ISSN:0003-3022    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The squared reciprocal of the pre-ejection period (1/PEP2) is an inotropic index which may be measured without catheterization of the left ventricle. Changes in 1/PEP2in response to changes in arterial carbon dioxide tension have been studied. The character of the Paco2/myocardial inotropy response curve was determined in five human subjects and in four dogs. The results clearly showed the dual effects of CO2upon myocardial inotropy in the intact organism. There was evidence to suggest that the initial rise in inotropy as a result of sympathetic stimulation by CO2was age-related in man. In two dogs, the initial rise in inotropy could be prevented by full β-adrenergic blockade. Depression of myocardial inotropy, occurring with high levels of CO2or with lower CO2tensions after β-adrenergic blockade, was a manifestation of the direct depressant effect of CO2upon the myocardium. Halothane produced a symmetrical downward displacement of the Paco2/myocardial response curve in the dog. It is suggested that shifts of the Paco2/myocardial response curve could be used to evaluate drugs which affect the myocardium.

ISSN:0003-3022    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Arterial plasma level-versus-time profiles of mepivacaine were determined for 70 surgical patients undergoing epidural, caudal, intercostalnerve, brachial-plexus, and sciatic/femoral-nerve blocks. A single dose of 500 mg of mepivacaine HCl was used. The conditions studied were route of injection, concentration of drug solution (1 and 2 per cent), and presence or absence of epinephrine, 1:200,000, in the injected solution. Each condition tested resulted in significant changes in maximum plasma levels (Cpmax), time to occurrence of Cpmax(tmax), and areas under plasma level-versus-time curves (∫Cp.dt). The highest plasma concentrations (5–10 µg base/ml) were seen after intercostal-nerve blocks using plain solutions, but addition of epinephrine caused these to become comparable to peak levels after the other blocks (2–5 µg base/ml). For those blocks studied at both concentrations, use of the 2 per cent solution was always associated with the higher Cpmaxand ∫Cp.dt values. Mean values of tmaxusing plain solutions ranged from 9 min (intercostal block) to 30 min (sciatic/femoral) and were increased two-to-threefold by the addition of epinephrine. No systemic toxic reactions were encountered, indicating the safety of the dosage used under the conditions of the study. Addition of epinephrine, 1:200,000, to mepivacaine solutions is recommended for the nerve blocks investigated, especially for intercostal-nerve block.

ISSN:0003-3022    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

In 1,946 obstetrical patients, mepivacaine alone, mepivacaine with epinephrine, and lidocaine with epinephrine were equally effective in relieving the pain of labor. Anesthesia was longer when epinephrine was included, and was also longer for nulliparas than for multiparas with all three anesthetic preparations. The duration of first-stage labor was significantly prolonged by epinephrine. This prolongation averaged 28 minutes for mepivacaine— epinephrine and 39 minutes for lidocaine — epinephrine in nulliparas, and 26 minutes for both combinations in multiparas. Approximately twice as many patients needed oxytocic augmentation of labor with the caudal anesthesia when epinephrine was used.

ISSN:0003-3022    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Nitrous oxide raises the lidocaine seizure threshold 50 per cent above the value measured in awake cats. In 11 awake intact cats breathing air, the median convulsant dose (CD50) of lidocaine was 7.6 mg/kg. In 17 cats ventilated with 70 per cent nitrous oxide the lidocaine CD50was 11.4 mg/kg. One hour after a 0.25 mg/kg im dose of diazepam, the lidocaine CD50was 16.8 mg/kg, whether the inspired gas was air or nitrous oxide. Nitrous oxide supplementation thus reduces the CNS toxicity of local anesthetics, and diazepam reduces it further.

ISSN:0003-3022    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The effects of four analgesics on myocardial contractility were studied in isolated cat papillary muscle preparations. At low doses, both morphine (1–10 µg/ml) and piritramide (0.01–1 µg/ml) produced slight, but non-significant, increases in the extent of shortening, the velocity of shortening, the rate of tension development, cardiac work, and cardiac power. No positive inotropic effects of meperidine and fentanyl were detected. At larger doses all analgesics caused dose-dependent decreases in these measures. Equal contractile depressant doses (measured in terms of 50 per cent inhibition of the velocity of isotonic shortening) were: morphine, 2,000 µg/ml; piritramide, 1,000 µg/ml; meperidine; 100 µg/ml; fentanyl, 10 µg/ml. The results are discussed in relation to equianalgesic potency.

