Procedural anatomy Flashcards
Internal jugular vein originates?
Jugular bulb (confluence of the inferior petrosal sinus and sigmoid sinus)
* exits the skull via the jugular foramen
How does the IJ descned in the neck? Relationship to the carotid?
- Descending laterally to the internal carotid and later common carotid in the carotid sheath
- To ICA
◦ At C2 - IJV posterior to ICA
◦ At C3 posterolateral
◦ From C4 anterolateral (common carotid) at the apex of sedilots triangle between he two heads ot the SCM
Where does the IJ terminate
- Terminates behind the sternal end of the clavicle where it joins the subclavian vein to form the brachiocephalic vein - the inferior end dilates to from the inferior bulb of the IJV which has a bicuspid valve permitting blood flow toward the heart
How is the path of the left and right IJ slightly different?
- Right IJ follows a direct course inferiorly to the SVC
- The left IJ courses to the right after it joins the subclavian vein to become the brachiocephalic vein which courses inferiorly as it joins the SVC
Tributaries to the IJ vein (4 primary)
- inferior petrosal sinus - enters superior bulb of the IJV after leaving the jugular foramen
- Facial vein - empties at the level of the hyoid, may receive the superior thyroid, lingual or sublingual veins
- Lingual veins - at the origin of the lingual artery
- Pharyngeal veins - from venous plexus of the pharyngeal wall emptying at the angle of the mandible
- Superior and middle thyroid veins
- The occipital vein may drain into the IJV
Anterior borders of the IJ vein
- Anteriorly - SCM, fascia, platysma, fascia, skin
Posterior borders of the IJ vein
- Posterior - lateral mass of C1 (transverse process), scalene muscles, cervical plexus, sympathetic chain, phrenic nerve, vertebral vein, 1st part o subclavian artery, and lung pleura (thoracic duct on left)
Medial borders of IJ vein
- Medially by internal carotid, thyroid, trachea, oesophageal
Lateral borders of the IJ vein
- Lateral - fascia, skin, SCM
Name 4 major relationships of the IJ vein and describe their relative passage
- To ICA
◦ At C2 - IJV posterior to ICA
◦ At C3 posterolateral
◦ From C4 anterolateral (common carotid) at the apex of sedilots triangle between he two heads ot the SCM - Vagus nerve - posteriorly in the carotid sheath between the carotid and the IJV; 9th to 12th cranial nerves above common carotid artery and vagus
- Cervical sympathetic plexus and phrenic nerve posterior to carotid sheath behind the ICA in the prevertebral layer of the deep cervical fascia
- Deep cervical lymph nodes close to vein
- External jugular crosses the sternomastoid belly of the SCM running posteriorly and more superficial to the IJV - later perforating the deep fascia to drain into the subclavian vein
- PLeura rises above the clavicle and is close to the vein at its termination
- Thoracic duct passes inferior and lateral to the confluence of the L IJV and SCV (as it joins on the superior margin of the subclavian vein near the jugular-subclavian junction) and may be injured during LEFT IJV cannulation - the right lymphatic duct can also be injuries during R cannulation but due to its smaller size this is less common
What is the triangle used to ascertain surface anatomy of the IJ vein
- Sedillots Triangle formed from 2 heads of SCM (sternal heat medially, clavicular heat laterally) and clavicle superior border of medial third - enter at the middle of the triangle
What is Sedillots triangle? Describe its makeup
- Sedillots Triangle formed from 2 heads of SCM (sternal heat medially, clavicular heat laterally) and clavicle superior border of medial third - enter at the middle of the triangle
If you use Sedillots triangle for insertion of an IJ describe the surface anatomy for insertion
- Sedillots Triangle formed from 2 heads of SCM (sternal heat medially, clavicular heat laterally) and clavicle superior border of medial third - enter at the middle of the triangle
- Palpate the artery and entry site is lateral to this at approximately C6
- Aim caudally, 30 degree angle to frontal plane parallel to sagital plane and towards ipsilateral nipple
Descibe the USS characteristics of the IJ
Ultrasound - deep to SCM thin walled, non pulsatility and compressible. Either halfway between clavicle and mastoid, or 1/3 of the way up from the clavicle (i.e. slightly lower). Too low and risk of pneumothorax increased but increased separation from carotid, too high and in beard, difficult to dress neatly, carotid closer.
Central approach to the blind IJ insertion technique?
