Author/Editor     Mekjavić, IB; Sundberg, CJ
Title     Human temperature regulation during narcosis induced by inhalation of 30% nitrous oxide
Type     članek
Source     J Appl Physiol
Vol. and No.     Letnik 73, št. 6
Publication year     1992
Volume     str. 2246-54
Language     eng
Abstract     The study investigated the effect of inhalation of 30 percent nitrous oxide (N2O) on temperature regulation in humans. Seven male subjects were immersed to the neck in 28 degrees C water on two separate occasions. They exercised at a rate equivalent to 50 percent of their maximum work rate on an underwater cycle ergometer for 20 min and remained immersed for an additional 100 min after the exercise. In one trial (AIR) the subjects inspired compressed air, and in the other trial (N2O) they inspired a gas mixture containing N2O (20.93 percent O2-30 percent N2O-49.07 percent N2). Sweating, measured at the forehead, and shivering thermogenesis, as reflected by O2 uptake, were monitored throughout the 100-min recovery period. The threshold core temperatures at which sweating was extinguished and shivering was initiated were established relative to resting preexercise levels. Neither the magnitude of the sweating response nor the core threshold at which it was extinguished was significantly affected by the inhalation of N2O. In contrast, shivering thermogenesis was both significantly reduced during the N2O condition and initiated at significantly lower core temperatures Šchange in esophageal temperature (delta T(es)) = -0.98 +/- 0.33 degrees C and change in rectal temperature (delta T(re)) = -1.26 degrees CĆ during the N2O than during the AIR condition (delta T(es) = -0.36 +/- 0.31 degrees C and delta T(re) = -0.44 +/- 0.22 degrees C).(ABSTRACT TRUNCATED AT 250 WORDS)
Descriptors     BODY TEMPERATURE REGULATION
INERT GAS NARCOSIS
NITROUS OXIDE
ADULT
EXERCISE
IMMERSION
OXYGEN CONSUMPTION
SHIVERING