What are the Indications for Renal Dialysis?

Patient Presentation
4-year-old male presents to a local emergency room with a 2-day history of watery diarrhea and crampy abdominal pain. Over the past several hours he had some vomiting and had one stool described as liquidy red. The review of systems was negative for fever, rash, joint pain and he has had normal urine output. He was admitted and during his hospital course he continued to have bloody diarrhea, abdominal pain and then developed low-grade fever, hip pain and decreased urine output to 0.2 cc/kg/hour. His physical examination revealed diffuse abdominal pain with active bowel sounds, no organomegaly, no rectal fissures or hemorrhoids, normal musculoskeletal examination and purpura on his upper and lower extremities. His initial laboratory evaluation showed a hemoglobin = 12.4 g/dl, hematocrit = 37%, WBC = 13,000 /mm2, platelets = 300,000 /mm2, electrolytes were normal, BUN = 25 mg/dl and creatinine = 0.7 mg/dl. During his hospitalization his platelets decreased to 70,000/mm2 and his BUN and creatinine rose to 44 mg/dl and 2.2 mg/dl respectively. His potassium rose to 5.3 mEq/l. A clinical diagnosis of hemolytic uremic syndrome (HUS) was made and his stool culture later grew E. coli 0157:H7. He received peritoneal dialysis and had improving renal function at discharge.

Discussion
Diarrhea is the softening of the consistency of the stools with or without a change in the frequency of the stools. Any child may have complications such as dehydration or sepsis because of diarrhea.

Infectious Diarrhea is a common cause of bloody diarrhea. For any individual case of diarrhea, bacterial causes are more likely to have blood associated with them than viral causes. But viral diarrhea is so much more common overall than bacterial diarrhea, that viruses are the most common cause of infectious bloody diarrhea.

Common infectious agents causing bloody diarrhea include:

  • Bacteria – Campylobacter, Clostridium difficile, Salmonella, Shigella, Vibrio cholerae
  • Viruses – Adenovirus, Norwalk virus, Rotavirus
  • Parasites – Ameba, Cryptosporidium, Giardia

HUS is an uncommon but potentially life-threatening cause of diarrhea. Young children, usually 9 months-4 years, begin with a mild gastroenteritis, that overtime becomes a constellation of blood diarrhea, purpura, pallor, hematuria, decrease urine output and possibly renal failure. The children can also have seizures, liver or endocrine abnormalities, and even myocarditis. The laboratory evaluation shows thrombocytopenia, microangiopathic hemolytic anemia, proteinuria and hematuria in the urine, and electrolyte abnormalities including hyperkalemia and elevated BUN and creatinine. The cause in 85% of cases is E. coli 0157:H7. Treatment is mainly supportive with scrupulous fluid and electrolyte management. Red blood cell transfusions are sometimes used but platelet transfusions should be avoided if possible. Other treatments such as antiplatelet drugs or fibrinolytic therapy have not shown benefit. Mortality is 3-5% mainly because of neurological problems. Almost all patients are able to stop dialysis and 60% have full recovery of renal function.

Learning Point
Main indications for renal dialysis include:

  • Oliguria/azotemia
  • Creatinine clearance < 10 ml/min/1.73 M2
  • General symptoms that are worsening, i.e. decreased appetite, emesis/nausea, decreased exercise tolerance/fatigue, poor school performance, growth failure, etc.
  • Nutritional needs that cannot be maintained with necessary fluid restriction
  • Fluid overload
  • Metabolic abnormalities such as uncontrolled hyperkalemia, hyperphosphatemia, hyperuricemia, hypernatremia, hypocalcemia, and severe acidosis or alkalosis
  • Dialyzable toxin

Peritoneal dialysis (PD) and hemodialysis are both options for pediatric patients. Advantages of PD include generally stable serum biochemistries and blood pressure, fewer dietary and fluid restrictions, able to be performed home (if chronic PD), and fewer needs for erythropoietin and blood transfusions. PD is also a good choice for patients with cardiovascular disease or that live far from a dialysis center. It is also easier to perform for small children because of their small size, high rate of thrombosis, and the need for skilled personnel. The main risks of PD are peritonitis and catheter infections.

This patient required transient PD because of oliguria, hyperkalemia, fluid overload and his nutritional needs were not being able to be met because of fluid restriction.

Questions for Further Discussion
1. What public health follow-up is necessary when E. coli 0157:H7 is identified?
2. What other infectious organisms cause HUS?
3. What are the advantages and disadvantages of hemodialysis?
4. What are other non-infectious causes of bloody diarrhea?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Fleisher GR, Ludwig S. Synopsis of Pediatric Emergency Medicine. Williams and Wilkins. Baltimore, MD. 1996.

Rudolph CD, et.al. Rudolph’s Pediatrics 21st edit. McGraw-Hill, New York, NY. 2003.

Woodhead JC. Pediatric Clerkship Guide. Mosby., St. Louis MO, 2003.

