BACKGROUND: Acutely induced hypoxia causes an increase in the mean arterial pressure, cardiac output and oxygen consumption. However, comparisons of hemodynamic changes and oxygen consumption between subjects with and without anesthesia are rare. The purpose of this study was to examine and compare the hemodynamic changes and oxygen availability after acute apnea between the dogs with and without anesthesia. METHODS: Apnea was induced to 19 healthy mongrel dogs. Group 1 (N=10) constituted dogs with anesthesia and group 2 (N=9) constituted dogs without anesthesia. Hemodynamic data and oxygen levels were rapidly measured with 1 minute intervals. RESULTS: The survival time of group 1 was longer than that of group 2. The mean arterial pressure increased in group 1. Although the cardiac outputs in both groups increased at the same time course in early phase of apnea, the preload values increased more rapidly in group 1. Systemic vascular resistance decreased at 2 and 3 minutes of apnea in group 1 but not in group 2. The oxygen extraction ratio increased significantly at 4 and 5 minutes of apnea in group 2. CONCLUSION: In this study the dogs with anesthesia had a prolonged survival time compared to the dogs without anesthesia. Most hemodynamic values did not differ significantly between the two groups, except for an increased mean arterial pressure and decreased systemic vascular resistance in the dogs with anesthesia. It was suggested that the cause of early death in the dogs without anesthesia was decreased oxygen delivery.
Anesthesia* ; Animals ; Anoxia ; Apnea* ; Arterial Pressure ; Cardiac Output ; Dogs ; Hemodynamics* ; Oxygen Consumption ; Oxygen* ; Vascular Resistance

BACKGROUND: Varying results of hemodynamic and oxygen parameters in response to hypoxia and/or hypercarbia have been reported. In this study, the effects of apnea on the hemodynamic parameters and oxygen availability were evaluated using ten healthy mongrel dogs. METHODS: After full oxygenation, apnea was induced by disconnecting animals from mechanical ventilation. Hemodynamic parameters, oxygen delivery, consumption and extraction ratio were measured at one minute intervals until the cardiac output was undetectable via the thermodilution method. RESULTS: Blood pressure (BP) increased continually following apnea. Cardiac output (CO) increased during the early of apnea (2 and 3 minute) but decreased thereafter. Systemic vascular resistance (SVR) decreased in the early phase of apnea but subsequently declined. The indices of preload increased steadily following apnea. Changes in heart rate (HR) were compared with changes in CO and oxygen delivery, and was found to increase during the early phase of apnea (2~3 minutes) and decrease thereafter. The oxygen extraction ratio did not change significantly and remained steady 6 minutes after apnea but increased and became irregular thereafter. CONCLUSIONS: These data suggest that early reflex responses such as increased BP were primarily due to increased CO, whereas the late increase in BP was due to the increase of SVR. We conclude that BP is not meaningful variables in evaluating critical hypoxic condition such as apnea, and bradycardia might be caused by decreased CO and severe hypoxemia.
Anesthesia* ; Animals ; Anoxia ; Apnea* ; Blood Pressure ; Bradycardia ; Cardiac Output ; Dogs ; Halothane* ; Heart Rate ; Hemodynamics* ; Oxygen* ; Reflex ; Respiration, Artificial ; Thermodilution ; Vascular Resistance

Patient with osseous metastatic prostatic cancer can clinically be detected by bone scanning, which usually is sensitive and qualitative but is not specific and quantitative. For quantitative evaluation of skeletal lesions, we measured bone mineral density (BMD) in whole body, total spine and lumbar spine. All patients also were assessed with bone radiography, radionuclide bone scan, prostate specific antigen (PSA), and prostatic acid phosphatase (PAP). We compared mainly bone scan and BMD in monitoring tumor response between before hormonal treatment and 6 month after hormonal treatment. Fifteen patients with stage D2 prostate cancer and 25 controls were entered in this study. Of 8 patients whose scan showed response in 12 patients with metastatic lumbar spine lesion, they had either 7 responded or 1 unchanged BMD level in the lumbar spine. Of 9 patients whose scan showed response in 15 patients with metastatic total spine lesion, they had either 6 responded or 3 unchanged BMD level in the total spine. The alterations of BMD levels in total spine and lumbar spine closely correlated with the therapeutic responses assessed by the National Prostatic Cancer Project Criteria of bone scintigraphy in patients with prostatic cancer (spine: r=0.04, p<0.05; lumbar: r=0.1, p<0.05). In contrast, BMD changes in whole body (response rate: 20.0%, P<0.05) was less than that in total spin (response rate: 53.3%, P<0.01) and lumbar spine (response rate: 58.3%, P<0.01). In conclusion, when compare BMD to the hot spot region in bone scan, BMD may be helpful to the urologist for the accuracy of the staging and evaluation of the treatment response to androgen deprivation therapy in metastatic prostate cancer.
Acid Phosphatase ; Bone Density ; Densitometry* ; Evaluation Studies as Topic ; Humans ; Prostate-Specific Antigen ; Prostatic Neoplasms* ; Radiography ; Radionuclide Imaging ; Spine

BACKGROUND AND OBJECTIVES: Because tinnitus can be generated from the damaged cochlear hair cells, patients with sudden sensorineural hearing loss frequently complain their tinnitus as an important symptom. We prospectively designed this study to understand the clinical characteristics of tinnitus in patients with sudden sensorineural hearing loss. MATERIALS AND METHOD: Thirty-seven patients with sudden sensorineural hearing loss who performed an audiologic study and questionnare of tinnitus before and immediately after the combination therapy for hearing loss were included. Their clinical and audiologic data were prospectively entered into a comprehensive data base to analyze the clinical characteristics of tinnitus. RESULTS: Most of the patients with sudden sensorineural hearing loss showed abrupt and concomitant onset of tinnitus in the same ear of hearing loss. The characteristics of tinnitus were changed according to the degree of hearing recovery of sudden hearing loss. CONCLUSION: Improvement of tinnitus in the patients with sudden sensorineural hearing loss may be closely related to the degree of hearing recovery. Understanding the characteristics of tinnitus in patients with sudden sensorineural hearing loss might be helpful in counselling them during the treatment period of hearing loss.
Ear ; Hair ; Hearing Loss* ; Hearing Loss, Sensorineural ; Hearing Loss, Sudden* ; Hearing* ; Humans ; Prospective Studies ; Tinnitus*

ATP-sensitive potassium channels (KATP channels) play an important role in insulin secretion from pancreatic beta cells. We have investigated the effect of propofol on KATP channels in cultured single pancreatic beta cells of rats. Channel activity was recorded from membrane patches using the patch-clamp technique. In the inside-out configuration bath-applied propofol inhibited the KATP channel activities in a dose-dependent manner. The half-maximal inhibition dose (ED50) was 48.6+/-8.4 micrometer and the Hill coefficient was 0.73 0.11. Single channel conductance calculated from the slope of the relationship between single channel current and pipette potential (+20~+100 mV) was not significantly altered by propofol (control: 60.0+/-2.7 pS, 0.1 mM propofol: 58.7+/-3.5 pS). However, mean closed time was surely increased. Above results indicate that propofol blocks the KATP channels in the pancreatic beta cells in the range of its blood concentrations during anesthesia, suggesting a possible effect on insulin secretion and blood glucose level.
Anesthesia ; Animals ; Blood Glucose ; Insulin ; Insulin-Secreting Cells ; KATP Channels* ; Membranes ; Patch-Clamp Techniques ; Propofol* ; Rats*