~tpapastylianou/systematic-approach-to-medicine

This document details a systematic approach to medicine, which I compiled back when I was a medical student, and continued updating as a junior doctor. It is one possible example to the question "Do you have a system?" which everyone seemed to always ask, but nobody ever seemed to offer a satisfying answer to.

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~tpapastylianou/systematic-approach-to-medicine

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#A Systematic Approach to Medicine

  • Condition synopsis
  • Epidemiology
  • Associations
  • Aetiology
  • Pathophysiology
  • History
  • Physical Examination
  • Differential Diagnoses
  • Investigations
  • Management
  • Complications
  • Medicolegal
  • Prognosis

Condition synopsis

  • Name
  • Eponym
  • Etymology + Definition
  • Description
  • Optional: Historical background
  • (Formal) Criteria and Classifications

Epidemiology

  • Frequency
    • Incidence
    • Prevalence
    • Commonness (e.g. in terms of GP consultations or hospital admissions)
    • Mortality
  • Age of Presentation
  • Gender differences
  • Geographical Variation
  • Other specific environmental factors
  • Low- vs High-risk groups

Associations

(i.e. what are the two important questions that need to be asked / aspects of the current diagnosis and treatment, with respect to how they relate to other conditions in an epidemiological sense?) "Assuming X is the condition under investigation, and Y is the associated condition to be addressed:

  • "What is the % risk that people with X have (prevalence), or are generally expected to develop (incidence) Y?" -- Treatment / Prevention

  • "What is the % risk that people with Y would already have (prevalence), or would have generally been expected to develop (incidence) X?" -- Differential diagnosis


Aetiology

  • Serious causes (usually rare and to be excluded)
  • Common causes
  • Surgical Sieve! (mnemonic: INVESTIGATIONS):
    • I atrogenic (!)
      Always exclude this first: it tends to be the most common cause of modern disease, yet typically also the most overlooked!
      (include self-treatments in this category too)

    • N eoplastic

    • V ascular

    • E ndocrine / Metabolic

    • S tructural / Mechanical

    • T raumatic / Environmental

    • I nflammatory / Infective

    • G enetic / Congenital

    • A utoimmune

    • T oxic / Self-toxic

    • I maginary / Psychiatric

    • O ld age / Degenerative

    • N utritional / Neurological

    • S pontaneous / Idiopathic


Pathophysiology

  • Normal Physiology / Anatomy / Biochemistry
  • Embryology / Development (if relevant)
  • Microscopic features
  • Macroscopic features
  • (Spread)

History (Hx)

  • Preliminaries / Background information
  • Presenting Complaint (PC)
  • History of Presenting Complaint (HPC)
  • Review of Systems (ROS)
  • Past Medical History (PMHx)
  • Drug History (DHx)
  • Family History (FHx)
  • Social History (SHx)
  • Summary

History : Preliminaries

  • Date, Time and Place
  • Person taking / signing history
  • Reason for history (i.e. 'admission clerking', 'asked to see patient', 'ward round' etc)
  • Name, Date of Birth (Age), Gender, Patient Details, GP's name
  • Patient's non-medical background ("Tell me a bit about yourself. [...?] Well, introduce yourself to me: What do you do, where are you from, anything in particular you'd like me to know about you as a person?")
    This might come off as a bit weird if not executed properly; however, when done correctly, it establishes rapport, helps both you and the patient to see the patient as more than the disease, it helps put this event in the context of the human being it relates to, and can typically give useful information or context that would not have otherwise come up during the History, e.g. their dog is at home and the reason they're keen to self-discharge is because of the dog; a loved one recently passed away leaving them in financial trouble; they live in an isolated place making their emergency even scarier; they are a celebrity who is worried about press; their living circumstances are dire but they don't like to make a fuss; etc.

