Intro to Differential Diagnosis Flashcards
*Describe the diagnosis processes
1) Pattern recognition
2) Hypothetico deductive
- Hypothesis generation
3) Algorithm
4) Exhaustive
5) Logical reasoning
*Components of illness scripts
- Pathophysiology: what causes the disease
- Epidemiology: who commonly gets this disease
- Time course: how long it’s been going on
- Symptoms & signs
- Diagnosis: results of testing
- Treatment: how would you treat this disease
*Differences between diagnosis informed care and medical screening
Diagnosis: uses directed questions & focused physical examination tests in a hypothesis-driven manner
Medical Screening: general systems review with the goal to assess for risk factors that may impact patients’ overall well-being
*Classification system of red flag screening
I = suggests serious pathology outside of MSK disorder, possible immediate intervention by a specialist
II =further patient questioning & adoption of selected examination methods
III = common, require further physical examination, likely to alter treatment
*Procedures to improve diagnostic accuracy (possible causes)
- TIM VaDeTuCoNe
- Trauma
- Inflammation: aseptic or septic
- Metabolic condition
- Vascular: arterial, venous, or lymphatic
- Degenerative
- Tumor: malignant primary, malignant metastatic, or benign
- Congenital
- Neurogenic/Psychogenic
Examples of a medical diagnosis
- stroke
- fracture
- foot pain
Examples of a PT diagnosis
- impaired gait
- generalized weakness
- decreased force production
- impaired AROM
- pain
- decreased strength
What is a diagnosis
- Process + product of a clinical investigation related to the pathology underlying a patient/client’s signs & symptoms resulting in a label
- investigation + label = diagnosis
What are some goals of a diagnosis
- (Primary) determine whether PT services are indicated for the patient’s condition
- identify the target disorder
Diagnosis limitations
- cause of condition may not be determined
- label may not be descriptive
- specificity of labeling depends on information & experience
4 possible options for is the suspected diagnosis within scope of practice
- Emergency referral: as a guide, on the same day
- Urgent referral: as a guide, within 5 days
- Watchful waiting: close surveillance while undergoing tx as required while allowing time to pass before medical intervention “treat and refer”, safety netting
- Appropriate referral: diagnosis is within scope of practice, evaluate and treat
Define safety netting
- management strategy used for people who may present with possible serious pathology
- strategies should include advice on which signs & symptoms to look out for, which action to take, & the time frame within which that action needs to be taken
*Describe performing diagnosis informed care
- PT interprets the diagnosis to determine appropriate intervention & prognosis
- MUST prioritize the most important aspects of disablement to address in pain
- most interventions have an indirect effect on pathology
- requires PT to determine cause/effect between pathology & functioning
Limitations of diagnosis informed care
- the label alone is insufficient to guide PTs
- most PT referrals indicate: shoulder, knee, hip, back pain
- essentialist approach relates to mechanism
- “treat the patient, not the diagnosis!”
Define essentialism
- treatment of the cause/source is more effective than treating individual signs & symptoms
- mechanism is not always directly responsible for impairment in functioning
Where to start in thinking about a diagnosis
- Formal processes decrease error
- Start with the question: What disease is causing my patient/client’s dysfunction?
Define backward and forward reasoning
- Backward: make hypothesis and test it (novice)
- Forward: pattern recognition (expert)
Common age pattern for biceps tendonitis
- common in 18-35 y/o involved in sports
Pattern recognition foundations
- Frequency: how common is the condition in that age group
- Variability: inferences about entire population based on small subset patients
- Causation: whether the person has a disease or not
- Prototype: comparing a disease found in one patient to another with similar characteristics
- Location: remote (referred) or local (palpation/over anatomy)
Types of follow up questions to help differentiate/eliminate as many diseases as possible
- Key feature: specific to a disorder & not others
- Rejecting feature: if present then it is not the disorder & probably something else
- Non-differentiating feature: common to several disorders (narrowing of possibilities)
- Differentiating feature: specific to one or two disorders (further narrowing of possibilities)
Difference between medical screening and red flag screening
Medical: involves an algorithmic process of systems based health review and focuses on the search for “Red Flags”
Red Flags: lack diagnostic accuracy to predict intended conditions and interpretation is often context-dependent requiring a deeper level of processing
Red flags cluster for malignancy
- > 50 y/o
- failure of conservative management
- unexplained weight loss
- history of cancer
- sensitivity of 100% for identifying a malignancy
Examples of immediate medical attention (I) red flags
- blood in sputum (coughed up substance)
- loss of consciousness/altered mental status
- neurological deficit not explained by monoradiculopathy
- bowel/bladder changes
- patterns of symptoms not compatible with mechanical pain
- pulsatile abdominal masses
Examples of require further physical tests & differential analysis (II) red flags
- abnormal reflexes
- bilateral or unilateral radiculopathy/paresthesia
- unexplained referred pain
- unexplained significant upper/lower limb weakness
Examples of subjective questioning/examination procedures (III) red flags
- > 50 y/o, clonus, fever, elevated ESR, gait deficit
- Hx of disorder with infection/hemorrhage
- Hx of metabolic bone disorder
- Hx of cancer
- impairment precipitated by recent trauma
- long term corticosteroid use
- long term workers compensation
- non-healing wounds/sores
- recent unexplained weight loss
- writhing pain
Diagnostic process for differential diagnosis/imaging
- Identify patient’s chief concern & determine any communication barriers
- Identify any red flags through medical screening
- Create a sign/symptom timeline & appreciate anatomy
- Create diagnostic hypotheses considering all possible forms of remote & local pathology
- Ask specific questions to rule specific conditions as less likely
- Perform tests to differentiate among remaining diagnostic hypotheses
- Decide on a diagnostic impression
- Determine appropriate plan of care (referral types)
Risk factors for cardiovascular issues
- (+)Age: men ≥45, women ≥55
- (+)Family Hx: MI, coronary revascularization, or sudden death <55 in father or <65 in mother
- (+)Cigarette Smoking: current smoker or quit within previous 6 mo
- (+)Sedentary Lifestyle: <30 min of moderate intensity exercise at least 3 days per week for at least 3 mo
- (+)Obesity: BMI ≥30 or waist >102 cm/40 in for men, waist >88 cm/35 in for women
- (+)Dyslipidemia: LDL ≥130 or HDL <40, total >200
- (+)Pre-diabetes: fasting glucose ≥100 but <126, 2 hr oral test ≥140 but <200
- (-)High HDL Cholesterol: ≥60
