L,Vaporciyan Ara A,Banjac Igor S,Kar Biswajit,Gregoric Igor D,Loyalka Pranav
The journal of extra-corporeal technology
Extracorporeal carbon dioxide removal (ECCOR) permits reductions in alveolar ventilation requirements that the lungs would otherwise have to provide. This concept was applied to a case of hypercapnia refractory to high-level invasive mechanical ventilator support. We present a case of an 18-year-old man who developed post-pneumonectomy acute respiratory distress syndrome (ARDS) after resection of a mediastinal germ cell tumor involving the left lung hilum. Hypercapnia and hypoxemia persisted despite ventilator support even at traumatic levels. ECCOR using a miniaturized system was instituted and provided effective carbon dioxide elimination. This facilitated establishment of lung-protective ventilator settings and lung function recovery. Extracorporeal lung support increasingly is being applied to treat ARDS. However, conventional extracorporeal membrane oxygenation (ECMO) generally involves using large cannulae capable of carrying high flow rates. A subset of patients with ARDS has mixed hypercapnia and hypoxemia despite high-level ventilator support. In the absence of profound hypoxemia, ECCOR may be used to reduce ventilator support requirements to lung-protective levels, while avoiding risks associated with conventional ECMO.
Long-Term Venovenous Connection for Extracorporeal Carbon Dioxide Removal (ECCOR)-Numerical Investigation of the Connection to the Common Iliac Veins.
Steuer N B,Hugenroth K,Beck T,Spillner J,Kopp R,Reinartz S,Schmitz-Rode T,Steinseifer U,Wagner G,Arens J
Cardiovascular engineering and technology
PURPOSE:Currently used cannulae for extracorporeal carbon dioxide removal (ECCOR) are associated with complications such as thrombosis and distal limb ischemia, especially for long-term use. We hypothesize that the risk of these complications is reducible by attaching hemodynamically optimized grafts to the patient's vessels. In this study, as a first step towards a long-term stable ECCOR connection, we investigated the feasibility of a venovenous connection to the common iliac veins. To ensure its applicability, the drainage of reinfused blood (recirculation) and high wall shear stress (WSS) must be avoided. METHODS:A reference model was selected for computational fluid dynamics, on the basis of the analysis of imaging data. Initially, a sensitivity analysis regarding recirculation was conducted using as variables: blood flow, the distance of drainage and return to the iliocaval junction, as well as the diameter and position of the grafts. Subsequently, the connection was optimized regarding recirculation and the WSS was evaluated. We validated the simulations in a silicone model traversed by dyed fluid. RESULTS:The simulations were in good agreement with the validation measurements (mean deviation 1.64%). The recirculation ranged from 32.1 to 0%. The maximum WSS did not exceed 5.57 Pa. The position and diameter of the return graft show the highest influence on recirculation. A correlation was ascertained between recirculation and WSS. Overall, an inflow jet directed at a vessel wall entails not only high WSS, but also a flow separation and thereby an increased recirculation. Therefore, return grafts aligned to the vena cava are crucial. CONCLUSION:In conclusion, a connection without recirculation could be feasible and therefore provides a promising option for a long-term ECCOR connection.
Extracorporeal Carbon Dioxide Removal in the Management of Complex Bilateral Flail Chest Injury.
Wells Adam H,Oswald Todd J,Samra Navdeep,Scott L Keith,Conrad Steven A
ASAIO journal (American Society for Artificial Internal Organs : 1992)
Flail chest is an uncommon consequence of traumatic injury. Medical management includes mechanical ventilation for internal pneumatic stabilization. Control of respiratory drive is necessary to avoid paradoxical movement and impairment of recovery. Traditional approaches include sedation and neuromuscular blockade, but these measures are at odds with current trends of keeping patients awake and implementing active rehabilitation. We hypothesized that extracorporeal carbon dioxide removal (ECCO2R) would suppress the respiratory drive sufficiently to permit synchronous mechanical ventilation, allowing rib fracture healing in an awake patient with extensive bilateral flail chest. A patient with 21 fractures underwent ECCO2R for 6 weeks to permit internal pneumatic stabilization with mechanical ventilation, targeting a partial pressure of carbon dioxide in arterial blood (PaCO2) of 25-30 mm Hg. The first 2 weeks were performed with extracorporeal membrane oxygenation (ECMO) for bilateral pulmonary contusions and acute respiratory distress syndrome. The last 4 weeks was with low-flow ECCO2R. Respiratory drive was suppressed during both ECMO and ECCO2R phases when the targeted hypocapnia range of 25-30 mm Hg was achieved, permitting synchronous positive pressure ventilation in an awake and cooperative patient undergoing active rehabilitation. Extracorporeal carbon dioxide removal targeting hypocapnia is a potential adjunct in extensive flail chest injury undergoing nonsurgical management.