Anesthesia of marmots with sodium pentobarbital, ketamine hydrochloride, and a combination of droperidol and fentanyl

Three different anesthetics were tried on wild marmots to immobilize them sufficiently for intra-oral physiologic measurements and dental examination. Essentially the same procedure was performed or attempted on 15 animals. The droperidol (20 mg/ml) and fentanyl (0.4 mg/ml) combination gave better results than sodium pentobarbital or ketamine hydrochloride and was therefore used in most instances. We concluded that the dose rate should be adjusted to the nutritional state of the animal as well as to the absolute weight.

Deep anesthesia in the rat with the combined action of droperidol-fentanyl and pentobarbital

A combination of droperidol-fentanyl and pentobarbital, administered ip, was used to obtain a state of deep anesthesia in rats for purposes of radionuclide imaging, as well as for various surgical procedures. Two or more hr of anesthesia were easily obtained. A 7.2% mortality rate (3/42) was experienced in a 3-mo study in which 5.2 procedures per rat were performed. The duration of anesthesia was found to vary both with sex and with the time of day at which the drugs were administered.

Cardiopulmonary effects of fentanyl-droperidol, nitrous oxide, and atropine sulfate in dogs

The cardiopulmonary effects of droperidol-fentanyl, nitrous oxide, and atropine were evaluated in 12 adult male Beagle dogs. All dogs were surgically instrumented with a cardiac output thermistor and arterial and venous catheters and were prepared with a chronic tracheostomy. Each dog was used as its own control, and data obtained when dogs were nonanesthetized and nonmedicated were compared with data recorded after the test drugs were administered. The dogs were randomly allotted to 3 groups of 4 dogs each. Group I dogs were given droperidol-fentanyl alone intravenously (IV); group II dogs were given droperidol-fentanyl IV with 67% nitrous oxide; and group III dogs were given atropine sulfate intramuscularly followed by droperidol-fentanyl IV with 67% nitrous oxide. Minute volume was decreased in the 3 groups of dogs for 3 to 5 minutes after droperidol-fentanyl was injected. This resulted in respiratory and metabolic acidosis in all dogs, as indicated by increased arterial carbon dioxide tension, decreased pH, and increased base deficit. In addition, droperidol-fentanyl given alone caused a decrease in systolic pressure and a slight decrease in heart rate. Group 1 dogs were sensitive to auditory stimulation. Cardiovascular changes were not seen when nitrous oxide was added; however, analgesia and muscle relaxation were improved. Premedication with atropine sulfate resulted in increased cardiac output, heart rate, and diastolic pressure, and subsequent administration of droperidol-fentanyl with nitrous oxide caused a transient increase in mean arterial and systolic pressure. This last anesthetic regimen, along with assisted or controlled respiration, seems to provide an excellent anesthetic state with minimal cardiopulmonary depression.

Comparison between fentanyl and morphine for use in analgesic anesthesia during open heart surgery

One hundred unselected adult cardiac patients operated on with extracorporeal circulation (ECC) underwent analgesic anesthesia. In half of the cases, the analgesic used was morphine and for the others fentanyl. Anesthesia was completed with flunitrazepam, pancuronium, nitrous oxyde and a neuroleptic if necessary. Operative, postoperative and recuperation periods were very satisfactory and very the same in both series. Due to its small administrated dosage (average 1.22 mg/kg) the secondary effects of morphine remained discrete. Although its long action suits well the concerned type of surgery there seems to be no reason to prefer it to fentanyl.

Effects of fentanyl and droperidol on canine left ventricular performance

The effects of fentanyl and droperidol on left ventricular performance were evaluated in the neurally intact dog right-heart-bypass preparation under conditions of constant cardiac output, arterial pressure, and heart rate. Fentanyl, .01 and .02 mg/kg body weight, and droperidol, 0.5 mg/kg, did not affect left ventricular performance. However 1.0 mg/kg droperidol caused a significant (P less than .05) increase in left ventricular end-diastolic pressure and a small decrease in maximum left ventricular dP/dt (.05 less than P less than .10). No significant change in myocardial oxygen consumption was observed. This study indicates that large doses of droperidol may depress left ventricular performance and may account for a portion of the hypotension observed after its administration in man. (Key words: Anesthetics, intravenous, fentanyl; Anesthetics; intravenous, droperidol; Heart, function, fentanyl; Heart, function, droperidol.).

