Archive for December 2011

Ophthalmology Powerpoint Presentations 2

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Acromegaly

Acromegaly

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Acromegaly    YQ54C8JKYS4B
Acromegaly, pituitary, hypophysis
Acromegaly is a disorder that occurs due to an excess secretion of growth hormone (GH)

Epidemiology:
  • Prevalence is approximately 40-60 million
  • Affects M: F with a ratio of 1: 1
  • Mainly affects people between the ages of 30-50 years
Pathophysiology:
  • GH (or somatotropin) is secreted by the anterior pituitary gland
  • GH stimulates soft tissue and skeletal growth indirectly through the secretion of insulin like growth factor-1 (IGF-1) from the liver.
  • The production of GH is regulated by GH-releasing hormone and GH-inhibiting hormone (somatostatin), both released from the hypothalamus
  • Acromegaly occurs due to hyper secretion of GH
  • 99% of time this occurs from a pituitary tumour 
  • Pituitary tumours are almost always benign, and divided into macroadenoma (>1cm) and microadenoma (<1cm)
  • Rarely ectopic secretion of GH-releasing hormone occurs from carcinoid tumours
Clinical features:
  • If excess GH secretion occurs before epiphyses have fused, then gigantism results
  • Most commonly though GH releasing pituitary tumours occur in adults, leading to acromegaly
  • Clinical features occur due to excess hormone secretion, local pressure, and hypopituitarism.
Symptoms:
  • Sweating
  • Headache (due to local pressure)
  • Increase size of hands and feet (increase ring and shoe size)
  • Oligo/amenorrhoea
  • Infertility
  • Proximal muscle weakness
Signs:
  • Coarsening of facial features
  • Prominent supra-orbital ridges
  • Prognathism (prominent lower jaw)
  • Increased interdental spacing
  • Macroglossia (enlarged tongue)
  • Doughy spade like hands
  • Carpel tunnel syndrome
  • Hoarse voice
Investigations:
Random GH measurements – GH is secreted in a pulsatile manner, with secretion increasing in stress, sleep and puberty, and reducing in pregnancy. Therefore random GH measurements are not very useful for diagnosis
 Serum IGF-1 – This can be used as a screening test, In most cases serum IGF-1 levels correlate with GH secretion over the past 24 hrs
    OGTT  - This is the diagnostic test for acromegaly. Normally rising levels of glucose inhibit GH secretion, thus in the OGTT, GH levels should be undetectable (< 2mU/L) once glucose is administered. However, in acromegaly there is a failure to suppress GH secretion.
    MRI of pituitary fossa
    Investigate any potential complications
        Full pituitary hormone profile  (hypopituitarism)
        Visual fields and acuity   (bitemporal hemianopia can occur due to compression of optic chiasm by pituitary tumour)
        Fasting glucose   (IGT)
        ECG, echo (Heart failure)

Management:
1. Surgical:
  • Trans-sphenoidal surgery
  • First line treatment
  • High cure rates for microadenoma
  • Post op  (3 months) investigations needed.
  • Measure GH day curve or repeat OGTT
  • Pituitary function tests to check for hypopituitarism
  • If GH remains high, further second line medical or radiotherapy needed
2. Medical:
  1. Somatostatin analoges: e.g. lanreotide, octreotide (IM injections) 
  2. Side effects:
  • Pain at injection site
  • GI- N&V, abdominal pain, flatulence, diarrhoea, gallstones
  • Impaired glucose tolerance
  • Highly selective GH receptor antagonist (pegvisomant [ s.c injections] ) is available for patients with inadequate response to surgery, radiation or both and to treatment with somatostatin analogues
3. Radiotherapy:
  • If surgery is inappropriate
  • Adjuvant to surgery
Follow up
Yearly
GH and IGF-1 measurement +/- OGTT
Visual fields
Clinical photos
Cardiovascular assessment. Aim for GH < 5mU/L to reverse mortality risk


Complications

    Diabetes Mellitus (10%), Impaired glucose tolerance (25%) [GH is counter regulatory to insulin]
    Vascular
        HTN
        Cardiomyopathy
        Heart failure
        Increased risk of IHD and stroke
    Osteoporosis
    Obstructive sleep apnoea [due to soft tissue swelling in larynx]
    Malignancy- It is still controversial whether acromegaly increases risk of developing colonic polyps and colonic carcinoma
    Hypopituitarism +/- local mass effect


Prognosis

    High mortality if untreated
    Mortality increased by 2-3 fold mainly due to cardiovascular risk



Examining for Acromegaly
Very common station in OSCEs although the condition itself is rare. Usually in OSCE the patient will have been treated, and thus the disease is not active, but many of the physical feature may remain.

