The Effect of Total Sympathectomy on the Occurrence of Shock From Hemorrhage

TRAUMATIC SHOCK. IX. PRESSOR THERAPY: THE EFFECT OF PAREDRINE (p-Hydroxy-a-Methylphenylethylamine Hydrobromide) ON THE CIRCULATION IN HEMORRHAGIC SHOCK IN DOGS 12

“…This is in contrast to unsympathectomized animals in which blood pressure is maintained or tends to return toward normal until 30 to 50 per cent of the blood volume is removed. This author's data (6) do not indicate whether the sympathectomized dog is more resistant to the development of shock by bleeding than an unsympathectomized dog suffering the loss of the same volume of blood. Other workers (7) found that the removal of 12 to 15 per cent of the blood volume of sympathectomized cats resulted in irreversible shock, whereas the normal animal tolerated the withdrawal of 40 percent.…”

“…His conclusion that the elimination of sympathetic vasoconstriction delayed the onset of "shock" can be questioned because the sympathectomized animals were bled less to reach the shock blood pressure level and accordingly had larger blood volumes. Thus, in totally sympathectomized animals, the arterial blood pressure falls in proportion to reduction in blood volume, reaches low levels after withdrawal of only 10 to 20 per cent of blood volume, and shows no tendency to recover after cessation of bleeding (6,7). This is in contrast to unsympathectomized animals in which blood pressure is maintained or tends to return toward normal until 30 to 50 per cent of the blood volume is removed.…”

“…Samples of blood from the external jugular, portal, and femoral veins gave no evidence of preferential improvement in the flow through any of these beds (Table IA) In an effort to determine whether this reflected an increase in cerebral blood flow, the oxygen content of the blood of the superior sagittal sinus was analyzed before and during the period of (6) found that, at a given blood pressure level in shock, sympathectomized dogs had a greater volume flow through the paw than non-sympathectomized animals. His conclusion that the elimination of sympathetic vasoconstriction delayed the onset of "shock" can be questioned because the sympathectomized animals were bled less to reach the shock blood pressure level and accordingly had larger blood volumes.…”

Course of Hemorrhagic Shock After Blockade of Norepinephrine Release

“…Circulating catecholamines originating from the adrenal medulla prob ably account for the residual rise in plasma lactate and for the preserva tion of the lipolytic response to hemorrhage since shocked animals sub jected to complete autonomic blockade show none of these responses [Hl-In stressful situations the sympathetic nervous system is considered in dispensable in maintaining bodily homeostasis and, accordingly, tolerance to severe blood loss is adversely affected by total [3,4,18] or partial [9] surgical sympathectomy. Diminished tolerance to blood loss after chemi cal sympathectomy with bretylium is, therefore, consistent with these ear lier observations.…”

A new approach to the control of shock

“…Stuches are m progress to correlate pulmonary artery pressure, minute volume, and arterial oxygen with stritcmg chnical improvement of pulmonary oedema, tachycardia, urinary output, cyanosis, and dyspnoea under spinal anaesthesm. Pulmonary artery pressure wa,~ seen to drop [25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] ram. in two cases, the mmute volume to increase up to I~A litres (24).…”