The Child with Gastrointestinal Dysfunction

Water Balance in Infants

Compared with older children and adults, infants and young children have a greater need for water and are more vulnerable to alterations in fluid and electrolyte balance. Infants have a greater fluid intake and output relative to size. Water and electrolyte disturbances occur more frequently and more rapidly, and infants and children adjust less promptly to these alterations.

The fluid compartments in the infant vary significantly from those in the adult, primarily because of an expanded extracellular compartment. The extracellular fluid (ECF) compartment constitutes more than half the total body water at birth and has a greater relative content of extracellular sodium and chloride. The infant loses a large amount of fluid at birth and maintains a larger amount of ECF than the adult until about 2 years of age. This contributes to greater and more rapid water loss during this age period.

Fluid losses create compartment deficits that are reflected throughout the duration of dehydration. In general, approximately 60% of fluid is lost from the ECF, and the remaining 40% comes from the intracellular fluid (ICF). The amount of fluid lost from the ECF increases with acute illness and decreases with chronic loss.

Fluid losses vary with age and are divided into insensible, urinary, and fecal losses. Approximately two thirds of insensible losses occur through the skin; the remaining one third is lost through the respiratory tract. Heat and humidity, body temperature, and respiratory rate influence insensible fluid loss. Infants and children have a greater tendency to become highly febrile than do adults. Fever increases insensible water loss approximately 7 ml/kg/24 hr for each degree rise in temperature above 37.2° C (99° F). Fever and increased surface area relative to volume are factors that contribute to greater insensible fluid losses in young patients.

Types of Dehydration

The pathophysiology of dehydration is understood by recognizing that the distribution of water between the ECF and ICF spaces depends on active transport of potassium into and sodium out of cells by energy-requiring processes. Sodium is the chief solute in ECF and is the primary determinant of ECF volume. Potassium is primarily intracellular. When ECF volume is reduced in acute dehydration, the total body sodium content is almost always reduced as well, regardless of serum sodium measurements. Replacement of fluid volume should therefore be accompanied by sodium repletion. Sodium depletion in diarrhea occurs in two ways: out of the body in stool and into the ICF compartment to replace potassium to maintain electrical equilibrium.

Dehydration is classified into three categories on the basis of osmolality and depends primarily on the serum sodium concentration: (1) isotonic, (2) hypotonic, and (3) hypertonic.

Isotonic (isosmotic or isonatremic) dehydration, the primary form of dehydration in children, occurs in conditions in which electrolyte and water deficits are present in approximately balanced proportions. Water and salt are lost in approximately equal amounts. The observable fluid losses are not necessarily isotonic, since losses from other avenues make adjustments so that the sum of all losses, or the net loss, is isotonic. There is no osmotic force between the ICF and the ECF, so the major loss is sustained from the ECF compartment. This significantly reduces the plasma volume and the circulating blood volume, which affects the skin, muscles, and kidneys. Shock is the greatest threat to life, and the child with isotonic dehydration displays symptoms characteristic of hypovolemic shock. Plasma sodium remains within normal limits, between 130 and 150 mEq/L.

Hypotonic (hyposmotic or hyponatremic) dehydration occurs when the electrolyte deficit exceeds the water deficit, leaving the serum hypotonic. Because ICF is more concentrated than ECF in hypotonic dehydration, water moves from the ECF to the ICF to establish osmotic equilibrium. This movement further increases the ECF volume loss, and shock is a frequent finding. Because there is a greater proportional loss of ECF in hypotonic dehydration, the physical signs tend to be more severe with smaller fluid losses than with isotonic or hypertonic dehydration. Serum sodium concentration is less than 130 mEq/L.

Hypertonic (hyperosmotic or hypernatremic) dehydration results from water loss in excess of electrolyte loss and is usually caused by a proportionately larger loss of water or a larger intake of electrolytes. This type of dehydration is the most dangerous and requires more specific fluid therapy. Hypertonic diarrhea may occur in infants who are given fluids by mouth that contain large amounts of solute, or in children who receive high-protein nasogastric (NG) tube feedings that place an excessive solute load on the kidneys. In hypertonic dehydration, fluid shifts from the lesser concentration of the ICF to the ECF. Plasma sodium concentration is greater than 150 mEq/L.

Because the ECF volume is proportionately larger, hypertonic dehydration consists of a greater degree of water loss for the same intensity of physical signs. Shock is less apparent. However, neurologic disturbances, including alterations in consciousness, poor ability to focus attention, lethargy, increased muscle tone with hyperreflexia, and hyperirritability to stimuli, are more likely to occur. Cerebral changes are serious and may result in permanent damage.

Diagnostic Evaluation

Diagnosis of the type and degree of dehydration is necessary to develop an effective plan of therapy. The degree of dehydration has been described as a percentage: 3% to 5% (mild), 6% to 9% (moderate), or more than 10% (severe) (American Academy of Pediatrics, 1996). Water constitutes only 60% to 70% of the infant’s weight. However, adipose tissue contains little water and is highly variable in individual infants and children. A more accurate means of describing dehydration is to reflect acute loss (over 48 hours or less) in milliliters per kilogram of body weight. For example, a loss of 50 ml/kg is considered to be a mild fluid loss, whereas a loss of 100 ml/kg produces severe dehydration. Weight is the most important determinant of the percent of total body fluid loss in infants and younger children. However, often the preillness weight is unknown. Other predictors of fluid loss include a changing level of consciousness (irritability to lethargy), response to stimuli, decreased skin elasticity and turgor, prolonged capillary refill, increased heart rate, and sunken eyes and fontanels. Clinical signs provide clues to the extent of dehydration (Table 24-1). Using multiple predictors increases the sensitivity of assessing the fluid deficit, and early studies have shown a reasonably high degree of agreement between experienced observers in assessment of the level of dehydration. Objective signs of dehydration are present at a fluid deficit of less than 5%. Any two of the following signs—capillary refill of 2 seconds, absent tears, dry mucous membranes, and an ill general appearance—are predictors of a deficit of at least 5%. Generally, three or more clinical findings are present at a deficit of 5% to 9%, and four or more findings are found with a deficit of 10% or more (Steiner, DeWalt, Byerley, and others, 2004). Shock, tachycardia, and very low blood pressure are common features of severe depletion of ECF volume (see Shock, Chapter 25).

