Anesthesia and analgesia
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Anesthesia and analgesia · Jan 1980
Comparative StudyWithdrawal convulsions in mice following nitrous oxide.
Mice may be induced to convulse after (but not prior to) breathing nitrous oxide. We found that the incidence of this withdrawal phenomenon is related to the partial pressure of nitrous oxide. A minimum (threshold) value of about 0.5 atm is necessary and the majority of mice convulse following exposure to 0.9 atm or greater. ⋯ The mice remain susceptible to the induction of convulsions for only a brief period after removal from nitrous oxide. Although the duration of susceptibility is slightly increased after exposure to higher partial pressures, susceptibility in almost all cases is lost by 90 minutes. In mice, exposure to nitrous oxide is associated with evidence of physical dependence as evidenced by withdrawal symptoms, symptoms that be related to the appearance of excitement which sometimes follows nitrous oxide anesthesia.
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Anesthesia and analgesia · Jan 1980
Comparative StudyPercutaneous cervical central venous line placement: a comparison of the internal and external jugular vein routes.
To compare the rate of success and incidence of complications associated with two currently popular routes of percutaneous central venous cannulation, we studied 167 patient in whom either internal or external jugular vein catheterization was attempted. Internal jugular vein (IJV) catheterization (125 patients) was successful in 91%; an intrathoracic location was achieved in 100%; complications occurred in 12.8%. Complications included one case of catheter malposition, one case of tension pneumothorax, and 12 instances of inadvertent carotid artery puncture, one resulting in a paratracheal hematoma and phrenic nerve compression. ⋯ External jugular vein cannulation (42 patients), using a "J" wire technique, yielded a 76% success rate: 93.7% of catheter tips reached an intrathoracic location. No complications occurred. We conclude that IJV cannulation is a more reliable means of percutaneous central venous line placement but is associated with a significant incidence of complications which can be reduced if a technique employing a scout needle and guide-wire is used.