NURS8026Exam # 1 Study Guide Lectures: 1 - 3Lecture 1 (January 13) DIAGNOSTIC REASONING Definition: – Dynamic thinking process that leads to the identification of a hypothesis that best explains the clinical evidence. – A method of exploring a patent problem using an approach that is systematic and organized, resulting into the genera6on of a hypothesis. Purpose of diagnostic reasoning: – Identify potential underlying causes of the manifested problem – Narrow the hypothesis: eliminate the false – Develop appropriate treatment or management plan – Resolve /manage the problemFactors that affect reasoning: – Patent driven • increasing acuity • Poor historians • altered mental status • Multisystem disease: acute & chronic • Multiple complaints– Clinician driven – • Limited experience • Knowledge base • Continuous review of data • Uncertainty of data • Demands for cost effectiveness and speedInfluences on diagnostic reasoning: – Study by Brykczynski (1989) describing clinical judgment of NPs – Maxims are guiding principles used by experts • Common things occur commonly • Real disease declares itself • Follow-up is everything • AphorismsHypotheses Driven Strategy • Used to rule out conditions or diseases• Done progressively on the basis of medical history, physical examination, diagnostic tests • Modification & refinement occur until “working hypothesis” is generated Identifying the problem: – ID the important S/S – done through focused listening – Experience in recognizing subtle clues – Can be jeopardized by inhibiting free expression of patent – Bias of clinician that focuses on a single sign – Multiple complaints require priority assignment according to risk • Life threatening, greatest severityDifferential Diagnosis: process that involves logical analysis of all possible causes of patent complaint – Initial list exhaustive – deciding which belong depends on what condi6ons come easily to mind – Errors occur from omission stemming from haphazard method to make list• Differen6al Diagnosis: process – Prioritize the list: • Possibility • Probabilistic: consider most likely w/highest pretest probability • Prognostic: most serious first • Pragmatic: most responsive to treatmentSelection of Diagnostic Tests • Tests possess certain characteristics • These characteristics answer 2 fundamental questions • What proportion of those patients who have the disease will have an abnormal (positive) result? =Sensitivity • What proportion of those patents who do not have the disease will have a normal (negative) result Specificity• Sensitivity – The proportion of the patents who have the specific disease and are so identified by the test – All patents with the disease have a positive test no one w/the disease has a negative test – 100% – A high sensitivity has few false negatives – Will confirm the presence of disease – Used to exclude a diagnosis or rule out a disease – True positive rate – Negative result means a low likelihood that the patent has the diseaseSpecificity – Proportion of people who are free of a specific disease and are so iden6fied by the test – No healthy patents (no one w/out the disease has a +) have a posi6ve test = 100% – True negative rate – Few false positives– Will confirm the absence of disease – Used to confirm a diagnosis or to rule in a disease – If the patent has a positive result they likely have the diseaseLecture 2 (January 20) Lecture: Differential diagnosis of Shortness of Breath (SOB)1. Important questions to ask if anybody comes with SOB2. Have you had any sick contact?3. When does it start?4. What makes it better/worst? 5. Are you contact anybody who are sick6. Any recent respiratory infection?7. Any recent weight change?8. Do you smoke?9. Any recent trauma?10. How the problem effects on ADL?11. Any PND-? (Attacks of breathlessness occurring at night12. What is the quality of breathing? 13. Are you coughing with sputum (frothy sputum-sigh of infection)Definiton:1. SOB, breathlessness and dyspnea all refer all refer to an abnormal awareness of breathing2. Sensation of difficult, uncomfortable breathing includes both perception of labored breathing and the patient’s reaction to that sensation.3. Common presenting complain can be insidious or abrupt-acute or chronic 4. Orthopnea refers to dyspnea in recumbency 5. PND are attacks of breathlessness occurring at night awakening the patient Pathophysiology of SOB:– Many “dyspnea ’mechanisms not entirely clear– Increased stimulate on of brain-stem respcenter; area of Medulla contains coordina3ngcenters• Pneumotaxic center: controls rate & paMern• Dorsal resp group: controls inspiration• Ventral group: controls modulates inspiration& expirationDifferental Diagnosis of SOB• Usually a system related problem• Can stem from pulmonary, cardiac, anemia, hypothyroidism, N/M diseases• Difficult to differentiate cardiac from pulmonary may be a cardiopulmonary diseaseCategories of possible dysfunction (SOB): -Pulmonary system• Airway• Parenchyma• Pleura• Chest wall• Blood vessels– Cardiac dysfunction– Neuromuscular– Anxiety disorderDyspnea (also SOB, air hunger)Subjective symptom of breathlessness.Normal in heavy exertionPathological if it occurs in unexpected situations.Differential diagnosis of Shortness of BreadthStress/anxiety/deconditioningHeart DiseaseEmboli Pulmonary diseaseAnemiaNeuromuscular diseaseTrachea/upper airway obstructionSleep disorderAcute Condition SOB1. Aspiration of Foreign Body2. Anaphylaxis3. Pulmonary embolism (PE)4. Spontaneous Pneumothorax5. Status asthmatic6. Acute bronchial asthma7. Pneumonia8. Noncardiogenic pulmonary edema- ARDS- Noxious gas inhalation- High altitude pulmonary edema, 8. Cardiogenic pulmonary edema 9. HyperventilationChronic conditions– COPD: Emphysema, Chronic bronchitis, Chronic bronchial asthma– Restrictve lung disease:- Intestinal (e.g. Sarcoidosis, scleroderma)- Chest wall deformities- Pleural fibrosis- Neuromuscular disease(ALS,myasthenia gravis)– Nonpulmonary causes:• CHF (low output states)• Anemia• Hyperthyroidism• Upper airway disease• Obesity• NeurosisChronic Condition Of SOBAnemiaAnemia:1. 65% of the FE(Iron is in circulating HgB.2. 1 ml of blood=0.5mg FE9Iron)3. Each healthy pregnancy depletes body 500mg of Fe4. Male must