Therapeutic Management

See discussion on therapeutic management of diarrhea, p. 821.

Nursing Care Management

Nursing observation and intervention are essential for detection and therapeutic management of dehydration. A variety of circumstances cause fluid losses in infants, and changes can take place quickly. An important nursing responsibility is observation for signs of dehydration. Nursing assessment should begin with observation of general appearance and proceed to more specific observations. Conditions in which dehydration may develop quickly include diarrhea; vomiting; sweating; fever; disorders such as diabetes, renal disease, and cardiac anomalies; administration of certain drugs (such as diuretics and steroids); and trauma (major surgery, burns, and other extensive injury).

Etiology

Most pathogens that cause diarrhea are spread by the fecal-oral route through contaminated food or water or are spread from person to person where there is close contact (e.g., daycare centers). Lack of clean water, crowding, poor hygiene, nutritional deficiency, and poor sanitation are major risk factors, especially for bacterial or parasitic pathogens. The increased frequency and severity of diarrheal disease in infants is also related to age-specific alterations in susceptibility to pathogens. For example, the immune system of infants has not been exposed to many pathogens and has not acquired protective antibodies. Worldwide, the most common causes of acute gastroenteritis are infectious agents, viruses, bacteria, and parasites. In developed nations, viruses, primarily rotavirus, cause 70% to 80% of infectious diarrhea.

Rotavirus is the most important cause of serious gastroenteritis among children and a significant nosocomial (hospital-acquired) pathogen, accounting for 55,000 to 70,000 hospitalizations annually (Staat, 2006). Rotavirus disease is most severe in children 3 to 24 months of age. Children younger than 3 months of age have some protection from the disease because of maternally acquired antibodies. Approximately 25% of severe cases of rotavirus occur in older children (Coffin, 2001).

Salmonella, Shigella, and Campylobacter organisms are the most frequently isolated bacterial pathogens. Salmonella has the highest occurrence in infants; Giardia and Shigella have the highest incidence among toddlers. Shigella infection is uncommon in the United States, accounting for less than 5% of diarrheal illnesses in infants and toddlers. Campylobacter infection has a bimodal presentation (highest in children less than 12 months of age with a second rise in incidence at age 15 to 19 years). Giardia and Cryptosporidium organisms are parasites. Giardia infection represents 15% of nondysenteric illness in the United States; Cryptosporidium infection is often associated with outbreaks in young children in daycare centers. Plesiomonas and Yersinia are also parasites that are frequently responsible for causing diarrhea that lasts more than 10 days in a previously healthy adolescent. (See also Intestinal Parasitic Diseases, Chapter 14.)

Antibiotic administration is frequently associated with diarrhea because antibiotics alter the normal intestinal flora, resulting in an overgrowth of other bacteria such as Clostridium difficile. National rates of C. difficile have more than doubled since 2000 (Richards, 2006). Antibiotic-associated diarrhea can also be caused by Salmonella organisms, Clostridium porringers type A, and Staphylococcus aureus pathogens (Jabbar and Wright, 2003).

Pathophysiology

Invasion of the GI tract by pathogens results in increased intestinal secretion as a result of enterotoxins, cytotoxic mediators, or decreased intestinal absorption secondary to intestinal damage or inflammation. Enteric pathogens attach to the mucosal cells and form a cuplike pedestal on which the bacteria rest. The pathogenesis of the diarrhea depends on whether the organism remains attached to the cell surface, resulting in a secretory toxin (noninvasive, toxin-producing, noninflammatory type diarrhea), or penetrates the mucosa (systemic diarrhea). Noninflammatory diarrhea is the most common diarrheal illness, resulting from the action of enterotoxin that is released after attachment to the mucosa (Ramaswamy and Jacobson, 2001). The most serious and immediate physiologic disturbances associated with severe diarrheal disease are (1) dehydration, (2) acid-base imbalance with acidosis, and (3) shock that occurs when dehydration progresses to the point that circulatory status is seriously impaired.

Diagnostic Evaluation

Evaluation of the child with acute gastroenteritis begins with a careful history that seeks to discover the possible cause of diarrhea, to assess the severity of symptoms and the risk of complications, and to elicit information about current symptoms indicating other treatable illnesses that could be causing the diarrhea. The history should include questions about recent travel, exposure to untreated drinking or washing water sources, contact with animals or birds, daycare center attendance, recent treatment with antibiotics, or recent diet changes. History questions should also explore the presence or absence of other symptoms such as fever and vomiting, frequency and character of stools (e.g., watery, bloody), urinary output, dietary habits, and recent food intake.

Extensive laboratory evaluation is not indicated in children who have uncomplicated diarrhea and no evidence of dehydration, since most diarrheal illnesses are self-limiting. Laboratory tests are indicated for children who are severely dehydrated and receiving intravenous (IV) therapy. Watery, explosive stools suggest glucose intolerance; foul-smelling, greasy, bulky stools suggest fat malabsorption. Diarrhea that develops after the introduction of cow’s milk, fruits, or cereal may be related to enzyme deficiency or protein intolerance. Neutrophils or red blood cells in the stool indicate bacterial gastroenteritis or IBD. The presence of eosinophils suggests protein intolerance or parasitic infection. Stool cultures should be performed only when blood, mucus, or polymorphonuclear leukocytes are present in the stool, when symptoms are severe, when there is a history of travel to a developing country, and when a specific pathogen is suspected. Gross blood or occult blood may indicate pathogens such as Shigella, Campylobacter, or hemorrhagic Escherichia coli strains. An enzyme-linked immunosorbent assay (ELISA) may be used to confirm the presence of rotavirus or Giardia organisms. If there is a history of recent antibiotic use, the stool should be tested for C. difficile toxin. When bacterial and viral cultures are negative and when diarrhea persists for more than a few days, stools should be examined for ova and parasites. A stool specimen with a pH of less than 6 and the presence of reducing substances may indicate carbohydrate malabsorption or secondary lactase deficiency. Stool electrolyte measurements may help identify children with secretory diarrhea.

