|Microsurgery: Transplantation and Replantation by Harry J. Buncke, MD, et al.|
| Transcutaneous oxygen monitoring electrodes measure tissue oxygen tension after producing local hyperemia with a heating coil. Decreased oxygen tension occurs with ischemia. The monitor has been used with success experimentally36-38 and clinically.5,22,38 Skin injury from the heating coil, as well as variable readings with edema and eschar, are reported disadvantages.
AN APPROACH TO POSTOPERATIVE MONITORING
Physical examination, quantitative fluorimetry, and surface Doppler examinations are the mainstays of our postoperative monitoring.
All visible tissue transplants and replanted parts are regularly inspected by nurses for turgor and quality of capillary fill. Any abnormalities noted during nursing examinations are reported promptly to a physician.
Quantitative fluorimetry is used to monitor replanted parts and tissue transfers with cutaneous components or skin islands. The readings are obtained by nurses. The fluorimeter is initially calibrated to a standard light source, and baseline skin readings are obtained from the monitored tissue and a control area. Repeated readings are obtained 10 and 60 minutes after injection of 0.5 to 1.0 mg/kg of fluoroscein intravenously. Absence of a rise in fluorescence at 10 minutes indicates arterial occlusion. Absence of a fall in fluorescence at 60 minutes indicates venous obstruction. Determinations are made every 2 hours in the early postoperative period. Fluorimetry often detects vascular complications before physical examination.
Detection of pulses by regular Doppler examination is our method of monitoring buried flaps or flaps without cutaneous components. The site of examination is carefully determined intraoperatively to correspond to a pedicle or axial vessel. The site is frequently marked by a suture or marking pencil and the dressing is tailored to expose the site. This method of Doppler application has minimized misleading signals obtained from adjacent or underlying vessels.
These monitoring strategies have proved reliable and easily performed in our clinical setting. Our personal experience with pulse oximetry includes experimental data showing that this instrument does not promptly detect subtotal venous occlusion, and that the probe adhesion and sensitivity can be compromised by bloody surfaces. We have not, therefore, adopted pulse oximetry as a routine postoperative monitoring device.
We have had minimal experience with other available monitoring devices, but in the future will compare new ones to our present strategies for advantages in simplicity and reliability.
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