History : Presenting Complaint (PC)

  • What
  • When
  • Where? / Which side?
  • How / Why

History : History of Presenting Complaint (HPC)

  • SOCRATES:
    • Site
    • Onset
    • Character
    • Radiation
    • Associated Symptoms
    • Temporal Pattern
    • Exacerbating or alleviating factors
    • Severity (1 to 10)
  • Specific questions associated with specific presentation
  • Relevant System History (c.f. ROS)
  • Relevant History
    • Has it happened before?
    • Is there a relevant background to this
    • Any relevant recent developments / interventions
  • Aetiology directed questions
    • To confirm / strengthen suspected diagnosis
    • To exclude differential diagnoses
    • To establish Risk factors

History : Review of Systems (ROS)

  • General
  • Cardiovascular
  • Respiratory
  • Gastrointestinal
  • Urinary
  • Obstetric / Gynaecological
  • Neurological
  • Metabolic / Endocrine
  • Musculoskeletal
  • Dermatological
  • Haematological

Hx: ROS: General

  • Weight and appetite
  • Energy levels
  • Sleep
  • Mood
  • Fever

Hx: ROS: Cardiovascular

  • Chest pain
  • Breathlessness on exertion
  • Exercise tolerance
  • Palpitations
  • Syncope
  • Claudication
  • Ankle swelling
  • Orthopnoea / Paroxysmal Nocturnal Dyspnoea

Hx: ROS: Respiratory

  • Breathlessness
  • Chest pain associated with respiration
  • Cough
  • Sputum
  • Wheeze
  • Haemoptysis
  • Hoarseness

Hx: ROS: Gastrointestinal

  • Mouth ulcers
  • Dysphagia
  • Nausea or Vomiting
  • Haematemesis
  • Indigestion / Heartburn
  • Abdominal pain / discomfort
  • Adbominal masses
  • Weight loss / appetite
  • Change in bowel habit (constipation / diarrhoea)
  • PR Blood loss

Hx: ROS: Urinary

  • Dysuria
  • Polyuria
  • Nocturia
  • Frequency
  • Haematuria
  • Discharge
  • Incontinence (stress / urge)
  • Prostatism (frequency, urgency, hesitancy, incomplete emptying, straining, poor stream dribbling)
  • Loin / renal angle pain

Hx: ROS: Obstetric / Gynaecological

  • Loin pain (often cyclical)
  • Menstruation problems (heavy / painful / inexistent / irregular )
  • Pregnancies / Chance of Pregnancy
  • PV Discharge / Bleed
  • Dyspareunia

Hx: ROS: Neurological

  • Headache
  • Dizziness / N&V
  • Weakness
  • Sensory loss / disturbance
  • Fits / Faints
  • Visual disturbance
  • Other special senses disturbance (e.g. hearing)
  • Loss of higher mental function (Confusion / Memory)
  • Speech (subjective vs objective)

Hx: ROS: Metabolic / Endocrine

  • Symptomes of hypo / hyperthyroidism
  • Symptoms of diabetes
  • Symptoms of metabolic disturbances (cramps, tetany etc)
  • Symproms of endocrine disturbances (sexual dysfunction, steroids, growth)

Hx: ROS: Musculoskeletal

  • Muscle or joint pain
  • Stiffness
  • Joint swelling
  • Disability / deformity
  • Weakness / limitation of movement
  • Falls / Trauma

Hx: ROS: Dermatological

  • Rashes
  • Inflammation
  • Skin allergies
  • Swelling
  • Lumps / bumps
  • Pruritus
  • Open wounds / ulcers / infections

Hx: ROS: Haematological

  • Anaemia (pale, tired) - low red cell count
  • Recurrent infections - low white cell count
  • Bleeding & Bruising - low platelet count

Past Medical History (PMH)

  • Previous Surgery + Anaesthetics Hx
  • Other Medical Admissions
  • Other Chronic diseases (e.g. monitored by GP)
  • Screening Questions
  • Treatment background

PMH: Screening Questions (per system)

