Thursday 20 March 2014

Mnemonics... Contents of the Spermatic Cord

The contents of the Spermatic Cord can be easily remember with the Rule of 3's.

3 arteries: Testicular Artery, Cremasteric Artery, Artery to Vas
3 veins: Pampiniform plexus, Cremasteric Vein, Vein of Vas
3 nerves: genital branch of genitofemoral nerve, sympathetics, ilioinguinal nerve (technically runs outside the spermatic cord.
3 fascias: External Spermatic Fascia, Cremasteric fascia, Internal Spermatic fascia
3 others: Vas Deferens, Lymphatics, Tunica Vaginalis

Credit to instantanatomy.net


Saturday 15 March 2014

For your information... Suture materials

Absorbable

Vicryl - Polyglactin 


Monocryl - Poliglecaprone


PDS - Polydioxanone


Catgut - Fibres from intestinal walls of animals


Non-absorbable

Ethilon - Nylon


Silk - Silk


Prolene - polypropylene


Friday 14 March 2014

Question of the Day... Klumpke's Paralysis

This question was taken from the Coventry Oct 2012 Exam.

Question:
What are the roots involved in an inferior brachial plexus lesion?

Answer:
C8 and T1

What is the result of injury to the nerve roots of C8 and T1?
Paralysis of the intrinsic muscles of the hands and flexors of the wrist leads to the classic "claw hand". Metocarpophalangeal joints are extended and interphalangeal joints are flexed due to unopposed reciprocal muscles.

It also results in paraesthesia over C8/T1 dermatome distribution


What other signs may be seen in Klumpke's paralysis?
Klumpke's paralysis is commonly associated with Horner's syndrome as traumatic injury to the lower nerve roots of the brachial plexus can also result in disruption to the sympathetic chain.

What is the most common cause of Klumpke's paralysis?

  • Childbirth - pulling on arm during delivery
  • Forceful, sudden extension of the arm above the head (like a monkey swinging on a tree!)

Thursday 13 March 2014

For your Information... How does CLO test work?

The CLO test is a rapid test for the diagnosis of Helicobacter Pylori, which secretes the enzyme "Urease".


The CLO test takes advantage of this chemical reaction to test for the presence of Helicobacter Pylori. The biopsy specimen from an OGD is placed into medium containing urea and indicator phenol red. When the Urea is hydrolysed by the H. Pylori in the specimen into NH3, the pH is raised and the indicator changes from yellow to RED.

The CLO test works by detecting when the medium becomes ALKALINE due to the ammonia.

This is in stark contrast to the Urease Breath Test, which detects the CO2 (via C13 labelled urea) produced from the reaction.

Wednesday 12 March 2014

Question of the Day... Erb's Palsy

This question was taken from the Coventry Oct 2012 exam.

Question:
What is the position seen in Erb's Palsy?

Answer:
"Waiter's tip" position

What is Erb's palsy?
Erb's palsy is a lower motor neuron lesion that common occurs when the head and shoulders are forced apart, stretching and tearing the upper roots of the brachial plexus.

Which roots are affected in Erb's Palsy?
C5 and C6

Why does the patient present with the "Waiter's tip"?
Paralysis of the deltoid prevents the arm from being raised.
Paralysis of the biceps brachii and brachialis (flex and supinate elbow) means that the arm is limp and the forearm is pronated.

Tuesday 11 March 2014

For your information... Chvostek's and Trousseau's Sign

This question was taken from the Sheffield Feb 2014 exam.

Both Chvostek's and Trousseau's sign are clinical signs elicited in patient's who have Hypocalcaemia

Chvostek's Sign
There are 2 variations to this sign but the most common practiced variation is where the practitioner uses either a finger or a hammer to tap at the angle of the jaw. In a patient with hypocalcaemia, this results in ipsilateral contraction of some or all of the muscles innervated by the facial nerve.

The technique described above involves using a finger to tap on Point A

Trousseau's sign
A blood pressure cuff is inflated to above systolic blood pressure and sustained for 3 mins. The subsequent lack of blood flow will induce spams of the muscles of the hands and forearms.
  • Flex
    • Wrist and Metocarpophalangeal joints
  • Extend
    • Distal and Proximal Interphalangeal joints
  • Adduct
    • Fingers

Monday 10 March 2014

Mnemonics... Glasgow Criteria

There is a simple mnemonic to remember the Glasgow Scoring system as prognosis for Acute pancreatitis. Just remember to do the scoring within 48hrs of the onset of symptoms. 3 or more requires admission to HD or ITU.

