Key notes on plastic surgery/Adrian M. Richards

POST- OPERATIVE MANAGEMENT 289
Post-operative monitoring
The following techniques can be used to monitor free-tissue transfers in the postoperative
period.
Clinical parameters
Those commonly used include:
• Colour
• Temperature
• Tissue turgor
• Capillary return
• Bleeding on pinprick.
Doppler recordings
• This technique is commonly used.
• It can be used to record arterial or venous flow.
• This form of monitoring may give false-positive readings due to sound
transmission.
Laser Doppler
• The laser Doppler can be used to:
• Record blood flow in a small area
• Scan blood flow over a large area.
• The laser Doppler measures changes in the Doppler shift of light.
• These changes are produced by the movement of macromolecules within vessels.
• The depth of penetration of the laser Doppler is limited to 1.5 mm.
Near infra-red spectroscopy
• This technique is similar to the laser Doppler.
• It utilizes a longer wavelength of light and consequently penetrates deeper.
Temperature measurement
• The temperature of the flap can be measured accurately with a probe.
• A temperature difference greater than 2°C between the flap and the core signifies
possible flap ischaemia.
• Differential thermometry is particularly useful for monitoring digital replants.
Pulse oximetry
• This technique measures the oxygenation of haemoglobin.
• It is useful for monitoring digital replants.
Impedance monitoring
This technique measures the impedance between two electrodes placed on the
flap.
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