Urine specific gravity should be determined if dehydration is suspected. A complete blood count (CBC), serum electrolytes, creatinine, and blood urea nitrogen (BUN) should be obtained in the child who requires hospitalization. The hemoglobin, hematocrit, creatinine, and BUN levels are usually elevated in acute diarrhea and should normalize with rehydration.

Therapeutic Management

The major goals in the management of acute diarrhea include (1) assessment of fluid and electrolyte imbalance, (2) rehydration, (3) maintenance fluid therapy, and (4) reintroduction of an adequate diet. Infants and children with acute diarrhea and dehydration should be treated first with oral rehydration therapy (ORT). ORT is one of the major worldwide health care advances. It is more effective, safer, less painful, and less costly than IV rehydration. The American Academy of Pediatrics, World Health Organization, and Centers for Disease Control and Prevention all recommend ORT as the treatment of choice for most cases of dehydration caused by diarrhea (American Academy of Pediatrics, 2001). Oral rehydration solutions (ORSs) enhance and promote the reabsorption of sodium and water, and studies indicate that these solutions greatly reduce vomiting, volume loss from diarrhea, and the duration of the illness. ORSs, including reduced osmolarity ORS, are available in the United States as commercially prepared solutions and are successful in treating the majority of infants with dehydration. Guidelines for rehydration recommended by the American Academy of Pediatrics are included in Box 24-3.

After rehydration, ORS may be used during maintenance fluid therapy by alternating the solution with a low-sodium fluid such as water, breast milk, lactose-free formula, or half-strength lactose-containing formula. In older children ORS can be given and a regular diet continued. Ongoing stool losses should be replaced on a 1:1 basis with ORS. If the stool volume is not known, approximately 10 ml/kg (4 to 8 ounces) of ORS should be given for each diarrheal stool.

Solutions for oral hydration are useful in most cases of dehydration, and vomiting is not a contraindication. A child who is vomiting should be given an ORS at frequent intervals and in small amounts. For young children the caregiver may give the fluid with a spoon or small syringe in 5- to 10-ml increments every 1 to 5 minutes. An ORS may also be given via NG or gastrostomy tube infusion. Infants without clinical signs of dehydration do not need ORT. They should, however, receive the same fluids recommended for infants with signs of dehydration in the maintenance phase and for ongoing stool losses. The use of probiotics reduces the risk of antibiotic-associated diarrhea in children by 56% (Szajewska, Ruszcynski, and Radzikowski, 2006).

Prevention

Human-bovine reassortant rotavirus vaccine (RotaTeq) became available in 2006, and live-attenuated human rotavirus vaccine (Rotarix) will be available soon for the prevention of rotavirus. Infants should receive three doses of RotaTeq oral vaccine at 2, 4, and 6 months of age. Two doses of Rotarix will induce protective immunity (Marshall, 2006).

Early reintroduction of nutrients is desirable and is gaining more widespread acceptance. Continued feeding or early reintroduction of a normal diet has no adverse effects and actually lessens the severity and duration of the illness and improves weight gain when compared with the gradual reintroduction of foods (Zangwill, 2006). Infants who are breastfeeding should continue to do so, and ORS should be used to replace ongoing losses in these infants. Formula-fed infants should resume their formula; if it is not tolerated, a lactose-free formula may be used for a few days. In older children a regular diet, including milk, can generally be offered after rehydration has been achieved. In toddlers there is no contraindication to continuing soft or pureed foods. A diet of easily digestible foods such as cereals, cooked vegetables, and meats is adequate for the older child.

In cases of severe dehydration and shock, IV fluids are initiated whenever the child is unable to ingest sufficient amounts of fluid and electrolytes to (1) meet ongoing daily physiologic losses, (2) replace previous deficits, and (3) replace ongoing abnormal losses. Patients who usually require IV fluids are those with severe dehydration, those with uncontrollable vomiting, those who are unable to drink for any reason (e.g., extreme fatigue, coma), and those with severe gastric distention.

The IV solution is selected on the basis of what is known regarding the probable type and cause of the dehydration—usually a saline solution containing 5% dextrose in water. Sodium bicarbonate may be added, since acidosis is usually associated with severe dehydration. Although the initial phase of fluid replacement is rapid in both isotonic and hypotonic dehydration, rapid fluid replacement is contraindicated in hypertonic dehydration because of the risk of water intoxication, especially in the brain cells.

After the severe effects of dehydration are under control, specific diagnostic and therapeutic measures are begun to detect and treat the cause of the diarrhea. Because of the self-limiting nature of vomiting and its tendency to improve when dehydration is corrected, the use of antiemetic agents is not recommended. The use of antibiotic therapy in children with acute gastroenteritis is controversial. Antibiotics may shorten the course of some diarrheal illnesses (e.g., those caused by Shigella organisms). However, most bacterial diarrheas are self-limiting, and the diarrhea often resolves before the causative organism can be determined. Antibiotics may prolong the carrier period for bacteria such as Salmonella. Antibiotics may be considered, however, in patients with immunosuppression, severe symptoms, or persistent disease or in patients who have had transplantation (Jabbar and Wright, 2003) (see Intestinal Parasitic Diseases, Chapter 14).

Nursing Care Management

The management of most cases of acute diarrhea takes place in the home with education of the caregiver. Caregivers are taught to monitor for signs of dehydration (especially the number of wet diapers or voidings) and the amount of fluids taken by mouth, and to assess the frequency and amount of stool losses. Education relating to ORT, including the administration of maintenance fluids and replacement of ongoing losses, is important (see Critical Thinking Exercise). ORS should be administered in small quantities at frequent intervals. Vomiting is not a contraindication to ORT unless it is severe. Information concerning the introduction of a normal diet is essential. Parents need to know that a slightly higher stool output initially occurs with continuation of a normal diet and with ongoing replacement of stool losses. The benefits of a better nutritional outcome with fewer complications and a shorter duration of illness outweigh the potential increase in stool frequency. Parents’ concerns should be addressed to ensure adherence to the treatment plan.