- Central - apex of triangle formed by each muscle belly of the SCM and the clavicle, insert 1cm above apex of head of SCM and clavicle advancing 60cm to skin aiming towards ipsilateral nipple (45 degrees off a coronal plane, needel advaned in a sagital plane) with aspiration of blood at 3cm
Anatomical variations of the IJ vein
Anatomical variations
* Variation in its relationship to the carotid artery - further lateral, or medially overlying the carotid artery anteriorly
* Partial or complete duplication
* Stenosis or occlusion
* Intraluminal membranes, webs or inverted valves
* Congenital aneurysm
* Absent IJV
Describe the path of the external jugular vein
- Crosses SCM sternomastoid belly running posteriorly and more superficial to the IJV later eprforating the deep fascia to drain into the subclavian vein
Origin of the subclavian vein
a direct continuation of the axiliary vein beginning at the lateral border of the first rib as the vein passes deep to the clavicle
Course of the subclavian vein
- The subclavian vein travels medially superficially and superior to the first rib forming a slight groove, posterior to clavicle
- Arches up, medially then down to its termination
- Turns infero-medially entering thoracic inlet into the mediastinum passing anteiro the scalenus anterior
Landmarks on surface anatomy of the subclavian vein
◦ Clavicle
◦ Two muscle bellies of SCM
◦ Suprasternal notch
◦ Deltopectoral groove
◦ Manubrosternal junction
Describe the infraclavicular approach to a subclavian line?
◦ Insert the needle a 1-2cm inferior and lateral to (Deltoid tuberosity of clavicle) junction of medial third of clavicle, 2-3cm inferior to deltopectoral groove aiming towards suprasternal notch (non dominant index finger stays in the supraclavicular notch) and keep neelde parallel to floor
‣ Needle should pass under the junction o the medial 1/3 and lateral 2/3 of the clavicle and directed at index finger/supra sternal notch or just superior
What critical safety aspects to blind insertion of a subclavian line do you need to be aware of? 2 things to never do
- Never angle posteriorly - artery or lung
* Never angle inferior - lung
* Puncture reasonable distance from the clavicle else you’ll never get under it - the more medial you come the more it opposes the pleura
Layers of insertion for a subclavian line
‣ Skin
‣ Subcutaneous fat
‣ Clavicular head of pectoralis major
‣ Clavipectoral fascia enclosing subclavius
‣ Subclavian vein
‣ Further insertion would penetrate scalenus anterior –> subclavian artery/brchial trunk plexus –> pleura
How does the subclavian vein relate to the artery?
◦ Runs together with artery deep to vein throughout course - superior and posterior
◦ Subclavian artery is separated from subclavian vein by scalenus anterior - artery posterior to same
How does the subclavian vein relate to the brachiocephalic plexus
◦ Subclavian artery associated with trunks of brachial plexus posterior to scalenus anterior muscle
◦ Superior and posterior to medial portion of subclavian artery
Subclaivan vs thoracic duct relations
◦ Drains into the subclavian vein ner the junction with the internal jugular vein
Give 4 critical structures you need to be mindful of in surrounding anatomy when isnertion a subclavian line
- Subclavian artery
◦ Runs together with artery deep to vein throughout course - superior and posterior
◦ Subclavian artery is separated from subclavian vein by scalenus anterior - artery posterior to same - Brachiocephalic plexus
◦ Subclavian artery associated with trunks of brachial plexus posterior to scalenus anterior muscle - Thoracic duct
◦ Drains into the subclavian vein ner the junction with the internal jugular vein - Lung - deep and inferior to medial subclavian vein - the dome of the left often extends above the level of the first rib
- Brachial plexus
◦ Superior and posterior to medial portion of subclavian artery
What are the superior relations to the subclavian vein
- superior relations - midpoint of clavicle, superior and posterior subclavian artery, thoracic duct medially, phrenic nerve, lower tunk of brachial pleux laterally
What are the inferior relations to the subclavian vein
Lung and first rib
Anterior relations to the subclavian vein
skin, external jugular, posterior border of clavicle, subclavius muscle
Medial relations to the subclavian vein
- Medial relations - fascia, trachea, brachiocephalic artery, vagal trunk, thoracic duct, oesophagus medial and posterior
Lateral relations to the subclavian vein
Inferior trunk of the brachial plexus
Posterior relations to the subclavian vein
first rib, anterior scalene, phrenic nerve, pleura/apex of lung superiorly, and first intercostal space inferiorly, internal mammary artery
Termination of the subclavian vein occurs where? Left to right differences
- Terminates posterior to the sternoclavicular joint at the medial border of scalenus anterior where it joins the IJV to form the brachiocephalic vein
- LEFT brachiocephalic vein continues inferomedialy crossing the midline before joining the contralateral brachiocephalic vein at the 1st costal cartilage to become the SVC
- Left subclavian - Arcs through the innomninate vein tot he SVC in a gentle curve
- Right subclavian - Sharper angle into the SVC as it joins the IJV
Femoral vein outline - origin, termination, course
Femoral vein is a direct continuation of the popliteal vein and takes a superficial course at the femoral triangle before passing beneath the inguinal ligament to become the external iliac vein
Femoral triangle is otherwise known as?
