A Framework for Evaluation of the Higher-Risk Infant After a Brief Resolved Unexplained Event

In 2016, the American Academy of Pediatrics published a clinical practice guideline that more specifically defined apparent life-threatening events as brief resolved unexplained events (BRUEs) and provided evidence-based recommendations for the evaluation of infants who meet lower-risk criteria for a subsequent event or serious underlying disorder. The clinical practice guideline did not provide recommendations for infants meeting higher-risk criteria, an important and common population of patients. Therefore, we propose a tiered approach for clinical evaluation and management of higher-risk infants who have experienced a BRUE. Because of a vast array of potential causes, the initial evaluation prioritizes the diagnosis of time-sensitive conditions for which delayed diagnosis or treatment could impact outcomes, such as child maltreatment, feeding problems, cardiac arrhythmias, infections, and congenital abnormalities. The secondary evaluation addresses problems that are less sensitive to delayed diagnosis or treatment, such as dysphagia, intermittent partial airway obstruction, and epilepsy. The authors recommend a tailored, family-centered, multidisciplinary approach to evaluation and management of all higher-risk infants with a BRUE, whether accomplished during hospital admission or through coordinated outpatient care. The proposed framework was developed by using available evidence and expert consensus.

The Characteristics of Esophageal Multichannel Intraluminal Impedance-PH Measurements in Infants Experiencing Brief Resolved Unexplained Events

BACKGROUND

Brief Resolved Unexplained Events (BRUE) is defined as a sudden, brief and now resolved episode characterized by color change, altered respirations, change in tone, and altered level of responsiveness. This study aims to identify the characteristics of esophageal Multichannel Intraluminal Impedance-pH (MII-pH) monitoring in infants who have experienced a BRUE.

METHODS

This study was a retrospective review of records of infants younger than 12 months who presented to the University of South Alabama Children's and Women's Hospital with an admission diagnosis of BRUE. Patients who underwent esophageal MII-pH monitoring between October 2015 and February 2017 and diagnosed with BRUE were initially included in this study.

RESULTS

Fifty-three infants (preterm 25, term 28) who experienced a higher risk BRUE were included in our study. The mean age at diagnosis was 2.25 ± 2.07 months. Apnea (41/53; 77.4%) was the most common manifestation of BRUE. Non-acid reflux events were the most common findings in the MII-pH studies (66%). MII-pH results showed 6/53 (11%) acid reflux, 17/53 (32%) non-acid reflux and 12/53 (23%) both acid/nonacid reflux and 18/53 (34%) were normal. There were significant differences in the longest acid reflux episode and the Reflux Symptom Sensitivity Index (RSSI) of coughing/choking/gagging between preterm and term infants. The Reflux Symptom Index (RSI), RSSI and Reflux Symptom Association Probability (RSAP) were significantly correlated with each other in all symptoms (pain/fussiness, coughing/choking/gagging and vomiting).

CONCLUSIONS

Among infants experiencing a higher risk BRUE, esophageal MII-pH monitoring revealed acid or nonacid reflux in 2/3 of patients.

Clostridium difficile colitis complicating Kawasaki disease in children: Two case reports

Clostridium difficile infection is increasingly diagnosed in children with a wide clinical spectrum ranging from asymptomatic carriage to fulminant colitis. Symptomatic patients typically present with diarrhea, with or without blood, fever, and abdominal pain. Kawasaki disease, a vasculitis of unknown etiology, occurs primarily in young children. Establishing the diagnosis of Kawasaki disease can be challenging given the lack of a confirmatory diagnostic test or pathognomonic features as well as the appearance of symptoms over time rather than simultaneously. In addition, commonly occurring nonspecific associated symptoms, such as diarrhea and abdominal pain, may confound the clinical presentation. We present two cases of children with Kawasaki disease presenting with fever and Clostridium difficile colitis to illustrate the importance of keeping a high index of suspicion for Kawasaki disease.

Short article: The endoscopic and histologic findings of infants who have experienced brief resolved unexplained events

INTRODUCTION

A brief resolved unexplained event (BRUE) describes an event associated with a change in muscle tone, color, respiration, and responsiveness that is unexplained after an appropriate examination. Some infants with higher risk BRUE may undergo endoscopy as part of their evaluation.

OBJECTIVE

This retrospective study aimed to identify the endoscopic findings in infants who have experienced a higher risk BRUE. We also compared the characteristics, prenatal, natal, and postnatal risk factors between 23 infants who underwent endoscopic evaluation and 23 race-matched/sex-matched/term-matched/preterm-matched infants who did not undergo endoscopic evaluation.

METHODS

This was a retrospective descriptive study. Infants were identified from a query of medical records using the ICD-10 code for BRUE (R68.13).

RESULTS

Of 119 infants with BRUE, 23 infants with higher risk BRUE underwent an esophagogastroduodenoscopy and flexible sigmoidoscopy. Apnea (87%) was the most common presentation of BRUE. Most were female (57%) with a mean age at BRUE presentation of 2.73 months. We found 10 (43.5%) term infants and 13 (56.5%) preterm infants in our study. There were no significant differences in characteristics, prenatal, natal, and postnatal risk factors between the infants who underwent endoscopy and those who did not undergo endoscopy. The most common abnormal endoscopic finding was lymphonodular hyperplasia (LNH) associated with eosinophilia in the rectosigmoid colon. The proportion of females in the LNH group was significantly higher than the non-LNH group.

CONCLUSION

Rectosigmoid LNH and eosinophilia, which are associated with milk soy protein intolerance (MSPI), were the most common findings on endoscopic evaluation. Although there is no proof of causation between MSPI and BRUE, MSPI should be considered in the differential diagnosis for higher risk BRUE.

The Relationship between Sleep Disturbance, Quality of Life and Psychosocial Functioning in Pediatric Patients with Inflammatory Bowel Disease

BACKGROUND

Pediatric patients with inflammatory bowel disease (IBD) are at risk for psychiatric symptoms that impact quality of life (QoL) and psychosocial functioning. Sleep disturbance has been reported to impose adverse effects on host defense mechanisms by affecting the magnitude and characteristics of the inflammatory response. The current study sought to assess the relationships among sleep disturbance, QoL, and psychosocial functioning in children with IBD.

