Invasive monitoring

Intra-arterial Catheter

Intra-arterial Catheter

* General:
High benefit - Low risk.
High priority line.
* Site:
Radial artery - 1st preference if palpable.
Brachial artery - if radial not palpable.
Femoral artery - ?+cannulation of femoral vein.
Axillary artery -if others unavailable.
Dorsalis pedis - if access is limited (eg Neurosurgery)
* Benefits:
Blood pressure - beat to beat.
Systolic Pressure Variation - diagnose hypovolaemia or cardiac failure.
Blood samples - gases, Hb, electrolytes, glucose and acid base.
* Risks:
Minimal with good technique.

Central Venous Catheter

Central Venous Catheter

* General:
Intermediate risk benefit.
High priority line for CV drugs.
* Sites:
Internal jugular
External jugular with J wire
Femoral vein
* Benefits:
Right heart filling pressure.
Drug administration, especially CV drugs.
Second volume line.
* Type of Line:
* Multiport, Swan sheath, Arrow catheter. Risks:
At insertion: Int Jug - carotid artery puncture, subclavian - pneumothorax, ext jugular and femoral minimal.
Late: similar for all routes except femoral vein.

Pulmonary Artery Catheter

Pulmonary Artery Catheter

* General:
* High risk/high benefit. Low priority, only consider when patient stable or diagnosis difficult. Sites:
Right or left internal jugular
Basilic or femoral only if neck unsuitable.
* Benefits:
Pressures: CVP, PA, PAWP.
Cardiac output.
Resistances: SVR, PVR.
* Risks:
Risks can be high and life threatening, must have clear indication.

Transoesophageal Echocardiography

Transoesophageal Echocardiography

* General:
Low risk/high benefit
High priority if expertise available.
* Benefits:
Monitoring:myocardial ischaemia, blood volume.
Diagnostic: myocardial disease, valve disease, emboli, pericardial disease, thoracic aortic injury.
* Risks:
Minimal
Misinterpretation, need considerable expertise
* Limitations:
Difficult to maintain diagnostic views
Assessment can be subjective, need comparative views, and objective measurements

Urinary Catheter

Urinary Catheter

* General:
High priority, high benefit - low risk.
* Benefits:
Monitor of urine output.
Aim for at least 0.5ml/kg/hour.
Think of prerenal, renal, and post-renal causes of low urine output.
* Risks:
Trauma, infection.

Temperature

Temperature

* General:
Intermediate priority, high benefit - low risk.
* Benefits:
Aim to maintain normothermia or at least 36 degrees if possible
Hypothermia may be of benefit for neurological injury, but exposes patient to increases in O2 demand, myocardial ischaemia & coagulopathy.
* Risks:
Minor, nasal hemorrhage may be significant.