No abstract available.
Endocrine System Diseases*

The change of venous capacitance has an influence on venous return to the heart and cardiac output, and causes the alteration of preload, cardiac filling pressure and myocardial wall tension. Venous capacitance is assesed by measuring the mean circulatory filling pressure (MCFP), and MCFP is measured during brief periods of circulatory arrest produced by inflating an indwelling balloon in the right atrium It is important to know the effects of vasodilator and anesthetic drugs on venous capacitance. Therefore, this study was performed to know the effects of nitroglycerin and diltiazem on venous capacitance in rats. Rats were anesthetized with ketamine 125 mg/kg given intraperitoneally and added 10 mg/kg every 30 minutes. Their mean arterial pressure (MAP) was lowered to 60 mmHg by intravenous injection of 0.82+/-0.36 mg/kg nitroglycerin and/or 6.7+/-1.5 mg/kg diltiazem. Hemodynamic parameters such as MAP, heart rate, central venous pressure and MCFP were measured before and after drug-injection. Hemodynamic values measured before drug-injection in two groups were little differences statistically. However, the MCFP of nitroglycerin was significantly decreased (p<0.01) from 7.3+/-0.61 mmHg to 5.4+/-0.58 mmHg after drug-injection, and that of diltiazem was not significantly changed from 7.1+/-0.54 mmHg to 6.9+/-0.63 mmHg. The results suggested that nitroglycerin was predominantly a venous dilator in terms of MCFP but diltiazem had little effect of venodilation.
Anesthetics ; Animals ; Arterial Pressure ; Cardiac Output ; Central Venous Pressure ; Diltiazem* ; Equidae ; Heart ; Heart Atria ; Heart Rate ; Hemodynamics ; Injections, Intravenous ; Ketamine ; Nitroglycerin* ; Rats*

No abstract available.
Germ Cells* ; Neoplasms, Germ Cell and Embryonal*

End-tidal PCO2 measurements are less accurate in neonates, infants, and small children than in adults. These in accuracies may by attributed in part to the dilution of end-tidal gas with fresh gas as a result of placing the sampling catheter between the endotracheal tube and a partial rebreathing circuit. To determine the most accurate catheter position for measurements of end-tidal gas tensions, end-tidal PCO2 was measured continuously from the distal and proximal end of the endotracheal tube and these data were compared with simultaneous arterial PCO2 The results were as follows: 1) In children weigthing above 15 kg ventilated with partial rebreathing circuit, both distal and proximal end-tidal PCO2 values approximated arterial PCO2 (p<0.05). 2) In infants and children weigthing below 15 kg ventilated with Ayre's T-piece breathing circuit(Jackson-Rees modification), only distal end-tidal PCO2 approximated arterial PCO2.
Adult ; Carbon Dioxide* ; Carbon* ; Catheters ; Child* ; Humans ; Infant* ; Infant, Newborn ; Respiration

Recently, several investigators have begun to question the routine use of sodium bicsrbonate in metabolic acidosis, based on a failure to clearly demonstrate the efficacy of alkali therapy, which includes the production of carbon dioxide and variability of the effect on hemodynamic state. We studied the use of sodium bicarbonate in a canine model of hemorrhagic shock to determine its effect on arterial, mixed venous blood gases and hemodynamic states. Nine adult mongrel dogs were anesthetized with pentothal sodium and mechanical ventilation was adjusted to maintained the PaCO2 at 30 to 35mmHg. Ar Swan-Ganz catheter was inserted via a right femoral vein and the right femoral artery was cannulated for continuous pressure monitoring and intermittent blood sampling. 30 minutes after hemorrhagic shock, sodium bicarbonate (1mEq/kg) was administered and 1, 5, 15, 30 and 60 minutes after administration of sodium biearbonate we analyzed the arterial, mixed venous blood gases and measured hemodynamic states. The results were as follows, 1) The arterial carbon dioxide tensions(PaCO2) of 1,5,15,30 and 60 minutes after administration of sodium bicarbonate were 44,42,41,42 and 46mmHg which increased significantly compared to control value, 33mmHg. 2) The mixed venous carbon dioxide tensions(PvCO2) ofr 1, 5, 15, 30 and 60 minutes after administration of sodium bicarbonste were 57, 55, 56, 55 and 55mmHg which also increased significantly compared to control value, 46mmHg. 3) The mean arterial pressures of 1, 5, 15, 30 and 60 minutes after administration of sodium bicarbonate were 61, 60, 64, 68 and 70mmHg which increased significantly compared to control value, 50mmHg, but there were no increasements of cardiac output. It is undesirable to use sodium bicarbonate routinely during hemorrhagic shock because the use of sodium bicarbonate in metabolic acidosis increased arterial and mixed venous carbon dioxide tension and did not show the improvement of hemodynsmic derangement.
Acidosis ; Adult ; Alkalies ; Animals ; Arterial Pressure ; Carbon Dioxide* ; Carbon* ; Cardiac Output ; Catheters ; Dogs ; Femoral Artery ; Femoral Vein ; Gases ; Hemodynamics* ; Humans ; Research Personnel ; Respiration, Artificial ; Shock, Hemorrhagic* ; Sodium Bicarbonate* ; Sodium* ; Thiopental

