lecture 6? airway injury following lung transplantation Flashcards
how does survival change after lung transplant?
- less early mortality
- long term survival is around 7 years after transplant
why does survival after lung transplant decline faster?
- constantly exposed to environment
- vulnerable to pathogens inhaled etc.
what is chronic lung allograft dysfunction (CLAD)?
- narrowing of bronchiolar lumen by fibrous tissue
- chronic rejection
how many recipients develop CLAD within 3 years?
- 50%
- no improvements over last decade despite improving medicines
how does FEV1 change after transplant?
- shows overall deterioration
- fixed airflow limitation
what does this decreasing FEV1 after transplant lead to?
- bronchiolitis obliterans syndrome
what is brochiolitis obliterans syndrome?
- chronic lung allograft dysfunction
- affects majority of lung transplant recipients
what are the characteristics of BOS?
- dyspnea (shortness of breath)
- persistent progressive cough
- wheezing
- fatigue
what pathology underlies BOS?
- obliterative bronchiolitis (inflammatory cell fibrosis)
- blockage of airways so no air flow to lungs
how does the response to injury lead to BOS?
- rejection due to aspiration/ infection
- neutrophil production to protect
- epithelial damage occurs
- causes airway remodelling
- fixed airway obstruction
what is airway remodelling?
- change in structure and airflow of the lungs
what methods are used to diagnose and test for BOS?
- flexible fibrotic bronchoscopy
- bronchioalveolar lavage
what is a biopsy?
- small amount of tissue taken for analysis and diagnosis
what is a bronchialveolar lavage?
- minimally invasive procedure
- tests for lung disease
- bronchoscope passed through mouth or nose
- measured amount of fluid collected for examination
what does aspiration of reflux cause?
- pneumonia
what can occur during lung transplantation?
- chest openend
- possibility of vagal nerve damage
- gastroparesis slowing down gastric emptying
- blunted cough and clary clearance mechanisms
what is the function of vagus nerve?
- emptying of GI system
what are the methods of treatment for the allograft damage?
- proton pump inhibitors
- surgical fundoplication
what is pH-impedence?
- catheter going down the oesophagus
- liquid goes up from stomach as it would in reflux event
- change in electrical resistance across bands on catheter
- data recorded to measure travel and reflux events in 24hours
what is pepsin?
- gastric acid protease
- proteolytic activity
- can be used as a marker of aspiration
what does pepsin show?
- high pepsin present in all lung diseases
- acute lung disease has highest levels of pepsin
what is the correlation between GORD and lung injury?
- the more reflux that occurs, the more neutrophils present
- highlights infection
how does the microbiome link to gastric juice?
- bacteria including pseudomonas was found in gastric juice of patients with more alkaline pH of 5-8