  • General: Cancer / Congenital-Genetic / Problems of Psych. nature
  • Cardiovascular: Angina / MI / AF / CCF / HTN / Valves
  • Respiratory: Asthma / COPD / Clots
  • Gastrointestinal: Bleeds / Jaundice
  • Renal: Renal Failure
  • Obs/Gynae: Complications in pregnancy / Menstrual problems
  • Neuro: Epilepsy / Stroke / Dementia
  • Endocrine: Diabetes / Thyroid
  • Musculoskeletal: Arthritis / Falls / Significant Trauma
  • Dermatological: Anaphylaxis
  • Haematological: Transfusions / serious infections (TB / Rh.Fev / HepC)

PMH: Treatment background
"I.e. any past or future investigations or procedures or home treatment relevant to admission or background condition?"
For instance:

  • IHD: Previous stents? Angiogram? Echo?
  • Clots/AF/Valves: Warfarin? Duration/Dose?
  • Asthma/COPD: Previous ITU? PEFR? Home nebs/O2?
  • Bleeds: Endoscopy? Banding? PPI?
  • RF: Dialysis? Type? Frequency?
  • Diabetes: Type? Insulin? Previous Hypo/DKA?
  • Cancer: XRT / Chemo?

Drug History

  • Drug Allergies (or Resistances)
  • Drugs on admission
  • Drugs started / to be started during current admission
  • Recent changes in medication
  • Note drugs suspiciously absent given current conditions and PMHx
  • Non-obvious drugs (like contraceptives, St Johns Wort, herbal etc)
  • Know individual DRUG PROFILES and identify potential interactions

Drug Profile

  • Name (generic + commond brands)
  • Class of drug + pharmacological action
  • Indications
  • Administration
    • Dose
    • Route
    • Frequency and duration (e.g. in antibiotics)
    • Special instructions to patient or staff
  • Contraindications / Cautions
  • Interactions
  • Side effects / complications

Family History

  • Mental (or written) impression of Family tree.
    • Parents alive?
    • Any brothers or sisters? Close?
    • Wife? Children? Healthy?
  • Any FHx relevant to patient's Presenting Complaint?
  • Any serious / genetic conditions in the family?

Social History

  • Home situation (family proximity, family health, carers, support, housing)
  • Handicap: How are they affected at home, hobbies and social life.
  • Assessment of function: ["DEATH SHAFT" mnemonic]
  • Travel History (if relevant)
  • Smoking / Alcohol / IVDU / sexual Hx (where relevant)

Assessment of function: "DEATH SHAFT" mnemonic

  • Basic functions
    • Dressing self (including buttons)
    • Eating
    • Ambulating (including stairs)
    • Toileting
    • Hygiene (e.g. showering)
  • Advanced functions
    • Shopping
    • Housekeeping
    • Accounting
    • Food preparation
    • Transportation

Hx: Summary

  • Summary - clarification - wrapping things up
    E.g. "Right, I will now summarize what we've just talked about back to you, to confirm that I got everything correctly, ok? So, you felt some pain around 8pm; this was a dull ache in the centre of the chest [...]" , etc.
    This achieves two things:
    a) it enables you to reconstruct a fluff-free to-the-point summary of events, which the patient can confirm/endorse, or correct if you misunderstood something.
    b) During History taking, one generally wants to ask open-ended questions as much as possible (to avoid 'leading' the patient), and to let the patient talk, and listen without interrupting too much. Summarising it all back to the patient like this enables the patient to see what your agenda was during that discussion, and what you were actually paying attention to, which may be different to what the patient thought you were after. This in turn may prompt more relevant details and clarifications.

  • After summary: "Is there anything I missed, or anything else you could think that is relevant"

  • "Any questions / comments / concerns that have not been addressed (before I start the examination)?"


