In Reply:-We thank Uda et al. for their comments. We would like to mention that we also read their study with interest.

First, our study was planned according to the studies in which the incidence of pain when propofol was injected at 4 [degree sign]C or 37 [degree sign]C was less than that of pain when propofol was injected at room temperature. So we kept the propofol at 4 [degree sign]C and 37 [degree sign]C, as described by McCirrick and Hunter [1] and Fletcher et al., [2] respectively.

Second, whatever the cause of pain in veins, the perception of pain is the same because of the polymodal nociceptors that transmit their information via A [Greek small letter delta] fibers [3]; to abolish the injection pain of propofol, a method that can block A [Greek small letter delta] fibers must be used. Unfortunately, we do not think that propofol at 4 [degree sign]C or 37 [degree sign]C has such an effect. So we do not think that the effect of changes in the temperature of propofol are relevant.

Ertan Ozturk, M.D.

Seval Izdes, M.D.

Residents

Avni Babacan, M.D.

Associate Professor

Kadir Kaya, M.D.

Professor; Anesthesiology and Reanimation; The University of Gazi; Faculty of Medicine; Bahcelievler-Ankara, Turkey;eozturk@ato.org.tr

(Accepted for publication April 14, 1999.)

1.
McCirrick A, Hunter S: Pain on injection of propofol: The effect of injectate temperature. Anaesthesia 1990; 45:443-4
2.
Fletcher GC, Gillespie JA, Davidson JA: Propofol: The effect of temperature upon pain during injection of propofol. Anaesthesia 1996; 51:498-9
3.
Arndt JO, Klement W: Pain evoked by polymodal stimulation of hand veins in humans. J Physiol 1991; 440:467-78