We are fortunate to live in an age in which biomedical technology has provided us with unpreceden... more We are fortunate to live in an age in which biomedical technology has provided us with unprecedented ability to supplant the functions of organs and support the physiologic processes of the human body. Ingenious doctors, physiologists, and engineers helped create these advances with new and innovative ideas. One of these pioneers was Dr. Theodor Kolobow. He is best known for one of his earliest inventions, the spiral coil membrane lung. His contributions to medical innovation, however, are diverse, as he also contributed to advances in hemodialysis, improvements in extracorporeal life support (ECLS) technology/circuit components, and through his laboratory experiments helped shape our current understanding of cardiopulmonary pathophysiology. In retrospect, much of Kolobow's work was unified by the theme of preventing iatrogenic lung injury due to mechanical ventilation. This tenet became more obvious as his later studies progressed to developing techniques and devices intended to limit ventilator pressures, and prevent bacterial colonization of the lungs. Although he formally retired from his research endeavors in 2009, the impact of his contributions remains prominent in our everyday use of techniques and equipment that he either originated or helped to develop. (Picture 1).
ASAIO journal (American Society for Artificial Internal Organs : 1992), Jan 22, 2015
An implantable pediatric artificial lung(PAL) may serve as a bridge to lung transplantation for c... more An implantable pediatric artificial lung(PAL) may serve as a bridge to lung transplantation for children with end-stagelung failure (ESLF); however, an animal model of pediatriclung failure is needed to evaluate a PAL's efficacy before it can enter clinical trials.The objective of this study was to assess ligation of the right pulmonary artery(rPA) as a model for pediatric ESLF.Seven 20-30kg lambs underwent rPA ligation andwere recovered and monitored for up to 4 days.Intraoperatively, rPA ligation significantly increased physiologic deadspace fraction (Vd/Vt: baseline=48.6 ± 5.7%, rPA ligation=60.1 ± 5.2%, p=0.012), mean pulmonary arterial pressure (mPPA:baseline=17.4 ± 2.2mmHg, rPA ligation=28.5 ± 5.2mmHg, p¼0.001), and arterial partial pressure of carbon dioxide (PaCO2: baseline=40.4 ± 9.3mmHg, rPA ligation=57.3 ± 12.7mmHg, p=0.026). Of the 7 lambs, 3 were unable to be weaned from mechanical ventilation post-operatively, 3 were successfully weaned but suffered cardiorespirato...
End-stage lung disease (ESLD) causes progressive hypercapnia, dyspnea, and impacts quality of lif... more End-stage lung disease (ESLD) causes progressive hypercapnia, dyspnea, and impacts quality of life. Many extracorporeal support (ECS) configurations for CO2 removal resolve symptoms but limit ambulation. An ovine model of pumpless ECS using subclavian vessels was developed to allow for ambulatory support.Vascular grafts were anastomosed to the left subclavian vessels in four healthy sheep. A low-resistance membrane oxygenator was attached in an arteriovenous (AV) configuration. Device function was evaluated in each animal while awake and spontaneously breathing, and while mechanically ventilated with hypercapnia induced. Sweep gas (FiO2=0.21) to the device was increased from 0-15 L/min and arterial and post-device blood gases, as well as post-device air, were sampled.Hemodynamics remained stable with average AV shunt flows of 1.34 ± 0.14 L/min.. In awake animals, CO2 removal was 3.4 ± 1.0 mL/kg/min at maximum sweep gas flow. Respiratory rate decreased from 60 ± 25 at baseline to 30 ± 11 breaths per minute. In animals with induced hypercapnia, PaCO2 increased to 73.9 ± 15.1. At maximum sweep gas flow, CO2 removal was 3.4 ± 0.4 mL/kg/min and PaCO2 decreased to 49.1 ± 6.7 mmHg.Subclavian AV access is effective in lowering PaCO2 and respiratory rate, and is potentially an effective ambulatory destination therapy for ESLD patients.
