Module 12 The Respiratory System Flashcards

Question

Hyper reactive airways disorder What is it? What are the causes? Characterised by? https://www.youtube.com/watch?v=bm6iQpSzhO4

Answer 1

A reversible underlying state of hyper-reactivity. an airway that responds both too much and too easily to various stimuli Often those diagnosed with asthma are simply suffering HRA. Causes include 1. neural mechanisms, 2. immune deficiency, 3. infection and 4. inflammation. Characterised by? * This disease is characterized by the following symptoms: * Bronchial irritability – to many non-specific stimuli * Nocturnal dyspnea * Morning tightness for longer than one hour * Due to current exposures o eg.Seasonalallergens,dustmites,exercise,viralinfections o Removal of environmental stimulus improves the inflammation and hyperresponsiveness

Answer 2

Bronchoconstriction mediated by parasympathetic nerves (vagus). Bronchodilation is a result of sympathetic stimulation of airway smooth muscle. * Structural and physiological airway changes (airway remodeling) * Has been thought to be related to the chronicity of the airway disease and inflammation * Due to the effects of chronic airway inflammation * Can be unresponsive to treatment with inhaled corticosteroids * May be present in asymptomatic or mildly symptomatic (asthma) individuals who show little response to exposure to allergens, exercise or cold air  Viral infections can cause an increase in HRA  Most infants who wheeze have transient conditions associated with diminished airway function and have no increased risk of asthma or allergies later in life.  In a minority early wheezing episodes are related to a predisposition to asthma.  These children already have elevated serum IgE levels during the first six months of life and have substantial deficits in lung function by the age of six years

Answer 3

* Asthma is defined as a chronic inflammatory disorder of the airways, involving mast cells, eosinophils, T lymphocytes (mainly Th2), macrophages, neutrophils and epithelial cells.  It involves a variable degree of 1. reversible airflow obstruction, 2. bronchial hyperresonsiveness, and 3. airway inflammation with mucous hypersecretion and 4. airway remodelling Risk Factors: * Atopy * Either parent ever had asthma * Serious respiratory infection in the first 2 years of life o This includes bronchiolitis, pneumonia, whooping cough, bronchitis or croup * High intake of polyunsaturated fats * Being the first born child * Low birth weight and premature birth * Use of antibiotics in the first year of life Protective factors include (these protective factors tend to promote a Th1 response) * Breast feeding * Having three or more older siblings * Early exposure to animals, either livestock or pets * Exposure to bacterial endotoxins * Living on a farm Risk factors include * Atopy * Either parent ever had asthma * Serious respiratory infection in the first 2 years of life o This includes bronchiolitis, pneumonia, whooping cough, bronchitis or croup * High intake of polyunsaturated fats * Being the first born child * Low birth weight and premature birth * Use of antibiotics in the first year of life

Answer 4

* Clinicalpresentationinvolvesthe symptoms of  Recurrent wheezing,  coughing,  chest tightness/difficulty breathing.  Worse at night or in early morning Examsignsinclude;  rapid breathing,  wheezing,  cough  prolonged expiratory time,  Hyperinflation of the lungs  retractions and nasal flaring  Positive response to bronchodilators  Application of provocative agents such as methacholine and exercise increasing airway resistance and bronchial hyperresponsiveness  Absence of crackles on chest auscultation

Answer 5

Asthma creates the following changes * within the lung tissue: * Smooth muscle hypertrophy and hyperplasia * Inflammatory cell infiltration * Oedema Mucous hypersecretion * Protein deposition, including collagen * Epithelial desquamation * Long term changes in the airways also include: * Increased smooth muscle * Increase in bronchial blood vessels * Thickening of collagen layers * Loss of normal distensibility of the airway Asthma is associated with active T- cell immune responses to inhaled allergens that are skewed toward the Th2 phenotype as compared to the Th1-skewed immunity in healthy individuals Th2 phenotype is the pro-allergy state, and has thought to be brought about by increased hygiene, immunization, decreased sibship size antibiotic use (The Th1/Th2 cytokine balance has been shown to be important. * Asthma is related to a downgraded Th1 response, and an upgraded Th2 response. Inhibition of Th2 cells, mast cells and eosinophils, OR promotion of differentiation of Th0 cells into Th1 cells may be considered protective) Structural changes in asthma 1. Epithelial shedding 2. Collagen deposition 3. Fibrosis 4. Basement membrane thickening 5. Goblet cell hyperplasia 6. Smooth muscle size increase - smooth muscle contraction is determined by inflammation and neurotransmitters.

