Catheters parenteral

Parenteral drug administration means the giving of a drug by the subcutaneous (SC), intramuscular (IM), intravenous (IV), or intradermal route (Fig. 2-5). Other routes of parenteral administration that may be used by the primary care provider are intralesional (into a lesion), intra-arterial (into an artery), intracardiac (into the heart), and intra-articular (into a joint), hi some instances, intra-arterial dragp are administered by a nurse. However, administration is not by direct arterial injection but by means of a catheter that has been placed in an artery. 

TPN may be administered through a peripheral vein or through a central venous catheter. Peripheral TPN is used for patients requiring parenteral nutrition for relatively short periods of time (no more than 5-14 days) and when the central venous route is not possible or necessary. Peripheral TPN is used when the patient s caloric needs are minimal and can be partially met by normal... 

Parenteral nutrition can be a lifesaving therapy in patients with intestinal failure, but the oral or enteral route is preferred when providing nutrition support ( when the gut works, use it ). Compared with PN, enteral nutrition generally is associated with fewer infectious complications (e.g., pneumonia, intraabdominal abscess, and catheter-related infections) and potentially improved outcomes.1-3 However, if used in appropriate patients (i.e., patients with questionable intestinal function or when the intestine cannot be used), PN can be used safely and effectively and may improve nutrient delivery.4 Indications for PN are listed in Table 97-1.1... 

In 1978, on the basis of a few measurements of urine calcium and phosphate excretion as well as an awareness of the previously mentioned work regarding the amounts of calcium and phosphate normally accreted in utero and postnatally, it became apparent that the demineralization, fractures and rickets we were seeing in our infants were caused by calcium deficiency. Consequently we increased the amount of calcium added to the parenteral alimentation solutions. If more than 12.5 mM of the calcium were added to a liter of hyperalimentation solution, gross precipitation would occur in the feeding solution. If 10 mM of calcium were added per liter, crystalline precipitated began to build up on the inside of our barium-impregnated silicone rubber central venous catheters. This crystalline precipitate resulted in gradual occlusion and functional loss of these lines. After several false starts and six lost catheters, chemical and crystal analysis showed that the precipitate inside these catheters was CaHPO. ... 

Almost 30 routes exist for administration of drugs to patients, but only a handfbl of these are commonly used in preclinical safety studies (Gad, 1994). The most common deviation from what is to be done in clinical trials is the use of parenteral (injected) routes such as IV (intravenous) and SC (subcutaneous) deliveries. Such injections are loosely characterized as bolus (all at once or over a very short period, such as five minutes) and infusion (over a protracted period of hours, days, or even months). The term continuous infusion implies a steady rate over a protracted period, requiring some form of setup such as an implanted venous catheter or infusion port. 

Sodium chloride (normal saline)- 0.9% Sodium chloride (normal saline), which is isotonic, restores both water and sodium chloride losses. Other indications for parenteral 0.9% saline include Diluting or dissolving drugs for IV, IM, or subcutaneous injection flushing of IV catheters extracellular fluid replacement treatment of metabolic alkalosis in the presence of fluid loss and mild sodium depletion as a priming solution in hemodialysis procedures and to initiate and terminate blood transfusions without hemolyzing red blood cells. 

If tuberculin syringes are used to measure very small doses, one must be aware of the problem of inadvertent overadministration of digoxin. Do not flush the syringe with the parenteral solution after its contents are expelled into an indwelling vascular catheter. 

Parenteral 50, 100 mg lyophilized powder to reconstitute for IV injection 2 mg for catheter clots Aminocaproic acid (generic, Amicar)... 

Besides local toxicity, discussed above, there are numerous other modes of potential adverse interactions involving excipients (19,20). Many of these pose little threat provided the amounts of excipients are constrained to certain levels. Excessive amounts, however, can cause problems, particularly for patients who are intolerant of even modest levels. Commonly used phosphate buffers may cause calcium loss with formation of insoluble calcium phosphates when such buffers are administered in over-ambitious amounts (21). Calcium phosphate precipitation has been noted particularly in nutritional parenteral admixtures for neonates because of the high nutrient requirements. Similarly, renal toxicity has been associated with depletion of zinc and other trace metals caused by large parenteral doses of ethylenediaminete-traacetic acid (EDTA) (22). Excessive absorption of glycine solutions, when used as irrigants during transurethral resections, can cause hyponatremia, hypertension, and confusion (23). The use of preservatives has been associated with cardiac effects in a few patients (24). Premature neonates were found to be at risk for receiving toxic amounts of benzoic acid or benzyl alcohol in bacteriostatic solutions used to flush intravenous catheters (25). 