Biega T. Prauner R. Hemolytic-Uremia Syndrome. eMedicine.org. Available from the Internet at: http://www.emedicine.com/ped/topic960.htm (rev. 3/4/2004, cited 10/8/04).

Author
Donna M. D’Alessandro, MD
Associate Professor of Pediatrics, Children’s Hospital of Iowa

Date
October 25, 2004

What Follow-Up is Needed for a Borderline Cholesterol Test?

Patient Presentation
A 9-year-old morbidly obese (78 kg) female came to clinic for a minor illness. She had gained 4.5 kilograms in the past 6 months despite receiving dietary counseling by a dietician and had missed follow-up appointments. Interval family history showed that her 50-year-old uncle had died of a myocardial infarction. Her mother also had hypercholesterolemia and was treated with statin medication. The patient had previously been screened for thyroid disease, diabetes, and kidney disease. She had not been tested for hypercholesterolemia. The laboratory evaluation showed a total cholesterol of 175 mg/dL which is borderline.

Discussion
Obesity – About 15% of school age and adolescent children are obese in the U.S. and the number is increasing. A body mass index (BMI) of 85th to 95th percentile for age and sex is considered at risk of overweight, and BMI at or above the 95th percentile is considered overweight or obese. Co-morbid conditions include hypercholesterolemia and dyslipidemia, hypertension, diabetes and impaired glucose metabolism, depression and low self-esteem, obstructive sleep apnea, asthma, pickwickian syndrome, slipped capital femoral epiphysis, steatohepatitis and other conditions. Many of these co-morbidities continue into adult life. Short-term treatment may be effective but long-term outcome is more limited. Therefore prevention is imperative.

Hypercholesterolemia – Lowering cholesterol levels reduces coronary risk factors and mortality in adults. Unfortunately no long-term studies of children’s blood cholesterol and coronary risks are available and children’s risks are inferred. Therefore recommendations for screening are controversial. Currently the American Academy of Pediatrics (AAP) recommends selective blood testing for children > 2 years of age for hypercholesterolemia. Blood testing is recommended based the following risk factors:

  • Parent or grandparent < 55 years with:
    • Coronary atherosclerosis including those who have had balloon angioplasty or coronary artery bypass surgery
    • Myocardial infarction, angina pectoris, peripheral vascular disease, cerebrovascular disease or sudden cardiac death
  • Parent with high cholesterol (>240 mg/dL)
  • Unknown family history

If total cholesterol is acceptable (< 170 mg/dL) then patient should be re-screened in 5 years. If total cholesterol is high (>200 mg/dL) then a complete lipoprotein analysis should be done. If borderline (170-199 mg/dL), then the patient should have another total cholesterol and the results averaged and the patient re-screened based upon this risk. If still borderline or high, a 12-hour fasting analysis should be obtained. This includes total cholesterol, HDL cholesterol and triglycerides. The LDL cholesterol is calculated as: LDL = Total Cholesterol – HDL – Triglycerides. There are other screening variations based upon cardiovascular risk factors that also must be considered.

The mainstay of prevention and treatment of hypercholesterolemia is exercise and nutrition. Children less than 2 years of age should have no restrictions in fat or cholesterol, but healthy normal children 2-18 years should have a diet with

  • Saturated fatty acids <10% of total calories
  • Total fat between 20-30% of total calories
  • Cholesterol <300 mg per day

For reference, 1 egg has about 200 mg of cholesterol, 1 hamburger patty or 1 cup of whole milk has about 40% total calories from fat.

Learning Point
According to the American Academy of Pediatrics (AAP) current policy statement, the patient’s borderline total cholesterol needs to be re-checked. The two test numbers should be averaged and if still borderline or high, a 12-hour fasting analysis should be obtained. Because of the patient’s premature cardiac disease the patient should have had the fasting tests initially. Fasting tests could not be done as her appointment was in the late afternoon and the doctors were concerned with follow-up. They opted for the total cholesterol only. The patient’s obesity itself requires intensive nutritional management but for hypercholesterolemia alone therapeutic diets called Step-One and Step-Two diets are recommended. Drug therapy is only recommended for children older than 10 years.

Questions for Further Discussion
1. What national organizations besides the AAP have for cholesterol screening recommendations for children?
2. How do these recommendations different from the American Academy of Pediatrics?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Information prescriptions for patients can be found at Pediatric Common Questions, Quick Answers for this topic: Obesity.

American Academy of Pediatrics Policy Statement. Cholesterol in Childhood. Pediatrics 1998:101;141-147. Available from the Internet at: http://aappolicy.aappublications.org/cgi/content/full/pediatrics%3b101/1/141 (cited9/30/04).

American Academy of Pediatrics Policy Statement . Prevention of Pediatric Overweight and Obesity. 2003:112;424-430. Available from the Internet at: http://aappolicy.aappublications.org/cgi/content/full/pediatrics;112/2/424?fulltext=obesity&searchid=QID_NOT_SET (cited10/4/04).