METHODS

Pediatric IBD patients completed multiple measures of sleep and daytime functioning as well as measures of QoL and psychosocial functioning. The parents completed complementary measures of sleep, QoL, and psychosocial functioning. The HRQOL results for subjects with IBD were compared to a healthy control group.

RESULTS

Fifty-three children with pediatric IBD and their parents were enrolled in the study. QoL was positively associated with sleep quality, based on significant negative correlations between QoL and both sleep quality and daytime sleepiness scales (r = -0.62, -0.57; p value <0.001, respectively). Patients with CD reported significantly better QoL and psychosocial functioning than patients with UC. The QoL was similar between IBD patients and healthy controls.

CONCLUSIONS

The present study suggests that a positive association exists between sleep functioning and QoL in pediatric patients with IBD. Patients with pediatric IBD should be screened for sleep disturbance, QoL and psychosocial functioning. Prevention and intervention strategies of sleep disturbance aimed at improving QoL and psychosocial functioning in children with IBD should be developed and evaluated.

Correlation of Gastroesophageal reflux disease Assessment Symptom Questionnaire to impedance-pH measurements in children

Background

Esophageal multichannel intraluminal impedance-pH monitoring has become one of the preferred tests to correlate observed reflux-like behaviors with esophageal reflux events. The Gastroesophageal reflux disease Assessment Symptom Questionnaire is a validated tool used to distinguish infants with gastroesophageal reflux disease from healthy children. The aim of this study was to determine whether the Gastroesophageal reflux disease Assessment Symptom Questionnaire composite symptom scores and individual symptom scores correlate with outcomes in esophageal multichannel intraluminal impedance-pH monitoring.

Methods

A total of 26 patients with gastroesophageal reflux disease-associated symptoms, aged 0-2 years, for whom both esophageal multichannel intraluminal impedance-pH monitoring and Gastroesophageal reflux disease Assessment Symptom Questionnaire survey results were available were included in the study. Gastroesophageal reflux disease Assessment Symptom Questionnaire score data were collected from a 7-day recall of parent's responses about the frequency and severity of gastroesophageal reflux disease symptoms, which determined the individual symptom scores. The composite symptom scores is the sum of all individual symptom scores. Multichannel intraluminal impedance-pH study results were compared to Gastroesophageal reflux disease Assessment Symptom Questionnaire data using Pearson correlation.

Results

Among 26 patients, a total number of 2817 (1700 acid and 1117 non-acid) reflux episodes and 845 clinical reflux behaviors were recorded. There were significant correlations between the reflux index and the individual symptom scores for coughing/gagging/choking (r² = 0.2842, p = 0.005), the impedance score and individual symptom scores for coughing/gagging/choking (r² = 0.2482, p = 0.009), the reflux symptom index for acid reflux-related coughing/gagging/choking and the individual symptom scores for coughing/gagging/choking (r² = 0.1900, p = 0.026), the impedance score and individual symptom scores for vomiting (r² = 0.1569, p = 0.045), and the impedance score and the composite symptom scores (r² = 0.2916, p = 0.004). However, there were no significant correlations between fussiness, irritability, or abdominal pain-related multichannel intraluminal impedance-pH results and the individual symptom scores for abdominal pain.

Conclusion

The impedance scores from multichannel intraluminal impedance-pH studies correlate with coughing/gagging/choking and vomiting in infants with gastroesophageal reflux disease. There are no significant correlations among the reflux index and impedance score versus the Gastroesophageal reflux disease Assessment Symptom Questionnaire scores for abdominal pain. We conclude that in infants with gastroesophageal reflux disease, multichannel intraluminal impedance-pH studies are more likely to demonstrate an association between gastroesophageal reflux disease and symptoms of coughing, gagging, or choking compared to an association between gastroesophageal reflux disease and pain in infants.

Association of autoimmune hepatitis type 1 in a child with Evans syndrome

Autoimmune hepatitis (AIH) is a progressive liver disease that is often associated with extrahepatic autoimmune disorders. Evans syndrome (ES) is a rare autoimmune disorder, which is characterized by immune thrombocytopenia and autoimmune hemolytic anemia. Association of AIH with ES is rare, especially in children. We report a 3-year-old female with a past medical history of ES who presented with jaundice and significant transaminitis due to AIH type 1. She required multiple treatments with steroids as well as azathioprine, intravenous immunoglobulin and a course of rituximab.

Brief Resolved Unexplained Events (Formerly Apparent Life-Threatening Events) and Evaluation of Lower-Risk Infants

This is the first clinical practice guideline from the American Academy of Pediatrics that specifically applies to patients who have experienced an apparent life-threatening event (ALTE). This clinical practice guideline has 3 objectives. First, it recommends the replacement of the term ALTE with a new term, brief resolved unexplained event (BRUE). Second, it provides an approach to patient evaluation that is based on the risk that the infant will have a repeat event or has a serious underlying disorder. Finally, it provides management recommendations, or key action statements, for lower-risk infants. The term BRUE is defined as an event occurring in an infant younger than 1 year when the observer reports a sudden, brief, and now resolved episode of ≥1 of the following: (1) cyanosis or pallor; (2) absent, decreased, or irregular breathing; (3) marked change in tone (hyper- or hypotonia); and (4) altered level of responsiveness. A BRUE is diagnosed only when there is no explanation for a qualifying event after conducting an appropriate history and physical examination. By using this definition and framework, infants younger than 1 year who present with a BRUE are categorized either as (1) a lower-risk patient on the basis of history and physical examination for whom evidence-based recommendations for evaluation and management are offered or (2) a higher-risk patient whose history and physical examination suggest the need for further investigation and treatment but for whom recommendations are not offered. This clinical practice guideline is intended to foster a patient- and family-centered approach to care, reduce unnecessary and costly medical interventions, improve patient outcomes, support implementation, and provide direction for future research. Each key action statement indicates a level of evidence, the benefit-harm relationship, and the strength of recommendation.

