The use of extracorporeal carbon dioxide removal in the management of life-threatening bronchospasm due to influenza infection

We report the use of the Novalung interventional Lung Assist extracorporeal carbon dioxide removal device, (Novalung GmbH, Lotzenacker 3, D-72379 Hechingen, Germany) to treat a 46-year-old female with life-threatening bronchospasm secondary to influenza infection. Despite maximal treatment she developed severe hypercapnia and acidosis. The necessity for high inflation pressures led to the development of gross surgical emphysema. Use of the interventional Lung Assist enabled a rapid correction of hypercapnoea and acidosis, allowing a reduction in airway pressures, reducing further barotrauma. Subsequent resolution of the inflammatory process allowed removal of the interventional Lung Assist after 11 days. She was successfully weaned from mechanical ventilation and made a full recovery.     

体外膜肺氧合在肺移植麻醉中的应用

目的 总结肺移植麻醉中体外膜肺氧合(extracorporeal memberane oxygenation,ECMO)辅助的适应证及术中运用ECMO支持的经验.方法 58例终末期肺病患者在麻醉诱导气管插管后,常规给予非术侧单肺通气30 min,监测肺动脉压(PAP)、氧分压(PaO2)、二氧化碳分压(PaCO2)、肺泡气·动脉氧分压差(PA-aO2)和呼吸力学等指标,根据监测指标调节机械通气参数,必要时行手控通气.17例患者分别因肺动脉高压、低氧血症和高碳酸血症而给予ECMO辅助,转流期间维持激活凝血时间(ACT)160秒～200秒,流量控制在1.8 L·m-2·min-1～2.5 L·m-2·min-1.结果 所有患者ECMO转流后PAP及PaCO:下降明显,氧合改善.麻醉伞程生命体征平稳.手术经过顺利.结论 ECMO是肺移植术中肺辅助的有效手段,可提高肺移植手术的麻醉成功率.原发性肺动脉高压、肺纤维化合并肺动脉高压、严重的低氧血症和高碳酸血症是肺移植术中ECMO转流的适应证.     

Tattoo removal with the carbon dioxide laser.

Our preliminary experience with tattoo removal utilizing the carbon dioxide laser at the Vancouver General Hospital is reviewed. We developed the method by trial and error until we produced a system yielding an acceptable procedure time with good results.     

Modes of extracorporeal circulation system with the membrane lung

In the extracorporeal circulation with the use of Landé-Edwards membrane lung three different modes of circuit are presently available, i.e., modification of Thomas Buffes' (circuit A), Original Landé's circuit (circuit B) and venous drainage system (circuit C). When the circuit B is used, pressure in the membrane lung becomes higher than arterial blood pressure and in this case it is necessary for the membrane to be strong enough to withstand the high pressure. The great advantage of use of circuit B is minimal hemolysis of three circuits. Circuit A has recirculation system and oxygenation of blood is better than in the other two types, but hemolysis induced is greater than circuit B. Circuit C originally used by Carlson and Landé was found to cause remarkable blood damage and hence it is not to be used in clinical cases. With the membrane of better gas exchange capacity recirculation of blood would become unnecessary and undue hemolysis can be avoided. To improve gas exchange the membrane must be thinner while stong enough to withstand the pressure difference. To avoid excessive pressure difference across the membrane which may cause rupture of the membrane and blood damage, two pumps should be placed at the proximal and distal side of the membrane lung respectively and they must be synchronized precisely. Synchronization of two pumps with membrane lung between them will be left to further study. Among three different types of circuit available at present the best choice is circuit B in which least hemolysis occurs.     

