Monitoring of liver oxygenation during neuroleptanalgesia in the dog.

In an animal study (7 mongrel dogs) the effects of neuroleptanalgesia (NLA) and combinations of NLA with nitrous oxide (N2O) and isoflurane on the macro- and microcirculation of the liver were investigated. Measurements were made in three steps. After NLA alone the dogs were supplementarily ventilated with nitrous oxide/oxygen at a ratio of 2:1. During the last step, 1 MAC isoflurane was added to the inspired gas. From the portal vein, arterial and mixed-venous systems' hemodynamic parameters, blood gases, and acid-base balance were recorded. As a parameter of oxygenation the tissue PO2 of the liver was measured with a multiwire surface electrode. During NLA stable hemodynamic conditions and a balanced acid-base status were observed. The nitrous oxide combination resulted in an increase of the mean pulmonary artery pressure of 16%. The addition of isoflurane had a negative inotropic effect: The heart index decreased to 74% of the starting value and the total peripheral resistance (TPR) increased by 27%. The summarized PO2 histograms under NLA and NLA/N2O showed arithmetic mean values of 34.1 and 35.2 mm Hg, respectively. The addition of isoflurane resulted in a left shift and a decrease of the mean value to 28.6 mm Hg. This histogram corresponds exactly to the oxygen pressure distribution in the dog liver during piritramide basic anesthesia. It seems that NLA and the combination of NLA/N2O increase the liver perfusion with a higher portal-venous and tissue PO2. This effect can be explained only by a massive change of visceral circulation. It is canceled by the addition of isoflurane.

Midazolam does not antagonize fentanyl-mediated analgesia in surgical patients.

STUDY OBJECTIVE: To determine whether midazolam possesses a clinically significant antianalgesic action in surgical patients. DESIGN: Randomized, controlled study. SETTING: Inpatient anesthesia at a university department of neurosurgery. PATIENTS: 2 groups of 10 patients each who were scheduled for supratentorial brain surgery, did not have elevated intracranial pressure, and were free from systemic disease. INTERVENTIONS: Patients underwent anesthesia induction with hexobarbital, succinylcholine, and pancuronium; anesthesia was maintained with injections of droperidol-fentanyl (Group 1) or with midazolam-fentanyl (Group 2) following a predetermined repetitive dosing schedule, such that fentanyl 0.1 mg was injected upon predominant increases in heart rate, whereas droperidol 2.5 mg or midazolam 2.5 mg was injected upon increases in blood pressure. MEASUREMENTS AND MAIN RESULTS: Duration of anesthesia and invasiveness of surgery were similar in both groups. The amount of fentanyl required was 0.55 +/- 0.18 mg/hr (mean +/- SD) in Group 1 and 0.53 +/- 0.17 mg/hr in Group 2. Injections of droperidol 7.5 +/- 3.4 mg/hr (Group 1) and midazolam 5.9 +/- 2.3 mg/hr (Group 2) were administered intraoperatively. This redosing regimen was associated with uninterrupted hemodynamic stability, indicating comparable and adequate anesthetic depth. Plasma concentrations of metabolites and hormones indicative of humoral stress activation did not differ between groups. CONCLUSION: Under these clinical conditions, the administration of midazolam, when compared with droperidol, was not associated with signs of any antagonistic or antianalgesic action toward fentanyl-mediated analgesia.

A simple, cheap, effective and safe procedure for general anesthesia.

A simplified, safe and flexible technique of anesthesia, based on a limited number of relatively cheap drugs, and allowing ventilation with air, was applied to 60 patients undergoing operations of at least 60 minutes' duration. The required depth of hypnosis was produced by intravenous diazepam or gamma-OH, whilst droperidol and fentanyl provided a satisfactory degree of sedation and analgesia. Pancuronium bromide was used for muscle relaxation. Spontaneous respiration was resumed immediately after postoperative use of nalorphine and neostigmine. The anesthetic course was smooth and predictable, with cardiovascular stability and an uneventful postoperative recovery. Emphasis is laid on the suitability of this procedure on the Battle Field or in Developing Countries, and on its safety (no toxic volatile liquids). (Acta anaesth. belg., 1976, 27, 25-34).

[Hemodynamic and hormonal study of electronarcosis and neuroleptanalgesia. Clinical study in 17 surgical patients]. / Etude hémodynamique et hormonale de l'anesthésie électro-médicamenteuse et de la neuroleptanalgésie. Travail clinique chez 17 opérés.