Gastroesophageal reflux: management guidance for the pediatrician

Recent comprehensive guidelines developed by the North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition define the common entities of gastroesophageal reflux (GER) as the physiologic passage of gastric contents into the esophagus and gastroesophageal reflux disease (GERD) as reflux associated with troublesome symptoms or complications. The ability to distinguish between GER and GERD is increasingly important to implement best practices in the management of acid reflux in patients across all pediatric age groups, as children with GERD may benefit from further evaluation and treatment, whereas conservative recommendations are the only indicated therapy in those with uncomplicated physiologic reflux. This clinical report endorses the rigorously developed, well-referenced North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition guidelines and likewise emphasizes important concepts for the general pediatrician. A key issue is distinguishing between clinical manifestations of GER and GERD in term infants, children, and adolescents to identify patients who can be managed with conservative treatment by the pediatrician and to refer patients who require consultation with the gastroenterologist. Accordingly, the evidence basis presented by the guidelines for diagnostic approaches as well as treatments is discussed. Lifestyle changes are emphasized as first-line therapy in both GER and GERD, whereas medications are explicitly indicated only for patients with GERD. Surgical therapies are reserved for children with intractable symptoms or who are at risk for life-threatening complications of GERD. Recent black box warnings from the US Food and Drug Administration are discussed, and caution is underlined when using promoters of gastric emptying and motility. Finally, attention is paid to increasing evidence of inappropriate prescriptions for proton pump inhibitors in the pediatric population.

Efforts to identify at-risk children for blood lead screening in pediatric clinics--Clark County, Nevada

BACKGROUND

Childhood lead poisoning continues to be a public health problem; however, lead screening rates remain low in many areas. Our objective is to increase screening in pediatric clinics, while testing a questionnaire for its predictability of elevated blood lead levels (BLLs).

METHODS

Participants were approached at pediatric clinics in Las Vegas, Nevada. A brief questionnaire assessed the child's potential exposure to lead and a blood sample was collected from each child.

RESULTS

Of 564 children tested, 35 had detectable BLLs. Two questions from the questionnaire demonstrated significant differences in proportions (Fisher's exact test: P < .05) of affirmative/negative responses, for the 35 participants with detectable BLLs.

CONCLUSION

The questionnaire failed to identify reliable associations between detectable BLLs and affirmative responses, limiting its use as an in-office tool. More research is recommended to identify and alleviate barriers to childhood lead screening in the clinical setting and to develop more applicable risk assessment tools.

Cardiofaciocutaneous syndrome (CFC) with congenital peripheral neuropathy and nonorganic malnutrition: an autopsy study

Many phenotypic manifestations have been reported in cardiofaciocutaneous (CFC) syndrome, but none, to date, are pathognomonic or obligatory. Previous histopathological studies reported findings in skin and hair; no autopsy studies have been published. We report the clinical and autopsy findings of a 7-year-old boy with severe CFC syndrome and malnutrition of psychosocial origin. Manifestations of CFC, reported previously, included macrocephaly and macrosomia at birth; short stature; hypotonia; global developmental delays; dry, sparse thin curly hair; sparse eyebrows and eyelashes; dilated cerebral ventricles; high cranial vault; bitemporal constriction; supraorbital ridge hypoplasia; hypertelorism; ptosis; exophthalmos; depressed nasal bridge; anteverted nostrils; low-set, posteriorly-rotated, large, thick ears; decayed, dysplastic teeth; strabismus; hyperelastic skin; wrinkled palms; keratosis pilaris atrophicans faciei; ulerythema ophryogenes; hyperkeratosis; gastroesophageal reflux; and tracheobronchomalacia. Additional findings, not previously reported, include islet cell hyperplasia, lymphoid depletion, thymic atrophy and congenital hypertrophy of peripheral nerves with onion bulb formations. Although the islet cell hyperplasia, lymphoid depletion, and thymic atrophy are nonspecific findings that may be associated with either CFC or malnutrition, the onion bulb hypertrophy is specific for a demyelinating-remyelinating neuropathy. These findings implicate congenital peripheral neuropathy in the pathogenesis of the developmental delays, feeding difficulties, respiratory difficulties, ptosis and short stature in this case. Additional studies of other cases of CFC are needed.

Age-specific questionnaires distinguish GERD symptom frequency and severity in infants and young children: development and initial validation

Two gastroesophageal reflux disease (GERD) symptom questionnaires were developed and tested prospectively in a pilot study conducted in infants (1 through 11 months) and young children (1 through 4 years) with and without a clinical diagnosis of GERD. A pediatric gastroenterologist made the clinical diagnosis of GERD. Parents or guardians at 4 study sites completed the questionnaires, providing information on the frequency and severity of symptoms appropriate to the 2 age cohorts. In infants, symptoms assessed were back arching, choking or gagging, hiccups, irritability, refusal to feed and vomiting or regurgitation. In young children, symptoms assessed were abdominal pain, burping or belching, choking when eating, difficulty swallowing, refusal to eat and vomiting or regurgitation. Respondents were asked to describe additional symptoms. Symptom frequency was the number of occurrences of each symptom in the 7 days before completion of the questionnaire. Symptom severity was rated from 1 (not at all severe) to 7 (most severe). An individual symptom score was calculated as the product of symptom frequency and severity scores. The composite symptom score was the sum of the individual symptom scores. The mean composite symptom and individual symptom scores were higher in infants (P<0.001 and P<0.05, respectively) and young children (P<0.001 and P<0.05, respectively) with GERD than controls. Vomiting/regurgitation was particularly prevalent in infants with GERD (90%). Both groups with GERD were more likely to experience greater severity of symptoms. We found the GERD Symptom Questionnaire useful in distinguishing infants and young children with symptomatic GERD from healthy children.

Nizatidine for the treatment of pediatric gastroesophageal reflux symptoms: An open-label, multiple-dose, randomized, multicenter clinical trial in 210 children

BACKGROUND

Gastroesophageal reflux disease (GERD), which is reflux that produces damage or troubling symptoms, afflicts approximately 7% of infants and children to the extent that administration of physician-directed pharmacotherapy is warranted.

OBJECTIVE

This study was designed in conjunction with the US Food and Drug Administration (FDA) to assess the tolerability and effectiveness of nizatidine, in different doses and formulations, including a newly formulated premade oral solution, for pediatric GERD.

