BACKGROUND: Somatosensory evoked potential (SSEP) has been used to help minimize neurologic morbidity during spinal surgery. But, SSEP is affected by various factors, namely technical errors, anesthetics and physiologic aspects (systemic blood pressure, temperature, blood gas tensions). We experienced 40 cases of spinal surgery done with total intravenous anesthesia under SSEP monitoring. We reviewed these cases with the availability of total intravenous anesthesia during SSEP monitoring. METHODS: Forty patients, ASA class I-II, free of neurologic disease and scheduled for elective spinal surgery were randomly selected for the study. All of the operations were performed under general anesthesia employing the method of total intravenous anesthesia with propofol and fentanyl, and monitored by SSEP. We recorded latency and amplitude of SSEP in the pre-induction, post-induction, during-instrument insertion and post-distraction periods. RESULTS: There were no statistical differences in latencies among pre-induction, post-induction, screw insertion and post-distraction period. The amplitude of the post-induction period was statistically higher than pre-induction period (p<0.05), but there were no differences in other periods. None of cases showed abnormal findings (i.e., delay of latency over 10% or decrease of amplitude over 50%). CONCLUSIONS: SSEP monitoring may be helpful in identifying potentially neurologically threatening surgical maneuvers during spinal surgery. To achieve better outcomes, we should consider the effects of various factors on SSEP. Total intravenous anesthesia may be useful method, which has lifter influence on SSEP monitoring.
Anesthesia, General ; Anesthesia, Intravenous* ; Anesthetics ; Blood Pressure ; Evoked Potentials* ; Evoked Potentials, Somatosensory ; Fentanyl ; Humans ; Propofol

BACKGROUND: Many methods are available for the monitoring of spinal cord injury during an operation. During anesthesia, somatosensily evoked potentials (SSEP) may undergo substantial changes in the latencies and amplitudes which may be interpreted as pathological. It is essential for the anesthesiologist to know the potential interactions between anesthetic drugs and neurophysiologic responses during operation. The depressant effect of inhalation agents on the central nervous system exceeds commonly used intravenous anesthetics. Therefore, intravenous anesthesia is preferred to inhalation agents. This study was designed to compare the effects of intravenous anesthetics (propofol and fentanyl) and inhalational anesthetics (enflurane and nitrous oxide) used in the operation room. METHODS: According to the inclusion criteria of ASA I-II, 40 patients who were free of neurologic disease with electric abdominal operations were randomly selected. The baseline of the SSEPs were recorded with stimulation of the posterior tibial nerve at the ankle. After obtaining the baseline (preinduction) of the SSEPs, intravenous anesthetics (propofol 10 mg/kg/h, fentanyl 1 2 microgram/kg) and inhalational anesthetics (end tidal enflurane concentration 1.0 vol %, 50% nitrous oxide in oxygen) were administered. 30 minutes after induction (steady state), additional SSEPs were recorded. Mean arterial pressure, heart rate, temperature and arterial blood carbon dioxide tension were monitored. RESULTS: There were no significant differences in the baseline of SSEPs between the intravenous anesthetics group and the inhalational anesthetics group. There were no significant differences in latencies and amplitudes between the preanesthesia state and the postanesthetia state in the intravenous anesthetics group. But the inhalational anesthetics group revealed prolonged latencies in the postanestesia state as compared with their preanesthesia state. CONCLUSIONS: The above findings suggest that the use of intravenous anesthetics can be beneficial to intraoperative SSEP monitoring for possible damage to the central nervous system during operations.
Anesthesia ; Anesthesia, Intravenous ; Anesthetics* ; Anesthetics, Intravenous ; Ankle ; Arterial Pressure ; Carbon Dioxide ; Central Nervous System ; Enflurane ; Evoked Potentials* ; Fentanyl ; Heart Rate ; Humans ; Inhalation ; Nitrous Oxide ; Spinal Cord Injuries ; Tibial Nerve

Purpose: Atrial fibrillation (AF) patients with low to intermediate risk, defined as non-gender CHA2DS2-VASc score of 0–1, are still at risk of stroke. This study verified the usefulness of ABCD score [age (≥60 years), B-type natriuretic peptide (BNP) or N-terminal pro-BNP (≥300 pg/mL), creatinine clearance (<50 mL/min/1.73 m2 ), and dimension of the left atrium (≥45 mm)] for stroke risk stratification in non-gender CHA2DS2-VASc score 0–1. Materials and Methods: This multi-center cohort study retrospectively analyzed AF patients with non-gender CHA2DS2-VASc score 0–1. The primary endpoint was the incidence of stroke with or without antithrombotic therapy (ATT). An ABCD score was validated. Results: Overall, 2694 patients [56.3±9.5 years; female, 726 (26.9%)] were followed-up for 4.0±2.8 years. The overall stroke rate was 0.84/100 person-years (P-Y), stratified as follows: 0.46/100 P-Y for an ABCD score of 0; 1.02/100 P-Y for an ABCD score ≥1. The ABCD score was superior to non-gender CHA2DS2-VASc score in the stroke risk stratification (C-index=0.618, p=0.015; net reclassification improvement=0.576, p=0.040; integrated differential improvement=0.033, p=0.066). ATT was prescribed in 2353 patients (86.5%), and the stroke rate was significantly lower in patients receiving non-vitamin K antagonist oral anticoagulant (NOAC) therapy and an ABCD score ≥1 than in those without ATT (0.44/100 P–Y vs. 1.55/100 P-Y; hazard ratio=0.26, 95% confidence interval 0.11–0.63, p=0.003). Conclusion The biomarker-based ABCD score demonstrated improved stroke risk stratification in AF patients with non-gender CHA2DS2-VASc score 0–1. Furthermore, NOAC with an ABCD score ≥1 was associated with significantly lower stroke rate in AF patients with non-gender CHA2DS2-VASc score 0–1.