Answer 6

Just Good Info to know

Answer 7

* Usually is preceded by a viral URTI and is usually viral * Secondary bacterial infection may occur * Clinical Presentation  Typically dry, hacking, unproductive cough with gradual onset 3-4 days  Low substernal discomfort or burning anterior chest pain is often present and may be aggravated by coughing  May develop whistling sounds (rhonchi) and shortness of breath  After several days the cough becomes productive  Within 5-10 days mucous thins and cough clears  May stay quite unwell for a further week (entire episode usually lasts about two weeks) * In healthy children complications are few * There is no specific medical treatment * Antibiotics do not shorten the course of the illness or reduce incidence of bacterial complications Physical Examination: * Early findings are absent or are  low-grade fever and  upper respiratory signs such as  nasopharyngitis,  conjunctivitis, and  rhinitis. * Auscultation of the chest may be unremarkable at this early phase. * As the syndrome progresses and cough worsens, breath sounds become coarse, with coarse and fine crackles and scattered high- pitched wheezing. * Chest radiographs are normal or can have increased bronchial markings. * The principal objective of the clinician is to exclude pneumonia, which is more likely caused by bacterial agents requiring antibiotic therapy.

Answer 8

Infection that inflames air sacs in one or both lungs which may fill with fluid or puss. Can be life threatening to anyone- but particularly infants. Causes: -Mostly micro-organisms/ bacteria -Others can be gastric acid or food inhaled -hypersensitivity reactions A bacterial or viral cause can be identified in 40-80% of children due to new testing procedures VIRAL PNEUMONIA -prominent cause of LRTI in infants and children <5 pro -Viruses = 45% OF HOSPITILISED PNEOMonia in children. -usually occurs between 2-3 yrs -M.c Common is Influenza virus and respiratory Syncytial virus. (major in children)

Answer 9

-Often occur after several days of symptoms of URTI, typically rhinitis and cough. -In viral pneumonia, fever is usually present, temperatures are generally lower than in bacterial -Tachypnea is the most consistent clinical finding (increased work of breathing ie intercostal, subcostal and suprasternal retractions, nasal flaring and use of accessory muscles is common) -Sever infections- may get cyanosis -Auscultation = crackles and wheezing, but often difficult to localise. -Its often not possible to differentiate between viral and bacterial Physical examination: -depends on stage of pneumonia Early on: diminished breath sounds, scattered crackles, and rhonchi are commonly heard over the affected lung field Later on with more consolidation: dullness on percussion notes and diminished breath sounds. A lag in respiratory excursion often occurs on the affected side. Abdominal distention may be prominent because of gastric dilation from swallowed air or ileus. Abdominal pain is common in lower lobe pneumonia -liver seems to be enlarged because of downward displacement of the diaphragm

Answer 10

Infants may get abrupt onset of: -fever -restlessness -apprehension -respiratory distress Some infants with bacterial pneumonia may have associated GI disturbances, vomiting, anorexia, diarrhoea, abdominal distention. Rapid progression of symptoms in most sever cases of bacteria pneumonia. These infants appear ill, with respiratory distress manifested as: -Grunting -Nasal flaring-Retractions of the supra-clavicular, intercostal and subcostal areas -Tachypnea (fast breathing rate) >60 -Tachycardia (fast heart rate) -Air hunger -Often cyanosis Diagnosis of Pneumonia: -Chest Xray may show - infiltrate/ pleural effusion -Lobar consolidation -The Xray alone is not diagnostic, other clinical features must be considered

Answer 11

-Fever -Decreased Breath sounds -Crackles -Tachypnea

Answer 12

6 month old infant * A, Radiographic findings characteristic of respiratory syncytial virus pneumonia in a 6 mo old infant with rapid respirations and fever. * Anteroposterior radiograph of the chest shows hyperexpansion of the lungs with bilateral fine air space disease and streaks of density, indicating the presence of both pneumonia and atelectasis. An endotracheal tube is in place. * B, One day later, the AP radiograph of the chest shows increased bilateral pneumonia.

Answer 13

* Radiographic findings characteristic of pneumococcal pneumonia in a 14 yr old boy with cough and fever. Posteroanterior (A) and lateral (B) chest radiographs reveal consolidation in the right lower lobe, strongly suggesting bacterial pneumonia.

Answer 14

* The definitive diagnosis of a viral infection rests on the isolation of a virus or detection of the viral genome or antigen in respiratory tract secretions. * Growth of respiratory viruses in conventional viral culture usually requires 5-10 days, although shell vial cultures can reduce this “turnaround time” to 2-3 days. * Reliable DNA or RNA tests for the rapid detection of RSV, parainfluenza, influenza, and adenoviruses are available and accurate.

Answer 15

* The definitive diagnosis of a bacterial infection requires isolation of an organism from the blood, pleural fluid, or lung. * Culture of sputum is of little value in the diagnosis of pneumonia in young children. * Blood culture results are positive in only 10% of children with pneumococcal pneumonia. * Acute infection caused by M. pneumoniae can be diagnosed on the basis of a positive polymerase chain reaction (PCR) test result or seroconversion in an IgG assay. * Serologic evidence, such as the antistreptolysin O (ASO) titer, may be useful in the diagnosis of group A streptococcal pneumonia.