METHODS

Children aged 5 days through 18 years were recruited to this 8-week, open-label, multiple-dose, randomized, parallel-group, multicenter study. The original study design specified that patients aged 5 days through 12 years at study start be given a nizatidine capsule dissolved in infant formula or apple juice depending on patient age ("extemporaneous solution"). Children 13 through 18 years old were to be given the "adult dose" of nizatidine capsules 150 mg BID regardless of body weight. All patients aged < 13 years were randomized in blocks of 4 between 2 dose levels (2.5 and 5 mg/kg per dose BID). A protocol amendment during the study added a newly formulated, more pediatric-appropriate, premade oral solution that was developed at the request of the FDA. This premade formulation ("oral solution") was to replace the extemporaneous solution mixed in infant formula or apple juice. Subsequently, an additional 44 children aged < 13 years old were enrolled in the study and randomized to receive the new nizatidine oral solution for 8 weeks at the same 2 dose levels as used for the extemporaneous solution. Outcome data at 4 and 8 weeks included adverse events (AEs) (severity, relation to study drug, and any relationship to study withdrawal) and effectiveness (investigators' assessment of changes in reflux symptoms and overall physical well-being, and parent/child assessment of change in antacid use). Formal statistical analyses were not planned, but post hoc chi-square analyses were performed.

RESULTS

Of 214 children enrolled, 210 (98%) intent-to-treat (ITT) patients received > or = 1 dose; of these, 173 (82%) completed 8 weeks of study. At least 77% were compliant (ie, medicated on > or = 75% of days). Of the ITT patients, 37 did not complete 8 weeks due to insufficient response, AEs (regardless of relationship to study drug), or other reasons. Although 292 AEs occurred in 115 patients, 277 (95%) were mild to moderate and 15 (5%) were severe. Most of the AEs in these children studied during the winter were related to infectious illnesses. Only 4 serious AEs occurred; 3 were unrelated to study drug. The fourth AE--considered possibly related--was worsening sickle cell anemia 18 days after medication discontinuation. Approximately 30% of patients became asymptomatic after 8 weeks of treatment, regardless of dosing or formulation, and despite reduction of antacid use in half of the patients. No clear superiority of any dose or formulation was demonstrated.

CONCLUSIONS

This large study, although limited by its open-label design and post hoc analyses, supports the tolerability and effectiveness of 8 weeks of treatment with nizatidine in children aged 5 days through 18 years. AE incidence and severity were as expected for children during the winter season. There was an overall improvement in symptoms and a decrease in antacid use. Formulation did not appear to alter tolerability or effectiveness assessments: the premade solution, extemporaneous solution, and capsule provided comparable symptomatic relief with no disproportionate adverse reactions.

A novel option for dosing of proton pump inhibitors: dispersion of lansoprazole orally disintegrating tablet in water via oral syringe

BACKGROUND

A new formulation of lansoprazole, the lansoprazole orally disintegrating tablet, rapidly disintegrates in water eliminating the need for swallowing whole pills.

AIM

To assess the effect that dispersing the lansoprazole orally disintegrating tablet in water would have on lansoprazole pharmacokinetics.

METHODS

Forty healthy adult men and women (18-43 years) received two single 15 mg lansoprazole orally disintegrating tablet doses separated by 3 days (one administered directly onto the tongue without water and one dispersed in water and administered orally via syringe) in a randomized, crossover fashion. Serial plasma samples were determined from 0 to 12 h for each dose. Ratios of central values for peak plasma exposure (C(max)) and mean overall extent of exposure (area under the plasma concentration) were used to compare the bioavailability.

RESULTS

The two dosing regimens were bioequivalent, with the point estimate for area under the plasma concentration equalling 1.080 (confidence interval 1.012-1.152) and the point estimate for C(max) equalling 1.082 (confidence interval 0.961-1.218).

CONCLUSIONS

Dispersing the 15 mg lansoprazole orally disintegrating tablet in water and administering the dose orally via syringe is bioequivalent to the 15 mg intact lansoprazole orally disintegrating tablet with respect to lansoprazole area under the plasma concentration and C(max). This dosing route provides an additional, convenient dosing option for lansoprazole.

Comparison of fentanyl versus meperidine for analgesia in pediatric gastrointestinal endoscopy

This study compared the safety and efficacy of fentanyl and meperidine for analgesia in pediatric gastrointestinal endoscopy. In a double-blind, randomized trial, 24 patients (11 males) received either fentanyl (1 microg/kg) or meperidine (1 mg/kg). These analgesics were administered in unmarked syringes by an investigator who did not participate in the procedure or in the evaluation of the patient's sedation. There were 17 Caucasians and 7 African-Americans whose mean age was 10.4 +/- 4.4 years. Thirteen patients received meperidine and 11 received fentanyl. Midazolam was given to all patients as needed to provide sufficient sedation for the procedure. Study subjects underwent EGD (n = 17) or colonoscopy (n = 7). There were no differences as assessed by patient, endoscopist, or assistant for tolerance, discomfort, procedure ease, recovery time, complications, heart rate, blood pressure, or oxygen saturation. We conclude that meperidine and fentanyl are equally effective in providing analgesia for pediatric gastrointestinal endoscopy.

Abdominal pain associated with lactose ingestion in children with lactose intolerance

The causal relationship between lactose ingestion and gastrointestinal symptoms is questionable. The aim of this study was to assess symptoms associated with milk ingestion in children with lactose maldigestion. Thirty children (11 males) age 3 to 17 years with lactose maldigestion were studied. In a double-blind, crossover design, subjects ingested 240 mL daily of either lactose-hydrolyzed or lactose-containing milk for 14 days. Diaries were kept daily that recorded diet, medication use, and symptoms. There was a significant increase in abdominal pain experienced by study participants during the lactose ingestion period when compared to the lactose-free period. We conclude that ingestion of 12 g of lactose daily is associated with increased abdominal pain in susceptible children with lactose maldigestion. A trial of dietary lactose restriction may be beneficial in reducing abdominal pain in children with lactose maldigestion.

Ulcerative colitis in children: medical management

Ulcerative colitis is a chronic relapsing inflammatory disorder of the colonic mucosa of unknown etiology. The inflammatory process involves the mucosa and submucosa in a continuous segment of bowel with rectal involvement in almost all cases. Since its etiology is unknown, therapy is directed at modulating the inflammatory response in order to control symptoms and to prevent relapses. 5-aminosalicylates and corticosteroids have been the most widely used therapeutic agents for treatment of ulcerative colitis. Recently, experience has been gained with the use of other immunomodulators, such as mercaptopurine, azathioprine, methotrexate, cyclosporine, and tacrolimus, in pediatric patients. Colectomy is indicated in patients with severe colitis who do not respond to intensive medical therapy. The care of children with ulcerative colitis not only involves control of symptoms from gastrointestinal and extraintestinal manifestations, but also optimizing growth and development. The complications of chronic inflammation and long-term medical therapy must be weighed against the risks and benefits of surgery for children and adolescents with this condition.