Hands

    Size of the hands – compare to your own. Often grossly enlarged
    Skin fold thickness – again, compare to your own. Often increased in acromegaly
    Palm – feel for boggyness of the palm
    Sweating – feel the palms for sweating
    Thenar eminence / median sensory distribution – check for thenar eminence wasting and sensation on the lateral 3 ½ fingers (carpal tunnel syndrome)
    Proximal myopathy – check the power in the upper arm



Face

    Prominent supra-orbital ridges
    Large tongue
    Large ears
    Prognathism – an ‘underbite’ – the lower teeth protrude out below the upper ones



Visual Fields

    Check the visual fields


Cardiovascular system

    Check the BP (may be raised)
    Check for cardiomegaly

o   Displaced apexed beat
o   Raised JVP

Epistaxis

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nosebleed, nose bleed, epistaxisMost nosebleeds arise from little’s area on the nasal septum. Five arteries anastomose to form little’s area:
1) Anterior Ethmoid Artery
2) Posterior Ethmoid Artery
3) Sphenopalatine Artery
4) Great Palatine Artery
5) Superior Labial Artery

Causes
Local:
  • Idiopathic
  • Trauma – nose picking, nasal fracture
  • Drug Induced – Nasal sprays, anticoagulants
  • Foreign Body
  • Rhinitis
Systemic:
  • Clotting disorders
  • Hypertension
  • Vasculitis (e.g Wegener’s Granulomatosis)
  • Hereditary Haemorrhagic Telangiectasia (a.k.a Osler-Weber-Rendu disease, an autosomal dominant condition causing oral telangiectasia and epistaxis)
Management
  • Airway, Breathing, Circulation!
  • Gain IV access with a large bore cannula
  • Send bloods for FBC, Group & Save and a clotting screen
  • Give IV fluids
  • Get the patient to sit upright, lean forwards and pinch the soft part of the nose
  • Advise the patient to spit out any blood in the mouth
  • Monitor pulse and blood pressure for signs of hypovolaemic shock
  • If a bleeding vessel is visible consider cautery with silver nitrate
  • Failing this pack the nose with Merocel nasal packs
  • If examination suggests a posterior haemorrhage (i.e from the sphenopalatine artery) then try a balloon catheter to compress the bleeding vessel
  • If this fails to stop the bleeding then the patient may need surgical ligation of the sphenopalatine artery

Written by Rachel Smith

    Ear Nose Throat (ENT) – Power Point Presentations

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    Dupuytren's Contracture

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    Dupuytren's Contracture

    Dupuytren's Contracture is a progressive flexion deformity of the fingers, typically affecting the 4th (ring) finger. Also commonly affects the little finger, and rarely the middle finger. It is a result of contracture and fibrosis of the palmar aponeurosis.
    It is usually painless, and can affect one or both hands.

    Dupuytren's Contracture
    Epidemiology
    -          More common in men (10:1)
    -          Increases after age 45
    -          Tends only to affect those of Scandinavian and Northern European origin, as well as those from the Iberian peninsula and Japan.

    Etiology
    -          It is believed that in about 70% of cases it is the result of a genetic disorder whereby susceptible individuals who are subsequently exposed to further risk factors.  These factors can include:
    o   Liver disease
    o   Diabetes
    o   Epilepsy
    -          It can also be ideopathic

    Presentation
    -          Often a tender nodule on the palm is the first sign
    -          Deformity is progressive and follows later
    -          Pain subsides as it progresses
    -          Eventually the whole hand becomes arched, and there is contracture of the MCP and interphalangeal joints

    Management
    -          Steroid Injections are useful in early presentations of a tender nodule, and can prevent the formation of the contracture
    -          Surgery is indicated if:
    o   The hand can’t be placed flat on a flat surface
    o   There is contracture of the PIP joints
    -          Surgery involves careful removal of the affected palmar aponeurosis around neurovascular bundles (which are left behind). Recurrence can occur particularly if the dissection for removal is not adequate, and/or commonly if the patient is young at the time of surgery
    -          Injected collagenase – is a new treatment that has been shown to reverse contracture in some patients but is not widely used.
    Dupuytrens Contracture Dupuytren's Contracture Post Surgery
    Dupuytren's Contracture Dupuytren's Contracure after surgery

    Notes by Tom Leach

    Endocrinology Powerpoint Presentations 1

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    Bacterial Vaginosis (BV)

    Bacterial Vaginosis (BV)

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    Bacterial Vaginosis (BV) std


    THE most common cause of pathological vaginal discharge. It can be caused by an overgrowth of many types of bacteria, usually anaerobes. There is also often a decrease in the number of lactobacilli. It is not sexually transmitted.