The blocking effect of electropharmaceutical anesthesia (EPA) and neuroleptanalgesia (NLA) on adrenergic and hormonal reactions to abdominal surgery were compared in 17 ASA class I to III randomized patients. This study was intended to define the indications for each of these techniques in patients with heart diseases. Each individual received the same anesthetic premedication and induction and was submitted to iterative identical measurements and biological dosages. Before and during surgery, both groups were catheterized with a Swan-Ganz and a radial catheter. Blood sampling for catecholamines, cortisol, glycemia, blood gases dosages were regularly drawn. Electrical stimulation was performed in the EPA group, and fentanyl injections were repeated in the NLA group patients only. The same doses of pancuronium and droperidol were given to every patient. A circulatory hyperkinesia and hyperadrenergia were observed during surgery in all of the subjects but, during EPA, the tachycardia, the cardiac index and the rate-pressure product were higher than during NLA. The body temperature increased towards normal in EPA, not in NLA. Adrenergic and hormonal levels were equal in both groups. The slow variations of all the important parameters demonstrate that the measured phenomenons have a long time-course what legitimates this kind of prolonged on-the-spot observation. The role of droperidol, pancuronium and fentanyl in the observed variations is discussed. The characteristic high hyperkinesia in EPA may be due partly to an inefficacious analgesia because of the fentanyl suppression after induction, partly to the preserved thermogenesis partly to a direct effect of the electrical stimulation on cerebral tissues.

[Is it necessary to discontinue captopril before heart surgery?]. / Faut-il arrêter le captopril avant l'opération en chirurgie cardiaque?

Interaction between kininase II and anaesthesia is not well described. Twenty two patients treated by kininase II for congestive heart failure are studied during anaesthesia for cardiovascular surgery. A first group of seventeen homogeneous hemodynamic data are reported. High cardiac index contrasts with severe clinical cardiac failure. A second group of inhomogeneous patients are separately described. Vasoconstrictor can be codified in the situation of low systemic resistance with high cardiac index. Preoperative treatment can be continued, under requirement of hemodynamic monitoring.

Postoperative arterial oxygen tension after peroperative PEEP-ventilation.

Forty otherwise healthy patients (29 women and 11 men), undergoing elective cholecystectomy, were randomly allocated to be ventilated during the operation either with a positive end-expiratory pressure of 1 kPa (10 cmH2O) (PEEP group) or with intermittent positive pressure ventilation without PEEP (control group). During the operation the mean arterial oxygen tension (PaO2) in the PEEP group increased from 14.6 to 16.5 kPa, while no changes occurred in the control group (13.5 and 13.6 kPa). On the first postoperative day, PaO2 decreased by 12% of the preoperative values in the PEEP group; the decrease was 20% in the control group. On the third postoperative day, the PaO2 in the control group was still 9% below the preoperative values, but on the fifth day, both groups had reached their preoperative PaO2 values. In the postoperative period, no statistically significant difference in PaO2 could be demonstrated between the groups. Determinations of the forced vital capacity and forced expiratory volume in the first second showed no difference between the groups pre- or postoperatively. The present study demonstrated no clinically relevant beneficial effect of peroperative PEEP ventilation on the postoperative arterial hypoxaemia after an upper abdominal laparotomy.

[Anesthesia for cardiovascular surgery under extracorporeal circulation: the authors' own technic]. / Anestesia per chirurgia cardiovascolare in C.E.C.: una tecnica personale.

The A. describe a technique of general anaesthesia for open-heart surgery, induced with Althesin and Fentanyl, in 29 patients submitted to cardiac and aortic surgery, and relate the results obtained. The experience showed the effectiveness of the reduction of peripheral vascular resistances due to Althesin, as well as usefulness of collateral techniques (cortisonic drug, carbon dioxide mixture, hypothermia, beta-adrenergic block, coronary vasodilation) employed for these patients during cardiopulmonary bypass.

[Trans-cerebral electric analgesia: reality, hypothesis or placebo? (author's transl)]. / Electro-analgésie transcérébrale: réalité, hypothèse ou placebo?

Sixty patients undergoing major digestive surgery received the same amount of drugs for induction of anesthesia; neuroleptic, morphinomimetic and pachycurares were used and calculated in mg/kg. A randomisation list permitted to define 45 patients who received in double blind (by means of a long electrical cord), an electrical current varying for each protocol; the control group (15 patients) did not receive an electrical current. Statistical study of the amount of drugs used for follow of anesthesia shows no real effect of electrical analgesia for digestive surgery.

Effect of premedication on the induction dose of thiopentone in children.

The effective dose of thiopentone in 90% ( ED90 ) of unpremedicated children is 10.5 mg/kg. This is significantly greater (p less than 0.01) than in premedicated children. The ED90 in children premedicated with TDP (a mixture of trimeprazine , droperidol and physeptone with atropine) is 4.2 mg/kg which is significantly less (p less than 0.05) than with trimeprazine and atropine ( ED90 5.2 mg/kg) or papaveretum and hyoscine ( ED90 5.0 mg/kg).