Comparison of a new heparin-coated dense membrane lung with nonheparin-coated dense membrane lung for prolonged extracorporeal lung assist in goats

Thrombosis and bleeding are major complications in cases of prolonged extracorporeal lung assist (ECLA) with an artificial-membrane lung. Antithrombogenic treatment of the artificial-membrane oxygenator and circuits is indispensable for safe ECLA. The efficacy of a new heparin-coated membrane lung with minimal systemic heparinization was evaluated for 7 days and compared with a nonheparin-coated membrane lung in goats. The animals were randomly assigned to either the heparin-coated membrane group (HM group, n = 5) or nonheparin-coated membrane group (NHM group, n = 5). Activated coagulation time (ACT) during ECLA was controlled to below 150 s in the HM group, and to near 200 s in the NHM group. All goats in the HM group were sustained on ECLA for 7 days, but two goats in the NHM group died on the 4th and 6th days, respectively. The mean systemic administration rate of heparin during ECLA was 22.4 +/- 4.4 U/kg/h in the HM group and 39.0 +/- 10.0 U/kg/h in the NHM group. There was a significant difference between the two groups (P < 0.05). The oxygen transfer rate, the Pco(2) difference, the perfusion resistance, and platelet counts showed no significant changes. There was no plasma leakage from the artificial lung. Although several clots were observed in the stagnant areas of the artificial lung, they did not lead to deterioration of the function of the artificial lung. The excellent antithrombogenicity, gas exchange ability, and durability of this new artificial lung with circuits might contribute to successful prolonged ECLA with minimal systemic heparinization.     

Traumatic lung injury treated by extracorporeal membrane oxygenation (ECMO)

BACKGROUND: Conventional mechanical ventilation is the mainstay of treatment for severe respiratory failure associated with trauma. However, when extensive lung injury is present, this technique may not be sufficient to prevent hypoxia, and furthermore, may exacerbate pulmonary damage by barotrauma. Extracorporeal membrane oxygenation (ECMO) has been used successfully in critically ill adult trauma patients and can offer an additional treatment modality. This study reports the use of ECMO in a cohort of adults referred with severe respiratory failure following trauma. METHODS: Retrospective analysis over an 8-year period of all 28 adult patients referred to a single tertiary unit for ECMO support. Survival relative to Injury severity score (ISS), lung injury score (Murray grade), duration of treatment and patient age was evaluated. RESULTS: Twenty of 28 patients who received ECMO with severe trauma related respiratory failure (mean PaO2/FiO2 of 62 mmHg) survived. Most patients had long bone fractures, blunt chest trauma, or combined injuries. Lung injury and injury severity scores, patient age, ECMO duration and oxygenation indices pre-ECMO (PaO2/FiO2) were similar in both the survivor and non-survivor groups. CONCLUSION: A high proportion of trauma patients treated with ECMO for severe lung injury survived. This outcome appears to compare favourably to conventional ventilation techniques and may have a role in patients who develop acute severe respiratory distress associated with trauma.     

Percutaneous extracorporeal arteriovenous carbon dioxide removal improves survival in respiratory distress syndrome: a prospective randomized outcomes study in adult sheep

OBJECTIVE: Arteriovenous carbon dioxide removal (AVCO(2)R) uses a simple arteriovenous shunt for CO(2) removal to minimize barotrauma/volutrauma from mechanical ventilation. We performed a prospective randomized outcomes study of AVCO(2)R in our new, clinically relevant model of respiratory distress syndrome. METHODS: Adult sheep (n = 18) received an LD(50) severe smoke inhalation and 40% third-degree burn. When respiratory distress syndrome developed (PaO (2)/FIO (2) < 200 at 40 to 48 hours), animals were randomized to the AVCO(2)R (n = 9) or sham group (n = 9) for 7 days. Ventilator management protocols mandated reductions in minute ventilation, first tidal volume to peak inspiratory pressure less than 30 cm H(2)O, then respiratory rate when PaCO (2) was less than 40 mm Hg. PaO (2) was kept above 60 mm Hg by adjusting FIO (2). When FIO (2) was 0.21, animals were weaned. RESULTS: The study required 2946 animal-hours of critical care with 696 AVCO(2)R hours. One died in each group during model development. AVCO(2)R flow from 820 mL/min to 970 mL/min (11% to 14% cardiac output) removed CO(2) at a rate of 92 to 116 mL/min (mean 103 mL/min; 93%-97% of CO(2) production). Heart rate, mean arterial pressure, cardiac output, and pulmonary arterial wedge pressure remained relatively constant. Within 48 hours, AVCO(2)R allowed significant ventilator reductions versus baseline in the following measurements: tidal volume (420 to 270 mL), peak inspiratory pressure (25 to 14 cm H(2)O), minute ventilation (13 to 5 L/min), respiratory rate (26 to 16 breaths/min), and FIO (2) (0.88 to 0.35). Ventilator-free days with AVCO(2)R were 3.9 versus 0.2 (P <.01) for sham animals, and ventilator-dependent days with AVCO(2)R were 2.4 versus 6.2 (P <.01) for the 3 sham survivors. All 8 AVCO(2)R animals and 3 of 8 sham animals survived 7 days after randomization. CONCLUSIONS: Percutaneous AVCO(2)R achieved significant reduction in airway pressures, increased ventilator-free days, decreased ventilator-dependent days, and improved survival in a sheep model of respiratory distress syndrome.     

