Systems and methods for ex vivo lung care

A system for evaluating a lung comprising:

• a first valve configured to be coupled to a gas source;
• a gas exchanger coupled to the first valve;
• an ex vivo perfusion circuit for circulating a perfusion fluid through the lung, the fluid entering the lung through a pulmonary artery interface and leaving the lung through a left atrial interface;
• a ventilation circuit for flowing a ventilation gas into and out of the lung through a tracheal interface, the ventilation circuit adapted to flow a captive volume of a ventilation gas back and forth between the lung and a variable volume chamber;
• and
• a trickle valve in fluid communication with the ventilation circuit configured to introduce into the captive volume an additional volume of the ventilation gas, wherein the additional volume of the ventilation gas is about 10% of a tidal volume,
• wherein the system is configured to deoxygenate the perfusion fluid until a predetermined first value of oxygen content in the perfusion fluid is reached;
• wherein the system is configured to hold the perfusion fluid at the predetermined first value of oxygen content when the first valve is closed;
• wherein the system is configured to halt ventilation or initiate a purge cycle when the first valve is closed and the perfusion fluid is held at the predetermined value of oxygen content;
• wherein the system is configured to reoxygenate the perfusion fluid by ventilating the lung with an oxygenation gas until a predetermined second value of oxygen content in the perfusion fluid is reached, and
• wherein the system is further configured to determine a condition of the lung based on a time taken for the lung to cause the oxygen content in the perfusion fluid to change from the first value of oxygen content to the second value of oxygen content.

A system for evaluating a lung comprising:

• a first valve means configured to be coupled to a gas source;
• a gas exchanger means coupled to the first valve means;
• means for circulating a perfusion fluid through the lung, the fluid entering the lung through a pulmonary artery interface and leaving the lung through a left atrial interface;
• means for flowing a ventilation gas into and out of the lung through a tracheal interface;
• a ventilation circuit adapted to flow a captive volume of a ventilation gas back and forth between the lung and a variable volume chamber;
• and
• means for introducing into the captive volume an additional volume of the ventilation gas
• wherein the additional volume of the ventilation gas is about 10% of a tidal volume,
• wherein the system is configured to deoxygenate the perfusion fluid using the gas exchanger means when the first valve means is open until a predetermined first value of oxygen content in the perfusion fluid is reached,
• to hold the perfusion fluid at the predetermined first value of oxygen content when the first valve means is closed, to halt ventilation or initiate a purge cycle when the first valve means is closed and the perfusion fluid is held at the predetermined value of oxygen content,
• and to reoxygenate the perfusion fluid by ventilating the lung with an oxygenation gas until a predetermined second value of oxygen content in the perfusion fluid is reached, and wherein the system is further configured to determine a condition of the lung based on a time taken for the lung to cause the oxygen content in the perfusion fluid to change from the first value of oxygen content to the second value of oxygen content.

A lung care system comprising:

• a first valve configured to be coupled to a gas source;
• a gas exchanger coupled to the first valve;
• an ex vivo perfusion circuit for circulating a perfusion fluid through the lung, the fluid entering the lung through a pulmonary artery interface and leaving the lung through a left atrial interface;
• a ventilation circuit for flowing a ventilation gas into and out of the lung through a tracheal interface, the ventilation circuit adapted to flow a captive volume of a ventilation gas back and forth between the lung and a variable volume chamber;
• and
• a trickle valve in fluid communication with the ventilation circuit for introducing into the captive volume an additional volume of the ventilation gas, wherein the additional volume of the ventilation gas is about 10% of a tidal volume,
• wherein the system includes a lung maintenance mode and a lung evaluation mode,
• the lung maintenance mode being configured to ventilate the lung through the tracheal interface by flowing the captive volume of the ventilation gas back and forth between the lung and the variable volume chamber, and the evaluation mode being configured to:
• deoxygenate the perfusion fluid using the gas exchanger when the first valve is open until a predetermined first value of oxygen content in the perfusion fluid is reached;
• hold the perfusion fluid at the predetermined first value of oxygen content when the first valve is closed;
• halt ventilation or initiate a purge cycle when the first valve is closed and the perfusion fluid is held at the predetermined value of oxygen content;
• and
• reoxygenate the perfusion fluid by ventilating the lung with an oxygenation gas until a predetermined second value of oxygen content in the perfusion fluid is reached;
• and
• determine a condition of the lung based on a time taken for the lung to cause the oxygen content in the perfusion fluid to change from the first value of oxygen content to the second value of oxygen content.