MX1002-PAS-Wk7-RSThe only place wheresuccess comes beforework is in a dictionary…!Vidal Sassoon
MX1002-PAS-Wk7-RSPathophysiologyRespiratory SystemDr. Venkatesh M. Shashidhar.Associate Professor & Head of Pathology
PAS-Respiratory PathophysiologyIntroduction to Resp. Sys:• 10,000L/day of air – filtered, moistened,warmed, O2/Co2. exchanged.!• Full capacity 6L. (500ml at rest)• Sinusitis, pharyngitis, laryngitis…* URI• Pneumonia: Inflammation of lung * LRI• Chronic: COPD, Fibrosis – Smoking.• Commonest internal Cancer.• Respiratory tract inflammations -commonest in medical practice.• Enormous morbidity & mortality.• Important medical learning. Doctors daily bread….!
PAS-Respiratory PathophysiologyLobar Pneumonia - Primaryin healthy people in community. Gram Positive Cocci, wholelobe unilateral. heals without scar. Rare complications.
PAS-Respiratory PathophysiologyBronchopneumonia - Secondaryin Sick patients, Gram Negative bacilli, bilateral,basal. More complications, heals by scarring.
PAS-Respiratory PathophysiologyBroncho-pneumonia – Lobar-pneumonia• Extremes of age.• Secondary, in sick.• Both genders.• Klebsiella, E.coli• Patchy, basal, bilateral.• Around Small Bronchi• Not limited by anatomicboundaries.• Usually bilateral.• Middle age – 20-50• Primary in a healthy adult.• males common.• 95% pneumococcus• Entire lobe consolidation• Diffuse• Limited by anatomicboundaries.• Usually unilateral
PAS-Respiratory PathophysiologyRestrictive vs Obstructive• Interstitial fibrosis• Stiff hard lung• Increased tissue• Normal FEV1:FVC ratio• Normal PEFR.• Types:– Fibrosis,– Pneumoconiosis• Obstruction to air flow.• Soft lung• Loss of tissue.• Low FEV1:VC ratio• Low PEFR.• Types:–COPD–Asthma
MX1002-PAS-Wk7-RS“Get me well so I can get ontelevision and tell people tostop smoking…!”-- Nat King Cole
“Troubles are often the tools by whichnature fashions us for better things”- Henry Ward Beecher
Life’s battles don’t go always to the stronger orfaster man, sooner or later, The man who wins isthe man who thinks he can….!
MX1002-PAS-Wk7-RSPathology ofLung tumors(Lung Cancer)Dr. Venkatesh M. ShashidharA/Prof. & Head of PathologySchool of Medicine45
PAS-Respiratory PathophysiologyLung Cancer Intro:• Most common & fatal cancer (internalmalignancy)• Kills more people than colorectal,breast, and prostate cancers combined.• Significant increase in incidence..(developing countries*)• Now Increasing in females > breastcancer.• 90% of lung cancers are related tosmoking..! (passive smoking in 5%)• Mutagen sensitive genotype : P-450enzyme• Poor prognosis ~ 5% 5y survival *46
PAS-Respiratory PathophysiologyLung Cancer Incidence:47
PAS-Respiratory PathophysiologyLung Cancer & Smoking:• Proportional to duration, amount & quality of smoking &deep inhaling.• 90% are smokers and 10% are non smokers• 20 fold risk if >40cigarettes per day• >100 fold combined with Asbestos, coal, radon, etc.• Atypical cells in sputum in 96.7% of smokers - 0.9% in nonsmokers.• Smoke has several irritants & carcinogens.– Initiators – Benzo[o]pyrenes– Promoters – Phenol derivatives– Radioactive substances – Polonium, C14, K4048
PAS-Respiratory PathophysiologyCushing’s syndrome in SCC61Paraneoplastic syndrome:• Tumour producing ACTH hormone.• Excess adrenal glucocorticoids.• Central obesity, diabetes etc..
PAS-Respiratory PathophysiologyMesothelioma:• Tumor of Pleural covering.• Asbestosis – risk factor.• Poor prognosis• 50% mortality in first year.62
Bernie BantonAsbestosis victim died Aug 2007.Had Asbestosis, asbestos-related pleuraldisease (ARPD),stomach cancer & Peritoneal mesothelioma.He became the face of the fight to getcompensation for affected workers and wonhis final victory less than a week before hisdeath..!.Mr Banton was awarded Order of Australia.“until they put me in the box, Ill be out there fighting…!".-- Bernie Banton, in his speech to ABC.Commitment always wins….!
PAS-Respiratory PathophysiologyClinical Case 1:A 28y Indonesian student presents with weight loss over a four-month period and the recent onset of fever and chills at night.Had several courses of antibiotics from his GP withoutimprovement. Admission chest x-ray revealed an irregular opacityof the right apical lobe of lung with pleural effusion. Clinicalexamination revealed cervical and axillary lymphadenopathy.What is the likely problem? Chronic, infection, TB.country of origin? Epidemiology.What further tests? Bacterial culture, biopsy, PCR.What is the prognosis? resistant, imm, risk factors.64Tuberculosis
PAS-Respiratory PathophysiologyClinical Case 2:• An 18y student from Tully, presented with wheezing anddifficulty in breathing. These attacks occurredintermittently since childhood worse during winter. An x-ray of the chest was normal, but lung function testsduring attack demonstrated a markedly decreasedFEV1, which improved significantly after he inhaledbronchodilator. The patient was prescribedbronchodilator & steroid inhalers which some relief, butthe patient continued to experience episodes ofbreathlessness in the coming years.• What is the likely problem? Chronic, recurrent, seasonal• Why many attacks ? hypersensitivity/allergy.• What is the prognosis? Nature, preventive only.65Asthma
PAS-Respiratory PathophysiologyClinical Case 3:• A 41y man was brought to emergency with high fever, shaking chills,coughing up rusty sputum. On history, hed been fine the day beforebut that morning he had begun to shake uncontrollably and feltalternately cold then hot and sweaty. His chest hurt on breathing. Onexamination, thin white male who was anxious and mildly cyanotic,tachypnea, fine rales and decreased breath sounds by auscultationover the right lower chest. Temp100.2°F, but his pulse was normal.WBC high, with 70% polys, 18% bands, and 12% lymphocytes.Blood gases hypoxia & respiratory alkalosis. sputum gram-positivediplococci.• What is the problem? Acute infection of lungs – pneum.• What & Why is he cyanotic? Co2 excess. Gas exch.• Fine rales over RLL? Fluid – lobar pneumonia.• Why his WBC count is high? – Acute inflammation.• Gram Positive Diplococci ? – common, Strep. pneumoniae.66Pneumonia
PAS-Respiratory Pathophysiology“A good scare is worth more toa man than good advice."- Edgar Watson Howe - Country Town Sayings (1911)That’s why we haveExams!
PAS-Respiratory PathophysiologyLearning Objectives:• Respiratory anatomy, upper & lower resp. tracts.• Review the process of ventilation & respiration.• Pulmonary function tests (FVC, FEV1, FEV1/VC)• Overview of chest radiograph & imaging.• Respiratory infections - pneumonia and TB.• Overview of obstructive and Restrictivepulmonary disorders, Asthma, COPD, Fibrosis.• Describe respiratory failure and its causes *• Lung cancer, etiology, types and features.68