Brain Tissue Oxygenation Monitoring And Effect Of Acupuncture On Brain Oxygen Metabolism In Patients During Craniotomy

Objective To investigate the effect of acupuncture on brain tissue oxygen tension (PbtO2) - carbon dioxide tension (PbtCOa) and pH (pHbt) in patients during craniotomy as well as to evaluate the use of Neurotrend-7 as a monitor of brain tissue PO2, PCO2, pH and temperature ( BT) in neurosurgery patients.Methods Twenty-one patients undergoing craniotomy with general anesthesia were monitored continuously by Neurotrend-7 with a multiparameter sensor inserted into the brain which measures tissue PO2, PCO2 pH and temperature. Patients were acupunctured at "Yongquan" and "Lidui" points for 10 minutes. The mean values during 5-min baseline (before acupuncture) of PbtO2 PbtCO2, pHbt - HR and MAP were compared with that of 10 min acupuncture and 5 min post-acupuncture respectively. At the same time, the changes of PbtO2, PbtCO2, pHbt after removal of a traumatic intracranial hematoma were also studied in four patients with traumatic brain injury ( TBI) .Results (1) In 15 patients with brain tumor scheduled for a tumor removal, before acupuncturing, PbtO2, PbtCO2, pHbt of peritumor area (normal brain tissue) were 31 ± 4 inmHg, 47 ± 2 mmHg, 7.16 ± 0.09 respectively. ( 2 ) Removal of intracranial hematomas in four patients with TBI resulted in a significant increase in PbtO2 and pHbt, from 12 ± 7 mmHg and 6.95 ± 0.15 to 23 ± 12 mmHg and 7.07 ± 0.15 respectively (P < 0.05) , decrease in PbtCO2, from 53 ± 8 mmHg to 50 ± 9 mmHg ( P < 0.05 ). ( 3 ) During acupuncture, Pb,O2 , pHbt, HR and MAP in all patients increased from 29 ± 7 mmHg, 7.14±0.10, 80 ± 5 bpm and 79 ± 4 mmHg to 41 ± 6 mmHg, 7.18 ± 0.09 , 96 ± 4 bpm and 87 ± 4 mmHg respectively, PbtCO2 decreased from 48 ± 4 mmHg to 41 ±3 mmHg, 5-min after acupuncture, the Pbto2 decreased from 41 ± 6 mmHg to 35 ± 7 mmHg , PbtCO2 increased from 41 ± 3 mmHg to 44 ± 3 mmHg, pHbt decreased from 7.18 ± 0.09 to 7.16 ± 0.10, HR and MAP returned to baseline, the PbtO2, PbtCO2 and pHbt of 10 min acupuncture and 5min post-acupuncture were significantly different with baseline (P < 0.05 ) .Conclusion (1) Continuous monitoring of PbtO2, PbtCO2, pHbt and BT by Neurotrend-7 is a safe and reliable method, it may give valuable information about the metabolic status of cerebral tissues, allowing direct regional evaluation of pathophysiology of cerebral tissues and early detection of secondary insults, then provide rapid and dependable titration of common therapeutic modalities. ( 2 )The 5-min baseline data of PbtO2, PbtCO2, pHbt measured in the peritumor area (normal brain tissue ) of 15 patients with brain tumor scheduled for the tumor resection are in accord with that of previous studies by other investigators, so it implies that they might be taken as normal range of the parameters. ( 3 ) A clear improvement in O2 supply and cerebral oxygen metabolism could immediately find after removal of a traumatic incranial hematoma in patients with TBI. ( 4 ) The increase of PbtO2 and pHbt and the decrease of PbtCO2 indicate that acupuncture can increase cerebral blood flow and improve substrate delivery to brain tissue and cerebral oxygen metabolism, so it plays an important role in brain protection.