Study on the Effect of Sevoflurane in Pediatric Clinical Anesthesia

Background The volatile anesthetic sparing effect of nitrous oxide in clinical studies is less than might be expected from the additivity of minimum alveolar concentration values. Other studies identify nonadditive interactions between isoflurane and nitrous oxide. The aim of this study was to quantify the interaction of isoflurane and nitrous oxide at a constant median electroencephalographic frequency. Methods Twenty-five patients were studied during laparotomies. Nitrous oxide was randomly administered in concentrations of 0, 20, 40, 60, and 75 vol%, to ten patients for each nitrous oxide concentration. Isoflurane vaporizer settings were chosen so that the median electroencephalographic frequency was held between 2 and 3 Hz. The relationship between nitrous oxide concentrations and required isoflurane concentrations was examined with the method of isoboles. Results Nitrous oxide linearly decreased the isoflurane requirement. Addition of every 10 vol% of nitrous oxide decreases the isoflurane requirement by approximately 0.04 vol%. The total anesthetic requirement of isoflurane and nitrous oxide, expressed in terms of previously reported minimum alveolar concentration values, increased significantly with increasing nitrous oxide concentrations. Conclusions The interaction of isoflurane and nitrous oxide in the dose range 0-75 vol% on median electroencephalographic frequency is compatible with additivity. The potency of nitrous oxide as a substitute for isoflurane is less than on a minimum alveolar concentration basis. Maintaining median electroencephalographic frequency more appropriately reflects the clinical usage of isoflurane and nitrous oxide than does maintaining minimum alveolar concentration.

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Case report: 2 cases of cardiac arrest caused by rhino-cardiac reflex while disinfecting nasal cavity before endonasal transsphenoidal endoscopic pituitary surgery

BMC Anesthesiology ◽

10.1186/s12871-021-01240-w ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Wen Wang ◽

Hongwei Cai ◽

Huiping Ding ◽

Xiaoping Xu

Keyword(s):

Risk Factors ◽

Blood Pressure ◽

Heart Rate ◽

Cardiac Arrest ◽

Case Report ◽

Nasal Cavity ◽

Pituitary Surgery ◽

Case Presentation ◽

Clinical Anesthesia ◽

Vagus Reflex

Abstract Background Trigeminal-cardiac reflex (TCR) is a brainstem vagus reflex that occurs when any center or peripheral branch of the trigeminal nerve was stimulated or operated on. The typical clinical manifestation is sudden bradycardia with or without blood pressure decline. The rhino-cardiac reflex which is one type of TCR is rare in clinical practice. As the rhino-cardiac reflex caused by disinfection of the nasal cavity is very rare, we report these two cases to remind other anesthesiologists to be vigilant to this situation. Case presentation This case report describes two cases of cardiac arrest caused by rhino-cardiac reflex while disinfecting nasal cavity before endoscopic transsphenoidal removal of pituitary adenomas. Their heart rate all dropped suddenly at the very moment of nasal stimulation and recovered quickly after stimulation was stopped and the administration of drugs or cardiac support. Conclusion Although the occurrence of rhino-cardiac reflex is rare, we should pay attention to it in clinical anesthesia. It is necessary to know the risk factors for preventing it. Once it occurs, we should take active and effective rescue measures to avoid serious complications.

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Ropivacaine magnetic nanoparticles: An efficient local anesthetic nerve conduction blocker

Materials Express ◽

10.1166/mex.2021.2098 ◽

2021 ◽

Vol 11 (11) ◽

pp. 1819-1825

Author(s):

Junying Su ◽

Xiaohu Chen ◽

Huizhang Liu ◽

Yuhui Luo

Keyword(s):

Magnetic Nanoparticles ◽

Postoperative Analgesia ◽

Local Anesthetic ◽

Temperature Response ◽

Nociceptive Pain ◽

Nerve Blocks ◽

Anesthetic Effect ◽

Field Of Vision ◽

Clinical Anesthesia ◽

The Stability

Ropivacaine (Rop) is one of the commonly used local nerve blocks in clinical anesthesia and postoperative analgesia and it inhibits the stimulation of peripheral nociceptive pain. However, Rop alone is not effective enough to exert a controllable anesthetic effect in patients with peripheral nociceptive pain. Therefore, there is an urgent need to improve the targeting of the local anesthetic effect of Rop and reduce its potential chronic or acute toxicity. In this study, a novel Rop nanocomposite hydrogel drug, N-isopropylacrylamide-methacrylic acid/ropivacaine magnetic nanoparticles (NIP-MAA/Rop MNPs), was constructed on magnetic iron oxide. The unique pH and temperature response of NIP-MAA can effectively retain magnetic properties, improve the stability and targeting controllability of magnetic nanoparticles, and avoid excessive drug diffusion. Therefore, the NIP-MAA/Rop MNPs is expected to open a new field of vision for the research of clinical anesthesia and postoperative analgesia.

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