    Epidemiology

    - Affects 10% of women in the UK, but most cases are asymptomatic

    Presentation

    - A smelly (fishy) discharge, usually white / gray in colour. This idscharge is made up of waste products produced by the colonising anaerobes.
    - Vaginal itch (not in all cases)
    - Not usually inflamed

    Investigations

    - Whiff test (yes, really!) – potassium hydroxide (KOH) is added to a sample of the vaginal discharge. If a strong fishy odour is produced – the test is positive for bacterial vaginosis
    - pH - >4.5
    - Triple swabs (chlamydia, gonorrhoea, and a ‘general’ swab for culture)
    o Microscopy – reduced levels of lactobacilli, and increased levels of other bacterial agents, leukocytes absent, presence of clue cells
    o Culture – to define the predominant causatory agent

    Differentials

    Trichomoniasis is the only other likely cause of an offensive discharge, but this is usually yellow, and on microsocpy shows the prescence of protozoa with flagella
    Risks
    - Increased risk of pre-term labour
    - Intra-amniotic infection
    - Increased susceptibility to HIV
    - Post-termination sepsis

    Treatment

    - Metronidazole PO – one-off dose – 2g
    - Clindamycin – 2% cream – apply once at night to the vagina for 7 days
    o If recurrent problems, then treating the partner may resolve the situation

    Written by: Tom Leach

    Dental Lecture Notes

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    Obstetrics & Gynecology Powerpoint Presentations 1

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    Obstetrics & Gynecology Powerpoint Presentations

    Click on the below to download: 

    Educational Tutorials: Categories



    Power Point Presentations of World Experts

    www.obgyn.net/educational-tutorials/educational-tutorials.asp
    there are many of them , the site is full of presentations
    But there is copyright on it.

    Obstetrics & Gynecology Powerpoint Presentations
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    Click on the Button to Print/PDF

    Left Anterior Fascicular Block

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    Cardiology Revision Notes - Left Anterior Fascicular Block

    Left Anterior Fascicular Block - CardioNotes

    Characteristics

    Normal activation of the left ventricle proceeds down the left bundle branch, which consist of two fascicles the left anterior fascicle and left posterior fascicle. Left Anterior Fascicular Block (LAFB), which is also known as Left Anterior Hemiblock (LAHB), occurs when a cardiac impulse spreads first through the left posterior fascicle, causing a delay in activation of the anterior and lateral walls of the left ventricle which are normally activated via the left anterior fascicle.
    Although there is a delay or block in activation of the left anterior fascicle there is still preservation of initial left to right septal activation as well as preservation of the inferior activation of the left ventricule (preservation of septal Q waves in I and aVL and small initial R wave in leads II, III, and aVF). The delayed and unopposed activation of the remainder of the left ventricle now results in a shift in the QRS axis leftward and superiorly, causing marked left axis deviation. This delayed activation also results in a widening of the QRS complex, although not to the extent of a complete LBBB

     

    Criteria for LAFB

    • Left axis deviation (usually between -45° and -90°), some consider -30° to meet criteria
    • QRS interval < 0.12 seconds
    • qR complex in the lateral limb leads (I and aVL)
    • rS pattern in the inferior leads (II, III, and aVF)
    • Delayed intrinsicoid deflection in lead aVL (> 0.045 s)

     

    Exceptions

    It is important not to call LAFB in the setting of a prior inferior wall myocardial infarction which may also demonstrate left axis deviation due to the initial forces (Q wave in a Qr complex) in leads II, III, and aVF. As opposed to LAHB, the left axis shift is due to terminal forces (i.e., the S wave in an rS complex) being directed superiorly,

     

    Effects of LAFB on Diagnosing infarctions and Left Ventricular Hypertrophy

    LAHB may be a cause of poor R wave progression across the precordium causing a pseudoinfarction pattern mimicking an anteroseptal infarction. It also makes the electrocardiographic diagnosis of LVH more complicated, because both may cause a large R wave in lead aVL. Therefore to call LVH on an EKG in the setting of an LAHB you should see the presence of a “strain” pattern when you are relying on limb lead criteria to diagnose LVH.

