Acta anaesthesiologica Scandinavica
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Acta Anaesthesiol Scand · Jan 1977
The pressure-flow relations of the canine brain in acute mechanically induced arterial hypertension at different levels of cerebral blood flow.
Cerebral pressure-flow relations were studied in anaesthetized dogs during acute arterial hypertension, induced by compression of the thoracic aorta. In one group of animals steady state measurements were made with the radioactive gas elimination method. ⋯ At low or normal blood flows autoregulation was efficient up to pressures around 180-200 mmHg, while at higher flows the upper autoregulatory pressure limit was found at lower blood pressures. Above the autoregulatory limit-irrespective of the control flow level-there was a rise in blood flow and a decrease in cerebrovascular resistance.
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Acta Anaesthesiol Scand · Jan 1977
Systemic and regional blood flow during epidural anesthesia with epinephrine in the Rhesus monkey.
Hemodynamic and regional blood flow measurements were made in five rhesus monkeys before and 10, 20, 40 and 80 min after induction of high epidural anesthesia (T1) with lidocaine (1%) containing 1:200,000 epinephrine. Following induction of epidural anesthesia with epinephrine, there were significant decreases in heart rate, mean arterial pressure, cardiac output and myocardial and renal blood flow. ⋯ Vascular resistance in the lower extremity was significantly decreased during anesthesia, indicating arteriolar dilatation. Also, during anesthesia, the lungs received a significantly increased proportion of the microspheres, suggesting an increased peripheral arteriovenous shunting of microspheres due to the arteriolar dilatation.
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Acta Anaesthesiol Scand · Jan 1977
Arrhythmias during halothane anaesthesia II: the influence of atropine.
The effect of i.v. atropine premedication on cardiac rhythm was studied in healthy adult patients during thiopental-N2O/O2-halothane anesthesia without intubation. A higher incidnece of arrhythmias was seen in younger patients in close relation to administration of atropine, but the overall incidence during anesthesia was identical in atropine groups and the control groups. ⋯ No consistent changes in blood pressure were observed as the result of arrhythmias or changes in heart rate. It is concluded that atropine should be reserved for situations where severe bradycardia and hypotension occur, or can be expected to occur, and not given automatically, since cardioacceleration which is inherent in its action may be injurious to patients with limited cardiac reserve.
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Acta Anaesthesiol Scand · Jan 1977
Catheter technique in axillary plexus block. Presentation of a new method.
A flexible, disposable intravenous catheter can be introduced into the neuro-vascular sheath in the axilla and used for injection of local anesthetic solution to block the axillary brachial plexus. The technique is described and the results of the first 137 consecutive catheter blocks are reported and compared to a similarly evaluated series of conventional axillary blocks. The catheter method constitutes an interesting alternative to needle techniques and offers the possibility of a continuous axillary block.
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Acta Anaesthesiol Scand · Jan 1977
Peripheral nerve injury due to injection needles used for regional anesthesia. An experimental study of the acute effects of needle point trauma.
Nerve injury can arise as a complication peripheral nerve block anesthesia. Of the various factors involved, the trauma caused by the injection needle may be of significance. ⋯ Fascicular injury was indicated by a fluorescence microscopy technique, tracing locally applied Evans Blue Albumin, The results show that a 45 degrees-beveled needle less frequently produces fascicular damage and should therefore be recommended for use in clinical anesthesia. It is also concluded that paresthesiae, when necessary, should be elicited gently, and that intraneural injections should be avoided.