If the child with acute diarrhea and dehydration is hospitalized, an accurate weight must be obtained, as well as careful monitoring of intake and output. The child may be placed on parenteral fluid therapy with nothing by mouth (NPO) for 12 to 48 hours. Monitoring the IV infusion is an important nursing function. The nurse must ensure that the correct fluid and electrolyte concentration is infused, that the flow rate is adjusted to deliver the desired volume in a given time, and that the IV site is maintained.

Accurate measurement of output is essential to determine whether renal blood flow is sufficient to permit the addition of potassium to the IV fluids. The nurse is responsible for examination of stools and collection of specimens for laboratory examination (see Collection of Specimens, Chapter 22). Care should be taken when obtaining and transporting stools to prevent possible spread of infection. A clean tongue depressor can be used to obtain specimens for laboratory examination or as an applicator for transfer to a culture medium. Stool specimens should be transported to the laboratory in appropriate containers and media according to hospital policy.

Diarrheal stools are highly irritating to the skin, and extra care is needed to protect the skin of the diaper region from excoriation (see Diaper Dermatitis, Chapter 30). Rectal temperatures are avoided because they stimulate the bowel, increasing passage of stool.

Support for the child and family involves the same care and consideration given all hospitalized children (see Chapter 21). Parents are kept informed of the child’s progress and instructed in the use of frequent and proper hand washing and the disposal of soiled diapers, clothes, and bed linen. Everyone caring for the child must be aware of “clean” areas and “dirty” areas, especially in the hospital, where the sink in the child’s room is used for many purposes. Soiled diapers and linen should be discarded in receptacles close to the bedside. To remind caregivers to keep diapers and other soiled articles away from clean areas, place signs identifying “clean” (e.g., bed table) and “dirty” (e.g., sink, bathroom) areas. List the articles that may be stored in each area on these signs.

Newborn Period

Normally the newborn infant passes a first meconium stool within 24 to 36 hours of birth. Any infant who does not do so should be assessed for evidence of intestinal atresia or stenosis, HD, hypothyroidism, meconium plugs, or meconium ileus. Meconium plugs are caused by meconium that has reduced water content and are usually evacuated after digital examination but may require irrigations with a hypertonic solution or contrast medium.

Meconium ileus, the initial manifestation of cystic fibrosis, is the luminal obstruction of the distal small intestine by abnormal meconium. Treatment is the same as for a meconium plug; early surgical intervention may be needed to evacuate the small intestine.

Infancy

The onset of constipation frequently occurs during infancy and may result from organic causes such as HD, hypothyroidism, and strictures. It is important to differentiate these conditions from functional constipation. Constipation in infancy is often related to dietary practices. It is less common in breast-fed infants, who have softer stools than bottle-fed infants. Breast-fed infants may also have decreased stools because of more complete use of breast milk with little residue. When constipation occurs with a change from human milk or modified cow’s milk to whole cow’s milk, simple measures such as adding or increasing the amount of cereal, vegetables, and fruit in the infant’s diet usually corrects the problem. When a bottle-fed infant passes a hard stool that results in an anal fissure, stool-withholding behaviors may develop in response to pain on defecation (see Critical Thinking Exercise).

Childhood

Most constipation in early childhood is due to environmental changes or normal development when a child begins to attain control over bodily functions. A child who has experienced discomfort during bowel movements may deliberately try to withhold stool. Over time, the rectum accommodates to the accumulation of stool, and the urge to defecate passes. When the bowel contents are ultimately evacuated, the accumulated feces are passed with pain, thus reinforcing the desire to withhold stool.

Constipation in school-age children may represent an ongoing problem or a first-time event. The onset of constipation at this age is often the result of environmental changes, stresses, and changes in toileting patterns. A common cause of new-onset constipation at school entry is fear of using the school bathrooms, which are noted for their lack of privacy. Early and hurried departure for school immediately after breakfast may also impede bathroom use.

The management of simple constipation consists of a plan to promote regular bowel movements. Often this is as simple as changing the diet to provide more fiber and fluids, eliminating foods known to be constipating, and establishing a bowel routine that allows for regular passage of stool. Stool-softening agents such as docusate or lactulose may also be helpful. Polyethylene glycol (PEG) 3350 without electrolytes (Miralax) is a chemically inert polymer that has been introduced as a new laxative in recent years. It is tolerated well by children because it can be mixed in a beverage of choice (Loening-Baucke and Pashankar, 2006). If other symptoms such as vomiting, abdominal distention, or pain and evidence of growth failure are associated with the constipation, the condition should be investigated further.

Nursing Care Management

Constipation tends to be self-perpetuating. A child who has difficulty or discomfort when attempting to evacuate the bowels has a tendency to retain the bowel contents, and this may initiate a vicious circle. Nursing assessment begins with an accurate history of bowel habits; diet; events associated with the onset of constipation; drugs or other substances that the child may be taking; and the consistency, color, frequency, and other characteristics of the stool. If there is no evidence of a pathologic condition, the major task is to educate the parents regarding normal stool patterns and to participate in the education and treatment of the child.

Dietary modifications are essential in preventing constipation. During infancy, simply increasing the carbohydrate (sugar or corn syrup) in the infant’s formula will often relieve the problem. During childhood the diet should contain increased amounts of fiber and fluid. Parents benefit from guidance in selecting foods that facilitate bowel movements (Box 24-4). They need reassurance concerning the benign nature of the condition. It is also important to discuss their attitudes and expectations regarding toilet habits.

When constipation persists despite dietary intervention, more aggressive management may be necessary. It is important to differentiate an acute episode of constipation from chronic functional constipation, which can result from chronic stool-withholding behavior. As the rectal vault becomes distended over time, further complications such as fecal impaction and encopresis may develop (see Chapter 17).

Pathophysiology

HD is a developmental disorder of the enteric nervous system that is characterized by the absence of ganglion cells, originating in from the neural crest, in both the Auerbach myenteric and Meissner submucosal plexuses of the distal intestine. The length of the aganglionic distal bowel depends on the timing of the arrest in craniocaudal migration of ganglion cells. The aganglionic bowel is chronically contracted. This results in absent peristalsis in the affected bowel and the development of a functional intestinal obstruction (Fig. 24-1) (Dasgupta and Langer, 2004). Intestinal distention and ischemia may also occur as a result of distention of the bowel wall, which contributes to the development of enterocolitis (inflammation of the small bowel and colon). Enterocolitis is characterized by fever, abdominal distention, and diarrhea that may be severe and lead to life-threatening dehydration or sepsis (Dasgupta and Langer, 2004).