Scarpa’s triangle
Superior part of the triangle
Base - inguinal ligament from pubic tubercle medially to ASIS laterally
Medial part of femoral triangel
Medial border of adductor LONGUS
Lateral part of femoral triangle
Sartorius
Apex of femoral triangle made up of
Sartorius crosing adductor longus
Floor of femoral triangle
Ilipsoas lateral, pectineus medially
Roof of the femoral triangle
skin —> subcut tissue —> superficial fascia —> deep fascia
Contents of the femoral triangle
NAVEL) nerve, artery, vein,empty space, lymph node
Describe the make up of the femoral triangle
Femoral triangle (Scarpa’s triangle)
* Superior (base of triangle)
◦ Inguinal ligament - running from the pubic tubercle medially to ASIS laterally
* Medial - medial border of adductor Longus
* Lateral - Sartorial muscle
* Apex - sartorius crossing adducotr longus
* Floor - iliopsoas (lateral), pectineus (medial)
* Roof - skin —> subcut tissue —> superficial fascia —> deep fascia
Femoral sheath is what? Created by what fascial layer? What is in it?
Contents of femoral triangle (NAVEL) nerve, artery, vein,empty space, lymph node
* Femoral nerve
* Femoral sheath - conical fascial sheath continuous with transversalis fascia of the abdomen and formed from fusion and invagination of psoas and transversalis fascia
◦ Femoral artery - lateral - it passes under the inguinal ligament at the midpoint between the ASIS and pubic tubercle
◦ Femoral vein - medial
Where does the femoral artery pass relative to the inguinal ligament
Contents of femoral triangle (NAVEL) nerve, artery, vein,empty space, lymph node
* Femoral nerve
* Femoral sheath - conical fascial sheath continuous with transversalis fascia of the abdomen and formed from fusion and invagination of psoas and transversalis fascia
◦ Femoral artery - lateral - it passes under the inguinal ligament at the midpoint between the ASIS and pubic tubercle
◦ Femoral vein - medial
Origin of the femoral vein
- Originates - continuation of the popliteal vein as it passes through the adductor opening
Where does the femoral vein travel in the thigh
- Lies in the intermediate compartment of the femoral sheath
- ◦ In distal adductor canal - vein posterolateral to superficial femoral artery
◦ Proximally in the canal - vein posterior to artery - Terminates at the inguinal ligament as the external iliac vein
Where does the femoral vein terminate
- Lies in the intermediate compartment of the femoral sheath
- Terminates at the inguinal ligament as the external iliac vein
4 major tributaries into the femoral vein
◦ Numerous muscular tributeries
◦ Profunda femoral vein joins the fmeoral vein posteriorly 4-12cm distal to inguinal ligament
◦ Greater saphenous vein enters anteriorly or anteromedially 1-3cm distal to the inguinal ligament draining at the saphenofemoral junction in the femoral triangle
‣ Pierces saphenous hiatus of the deep fascia of the thigh before draining
‣ 99% veinous valve 1-2mm distal to saphenofemoral junction
◦ Lateral and medial circumflex femoral veins
What is the most important vein in reference to the femoral vein when inserting a femoral line
Greater saphenous
◦ Numerous muscular tributeries ◦ Profunda femoral vein joins the fmeoral vein posteriorly 4-12cm distal to inguinal ligament ◦ Greater saphenous vein enters anteriorly or anteromedially 1-3cm distal to the inguinal ligament draining at the saphenofemoral junction in the femoral triangle ‣ Pierces saphenous hiatus of the deep fascia of the thigh before draining ‣ 99% veinous valve 1-2mm distal to saphenofemoral junction ◦ Lateral and medial circumflex femoral veins
Structures that a needle must pass through to gain entry inot the femoral vein
- skin
- subcutaneous tissue
- fascia (encloses the femoral vessels)
- femoral vein
Femoral artery is a continuation of which artery? At which level
originates as a continuation of the external iliac artery at the level of the inguinal ligament
Describe the path of the femoral artery
◦ Enters femoral triangle deep to the midpoint of the inguinal canal - midway point between ASIS and pubic tubercle, lateral to vein
◦ Passes through the triangle exiting at the apex, entering Adductor Canal (Hunter’s Canal)
◦ Exits adductor canal by passing through adductor hiatus in adductor magnus at the level fo the junciton between middle and lower third of the thigh to become popliteal artery
Major branches of the femoral artery (4)
◦ Profunda femoris - artery to tight, from lateral aspect of femoral artery 2-5cm below inguinal ligament
◦ Superficial epigastric
◦ Superficial ilial circumflex
◦ Superficial and deep external pudendal
Medial and lateral relationships of the femoral vein
◦ Medial - femoral vein
◦ Lateral - femoral nerve, lumboinguinal nerve
Superior, posterior and anterior relationships for the femoral vein
◦ Superior - inguinal ligamnet
