Problem Based Learning & Applied Clinical Skills

=Pneumonia & Lung Pathophysiology=

pneumonia
Pneumonia can range from mild to severe, and can even be deadly. The severity depends on the type of organism causing pneumonia, as well as your age and underlying health.
 * Pneumonia is an infection of the lungs. Many different organisms can cause it, including bacteria, viruses, and fungi.
 * Diminished breath sounds, tachypnea, crackles.

pleural effusion

 * Excessive non-purulent fluid in the pleural space
 * Analysis of pleural fluid allows for identification of the pathophysiologic process leading to accumulation of pleural fluid (i.e.: is it transudative, exudative?)
 * Transudative causes: fibrosis, heart failure, cirrhosis
 * Exudative causes: bacterial pneumonia, malignancy, viral infection, and pulmonary embolism (source: Harrisons)

empyema

 * An empyema is a collection of pus within a naturally existing anatomical cavity. It must be differentiated from an abscess, which is a collection of pus in a newly formed cavity within the lung parenchyma.
 * Breath sounds distant or absent, percussion is dull, vocal fremitus absent
 * Patient appears very ill, febrile, techypneic.
 * Because of the significant morbidity and mortality associated with empyema, the primary focus of managing parapneumonic effusions centers on early detection and urgent evaluation to identify those patients who require pleural fluid drainage to prevent or treat an empyema.
 * Associated with pneumococcus, S. Aureus, Kleibsiella

Describe the pathophysiology of pneumonia.
- an inflammatory illness of the lung frequently involving parenchymal and alveolar inflammation and abnormal alveolar filling with fluid. It can result from a variety of causes including infection with bacteria, viruses, fungi, parasites and chemical or physical injury to the lungs. Typical symptoms include cough (productive and non-productive), chest pain, fever, and difficulty breathing. Diagnostic tools include physical exam, chest X-rays/CTs and sputum culture. Treatment depends on causative agent.

Describe the characteristics of a pericardial rub.
Systolic and diastolic components, scraping quality, high pitch

Describe the findings of lung consolidation.
Fluid in lung. May indicate pneumonia. Lung exam shows expansion of the thorax on inspiration is reduced on the affected side, increased tactile fremitus  (patient says “boy,” note vibration) on side of consolidation, affected area is dull to percussion, crackles often in LL lobe, pleural rub, bronchial breath sounds.

Describe the characteristics of a pleural rub.
The sounds may be discrete, but sometimes are so numerous that they merge into a seemingly continuous sound. A rub is usually confined to a relatively small area of the chest wall, and typically is heard in both phases of respiration.

Describe the findings of pleural effusion.
Excess fluid in pleural cavity. Lung exam findings include decreased movement of the chest on the affected side, dullness to percussion over the fluid, diminished breath sounds on the affected side, decreased tactile fremitus(patient says “boy,” diminished vibration), pleural friction rub, and egophony (patient says “E,” you hear “A”)

Describe the inheritance pattern of polycystic kidney disease.
Autosomal dominant polycystic kidney disease (ADPKD) is seen predominantly in adults, whereas autosomal recessive polycystic kidney disease (ARPKD) is mainly a disease of childhood.
 * ADPKD occurs in 1:400–1:1,000 individuals worldwide and accounts for ~4% of end-stage renal disease (ESRD) in the United States. Over 90% of cases are inherited as an autosomal dominant trait, with the remainder likely representing spontaneous mutations.

=Heart Sounds & Pathophysiology= This site will never reach the sophistication of two great resources: Blaufuss.org and the Auscultation assistant. We recommend that you visit these sites for the answers to the following objectives.

Intensity
Grade 1 refers to a murmur so faint that it can be heard only with special effort. A grade 2 murmur is faint, but is immediately audible. Grade 3 refers to a murmur that is moderately loud, and grade 4 to a murmur that is very loud. A grade 5 murmur is extremely loud and is audible with one edge of the stethoscope touching the chest wall. A grade 6 murmur is so loud that it is audible with the stethoscope just removed from contact with the chest wall.

Pitch
Frequency or pitch relates to the velocity of blood at the site of origin of the murmur and is designated as high, medium, or low. In general, the higher the velocity, the higher the pitch of the murmur.

Quality/Shape
Quality refers to the tonal effect of the murmurs. Frequently used descriptors are blowing, musical, squeaking, whooping, honking, harsh, rasping, grunting, and rumbling. Some people consider Shape to be different than the quality. Shape refers to crescendo, decrescendo, etc.

Duration/Timing
Duration/Timing refers to the portion of the cardiac cycle that the murmur occupies. Murmurs may be systolic, diastolic, or continuous. For example, systolic murmurs may be early systolic, midsystolic, late systolic, or holosystolic.

Location
The primary location or point of maximum intensity

Radiation
Radiation to the carotids, is characteristic of aortic stenosis.

Aortic stenosis
The murmur of aortic stenosis is typically a mid-systolic ejection murmur, heard best over the “aortic area” or right second intercostal space, with radiation into the right neck. This radiation is such a sensitive finding that its absence should cause the physician to question the diagnosis of aortic stenosis. It has a harsh quality and may be associated with a palpably slow rise of the carotid upstroke. Additional heart sounds, such as an S4, may be heard secondary to hypertrophy of the left ventricle which is caused by the greatly increased work required to pump blood through the stenotic valve. Because the second heart sound is largely generated by the sudden closing of the aortic valve, a poorly mobile and stenotic aortic valve may cause S2 to become quieter or even absent. Although S2 is normally created by the closure of the aortic valve followed by the pulmonary valve, if the closure of the aortic valve is delayed enough, it may close after the pulmonary, creating an abnormal paradoxical splitting of S2.
 * Hear an examples of early aortic stenosis and late aortic stenosis

Mitral Regurgitation

 * Mitral valve regurgitation is usually either a congenital condition or a consequence of rheumatic heart disease, marked left ventricular dilatation, acute infective endocarditis, or papillary muscle dysfunction secondary to acute or prior myocardial infarction.
 * This murmur is usually best heard at the apex, with radiation into the axilla. Because the mitral valve is unable to contain the blood within the ventricle for the entire systolic period, it is a holosystolic murmur.
 * The quality of the murmur is usually described as blowing, and it is often associated with an S3 because of the left atrial volume overload.
 * Although S1 is due to a combination of mitral and tricuspid valve closure, the mitral valve is the louder aspect. Because the valve closure in mitral regurgitation is incomplete, S1 may be noticeably quieter.

Additional information about Systolic Murmurs

Describe the characteristics of Aortic Regurgitation (insufficiency).

 * Diastolic murmur - Note that S2 is shown before S1 above!!!
 * high pitch
 * The murmur of aortic regurgitation is complex. The left ventricle is typically dilated secondary to extreme volume overload, as it must handle both the forward flow delivered from the left atria as well as the regurgitant flow from the aorta. This large volume of blood is ejected rapidly during systole, and an early mid-systolic flow murmur is frequently audible over the right upper sternal border with radiation into the neck.
 * Hear an Aortic Insufficiency and here, too

Differentiate between S3 and S4.


= References =