Diagnostic Evaluation

Most children with HD are diagnosed in the first few months of life. Clinical manifestations vary according to the age when symptoms are recognized and the presence of complications, such as enterocolitis (Box 24-5). A neonate usually is seen with distended abdomen, feeding intolerance with bilious vomiting, and delay in the passage of meconium. Typically, 95% of normal term infants pass meconium in the first 24 hours of life, whereas less than 10% of infants with HD do so. In older children, a careful history is helpful. Radiographs, an unprepped barium enema, and anorectal manometric examinations assist in the differential diagnosis, which is confirmed by a full-thickness rectal biopsy demonstrating the absence of ganglion cells in the myenteric and submucosal plexuses.

Therapeutic Management

Treatment is primarily surgery to remove the aganglionic portion of the bowel to relieve obstruction and restore normal bowel motility and function of the internal anal sphincter. If the bowel is not significantly distended, this is accomplished in one surgery. However, in most cases two stages are required. First, a temporary ostomy is created proximal to the aganglionic segment to relieve obstruction and allow the normally enervated and dilated bowel to return to its normal size. Complete corrective surgery is performed later. The various surgical procedures that can be performed are the Swenson, Duhamel, Boley, and Soave procedures. The Soave endorectal pull-through procedure, one of the most frequently used procedures, consists of pulling the end of the normal bowel through the muscular sleeve of the rectum, from which the aganglionic mucosa has been removed. The ostomy is usually closed at the time of the pull-through procedure.

Nursing Care Management

The nursing concerns depend on the child’s age and the type of treatment. If the disorder is diagnosed during the neonatal period, the main objectives are (1) to help the parents adjust to a congenital defect in their child, (2) to foster infant-parent bonding, (3) to prepare them for the medical-surgical intervention, and (4) to assist them in colostomy care after discharge.

Therapeutic Management

Management is directed toward detection and treatment of the cause of the vomiting and prevention of complications from the loss of fluid. Fluids are administered in the same manner and in a similar electrolyte composition to those administered for diarrhea. Although most children respond to these measures, antiemetic drugs may be needed. Antiemetics such as ondansetron (Zofran) and trimethobenzamide (Tigan) block receptors in the chemoreceptor trigger zone; others such as metoclopramide (Reglan) enhance gastroduodenal peristalsis; still others such as promethazine (Phenergan) compete for H₁-receptor sites. For children who are prone to motion sickness, it is helpful to administer an appropriate dose of dimenhydrinate (Dramamine) before a trip.

Nursing Care Management

The major focus of nursing care is observation and reporting of vomiting behavior and associated symptoms and the implementation of measures to reduce the vomiting. Accurate assessment of the type of vomiting, the appearance of the vomitus, and the child’s behavior in association with the vomiting helps to establish a diagnosis.

Nursing interventions are determined by the cause of the vomiting. When the vomiting is a manifestation of improper feeding methods, establishing proper techniques through teaching and example will usually correct the situation. If vomiting is believed to be an indication of obstruction, food is usually withheld or special feeding techniques are implemented. In situations in which vomiting is related to concurrent infection, dietary indiscretion, or emotional factors, efforts are directed toward maintaining hydration or preventing dehydration.

The thirst mechanism is the most sensitive guide to fluid needs, and ad libitum administration of a glucose-electrolyte solution to an alert child will restore water and electrolytes satisfactorily. It is important to include carbohydrate to spare body protein and avoid ketosis resulting from exhaustion of glycogen stores. Small, frequent feedings of fluids or foods are preferred. After vomiting has stopped, more liberal amounts of fluids are offered, followed by gradual resumption of the regular diet.

The vomiting infant or child is positioned on the side or semireclining to prevent aspiration and observed for evidence of dehydration. It is important to emphasize the need for the child to brush the teeth or rinse the mouth after vomiting to dilute hydrochloric acid that comes in contact with the teeth. A flavored mouthwash or tooth brushing will freshen the mouth. Careful monitoring of fluid and electrolyte status is necessary to prevent an electrolyte disturbance.

Pathophysiology

Although the pathogenesis of GER is multifactorial, its primary causative mechanism likely involves inappropriate transient relaxation of the lower esophageal sphincter (LES) (Suwandhi, Ton, and Schwarz, 2006). Factors that increase abdominal pressure such as coughing and sneezing, scoliosis, and overeating may contribute to GERD. Esophageal symptoms are caused by inflammation from the acid in the gastric refluxate, whereas reactive airway disease may result from stimulation of airway reflexes by the acid refluxate.

Diagnostic Evaluation

The history and physical examination are usually sufficiently reliable to establish the diagnosis of GER. However, the upper GI series is helpful in evaluating the presence of anatomic abnormalities (e.g., pyloric stenosis, malrotation, annular pancreas, hiatal hernia, esophageal stricture). The 24-hour intraesophageal pH monitoring study is the gold standard in the diagnosis of GER (Suwandhi, Ton, and Schwarz, 2006). Endoscopy with biopsy may be helpful to assess the presence and severity of esophagitis, strictures, and Barrett esophagus and to exclude other disorders such as Crohn disease. Scintigraphy detects radioactive substances in the esophagus after a feeding of the compound and assesses gastric emptying. It can differentiate between aspiration of gastric contents from reflux vs aspiration from poor oropharyngeal muscle coordination.