◦ Posterior - pectineus, psoas, posterior part of femoral sheath
◦ Anterior - skin, superficial fascia lata, lymph nodes, anterior part of femoral sheath
Landmark based femoral insertion
- Inguinal ligament and midpoint of femoral pulse (usually at midpoint of inguinal ligament) and femoral vein 1 - 1.5cm medial to same and 1cm inferior to inguinal ligament
- Ensure veinous puncture inferior to inguinal ligament
What are the boundaries of the antecubital fossa
- Medial
- Lateral
- Superior
- Inferior
- Floor
- Superficial
- Medial – lateral border of pronator teres from the medial epicondyle
- Lateral – medial border of brachioradialis from the lateral supraepicondylar ridge of the humerus
- Superior – an imaginary horizontal line connecting the medial and lateral humeral epicondyles
- Inferior – the apex is directed inferiorly and is formed by the meeting point of the medial and lateral boundaries
- Deep (floor) – brachialis (proximal) and supinator (distal) muscles
- Superficial (roof) – skin, superficial fascia (containing the medial cubital vein, lateral and medial cutaneous nerves of the forearm, deep fascia (reinforced by the bicipital aponeurosis)
Medial antecubital fossa
- Medial – lateral border of pronator teres from the medial epicondyle
- Lateral – medial border of brachioradialis from the lateral supraepicondylar ridge of the humerus
- Superior – an imaginary horizontal line connecting the medial and lateral humeral epicondyles
- Inferior – the apex is directed inferiorly and is formed by the meeting point of the medial and lateral boundaries
- Deep (floor) – brachialis (proximal) and supinator (distal) muscles
- Superficial (roof) – skin, superficial fascia (containing the medial cubital vein, lateral and medial cutaneous nerves of the forearm, deep fascia (reinforced by the bicipital aponeurosis)
Lateral antecubital fossa
- Medial – lateral border of pronator teres from the medial epicondyle
- Lateral – medial border of brachioradialis from the lateral supraepicondylar ridge of the humerus
- Superior – an imaginary horizontal line connecting the medial and lateral humeral epicondyles
- Inferior – the apex is directed inferiorly and is formed by the meeting point of the medial and lateral boundaries
- Deep (floor) – brachialis (proximal) and supinator (distal) muscles
- Superficial (roof) – skin, superficial fascia (containing the medial cubital vein, lateral and medial cutaneous nerves of the forearm, deep fascia (reinforced by the bicipital aponeurosis)
Floor of antecubital fossa
- Medial – lateral border of pronator teres from the medial epicondyle
- Lateral – medial border of brachioradialis from the lateral supraepicondylar ridge of the humerus
- Superior – an imaginary horizontal line connecting the medial and lateral humeral epicondyles
- Inferior – the apex is directed inferiorly and is formed by the meeting point of the medial and lateral boundaries
- Deep (floor) – brachialis (proximal) and supinator (distal) muscles
- Superficial (roof) – skin, superficial fascia (containing the medial cubital vein, lateral and medial cutaneous nerves of the forearm, deep fascia (reinforced by the bicipital aponeurosis)
Superior and inferior margins of antecubital fossa
- Medial – lateral border of pronator teres from the medial epicondyle
- Lateral – medial border of brachioradialis from the lateral supraepicondylar ridge of the humerus
- Superior – an imaginary horizontal line connecting the medial and lateral humeral epicondyles
- Inferior – the apex is directed inferiorly and is formed by the meeting point of the medial and lateral boundaries
- Deep (floor) – brachialis (proximal) and supinator (distal) muscles
- Superficial (roof) – skin, superficial fascia (containing the medial cubital vein, lateral and medial cutaneous nerves of the forearm, deep fascia (reinforced by the bicipital aponeurosis)
If you were going to describe the outline of the antecubital fossa
Pronator teres
Brachioradialis
Line between epicondyles
Contents of the antecubital fossa (4)
- Medial to lateral
◦ Median nerve - leaves between two heads of pronator teres
◦ Brachial artery - bifurcates into radial and ulnar arteries at apex of fossa
◦ Biceps tendon
◦ Radial nerve
Basilic vein originates from
- Originates from dorsal venous network of the hand
How does the basilic vein ascend in the lower arm
- AScends on the medial aspect of the upper limb - joined by the medial cubital vein at the level of the antecubital fossa
How does the basilic vein drain into deep veinous structures
- Perforates the brachial fascia above medial epicondyle
- At the border of the teres major it moves deeper into the arm and combines with the brachial vein from the deep vein out system to form the axillary vein
- The median cubical vein joins the basilic and cephalic veins at the cubital fossa
cephalic vein arises from where?
