[Comparative study of the effect of muscle relaxants on the intraocular pressure]. / Vergleichende Untersuchung zur Wirkung von Muskelrelaxantien auf den intraokulären Druck.

Control of intraocular pressure is a major concern in ophthalmic anesthesia, especially in the presence of glaucoma or penetrating eye injury. The use of succinylcholine under these conditions is controversial. This study was undertaken to assess the effects of the neuromuscular blocking agents succinylcholine, pancuronium, metocurine, vecuronium, and atracurium on the intraocular pressure of dogs. The study was performed on five "conditioned" mature male foxhounds. The dogs were intubated immediately after induction with thiopental 10 mg/kg and ventilated with an O2/N2O mixture (FIO2 = 0.33). The ventilation was controlled to maintain an endtidal CO2 concentration of 5 vol.%. and anesthesia maintained with a fentanyl infusion of 10 micrograms/kg per hour. Direct and continuous measurements were taken of blood pressure (MAP), central venous pressure (CVP), and intra-ocular pressure (IOP), the latter via a 22-gauge needle inserted into the anterior chamber of the eye. A force-displacement transducer was attached to the hindpaw to monitor muscle twitch following supramaximal stimulation of the anterior tibial nerve. These four measurements were displayed on a multi-channel polygraph (Figs. 1 and 2). Control values were obtained and then succinylcholine 1 mg/kg, pancuronium 0.1 mg/kg, metocurine 0.3 mg/kg, vecuronium 0.1 mg/kg, or atracurium 0.4 mg/kg were given in a randomized fashion and on different days. Measurements of heart rate (HR), MAP, CVP, and IOP were noted at 2, 5, 10, 20, and 30 min after giving the neuromuscular blocking agent. The results, as displayed on the polygraphy, indicate that the least effect on IOP and cardiovascular state followed neuromuscular blockade with vecuronium and atracurium.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparative study of analgesia and plasma level following rectal, intramuscular and intravenous administration of ketamine]. / Vergleichende Untersuchung von Analgesie und Plasmaspiegeln nach rektaler, intramuskulärer und intravenöser Gabe von Ketamin.

Ketamine 25 mg/kg was administered to five foxhounds by the intravenous, intramuscular or rectal route. Plasma concentrations were measured by gas-chromatography and analgesia was tested by two techniques. Intravenous application gave reliable analgesia and well reproducible plasma levels in all subjects. Distribution and elimination half lives were found to be 6 min and 55 min, respectively. Intramuscular injection resulted in peak-plasma levels around the twentieth minute, elimination half life was fifty-two minutes, bioavailability 90%. Analgesia proved satisfactory in four out of the five subjects and lasted longer than after intravenous injection. The rectal route produced a wide range of peak-plasma levels, the average peak appearing after 40 min. We found an elimination halflife of 43 min and a bioavailability of 30%. Analgesia was poor in four out of the five subjects. The low plasma levels following rectal application are due to the poor bioavailability and this appears to be the reason for the unsatisfactory results with this route of administration. Bioavailability depends on the site of application (drainage mainly through the vena cava or portal vein) and the pH of the rectum.

Surgical treatment of an arteriovenous malformation of the mandible in a child. A case report.

Arteriovenous malformations of the mandible are rare and potentially life threatening lesions. They are very unusual in young individuals. A case is reported in which a form of surgical treatment is advocated that permits preservation of the continuity of the mandible and the dentition with little potential for life threatening bleeding.

[A new tube for laser surgery of the larynx]. / Ein neuer Tubus für Laser-Eingriffe am Larynx.

A special tube for laser-surgery of the larynx ("Surgitek-Laser-Tube") was exposed to a CO2-Laser beam (Cavitron AO 300). In the common clinical range of settings, the tube proved to be relatively Laser-resistant. Increasing exposure resulted in damage to the surface and cuff. Also the metal coating decreased the I.D. significantly, which resulted in an unfavourable ratio of inner to outer diameter.