Therapeutic Management

Therapeutic management of GER depends on its severity. No therapy is needed for the infant who is thriving and has no respiratory complications. Avoidance of certain foods that exacerbate acid reflux (e.g., caffeine, citrus, tomatoes, alcohol, peppermint, spicy or fried foods), lifestyle modifications in children (e.g., weight control if indicated; small, more frequent meals; smoking cessation), and feeding maneuvers in infants (e.g., thickened feedings, upright positioning) can improve mild GER symptoms. Thickened feedings do not improve pH scores on 24-hour intraesophageal monitoring but may decrease the number of vomiting episodes. Feedings thickened with 1 teaspoon to 1 tablespoon of rice cereal per ounce of formula may be recommended. This may benefit infants who are underweight as a result of GERD. Constant NG feedings may be necessary for the infant with severe reflux and failure to thrive until surgery can be performed. Elevating the head of the bed 30 degrees or placing the infant in an infant seat elevated 30 degrees for 1 hour after feedings may decrease GER. Prone positioning of infants also decreases episodes of GER but is recommended only with extreme caution when the risk of GERD complications exceeds the risk of sudden infant death syndrome (Cavataio and Guandalini, 2005). The American Academy of Pediatrics recommends supine positioning for sleep (see Chapter 11). If the prone position is used, parents need to be cautioned to avoid soft bedding.

Pharmacologic therapy may be used to treat infants and children with GERD. Both H₂-receptor antagonists (cimetidine [Tagamet], ranitidine [Zantac], or famotidine [Pepcid]) and proton pump inhibitors (PPIs; esomeprazole [Nexium], lansoprazole [Prevacid], omeprazole [Prilosec], pantoprazole [Protonix], and rabeprazole [Aciphex]) reduce gastric hydrochloric acid secretion and may stimulate some increase in LES tone. Use of available prokinetic drugs (e.g., bethanechol [Urecholine] and metoclopramide) remains controversial. Careful analyses of published data have failed to demonstrate clinical efficacy in modifying the natural history or therapeutic outcomes of GER in childhood (Suwandhi, Ton, and Schwartz, 2006).

Surgical management of GER is reserved for children with severe complications such as recurrent aspiration pneumonia, apnea, severe esophagitis, or failure to thrive, and for children who have failed to respond to medical therapy. The Nissen fundoplication (Fig. 24-2) is the most common surgical procedure (Christian and Buyske, 2005). This surgery involves passage of the gastric fundus behind the esophagus to encircle the distal esophagus. The most recent surgical advance is the introduction of the laparoscopic Nissen fundoplication (Jackson, Gleiber, Askar, and others, 2001). Complications following fundoplication include breakdown of the wrap, small bowel obstruction, gas-bloat syndrome, infection, retching, and dumping syndrome (Rudolph, Mazur, Liptak, and others, 2001).

Nursing Care Management

Nursing care is directed at (1) identifying children with symptoms; (2) educating parents regarding home care, including feeding, positioning, and medications; and (3) if appropriate, providing care for the child undergoing surgical repair (see Surgical Procedures, Chapter 22). Early in the treatment program, parents should be reassured that most infants and children outgrow GER and often conservative lifestyle changes are sufficient. Parents need support and reassurance to implement lifestyle changes. Although it is not known if lifestyle changes bring additional benefit to patients receiving pharmacologic interventions, some changes may be helpful. To help parents cope with the inconvenience of dealing with a child who spits up frequently, simple measures such as using bibs and protective cloths during and after feedings are beneficial. Older children and adolescents need to know that caffeine, chocolate, and spicy foods may weaken the LES and aggravate symptoms. Exposure to tobacco and alcohol are also associated with GER. Obesity increases abdominal pressure, and weight management may reduce GER symptoms. When medical management is necessary, parents need information about the medications and their potential side effects. Prokinetic medications must be given before feedings. Medications for acid control must be timed to provide coverage and given regularly and as ordered.

Etiology

There is a higher seasonal prevalence of abdominal pain symptoms during winter months, suggesting that school-related stressors and daylight hours may play a role. Also, an increased prevalence has been found among first-degree relatives.

Pathophysiology

Although the pathogenesis of functional abdominal pain disorders is incompletely understood, most investigators agree on a multifactorial etiology and the presence of an altered brain-gut interaction (Saps and Li, 2006). Children with FAP exhibit generalized visceral hyperanalgesia, whereas those with IBS exhibit rectal hyperanalgesia (DiLorenzo, Youssef, Sigurdsson, and others, 2001). All may have abnormal GI motility.

Diagnostic Evaluation

Exclusion of an organic condition can usually be accomplished through screening diagnostic tests such as CBC; erythrocyte sedimentation rate (ESR); liver transaminases; celiac antibodies; urinalysis; and stool examination for blood, ova, or parasites (Saps and Li, 2006).

Therapeutic Management

Alleviating symptoms is the main goal when treating children with functional abdominal pain disorders because complete eradication of pain often is impossible. Children may experience reduced pain with the use of anticholinergics, tricyclic antidepressants, selective serotonin reuptake inhibitors (SSRIs), or serotonin receptor modulators. Children with FAP may benefit from a smooth muscle relaxant. Children with constipation-dominant IBS may find relief by increasing fiber combined with a laxative as necessary, whereas those with diarrhea-dominant IBS may experience relief by increasing fiber and adding an antidiarrheal medication as necessary. Antimigraine therapy is often used to prevent recurrences of abdominal migraine or to abort attacks.

Nursing Care Management

It is important to validate the child’s symptoms by stating that the pain is “real,” not just “in the head” (Saps and Li, 2006). In addition to medications, children with functional abdominal pain disorders may benefit from relaxation training. The goals are to return the child to functional status, attending school and extracurricular activities.

Etiology

The cause of appendicitis is obstruction of the lumen of the appendix, usually by hardened fecal material (fecalith). Swollen lymphoid tissue, frequently occurring after a viral infection, can also obstruct the appendix. Another rare cause of obstruction is a parasite such as Enterobius vermicularis, or pinworms, which can obstruct the appendiceal lumen.

Pathophysiology

With acute obstruction, the outflow of mucus secretions is blocked and pressure builds within the lumen, resulting in compression of blood vessels. The resulting ischemia is followed by ulceration of the epithelial lining and bacterial invasion. Subsequent necrosis causes perforation or rupture with fecal and bacterial contamination of the peritoneal cavity. The resulting inflammation spreads rapidly throughout the abdomen (peritonitis), especially in young children, who are unable to localize infection. Progressive peritoneal inflammation results in functional intestinal obstruction of the small bowel (ileus) because intense GI reflexes severely inhibit bowel motility. Because the peritoneum represents a major portion of total body surface, the loss of ECF to the peritoneal cavity leads to electrolyte imbalance and hypovolemic shock.

