Lecture 14 Nov 3rd-respiratory

1DDX: LECTURE 14 – NOVEMBER 3rd, 2006 CONDITIONS OF THE RESPIRATORY SYSTEM CONDITIONS OF THE RESPIRATORY SYSTEM: OTHER PNEUMODONIOSIS (X-rays are not diagnostic) • Permanent damage to lung. • Due to inhalation of inorganic dust. Not all dust is a problem. Our immune system responds to some dust inappropriately. Heals with fibrosis. • May be asymptomatic. May not see symptoms until it is a serious pathology. • Problem: masks to protect workers are hot and uncomfortable. Workers remove them. • Progressive dyspnea Conditions are listed in increasing order of seriousness: a) SILICOSIS • Small amount of silica is all that is required for reaction. • Fibrosis pushes on normal tissue, displaces healthy tissue. • Silicosis: get this from sandblasting. • By just looking at x-ray, can’t diagnose silicosis without history. • Can look like infection, but patient has no symptoms. b) ASBESTOSIS • Before asbestos causes mesothelioma, cases asbestosis. • Asbestos is still used in military and space technology • Some say it is better to leave it, not remove it (increased risk when it is airborne in removal) • Engages cell-mediated immunity in lung, pleura c) BLACK LUNG DISEASE • From coal mining • Lung is friable: crumbles, falls apart • Lung filters out coal dust to protect body BERYLLIOSIS AND OTHER VARIANTS see notes SARCOIDOSIS • Idiopathic • Multisystem: see non-caseating (not cheese-like) granulomas. Not like TB • Benight tumours that keep growing and fibrose. Autoimmune disorder. DDX: Erythema nodosum: can happen WITH sarcoidosis. Skin lesions can be confused with many things. Respiratory consequences: look like many pathologies (eg. pneumonia). This diagnosis (sarcoidosis) is often missed! DDX LECTURE 14, NOVEMBER 3rd – PAGE 1

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Peak incidence: 20-40 year olds Granulomas all over the body, through many organs Very debilitating: can take years to recover. Many auto-immune disorders follow other conditions/infections Spontaneous remission in 2-3 years. Easy for pathologist to see what is going on, hard to see clinically.

HYPERVENTILATION SYNDROME • Pontine centre (centre in pons of brain) controls breathing • When something happens that makes you feel endangered, may lose control of breathing. • When you breathe uncontrollably, will ultimately pass out. • Receptors measure pH and CO2. Usually feed info to pons • Salicilate poisoning turns off pontine sensitivity to CO2 and pH. • Sighing: pontine centre does this to try to control breathing. • Sighing may be continuous. • Tetany may occur in late stages (loss of K+?) • Usually once-in-a-lifetime experience (leading to hospitalization). If it happens again, patient knows what is going on, is more calm and can control it better. Case study #2: (We also saw this case on October 25th) Case 2: 58-year old woman with insidious onset chronic cough of 3 month duration. Cough keeps waking her up at night. She is currently unemployed, lives in cooperative housing (subsidized) with boyfriend. She is reliable, interacts well, NAD, W/N Patient does not have any of the following: SOB on exertion, weight loss, fever, diarrhea, anorexia, bouts of confusion or memory loss. She is a smoker (20 packs/year), PND and has 3 pillow orthopnea (has SOB without pillow). Physical exam: Height: 163 cm Weight: 142 lbs BP: 151/98 68 bpm 37.3 C 14 rpm No central/peripheral cyanosis, no clubbing, no delayed capillary refill. No rales bilaterally, she has rhonchi, she has expiratory wheeze, lungs are clear to percussion. (In obstructive conditions, will have difficulty exhaling. In restrictive conditions, difficulty is with inhalation.) (This was a real patient at Anishnawbe) Bothered by waking up at night. Her blood pressure is a red flag. Orthopnea could indicate a cardiac condition PND (paroxysmal nocturnal dyspnea): could be cardiac Smoker: 20 pack-year: could be cancer (½ pack/day is 20 pack-a-year) (?) Chronic cough: could be TB DDX LECTURE 14, NOVEMBER 3rd – PAGE 2

Ddx: CHF, TB, Emphysema, Hypertension, COPD, Bronchiectasis, Cancer While you are in the process of diagnosing, you can treat the most likely diagnosis. Tests? ECG for CHF Lung infection? CBC, sputum culture Skin test and X-ray for TB (it is especially worrisome to see a progression in a TB skin test. Means the disease is progressing. Mantoux test: >5mm is positive.) The pulmonary function test originally diagnosed restrictive, but subsequent test showed obstructive. **It was COPD** Ruled out TB with chest X-ray. 1st TB test was positive, 2nd was negative (mantoux) No solid masses: not cancer. No pneumonia.

EXAM: Will be straightforward. Case-based questions to provide context. History is vital in diagnosis of lung conditions!

DDX LECTURE 14, NOVEMBER 3rd – PAGE 3