We are fortunate to live in an age in which biomedical technology has provided us with unpreceden... more We are fortunate to live in an age in which biomedical technology has provided us with unprecedented ability to supplant the functions of organs and support the physiologic processes of the human body. Ingenious doctors, physiologists, and engineers helped create these advances with new and innovative ideas. One of these pioneers was Dr. Theodor Kolobow. He is best known for one of his earliest inventions, the spiral coil membrane lung. His contributions to medical innovation, however, are diverse, as he also contributed to advances in hemodialysis, improvements in extracorporeal life support (ECLS) technology/circuit components, and through his laboratory experiments helped shape our current understanding of cardiopulmonary pathophysiology. In retrospect, much of Kolobow's work was unified by the theme of preventing iatrogenic lung injury due to mechanical ventilation. This tenet became more obvious as his later studies progressed to developing techniques and devices intended to limit ventilator pressures, and prevent bacterial colonization of the lungs. Although he formally retired from his research endeavors in 2009, the impact of his contributions remains prominent in our everyday use of techniques and equipment that he either originated or helped to develop. (Picture 1).
ASAIO journal (American Society for Artificial Internal Organs : 1992), Jan 22, 2015
An implantable pediatric artificial lung(PAL) may serve as a bridge to lung transplantation for c... more An implantable pediatric artificial lung(PAL) may serve as a bridge to lung transplantation for children with end-stagelung failure (ESLF); however, an animal model of pediatriclung failure is needed to evaluate a PAL's efficacy before it can enter clinical trials.The objective of this study was to assess ligation of the right pulmonary artery(rPA) as a model for pediatric ESLF.Seven 20-30kg lambs underwent rPA ligation andwere recovered and monitored for up to 4 days.Intraoperatively, rPA ligation significantly increased physiologic deadspace fraction (Vd/Vt: baseline=48.6 ± 5.7%, rPA ligation=60.1 ± 5.2%, p=0.012), mean pulmonary arterial pressure (mPPA:baseline=17.4 ± 2.2mmHg, rPA ligation=28.5 ± 5.2mmHg, p¼0.001), and arterial partial pressure of carbon dioxide (PaCO2: baseline=40.4 ± 9.3mmHg, rPA ligation=57.3 ± 12.7mmHg, p=0.026). Of the 7 lambs, 3 were unable to be weaned from mechanical ventilation post-operatively, 3 were successfully weaned but suffered cardiorespirato...
End-stage lung disease (ESLD) causes progressive hypercapnia, dyspnea, and impacts quality of lif... more End-stage lung disease (ESLD) causes progressive hypercapnia, dyspnea, and impacts quality of life. Many extracorporeal support (ECS) configurations for CO2 removal resolve symptoms but limit ambulation. An ovine model of pumpless ECS using subclavian vessels was developed to allow for ambulatory support.Vascular grafts were anastomosed to the left subclavian vessels in four healthy sheep. A low-resistance membrane oxygenator was attached in an arteriovenous (AV) configuration. Device function was evaluated in each animal while awake and spontaneously breathing, and while mechanically ventilated with hypercapnia induced. Sweep gas (FiO2=0.21) to the device was increased from 0-15 L/min and arterial and post-device blood gases, as well as post-device air, were sampled.Hemodynamics remained stable with average AV shunt flows of 1.34 ± 0.14 L/min.. In awake animals, CO2 removal was 3.4 ± 1.0 mL/kg/min at maximum sweep gas flow. Respiratory rate decreased from 60 ± 25 at baseline to 30 ± 11 breaths per minute. In animals with induced hypercapnia, PaCO2 increased to 73.9 ± 15.1. At maximum sweep gas flow, CO2 removal was 3.4 ± 0.4 mL/kg/min and PaCO2 decreased to 49.1 ± 6.7 mmHg.Subclavian AV access is effective in lowering PaCO2 and respiratory rate, and is potentially an effective ambulatory destination therapy for ESLD patients.
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