[Behaviour of near-infrared cerebral oximetry readings during percutaneous carotid angioplasty].
BACKGROUND
Transluminal percutaneous carotid angioplasty and stenting (CAS) carries a risk of cerebral ischemia, hemorrhage, or edema due to relative hyperemia and hemodynamic instability during and after the procedure. Noninvasive monitoring of near-infrared regional cerebral oxygen saturation (SrO2) offers an indirect way to estimate cerebral blood flow.


OBJECTIVE
To evaluate the behaviour of SrO2 during CAS and the usefulness of this variable for continuous monitoring of cerebral blood flow variation and neurological status.


METHODS
Prospective study of 25 patients scheduled for unilateral CAS under monitored anesthesia care. SrO, and other hemodynamic and clinical data were recorded. A change in SrO2 (deltaSrO2) of 15% or more in comparison with the baseline value and lasting more than 30 seconds was considered clinically significant. Neurological complications in the first 24 hours were also registered.


RESULTS
Baseline SrO, ranged from 51% to 75%. With administration of papaverine SrO2 values increased by a mean (SD) of 5.6% (6%) (P<.05 vs baseline). They decreased during angioplasty, -2.5% (5.7%) (P<.05 vs baseline), increased after 5 minutes, and fell again at 30 minutes to a level 3% (6.54%) above baseline. Two patients showed signs of elevated intracranial pressure after the procedures and also had ASrO2 readings exceeding 15%; measures to lower arterial hypertension reduced SrO2 in these patients.


CONCLUSIONS
High interindividual variability of absolute SrO2 values has been confirmed. SrO, fluctuates with maneuvers that change cerebral blood flow in the same way. Changes can precede the onset of other clinical signs.
Rodríguez
L
L
Servicio de Anestesiología, Reanimación y Tratamiento del Dolor, Hospital Clinic i Provincial, Universitat de Barcelona. lrodri@clinic.ub.es
Salvador
L
L
Valero
R
R
Carrero
E
E
Fontanals
J
J
Fàbregas
N
N
D000368:Aged; D000800:Angioplasty, Balloon; D001794:Blood Pressure; D002545:Brain Ischemia / Q000097:blood / Q000188:drug therapy / Q000209:etiology / Q000517:prevention & control; D002343:Carotid Artery, Internal; D016893:Carotid Stenosis / Q000097:blood / Q000628:therapy*; D002560:Cerebrovascular Circulation; D005260:Female; D006339:Heart Rate; D006801:Humans; D006940:Hyperemia / Q000097:blood / Q000209:etiology; D002534:Hypoxia, Brain / Q000097:blood / Q000209:etiology / Q000517:prevention & control*; D019586:Intracranial Hypertension / Q000097:blood / Q000188:drug therapy / Q000209:etiology; D007431:Intraoperative Complications / Q000097:blood / Q000209:etiology; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation / Q000379:methods*; D009422:Nervous System Diseases / Q000453:epidemiology / Q000209:etiology; D010092:Oximetry / Q000295:instrumentation / Q000379:methods*; D010100:Oxygen / Q000097:blood*; D010208:Papaverine / Q000627:therapeutic use; D011183:Postoperative Complications / Q000453:epidemiology; D011446:Prospective Studies; D019265:Spectroscopy, Near-Infrared / Q000295:instrumentation / Q000379:methods*; D014665:Vasodilator Agents / Q000627:therapeutic use
D014665:Vasodilator Agents; D010208:Papaverine; D010100:Oxygen