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V̇o 2 and V̇co 2 following tourniquet deflation
Author(s) -
Hoka S.,
Yoshitake J.,
Arakawa S.,
Ohta K.,
Yamaoka A.,
Goto T.
Publication year - 1992
Publication title -
anaesthesia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.839
H-Index - 117
eISSN - 1365-2044
pISSN - 0003-2409
DOI - 10.1111/j.1365-2044.1992.tb01960.x
Subject(s) - tourniquet , medicine , anesthesia , heart rate , blood pressure , zoology , biology
Summary We examined changes in O 2 uptake, CO 2 output, blood pressure and heart rate following tourniquet deflation in 23 patients undergoing orthopaedic surgery of the lower extremities. A pneumatic tourniquet was applied for periods ranging from 21 to 106 min (mean 51 min). Prerelease values of V̇o 2 (O 2 uptake at each min) and V̇co 2 (CO 2 output at each min) were 201 (37) and 174 (38) (mean (SD)) ml.min −1 respectively. Significantly, V̇o 2 and V̇co 2 increased by 55% and 80%, respectively, at 2 min after tourniquet release and returned to prerelease values within 8 min. The blood pressure fell significantly and the heart rate rose significantly. The increases in CO 2 output and O 2 uptake were dependent on the length of tourniquet inflation time; Y = 4.7 X (tourniquet time) +54, r = 0.88, (p < 0.001) for CO 2 , and Y = 1.3 X (tourniquet time) +99, r = 0.52, (p < 0.05) for O 2 . The slope of the increase in CO 2 output as a function in inflation time was 3.6 times greater than that of O 2 uptake. In conclusion, CO 2 output and O 2 uptake increased transiently after tourniquet deflation and the extent of the increase in CO 2 output is more than threefold as compared with that in O 2 uptake.