Comparison of polyethylene glycol 3350 and lactulose for treatment of chronic constipation in children

Polyethylene glycol (PEG) 3350 and lactulose were compared in an unblinded, randomized, crossover design for treatment of constipation in 37 children aged 2 to 16 years. Subjects received lactulose (1.3 g/kg/d divided twice daily up to 20 g) or PEG 3350 (10 g/m2/day) for 2 weeks. PEG 3350 significantly decreased the total colonic transit time compared to lactulose (47.6+/-2.7 vs 55.3+/-2.4 hours, mean +/- SE, PEG 3350 vs lactulose, respectively, p = 0.038). The stool frequency, form, and the ease of passage were similar for each laxative. Polyethylene glycol 3350 is an effective laxative for the treatment of chronic constipation in children.

Lansoprazole: pharmacokinetics, pharmacodynamics and clinical uses

Lansoprazole (Prevacid, TAP Pharmaceuticals, Inc.) is a substituted benzimidazole that inhibits gastric acid secretion. This agent is approved for the short-term treatment of erosive reflux oesophagitis, active gastric ulcer, active duodenal ulcer and the treatment of non-steroidal anti-inflammatory drug (NSAID)-induced gastric and duodenal ulcers. It is also approved for the long-term treatment of healed reflux oesophagitis, healed duodenal ulcer, the treatment of hypersecretory conditions such as Zollinger-Ellison syndrome and the eradication of Helicobacter pylori as a component of triple therapy with lansoprazole, clarithromycin and amoxicillin, or dual therapy with lansoprazole and amoxicillin. Its mechanism of action is to selectively inhibit the membrane enzyme H+/K+ ATPase in gastric parietal cells. In clinical trials, lansoprazole is more effective than placebo or histamine (H2)-receptor antagonists in the treatment of reflux oesophagitis. Lansoprazole administered at a dose of 30 mg daily produced faster relief of symptoms and superior healing rates in patients with gastric or duodenal ulcers or reflux oesophagitis than H2-receptor antagonists. A daily dose of 30 mg lansoprazole reduced epigastric pain faster than omeprazole 20 mg daily in patients with peptic ulcer disease but healing rates at 4 and 8 weeks were similar with both agents at these dosages. Lansoprazole was more effective than H2-receptor antagonists in patients with Zollinger-Ellison syndrome and produced similar treatment outcome to omeprazole. Lansoprazole in combination with clarithromycin and amoxicillin produced similar rates of eradication of H. pylori. In clinical trials, lansoprazole is well-tolerated and has a low frequency of side effects similar to that of H2-receptor antagonists or omeprazole.

Assessment of hepatic function in cystic fibrosis by lidocaine metabolism

BACKGROUND

To determine hepatic drug metabolism in patients with cystic fibrosis, as measured by monoethylglycinexylidide formation after lidocaine injection and indocyanine green (ICG) clearance.

METHODS

The following study is a case-control study, which included 19 patients with cystic fibrosis and 13 control subjects. Serum monoethylglycinexylidide concentration was measured after intravenous injection of 1 mg/kg (maximum, 50 mg) lidocaine. Indocyanine green (0.5 mg/kg) was injected concomitantly, and absorbance (805 nm) of serum was measured over time to determine its volume of distribution, serum half-life, and hepatic blood flow.

RESULTS

Monoethylglycinexylidide formation was decreased in patients with cystic fibrosis compared with controls (39.4+/-16.9 microg/L versus 70.3+/-45.7 microg/L, mean +/- SD, respectively, P < 0.02). Indocyanine green half-life (4.6+/-2.7 min versus 3.0+/-1.0 min), volume of distribution (8.6+/-5.5 L versus 8.3+/-3.4 L), and hepatic blood flow (10.9+/-5.9 ml x kg(-1) x min(-1) versus 7.4+/-2.0 ml x kg(-1) x min(-1)) were similar in both groups.

CONCLUSION

Monoethylglycinexylidide formation after lidocaine injection is impaired in patients with cystic fibrosis. This impairment may have clinical implications when using hepatically metabolized medications in patients with cystic fibrosis.

The yeast mitochondrial citrate transport protein. Probing the roles of cysteines, Arg(181), and Arg(189) in transporter function

Utilizing site-directed mutagenesis in combination with chemical modification of mutated residues, we have studied the roles of cysteine and arginine residues in the mitochondrial citrate transport protein (CTP) from Saccharomyces cerevisiae. Our strategy consisted of the sequential replacement of each of the four endogenous cysteine residues with Ser or in the case of Cys(73) with Val. Wild-type and mutated forms of the CTP were overexpressed in Escherichia coli, purified, and reconstituted in phospholipid vesicles. During the sequential replacement of each Cys, the effects of both hydrophilic and hydrophobic sulfhydryl reagents were examined. The data indicate that Cys(73) and Cys(256) are primarily responsible for inhibition of the wild-type CTP by hydrophilic sulfhydryl reagents. Experiments conducted with triple Cys replacement mutants (i.e. Cys(192) being the only remaining Cys) indicated that sulfhydryl reagents no longer inhibit but in fact stimulate CTP function 2-3-fold. Following the simultaneous replacement of all four endogenous Cys, the functional properties of the resulting Cys-less CTP were shown to be quite similar to those of the wild-type protein. Finally, utilizing the Cys-less CTP as a template, the roles of Arg(181) and Arg(189), two positively charged residues located within transmembrane domain IV, in CTP function were examined. Replacement of either residue with a Cys abolishes function, whereas replacement with a Lys or a Cys that is subsequently covalently modified with (2-aminoethyl)methanethiosulfonate hydrobromide, a reagent that restores positive charge at this site, supports CTP function. The results clearly show that positive charge at these two positions is essential for CTP function, although the chemistry of the guanidinium residue is not. Finally, these studies: (i) definitely demonstrate that Cys residues do not play an important role in the mechanism of the CTP; (ii) prove the utility of the Cys-less CTP for studying structure/function relationships within this metabolically important protein; and (iii) have led to the hypothesis that the polar face of alpha-helical transmembrane domain IV, within which Arg(181), Arg(189), and Cys(192) are located, constitutes an essential portion of the citrate translocation pathway through the membrane.

