Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Jan 1978
Longitudinal spread of intraneurally injected local anesthetics. An experimental study of the initial neural distribution following intraneural injections.
Unexpected spinal anesthesia, occurring after peripheral nerve blocks close to the spine, may be caused by a centripetal spread of the local anesthetic along the injected nerve to the spinal cord. In order to analyze the pathway of such a spread, a radioactive local anesthetic mixed with a fluorescent dye was injected into difrerent compartments of the rabbit sciatic nerve, and the early distribution of these tracers was studied by scintillation counting and fluorescence microscopy. Epineurial (extrafascicular) injections were of low injection pressure (25-60 mmHg) (3.3-7.9 kPa) and limited spread, while endoneurial (intrafascicular) injections reached higher pressures (300-750 mmHg) (39.9-99.7 kPa) and caused a rapid spread over long distances within the fascicle. ⋯ However, 20% of endoneurial injections reached the spinal cord, where the injectate primarily spread in the thin subpial space. Our experimental findings suggest that intraneural injections of local anesthetics are responsible for the reported cases of unexpected spinal anesthesia due to inadvertent intrafascicular spread. Although intrafascicular injections are rarely made, we recommend that intraneural injections of local anesthetics or other solutions close to the spine should be avoided, as they may cause unexpected spinal anesthesia or lesion of the cord.
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Acta Anaesthesiol Scand · Jan 1978
Acute effects of furosemide and mannitol on central haemodynamics in the early postoperative period.
The effects of furosemide and mannitol on central haemodynamics in the early postoperative period were investigated in 16 patients, who had undergone upper abdominal surgery. Measurements were performed prior to, and then 10, 30, 50 and 90 min after postoperative drug administration. ⋯ Systemic vascular resistance decreased. It is concluded that mannitol should be used as the diuretic of choice in the treatment of postoperative (post-traumatic) oliguria in patients without known cardiovascular disease.
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Acta Anaesthesiol Scand · Jan 1978
Cardiovascular effects of local adrenaline infiltration during halothane anaesthesia and adrenergic beta-receptor blockade in man.
Adrenergic beta-receptor blocking agents, alprenolol, propranolol and practolol were given as a prophylactic measure to patients undergoing middle-ear microsurgery where adrenaline was deliberately infiltrated during halothane-N2O/O2 anaesthesia. These three beta blockers did not differ in their action on heart rate, arterial blood pressure, right ventricular pressure, CVP or peripheral pulse wave in equipotent doses, which were 0.04 mg/kg for alprenolol and propranolol and 0.4 mg/kg for practolol in this study. ⋯ Occasionally occuring tachyarrhythmias were easily terminated with a further dose of a beta blocker. The effective half-life of practolol was less than 15 min and doses up to 0.4 mg/kg were unable to prevent arrhythmias during adrenaline challenge.
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Acta Anaesthesiol Scand · Jan 1978
Occupational hazards to reproduction and health in anaesthetists and paediatricians.
A mail questionnaire was sent to Finnish anaesthetists and paediatricians to evaluate the risks of reproductive, teratogenic and health complications related to the professions. The incidence of diagnosed spontaneous miscarriages in anaesthetists' families was 10.2% of all pregnancies and it was 13.2% in paediatricians' families. Smoking seemed to increase markedly the incidence of spontaneous miscarriages, which was 22.9% in smoking female anaesthetists and 17.2% in smoking female paediatricians. ⋯ Different infectious diseases to the respiratory and urinary tracts were commonest among paediatricians. Cancer was not reported in the anaesthetist group. The study does not indicate that gas pollution in operating rooms is harmful to the personnel.
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Acta Anaesthesiol Scand · Jan 1978
Comparative StudyEEG-changes during general anaesthesia with enflurane (Efrane) in comparison with ether.
The effects of enflurane (efrane) and ether on the cerebral functions were studied by EEG on two similar groups of adult patients. For basic comparison a depth of anaesthesia was chosen which permitted abdominal surgery without the need to administer muscular relaxants. ⋯ If, however, the depth of anaesthesia was further increased, such EEG-changes indicating increased cerebral excitability were seen more often under enflurane and also appeared under ether anaesthesia. No seizure activity was recorded.