Pediatric Respiratory (CF)

CYSTIC FIBROSIS (CF) Overview

  • A genetic disorder caused by defects in the CFTR gene.

  • Affects multiple organs, including lungs and pancreas.

  • Associated conditions: Gastroparesis.

CYSTIC FIBROSIS: Gene Definition

  • Gene Defect: Located at chromosomal position 7q31.

  • Defective Regulation: Affects the regulation of inorganic ion transport.

PATHOPHYSIOLOGY of CYSTIC FIBROSIS

  • Characterized by abnormal exocrine function due to defective ion transport.

  • Impact on various glands:

    • Serous Glands: Result in sticky, concentrated secretions.

    • Secretory Glands: Produce mixed electrolyte and macromolecular secretions including mucus in sweat, salivary and pancreatic glands.

    • Ducts: Experience obstructions leading to patchy duct obstruction or fibrosis, particularly in:

      • HEPATOBILIARY SYSTEM.

      • LUNGS.

      • INTESTINE.

      • REPRODUCTIVE SYSTEM.

  • Consequences of the pathology:

    • Marked fibrosis due to defective chloride channels.

    • Duct obstruction and focal biliary cirrhosis with altered bile salt metabolism.

    • Normal at birth but develops into various obstructive complications:

      • Small airway obstruction in lungs resulting in recurrent infections.

      • Distal bowel obstruction in the gastrointestinal tract (neonatal gut obstruction).

      • Growth issues such as malnutrition and anorexia.

Genetics & Prevalence

  • Inheritance Pattern: Autosomal recessive trait.

  • Prevalence:

    • More than 75% are diagnosed by age 2.

    • More common in the white population, approximately 3%.

CYSTIC FIBROSIS SCREENING

  • Diagnostics & Lab Tests:

    • PRENATAL DIAGNOSTICS/SCREENING:

      • Carrier screening for prenatal planning.

      • Amniocentesis and chorionic villus sampling (CVS) for direct testing.

    • NEWBORN SCREENING:

      • Heel prick test using a Guthrie card.

    • DIAGNOSTICS:

      • Sweat Chloride Test: Identifies chloride levels in sweat.

      • DNA Testing: Identifies specific CFTR mutations.

      • SYSTEM-SPECIFIC TESTING:

      • Pulmonary Function Tests.

      • Chest X-ray and Abdominal X-ray.

      • Duodenal analysis.

    • LAB TESTS: Assessment of blood levels of fat-soluble vitamins.

CYSTIC FIBROSIS: How it Affects the Body

  • Multiple systems impacted leading to various symptomatologies:

    • Respiratory Findings:

      • Progressive symptoms: Intercostal retractions, use of accessory muscles, barrel chest deformity, digital clubbing, cyanosis, declining exercise tolerance.

      • Complications: Pneumothorax, nontuberculous mycobacterial infections, hemoptysis, allergic bronchopulmonary aspergillosis (ABPA), and right heart failure due to pulmonary hypertension.

      • Cough and sputum production.

      • Upper respiratory involvement: Nasal polyps, chronic rhinosinusitis.

  • Gastrointestinal Findings:

    • Meconium ileus may be the earliest sign of CF.

    • Symptoms include:

      • Malnourishment, failure to thrive, delayed growth, distended abdomen, deficiencies in vitamins A, D, E, K.

      • Pancreatic insufficiency leading to steatorrhea (oily stools).

      • Other complications: Intussusception, rectal prolapse, gastroesophageal reflux disease (GERD), gastroparesis.

  • Integumentary Findings:

    • Sweat, tears, and saliva show high levels of Na+ and Cl- content.

  • Endocrine & Reproductive Findings:

    • Decreased insulin production leading to Cystic Fibrosis Related Diabetes (CFRD).

    • Delayed sexual development and irregular menstruation in females.

    • Viscous cervical mucus and decreased or absent sperm production in males.

PULMONARY MANAGEMENT

  • MEDICATIONS:

    • Use of inhaled/nebulizer treatments to liquify secretions and stimulate cough.

    • Common medications include:

      • Dornase Alfa (Pulmozyme).

      • Hypertonic Saline (7%), Albuterol.

      • Antibiotics and antifungals (oral/aerosol/IV).

      • O2 therapy.

      • Ibuprofen.

      • CFTR modulators like Ivacaftor.

  • AIRWAY CLEARANCE THERAPY (ACT):

    • Techniques involve various airway segments in order to clear mucus effectively.

    • Incorporating aerobic exercises as part of daily management.

  • NUTRITIONAL MANAGEMENT:

    • Patients may require up to 200% of the Recommended Dietary Allowance (RDA) for growth.

    • Dietary strategies include:

      • Water-soluble forms of vitamins A, D, E, K.

      • No need for fat restriction; just increased enzyme intake.

      • Added dietary salt during excessive sweating and hot weather.

      • Pancrealipase enzyme preparations with enteric coatings for effective digestion.

      • Goal: Reduce daily stools to 1-2/day; constipation may be treated with MiraLAX.

ENDOCRINE MANAGEMENT

  • Focus on monitoring for diabetes:

    • Target HgA1C testing and check for microvascular complications.

    • Insulin is the only recommended treatment for diabetes management.

  • Monitoring bone health due to growth hormone issues and vitamin D deficiencies during CF management.

  • Possible use of recombinant human growth hormone (rhGH) for treatment if indicated.

CYSTIC FIBROSIS: Goals of Care

  • Aim for normalization of daily activities and peer involvement.

  • Access to support groups and resources for emotional needs and caregiver support.

  • Encourage development of independent and active children.

SUPPORT AND EDUCATION

  • Comprehensive education on:

    • Diet and strategies to increase caloric intake.

    • Proper medication use and safety.

    • Airway clearance therapy (ACT) and chest physiotherapy (CPT).

    • Importance of up-to-date immunizations.

    • Referrals for genetic and reproductive counseling.

REFERENCES

  • Merck Manual - Pediatrics: Cystic Fibrosis Overview.

  • Cystic Fibrosis Foundation website.

  • Wong’s Essentials of Pediatric Nursing, 11th ed.

  • Additional educational resources and articles listed in the transcript for further reading.