     

    Clinical Signficance

    • It can be seen in approximately 4% of cases of acute myocardial infarction
      • It is the most common type of intraventricular conduction defect seen in acute anterior myocardial infarction, and the left anterior descending artery is usually the culprit vessel.
      • It can be seen with acute inferior wall myocardial infarction.
    • It also associated with hypertensive heart disease, aortic valvular disease, cardiomyopathies, and degenerative fibrotic disease of the cardiac skeleton.

     

    References

    1. Mirvis DM, Goldberger AL. Electrocardiography. In: Braunwald E, Zipes DP, Libby P, eds. Heart disease: a textbook of cardiovascular medicine, 6th edn. Philadelphia: WB Saunders; 2001:82–125.
    2. Surawicz B, Knilans TK. Chou’s electrocardiography in clinical practice: adult and pediatric, 5th edn. Philadelphia: W.B. Saunders; 2001.

    Orthopedics PPT Presentations 1

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    Compartment Syndrome

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    Orthopedics: Compartment Syndrome
    This is a syndrome that results from swelling of a muscle. The muscle is retained in its fixed volume fascia, however, and thus the swelling of the muscle causes occlusion of the blood supply. this can result in infarction, and can cause an ischaemic contraction known as Volkmann’s Ischaemic Contracture.
    It typically occurs in the forearm and calf, but can also occur in the thigh and foot.

    Compartment Syndrome


    Causes

    -          Trauma – compartment syndrome is often a complication of fracture.
    -          Continued pressure on a limb – e.g. lying for hours in the same position on the same limb – often seen in drug and alcohol abuse. 

    Pathophysiology

    -          Swelling of the muscle – usually as a result of post-traumatic bleeding and oedema.
    o   Initially only venous flow is disturbed, and arterial flow (due to its greater pressure) still occurs.
    o   Eventually, the pressure within the compartment exceeds the arterial pressure, and the muscle begins to undergo ischaemia.
    § The main arteries in the compartment have a higher pressure than the arterioles, and thus these may not be occluded until late on, if at all
    § Other structures close by are also affected by the ischaemia – e.g. nerves, but the nerves are not affected until the pressure is very high!
    § This means that distal pulses and neurological exam are usually normal until VERY LATE ON!
    ·         If there are reduced or absent pulses, then it is likely the diagnosis is too late to stop severe ischaemic damage.

    Clinical features and diagnosis

    -          Often co-exists with fractures
    -          You should be suspicious if there is:
    o   Pain increasing over time – despite appropriate analgesia and joint immobilisation
    -          People particularly at risk are children/young adults with:
    o   Tibial shaft fractures
    o   Forearm injuries
    o   Crush injuries
    -          There is often increased pain on passive flexion and extension of the fingers and toes of the affected limb
    -          Measure compartment Pressure:
    o   <30mmHg is normal
    o   >40mmHg is high
    o   Compare diastolic arterial and compartmental pressures – the difference needs to be >30mmHg for adequate perfusion.
    o   In children – compartment pressures are not routinely monitored

    Treatment

    -          Fasciotomy – of the muscle compartments involved. Do it as soon as possible! To minimise the risk of irreversible ischaemia.
    o   If there is any doubt over the diagnosis, perform fasciotomy anyway!


    Notes by Tom Leach

    Carpal Tunnel Syndrome (CTS)

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    Orthopedics: Carpal Tunnel Syndrome (CTS)
    Epidemiology and Aetiology
    -          More common in women
    -          Typical presentation at age 30-50
    -          Associated with gout, pregnancy, the pill, premenstrual state, rheumatoid arthritis, diabetes, acromegaly, obesity, amyloidosis
    -          Some believe that jobs that involve repetitive flexing of the wrist may be involved.
    o   RSI – repetitive strain injury – is a fallacy and doesn’t actually exist! There is usually another underlying diagnosis.
    -          Most cases are ideopathic
    Carpal Tunnel Syndrome

    Pathology
    -          Compression of the median nerve as it passes through the carpal tunnel (under the flexor retinaculum)
    Signs and symptoms – are those of median nerve compression:
    -          Wasting of the thenar eminence (the chunky muscle on the palmar aspect of the base of the thumb) – is often a late sign
    -          Parasthesia of the lateral 3½ fingers (thumb, forefinger and middle finger)
    -          Pain / tingling in the lateral 3 fingers
    o   Pain is often worse at night and may wake the patient. It is often a burning or aching sensation.
    -          The median nerve also supplies the lateral part of the palm but typically, this is spared as this branch of the median nerve does not pass through the carpal tunnel.

