A 22-year-old male is admitted to your ICU with meningococcal sepsis and a high vasopressor requirement. A right radial arterial line is inserted.
The following morning the bedside nurse reports the right hand is cold and pallid.
What are the potential causes for this finding and outline how you would distinguish between them?
Potential causes
Microcirculatory disturbance secondary to DIC/Vasopressor requirement/worsening septic state.
Suggested by:
Clinical deterioration of patient: escalating vasopressor requirements, worsening acidosis etc. Likely a gradual change not clearly temporally associated with line insertion
Likely to see similar changes in the other limbs
Radial pulse present, arterial waveform present/normal.
Doppler USS, arteriography: - no abnormalities
Traumatic Injury to artery secondary to line insertion
Suggested by:
May be history of difficult insertion, multiple attempts. Other limbs not affected
Likely to manifest relatively quickly after line insertion. Pulse may not be present, arterial waveform abnormal
Imaging may reveal arterial dissection flap, lack of flow distal to line.
Embolic/thrombotic phenomena (including inadvertent drug administration via line)
Rapid onset
History of drug administration through arterial line
ay be other embolic phenomena
May have patchy ischaemic changes over digits
Waveform may be absent or present/normal depending on site of embolus
Imaging may demonstrate thrombus.
Examiners Comments:
Candidates listed the causes, but commonly did not outline how they would distinguish between them. The answer template focussed on history and clinical examination, whereas the candidates’ answers focussed mainly on extensive investigations which would not have been appropriate. This meant that the answers often lacked depth, and therefore did not score well.
One can only add very little to what the college had already
The possibilities are:
Scheer,Perel and Pfeiffer.Complications and risk factors of peripheral arterial catheters used for haemodynamic monitoring in anaesthesia and intensive care medicine. Crit Care. 2002; 6(3): 199–204.