Otoacoustic emission and its application in anesthesia.

OBJECTIVE: An otoacoustic emission (OAE) is a low-level sound emitted by the cochlea. OAEs are able to objectively evaluate the auditory perception and reflect the functional status of the auditory system. With the characteristics of non-invasiveness, high reliability, and easy manipulation, OAEs have gained wide popularity in clinical audiology and anesthesiology. This review aims to summarize the application of OAE in anesthesia. MATERIALS AND METHODS: This study collected data from the databases Web of Science-Clarivate Analytics, PubMed, and Google Scholar in English, covering research in the last 40 years. The keywords were defined as anesthesia, cochlea, OAEs, distortion product otoacoustic emissions, transient evoked otoacoustic emissions, bispectral index, auditory evoked potentials, and depth of anesthesia. Documents that matched defined keywords were selected and reviewed. RESULTS: Research showed that the types and doses of anesthetic drugs impacted OAEs. Ketamine-based anesthesia has a greater effect on OAE sensitivity over time compared to isoflurane. A higher dose of ketamine-xylazine significantly reduced the amplitude of OAEs. According to those characteristics, OAEs could be used as an objective evaluation method for the effect of anesthetics and have great potential to be applied for anesthetic drug dose control during surgery. OAEs also have been used to detect the cochlear function during anesthesia, which may cause irreversible damage to the cochlea. CONCLUSIONS: Studies reported that OAEs have been used in anesthesia. However, the existing studies have mainly focused on the influence of anesthetic types or dosages on OAEs. Considering the characteristics of OAEs, such as a convenient measurement, less susceptibility to interference, and fast detection speed, the application of OAE has a great potential in the anesthesia field.

CT and MRI in target delineation in primary hepatocellular carcinoma.

PURPOSE: To compare the quality of computed tomography (CT) and magnetic resonance imaging (MRI) in target delineation of hepatocellular carcinoma. PATIENTS AND METHODS: Thirty-one patients with hepatocellular carcinoma received CT and MRI (including diffusion-weighted imaging [DWI]) before surgery. The maximal measurement on axial imaging and pathologic examination were extracted for statistical analysis. RESULTS: CT, MRI, DWI-based tumour size correlated well with pathologic sizes, r=0.974, 0.969, 0.964 respectively. But Wilcoxon signed-ranked test showed that differences did exist. CT overestimated the tumour size by 2.9mm compared to pathology (95% CI: -13.2 to 7.4mm). The agreement of MRI-pathology seemed to be worse than CT, with a mean difference of 3.6mm (95% CI: -14.7 to 7.7mm). The worst agreement was in DWI-pathology, with a mean difference of 5mm (95% CI: -17.9 to 7.9mm). But significant difference was found neither between CT and MRI (P=0.477) nor between MRI and DWI (P=0.079). CONCLUSIONS: CT and MRI-based tumour size correlated well with pathologic size, but differences did exist. Most of the lesions were overestimated by CT and MRI. CT and MRI were similar in the guidance of target delineation, and DWI had added little value to MRI. A margin of 10mm around the gross tumour volume to become the clinical target volume is likely not sufficient.

[Hemodynamic study on nitroglycerin compared with Salvia miltiorrhiza].

UNLABELLED: This report investigated the hemodynamic changes of both nitroglycerin and Salvia miltiorrhiza (Co.) concerning pulmonary capillary-wedge (PCW), mean pulmonary artery pressure (MPAP), cardiac output (CO), cardiac index (CI), systemic mean pressure (SMP), and heart rate (HR). In 20 patients with heart diseases of normal cardiac function, nitroglycerin were compared with Salvia miltiorrhiza (Co.) using Swan-Ganz Catheter, which were self-compared. RESULT: (1) Both drugs had the similar vaso-dilating effects, reduced the filling pressure of left ventricle and increased the cardiac output but different in the time of appearance and duration, particularly concerning CO and CI. (2) The effect of Salvia miltiorrhiza (Co.) was markedly superior to the nitroglycerin. The action of former was more persistent and the improvement of cardiac function was better than that of latter.

[Therapeutic effects of nifedipine in pulmonary hypertension secondary to congenital heart disease].

The hemodynamic effects of nifedipine in 15 patients with pulmonary hypertension (PH) secondary to congenital heart disease (CHD) were evaluated. The basal hemodynamic parameters were obtained before medication. The parameters were also obtained 60 minutes and 2 months after taking nifedipine. After treatment, PAPs were decreased 18% and 15% (P less than 0.01), PAPd 21% and 24% (P less than 0.01), PAPm both 19% (P less than 0.01), respectively. TPR were reduced 33% and 30% (P less than 0.01). SAP decreased slightly after 60 minutes. HR, CO and CI remained unchanged. Of the 10 patients suffering from hyperkinetic PH, 8 patients underwent closure of defects after treatment of nifedipine. The above results suggest that nifedipine is effective for patients with PH secondary to CHD. It acted as an antihypertensive agent in patients with CDH associated with hyperkinetic PH before operation.