- Arises from dorsal venous network and ascends the anterolateral aspect of the upper limb passing anteriorly at the elbow
Describe the lower arm course of the cephalic vein
- Arises from dorsal venous network and ascends the anterolateral aspect of the upper limb passing anteriorly at the elbow
How does the cephalic vein progress from the lower arm to its termination
- Arises from dorsal venous network and ascends the anterolateral aspect of the upper limb passing anteriorly at the elbow
- It ascends in the superficial fascia anterolateral to the biceps brachii in a groove between pectoralis major and the deltoid (deltopectoral groove)
- It passes through the anterior wall of the axilla perforating the clavipectoral fascia to drain the first part of the axillary vein often at an oblique angle
What is a brachial vein? Where do you find them? What is it a continuation of?
- Part of the deep venous network
- Brachial vein are venue comitantes of the brachial artery and are situated on either side of the brachial artery underneath the deep fascia
- It is a continuation of the radial and ulnar veins (from the radial and ulna bones) and joins the basilic vein at the inferior border of teres major to form the axillary vein
Radial artery origin?
◦ originates in the cubital fossa as one of two continuations o the brachial artery
Radial artery relations in the arm up to wrist
◦ Radial artery crosses the distal tendon of the biceps brachii
◦ Runs deep to the brachioradilis muscle proximally on the lateral aspect of the forearm - on the medial aspect of the neck of the radius to the styloid process
◦ Distally it is found between the tendons of brachioradialis and flexor carpi radialis muscles
◦ At the wrist its sits proximal and medial to the radial styloid process and lateral tot he flexor carpi radialis tendon; at this point it is covered by skin, subcutaneous tissue and fascia only
◦ At the wrist it wraps lateraly across the floor fo the anatomical snuff box passing dorsally around the scaphoid and trapezium before forming the deep palmar arch and anastomsing withthe ulnar artery
Describe the path of the radial artery from the wrist onwards
◦ Radial artery crosses the distal tendon of the biceps brachii
◦ Runs deep to the brachioradilis muscle proximally on the lateral aspect of the forearm - on the medial aspect of the neck of the radius to the styloid process
◦ Distally it is found between the tendons of brachioradialis and flexor carpi radialis muscles
◦ At the wrist its sits proximal and medial to the radial styloid process and lateral tot he flexor carpi radialis tendon; at this point it is covered by skin, subcutaneous tissue and fascia only
◦ At the wrist it wraps lateraly across the floor fo the anatomical snuff box passing dorsally around the scaphoid and trapezium before forming the deep palmar arch and anastomsing withthe ulnar artery
Termination of the radial artery
◦ In the hand it splits into superficial and deep palmer branches forming anastomosis with distal branches of the ulnar artery supplying the hand - between oblique and transverse heads of adducotr pollicus muscle
Branches of the radial artery
3
◦ Muscular brahnches
◦ Radial recurrent artery - supplies elbow
◦ Palmar carpal and dorsal carpal branches
The radial artery supplies what?
Forearm radial aspect
Extensor and posterior muscle compartments
Hand
Surface anatomy of the radial artery
◦ Distally it is found between the tendons of brachioradialis and flexor carpi radialis muscles
Proximal and medial to the radial styloid process
Brachial artery origin
◦ Brachial artery is a continuation of the axillary artery past the lower border o the teres major muscle
The course of the brachial artery
◦ Medial to humerus with median nerve, basilic vein traversing medial to biceps brachii, and anterior to medial head of triceps –> moves further anterior to humerus as it descends distally
◦ Enters cubital fossa underneath bicipital aponeurosis
◦ In the ante cubital fossa brachial artery is lateral to the medial epicondyle of the humerous and medial the biceps brachii
Termination of the brachial artery
◦ Terminates by bifurcating into radial and ulnar arteries at the inferior border of the antecubital fossa
Tributaries to the brachial artery
◦ Immediately distal to teres major brachial artery gives rise to profunda brachii (deep artery) tarvelling wtih the radial nerve in the radius groove of the humerus supplying posterior structures - terminates in an anastomitic network at the elbow
What eponymous name is given to when brachial artery injury occurs
Volkmans contracture
Variants of the brachial artery
◦ Duplicated for all or part of course in 20%
◦ Superficial course anteriorly rather than posteriorly to median nerve
◦ Bifurcation in proximal arm to superficial radial artery
Dorsalis pedis is a continuation of which artery
- Continuation of the anterior tibial artery distal to the ankle joint
◦ Anterior tibial artery passes between tibia and fibula through gap in interosseus membrane
What 3 arteries enter the foot
Dorsalis pedis
posterior tibial
perineal
Course of the dorsalis pedis artery
◦ Over the distal tibia, then over dosal aspect of tarsal bones inferiorly lateral to extensor hallicus longus in the base of 1st intermetatarsal space
Termination fo the dorsalis pedis artery
◦ Divides into
‣ First dorsal metatarsal artery a terminal branch
‣ Deep plantar artery communicating with plantar blood supply
Surface anatomy of the dorsalis pedis artery
◦ Dorsal surfaec of foot, lateral to extensor hallicus longus tendon, or medially to extensor digitorum longus tendon distal to the dorsal most prominance of the navicular bone
Variant of the dorsalis pedis artery
absent in 1/8 of the population
Posterior tibial artery aries from?
