Knee Aspiration

Contraindications
Joint replacement or prosthesis
Sepsis - local skin sepsis, bacteraemia, osteomyelitis
Cellulitis
Abnormal clotting eg haemophilia or anticoagulation
Immunocompromised or poorly controlled diabetes
Patient refusal.

Complications
Pain
Haemorrhage
Infection
Recurrence - of effusion or symptoms

Procedure
- Expose and position the knee in a relaxed semi-flexed position
- Palpate and identify the patella, patella tendon, and tibial tuberosity
- Mark a point approximately 1 cm medial and inferior to the lower pole of the patella, just medial to the patella tendon overlying the medial joint compartment
- Clean the skin
- Attach a 21G or 23G sterile needle to the syringe and insert the needle directly into the knee joint where previously marked
- Remove 10-20ml of fluid

References
http://bestbets.org/bets/bet.php?id=83
https://lifeinthefastlane.com/procedures/joint-aspiration/
http://learning.bmj.com/learning/modules/flow/JIT.html?execution=e2s1&moduleId=10033838&status=LIVE&action=start&_flowId=JIT&sessionTimeoutInMin=90&locale=en_GB&shouldStartAtQuestionSection=false

Ascites

Abdominal drains are part of our syllabus, but in practice they are normally not done in the ED.

Anatomy
The needle should not insert the rectus abdominus muscle, which is either side of the midline. This can cause epigastric bleeding. Aim for about 15cm lateral to the umbilicus.
Use the Z technique - pierce the skin, pull the skin tight, then aspirate.
The needle pierces:
    Skin
    Subcutaneous fat
    Superficial fascia
    External oblique muscle
    Internal oblique muscle
    Transversalis muscle
    Parietal peritoneum.

Contraindications
Patient refusal or distress
Pregnancy
Abdominal obstruction or distended bowel loops
Cellulitis overlying the puncture site
Severe coagulopathy

Complications
Abdominal Haematoma (1 in 100 patients)
Severe bleeding (haemoperitoneum)
Infection (secondary bacterial peritonitis)
Bowel perforation/organ damage
Persistent site leakage
Hypovolaemia or hypotension
Recurrence (highly likely unless followed up with diuretic therapy)

Causes of Ascites
High SAAG (“transudate”)
cirrhosis, hepatic failure, hepatic venous occlusion, constrictive percarditis, kwashiorkor, cardiac failure, alcoholic hepatitis, liver metastasis

Low SSAG (“exudate”)
malignancy, infection (bacterial, fungal, Tb), pancreatitis, nephrotic syndrome, bowel obstruction or infarction, bile leak

References
http://www.healthline.com/health/z-track-injection#what-are-z-track-injections1
https://lifeinthefastlane.com/ccc/ascitic-fluid/
https://lifeinthefastlane.com/procedures/paracentesis/
http://learning.bmj.com/learning/modules/end/JIT.html?moduleId=10033853&resType=&resTypeId=&locale=en_GB&presourceId=0&site=

Lumbar Puncture

None of the EDs I have worked in recently require us to perform lumbar punctures, but it is one of our competencies - so we should be able to do it...and could be tested on it! 

1.  Palpate the iliac crests and draw an imaginary line between the two. Mark this space (L3/L4) or the one below (L4/5) with a gentle indentation. Ask the patient if it feels like this is in the dead centre. 

Remember the spinal cord ends at L1/2 in adults. 

2. Surgically scrub. 

3. Clean the skin with antiseptic. If you're using a gallipot, remove the chlorhexidine after washing so there is no chance of accidentally injecting it. We should be using 0.5% chlorhexidine - it is better at preventing infection than iodine, and is less neurotoxic than 2%. 

4. Infiltrate local anaesthesia into the space

5. Insert a 20 or 22 gauge spinal needle into the space, with the stylet. 

You will pierce the skin, supraspinous ligament, the interspinous ligament, and then feel a slight resistance as you go through the ligamentum flavum. The needle then goes through the dura with a pop, and through the arachnoid into the sub arachoid space. 

6. Angle the needle slightly caudally, with the bevel parallel to the flanks so it pushes, rather than tears the dura. 

7. Check opening pressure if needed.

8. Collect CSF - get the patient to extend legs to speed up flow if needed. 

9. Replace the stylet before removing the needle to reduce pressure. 

10. Encourage ambulation. 

Complications

Post-LP headache

Infection

Bleeding

Cerebral herniation

Minor neurologic symptoms such as radicular pain or numbness

Late onset of epidermoid tumors of the thecal sac

Back pain

Contraindications

Possible raised intracranial pressure (headache, blurred vision, reduced GCS, vomiting, papilloedema)

Thrombocytopenia or other bleeding diathesis (including ongoing anticoagulant therapy)

Suspected spinal epidural abscess, cellulitis overlying the area

References

http://learning.bmj.com/learning/modules/end/ELU.html?moduleId=10033835

https://lifeinthefastlane.com/procedures/lumbar-puncture/ 

https://www.uptodate.com/contents/lumbar-puncture-technique-indications-contraindications-and-complications-in-adults 

http://rebelem.com/post-lumbar-puncture-headaches/