Answer 16

* If viral pneumonia is suspected, it is reasonable to withhold antibiotic therapy, especially for those patients who are mildly ill, have clinical evidence suggesting viral infection, and are in no respiratory distress. * Up to 30% of patients with known viral infection may have coexisting bacterial pathogens. * Therefore, if the decision is made to withhold antibiotic therapy on the basis of presumptive diagnosis of a viral infection, deterioration in clinical status should signal the possibility of superimposed bacterial infection, and antibiotic therapy should be initiated. PROGNOSIS: -Bacterial: symptoms (fever, cough, tachypnea, chest pain) improve within 48-96 hours after antibiotics. But Chest Xray evidence takes substantially longer/

Answer 17

Pneumonia Bilateral central pulmonary infiltrates, but most marked in the right middle and left lower lobes. The left lower lobe infiltrate is best seen on the lateral view inferiorly over the spine. The lungs are hyperaerated. Impression: Right Middle and left lower lob infiltrates

Answer 18

* The left lung is consolidated. This atelectasis results in a mediastinal shift to the left. There are air bronchograms evident over the left lung. On the original film, there is a suggestion of a 1.5cm cylindrical foreign body in the left mainstem bronchus. Further history revealed that he had "swallowed" a plastic bullet several days ago. * Impression: Consolidation of the entire left lung with the suggestion of a foreign body in the left mainstem bronchus

Answer 19

* There are small interstitial central pulmonary infiltrates. * Impression: Small interstitial central pulmonary infiltrates most consistent with a viral pneumonia.

Answer 20

* The upper mediastinum shows the usual prominent thymus for this age. The thymic shadow is larger on the infant's right than on his left. There is a density in the right upper lobe, but it is obscured by the thymus. Part of this density appears to be from the scapula, but on close inspection, there are densities suggesting infiltrates aside from the thymus and the scapula in the right upper lobe. * Impression: Right upper lobe infiltrate or partial atelectasis. Atelectasis (at-uh-LEK-tuh-sis) is a complete or partial collapse of the entire lung or area (lobe) of the lung. It occurs when the tiny air sacs (alveoli) within the lung become deflated or possibly filled with alveolar fluid. Atelectasis is one of the most common breathing (respiratory) complications after surgery.

Answer 21

* There is a small area of atelectasis in the right middle lobe. This is best seen on the lateral view as an oblique flattened wedge shaped density over the heart. Instead of the normal triangular shape of the right middle lobe, it appears to be flat and compressed indicating atelectasis. * Impression: Right middle lobe atelectasis. Atelectasis (at-uh-LEK-tuh-sis) is a complete or partial collapse of the entire lung or area (lobe) of the lung. It occurs when the tiny air sacs (alveoli) within the lung become deflated or possibly filled with alveolar fluid. Atelectasis is one of the most common breathing (respiratory) complications after surgery.

Answer 22

A 12-year old female complaining of a headache and productive cough. Onset of fever last night to 39 degrees. Rales are noted in the left base. * There are infiltrates in the right middle and left lower lobes. The right middle lobe infiltrate is blurring the right heart border. It can also be seen on the lateral view as streakiness over the heart. The left lower lobe infiltrate is best seen on the lateral view posteriorly on the diaphragm. It can also be seen on the PA view as haziness in the lower lung on the left. The infiltrate in the right middle lobe was noted two years ago on a previous radiograph, and the possibility of a chronic infiltrate was raised. * Impression: Right middle and left lower lobe infiltrates. The term pulmonary infiltrate is considered a context-dependent, non-specific and imprecise descriptive term when used in radiology reports (plain film or CT). From a pathophysiological perspective, the term "infiltrate" refers to “an abnormal substance that accumulates gradually within cells or body tissues” or “any substance or type of cell that occurs within or spreads as through the interstices (interstitium and/or alveoli) of the lung, that is foreign to the lung, or that accumulates in greater than normal quantity within it”

Answer 23

This is a 9-year old male with a history of fever, headache, nausea, and coughing. * There is a circular density in the right lung. This is the superior segment of the right lower lobe. Although this has the appearance of a mass, it is most likely an infectious process. * Impression: Spherical consolidation in the right lower lobe (round pneumonia).

Answer 24

Diagnosis: -should be suspected in kids who has a pure predominant complaint of cough, especially if the following features are absent: fever, malaise or myalgia, sore throat, tachypnea, wheezes and rales. A cough >14 days duration with at least 1 associated symptom of -paroxsms, -whoops -post- tussle vomiting has sensitivity of 81% -Pertussis should be suspected in older children whose cough illness is escalating at 7-10 days and whose coughing episodes are not continuous -Pertussis should be suspected in infants <3mo of age with gagging, gasping, apnea, cyanosis, or an apparent life threatening event. -Sudden infant death is occasionally caused by B pertussis. TREATMENT: -maximise nutrition, rest and recovery without sequelae -Infants <3 months suspected. always admitted to hospital -No medications provide symptomatic relief from pertussis - associated cough -Antibiotics eliminate B pertussis from the nasopharynx and reduce the risk of transmission -AB have not been shown to reduce duration or severity of cough. FINITO

Module 12 The Respiratory System Flashcards

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