Feeding tubes

Fig. 5. Separation in Latham bowl (a) whole blood is pumped down the feed tube and enters bowl at bottom (b) centrifugal force spins denser cellular components outside, leaving plasma or platelet-rich plasma (PRP) in inner band (c) when bowl is full, plasma flows out effluent tube, followed by platelets and then leukocytes, until bowl is almost completely full of ted cells (d) after draw is completed, bowl stops spinning and uncoUected components are...

Fig. 13. A hoUow-fibet reverse osmosis membrane element. Courtesy of DuPont Permasep. In this twin design, the feedwater is fed under pressure into a central distributor tube where half the water is forced out tadiaUy through the first, ie, left-hand, fiber bundle and thus desalted. The remaining portion of the feedwater flows through the interconnector to an annular feed tube of the second, ie, right-hand, fiber bundle. As in the first bundle, the pressurized feedwater is forced out tadiaUy and desalted. The product water flows through the hoUow fibers, coUects at each end of the element, and exits there. The concentrated brine from both bundles flows through the concentric tube in the center of the second bundle and exits the element on the right.

An aerosol container can be considered a special appHcation of airless atomization (see Aerosols). The pressure is usually suppHed by a Hquefied gas in the container at its equiUbrium pressure. The material being sprayed has a very low viscosity to provide easy material flow through the feed tube and to permit fine atomization. 

The product withdrawal pipe is located in the annulus halfway up the draft tube where the vector of the circulation velocity of the suspension and that of the withdrawal velocity of the product point in the same direction. Using this arrangement ensures low particle classification effects. Furthermore, the feed tubes and withdrawal tube can be exactly positioned in the reactor and scaled... 

In operation, the centrifuge tube is filled with the sedimentation liq to within 10mm of the top. The feed-tube is then filled with the sample suspension and the upper end is closed by the operator s finger. The feed-tube is then placed in the centrifuge tube with the suspension in contact with the column of clear sedimentation liq this starts the sedimentation. The finger is then removed... 

The impinging-jet micro mixers are constructed as a cylindrical block comprising two feed tubes which become smaller towards the outlet [48]. Accordingly, the main characteristics of these mixers are the diameter of the outlet bore, the interspaces between the bores and the angle defined by the orientation of bores (relative to the normal). For one experimental study [48], nine impinging jet micro mixers were made which differ in these specifications. 

Presence of a transpyloric feeding tube 0 H2-receptor antagonist or PPI... 

Flush feeding tube with 30 mL water or saline... 

Positioning the tip of the feeding tube past the ligament of Treitz may be more effective than postpyloric placement in high-risk patients... 

Compatibility of medications with an enteral nutrition (EN) formula and, conversely, an enteral nutrition (EN) formula with administered medications is of concern when administering medications through feeding tubes. 

Diarrhea Drug related Antibiotic-induced bacterial overgrowth Hyperosmolar medications administered via feeding tubes Antacids containing magnesium Malabsorption Hypoalbuminemia/gut mucosal atrophy Pancreatic insufficiency Inadequate GIT surface area Rapid GIT transit Radiation enteritis Tube feeding related Rapid formula administration Formula hyperosmolalty Low residue (fiber) content Lactose intolerance Bacterial contamination... 

Occluded feeding tube lumen Insoluble complexation of enteral formula and medication(s) Inadequate flushing of feeding tube Undissolved feeding formula... 

Gastroparesis/atony causing regurgitation Feeding tube malpositioned Compromised lower esophageal sphincter Diminished gag reflex... 

Endoscopic and surgical feeding tubes can be complicated by erosion of the exit site caused by leakage of gastric or intestinal contents onto the skin. This complication must be... 

Medications available commercially as compressed tablets can be crushed for administration through feeding tubes. After such a tablet is crushed into a fine powder, it should be mixed with 10 to 30 mL of fluid (usually warm water) for... 

If a liquid dosage form of a medication exists, it would seem rational to use this dosage form for administration through a feeding tube. Although such a decision may decrease the potential for tube clogging, it may in some instances decrease tolerability of the medication administration. Sorbitol is an excipient found in many liquid medications in amounts sufficient to cause diarrhea. If diarrhea secondary to sorbitol in a liquid medication is suspected in a patient on EN, contact with the manufacturer to ascertain sorbitol content may be necessary. 

The location of the tip of the feeding tube is important when considering medication administration down a feeding tube. This is particularly true if the medication acts locally in the GI tract itself. For example, sucralfate and antacids act locally in the stomach. Therefore, administration of these medications through a duodenal or jejunal tube is not logical. Likewise, for medications such as itraconazole that require acid for best absorption, administration directly into the duodenum or jejunum would be expected to result in suboptimal absorption. Absorption of drugs when administered directly into the small bowel, especially the jejunum, rather than into the stomach is another area where more research would be useful. 

Enteral nutrition Delivery of nutrients via the gastrointestinal tract, either by mouth or by feeding tube. 

Gastrostomy Operative placement of a new opening into the stomach, usually associated with feeding tube placement. 

Percutaneous endoscopic gastrostomy Gastric feeding tube placed via endoscopic technique. 

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