The use of controlled hyperventilation during neurosurgical procedures prevents the deleterious effects of hypercarbia on the cerebral blood flow and intracranial pressure. hyperventilation with hypocarbia produces cerebral vasoconstriction, reduced cerebral blood flow and a reduction in brain size in the majority of patients with increased intracranial pressure. But since excessive cerebral vasoconstriction might induce cerebral ischemia, there has been much discussion concerning the optimal level of hypocarbia. Several studies have shown biochemical evidence of a change in cerebral glucose utilization to anaerobic metabolism during hypocarbia. In our investigation, the effect of hyperventilation on 10 neurosurgical patients was evaluated by blood gas analysis and the estimation of lackate and pyruvate in arterial blood and the cerebrospinal fluid. The results were as follows: 1) PaCO2 decreased from a prearesthetic value of 38+/-2.2 mmHg to 22+/-2.1mmHg 1 hour postinduction and 24+/-2.2mmHg at 2 hours due to hyperventilation. pH was 7.58+/-0.047 1 hour postinduction and 7.56+/-0.018 at 2 hours. PaO2 was 251+/-33.0mmHg 1 hour postinduction 1 hour and 215+/-20.9mmHg at 2 hours under a 50% inspired oxygen concentration(FiO2=0.5). 2) The arterial blood lactate value increased statistically significantly from a preanesthetic value of 9.3+/-1.5mg% to 11.8+/-1.47mg% 1 hour postinduction(p<0.01) to 12.5+/-1.53mg% at 2 hours(p<0.005). However all values were within the normal range(4.7+/-15.1mg%), and the lacte/pyruvate ratio did not change. 3) In the cerebrospinal fluid, pH was 7.45+/-0.057, PCO2 was 34+/-3.5mmHg and PO2 was 91+/-6.7mmHg following hyperventilation for 1 hour. The lactate value of the cerebrospinal fluid was 19.2+/-3.14mg%(normal range: 11.0~27.0mg%) and the lactate/pyruvate ration was 14.5+/-2.39. 4) No evidence of an excessive increase in CSF lactate was seen in any case. The above findings suggest that maintenance of an adequate oxygen concentration and a carbon dioxide value over 20mmHg would prevent cerebral ischemia following hypocarbia due to hyperventilation.
Anesthesia* ; Blood Gas Analysis ; Brain ; Brain Ischemia ; Carbon Dioxide ; Cerebrospinal Fluid* ; Glucose ; Humans ; Hydrogen-Ion Concentration ; Hyperventilation* ; Intracranial Pressure ; Lactic Acid ; Metabolism ; Neurosurgical Procedures ; Oxygen ; Pyruvic Acid ; Vasoconstriction

OBJECTIVE: The purpose of this study was to evaluate the efficacy and toxicity of concurrent chemor- adiotherapy (CCRT) in loco-regionally advanced cervical cancer patients. METHODS: The medical records of 24 patients were retrospectively reviewed who underwent CCRT' and 62 patients who had underwent radiation therapy alone at the Department of Obstetrics and Gynecology, Ajou University Hospital from September, 1994 to August 2000 for loco-regionally advanced cervical cancer (stage IIb-IVa and Ib-IIa with bulky tumor mass or pelvic lymph node involvement detected by magnetic resonance imaging). Radiotherapy was performed for 7 weeks during which the patients underwent radiotherapy and chemotherapy concomitantly. Chemotherapeutic regimen consisted of cisplatin (75 mg/m2 on day 1, 4) and 5-FU (1000 mg/m2 on day 2-5, 30-33). The toxicity was assessed according to the GOG toxicity criteria. RESULTS: In the CCRT group, 2 of 18 patients (11.1%) had recurrent disease. Of the 22 patients who were followed up, the overall survival rate was 83.3%, and the relapse-free survival rate was 89.9%. In the radiotherapy alone group, 19 of 61 patients (32.3%) had recurrent disease. Of the 62 patients who were followed up, the overall survival rate was 75.4% and the relapsed-free survival rate was 67.7%. Relative risk reduction rate of the death rate in the CCRT group was 66% (RR 0.34), and 32% (RR 0.68) in the recurrence rate. Acute toxicities in the CCRT group were enteritis grade 3:3 (12.5%), leukopenia grade 3:2 (8.3%), anemia grade 3:1 (4.1%) and grade 4:2 (8.3%). The acute toxicities in the radiation therapy alone group were enteritis grade 3:7 (11.3%), rectal bleeding grade 3:1 (1%). Increased acute toxicities developed in the CCRT group. CONCLUSION: This study shows improved overall survival rates and relapse-free survival rates but some increase in acute toxicity. It is suggested that CCRT be the standard treatment of loco-regionally advanced cervical cancer. Due to small size sample and short duration of follow up, further study of a large group of patients and the long term survival rate are necessary.
Anemia ; Chemoradiotherapy* ; Cisplatin ; Drug Therapy ; Enteritis ; Fluorouracil ; Follow-Up Studies ; Gynecology ; Hemorrhage ; Humans ; Leukopenia ; Lymph Nodes ; Medical Records ; Mortality ; Obstetrics ; Radiotherapy ; Recurrence ; Retrospective Studies ; Risk Reduction Behavior ; Survival Rate ; Uterine Cervical Neoplasms*