Mnemonic Letter
Criteria
Positive when:
P
Arterial PaO2
<60 mmHg
<8 kPa
A
Age
>55 yrs
N
Neutrophils (WBC count)
<15x109/L
C
Calcium
<2 mmol/l
R
Raised Urea
>16 mmol/l
E
Enzymes (LDH and AST)
LDH >600 iu/l
AST >200 iu/l
A
Albumin
<32g/l
S
Sugar (Serum glucose)
>10mmol/l

Saturday 8 March 2014

For your information... Layers of the Abdominal Wall

Here are the layers of the anterior abdominal wall from superficial to deep:


  • Skin
  • Fascia
    • Camper's - superficial fatty layer
    • Scarpa's - deep fibrous layer
  • Muscle
    • Rectus abdominis
    • External Oblique
    • Internal Oblique
    • Transversus abdominis
  • Transversalis Fascia
  • Peritoneum

The only change from this is below the Arcuate Line when the Internal Oblique and Transversus Abdominis aponeuroses merge and pass superficial to the Rectus muscles. This means that the Rectus Abdominis rests directly on the Transversalis fascia below the Arcuate line.

Friday 7 March 2014

Mnemonics... Branches of the Facial Nerve

The facial nerve can be divided into 2 parts:
  • Intracranial
  • Extracranial
Intracranial branches:
  1. Greater petrosal nerve
  2. Nerve to stapedius
  3. Chorda Tympani
Extracranial branches:
  1. Temporal
  2. Zygomatic
  3. Buccal
  4. Marginal Mandibular
  5. Cervical
There is a simple mnemonic that will help you to remember the extracranial branches of the facial nerve:

The Zebra Bit My Cock

Rollover the image for answers:



Very easy to remember, and fun!

Mnemonics... Branches of the External Carotid Artery

This mnemonic will help you to remember the branches of the external carotid artery.

The Common Carotid Artery arises from the Right Brachiocephalic Trunk on the Right and the directly from the Arch of Aorta on the Left. It then bifurcates into the External and Internal Carotid arteries at the level of C4.



There are 8 branches of the external carotid artery. From proximal to distal the Mnemonic is:

Some Anatomists Like Fornication, Others Prefer S & M

S - Superior Thyroid Artery
A - Ascending Pharyngeal Artery
L - Lingual Artery
F - Facial Artery
O - Occipital Artery
P - Posterior Auricular Artery
S - Superficial Temporal Artery
M - Maxillary Artery

There are others of course, but this is the one I used!


Thursday 6 March 2014

For your information... OGD and dilatation

Oesophago-gastroduodenoscopy is a safe procedure that allows direct visualisation of the upper part of the gastrointestinal tract up to the duodenum.

Indications:
Diagnostic

  • Investigation for anaemia
  • Upper GI bleeding
  • Persistent Dyspepsia
  • Persistent vomiting
  • Dysphagia
  • Odynophagia
Surveillance
  • Surveillance of already diagnosed Barrett's oesophagus
  • Previous gastric/duodenal ulcers
Therapeutic
  • Oesophageal varices
    • Banding
    • Sclerotherapy
    • Epinephrine injections into actively bleeding lesions
    • Insertion of Sengstaken-Blackmore's tube
  • Polyps
  • Removal of FBs
  • Oesophageal stenosis
    • Dilatation
    • Stenting
  • Insertion of PEG tube
  • ERCP

Safety
Most common complication is Sorethroat
Complication rate is 1 in 1000
  • Aspiration
  • Bleeding
  • Perforation
Risk of dilatation
  • Review of 1862 endoscopic dilatations using Savary-Guillard technique showed complication rate of 0.18% for benign strictures and 4.58% for malignant aetiologies (Piotet E, Eur Arch Otorhinolaryngol.  2008 Mar)
  • Certain strictures refractory to treatment and require multiple dilatations
    • E.g. caustic, post-surgical, post radiotherapy strictures.

Wednesday 5 March 2014

Question of the Day... Barrett's Oesophagus

This question was taken from the Glasgow Oct 2013 Exam. It was a communications skills station, however some basic knowledge is still required.

Question:
Mr. Brown has had a Barium swallow that shows a stricture. Please counsel him for OGD and dilatation.

