A system for determining a potential lung recruitment value for a patient, the system comprising: an electrical impedance tomography device; at least one processor; and at least one non-transitory computer readable storage medium storing instructions thereon that, when executed by the at least one processor, cause the at least one processor to: - in response to a sequence of positive end expiratory pressures being applied to a patient, cause an end expiratory lung impedance to be measured by the electrical impedance tomography device at each positive end expiratory pressure of the sequence of positive end expiratory pressures; - determine a first index representing a change in end expiratory lung impedance between a first end expiratory lung volume of the sequence of positive end expiratory pressures and a second, subsequent end expiratory lung volume of the sequence of positive end expiratory pressures; - determine a second index representing a change in chord-compliance of the lungs of the patient between the first end expiratory lung volume and the second, subsequent end expiratory lung volume; and - based on the first index and the second index, determine a potential lung recruitment value for the patient. an electrical impedance tomography device; at least one processor; and at least one non-transitory computer readable storage medium storing instructions thereon that, when executed by the at least one processor, cause the at least one processor to: - in response to a sequence of positive end expiratory pressures being applied to a patient, cause an end expiratory lung impedance to be measured by the electrical impedance tomography device at each positive end expiratory pressure of the sequence of positive end expiratory pressures; - determine a first index representing a change in end expiratory lung impedance between a first end expiratory lung volume of the sequence of positive end expiratory pressures and a second, subsequent end expiratory lung volume of the sequence of positive end expiratory pressures; - determine a second index representing a change in chord-compliance of the lungs of the patient between the first end expiratory lung volume and the second, subsequent end expiratory lung volume; and - based on the first index and the second index, determine a potential lung recruitment value for the patient. - in response to a sequence of positive end expiratory pressures being applied to a patient, cause an end expiratory lung impedance to be measured by the electrical impedance tomography device at each positive end expiratory pressure of the sequence of positive end expiratory pressures; - determine a first index representing a change in end expiratory lung impedance between a first end expiratory lung volume of the sequence of positive end expiratory pressures and a second, subsequent end expiratory lung volume of the sequence of positive end expiratory pressures; - determine a second index representing a change in chord-compliance of the lungs of the patient between the first end expiratory lung volume and the second, subsequent end expiratory lung volume; and - based on the first index and the second index, determine a potential lung recruitment value for the patient. - determine a second index representing a change in chord-compliance of the lungs of the patient between the first end expiratory lung volume and the second, subsequent end expiratory lung volume; and - based on the first index and the second index, determine a potential lung recruitment value for the patient.