at the lower border of the popliteus the popliteal artery terminates by dividing into the anterior tibial artery and tibioperoneal trunk from which the posterior tibial artery arises
posterior tibial artery course
- Continues inferiorly and medially along the surface of the deep posterior leg muscles (tibialis posterior) - supplying the posterior compartment of the leg
◦ Coursing inferior margin of popliteus muscle up to posterior to medial malleolus - Enters the sole of the foot through the tarsal tunnel deep to the flexor retinaculum entering plantar compartment with the tibial nerve
Termination of the posterior tibial artery
splits into lateral and medial plantar arteries halfway between malleolus and tubercle of calcaenus supplying the plantar side of the foot and the toes via deep plantar arch
Surface anatomy of the posterior tibial artery
- Inferoposteriorly to medial malleolus
Relations of the posterior tibial artery
- Proximally - deep to gastrocneumius and soleus
- Distal more superficial underneath skin
◦ two posterior tibial veins accompny artery
◦ Tibial nerve crosses posterior side of arteries origin and then medial to artery along the course. At flexor retinaculum tibial artery posterior to veins, and anterior to tibial nerve branch (anteroposteriorly = AVN - vein artery nerve)
What is the line corresponding to the body of L4 for a LP
intercristal line
Where is the end of the spinal cord
- End of the spinal cord/Conus medullaris ends at L1/L2 in about 50% of patients or 95% depending on resource
◦ Ranges fromT12 -L3/4 IV disc
◦ Lumbar punctures are therefore performed below L3 to avoid damage to the spinal cord
What is the end of the spinal cord called? What can it range from in terms of anatomical landmarks
- End of the spinal cord/Conus medullaris ends at L1/L2 in about 50% of patients or 95% depending on resource
◦ Ranges fromT12 -L3/4 IV disc
◦ Lumbar punctures are therefore performed below L3 to avoid damage to the spinal cord
Intersection between superior iliac crests and lumbar spine is called?
Tuffiers line
Corresponds to L4 vertebral spinous process
L3/4 interspace can be identified how?
Line joining PSIS
How reliable are our landmark based techniques
50%
LUmbar puncture can be performed in which anatomical spaces
- Lumbar puncture may be performed L2/3 , L3/4, L4/5
Direction of needle passage
Aim 15 degrees cephalic to avoid hitting spinous processes
2 different positions the LP can be perfomed in
sitting
lateral decubitus
Where is the subarachnoid space
Between arachnoid mater and pia mater
Tissues piereced in order for insertion of a LP needle
- skin,
- subcutaneous tissue,
- supraspinal ligament,
- interspinal ligament,
- ligamentum flavum,
- Epidural space (internal vertebral venous plexus)
- dura mater,
- the arachnoid mater into the subarachnoid space.
What are the ligaments piereced by perofrming an LP and their order
- skin,
- subcutaneous tissue,
- supraspinal ligament,
- interspinal ligament,
- ligamentum flavum,
- Epidural space (internal vertebral venous plexus)
- dura mater,
- the arachnoid mater into the subarachnoid space.
How many ‘pops’ should be felt with insertion of an LP needel
- skin,
- subcutaneous tissue,
- supraspinal ligament,
- interspinal ligament,
- ligamentum flavum,
- Epidural space (internal vertebral venous plexus)
- dura mater,
- the arachnoid mater into the subarachnoid space.
Draw a cross sectional description of the spinal cord and nerve roots
Draw a lateral/sagitall cross section of LP insertion
What are the 2 epidural spaces?
posterolateral
anterior
Descrbe the posteriorlateral epidural space
- Posterolateral epidural space extends vertically down the spinal canal and contains arteries, venous plexus, and fat
- Posterolateral epidural space is larger than the anterior epidural space
- Posterolateral epidural space is larger in the sacral region than it is in the cervical region
Describe the anterior epidural space
Anterior epidural space is a virtual space under normal circumstances (due to adherence of dura to bone of vertebral bodies from the foramen magnum down to L1)
Indications for an ICC
PNeumothorax
Trauma and surgery
Pleural effusion
Pleurodesis
Non simple pleural contents
Indications for multiple chest drains
Loculated
CTx surgery
Existing drain poorly positioned but somewhat functional
High flow bronchopleural fistula
Contraindications to an ICC
- Need for emergency sternotomy or thoracotomy
- Pleural adhesions a the site of insertion e.g. post pleurodesis
- Infection at site of insertion
- Coagulopathy
- Emphysematous bullae
- Loculated effusion
- Diaphragmatic hernia
- Hepatic hydrothorax
Complications and risks of an ICC
Pain during insertion
Pulmonary oedema
Lung injury
Cardiac or greater vessel injury
Death
Possible later complications:
Tube may get kinked or blocked
Wound infection may occur
Bleeding from injured intercostal vessels
Chronic pain from injured intercostal nerves
Diagnostic tap requires what to perfom
◦ 21G (green) needle and 50ml syringe
‣ Avoid needle sizes larger than 20g (i.e. <20g) as potentially associated with increased complications
◦ Skin sterilising solution - chlorhex with 70% alcohol, 3 minutes drying time
◦ Sterile gloves
◦ Sterile field
◦ Clean dressing
Draw an underwater seal drain set up
What are the key features to a under water seal drain?