In 30 ASA class I patients aged 15-30 undergoing peripheral operations, PaO2 and SaO2 were determined while the mixture of nitrous oxide and oxygen was administered at the inspired oxygen concentration of 21%. Anesthesia was maintained with 75% or so nitrous oxide and small dose fentanyl, and ventilation was adjusted to maintain normoventilation with tidal volume increased to 15 ml/kg. PaO2 and SaO2 during anesthesia were increased significantly when compared to those which were measured immediately prior to anesthetic induction, that is to say, no one developed hypoxemia despite administration of the same inspired oxygen concentration as that of room air. These results indicate that, in case rapid emergence from anesthesia is required, balanced anesthesia with high concentration nitrous oxide and small dose fentanyl should be very useful and safe so long as we make good selections of patients and deliver large tidal volumes to them during artificial ventilation.
Anesthesia* ; Anoxia ; Balanced Anesthesia ; Fentanyl ; Humans ; Nitrous Oxide* ; Oxygen* ; Tidal Volume ; Ventilation

The hemodynamic changes of naloxone and nalbuphine following intravenous administra tion of high-dose fentanyl were studied using dogs anesthetized with halothane and ventilated artificially. After 50ug/kg of fentanyl was given to all experimental animals, they were randomly divided into two groups, such as group 1 and group 2. Group 1 and 2 were given 20ug/kg of naloxone and 0.3mg/kg of nalbuphine known as antagonists of fentanyl-induced respiratory depression respectively. Hemodynamic parameters were recorded before, 5 and 30 minutes after fentanyl and 1,10 and 20 minutes after naloxone or nalbuphine. During halothane anesthesia, fentanyl significantly decreased mean arterial pressure, heart rate, cardiac index, rate pressure product, left ventricular stroke work index and right ventricular stroke work index in all dogs(p<0.05). After fentanyl reversal by antagonists, dogs in group 1 promptly developed significant increases above baseline values in mean arterial pressure, heart rate, mean pulmonary arterial pressure, central venous pressure, pulmonary capillary wedge pressure, rate pressure product and left ventricular stroke work index(p<0.05), whereas dogs in group 2 did not show significant hemodynamic changes. These results suggest that the abrupt, untoward and significant hyperdynamic events which accompany narcotic reversal with naloxone can be avoided if nalbuphine instead of naloxone is administered.
Anesthesia* ; Animals ; Arterial Pressure ; Central Venous Pressure ; Dogs* ; Fentanyl* ; Halothane ; Heart Rate ; Hemodynamics* ; Nalbuphine* ; Naloxone* ; Pulmonary Wedge Pressure ; Respiratory Insufficiency ; Stroke