Anaesthesia in patients with phaeochromocytoma.

The authors' technique of balanced neuroleptanaesthesia with droperidol, fentanyl, nitrous oxide, pancuronium and nitroprusside is outlined. It is suggested that this is the anaesthetic method of choice for the surgical removal of catecholamine secreting tumours since it is associated with good operating conditions and an uneventful post-operative period.

Midazolam-droperidol premedication for cardiac surgery. A comparison with papaveretum and hyoscine.

A combination of midazolam and droperidol given intramuscularly was compared with papaveretum and hyoscine for premedication of patients about to undergo cardiac surgery. Midazolam and droperidol proved to be a very satisfactory combination, producing superior sedation and anxiolysis with good cardiovascular stability.

[Althesin in general surgery]. / L'althesin in chirurgia generale.

An account is given of the employment of althesin as an induction and maintenance anaesthetic. It is free of the drawbacks observed with thiopentone induction, and has negligible haemodynamic and respiratory effects. Its association with leptophen permitted excellent analgesia at minimal leptophen doses, without secondary effects either during or after anaesthesia. When there was a surgical need for relaxation, enhancement of the action of Pavulon was observed. Althesin enables volatile anaesthetics to be dispensed with. Quick and undramatic reawakening is another attractive feature of anaesthesia with this new drug.

Dose-related tachycardia induced by pancuronium during balanced anaesthesia with and without droperidol.

Pancuronium 0.02--0.08 mg kg-1 induced a dose-related increase of heart rate in patients anaesthetized with nitrous oxide supplemented with either fentanyl 0.003 mg kg-1 or fentanyl 0.003 mg kg-1 plus droperidol 0.15 mg kg-1. The tachycardia was more marked following the administration of droperidol.

Respiration, circulation and anaesthetic management in obesity. Investigation before and after jejunoileal bypass.

Some ventilatory and circulatory parameters were studied in 17 very obese patients before and after weight reduction following jejunoileal bypass. A low vital capacity and signs of impaired lung function with intrapulmonary shunting, increased alveolar-arterial Po2 difference and low Pao2 were found. Although the spirometric values improved significantly after weight reduction, the ventilatory disturbance persisted. A normal response to inhalation of CO2 was seen. The total blood volume was high and did not change after weight reduction. However, if calculated as blood volume per kg body weight, the values were lower than normal, and they increased as a consequence of weight reduction. Cardiac output was slightly lower than normal in relation to oxygen consumption. Total peripheral resistance was normal. Arterial blood pressure, which was in the high normal range preoperatively, decreased significantly after weight reduction. Total doses of intravenous anaesthetic agents and muscle relaxants were the same as for patients of normal weight. The importance of preoperative evaluation and of respiratory care of obese patients undergoing elective surgery is stressed.

[Changes of intraocular pressure in healthy-eyed patients under neuroleptanalgesia in abdominal surgery (author's transl)]. / Das Verhalten des intraoculären Druckes Augengesunder bei Eingriffen in Neuroleptanalgesie in der Abdominalchirurgie.

Ocular pressure was measured in 60 patients under neuroleptanalgesia with three different modes of induction (N2O, ketamine, thiopentone), during abdominal operations lasting at least one hour. The effect of premedication, of three different induction agents and of decurarisation on intraocular pressure were tested. It became apparent that after premedication and during the induction stage a decline of intraocular pressure (IOP) occured but did not last longer than 60 minutes. Decurarisation had no influence on the IOP. The causes of these changes and discussed.

[Sodium and water balance and renal function in volume expanded dogs under neuroleptanalgesia (author's transl)]. / Natrium- und Wasserbilanz beim Hund im Wachzustand und unter verschiedenen Narkosebedingungen. III. Mitteilung: Neuroleptoanalgesie

In 8 volume expanded dogs with an equilibrium between input and renal output of sodium and water neuroleptanalgesia of 6 hours duration with a total of 9 mg/kg of droperidol and 0.35 mg/kg of fentanyl was performed. Under anaesthesia GFR was increased by about 10% (p less than 0,02) compared with the conscious state, whilst renal sodium and water excretion was reduced by about 50%. From this we conclude that active tubular transport of sodium is augmented under neuroleptanalgesia. Due to decreased excretion, retention of sodium and water increased during anaesthesia changes of functional ECFV tending into the same direction. Plasma volume and intravascular protein did not change under neuroleptanalgesia compared with the conscious state. Urine osmolality and negative free water clearance (TcH2O) increased by about 60% under droperidol and fentanyl. In volume expanded dogs under neuroleptanalgesia intravenous application of 0.5-1.0 mg of atropine resulted in a temporary water diuresis.