PLeural tube must evacuate contents with minimal resistance
One way valve - underwater seal
Collection chamber
1st bottle of an underwater seal drain does what? How is this faciliated
Collection system
First tube from the chest and collection system must be wide to ensure no resistance
Volume capacity needs to exceed half the patients maximum inspiratory volume otherwise water may enter the chest
2nd bottle of an underwater seal drain does what?
◦ The level of water is only what is required in deep tidal breathing
◦ If only air is being drained this is the only one that is required
◦ When someone has a pneumothorax it proceeds through bottle 1 and bubbles out in bottle 2
◦ In order to escape it needs to overcome the water pressure, e.g. if there is 2cm of water (standard) the air must overcome this pressure
- Volume should exceed 1/2 patients maximum inspriatory volume to prevent indrawing of air during inspiration. Atmospheric vent usually 20cm below water
3rd bottle of an underwater seal drain does what?
- 3rd bottle is used to control any applied suction - the level fo wateris used to set the negtive pressure but suction must only be turned so that bubbles are only just occuring
◦ If furious bubbling the negative pressure in the pleural space will be unpredictiably higher than what is set
◦ If draining fluid without suction this can be dropped
◦ Should bubble continuously if suction applied to appropriate level, if not bubbling then either suction is not being applied or suction is below the required amount for regulation via the system
Where should the drain be positioned relative to the patient
45cm below them to prevent fluid moving back
Important if negative pressure ventilation and higher pressures generated
If you don’t have suction on to an underwater seal drain what is important?
That the suction tubing is not attached otherwise it will be an obstruction to drainage
Why is the triangle of safety where it is?
Aimingto avoid internal mammary artery damage, breast tissue and muscles as only intercostals are penetrated.
Describe the triangle of safety for ICC insertion
◦ Anterior part of triangle - Lateral border of pectoralis major
◦ Posterior/lateral border - Anterior border of latissimus dorsi
◦ Inferior margin - Superior to the 5th intercostal space – be aware the diaphragm (and liver/spleen) may be unexpectedly superior
◦ Superior margin - base of axilla
◦ Anterior to the mid axillary line
How high can the liver be in the chest wall?
- Liver right - at its superior edge can be at the level of the nipple with the lower margin from above the tenth rib on the right to the nipple on the left.
How high can the spleen be on the chest wall?
- Spleen left - relative to the 9th-11th ribs underneath the left part of the diaphragm
Where does the diaphragm arise from?
◦ Lumbar and arcuate ligaments, costal cartilages of ribs 7-10 (directly to ribs 11 and 12), and xiphoid process of the sternum
◦ Right crus - arises from L1-3
◦ Left crus arised from L1-2 and their intervertebral discs
◦ When fully relaxed moves upwards and the upper limits of normal are - 4th intercostal space for right dome, 5th intercostal space fo left dome, xiphisternum centrally, when contracted approximates tendinous origins
Where can the diaphragm sit at its most superior
◦ Lumbar and arcuate ligaments, costal cartilages of ribs 7-10 (directly to ribs 11 and 12), and xiphoid process of the sternum
◦ Right crus - arises from L1-3
◦ Left crus arised from L1-2 and their intervertebral discs
◦ When fully relaxed moves upwards and the upper limits of normal are - 4th intercostal space for right dome, 5th intercostal space fo left dome, xiphisternum centrally, when contracted approximates tendinous origins
Layers of insertion for an ICC
Layers (Superficial –> Deep)
* Skin
* Subcutaneous connective tissue
* Fat
* Ribs and intercostal muscles
◦ Neurovascular bundle (intercostal artery, vein and nerves) lie in intercostal groove on infero-interior surface of the ribs explaining why needly insertion occurs immedaitely superior to a rib
◦ External intercostal muscle
◦ Internal intercostal muscle
◦ Innermost intercostal muscle
* Parietal pleura
* Potential pleural space (pneumothorax)
* Visceral pleura
* Lung
What alternate site cna be inserted into for pneumothroax?