Physical Examination / Clinical signs

  • EXAMS : Be seen to do what they expect you to do in the order they expect to see you do it
  • REAL LIFE : Whatever helps you be systematic and not miss important stuff

Investigations - (Types / Groups)

  • Laboratory analysis of specimens
    • Types of specimens
    • Types of analysis
  • Assessments of function and performance
  • Image acquisition techniques
  • Direct visualization procedures
  • Invasive procedures
  • Specific diagnostic tests and procedures

Lab analysis: Types of specimens

  • Venous Blood
  • Arterial Blood
  • Capillary Blood (i.e. glucose)
  • Urine
  • Sputum
  • CSF
  • Pus
  • Aspirate
  • Tissue

Lab analysis: Types of Analysis

  • Haematological
  • Biochemical
  • Microbiological
  • Immunological
  • Endocrinological
  • Generic Screens and profiles, vs Specific Tests.
  • Observation (macro vs microscopic)
  • Genetic tests

Haematological tests

  • Full blood count (FBC) and differentials
  • Group and Save / Crossmatch
  • Coagulation studies / INR
  • Blood Gases
  • Presence of blood (dipstick / drains)
  • Blood film / morphology

Biochemical tests

  • Abnormal concentration
    • Urea, Creatinine, Bicarbonate / Acid-base related
    • Glucose
    • Electrolytes: Sodium, Potassium, Chloride
    • Electrolytes: Calcium, Magnesium, Phosphate
    • Haematinics, other minerals
    • (iatrogenic) - Drug levels
    • Osmolality
    • Dipstick tests
  • Abnormal rate
    • eGFR
    • 24h studies
  • Abnormal presence
    • General / Reactive markers (e.g. CRP)
    • Specific markers (e.g. Troponin, PSA)
    • (non-iatrogenic) drug levels / Toxins

Microbiological tests

  • Bacterial cultures (blood, urine, pus, aspirate etc) - Microscopy, Cultures and Sensitivity
  • Serology (e.g. Hepatitis Screen, HIV etc)
  • Tests specific to organism and toxins (e.g. monospot)

Immunological tests

  • Evidence of Immunity or previous exposure
  • Evidence of autoantibodies
  • Evidence of allergy

Endocrinological tests

  • Hormones
  • Enzymes
  • Presence of abnormal proteins

Generic Screens and Profiles, vs Specific markers

  • Screens: e.g. Confusion screen, Infection screen, Coagulation screen, Autoimmune screen, Fertility screen, etc.
  • Profiles: e.g. Liver, Lipid, Thyroid, Kidney, Pancreas, Adrenal, Ovaries/Testes, Prostate
  • Specific markers for suspected disease (e.g. tumour markers)

Observation (macro vs microscopic)

  • Macroscopic observation (e.g. ESR, porphyria, cloudy urine, dipstick etc)
  • Microscopic observation
  • Cytology
  • Histology

Genetic Tests

  • DNA based
  • Phenotype-Expression based

Assessments of function and performance. e.g:

  • (extended) vital signs under normal or controlled circumstances (e.g. Peak flow post neb / Postural BP drop)
  • ECG / 24h ECG / Treadmill / 24h BP
  • Lung Function tests / peak flow
  • EEG and nerve conduction studies
  • Excretion (Glucose tolerance test, Shilling's test) or Suppression tests (dexamethasone, synacthen etc).
  • Mental function (e.g. Mini Mental Test)

Image acquisition techniques

  • 2D Radiographs (with or without contrast) +/- digital processing (e.g. subtraction)
  • Ultrasound
    • External
    • Local (e.g. / Oesophageal and PV / PR scans)
    • Functional (such as echo)
    • Doppler studies
  • CT with or without contrast -- including specialised: CTPA / CTKUB / HRCT / Functional CT etc.
  • MRI (with or without contrast) -- including specialised / functional studies
  • Radionuclide Scans (VQ, DEXA, PET/SPECT, MUGA, Thyroid, Full-body studies (e.g. tumour detection)
  • Other / specialised imaging (e.g. OCT, Thermography)
  • Medical Illustration (i.e. photos -- e.g. in monitoring a cellulitic rash)

