Understand 1st year medicine

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BMI Body Mass Index = Weight (kg) / (Height (m))2  
18.5 - 25 is normal
25-30 is overweight
30 - 40 is obese
>40 is severely obese

DM (Diabetes mellitus)

Fasting plasma glucose >7mmol/L
Random plasma glucose >11
HbA1c > 7%

  • Glycated hemoglobin (Hb + Glucose → Glycated Hb)
    • Glycated byproducts have long half-life
      • AGE - advanced glycation end-product
        • peripheral neuropathy: attack myelin
        • alzheimer’s: form b-amyloid deposits
        • stroke
        • inflammation by inducing nf-kb pathway
      • Carcinogen - acrylmide made
  • for long term monitoring - indicative of plasma glucose level over 2-3 months period
  • If high, increased risk of CV disease, nephropathy, retinopathy

MAP Mean Arterial Pressure or BP Blood Pressure = CO Cardiac Output x TPR Total peripheral resistance
CO (Cardiac output) = HR (Heart rate) x SV (Stroke volume)

Confidentiality
Why it is important
  • Respect patient
  • Trust

Exceptions where one needs to inform ‘relevant authorities’ (e.g. health protection agency) based on legislation and doctor’s “duty to warn” (doctor liable for injury caused to another where the doctor had the opportunity to warn but failed to do so)
  • If welfare of children is at stake
  • Relates to serious crime
  • Public interest (Public good > Individual’s right of confidentiality)
  • Court order

Examples
  • Notifiable disease
    • Public health act (infection disease and control of diseases)
  • unfit to drive

Principles of WHO screening of the condition
  1. Condition is an important health problem.
  2. Treatment for the condition
  3. Test for the condition
  4. Test is acceptable to the population
  5. Agreement on whom to treat

Screening

benefits of screening: prevent death, less likely to have mastectomy for breast cancer
not-so-good about screening: radiation, false negative, false positive (look normal and recalled for more test), anxious

Breast cancer
most common cancer in women
increased risk with aging

Breast screening
Xray (mammogram)
between 50 and 70 are invited for screening every 3 years
after 70 still welcome just phone for appointment.
Procedure
  1. undress from waist up
  2. one breast at a time between 2 plates. 2 pictures per breast and press firmly
  3. takes about half an hour
  4. uncomfortoable but only for a while
  5. result within 2 weeks
1/20 called back b/c more test needed (e.g. more mammogram, ultrasound scan, needle biopsy with local anesthetic)
mammogram record kept for at least 8 years
digital mammography (computer screen).

being breast aware: get to know your own body to spot for changes - lumps, dimpled skin, pain, nipple discharge

Most common breast cancer: ductal carcinoma in situ (DCIS) - early form


Treatment for breast cancer: lumpectomy (removal of affected tissue) and radiotherapy, mastectomy (complete breast removed) and breast reconstruction, chemotherapy.

Cervical screening
screening for 25-64
results of screening within 2 weeks
25-64 every 3 (if age <50) or 5 (if age >50) years
  • the reason why women under 25 is not offered screening is b/c research shows it could affect future childbearing (risk outweighs benefit) and cervical cancer is very rare
65+ for those who have never been screened or had recent abnormal

HPV (Human papilloma virus) vaccination
  • given to all 12 and again for 18
  • though vaccinated, still advised to continue accepting cervical screening as it does not prevent all types of cancer

Risk factors for cancer
HPV found in almost all cervical cancers
  • HPV vaccine covers 75% of cervical cancer (HPV16 and 18).
sexually active, many sexual partners, immunosupression, oral contraceptive, smoking, non-attendance for screening
if never had sex - chance of developing cervical cancer is almost nil... . lesbian sex at lower risk but still possible.