Diagnostic Evaluation

Diagnosis is not always straightforward. Fever, vomiting, abdominal pain, and an elevated white blood count are associated with appendicitis but are also seen in IBD, pelvic inflammatory disease, gastroenteritis, urinary tract infection, right lower lobe pneumonia, mesenteric adenitis, Meckel diverticulum, and intussusception. Prolonged symptoms and delayed diagnosis often occur in younger children, in whom the risk of perforation is greatest because of their inability to verbalize their complaints.

The diagnosis is based primarily on the history and physical examination (Box 24-7). Pain, the cardinal feature, is initially generalized (usually periumbilical); however, it usually descends to the lower right quadrant. The most intense site of pain may be at McBurney point, located at a point midway between the anterior superior iliac crest and the umbilicus. Rebound tenderness is not a reliable sign and is extremely painful to the child. Referred pain, elicited by light percussion around the perimeter of the abdomen, indicates peritoneal irritation. Movement, such as riding over bumps in an automobile or gurney, aggravates the pain. In addition to pain, significant clinical manifestations include fever, a change in behavior, anorexia, and vomiting.

Laboratory studies usually include a CBC; urinalysis (to rule out a urinary tract infection); and, in adolescent females, serum human chorionic gonadotropin (to rule out an ectopic pregnancy). A white blood cell (WBC) count greater than 10,000/mm³ and a C-reactive protein (CRP) are common but are not necessarily specific for appendicitis. An elevated percentage of bands (often referred to as “a shift to the left”) may indicate an inflammatory process. CRP is an acute-phase reactant that rises within 12 hours of the onset of infection.

Computed tomography (CT) scan has become the imaging technique of choice, although ultrasound may also be helpful in diagnosing appendicitis. A CT scan is considered positive in the presence of enlarged appendiceal diameter; appendiceal wall thickening; and periappendiceal inflammatory changes, including fat streaks, phlegmon, fluid collection, and extraluminal gas (Kaiser, Frenchner, and Jorulf, 2002).

Therapeutic Management

Treatment of appendicitis before perforation includes rehydration, antibiotics, and surgical removal of the appendix (appendectomy). Laparoscopic surgery is now commonly used to treat nonperforated acute appendicitis (Holcomb, 2001). Recovery is rapid, and, if no complications occur, the hospital stay is short.

Nursing Care Management

Because abdominal pain is the most common childhood complaint with appendicitis, it is important to assess the severity of pain (see Pain Assessment, Chapter 7). One of the most reliable estimates is the degree of change in behavior. The younger, nonverbal child will assume a rigid, motionless, side-lying posture with the knees flexed on the abdomen, and there is decreased range of motion of the right hip. Older children may exhibit all of these behaviors while complaining of abdominal pain. They can always indicate a point at which the pain is worse than at any other location.

Pathophysiology

The symptomatic complications of Meckel diverticulum are ulceration, bleeding, intussusception, intestinal obstruction, diverticulitis, and perforation; bleeding is the most common problem in children. Gastric mucosa is the most common ectopic tissue found in Meckel diverticulum. Bleeding is caused by peptic ulceration or perforation because of the unbuffered acidic gastric secretion. Several mechanisms can cause obstruction. Intussusception may be led by the diverticulum. Obstruction may also be caused by entanglement of the small intestine around a fibrous cord, trapping of a loop of intestine under the band, incarceration within a hernia sac, or volvulus of the intestinal segment containing the diverticulum. Diverticulitis occurs when peptic ulceration or obstruction leads to inflammation.

Diagnostic Evaluation

Diagnosis is usually based on the history, physical examination, and a specialized radiographic study. The most common clinical presentation in children includes painless rectal bleeding, abdominal pain, or signs of intestinal obstruction (Box 24-8). Bleeding, which may be mild or profuse, often appears as dark red or “currant jelly” stools; bleeding may be significant enough to cause hypotension. The Meckel scan, a technetium-99m pertechnate scan, detects the presence of gastric mucosa with an overall diagnostic accuracy of 90%. Blood studies are performed to screen for bleeding disorders and anemia.

Therapeutic Management

The standard treatment is surgical removal of the diverticulum. When severe hemorrhage increases the surgical risk, interventions to correct hypovolemic shock, such as blood replacement, IV fluids, and oxygen, may be necessary. Antibiotics may be used preoperatively to control infection. If intestinal obstruction has occurred, appropriate preoperative measures are used to reverse electrolyte imbalances and prevent abdominal distention.

Nursing Care Management

Nursing objectives are similar to those for any child undergoing surgery (see Chapter 22). Because the onset of this condition is often rapid, parents require psychologic support. The massive intestinal bleeding that can accompany a Meckel diverticulum is traumatic to both the child and the parents and may significantly affect their emotional reaction to hospitalization and surgery.

Specific preoperative considerations with intestinal bleeding include (1) frequent monitoring of vital signs and blood pressure for shock, (2) keeping the child on bed rest, and (3) recording the approximate amount of blood lost in stools. In the absence of frank hemorrhage, the nurse tests the stools for occult blood. Postoperatively, the child requires IV fluids and an NG tube for the decompression and evacuation of gastric contents.

Etiology

Despite decades of research, the etiology of IBD is not completely understood, and there is no known cure. There is evidence to indicate a multifactorial etiology. Research is focused on theories of defective immunoregulation of the inflammatory response to bacteria or viruses in the GI tract in individuals with a genetic predisposition (Silbermintz and Markowitz, 2006). In CD the chronic immune process is characterized by a T helper 1 cytokine profile, whereas in UC the response is more humoral and mediated by T helper 2 cells (Silbermintz and Markowitz, 2006). An epidemiologic study by Kugathasan, Judd, Hoffman, and others (2003) found an equal distribution of IBD among all racial and ethnic groups, contrasting with earlier studies that suggested IBD typically affects Caucasians (especially Ashkenazi Jews) more than those of Asian or African decent. The Kugathasan study also did not demonstrate a higher risk for developing IBD in urban populations, as had been reported in earlier studies.

