Regional Skin Temperatures Associated With Total Sympathetic Blockade in Conscious Dogs

Abstract

Multiple regional skin temperatures were measured continuously before and after complete sympathetic nerve block by extradural anaesthesia in conscious dogs in environmental temperatures slightly below (22.4 (SEM 0.4) degrees C) and slightly above (27.2 (0.4) degrees C) the thermoneutral range. In the cold environment, skin temperature increased in the distal (+2.13 degrees C, P less than 0.001) and proximal (+1.1 degrees C, P less than 0.02) front limbs and distal (+3.25 degrees C, P less than 0.001) and proximal (+1.72 degrees C, P less than 0.001) hind limbs, but decreased on the chest (-0.83 degrees C, P less than 0.01) and abdomen (-0.67 degrees C, P less than 0.002). Similar changes (all significant) were seen in the warm environment, although the effects were smaller. Rectal temperature did not change during the experiments. Arterial pressure decreased in both groups after denervation, but was the same in the denervated state regardless of ambient temperature. Our results are incompatible with increased sympathetic discharge from unblocked regions being a dominant factor in the decrease in trunk skin temperature above and within the analgesic areas, and demonstrate a substantial contribution of the sympathetic nervous system to the maintenance of the normal skin temperature gradient along the long axis of the body.

Effects of thoracic epidural anesthesia and adrenoceptor blockade on the cardiovascular response to dopamine in the dog

“…TEA was established with a bolus injection of mepivacaine 10 mg. kg-' (Carbocain" 20 mg.ml-l, Astra, Sweden), i.e. a similar dosage to that used previously during epidural anesthesia in dogs (18)(19)(20). Mepivacaine was then continuously infused epidurally at 5 m g ' k g -' .…”

Effects of epidural anesthesia on sympathetic nerve discharge to the skin

“…As previously discussed (16), caution must be exercised when relating changes in skin temperature directly to changes in sympathetic function. Recent observations by Arndt and coworkers may also partly explain these diverging findings (17). They showed that high epidural block in dogs was associated with increased skin temperature in both hind and front limbs while trunk skin temperature fell.…”

Avaliação da dispersão da bupivacaína na anestesia peridural em cães

“…Sendo a bupivacaína o anestésico local mais utilizado, muitos relatos avaliam sua aplicação na anestesia peridural em cães enfocando bloqueios motor, sensitivo e autonômico (Feldman e Covino, 1988;Peters et al, 1988;Feldman et al, 1996;Feldman et al, 1997;Goméz de Segura et al, 2000). Nessas investigações têm sido testadas sua eficiência ou toxicidade de maneira isolada ou em combinação com outros fármacos (Timour et al, 1987;Peters et al, 1989;Hendrix et al, 1996;Goméz de Segura et al, 2000).…”

“…O bloqueio sensitivo também é avaliado pelo estímulo de introdução de uma agulha na pele dos cães e observação da contração dessa (Peters et al, 1988;Peters et al, 1989). Peters et al (1988) e Peters et al (1989) realizaram estudos relevantes a respeito da obtenção de bloqueio autonômico associado à temperatura cutânea em cães.…”

“…Peters et al (1988) e Peters et al (1989) realizaram estudos relevantes a respeito da obtenção de bloqueio autonômico associado à temperatura cutânea em cães. Observaram a ocorrência dessa associação em virtude do bloqueio de nervos simpáticos causar vasodilatação com conseqüente aumento da circulação sanguínea e temperatura local.…”