Irritable bowel syndrome and lactose maldigestion in recurrent abdominal pain in childhood

BACKGROUND

The aim of this study was to evaluate the impact of irritable bowel syndrome (IBS) and lactose maldigestion in children with recurrent abdominal pain.

METHODS

Children who had abdominal pain associated with defecation or change in bowel habit, disordered defecation, and distension were diagnosed with IBS, and lactose maldigestion was defined by lactose breath hydrogen testing. Children with IBS were managed with increased fiber intake, while those with lactose maldigestion restricted dietary lactose. A telephone survey was conducted to determine the response to treatment.

RESULTS

The mean age of the 59 boys and 87 girls was 9.5 +/- 3.0 years. Children with IBS and lactose maldigestion had more frequent abdominal pain than children without these conditions, but they required less medication for relief of symptoms. CONCLUSIONS. Lactose maldigestion may be a contributory factor in children with IBS, and lactose avoidance in these patients may reduce medication use to relieve symptoms.

Hepatic function as assessed by lidocaine metabolism in sickle cell disease

OBJECTIVE

To evaluate hepatic drug metabolism, as determined by the formation of monoethylglycinexylidide (MEGX) after lidocaine injection and indocyanine green (ICG) clearance, in patients with sickle cell disease.

STUDY DESIGN

A case-control study including 19 patients with homozygous hemoglobin S, and 13 age- and sex-matched black control subjects. Serum MEGX concentration was measured after intravenous injection of 1 mg/kg (maximum 50 mg) lidocaine. ICG (0.5 mg/kg) was injected concomitantly and absorbance (805 nm) of serum was measured over time to determine its volume of distribution, serum half-life, and hepatic blood flow.

RESULTS

MEGX formation at 15 minutes was decreased in patients with sickle cell disease compared with formation in the control subjects (39.9 +/- 18.0 vs 65.6 +/- 50.0 micrograms/L, respectively, p < 0.02). The volume of distribution of ICG was increased in patients with sickle cell disease compared with that in the control subjects (0.21 +/- 0.09 vs 0.11 +/- 0.03 L/kg, p < 0.01). This partly accounts for the decreased MEGX formation. The ICG half-life was similar in both groups (3.8 +/- 1.5 vs 3.1 +/- 1.0 min). Hepatic blood flow, derived from ICG clearance, was increased in sickle cell patients compared with that of the control subjects (12.2 +/- 4.5 vs 8.1 +/- 2.1 ml/kg/min, p < 0.01).

CONCLUSION

Hepatic drug metabolism, as assessed by MEGX formation after lidocaine injection, is impaired in patients with sickle cell disease. This impairment may have clinical implications when using hepatically metabolized medications in patients with sickle cell disease.

Characterization of failure to imbibe in infants

The term failure to imbibe is proposed to describe infants with failure to thrive due to poor feeding. Feeding assessment was performed in 128 patients: 43 healthy controls, 53 diseased controls, 12 with nonorganic failure to thrive, and 20 with failure to imbibe. Infants with failure to imbibe required a significantly longer time to feed compared with other infants. In contrast to other infants with nonorganic failure to thrive, patients with failure to imbibe were more likely to need pediatric subspecialty care and nasogastric or gastrostomy tube feeding. Since these patients may have treatable conditions, infants with failure to imbibe merit further investigation.

Bacterial overexpression of putative yeast mitochondrial transport proteins

Thirty-two genes have been identified within the genome of the yeast Saccharomyces cerevisiae which putatively encode mitochondrial transport proteins. We have attempted to overexpress a subset of these genes, namely those which encode mitochondrial transporters of unknown function, and have succeeded in overexpressing 19 of these genes. The overexpressed proteins were then isolated and tested for five well-characterized reconstituted transport activities (i.e., the transport of citrate, dicarboxylates, pyruvate, camitine, and aspartate). Utilizing this approach, we have clearly identified the yeast mitochondrial dicarboxylate transport protein, as well as two additional lower-magnitude transport functions (i.e., tricarboxylate and dicarboxylate transport activities). The implications of these results and the considerations relevant to this approach are discussed.

Conscious sedation with high-dose midazolam for pediatric gastrointestinal endoscopy

BACKGROUND

Midazolam is used frequently to sedate children for gastrointestinal endoscopy. The sedative dosage of intravenous midazolam commonly reported in children is up to 0.3 mg/kg. We hypothesized that larger doses of midazolam could be used for pediatric endoscopy.

METHODS

We retrospectively reviewed the medical records of 116 pediatric patients (aged 1 year to 18 years) who had endoscopy. The efficacy and side effects of sedation in 45 patients who received midazolam doses of > or = 0.3 mg/kg were compared with the same effects in 71 children who received < 0.3 mg/kg.

RESULTS

All patients received approximately 1 mg/kg meperidine (up to 50 mg) intravenously. The blood pressure, pulse rate, respiratory rate, oxygen saturation, degree and duration of sedation, and incidence of side effects such as hypotension, hypoxia, or vomiting were similar in both groups.

CONCLUSIONS

Intravenous doses of midazolam > 0.3 mg/kg can be used for conscious sedation in children.

Identification of a novel gene encoding the yeast mitochondrial dicarboxylate transport protein via overexpression, purification, and characterization of its protein product

