Abstract: A multilumen unilimb breathing circuit with a detachable proximal fitting for providing respiratory gases to and receiving expiratory gases from a patient. The circuit has unique fittings for connection to patient devices or assisted ventilation systems and components. Despite many teachings away in the prior art from making breathing circuit tubing detachable from the proximal terminal, the proximal end of the rigid multilumen proximal fitting can be attached and detached by a user at a site of use to a mating multilumen proximal terminal while its distal end can be attached to multiple lumens formed of flexible tubing for carrying gases to and from a patient. The present invention introduces for the first time to the multilumen unilimb circuit art a detachable proximal fitting.

Abstract: A multilumen filter device has a housing with first and second filter chambers, each chamber in fluid communication with a separate distal and proximal fluid path. The filter device may be used to provide respiratory gases to and receive expiratory gases from a patient connected to a unilimb respiratory circuit. The filter device may also serve as a connector for respiratory circuit components, and have fasteners or blocking devices at either or both of its distal and proximal ends.

Abstract: A method for providing assisted ventilation which avoids hypoxia and hypocapnia in which a predetermined dead space in an assisted ventilation system is provided external to the patient. The method may also be used to create normocapnia or moderate hypercapnia without causing hypoxia during assisted ventilation. Improved assisted ventilation devices, including an improved proximal terminal, improved tubular attachments and improved coaxial filters, are disclosed which are safer and less expensive to use than corresponding prior art unilimb assisted ventilation devices. Connector fittings and adapters to provide connector fittings on assisted ventilation devices are disclosed which provide positive indication of attachment of assisted ventilation devices and resist detachment of assisted ventilation devices. The devices of the present invention also reduce medical waste in comparison to prior art assisted ventilation devices.

Abstract: A method for providing assisted ventilation which avoids hypoxia and hypocapnia is disclosed, in which a predetermined dead space in an assisted ventilation system is provided external to the patient. The method may also be used to create normocapnia or moderate hypercapnia without causing hypoxia during assisted ventilation. Preferably, hypoxia can be avoided while inducing and/or maintaining the arterial carbon dioxide tension between about 35 and 95 mmHg. Dead space volumes as small as 10 ml and exceeding 150 ml are utilized in the method. An improved proximal terminal, tubular attachments, and coaxial filter are disclosed, which are safer the less expensive to use than prior art unilimb assisted ventilation systems; the devices of the present invention also reduce medical wastes in comparison to prior art assisted ventilation systems.

Abstract: A method for providing assisted ventilation which avoids hypoxia and hypocapnia is disclosed, in which a predetermined dead space in an assisted ventilation system is provided external to the patient. The method may also be used to create normocapnia or moderate hypercapnia without causing hypoxia during assisted ventilation. Preferably, hypoxia can be avoided while inducing and/or maintaining the arterial carbon dioxide tension between about 35 and 95 mmHg. Dead space volumes as small as 10 ml and exceeding 150 ml are utilized in the method. An improved proximal terminal, tubular attachments, and coaxial filter are disclosed, which are safer and less expensive to use than prior art unilimb assisted ventilation systems; the devices of the present invention also reduce medical wastes in comparison to prior art assisted ventilation systems.