ISSN:0003-3022    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The distribution and excretion of nonvolatile radioactivity in mice after administration of a single dose of14C-halothane by inhalation (10 minutes of anesthesia) and iv are compared. The ratio of the concentration of nonvolatile radioactivity in liver to that in muscle progressively decreased in a period of four days. The liver/ muscle ratio initially was higher after inhalation than after iv administration, but it declined rapidly to a ratio lower than that observed after iv dosing. After inhalation, high levels of nonvolatile radioactivity were present in the nasal mucosa, lung, and thyroid.After a single five-hour period of anesthesia with halothane, all the tissues, but not bile and urine, contained similar concentrations of nonvolatile metabolites. Following numerous fivehour periods of anesthesia, nonvolatile metabolites did not accumulate. In mice, more halothane was converted to nonvolatile metabolites during the 23 hours after recovery than during a one-hour period of anesthesia. The rate of metabolism of halothane to nonvolatile metabolites was highest during anesthesia. Unchanged halothane was found in the bile of the rat and dog, and nonvolatile metabolites of halothane were excreted in the bile of mice and rats.After iv administration of14C-trifluoroacetic acid to mice, the distribution of radioactivity was similar to the distribution of nonvolatile radioactivity after iv administration of halothane.

ISSN:0003-3022    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The distribution of volatile anesthetics in the monkey brain was studied with the technique of low-temperature autoradiography, using14C-labeled halothane, chloroform, diethyl ether, and ethylene. Animals were sacrificed 2, 5, and 20 minutes after administration of the anesthetic. Autoradiographs were prepared from coronal sections of the brain. Results indicate that the early distribution of anesthetics to the gray matter and nuclei is determined primarily by circulatory factors, while the later distribution to the white matter more closely correlates with lipid content, although many exceptions were found. Of particular interest is the high concentration of anesthetic within the reticular formation.

ISSN:0003-3022    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

Twenty-three patients with peripheral-nerve injuries and muscle paralysis were studied to determine the changes in serum potassium following succinylcholine, gallamine,d-tubocurarine, and succinylcholine preceded by 6 mgd-tubocurarine. Potassium increased to 4.00 mEq/1 above control in venous blood of the paralyzed limb, compared with only 0.7 mEq/I in the nonparalyzed limb. Neither gallamine nord-tubocurarine provoked any significant change in serum potassium. d-Tubocurarine prior to succinylcholine reduced the potassium response but did not suppress it. The period of “sensitivity” to succinylcholine in neural injury is more than six months, but more precise limits are not yet defined.

ISSN:0003-3022    

出版商:OVID    

年代:1972

数据来源: OVID

摘要:

The possibility of damage to the ciliated epithelium of the tracheobronchial tree by dry anesthetic gases was investigated in six patients receiving general anesthesia via endotracheal tube for three hours or more. Controls included 12 patients exposed to 60 per cent relative humidity at room temperature (22–26 C) or saturated humidity at 37 C. Ciliated epithelial cells were obtained by bronchial lavage with 5 ml physiologic saline solution immediately after tracheal intubation and at hourly intervals thereafter. Smears made from the suctioned material were fixed at once, stained by the Papanicolaou method, and examined microscopically. Cellular damage was assessed numerically by a point-scoring system.Significant changes were found in smears obtained from patients who had breathed dry gases for more than an hour. After three hours of inhalation of dry anesthetic gases, 39 per cent of cells had damage to the cilia and endplate, 39 per cent had developed cytoplasmic changes, and 48 per cent, nuclear changes, in relation to their condition at the onset of anesthesia. No significant changes were found in smears from patients exposed to gases at 60 per cent relative humidity at room temperature or gases saturated with water vapor at body temperature.

ISSN:0003-3022    

出版商:OVID    

年代:1972

数据来源: OVID