High Thoracic Segmental Epidural Anesthesia Diminishes Sympathetic Outflow to the Legs, Despite Restriction of Sensory Blockade to the Upper Thorax

Intestinal effects of thoracic epidural anesthesia

“…In humans, thoracic skin temperature remained unchanged or even decreased as a sign of increased activity of thoracic sympathetic nerves in TEA using 4.2 ml bupivacaine 0.75% injected at Th6-Th9 [12]. Similarly, in conscious dogs and anesthetized rats, indirect measurement of thoracic skin sympathetic activity failed to show inhibition of sympathetic activity, whereas both front and hind paws showed signs of sympathetic block in these studies [9,13].…”

“…In humans, limited upper thoracic sensory block reaching Th6 occurred during high TEA induced by 4.2 ml bupivacaine 0.75%. In these patients, skin temperature in the feet also increased, suggesting unrestricted sympathetic block including splanchnic segments [12]. In contrast to this, 4 ml bupivacaine 0.5% injected at Th4 induced sensory block down to Th8 but did not affect sympathetic activity in the lower legs [11].…”

“…In contrast to this, 4 ml bupivacaine 0.5% injected at Th4 induced sensory block down to Th8 but did not affect sympathetic activity in the lower legs [11]. Therefore, the concentration of local anesthetic might not only determine the intensity but also the extent of the sympathetic block, probably by the degree of intraspinal resorption of local anesthetic [12,15]. However, in clinical practice of high thoracic TEA, most often larger volumes of lower concentrations of local anesthetics are used [16,17].…”

Distal infrared thermography and skin temperature after ultrasound-guided interscalene brachial plexus block

“…13,14 High thoracic epidural anaesthesia probably leads to increased Ts in all parts of the hand, although this has not been investigated in detail. 15,16 Peripheral median nerve block leads to increased Ts in the first to fourth digits and peripheral ulnar nerve block leads to increased Ts in the fourth and fifth digits. 6 However, this knowledge does not allow us to predict the thermographic patterns after a proximal brachial plexus block, as we have demonstrated.…”

Thorakaler Periduralkatheter: Sinnvoll oder Überinstrumentierung?

“…Die thorakale PDA blockiert transient und segmental den Sympathikus und ist in der Lage, eine Vielzahl der oben beschriebenen perioperativen Effekte zu modulieren, wobei eine funktionelle Verbesserung in den experimentellen und klinischen Untersuchungen nicht immer klar nachweisbar war [41]. Die hämodynamischen Effekte durch die Sympathikolyse nach thorakaler PDA mit Lokalanäs-thetika können dosis-und substanzabhängig bis zu 6 Tage postoperativ anhalten, die Splanchnikusperfusion verbessern und myokardial ischämische Ereignisse verhindern [17,[42][43][44]. Die thorakale PDA ist durch die Modulation der perioperativen physiologischen und neurohormonellen Funktionen fester Bestandteil der "Fast-Track"-Konzepte.…”