[Core and cutaneous thermal changes in the upper limb after anesthesia induction].
OBJECTIVE
To describe and compare the core-cutaneous thermal and photoplethysmographic time-course effects after induction of general anesthesia with propofol, fentanyl and vecuronium.


METHODS
We measured digital blood flow, core temperature and skin temperature in the upper limb (fingertip, forearm and upper arm) in 20 patients (10 men and 10 women, ASA-I) before anesthetic induction and 5, 10, 15 and 20 min after induction. Skin temperature changes were recorded with disposable thermocouples. Blood flow was recorded by digital photoplethysmography (PhPl) in the thumb. Anesthesia was provided without premedication, using propofol (3 mg.kg-1), fentanyl (0.1 mg) and vecuronium (0.1 mg.kg-1). After endotracheal intubation, anesthesia was maintained with oxygen-nitrous oxide and 0.1 mg of intravenous fentanyl at the tenth minute, without inhaled anesthetics.


RESULTS
All patients showed intense, abrupt vasodilatation in the thumb with marked increases in PhPl (PhPl = 10.4 +/- 5.0 mV/V, at 5 min, p < 0.001) and fingertip temperature (TFingertip = 6.2 +/- 2.0 C, at 10 min, p < 0.001). However, skin temperature changes in the upper arm and forearm were moderate and slower (TForearm = 2.1 +/- 1.4 C, p < 0.01 and TUpper arm = 1.1 +/- 1.2 C, p < 0.01; at 20 min in both cases). A significant correlation was found only between PhPl and TFingertip (r = 0.55, p < 0.001).


CONCLUSIONS
Anesthetic induction with propofol, fentanyl and vecuronium produces cutaneous vasodilatation in the upper limb unequally: the greatest increase in skin temperature occurs at the fingertip, while forearm and upper arm temperatures increase less. We think that skin vasodilatation in peripheral distal areas may play an important role in redistributing core heat during anesthesia.
González de Zárate
J
J
Servicio de Anestesiología-Reanimación, Hospital Universitario, Universidad de Valladolid.
Olmos
A
A
Alvarez
J C
JC
Ruiz
N
N
de Andrés
B
B
González-Fajardo
J A
JA
D000771:Anesthesia, Intravenous; D001132:Arm / Q000502:physiology*; D001831:Body Temperature; D005260:Female; D005283:Fentanyl; D006801:Humans; D008297:Male; D008875:Middle Aged; D015742:Propofol; D014673:Vecuronium Bromide
D014673:Vecuronium Bromide; D005283:Fentanyl; D015742:Propofol