For short-term feeding (less than 14 days) NICE (2006) recommends parenteral feeding via a peripheral venous catheter for those patients who do not need central access. A GTN patch can be applied above the peripheral venous catheter site to promote vasodilatation of the vein for those patients who have narrow veins. Some TPN is unsuitable for peripheral administration due to the nitrogen and glucose concentration these must go through a central venous catheter. 

Chelation can be effectively carried out only by slow parenteral administration of desferrioxamine s.c. or i.v. through an indwelling catheter with a small portable syringe pump e.g. over 9-12 h... 

Xu QA, Zhang Y, Trissel LA, Gilbert DL. Adequacy of a new chlorhexidine-bearing polyurethane central venous catheter for administration of 82 selected parenteral drugs. Ann Pharmacother 2000 34(10) 1109-16. 

Totally implantable venous devices are being increasingly used in patients who require long-term continuous parenteral drug therapy, especially in cancer chemotherapy. Inevitably there have been complications, including catheter fracture, as a consequence of pinched-off syndrome (6). 

Migration of a catheter caused failure of parenteral nutrition in a baby (8). 

The authors speculated that the catheter tip had spontaneously migrated because the ulcer on the left shoulder had eroded deeply to form a venocutaneous fistula with the left cephaUc vein. Continuous leakage of parenteral nutrition fluid through the fistula was soaked up by the gauze pads used to cover the ulcer, preventing early recognition of the problem. 

A major complication of intravenous infusion is thrombophlebitis, which is a principle limitation of peripheral parenteral nutrition. Its precise pathogenesis is unclear, but venospasm has been proposed as the most likely cause. However, in a study with ultrasound techniques to monitor vein caliber, there was no evidence to support this hypothesis, although thrombophlebitis was observed (10). The author suggested that the initiating event may be venous endothelial trauma, caused by the venepuncture itself, abrasion at the catheter tip, or the delivery of the feeding solution. 

Umbilical venous catheters are commonly used in neonatal care for drug administration and parenteral nutrition. However, many risks are associated with their use. Ascites associated with parenteral nutrition have been reported (19). 

In a study of catheter infection in patients treated with total parenteral nutrition a distant septic focus was present in 165 of 244 patients (188 of 269 catheters 70%). There was a colonization rate of 19% of the catheters of the patients with a distant septic focus, compared with 7.4% in patients without a distant septic focus. There was a high mortahty rate in patients with a distant septic focus and a colonized catheter sepsis was responsible for 33 of the 48 deaths (69%) in this group (33). 

Catheter infections in recipients of parenteral nutrition are of particular concern in children and can result in line removal, deep vein thrombosis, or an increased risk of hver disease. The incidence of catheter-related infections in 47 children receiving long-term parenteral nutrition has been studied retrospectively, one goal being to identify potential risk factors (35). The children had 125 catheters and 207 catheter-years. The average infection rate was 2.1/1000 parenteral nutrition days. The only factor identified was that early onset of infection after starting parenteral nutrition appeared to predict a poor prognosis. 

HIV-positive subjects are expected to be at even greater risk of line-related infection. A prospective study of 212 subjects with HIV infection with 327 central venous catheters has provided evidence of this enhanced risk (36). Over the period 1994-97, 33% were suspected as being infected, although only 61 episodes were diagnosed as catheter-related sepsis. Three variables affected the rate of sepsis parenteral nutrition, low numbers of circulating CD+ cells, and a high Apache score. 

Panetta J, Morley C, Betheras R. Ascites in a premature baby due to parenteral nutrition from an umbihcal venous catheter. J Paediatr Child Health 2000 36(2) 197-8. 

Cahill SL, Benotti PN. Catheter infection control in parenteral nutrition. Nutr Chn Pract 1991 6(2) 65-7. 

Chuang JH, Chuang SF. Imphcation of a distant septic focus in parenteral nutrition catheter colonization. J Parenter Enteral Nutr 1991 15(2) 173-5. 

Beau P, Matrat S. A comparative study of polyurethane and silicone cuffed-catheters in long-term home total parenteral nutrition patients. Clin Nutr 1999 18(3) 175-7. 

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