Patient refusal of surgery following Innovar premedication

Of 1438 patients premedicated with Innovar, 10 refused to undergo surgery. During the same period, there were no refusals by 2107 patients not premedicated with Innovar. This apparent difference suggests that a prospective study of Innovar and droperidol be made to determine whether there are changes in patient attitude that lead to refusal of surgery.

Hemodynamic and ventilatory responses to fentanyl, fentanyl-droperidol, and nitrous oxide in patients with acquired valvular heart disease

Fentanyl (10 mug/kh) or fentanyl (10 mug/kg) plus droperidol (100 mug/kg) administered intravenously during 20 minutes to adult patients with acquired valvular heart disease produced minimal circulatory changes. The trend during drug infusion was for mean arterial pressure and systemic vascular resistance to decrease, and for cardiac index and stroke volume index to increase without change in heart rate. Central venous pressure increased during drug infusion (P less than 0.05) but decreased to awake levels following controlled ventilation and skeletal-muscle paralysis, probably reflecting thoracoabdominal-muscle rigidity rather than a circulatory response. Hypoventilation during drug infusion necessitated assisted or controlled ventilation, with or without skeletal muscle paralysis, in 14 of 16 patients. Addition of 60 per cent nitrous oxide following fentanyl or fentanyl-droperidol infusion significantly decreased mean arterial pressure, heart rate, and cardiac index. All circulatory changes were similar in direction and extent to those previously found during morphine-nitrous oxide anesthesia. (Key words: Anesthetics, intravenous, fentanyl; Anesthetics, gases, nitrous oxide; Heart, effect of fentanyl, dorperidol, and nitrous oxide.).

Cardiovascular effects of minimal analgesic quantities of Innovar, fentanyl, and droperidol in man

In volunteer human subjects not undergoing surgical operations and breathing spontaneously, the cardiovascular effects of Innovar and of its components, fentanyl and droperidol, were determined when the drugs were administered in minimal amounts necessary to reach an analgesic endpoint. This amount was fentanyl 5 mcg./kg. body weight combined with droperidol 0.22 mg./kg. Innovar, or its components when administered separately, produced minimal cardiovascular changes of consequence during the time of maximum analgesia (about 15 minutes). With the passage of time after administration of a single dose of Innovar, there were some changes in cardiac output, heart rate, and stroke volume, probably representing normal changes of sedated sleep. None of the changes, acute or delayed, was clinically significant. Analgesia could be achieved only when fentanyl was combined with droperidol; and although a certain amount of respiratory depression resulted from the combined drugs, the authors concluded that the observed cardiovascular changes probably represented primary drug effects.

The effect of artifical ventilation and dehydrobenzperidol on the development of early changes in the respiratory system in dogs with Mendelson's syndrome

The experiments were carried out to observe certain functional changes in the respiratory system which develop in the early stage of aspiration pneumonia and to study the possibility of influencing these changes by application of artificial ventilation (IPPB) and/or administration of dehydrobenzperidol. The experiments were carried out on 32 mongrel dogs divided into 4 groups. Experimental Mendelson's syndrome was produced by instilling, during anaesthesia, hydrochloric acid solution of pH 1.5 in a dose of 4 ml/kg into the tracheobronchial tree. Immediately after anaesthesia and then 10 times at intervals of one hour after HCl instillation the following determinations were done: mean blood pressure, CVP, haematocrit, PO2 and PCO2 in arterial and mixed venous blood, and minute artifical ventilation. The veno-arterial blood shunt in the lungs, alveolo-arterial difference of oxygen partial pressure and the effective compliance were also determined. The chemical damage to the lungs by acid caused condensation of blood and a fall in CVP. These changes were due to fluid escape from the vessels especially in the pulmonary vascular tree. Disturbances in pulmonary gas exchange were a result of deficient ventilation of lung areas damaged primarily by acid and suffering secondarily from developing disturbances in pulmonary blood flow. Dehydrobenzperidol in a dose of 1 mg/kg applied as the only treatment in Mendelson's syndrome had the same favourable effect on pulmonary changes as controlled IPPB. The combination of controlled artificial ventilation and intravenous dehydrobenzperidol decreased the disturbances in pulmonary gas exchange in Mendelson's syndrome. This was possible because both factors exert a benficial effect on ventilation and perfusion preventing the development of oedema and atelectasis.