Emrcs

Question 1

What is a pca?

Answer 1

-Syringe loaded with analgesic (morphine or fentanyl) and IV fluids
-cOnnected to button which pt controls
-Machine is present with parameters that prevent overdose

Patient controlled analgesia consists of a syringe loaded with an analgesic agent such as morphine or fentanyl together with a bag of intravenous fluids. These are linked to a push button that the patient controls. The machine is present with parameters that prevent overdose. The patient presses the button and a preset dose is delivered. A key feature of these devices is that, in general terms, they are only suitable for patients who can understand how to use them. Only the patient themselves should press the button and this is one mechanism by which overdosage is avoided.

Question 2

Why is pain management required after surgery?

Answer 2

-Ambulance–> reduced risk of dvt
-Ventilation–> reduced atelectasis and risk of chest infection
-Reduced sympathetic drive

Adequate analgesia ensures that patients can be sufficiently ambulant which decreases the risks of deep vein thrombosis; allows for adequate ventilation thereby reducing atelectasis and subsequent chest infections. In addition, there is also a reduction in sympathetic drive.

Question 3

How to manage the pain of the pt going for surgery

Answer 3

Simple procedures:
-infiltration of LA into wound and simple analgesia

More complex procedures-surgical factors include:
-limiting length if incision
-careful tissue handling
-laparoscopic over open techniques

Stronger pain relief options:
-spinal block
-epidural
-rectus sheath catheter
-pca

In general terms, a multi modal strategy is adopted. For simple minor procedures, infiltration of the wound with long acting local anaesthetic accompanied by regular combination oral analgesia is sufficient (e.g. paracetamol and ibuprofen). For more extensive procedures, there are surgical factors that can also impact on recovery, limiting incision length, careful tissue handing and the use of laparoscopic over open approaches; can all help to reduce the incidence of post operative pain.

Stronger analgesic options include:
Patient controlled analgesia
Spinal blocks
Epidurals

Question 4

What are the complications of a spinal?

Answer 4

-hypotension due to sympathetic nervous system blockade
-post dural puncture headache
-spinal canal haematoma

This is a form of regional anaesthesia in which a fine needle is passed into the sub arachnoid space and a dose of local anaesthetic is injected. Spinal anaesthetics have a faster onset of action than epidurals and tend to only be used for a single dose. Motor blockade is more common with spinal anaesthetics and they can only be administered below the level of L2 to avoid cord injury. Complications include the development of hypotension due to sympathetic nervous system blockade, post dural puncture headache, spinal canal haematoma.

Question 5

epidural complications

Answer 5

-Infection and abscess formation
-Haemodynamic instability
-Incomplete block

This is a technique whereby a needle and usually an indwelling catheter are inserted into the epidural space. Because this does not carry the same risks of impinging on the cord, epidurals can be given at different levels to spinal injections. Motor blockade is usually less than with spinal injection. However, the onset of action is slower and some patients can have incomplete blocks. Haemodynamic instability can occur though its generally less than with spinal injection. Repeated dosing can be given as there is usually an indwelling catheter. The risks of infection and abscess formation are present with epidurals so an aseptic technique during insertion is crucial.

Question 6

What is neurogenic shock?

Answer 6

-Distributative shock
-Loss of systemic vascular resistance
-Damage to sympathetic outflow tract following spinal cord injury

This is a form of distributive shock characterised by hypotension where the underlying cause is a loss of systemic vascular resistance owing to a damage to the sympathetic outflow tract following spinal cord injury.

Question 7

At what level(s) would you consider spinal cord injury to be compatible with the development of neurogenic shock?

Answer 7

Injury to levels T6 and above. Injuries significantly below this level seldom produce sufficient sympathetic disruption to cause significant neurogenic shock and an alternative cause for shock should be carefully considered in such circumstances.

Question 8

Describe neurogenic shock

Answer 8

Spinal cord injury may produce hypotension due to loss of peripheral sympathetic vasopressor tone. Because of the possibility that hypovolaemia may co-exist with neurogenic shock (since spinal transection is seldom isolated), this should be addressed initially with appropriate fluid resuscitation. Neurogenic shock may mask the normal physiological response to hypovolaemia. An associated head injury is present in up to 25% of spinal cord injury patients.

Neurogenic shock classically occurs in spinal injuries above the level of T6 and is due to loss of sympathetic autonomic outflow below this level. The main presenting feature of all cases of distributive shock occurs secondary to loss of SVR. The CVP is usually unaffected unless there is co-existing hypovolaemia. Cardiac output remains the same or may even be elevated. Where the injury is above the level of T6 there is hypotension and when the level is above T1 there is an associated bradycardia because there is then the added component of unopposed vagal tone.

Management is with intravenous fluid resuscitation to expand the circulating volume and administration of supplementary oxygen. The use of nor adrenaline and / or atropine may also be necessary.

Question 9

Surgical factors that can influence pain after surgery

Answer 9

-limiting incision length
-careful tissue handing
-use of laparoscopic over open approaches;