There is an influence of genetics in the development of CD. Several CD susceptibility genes have now been identified, including NOD2/CARD15 on chromosome 16 associated with ileal disease, IBD5 on chromosome 5, and IBD6 on chromosome 6 (Kugathasan, Collins, Maresso, and others, 2004; Ahmad, Armuzzi, Bunce, and others, 2002). The influence of genetics in UC appears to be smaller than in CD; however, the MDRI gene has been associated with UC (Schwab, Schaeffeler, Marx, and others, 2003). Environmental factors appear to play a role in the development of IBD. Breastfeeding decreases the risk of developing CD, whereas infantile diarrhea seems to increase the risk.

Pathophysiology of Ulcerative Colitis

The inflammation is limited to the colon and rectum, with the distal colon and rectum the most severely affected. Inflammation affects the mucosa and submucosa and involves continuous segments along the length of the bowel with varying degrees of ulceration, bleeding, and edema. The presentation may be mild, moderate, or severe, depending on the extent of mucosal inflammation and systemic symptoms. Children with UC usually are seen with diarrhea, rectal bleeding, and abdominal pain, often associated with tenesmus and urgency (Silbermintz and Markowitz, 2006). Thickening of the bowel wall and fibrosis are unusual, but longstanding disease can result in shortening of the colon and strictures. Extraintestinal manifestations are less common in UC than in CD. Toxic megacolon is the most dangerous form of severe colitis.

Pathophysiology of Crohn Disease

The chronic inflammatory process of CD involves any part of the GI tract from the mouth to the anus but most often affects the terminal ileum. The disease involves all layers of the bowel wall (transmural) in a discontinuous fashion, meaning that between areas of intact mucosa, there are areas of affected mucosa (skip lesions). The most common symptoms are abdominal pain, diarrhea, and decrease in appetite resulting in weight loss. Perianal disease, including skin tags, fistulas, and abscesses, occur in CD. Fever, growth delay, and delayed sexual development are seen commonly (Silbermintz and Markowitz, 2006). Mild GI symptoms, poor growth, and extraintestinal manifestations may be present for several years before overt GI symptoms occur. The inflammation may result in ulcerations; fibrosis; adhesions; stiffening of the bowel wall; stricture formation; and fistulas to other loops of bowel, bladder, vagina, or skin. Extraintestinal manifestations include erythema nodosum, pyoderma gangrenosum, arthralgia and arthritis, uveitis and episcleritis, sclerosing cholangitis, autoimmune hepatitis, nephrolithiasis, and pneumonitis (Silbermintz and Markowitz, 2006).

Diagnostic Evaluation

The diagnosis of UC and CD is derived from the history, physical examination, laboratory evaluation, and other diagnostic procedures. Laboratory tests include a CBC to evaluate anemia and an ESR or CRP to assess the systemic reaction to the inflammatory process. Levels of total protein, albumin, iron, zinc, magnesium, vitamin B₁₂, and fat-soluble vitamins may be low in children with CD. Stools are examined for blood, leukocytes, and infectious organisms. A serologic panel is often used in combination with clinical findings to diagnose IBD and to differentiate between CD and UC. In IBD, autoantibodies called antineutrophil cytoplasmic antibodies (ANCAs) may be detected in the blood. The perinuclear antineutrophil cytoplasmic antibody (pANCA) is associated with UC. Approximately 60% of children with UC and 10% of those with CD are pANCA-positive. Anti–Saccharomyces cerevisiae antibodies (ASCA) and anti–outer membrane porin of E. coli (anti-OmpC) have been found in up to 60% of children with CD (Ruemmele, Targan, Levy, and others, 1998).

In patients with CD, an upper GI series with small bowel follow-through assists in assessing the existence, location, and extent of disease. Upper endoscopy and colonoscopy with biopsies are an integral part of diagnosing IBD. Endoscopy allows direct visualization of the surface of the GI tract so that the extent of inflammation and narrowing can be evaluated. CT and ultrasound also may be used to identify bowel wall inflammation, intraabdominal abscesses, and fistulas. CD lesions may pierce the walls of the small intestine and colon, creating tracts called fistulas between the intestine and adjacent structures such as the bladder, anus, vagina, or skin.

Therapeutic Management

The goals of therapy are to (1) control the inflammatory process to reduce or eliminate the symptoms, (2) obtain long-term remission, (3) promote normal growth and development, and (4) allow as normal a lifestyle as possible. Treatment is individualized and managed according to the type and the severity of the disease, its location, and the response to therapy.

Nursing Care Management

The nursing considerations in the management of IBD extend beyond the immediate period of hospitalization. These interventions involve continued guidance of families in terms of (1) managing diet; (2) coping with factors that increase stress and emotional lability; (3) adjusting to a disease of remissions and exacerbations; and (4) when indicated, preparing the child and parents for the possibility of diversionary bowel surgery.

Because nutritional support is an essential part of therapy, encouraging the anorectic child to consume sufficient quantities of food is often a challenge. Successful interventions include involving the child in meal planning; encouraging small, frequent meals or snacks rather than three large meals a day; serving meals around medication schedules when diarrhea, mouth pain, and intestinal spasm are controlled; and preparing high-protein, high-calorie foods such as eggnog, milkshakes, cream soups, puddings, or custard (if lactose is tolerated) (see Feeding the Sick Child, Chapter 22). Foods that aggravate the condition are avoided. Using bran or a high-fiber diet for active IBD is questionable. Bran, even in small amounts, has been shown to worsen the patient’s condition. Occasionally the occurrence of aphthous stomatitis further complicates adherence to dietary management. Mouth care before eating and the selection of bland foods help relieve the discomfort of mouth sores.

When NG feedings or TPN is indicated, nurses play an important role in explaining the purpose and the expected outcomes of this therapy. The nurse should acknowledge the anxieties of the child and family members and give them adequate time to demonstrate the skills necessary to continue the therapy at home if needed (see Critical Thinking Exercise).

The importance of continued drug therapy despite remission of symptoms must be stressed to the child and family members. Failure to adhere to the pharmacologic regimen can result in exacerbation of the disease (see Compliance, Chapter 22). Unfortunately, exacerbation of IBD can occur even if the child and family are compliant with the treatment regimen; this is difficult for the child and family to cope with.