Insertion system and methods for nasogastric tubes

Abstract

A nasogastric tube insertion system comprises a nasogastric tube, a guide element, and an inserter element. The inserter element has a slim, elongate main body, a handle attached to the body, and an anatomically curved insertion section. The guide element comprises a swallowable weight attached to a cord, string, monofilament line, tube, or other similar line. The swallowable weight may be ablative in the presence of stomach fluids or may be deflated to allow the guide element to be removed while the nasogastric tube remains in place. The inserter element is inserted through the patient's nasal passages and optionally into the oropharynx. The weight is released and the patient swallows it into the stomach. The guide element is threaded through the guide element retaining structure, and the nasogastric tube is safely inserted along the guide element into the patient's stomach. Chemical property indicators sensitive to fluids found in the stomach may be provided in the nasogastric tube or the guide element to verify correct placement of the nasogastric tube in the stomach.

1 - 3 . (canceled) 
     
     
         4 . A guide element for insertion into a patient's stomach, the guide element comprising:
 a thin elongate element having a first end and a second end; and   a swallowable weight affixed to said first end and adapted to ablate within a short period after the weight is inserted into the patient's stomach.   
     
     
         5 . The guide element of  claim 4  wherein said swallowable weight is adapted to ablate by dissolving in the presence of stomach fluids. 
     
     
         6 . The guide element of  claim 4  wherein said swallowable weight is adapted to ablate by disintegrating in the presence of stomach fluids. 
     
     
         7 . The guide element of  claim 4  wherein said elongate element further comprises attachment structures extending from the element to secure the weight to the element. 
     
     
         8 . The guide element of  claim 4  wherein
 said thin elongate element is adapted for slidable movement within a retaining structure of a nasogastric tube. 
 
     
     
         9 . The guide element of  claim 8  wherein:
 said thin elongate element is further adapted to allow slidable movement of said first end thereof through said retaining structure of said nasogastric tube after said weight has ablated. 
 
     
     
         10 . The guide element of  claim 8  wherein said retaining structure is a lumen extending most of the length of the nasogastric tube, and said thin elongate element is further adapted to allow slidable movement of said first end thereof through said retaining structure of said nasogastric tube after said weight has ablated. 
     
     
         11 . (canceled) 
     
     
         12 . A nasogastric tube comprising:
 an elongate tube body having a distal end and a proximal end;   at least one lumen extending substantially from said distal end to said proximal end;   an opening in said tube body near said distal end allowing fluid communication from said lumen to space exterior of the tube body; and   a chemical-property indicating medium on said adapted to receive fluid from said lumen provide a visual indication of a sensed chemical property.   
     
     
         13 . The nasogastric tube of  claim 12  wherein said chemical-property indicating medium is adapted to provide a visual indication when pH of said fluid is below a predefined threshold. 
     
     
         14 . The nasogastric tube of  claim 12  wherein said chemical-property indicating medium is adapted to provide a visual indication when pH of said fluid is below about 5.0. 
     
     
         15 . The nasogastric tube of  claim 12  wherein said chemical property indicating medium includes phenolphthalein. 
     
     
         16 . The nasogastric tube of  claim 12  wherein said chemical property indicating medium comprises litmus. 
     
     
         17 . The nasogastric tube of  claim 12  wherein said chemical property indicating medium comprises a substrate bearing a pH indicator and said nasogastric tube further comprises a channel in fluid communication with said lumen for capturing said substrate. 
     
     
         18 . The nasogastric tube of  claim 12  wherein said chemical property indicating medium comprises a coating applied to an interior surface of said lumen. 
     
     
         19 . The nasogastric tube of  claim 12  wherein said chemical property indicating medium comprises a pH-indicator-bearing coating applied to an interior surface of said lumen. 
     
     
         20 . A method for inserting a nasogastric tube in a patient comprising the steps of:
 a. using an inserter element to aid in placing an end of a guide element into the patient's oropharynx;   b. releasing the end of the guide element from the inserter element;   c. causing the patient to swallow the guide element into the patient's stomach; and   d. inserting the nasogastric tube along the guide element into the patient's stomach; and   e. withdrawing the guide element from the patient while the nasogastric tube remains in the patient's stomach.   
     
     
         21 . The method of  claim 20  wherein step e. thereof further comprises:
 e1. changing the shape of said guide element to allow the leading end of the guide element to pass through a retaining structure of the nasogastric tube. 
 
     
     
         22 . The method of  claim 21  wherein step e1. thereof further comprises:
 e1a. deflating a swallowable weight component of said guide element. 
 
     
     
         23 . The method of  claim 21  wherein step e1. thereof further comprises:
 e1a. ablating a swallowable weight component of said guide element by exposing it to stomach fluids. 
 
     
     
         24 . The method of  claim 23  wherein step e1a. thereof further comprises:
 e1a. dissolving the swallowable weight component of said guide element by exposing it to stomach fluids. 
 
     
     
         25 - 28 . (canceled)