Institutional experience with extracorporeal membrane oxygenation in lung transplantation.

Background: Extracorporeal membrane oxygenation (ECMO) is currently accepted in lung transplantation either to bridge patients to transplantation or to treat postoperatively arising severe primary graft failure. Based on promising initial experiences we have since 2001 implemented ECMO as the standard of intraoperative extracorporeal support in lung transplantation (LuTX) patients with haemodynamic or respiratory instability with the potential to prolong ECMO support into the perioperative period. The aim of this paper is to summarise our total experience with the use of ECMO in LuTX. Methods: We retrospectively reviewed all 306 patients undergoing primary lung transplantation from 1/2001 to 1/2006 with regard to the different forms of ECMO use. Results of all patients requiring ECMO were compared to those without ECMO during the observation period. Results: ECMO was used in 147 patients in total. Two patients were bridged to transplantation. A total of 130 patients received intraoperative ECMO support. In 51 of these patients ECMO was prolonged into the perioperative period. Five of these patients required ECMO support again in the postoperative period due to graft dysfunction. Contrary cardiopulmonary bypass was used in 27 patients mainly with concomitant cardiac defects. Eleven of these patients needed therapeutic ECMO in the further course. A total of 149 patients without relevant risk factors were transplanted without any intraoperative extracorporeal support. Six of these patients required ECMO support in the postoperative period for treatment of primary graft dysfunction. Overall 3-month, 1-year and 3-year survival rates were 88.6%, 82.1% and 74.63%. The mentioned survival rates were 85.4%, 74.2% and 67.6% in the intraoperative+/-prolonged ECMO group; 93.5%, 91.9% and 86.5% in the no support group and 74.0%, 65.9% and 57.7% in the CPB group. Conclusion: ECMO is a valuable tool in lung transplantation providing the potential to bridge patients to transplantation, to replace CPB with at least equal results and to overcome severe postoperative complications. Favourable survival rates can be achieved despite the fact that ECMO is used in the more complex patient population undergoing lung transplantation as well as to overcome already established severe complications.     

经股动静脉置管犬体外膜肺氧合模型的建立

目的探讨在犬体外膜肺氧合（ECMO）实验模型中快速建立血管通路的最佳血管插管技术,以及半切开直视下切口内穿刺置管术的效果。 方法选用Beagle犬20只,经右颈内静脉放置中心静脉管、桡动脉放置动脉测压管连接心电监护仪。采用半切开直视下切口内置管术行ECMO股动静脉插管。记录该置管方法的成功率、置管时间、出血量、术后出血并发症。 结果半切开直视下穿刺置管成功率95%,平均置管手术时间为（41±18）min,平均出血量（16±8）ml,术后切口部位出血发生率15%。 结论建立实验动物犬体外膜肺氧合模型时,采用股动静脉半切开直视下切口内穿刺置管术能快速有效地建立体外循环通路。     

Experience using the carbon dioxide laser in the removal of cutaneous tattoos

A preliminary study was undertaken to determine if the carbon dioxide laser was a suitable technique for the removal of tattoos. Twenty-eight patients with 47 tattoos had their tattoos removed by the carbon dioxide laser. The results were assessed by an independent observer 1 year after completion of treatment. The most satisfactory results were obtained in patients with discrete linear tattoos of amateur origin. In those with polychromatic blocked-in tattoos of professional origin, hypertrophic scars occurred and the overall result was unsatisfactory.