Effect of PaCO2, PETCO2, P(a-ET)CO2 and Regional Cortical Blood Flow on the Prognosis of Craniotomy Patients / 대한마취과학회지

BACKGROUND: Carbon dioxide is a potent cerebral vasodilator. The change of carbon dioxide partial pressure may influence the intracranial pressure and the patients' neurological outcome. There are few reports about the influence of end-tidal CO2 (ETCO2), arterial CO2 (PaCO2) and its pressure difference P(a-ET)CO2 during a craniotomy on the Glasgow coma scale (GCS) score for evaluation of neurological status. In this study, authors tried to discover the influence of PaCO2, PETCO2, and P(a-ET)CO2 on neurological outcome. METHODS: The data of PaCO2 and PETCO2 and P(a-ET)CO2 during a craniotomy was saved. The correlations between each parameter, the GCS score and rCoBF were analyzed. To prevent a direct effect on carbon dioxide tension, blood pressure and body temperature were maintained within a normal range. At the same time, we inserted a probe of the thermal diffusion flowmetry monitor in the subdural space to monitor the regional cortical cerebral blood flow (rCoBF). All the data was saved simultaneously, at the moment of dura closure. RESULTS: There was a fair correlation between the PaCO2 and PETCO2. A low PaCO2 level correlated well with a good GCS score but, not with PETCO2. The mean P(a-ET)CO2 value was 4.4 +/- 3.1 mmHg. The high P(a-ET)CO2 level correlated well with a poor GCS score. High rCoBF correlated well with a good GCS score. However, the changes of PaCO2 and PETCO2 showed no correlations with the rCoBF. CONCLUSIONS: As a result, if we decrease the PaCO2 level by hyperventilation and increase the rCoBF level through proper management during anesthesia, we can improve the patients' neurological outcome.

Comparative Effects of Propofol vs Enflurane on Cardiopulmonary Change during Transthoracic Endoscopic Sympathectomy / 대한마취과학회지

BACKGROUND: Respiratory function and pulmonary gas exchange are affected in thoracoscopic procedures where a pneumothorax is introduced using CO2. Carbon dioxide absorption into the blood during thoracoscopic surgery using intrathoracic carbon dioxide insufflation may lead to respiratory acidosis, increased ventilation requirements, and possible serious cardiovascular compromise. In the present study, the effects of propofol on pulmonary gas exchange were compared with those of enflurane in patients undergoing transthoracic endoscopic sympathectomy (TES) during standard tube ventilation with CO2 insufflation to the surgical side in a prospective randomised manner. METHODS: Sixteen patients with ASA physical status I were divided randomly into enflurane or propofol groups. After induction of anesthesia, patients were ventilated in the same mode in each group. Heart rate and mean arterial pressure were checked and blood gas analyses were performed at 3 time points: 10 min after induction of anesthesia (stage 1), 10 min after CO2 insufflation to the surgical side (stage 2), 10 min after CO2 desufflation from the surgical side (stage 3) under two lung ventilation during TES. RESULTS: Arterial oxygen tension (PaO2) did not differ significantly between enflurane and propofol groups and showed no difference among each stage. PaCO2 and end-tidal CO2 (PetCO2) increased significantly at stage 2 compared to stage 1 and then decreased significantly at stage 3 compared to stage 2 (P < 0.05). There were no significant changes in the mean arterial pressure throughout the procedure with CO2 insufflation in both groups, whereas heart rate was significantly lower in the propofol group than in the enflurane group (P < 0.05) at each stage. CONCLUSIONS: This study demonstrates that pulmonary gas exchange in patients with TES using standard tube ventilation with CO2 insufflation to the surgical side is not affected by choice of anesthesia.

The Effects of Intrathecal Ketamine Isomers on Formalin-Evoked Behavior and Spinal c-fos Expression in Rat / 대한마취과학회지

BACKGROUND: This study was designed to investigate the different analgesic potency and the action mechanism of the intrathecal isomers of ketamine. For these purpose, we evaluated the effect of intrathecal ketamine isomers on the behavioral response and the spinal c-fos expression in the formalin tested rats. METHOD: The subjects were divided into 2 groups(NF group, Fgroup). The NF group was designed for the purpose of the drug itself's effect on the induction of c-fos. Saline(NF/saline group), S(+) ketamine(NF/SK group), R(-) ketamine(NF/RK group) and ketamine(NF/K group) were administered intrathecally to be examined by immunocytochemical method. Same drugs were administered in the F group(F/saline, F/SK, F/RK, F/K) and formalin was injected into right hind paw of the rats after 30 minutes of intrathecal drug administration. The number of flinching was counted at intervals of 5 minutes for 60 minutes. In NF and F group, Fos immunoreactive neurons was counted after 2 hours of formalin injection and intrathecal drug injection respectively. RESULTS: In F/saline group, flinching was developed immediately after formalin injection and revealed biphasic response. The number of flinching in F/SK group, F/RK group, F/K group was significantly smaller than that of F/saline group. The number of flinching of F/SK group by comparison of F/SK vs F/RK was significantly smaller, and that of F/K group by comparison of F/RK vs F/K was significantly smaller. There was no significant difference among NF group on the total number of Fos immunoreactive neurons. In F group, Fos immunoreactive neurons increased significantly in comparison with NF group. The total number of Fos immunoreactive neurons in F/SK group, F/RK group and F/K group were significantly smaller than that of F/saline group. Of F group, the number of Fos immunoreactive neurons of F/SK was the smallest and F/K, F/RK followed increasing order. Attenuation of Fos induction by the ketamine isomers was observed in the whole spinal cord of F/SK group and F/K group but in the superficial and deep laminae of F/RK group. CONCLUSION: This study suggests that intrathecal ketamine isomers have an inhibitory effect on pathologic pain and c-fos expression in the rats and different analgesic effect which is lamina specific.