Enteral Versus Parenteral Feeding

With the advent of the technique of PN by a large central vein in the late 1960s, this modality of feeding quickly became popular. PN was used originally in patients with-inflammatory bowel disease (IBD) or congenital bowel abnormalities but was incorporated quickly into care of other types of patients such as the critically ill. The relative ease of PN administration, along with the perception that critically ill patients had prolonged high-energy expenditures, led to complications of overfeeding. In the United States, where no IV fat emulsion was available commercially for several years during the 1970s, the impact of dextrose overfeeding was observed. Complications included hyperglycemia, carbon dioxide overproduction leading to delays in weaning from mechanical ventilation, and liver abnormalities owing to hepatic steatosis.

Table 101-2 Potential Indications for EN

Neoplastic Disease

GI Disease

Chemotherapy

IBD

Radiationtherapy

Short bowel syndrome

Upper Gl tumors

Esophageal motility disorder

Cancer cachexia

Pancreatitis

Organ Failure

Fistulas

Hepatic

Gastroesophageal reflux disease

Renal

Esophageal atresia

Cardiac cachexia

Neurologic Impairment

Pulmonary

Comal ose state

Bronchopulmonary dysplasia

Cerebrovascular accident

Congenital heart disease

Demyelinating disease

Hypermetabcillc States

Severe depress ion

Closet J head Injury

Failure to thrive

Burns

Cerebral palsy

Trauma

Other Indications

Postoperative major surgery

AIDS

Sepsis

Anorexia nervosa

Complications dui ng pregnancy

Geriatric patients with multiple

chronic disease

Organ transplantation

Inborn errors of metabolism

Cystic fibrosis

Extreme prematurity

From KumpfVJ, Chessman KH. Enteral nutrition. In DiPiro JT, falbert RL Yee GG et aL, eds, Pharmacotherapy: A Pathophysiologic Approach, 7th ed. New York: McGraw-Hill, 2008.

Table 101-3 Contraindications and Precautions for EN

Severe hemorrhagic pancreatitis

Severe necrotizing pancreatitis Necrotizing enterocolitis Diffuse peritonitis Small bowel obstruction Paralytic ileus

Severe hemodynamic instability Enterocutaneous fistulae Severe diarrhea Severe malabsorption Severe GI hemorrhage Intractable vomiting

As complications of PN became evident, the pendulum began to swing toward EN in the late 1980s and early 1990s as clinical studies were published showing better clinical outcomes with EN compared with PN. Some of the potential advantages of EN over PN are included here. First, EN is expected to preserve the gut barrier function better than PN. This, in turn, could prevent translocation of bacteria and endotoxin from the gut lumen into the lymphatic system and systemic circulation, thus preventing infections. Studies from the same era support that EN is associated with fewer infectious complications thanPN. EN is cited frequently as having a better overall safety profile than PN. Whereas PN is associated with more severe complications, such as pneumothorax and catheter sepsis, EN is associated with more nuisance complications, such as GI side effects that delay or limit delivery of nutrients. Another major frequently cited advantage of EN over PN is that EN is less expensive. It is true that EN formulas typically are cheaper and less labor intensive to prepare than PN, although some specialty EN formulas approach the cost of PN formulas. However, depending on the method of feeding tube placement, EN costs can mount if the tube must be placed by a radiologist or gastroenterologist rather than a nurse or if the tube must be replaced for some reason.

The arguments in support of EN over PN have been questioned. Part of this questioning relates to the question of whether EN is beneficial compared with PN or whether PN as commonly administered may be detrimental. Overfeeding and hy-

perglycemia occur easily with PN administration, and the potential harm of hyper-glycemia, especially in critical-care populations, has been demonstrated poignantly, although the exact range optimal for glycemic control in the ICU patient remains controversial.10,11 A high-profile study published in 1991 demonstrated in a mildly malnourished perioperative population that there were more infectious complications in patients randomized to receive PN compared with those randomized to receive no SNS; there was no difference in noninfectious complications between the two groups.12

Only in severely malnourished perioperative patients were fewer noninfectious complications seen with PN; in these patients, no difference in infectious complications was seen between groups. Whether EN truly prevents infections and improves clinical outcomes or whether PN is detrimental continues to be debated and is probably dependent on the specific patient population. However, at present, EN is preferred by most experts over PN when the gut is functional. In Europe (more so than in North America), PN is used to supplement EN during the first week of intensive care therapy when EN is not yet being tolerated at full rates.2,13,14 This approach is currently discouraged by the Canadianguidelines and the A.S.P.E.N./SCCM guidelines for SNS in the critically ill patient.3, One meta-analysis did indicate that PN may be superior to delayed EN in critical care.15 Data are emerging to indicate that caloric and protein deficits early in the critical care stay are associated with increased morbidity and mortality; one method to prevent such deficits would be to augment EN with PN until full EN is tolerated.13 The Algorithms for Critical-Care Enteral and Parenteral Therapy (ACCEPT) trial showed that use of an evidence-based algorithm for SNS in critical care patients in community and teaching hospitals improved provision of EN and was associated with reduced hospital stay.1

Herbal Remedies For Acid Reflux

Herbal Remedies For Acid Reflux

Gastroesophageal reflux disease is the medical term for what we know as acid reflux. Acid reflux occurs when the stomach releases its liquid back into the esophagus, causing inflammation and damage to the esophageal lining. The regurgitated acid most often consists of a few compoundsbr acid, bile, and pepsin.

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