Direct Visualisation techniques. e.g.:

  • Medical Illustration (as above)
  • Endoscopic
  • Slit lamp etc

Invasive / procedural, e.g.:

  • Angiogram
  • Percutaneous TransHepatic Cholangiogram

Special Diagnostic tests and procedures

  • (Usually vaguely conforming to the previous categories anyway)
  • e.g. Mantoux test - conforms to immunology / assessment of (immune) function / Direct observation of skin response / invasive

Differential Diagnoses checklist

  • Challenge the existing diagnosis / "label"
  • Consider differentials based on Aetiology (Serious / Common / Systematic)
  • Consider Variants
  • Pitfalls and conditions presenting in a similar manner
  • Isolated vs part of a broader syndrome
  • (other)

Intervention Profiles

  • Aims

    • Stabilization
    • Therapeutic
    • Diagnostic
    • Prognostic
    • Palliative
    • Rehabilitative
    • Preventative
  • Indications

  • Contraindications

  • Alternatives (advantages / disadvantages)

  • Consent

  • Preparation

  • Procedure

  • Potential Complications

  • Common pitfalls

  • Intended outcome

  • Effectiveness of intervention

  • Necessity and differentiation potential of intervention

  • Post-procedure checks / instructions / follow-up / maintenance

  • Cost


Management Choices / Pathways / stages Immediate

  • Acute (i.e. Stabilize)
  • Conservative
  • Medical
  • Surgical

Comprehensive

  • Preventative (Primary or Secondary Prevention)
  • Follow-up
  • Rehabilitative
  • Social
  • Palliative

Hierarchy of Management priorities

  • Stabilisation (ABCs)
    • Airway
    • Breathing
    • Circulation
    • Disability
    • Exposure / Secondary Survey
    • Full History / Examination
    • Go through old notes and charts (especially drug charts)
    • Help (call for help / review / reassess ABCs)
    • Investigations (bloods, ECG, CXR, gases, etc)
  • Address Symptoms (i.e. supportive)
  • Address Aetiology / pathophysiology (i.e. specific)
  • Address Risk Factors
  • Address Complications

ABC: Airway Management

  • Open, remove obstruction / use sucker if necessary
  • Head tilt, Jaw thrust, Chin lift
  • Oropharyngeal, Nasopharyngeal, Intubation, Cricothyroidotomy/Tracheostomy
  • Patient’s Position (eg. Upright/Recovery/Immobilized spine)

ABC: Breathing Management

Learn:

  • Respiratory Rate and effort
  • Sats
  • Chest Examination
  • CXR
  • Arterial Blood Gases

Act:

  • Oxygen +/- Nebulizers
  • Ventilation?

ABC: Cardiovascular Management

Learn:

  • Monitor Vital signs: Pulse, Blood pressure, Capillary refill, Temperature, Urine output. (+Resp. rate and sats)
  • ECG

Act:

  • Fluid rescusitation / fluid challenge / transfusion / antibiotics

Disability assessment (during A&E / acute assessment / stabilization)

  • GCS / AVPU
  • Pupils / Limbs / Speech (+/- Swallow assessment)
  • Don’t ever forget the glucose
  • Analgesia

Complications

  • Common vs uncommon
  • Serious vs non-serious
  • Immediate vs delayed

Prognosis "What can you do about it doctor?" (i.e. role of / response to treatment):

  • Self limiting; minimal treatment input required
  • Treatment reliant but responsive
  • Resistant to treatment

"What's going to happen?" (i.e. treatment outcome):

  • Curable
  • Manageable
  • Slow down rate of progression / reduce symptoms

How long / how often:

  • Acute (e.g. days)
  • Medium term (e.g. weeks-months)
  • Chronic
  • Recurrent

How do we know this information?

  • Concluded from epidemiological evidence
  • Differentiated from formal classifications
  • Empirical from clinic or follow-up experience (last resort!)

Tasos Papastylianou © 2006