Procedure
  1. undress waist down
  2. speculum to open vagina and use brush to collect  cervix cells - only mildly uncomfofrtable
  3. Cells are then put into vial containing preservative fluid (liquid based cytology) which is sent to lab to centrifuge to remove e.g. mucus
  4. slide examined to determine the grade
  5. recall 3 or 5 (3 if less than 50, 5 if greater than 50) years if negative (i.e. no abnormalities) , abnormal (borderline changes or different stages of dyskaryosis [epithelial cells in external cervical os abnormal nuclei] - CIN1-3)
  6. hpv triage: if borderline or dyskaryosis - automatically have hpv test on sample (if found, colposcopy, if not found, routine screening)

colposcopy - outpatient microscope to examine cervix, biopsy may be taken

treatment using laser ablation or cold coagulation or loop diathermy  (most effective but causes problems if later preg. e.g. premature delivery), usually no hysterectomy (as the aim of treatment is to preserve their fertility!), chemo or radio if extensive

prostate cancer
second most common cause of cancer (after lung) in male
rare if young, greater risk in african american.
  • radiotherapy (e.g. brachytherapy (radioactive seeds)) , prostatectomy (sfx = impotence, incontinence)


prostate screening
  • controversial... usefulness in screening?
  • psa in blood. raised PSA (Prostate specific antigen) can be an indication but can also be caused by prostatiis, urinary infxn
  • 2/3 with raised psa do not have prostate though the higher it is the more likely
  • preparation: before PSA test, no active UTI, ejaculation, exercise vigorously, prostate biopsy
  • if definitely raised, prostate biopsy to confirm - sampling through rectum

Mental health problem: any disorder or disability of the mind

Mental health act
  • Even if sectioned, they have the right to be explained about treatment
  • All people aged 16 and over are presumed in law to have the capacity to consent to treatment unless there is evidence to the contrary

Treatment under section orders
Sectioning procedure
  • Social worker
  • Doctor
  • GP
  • Section 2: 28 days
    • for assessment
    • Approved mental health professional (AMHP - social worker) and 2 doctors (psychiatrist and GP)
  • Section 3: 6 months (renew 1 year)
    • for treatment
  • Section 4: For 72 hours - Emergency - if delay put others/self at risk
    • no appeal
    • for assessment

Discharge if
  • Mental Health improves
  • Mental health tribunal
  • Relative
    • doctor can ban

Aftercare service
  • Remain as informal patient in hospital
  • Draw up care plan

Competence to consent

Assessing Capacity to consent
  • Can understand and remember treatment info.?
  • can evaluate?
  • can communicate their wishes

Adult
Any adult (>16) are presumed in law to have capacity to consent to treatment
  • If not competent no-one can give consent on their behalf and clinicians can provide treatment if it is of the patient's best interests

<16 - Gillick competence
young people should be involved as much as possible in their care pathway
whether a child (16 years or younger) able to consent to own treatment, without the need for parental permission or knowledge.
  • need to establish whether child is legally competent
  • if not, consent will need to be obtained from parent unless emergency (no consent needed to save the life or prevent deterioration)
    • legally just need to consult 1 parent
    • but in practise better to involve both
Should not be assumed that those with learning difficulty can’t make competent decision - should present info in appropriate way
  • If a competent child requests that confidentiality is maintained, this should be respected unless the doctor considers that failing to disclose information would result in significant harm to the child.


Organ Donation

Donations to specific people: Medical and surgical preparation
Altruistic donations: Donation to any person
  • psychiatric assessment, medical and surgical preparation.

Priority
Organs donated from children go to child to ensure best size match
If no child recipients, to adults

Points score
  • Waiting time
  • Well Tissue match and young age
  • Age difference between donor and patient (favor close age match)
  • Transportation time (further - less likely)

Semen made from:
  • Seminal vesicle 60% - alkaline + fructose + prostaglandin (stimulate SM contrxn in resp. tract) + fibrinogen (forms temporary clot in vagina)
  • prostate 30% - acidic
  • epididymis 6% - storage and maturation to form tail
  • cowper 3%
  • testes 1%



Genes in population

Freq. of allele A = p
Freq of allele a = q
p + q = 1

GenotypeFreq
AAp2
aaq2
Aa2pq (aA and Aa)


For recessive condition: If probability of an affected (i.e aa) is f, gene frequency for the recessive allele (q)  is  sqrt f
p + q = 1 thus p = 1-q = 1 - sqrt f

Carrier frequency is 2pq

Chance of being carrier = ½ x Prob. that mom is carrier x ½ x Prob. that dad is carrier → to make Aa


Proband: particular subject (person or animal) being studied