Premium
Effects of nitrous oxide on cerebral haemodynamics and metabolism during isoflurane anaesthesia in man
Author(s) -
Algotsson L.,
Messeter K.,
Rosén I.,
Holmin T.
Publication year - 1992
Publication title -
acta anaesthesiologica scandinavica
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.738
H-Index - 107
eISSN - 1399-6576
pISSN - 0001-5172
DOI - 10.1111/j.1399-6576.1992.tb03420.x
Subject(s) - isoflurane , medicine , anesthesia , hypocapnia , cerebral blood flow , nitrous oxide , cerebral circulation , fentanyl , hemodynamics , electroencephalography , oxygen metabolism , oxygen , acidosis , hypercapnia , chemistry , psychiatry , organic chemistry
Seven normoventilated and five hyperventilated healthy adults undergoing cholecystectomy and anaesthetized with methohexitone, fentanyl and pancuronium were studied with measurement of cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRo 2 ), and quantified electroencephalography (EEG) under two sets of conditions: 1) 1.7% end‐tidal concentration of isoflurane in air/oxygen; 2) 0.85% end‐tidal concentration of isoflurane in nitrous oxide (N 2 O)/oxygen. The object was to study the effects of N 2 O during isoflurane anaesthesia on cerebral circulation, metabolism and neuroelectric activity. N 2 O in the anaesthetic gas mixture caused a 43% ( P <0.05) increase in CBF during normocarbic conditions but no significant change during hypocapnia. CMRo 2 was not significantly altered by N 2 O. EEG demonstrated an activated pattern with decreased low frequency activity and increased high frequency activity. The results confirm that N 2 O is a potent cerebral vasodilator in man, although the mechanisms underlying the effects on CBF are still unclear.