Answer:
Risk factors for oesophageal cancer:

  • Age - >60
  • Gender - Males > Females
  • Smoking and heavy alcohol use - use together increases risk more than either individually.
  • GORD - Gastro-Oesophageal Reflux Disease and Barretts Oesophagus
  • Obesity
  • Previous Radiation
  • Family History of Oesophageal Ca
Clinical Evaluation
  • Gold standard - OGD
  • Imaging - Barium swallow/barium meal
Biopsies taken during OGD are then examined histologically for signs of malignancy.
Staging scans:
  • CT Thorax/Abdomen/Pelvis - to determine distal metastases, espcially LN and liver
  • EUS - provides T staging
Location of the tumour determined by distance from incisors.

Red flags
  • Dysphagia
  • Anorexia/early satiety
  • Jaundice
  • Persistent projectile vomiting
  • Palpable Abdominal Mass
  • Unexplained weight loss >10% body weight or 3kg
  • Anaemia
  • PR bleeding/Melaena/Haematemesis

Barrett's Oesophagus
Definition = metaplasia of lower oesophageal epithelium from normal stratified squamous epithelium to simple columnar epithelium with Goblet cells.
  • Strong association with adenocarcinoma
  • Diagnosis of Barrett's requires histological confirmation of the presence of Goblet cells (Specialize Intestinal Metaplasia or SIM)
Pathophysiology
GORD causes chronic inflammation that causes damage to the cells of the gastro-oesophageal junction.
Epidermal Growth Factor Receptor inhibited by bile acids causes intestinal differentiation.

Biopsy Protocol
The Seattle Biopsy protocol requires 4 quadrant biopsies every 2 cm with targetted biopsies on macroscopically visible lesions. Distal biopsies taken 1st starting 1-2 cm above GOJ and advancing proximally to minimise obscured view from bleeding.





Sunday 2 March 2014

Question of the Day... Femoral Triangle

This question was taken from the Singapore August 2012 Exam.

Question:
Identify the femoral triangle, femoral vein, and the surrounding structures.

Answer:
Boundaries of the femoral triangle:

  • Superior - inguinal ligament
  • Medial - medial border of the Adductor Longus
  • Lateral - medial border of Sartorius
  • Floor (medial to lateral) - Pectineus, Adductor Longus, Iliopsoas
  • Roof - Fascia Lata

  Contents (Lateral to medial)

Nerve - Femoral nerve
Artery - Femoral artery
Vein - Femoral Vein
Empty space - allows expansion of Femoral vein during periods where there is expanded intravascular volume
Lymph nodes - Femoral canal - Deep inguinal lymph nodes (node of Cloquet) and associated Lymph nodes


Just a note on the difference between the mid inguinal point and the mid point of the inguinal ligament.

Mid inguinal point = mid point of line drawn from ASIS to pubic symphysis
  • This is the landmark for the femoral artery

Midpoint of inguinal ligament = mid point of line drawn from ASIS to pubic tubercle
  • This is the landmark for the deep inguinal ring

Saturday 1 March 2014

For Your Information... Refeeding Syndrome

A question on Refeeding Syndrome was asked on the February 2013 London Exam.

Refeeding syndrome

Definition
Metabolic disturbances that result from reinstitution of nutrition to patients who are starved or severely malnourished.

Pathogenesis
During prolonged fasting the body conserves muscle and protein breakdown by metabolising fatty acids to ketone bodies as its main energy source. The liver reduces gluconeogenesis, thus conserving muscle and protein.

Insulin secretion Decreased, Glucagon secretion Increased

Intracellular minerals are severely depleted in order to keep serum levels normal.

Once patients start feeding again the following occurs:

  1. Increased blood sugar stimulates insulin secretion
  2. Glycogen, Fat and Protein synthesis increases
  3. Basal metabolic rate rises
  4. Serum electrolytes move into intracellular space
  5. Serum levels of phosphate, magnesium and potassium are quickly used up in the formation ATP and phosphorylation of carbohydrates
  6. The precipitous drop in serum mineral levels causes cardiac arrhythmias, confusion, coma, cardiac failure and death.
Treatment

  • High index of suspicion
  • Close monitoring of blood biochemistry with adequate replacement either enterically or parenterally if required
  • Thiamine and Vit B Complex supplementation is recommended
  • Limit energy intake for first 3-5 days of commencement of feeding to 50-70% of normal daily requirements