A gene encoding the mitochondrial dicarboxylate transport protein (DTP) has been identified for the first time from any organism. Our strategy involved overexpression of putative mitochondrial transporter genes, selected based on analysis of the yeast genome, followed by purification and functional reconstitution of the resulting protein products. The DTP gene from the yeast Saccharomyces cerevisiae encodes a 298-residue basic protein which, in common with other mitochondrial anion transporters of known sequence and function, displays the mitochondrial transporter signature motif, three homologous 100-amino acid sequence domains, and six predicted membrane-spanning regions. The product of this gene has been abundantly expressed in Escherichia coli where it accumulates in inclusion bodies. Upon solubilization of the overexpressed DTP from isolated inclusion bodies with Sarkosyl, 28 mg of DTP was obtained per liter of E. coli culture at a purity of 75%. The purified, overexpressed DTP was then reconstituted in phospholipid vesicles where both its kinetic properties (i.e. Km = 1. 55 mM and Vmax = 3.0 micro;mol/min/mg protein) and its substrate specificity were determined. The intraliposomal substrates malonate, malate, succinate, and phosphate effectively supported [14C]malonate uptake, whereas other anions tested did not. External substrate competition studies revealed a similar specificity profile. Inhibitor studies indicated that the reconstituted transporter was sensitive to inhibition by n-butylmalonate, p-chloromercuribenzoate, mersalyl, and to a lesser extent pyridoxal 5'-phosphate but was insensitive to N-ethylmaleimide and selective inhibitors of other mitochondrial anion transporters. In combination, the above findings indicate that the identified gene encodes a mitochondrial transport protein which upon overexpression and reconstitution displays functional properties that are virtually identical to those of the native mitochondrial dicarboxylate transport system. In conclusion, the present investigation has resulted in identification of a gene encoding the mitochondrial DTP and thus eliminates a major impediment to molecular studies with this metabolically important transporter. Based on both structural and functional considerations, the yeast DTP is assignable to the mitochondrial carrier family. Additionally, the development of a procedure that enables the expression and isolation of large quantities of functional DTP provides the foundation for comprehensive investigations into the structure/function relationships within this transporter via site-directed mutagenesis, as well as for the initiation of crystallization trials.

Comparison of oral sodium phosphate to polyethylene glycol-based solution for bowel preparation for colonoscopy in children

Thirty-four patients, aged 3 to 17 years, were randomized to receive oral sodium phosphate solution or a polyethylene glycol-based solution in preparation for elective colonoscopy. Nineteen patients received two doses of oral sodium phosphate solution (45 mL/1.7 m2/ dose) and 15 received polyethylene glycol-based solution (4 L/1.7 m2). Compliance with oral sodium phosphate solution was judged as easy or tolerable in 15 of 19 patients, but only in 5 of 15 who were given polyethylene glycol-based solution. The quality of colon cleansing was rated by an endoscopist who was blinded to the colon preparation method used. The bowel preparation was excellent or good (only liquid remaining in the colonic lumen) in 18 of 19 patients who received oral sodium phosphate solution and in 6 of 15 who received polyethylene glycol-based solution. The incidence of vomiting was similar in both groups, but abdominal pain occurred more frequently in the polyethylene glycol-based solution group. Hyperphosphatemia developed in patients who received oral sodium phosphate solution (serum phosphorus = 2.3 +/- 0.7 mmol/L (7.2 +/- 2.2 mg/dL; mean +/- SD), but only in 1 of 15 patients in the polyethylene glycol-based solution group. Patients did not exhibit symptoms of hyperphosphatemia and serum calcium concentrations were similar in both groups. In summary, oral sodium phosphate solution is better tolerated than polyethylene glycol-based solution for bowel preparation in children. However, hyperphosphatemia occurred frequently in patients who received oral sodium phosphate solution. Further studies are needed to determine the optimal dose for safety and efficacy for the use of these solutions in children.

Deletion of the nuclear gene encoding the mitochondrial citrate transport protein from Saccharomyces cerevisiae

The nuclear gene encoding the mitochondrial citrate transport protein (i.e., CTP1) has been deleted from a haploid yeast strain. The stable yeast deletion strain was constructed by homologous recombination of the HIS3 gene at the CTP1 gene locus. Deletion of the CTP was confirmed by PCR. Immunoblot analysis provided the first quantitative estimate of the level of the CTP in wild-type yeast mitochondria and indicated the absence of expressed CTP in mitochondria isolated from the deletion strain. Deletion of CTP1 did not lead to a phenotype on any carbon source tested, indicating that CTP1 is not an essential gene. This suggests that either known alternative pathways are able to produce sufficient acetyl-CoA to support biosynthetic reactions, or there exists a second CTP gene. The ability of the deletion strain to serve as a host for the correct targeting and overexpression of a mutated CTP was then demonstrated. These studies provide a system which permits the use of site-directed mutagenesis to examine both CTP targeting to mitochondria, as well as the molecular basis underlying CTP function. Moreover, this system will not only facilitate the study of the yeast CTP, but also CTPs expressed from the cDNAs of higher eukaryotes.

Symptoms of gastritis due to Helicobacter pylori in children

Infection due to Helicobacter pylori may be associated with gastritis and peptic ulcer disease in children. The aim of this study was to compare the presentation of gastritis due to H pylori with that of gastritis not associated with H pylori infection. The medical records of 296 children who had esophagogastroduodenoscopy were reviewed; 23 (8%) had H pylori gastritis, and 51 had primary gastritis without H pylori infection. Of patients with H pylori, 43% had antral nodularity and 17% had duodenal ulcers. The incidence of epigastric pain, nocturnal pain, postprandial pain, family history of peptic ulcer disease, water brash, vomiting, weight loss, fecal occult blood, and hematemesis was similar between both groups. Periumbilical pain was less common in children with gastritis than epigastric pain, and pain in the periumbilical region was present in only 4% of children with H pylori infection, compared with 31% of patients who had gastritis without H pylori infection. The presence of H pylori should be sought in children having endoscopy for evaluation of upper gastrointestinal mucosal disease.

Effectiveness of nasogastric rehydration in hospitalized children with acute diarrhea

The American Academy of Pediatrics recommends oral rehydration and early refeeding for management of infants with diarrhea and mild to moderate dehydration. However, intravenous rehydration is still widely used for treatment of infants hospitalized for dehydration. The administration of oral rehydration solution via continuous infusion through a nasogastric tube facilitates its delivery in hospitalized children. The purpose of this study is to compare intravenous and nasogastric rehydration in children hospitalized for mild to moderate dehydration. Infants who failed attempts at oral rehydration and were hospitalized for dehydration due to acute diarrheal illness were randomized to receive intravenous or nasogastric rehydration. Following rehydration, infants received soy formula and a maintenance oral electrolyte solution to replace ongoing stool losses, as directed by the attending physician. Patients were discharged from the hospital once oral feeding was tolerated, and the vomiting and diarrhea resolved. Twenty-four patients, from 2 to 19 months of age, were enrolled in the study. Rehydration was successful in 11 of 12 patients in the nasogastric rehydration group and in all 12 patients who received intravenous rehydration. The degree of dehydration, severity of vomiting and diarrhea, and duration of rehydration were similar in both groups. The duration and cost of hospitalization were less for patients receiving nasogastric rehydration compared to those who were rehydrated intravenously. Rehydration by infusion of oral rehydration solution via a nasogastric tube is a safe and effective treatment for infants with mild to moderate dehydration. Rehydration with infusion of oral rehydration solution through a nasogastric tube should be considered for in-patient management of infants with diarrhea.

