{"id":2150,"date":"2009-12-31T15:53:55","date_gmt":"2009-12-31T20:53:55","guid":{"rendered":"http:\/\/insidesurgery.com\/?p=2150"},"modified":"2009-12-31T16:52:40","modified_gmt":"2009-12-31T21:52:40","slug":"cystic-fibrosis","status":"publish","type":"post","link":"https:\/\/insidesurgery.com\/2009\/12\/cystic-fibrosis\/","title":{"rendered":"Cystic Fibrosis"},"content":{"rendered":"
Pathophysiology<\/strong><\/p>\n 1)<\/strong> cause is impaired action of the chloride channel in epithelial cells 2)<\/strong> hallmarks are the varying sequelae of inspissated mucus in the visceral organs, including lungs, exocrine pancreas, liver, and reproductive tract<\/p>\n Signs and Symptoms<\/strong><\/p>\n Lungs<\/em> – 1)<\/strong> recurrent bronchiolitis, bronchitis, and bronchiectasis 2)<\/strong> cough 3)<\/strong> tenacious sputum 4)<\/strong> shortness of breath Pancreas<\/em> – 5)<\/strong> blocked exocrine ducts with chronic pancreatitis\/fibrosis 6)<\/strong> steatorrhea Liver <\/em>– 7)<\/strong> focal biliary cirrhosis, sequelae of end-stage liver disease 8)<\/strong> some newborns with perinatal obstructive jaundice GI tract<\/em> – 9)<\/strong> retention of meconium past perinatal period (5%-10%) Reproductive tract<\/em> – 10)<\/strong> fibrosis of seminal vesicles, vas deferens, and epididymis (98% male infertility)<\/p>\n Characteristic Test Findings<\/strong><\/p>\n Laboratory<\/em> – 1)<\/strong> diagnosis is by chloride sweat test with increased Cl- ions 2)<\/strong> increased serum IL-8, causing massive cellular destruction<\/p>\n Histology\/Gross Pathology<\/strong><\/p>\n 1)<\/strong> abnormally thick mucous in lumina of lungs, pancreas, bile ducts, and fetal intestine 2)<\/strong> pancreas becomes almost completely cystic with fibrosis (hence the term cystic fibrosis)<\/p>\n Associated Conditions<\/strong><\/p>\n 1)<\/strong> lung infections with Staph, Pseudomonas (virtually diagnostic for cystic fibrosis) and Burkholderia cepacia (high mortality) 2)<\/strong> deficiency in fat-soluble vitamins (A, D, E, K)<\/p>\n Biochemistry<\/strong><\/p>\n 1)<\/strong> lack of chloride secretion in pancreas is related to abnormal sodium and water secretion, making intraductal secretions very viscid 2)<\/strong> cystic fibrosis gene encodes for cystic fibrosis transmembrane conductance regulator (CFTR) 3)<\/strong> 400 different alleles are known to cause cystic fibrosis, with four different classes of defects 4)<\/strong> classes I and II – more severe and usually have pancreatic insufficiency 5)<\/strong> classes III and IV – less severe and usually have preserved pancreatic exocrine function<\/p>\n Inheritance\/Epidemiology<\/strong><\/p>\n 1)<\/strong> autosomal recessive 2)<\/strong> defect is on 7q31.2 3)<\/strong> occurs in 1\/2500 newborns in USA (95% in whites) 4)<\/strong> 1\/25 of white population is heterozygous for cystic fibrosis 5)<\/strong> 15% of adolescents and 10% of adults have significant liver disease 6)<\/strong> 50% of meconium ileus patients develop perforation\/peritonitis, intestinal atresia, or volvulus<\/p>\n Treatment<\/strong><\/p>\n 1)<\/strong> postural drainage and respiratory therapy 2)<\/strong> nebulized antibiotics (especially tobramycin) 3)<\/strong> exogenous pancreatic enzymes 4)<\/strong> bronchial artery embolization in hemoptysis 5)<\/strong> meconium ileus – enema with hypertonic agent with detergent (Gastrograffin works well); if enema fails,surgery with mechanical evacuation of bowel 6)<\/strong> some improvement in prognosis has been reported with long-term azithromycin, cyclosporin, IV immunoglobulin, leukotriene antagonists, ibuprofen, or megestrol<\/p>\n Tips for USMLE<\/strong><\/p>\n 1)<\/strong> diagnosis is via chloride sweat test 2)<\/strong> if question mentions lung infection with Pseudomonas or Burkholderia cepacia, think cystic fibrosis 3)<\/strong> for all meconium ileus in newborns, think cystic fibrosis<\/p>\n","protected":false},"excerpt":{"rendered":" Pathophysiology 1) cause is impaired action of the chloride channel in epithelial cells 2) hallmarks are the varying sequelae of inspissated mucus in the visceral organs, including lungs, exocrine pancreas, liver, and reproductive tract Signs and Symptoms Lungs – 1) recurrent bronchiolitis, bronchitis, and bronchiectasis 2) cough 3) tenacious sputum 4) shortness of breath Pancreas […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_exactmetrics_skip_tracking":false,"_exactmetrics_sitenote_active":false,"_exactmetrics_sitenote_note":"","_exactmetrics_sitenote_category":0,"_genesis_hide_title":false,"_genesis_hide_breadcrumbs":false,"_genesis_hide_singular_image":false,"_genesis_hide_footer_widgets":false,"_genesis_custom_body_class":"","_genesis_custom_post_class":"","_genesis_layout":"","footnotes":""},"categories":[63],"tags":[804,806,808,802,807,805,803],"yoast_head":"\n