Flow therapy system and method
A method of determining a duration of safe apnoea. Information is obtained relating to a respiratory indicator, which can include information relating to a potential respiratory equilibrium, and a duration of safe apnoea is determined from the obtained information.
1 . A respiratory therapy system comprising:
a flow generator for providing a gases flow to a patient;
at least one processor in electronic communication with the flow generator, the at least one processor provided with instructions which, when implemented, cause the at least one processor to:
receive one or more physiological parameters associated with the patient;
calculate a predicted apnoeic respiratory equilibrium value of the patient based on the one or more physiological parameters, wherein the predicted apnoeic respiratory equilibrium value is an oxygen saturation value where an oxygen saturation of haemoglobin in the patient is predicted to be at a stable level for a period of time during apnoeic oxygen delivery to the patient; and
cause the flow generator to control the gases flow to the patient based at least in part on the predicted apnoeic respiratory equilibrium value; and
an electronic display which receives an output from the at least one processor and displays one or more properties associated with the predicted apnoeic respiratory equilibrium value.
2 . The respiratory therapy system of claim 1 , wherein the one or more properties associated with the predicted apnoeic respiratory equilibrium value include one or more of: a time to reach equilibrium, a duration of equilibrium, or a rate of decline till equilibrium.
3 . The respiratory therapy system of claim 1 , wherein the instructions, when implemented, further cause the at least one processor to: determine a duration of safe apnoea based on the predicted apnoeic respiratory equilibrium value.
4 . The respiratory therapy system of claim 1 , wherein the one or more properties associated with the predicted apnoeic respiratory equilibrium value comprise properties associated with oxygen saturation and/or carbon dioxide saturation.
5 . The respiratory therapy system of claim 1 , wherein the instructions, when implemented, further cause the at least one processor to: receive real-time patient data from one or more respiratory sensors and/or one or more physiological sensors.
6 . The respiratory therapy system of claim 5 , wherein the instructions, when implemented, further cause the at least one processor to: calculate an updated predicted apnoeic respiratory equilibrium value, cause the electronicdisplay to display one or more updated properties associated with the updated predicted apnoeic respiratory equilibrium value, determine an updated duration of safe apnoea, and/or determine one or more properties associated with an airway patency of the patient based on the real-time patient data.
7 . The respiratory therapy system of claim 1 , wherein the instructions, when implemented, further cause the at least one processor to: receive one or more safety parameters including at least one of: a threshold desaturation level or a threshold respiratory equilibrium duration.
8 . The respiratory therapy system of claim 1 , wherein the one or more physiological parameters associated with the patient comprise one or more of: a height, a weight, a neck circumference, a waist circumference, a hip to waist ratio, a body mass index (BMI), a BMI distribution, a body shape index (BSI), a body morphology indication, a lung volume, a cardiac output, an age, a pregnancy status, a difficult airway type, a medical history, disease characteristics, a treatment history, or gas flow characteristics.
9 . The respiratory therapy system of claim 1 , wherein the instructions, when implemented, further cause the at least one processor to:
determine a ventilation/perfusion (V/Q) mismatch for the patient based on the one or more physiological parameters associated with the patient; and
determine, based on the V/Q mismatch, the one or more properties associated with the predicted apnoeic respiratory equilibrium value.
10 . The respiratory therapy system of claim 9 , wherein the V/Q mismatch for the patient is determined based on a correlation of a BMI of the patient with one or more of: a neck circumference, a BSI, a hip-to-waist ratio, a monitored PaO 2 , or a blood gas concentration of the patient.
11 . The respiratory therapy system of claim 1 , wherein the instructions, when implemented, further cause the at least one processor to: compare or fit a model to the one or more physiological parameters associated with the patient to determine the one or more properties associated with the predicted apnoeic respiratory equilibrium value.
12 . The respiratory therapy system of claim 1 , wherein the instructions, when implemented, further cause the at least one processor to:
determine the one or more properties associated with the predicted apnoeic respiratory equilibrium value using a first parameter of the one or more physiological parameters associated with the patient; and
calculate a duration of safe apnoea of the patient using a second parameter of the one or more physiological parameters associated with the patient.
13 . The respiratory therapy system of claim 12 , wherein the first parameter comprises: a BMI, a PaO 2 , a blood gas concentration, or a cardiac output of the patient, and wherein the second parameter comprises: the PaO 2 or the blood gas concentration of the patient.
14 . The respiratory therapy system of claim 1 , wherein the one or more properties associated with the predicted apnoeic respiratory equilibrium value are determined based on one or more of: a ratio of a PaO 2 and a BMI of the patient, a ratio of a blood gas concentration and the BMI of the patient, or a ratio of a cardiac output and the BMI of the patient.
15 . The respiratory therapy system of claim 1 , wherein the instructions, when implemented, further cause the at least one processor to:
calculate a ratio of measured PaO 2 , blood gas concentration, or cardiac output of the patient to a BMI of the patient; and
compare or fit a model to the ratio to determine the one or more properties associated with the predicted apnoeic respiratory equilibrium value.
16 . The respiratory therapy system of claim 1 , wherein the instructions, when implemented, further cause the at least one processor to:
determine that the patient is atypical based on the one or more physiological parameters associated with the patient; and
determine the one or more properties associated with the predicted apnoeic respiratory equilibrium value based on the atypical determination.
17 . The respiratory therapy system of claim 1 , wherein the predicted apnoeic respiratory equilibrium value is above or below a threshold desaturation level for the patient.
18 . The respiratory therapy system of claim 1 , wherein the stable level is when the oxygen saturation of haemoglobin in the patient has a rate of binding that is equal to a rate of release.
19 . The respiratory therapy system of claim 1 , wherein causing the flow generator to control the gases flow to the patient based at least in part on the predicted apnoeic respiratory equilibrium value, is based on receiving user input from a user via the electronic display.
20 . The respiratory therapy system of claim 1 , wherein the respiratory therapy system uses the predicted apnoeic respiratory equilibrium value as feedback to automatically control the gases flow to the patient.
21 . The respiratory therapy system of claim 1 , wherein causing the flow generator to control the gases flow to the patient based at least in part on the predicted apnoeic respiratory equilibrium value includes comparing the predicted apnoeic respiratory equilibrium value to a target value, and increasing a flow rate of the gases flow based on determining that the predicted apnoeic respiratory equilibrium value is lower than the target value.