Lactose maldigestion and recurrent abdominal pain in children

Our objectives were to evaluate children with recurrent abdominal pain for lactose maldigestion and to assess factors which might predict lactose absorption status. One hundred thirty-seven children were referred for specialty evaluation of recurrent abdominal pain of at least three months' duration. Study subjects were evaluated by history and physical examination, dietary interviews, hematologic and biochemical laboratory testing, stool parasite examination, and radiologic or endoscopic structural examinations, as indicated. Lactose hydrogen breath testing was performed after challenge with 1 g/kg lactose 10% aqueous solution). There were 53 males and 84 females, whose ages ranged from 6 to 18 years (9.64 +/- 2.9; mean +/- SD) Lactose maldigestion was detected in 33/137 patients (24%). The prevalence of abdominal pain, bloating, gas, flatulence, diarrhea, and constipation was similar in children with or without lactose maldigestion. The perception of symptoms related to the ingestion of dairy products was similar in both groups. No other clinical parameter predicted lactose maldigestion. However, children with lactose maldigestion had overall clinical improvement with a lactose-restricted diet. Clinical evaluation alone cannot adequately predict the presence of lactose maldigestion in children. Formal evaluation for lactose maldigestion using breath hydrogen testing methods should be considered in children with recurrent abdominal pain.

High level expression and characterization of the mitochondrial citrate transport protein from the yeast Saccharomyces cerevisiae

The gene encoding the mitochondrial citrate transport protein (CTP) in the yeast Saccharomyces cerevisiae has been identified, and its protein product has been overexpressed in Escherichia coli. The expressed CTP accumulates in inclusion bodies and can be solubilized with sarkosyl. Approximately 25 mg of solubilized CTP at a purity of 75% is obtained per liter of E. coli culture. The function of the solubilized CTP has been reconstituted in a liposomal system where both its kinetic parameters (i.e. Km = 0.36 mM and Vmax = 2.5 mumol/min/mg protein) and its substrate specificity have been determined. Notably, the yeast CTP displays a stricter specificity for tricarboxylates than do CTPs from higher eukaryotic organisms. Dot matrix analysis of the yeast CTP sequence indicates the presence of three homologous sequence domains (each approximately 100 residues in length), which are also related to domains in other CTPs. Thus, the yeast CTP displays the tripartite structure characteristic of other mitochondrial transporters. Alignment of the yeast CTP sequence with CTPs from other sources defines a consensus sequence that displays 89 positions of amino acid identity, as well as the more generalized mitochondrial transporter-associated sequence motif. Based on hydropathy analysis, the yeast CTP contains six putative membrane-spanning alpha-helices. Finally, Southern blot analysis indicates that the yeast genome contains a single gene encoding the mitochondrial CTP. Our data indicate that, based on both its structural and functional properties, the expressed yeast CTP can be assigned membership in the mitochondrial carrier family. The identification of the yeast CTP gene, and the expression and purification of large quantities of its protein product, pave the way for investigations into the roles of specific amino acids in the CTP translocation mechanism, as well as for the initiation of crystallization trials.

Effect of pyridoxal 5'-phosphate on the function of the purified mitochondrial tricarboxylate transport protein

The effect of pyridoxal 5'-phosphate (PLP), a lysine-selective reagent, on the function of the purified and reconstituted mitochondrial tricarboxylate transport protein has been studied. PLP caused a concentration-dependent inhibition of citrate transport with an IC50 value of 0.09 mM. At 10 mM PLP virtually complete inhibition of transport was observed (i.e. 97%), thereby indicating that modification of a residue(s) whose participation is essential to the translocation mechanism had occurred. Substrate protection studies demonstrated that substrates for the tricarboxylate transporter (i.e., citrate, isocitrate, phosphoenolpyruvate, and malate) effectively protected against PLP inhibition, whereas other organic anions which are not transported by the tricarboxylate carrier (i.e., malonate, alpha-ketoglutarate, phosphate, and succinate) afforded considerably less protection. Kinetic studies in which the transport rate was measured at varying citrate and PLP concentrations indicated that PLP caused an increase in the apparent Km of transport with little change in the Vmax, thereby resulting in a primarily competitive inhibition pattern. In combination, the above findings indicate that PLP interacts with the tricarboxylate transporter at a site(s) (i.e., a lysine residue(s) and/or the amino-terminal alanine residue) that is important in the translocation mechanism and may reside within or near the substrate binding site.

Sunflower seed bezoar leading to fecal impaction

We report the cases of two children, ages 8 and 10 years, with painful defecation and constipation due to impaction of sunflower seed shells that did not respond to laxative and enema therapy. Physical examination revealed a prickly mass in the rectal vault. Proctoscopy revealed bezoars of sunflower seed shells, which were removed by endoscopic biopsy forceps followed by a combination of rectal irrigation and manual disimpaction. The rectal pain resolved, and bowel habits returned to normal with laxatives. Patients with rectal bezoars who fail to respond to enemas or colonic lavage may require endoscopic management for resolution of their symptoms.

Symptoms of acid-peptic disease in children

Esophagogastroduodenoscopy (EGD) is a useful procedure for the evaluation of gastrointestinal disease in pediatric patients. Indications for EGD in children are similar to those for adults. However, symptoms of acid-peptic disease reported by children may differ from those expressed by adults. Therefore, we sought to identify symptoms associated with acid-peptic disease in pediatric patients. The medical records of 114 children having EGD with biopsy were reviewed. The diagnosis, which included esophagitis, gastritis, duodenitis, ulcer, or normal, was based on histologic findings. Six symptoms correlated significantly with acid-peptic disease: epigastric pain, nocturnal pain, postprandial pain, water brash, weight loss, and a family history of peptic ulcer disease. Epigastric pain and nocturnal pain are the most sensitive symptoms of acid-peptic disease in pediatric patients. Fecal occult blood and hematemesis, although specific, are not sensitive indicators of acid-peptic disease in children.