Injections and anasthesia Flashcards
Where does the spinal cord terminate in the adult?
L1/L2 vertebrae
Where does the spinal cord terminate in children?
L2/L3 vertebrae
Where does the subarachnoid space (filled with CSF) terminate?
S2 vertebrae
What does the supracristal plane mark?
The higest point of the iliac crest
L4 spinous process
Describe how a lumbar spinal puncture is performed
Lumbar punctures are performed to obtain a sample of CSF.
The patient is positioned leaning forward or lying onthe side with back flexed. This spreads teh laminae and spinous processes apart.
The needs is inserted into the subarachnoid space at the midline between the spinous process of L3/L4 vertebrae in an anterosuperior direction (15 degree angle)
What region of the spine is anaesthesia administered to the CSF?
Between L3/L4 to L5/S1
Needle is passed into the subarachnoid space where teh anesthetic is administered
Where would you administer caudal anasethesia?
Sacral hiatus
Blocks S2-S5
What is the effect of epidural anaesthesia?
An anesthetic agent can be injected into the epidural space by inserting a sterile needly into the spine between the spinous processes of L3/L4.
The anesthetic has a direct effect on the spinal nerve roots of the cauda equina after they exit from the dural sac. The patient loses sensation inferior to the level of the block.
The angle at which the needle is inserted depends on the region of the spine injected. e.g. in thoracic region angle of needle increases towards the head.
Describe the two methods used to deliver IM injections in the gluteal region
- Vertical line from the highest point of the iliac crest. Horizontal line midway between the ighest point of the iliac crest and the ischial tuberosity. Inject in the upper lateral quadrant
- Vertical line from the highest point of the iliac crest. Horizontal line from the PSIS to the greater trochanter. Inject in the upper lateral quadrant
Phlebotomy
Sampling of blood from superficial veins
Normally perfoemd at cubital fossa of upper limb. Can access cephalic (safest), basilic or median cubital vein
Use of a cannula in taking blood
Put in place where repeat blood samples are required
Used for short term venous access
IV fluid infusion (fluid, blood drugs)
Repeated drug administration
Measuring central venous pressure
Borders of the cunital fossa
Epicondylar line,
pronator teres
brachoradialis
Stae 4 complicatins of superficial venous cannulation
Venous inflammation
Thrombosis
Thrombophlebitis (clot and inflammation)
Sepsis
Tissue infusion
What are the common locations for superficial vein cannulation?
Cubital fossa
Dorsum of the hand
Anatomical snuffbox
Medial ankle (with a cutdown)
What are theborders of tha anatomical snuffbox?
Superior: Extensor pollicis longus
Inferior: Extensor pollicis brevis and
Abductor pollicis longus
Describe the course of the great saphenous and small saphenous vein
Great saphenous vein: Passes from the dosrum of the foot anterior to the medial malleolus up the medial aspect of the lower limb. Runs along the medial tibial border with the saphenous cutaneous nerve, posterior to the patella and up the medial thigh to the saphenous opening at the pubic tubercle where it drains into the femoral vein.
Small saphenous vein: Passes from the lateral part of the foot, posterior to the lateral malleolus into the posterior leg. It ascends in the midline along the sural cutaneous nerve then enters teh popliteal fossa to drain into the popliteal vein.
Where would you cannulate a child?
Cubital fossa
Dorsum of the hand
External jugular vain
Scalp
Interosseous of anterior tibia
Venous cutdown (saphenous vein)
Describe the ligation method of cannulating the saphenous vein
Blunt dissection of saphenous vein from saphenous nerve for 2cm.
Ligate teh distal mobilised vein
Pass a tie around the proximal part of the vein
Make a small incision in the vein
Introduce a cannula and tie with the proximal suture
Attach IV line to cannula
When would arterial cannulation be required?
To asess acid-base status
Measuremen of arterial blood gases
Assessment of respiratory/cardiac/renal failure
Drug overdose
DKA
Lactic acidosis
Cardiac catheterisation
State 4 complications of arterial cannulation
Haematoma
Arterial spasm leading to ischemia
Retrograde embolism
Traumatic aneurysn
Infection/sepsis
Name three arteries commonly accessed for cannulation
Brachail artery
Radial artery
Femoral artery
What are the borders of the femoral triangle?
Inguinal ligament
Sartorius
Adductor longus
Describe the standard method for cannulating the saphenous vein
Blunt dissection of the saphenous nerve from the saphenous vein
Puncture the vein with an IV catheter
Introduce the cannula and withdraw the needle
Confirm free flow of blood
Attach IV line to cannula
How do you access the saphenous vein for cannulation?
Identify the medial malleolus
Palpate the great saphenous vein (2cm anterior)
Measure 1cm anterior and superior to medial malleolus
Make an inscision 2.5cm from the anterior point to the posterior border of the tibia