In 30 patients subjected to craniotomy for cerebral aneurysm, the correlation of cerebral blood flow and cerebral metabolism were evaluated by measuring mean arterial pressure (MAP) and cerebral arterio-venous oxygen content differences(AVDO2) during isoflurane and neurolept anesthesia. 15 patients were given 1 MAC isoflurane anesthesia and 15 patients neurolept anesthesia. MAP, AVDO2 and PaCO2 were measured before skin incision, after skin incision, after opening of dura and after closing of dura. The results were as follows: 1) In both groups, significant increases in MAP was observed after skin incision(P<0.05), no significant difference between the two groups was found. 2) In both groups, significant decreases in AVDO2 was observed after skin incision (<0.05), AVDO, values showed insignificant difference. The results indicate that even moderate increases in MAP after skin incision during isoflurane and neurolept anesthesia affect AVDO2 values, suggesting increases in cerebral blood flow. Therefore measures that prevent increase in MAP during incision should be implemented. The study suggests that isoflurane anesthesia is as useful as neurolept anesthesia in terms of AVDO2 to patients undergoing aneurysmal surgery.
Anesthesia* ; Aneurysm* ; Arterial Pressure ; Craniotomy ; Humans ; Intracranial Aneurysm ; Isoflurane* ; Metabolism ; Oxygen* ; Skin

BACKGROUND: P300 component of the long latency auditory evoked potentials (LLAEPs) provides information on conscious and cortical funtion. The P300 wave occures only for stimuli that somehow capture the patients attention. Therefore LLAEPs implys a degree of cognitive processing. We studied sedation scale and P300 wave to determine if LLAEPs could be utilized as electrophysiologic predictors of sedation. METHODS: The P300 component of LLAEPs from vertex was recorded from 10 ASA physical status I and II patients undergoing elective surgery while they listened via headphones to a series of clicks which were interrupted unpredictably by a tone burst (2 KHz) before and after diazepam 0.04 mg/kg and 0.08 mg/kg IV. The patients were asked to concentrate on the clicks and to press a button whenever they detected a 2 KHz tone. And sedation scale also was measured. RESULTS: Amplitude of P300 was decreased and latency of P300 was increased in a dose-dependent manner with IV diazepam. Amplitude was greatest and latency was shortest in awake. And sedation scale also was increased according to increased IV diazepam adminstration. CONCLUSIONS: Both amplitude and latency may be highly related to the sedation scale with progressively increasing dose of diazepam. Therefore we conclude that P300 component of LLAEPs can be utilized as an electrophysiologic predictor of awareness and sedation.
Diazepam* ; Event-Related Potentials, P300* ; Evoked Potentials, Auditory* ; Humans

BACKGROUND: Monitoring of PETCO2 in the patients during regional anesthesia may be no less important than under general anesthesia, but will aid in early detection of potentially catastrophic events. However, the utility and accuracy of capnography in non-intubated patients has received little attention. We examined correlation between PETCO2 measured via nasal cannula and PaCO2 values in the sedated spontaneously breathing patients during spinal anesthesia. METHODS: Thirty adult patients who underwent elective surgery were administered optimal doses of tetracaine and epinephrine mixture in their site of operation, length, weight and age. Thereafter, we sampled expired gas by 175ml/min and administered oxygen by 3L/min using oxygen delivery CO2 sampling nasal cannula. End tidal carbon dioxide tension, heart rate, blood pressure and respiratory rate were measured before and 20 min after 0.02 mg/kg midazolam i.v.. And arterial blood gases were once measured 20 min after 0.02 mg/kg midazolam i.v.. RESULTS: The patients, sedation state was asleep or calm in awake. End tidal carbon dioxide tension was significantly increased after midazolam injection (p<0.01), but another values were not different after midazolam injection. Linear regression analysis of arterial carbon dioxide tension and end tidal carbon dioxide tension after midazolam injection yielded y = 0.77x + 4.82 and r2 = 0.76 (p<0.01). CONCLUSIONS: End tidal carbon dioxide tension using oxygen delivery CO2 sampling nasal cannula in the sedated spontaneously breathing patients with midazolam during spinal anesthesia were significantly related with arterial carbon dioxide tension. Therefore, we conclude that monitoring of PETCO2 via nasal cannula is a reliable means during spinal anesthesia.
Adult ; Anesthesia, Conduction ; Anesthesia, General ; Anesthesia, Spinal* ; Blood Pressure ; Capnography ; Carbon Dioxide ; Catheters* ; Epinephrine ; Gases ; Heart Rate ; Humans ; Linear Models ; Midazolam ; Oxygen ; Respiration* ; Respiratory Rate ; Tetracaine