Gebhardt, Susan E., and Robin G. Thomas. 2002. Nutritive Value of Foods. U.S. Department of Agriculture, Agricultural Research Service, Home and Garden Bulletin 72. Available from the Internet at: http://www.nal.usda.gov/fnic/etext/000020.html (cited 10/4/04)

Author
Donna M. D’Alessandro, MD
Associate Professor of Pediatrics, Children’s Hospital of Iowa

Date
October 18, 2004

Which Infants Need RSV Prophylaxis?

Patient Presentation
A 62-day-old female infant born at 29 2/7 weeks gestation comes to the outpatient clinic for a weight check after discharge 5 days ago in July. Her weight is up 56 grams on 24 calories/ounce premie formula. Her past medical history was complicated by intubation for 1 week and nasal canula oxygen for another 3 weeks. She had no apnea and bradycardia including when placed into a car seat prior to discharge. She also had neonatal jaundice that resolved within 1 week. Her hearing screening and head ultrasound were normal. Her retinal exam reveals vascularization that is normal to zone 3 but needs to be followed at least once more by ophthalmology. The pertinent physical findings reveal a normal, healthy, almost term infant. Her mother asks if she is a candidate for Respiratory Syncytial Virus (RSV) prophylaxis.

Discussion
Once discharged, the services and procedures needed for comprehensive premature infant follow-up are varied because of individual differences in gestation age at birth, weight, medical conditions and hospital course. Healthcare providers should review the patient’s chart to see if the following common tests and procedures were considered, completed or planned:

  • Universal metabolic screening

  • Universal hearing screening
  • Retinopathy of Prematurity (ROP) ophthalmologic exam
  • Developmental assessment
  • Head ultrasound for possible intracranial bleeding
  • Echocardiogram for possible patient ductus arteriosis
  • Nutritional assessment and plan
  • Immunizations
  • Car seat screening for apnea

Many other tests and procedures may have been evaluated or need to be evaluated depending on the individual circumstances.

RSV can cause pneumonia and bronchiolitis in infants and the morbidity and mortality can be especially high in premature infants. Prophylactic medication is available and should be given to those susceptible. Because of the medication cost, delivery methods and individual infant risk, guidelines are generally used to determine which medication should be given. Currently at the Children’s Hospital of Iowa, infants with chronic lung disease less than 1 year of age receive RespiGamTM (RSV immunoglobulin) monthly by IV infusion. The RespiGam should be started at the onset of RSV season and continued until the end of the season. SynagisTM is a monoclonal antibody. It is given as an intramuscular injection. Infants less than 2 years of age on home oxygen therapy or who have stopped therapy within 2 months of RSV season should be considered for Synagis. Also any infant who was born less than 28 weeks gestation and is less than 6 months of age during RSV season should be considered for monthly Synagis to begin at the onset of RSV season and continued until the end of the season. Infants born at or before 32 weeks gestation discharged during RSV season also should be given one injection prior to discharge. Other infants may be considered for RespiGam or Synagis depending on their individual circumstances.

Learning Point
This patient was not a candidate for prophylactic RSV medication according to these current guidelines because of gestation and chronological age. She was also not on home oxygen and it is not RSV season. These guidelines may change and need to be reviewed at least yearly. This patient had appropriate screening evaluations done during her hospital stay and during this visit she was given her 2-month immunizations. In the future she would be changed to standard formula once she reaches 40 weeks corrected gestation and will not need the additional nutritional supplementation offered in premature infant formulas. She will also be changed to 20 calories/ounce formula when she has continued appropriate weight gain.

Questions for Further Discussion
1. What is the therapy for premature and other infants with RSV who are hospitalized?
2. What is the categorization of ROP?
3. How does oxygen therapy relate to ROP and Bronchopulmonary Dysplasia (BPD)?

Related Cases

To Learn More
To view pediatric review articles on this topic from the past year check PubMed.

Information prescriptions for patients can be found at Pediatric Common Questions, Quick Answers for this topic: Respiratory Syncytial Virus (RSV).

Iowa Neonatology Handbook. University of Iowa. Available from the Internet at: http://www.vh.org/pediatric/provider/pediatrics/iowaneonatologyhandbook/index.html (rev. 12/04, Cited 8/30/04)

Sherman MP, Steinfeld MB, Phillips AF, Shoemaker CT. Follow-up of the NICU Patient. Available from the Internet at: http://www.emedicine.com/ped/topic2600.htm (rev. 2/02, cited 8/30/04)

American Academy of Pediatrics Committee on the Fetus and Newborn. “Hospital Discharge of the High-Risk Neonate – Proposed Guidelines,” Available from the Internet at: http://aappolicy.aappublications.org/cgi/content/full/pediatrics;102/2/411 (rev. 1998, cited 9/16/04)

Author
Donna M. D’Alessandro, MD
Associate Professor of Pediatrics, Children’s Hospital of Iowa

Date
October 11, 2004