Cannula For Minimizing Dilution Of Dosing During Nitric Oxide Delivery

Abstract

Described are nasal cannulas that improve the precision of the delivered dose for nitric oxide therapy by reducing the dilution of nitric oxide. The nasal cannulas may reduce the total volume and potential for retrograde flow during nitric oxide therapy through the design of the specific dimensions of the flow path and/or having check valves in the nitric oxide delivery line and/or having a flapper or umbrella valve dedicated to nitric oxide delivery. The nasal cannulas may also use materials that limit oxygen diffusion through the cannula walls. The nosepiece for these cannulas may be manufactured by a molding technique.

1 .- 20 . (canceled) 
     
     
         21 . A method of administering nitric oxide for treating pulmonary hypertension, the method comprising:
 administering a pulse of a gas comprising nitric oxide to a patient in need thereof, wherein the pulse is administered through a nasal cannula comprising a cannula nosepiece comprising a nitric oxide flow path having a volume that is less than 50% of a volume of pulse of the gas comprising nitric oxide.   
     
     
         22 . The method of  claim 21 , wherein the nasal cannula comprises:
 a first lumen, a second lumen, and a third lumen:
 the first lumen being a first therapeutic gas lumen for delivering the gas comprising nitric oxide to the patient, 
 the second lumen being a triggering lumen, and 
 the third lumen being a second therapeutic gas lumen for delivering a gas comprising oxygen to the patient; and 
   wherein the cannula nosepiece has separate flow paths to the patient for each of (i) the first therapeutic gas lumen, (ii) the triggering lumen, and (iii) the second therapeutic gas lumen.   
     
     
         23 . The method of  claim 21 , wherein the nasal cannula comprises a first lumen for delivering the gas comprising nitric oxide to the patient and a second lumen, wherein the first lumen has a smaller inner diameter than an inner diameter of the second lumen. 
     
     
         24 . The method of  claim 21 , wherein the pulse of gas comprising nitric oxide has a volume less than 1 mL. 
     
     
         25 . The method of  claim 21 , wherein the nitric oxide flow path is less than 40% of the volume of pulse of the gas comprising nitric oxide. 
     
     
         26 . The method of  claim 21 , wherein the nitric oxide flow path has a volume less than or equal to 0.035 mL. 
     
     
         27 . The method of  claim 21 , wherein the nasal cannula at least one of inhibits mixing of nitric oxide and oxygen in the cannula nosepiece and reduces delivery of nitrogen dioxide to the patient. 
     
     
         28 . A method of administering nitric oxide for treating pulmonary hypertension, the method comprising:
 administering a plurality of pulses of a gas comprising nitric oxide to a patient in need thereof, wherein the plurality of pulses is administered through a nasal cannula comprising a cannula nosepiece comprising a nitric oxide flow path having a volume that is less than 50% of a volume of each of the plurality of pulses of the gas comprising nitric oxide.   
     
     
         29 . The method of  claim 28 , wherein the nasal cannula comprises:
 a first lumen, a second lumen, and a third lumen:
 the first lumen being a first therapeutic gas lumen for delivering a gas comprising nitric oxide to the patient, 
 the second lumen being a triggering lumen, and 
 the third lumen being a second therapeutic gas lumen for delivering a gas comprising oxygen to the patient; and 
   wherein the cannula nosepiece has separate flow paths to the patient for each of (i) the first therapeutic gas lumen, (ii) the triggering lumen, and (iii) the second therapeutic gas lumen.   
     
     
         30 . The method of  claim 28 , wherein the nasal cannula comprises a first lumen for delivering the gas comprising nitric oxide to the patient and a second lumen, wherein the first lumen has a smaller inner diameter than an inner diameter of the second lumen. 
     
     
         31 . The method of  claim 28 , wherein each of the plurality of pulses of the gas comprising nitric oxide has a volume less than 1 mL. 
     
     
         32 . The method of  claim 28 , wherein the nitric oxide flow path is less than 40% of the volume of each of the plurality of pulses of the gas comprising nitric oxide. 
     
     
         33 . The method of  claim 28 , wherein the nitric oxide flow path has a volume less than or equal to 0.035 mL. 
     
     
         34 . The method of  claim 28 , wherein the nasal cannula at least one of inhibits mixing of nitric oxide and oxygen in the cannula nosepiece and reduces delivery of nitrogen dioxide to the patient. 
     
     
         35 . A method of administering nitric oxide to a patient, the method comprising:
 administering a plurality of pulses of a gas comprising nitric oxide to the patient, wherein the plurality of pulses is administered through a nasal cannula comprising a cannula nosepiece comprising a nitric oxide flow path having a volume that is less than 50% of a volume of each of the plurality of pulses of the gas comprising nitric oxide.   
     
     
         36 . The method of  claim 35 , wherein the nasal cannula comprises:
 a first lumen, a second lumen, and a third lumen:
 the first lumen being a first therapeutic gas lumen for delivering a gas comprising nitric oxide to the patient, 
 the second lumen being a triggering lumen, and 
 the third lumen being a second therapeutic gas lumen for delivering a gas comprising oxygen to the patient; and 
   wherein the cannula nosepiece has separate flow paths to the patient for each of (i) the first therapeutic gas lumen, (ii) the triggering lumen, and (iii) the second therapeutic gas lumen.   
     
     
         37 . The method of  claim 35 , wherein the nasal cannula comprises a first lumen for delivering the gas comprising nitric oxide to the patient and a second lumen, wherein the first lumen has a smaller inner diameter than an inner diameter of the second lumen. 
     
     
         38 . The method of  claim 35 , wherein each of the plurality of pulses of the gas comprising nitric oxide has a volume less than 1 mL. 
     
     
         39 . The method of  claim 35 , wherein the nitric oxide flow path is less than 40% of the volume of each of the plurality of pulses of the gas comprising nitric oxide. 
     
     
         40 . The method of  claim 35 , wherein the nasal cannula at least one of inhibits mixing of nitric oxide and oxygen in the cannula nosepiece and reduces delivery of nitrogen dioxide to the patient.