- 2nd intercostal space mid clavicular line
- Neurovascular bundle at lower edge of rib therefore needle over the upper edge of the inferior rib
- Same layers of insertion
- Medial insertion risks mediastinal structures and internal mammary artery, subclavian vessels and subcostal nervous structures superiorly
- Angle of Louis sternomenubrial angle is the join of the 2nd rib –> therefore one space below
How do you determine where the rib space is for a anterior decompression
- 2nd intercostal space mid clavicular line
- Neurovascular bundle at lower edge of rib therefore needle over the upper edge of the inferior rib
- Same layers of insertion
- Medial insertion risks mediastinal structures and internal mammary artery, subclavian vessels and subcostal nervous structures superiorly
- Angle of Louis sternomenubrial angle is the join of the 2nd rib –> therefore one space below
What order are the artery, vein and nerve in for intercostals?
Superior to inferior
Vein
Artery
nerve
Which space is a tracheostomy inserted into?
2nd or 3rd tracheal space
What is the problem with using the 1st tracheal space for tracehostomy
Damage to the cricoid cartilage
What is the problem with going more inferiorly with tracheostomy
- Inferiorly - isthmus of the thyoid and inferior thyroid veins from the 2nd-4th tracheal rings
◦ posterior to strap muscles
Which artery/vein runs along the anterior traceho sometimes
- Branches of the superior thyroid artery run along the superior aspect of the thyroid isthmus anterior to the trachea
- Anterior jugular veins are often connected by a vein that runs superficially across the lower neck
Tracheal course - origin, termination anatomically
- Larynx connects to the superior part of the trachea at C6 into the thorax and terminates at the level of the sternal angle, where it divides into the right and left mainstem bronchi.
- Initially anterior, then moves posteriorly as it descends to move behind the sternal notch
How long is the trachea, what portion is in the neck?
10cm long
5cm in the neck
How many rings are there in the trachea
18-22
Describe the structure of tracheal rings
Incomplete fibrocartilagenous rings
What joins the incomplete tracheal rings together
- The tracheal rings are joined by fibroelastic tissue.
- They are deficient posteriorly where the trachea lies anterior to the oesophagus; the posterior gap is spanned by the involuntary smooth trachealis muscle
Relationships of the laryngx
- Superior - cricoid cartilage
- Lateral - carotid sheaths (common carotid arteries, vagus and internal jugular veins), thyroid lobes, inferior thyroid arteries, posterolaterally either side of the oesophagus are the recurrent laryngeal nerves (posterior to the sheath)
- Inferior to the isthmus of the thyroid gland are the inferior thyroid veins
- Posterior – oesophagus, vertebral column
- Posterior - oesophagus
What is the relavant midline surface anatomy
- Mandible
- Hyoid bone (at level of C3)
- Thyroid cartilage
- Cricothyroid membrane - immediately under the vocal cords is the subglottic space bounded by the cricoid cartilage which can be access through here
◦ The space is bound by 2 semi rigid structures which resist dilation which is why the cricothyroidotomy is not a longer term option as the tubes will only work with narrow lumens which is not ideal for long term use - Cricoid cartilage (at level of C6)
- Thyroid gland
- Tracheal rings
- Sternohyoid muscle just lateral to midline structures, overlies sternothyroid and thyrohyoid muscles
- SCM and clavicle and sternal notce
Layers of dissection for a tracheostomy
- Skin
- Subcutaneous tissue
- Fat
- Muscle - sternothyroid, sternohyoid
- Pretracheal fascia (superficial and deep)
◦ Caution regarding anteiror communicating jugular vein through the space underneath this - Passage through the fibroelastic tissue in between the 1st and 2nd rings (common in perc trache) or 2nd /3rd or 3rd/4th (surgical trache)
- Trachea
Draw a face on view of the inbtubation view and label
Innervation of the larynx internally
- Glossopharyngeal - sensory posterior third of the tongue, calculated and anterior surface of the epiglottis
- Larynx innervated by the vagus - recurrrent laryngeal and superior laryngeal innervation
◦ Posteiror epiglottis is from superior laryngeal
◦ The airway itself below the glottis is the RLN
Which space are you trying to get your laryngoscope into? What ligament are you trying to put tension on?
- Vallecula - space in between he tongue and the epiglottis
- Hypoepiglotic ligament - what you;re trying to lift the epiglottis up by
Sagital diagram of anatomy relevant to intubation
Pathway of insertion of an intubation blade
- Assuming appropriate equipment, positinoing, safety measures and preoxygenation
- Opening of the mouth
- Insertion of the laryngoscopy blade either midline or to the proceduralists right (patients left) and sweeping the tongue to the side
- Blade is advanced down the tongue to the base of the tongue into the valecula with a vision of the epiglottis. If a Miller blade is used it is advanced over the epiglottis
- The larygnoscope is lifted superiorly (moving anatomy anterior relative to standing) to reveal the vocal cords