    Examination
    -          Look for wasting of the thenar eminence
    -          Check sensation on the lateral 3½ fingers
    -          Phalens Test – ask the patient to hold their wrists in a flexed position for 1-2 minutes. May elicit / exaggerate typical symptoms
    -          Tinel’s Test – tap over the medial aspect of the inside of the wrist. Can induce tingling sensations. Less likely to elicit signs than Phalens
    o   “Tinels – Tapping, Phalens – Flexing”

    Investigations
    -          Diagnosis is usually clinical, but occasionally in difficult cases, nerve conduction may be performed.

    Management
    -          Conservative – occasionally simple life-style changes (e.g. placement of computer keyboard) may be beneifical.
    -          Splint – can be worn at night to reduce nocturnal symptoms, and many patients may also wear it during the day
    -          Pain relief – is typically in the form of NSAIDs
    -          Carpal Injection – hydrocortisone acetate – can be used if other methods have failed to control symptoms. Inject just dorsal to the wrist crease. Provide pain relief for approximately 1 month. Longer acting pain relief is no more effective than placebo.
    o   May cause a sensation of shooting and tingling if you touch the nerve. If this is the case, you are in the wrong place! You are not aiming for the nerve itself, but for the flexor tendons.
    o   Wearing a splint for a few days after injection can reduce the symptoms induced at time of treatment
    -          Surgical decompression can be used for patients who still fail to respond. This can be open or endoscopic surgery.
    o   Wearing a splint for a few days after injection can reduce the symptoms induced at time of treatment

    Notes by Tom Leach

    Elhers-Danlos Syndrome (EDS)

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    Rheumatology: Elhers-Danlos Syndrome (EDS)
    Elher-Danlos syndrome is an inherited connective tissue disorder caused by defective collagen synthesis. Symptoms vary widely between individuals. Some may be hardly effected, whilst other live severely restricted lives.


    Elhers-Danlos Syndrome (EDS)


    Epidemiology and Etiology
    • Several types of the disease (5 main types, + some rarer ones), inheritance depends on the type. Most are autosomal dominant, but some are recessive
    • Thought to affect about 1 in 5000 births
    Pathology and clinical findings
    • Defective collagen synthesis, resulting in insufficient and/or ineffective collagen. Affected organs vary depending on the type of the disease, although there is often some degree of all the features below, regardless of what type:
      • Classical (common) – hyperelasticity of the skin
      • Hypermobility type (common) – hypermobility of joints. Joints are prone to sprain, dislocation, effusion and subluxation
      • Vascular type (rare) – easy bruising, aneurysms
      • Ocular-kyphoscoliotic type (rare)– weak sclera, predisposing to perforation of the globe, and kyphoscoliosis of the spine.
      • Arthrokalasis (rare)– characterised by bilateral congenital dislocation of the hip
      • Other types – extremely rare (e.g. <50 reported cases worldwide)
    • Other signs and symptoms
      • Flat feet
      • Poor healing / thin skin particularly scar tissue – can be difficult to suture in surgery as the skin just rips
      • GI bleeds / perforation
      • Hypotonia
      • High, narrow palate
      • Molluscoid pseudotumours – fleshy outgrowths at the site of pressure points
      • Aneurysm
      • Increased risk of pneumothorax
     
    Diagnosis
    • Usually clinical
    • Usually a FH
    Prognosis and Treatment
    • Life expectancy is usually normal
    • However, some complications are potentially lethal (e.g. ruptured aortic aneurysm)
    • There is no particular treatment
    • Management may involve:
      • Minimising the risk of trauma – this could be with the use of protective clothing / padding
      • Extra precautions to ensure haemostasis during surgery – also watch out for suturing wounds – don’t leave the skin under excessive tension
      • Extra precautions during pregnancy and delivery
      • Genetic counselling – particularly if planning pregnancy
       

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