Several reports also demonstrate significantly lower heart rate increases during exercise in subjects who have undergone bilateral ISS [9–12] compared to pre-surgical levels. In spite of this high occurrence, recent reviews on the usual collateral effects of thoracic sympathectomy still do not include these possible cardiac consequences [6].
The aim of the present prospective study was to confirm that a significant impairment of the heart rate to workload relationship was consistently observed following unilateral and/or bilateral surgery.
Eur J Cardiothorac Surg 2001;20:1095-1100
http://ejcts.ctsnetjournals.org/cgi/content/full/20/6/1095
Sunday, January 25, 2009
Palmar Hyperhidrosis worse after Sympathectomy
We describe a patient who underwent upper thoracic sympathectomy for palmar hyperhidrosis, and whose symptoms subsequently deteriorated, becoming worse than those on initial presentation.
Clinical and Experimental Dermatology
Volume 20 Issue 3, Pages 230 - 233
Published Online: 27 Apr 2006
Accepted for publication 6 January 1995
THE SYMPATHETIC NERVOUS SYSTEM AS A HOMEOSTATIC MECHANISM
The responses of intact rats to cold-exposure (4°C) include vasoconstriction, piloerection, shivering, adrenocorticotrophin (ACTH) hypersecretion and increased mobilization of free fatty acids and glucose. Adrenal demedullation prevents the increased mobilization of glucose and decreases survival time. Chemical sympathectomy blocks all of the responses except ACTH hypersecretion. Such animals lose body heat rapidly and die in a few hours. Total adrenalectomy has a similar effect. The damaging actions of chemical sympathectomy are reversed by administration of catecholamines while those of total adrenalectomy are reversed by cortisone. Thus, the sympathetic nervous system appears to be essential for existence at low environmental temperature.
http://jpet.aspetjournals.org/cgi/content/abstract/157/1/103
http://jpet.aspetjournals.org/cgi/content/abstract/157/1/103
All possible side effects should be dealt with and written informed consent required
Thoracoscopic sympathicotomy by electrocautery is an irreversible procedure. Thus the indications must be meticulously considered before the final decision to operate is taken by both the surgeon and the patient. All possible side effects should be dealt with and written informed consent required.
http://www3.interscience.wiley.com/journal/106568639/abstract?CRETRY=1&SRETRY=0
http://www3.interscience.wiley.com/journal/106568639/abstract?CRETRY=1&SRETRY=0
Published Online: 2 Dec 2003
Copyright © 2002 Taylor and Francis Ltd
Sympathectomy impairs temperature homeostasis, decreases Cardiac output and myocardial work
The decrease in body temperature associated with the onset of central neuraxial block has three reported mechanism: loss of the patient's thermorgulatory capability, with impaired shivering and loss of the ablility to sense cold temperatures; sympathectomy induced peripheral vasodilation, resulting in admixing of peripheral (cool) with core (warm) blood (this mixing results in a 1C to 2C decrease in core temperature and is proporitonal to the extent of sympathetic block and patient's age, and loss of tissue heat below the level of sympathectomy due to vasodilation.
Neuraxial anesthesia decreases afterload by producing arterial vasodilation. This vasodilation however is not equivalent in all vascular beds. For instance, muscle and skin blood flow may be decreased by sympathectomy, whereas the total blood flow to the same extremity may be quadrupled. Additionally, the extent to which afterload is decreased by sympathetic denervation varies considerably from one patient to another.
The effectiveness of this reflex vasoconstriction in maintaining normotension is a function of the extent of the sympathetic block. If, for instance, sympathetic block reaches the fourth thoracic dermatome (T4) or higher, the intact upper limb vasculature may contribute only 5% of the total cardiac output. Even maximal vasoconstriction will be insuffiecient to compensate for the profound arterial vasodilation in the rest of the body.
Cardiac Function
Importantly, bradycardia during high (thoracic) levels of spinal or epidural anesthesia is due to two main factors: denervation of preganglionic cardiac accelerator fibers (T1-4) and diminished venous return to the right ventricle because of decreases in preload.
Cardiac Output
The extent of CO decrease is also a function of the degree of sympathetic denervation.
Conversely, assumption of an even slight head-up position during neuraxial anesthesia with high levels of sympathetic denervation (..) may have catastrophic consequences such as profound bradycardia, cerebral hypoperfusion and cardiac arrest. Reports of severe complications related to improper positioning of patients during high levels of spinal or epidural anesthesia have spanned the last six decades.
Myocardial Work
The significant decrease in myocardial work is due primarily to threee factors: Decrease in HR (heart rate), decrease in arterial/total peripheral resistance (afterload), and decrease in stroke volume of the left ventricle secondary to the decreased preload.
Supplemental Oxygen
The purpose of the supplemental oxygen is to assure that tissue oxygenation is maintained , despite decreases in CO and periperal blood low.
Neuraxial anesthesia decreases afterload by producing arterial vasodilation. This vasodilation however is not equivalent in all vascular beds. For instance, muscle and skin blood flow may be decreased by sympathectomy, whereas the total blood flow to the same extremity may be quadrupled. Additionally, the extent to which afterload is decreased by sympathetic denervation varies considerably from one patient to another.
The effectiveness of this reflex vasoconstriction in maintaining normotension is a function of the extent of the sympathetic block. If, for instance, sympathetic block reaches the fourth thoracic dermatome (T4) or higher, the intact upper limb vasculature may contribute only 5% of the total cardiac output. Even maximal vasoconstriction will be insuffiecient to compensate for the profound arterial vasodilation in the rest of the body.
Cardiac Function
Importantly, bradycardia during high (thoracic) levels of spinal or epidural anesthesia is due to two main factors: denervation of preganglionic cardiac accelerator fibers (T1-4) and diminished venous return to the right ventricle because of decreases in preload.
Cardiac Output
The extent of CO decrease is also a function of the degree of sympathetic denervation.
Conversely, assumption of an even slight head-up position during neuraxial anesthesia with high levels of sympathetic denervation (..) may have catastrophic consequences such as profound bradycardia, cerebral hypoperfusion and cardiac arrest. Reports of severe complications related to improper positioning of patients during high levels of spinal or epidural anesthesia have spanned the last six decades.
Myocardial Work
The significant decrease in myocardial work is due primarily to threee factors: Decrease in HR (heart rate), decrease in arterial/total peripheral resistance (afterload), and decrease in stroke volume of the left ventricle secondary to the decreased preload.
Supplemental Oxygen
The purpose of the supplemental oxygen is to assure that tissue oxygenation is maintained , despite decreases in CO and periperal blood low.
Complications in Anesthesiology
By Emilio B. Lobato, Nikolaus Gravenstein, Robert R. Kirby
Contributor Emilio B. Lobato, Nikolaus Gravenstein, Robert R. Kirby
Edition: 3, illustrated
Published by Lippincott Williams & Wilkins, 2007
ISBN 0781782635, 9780781782630
Shivering - a normal response during fever is eliminated by sympathectomy
During fever pyrogen is released from leucocytes and this agent causes the disturbed thermoregualtion (Atkins, 1960). For this response to occur, an intact efferent sympathetic system is required because fever can be markedly reduced by bilateral sympathectomy in the cat (Pinkston, 1935). In man, pyrogen seems to act above the level of the 5th cervical spinal cord segment; for a patient with a lesion at that level the intravennours administration of pyrogen produced shivering in normally innervated muscles only and no alteration in hand blood flow was seen (Cooper at al., 1964)
The Autonomic Nervous System: An Introduction to Basic and Clinical Concepts
By Otto Appenzeller, Emilio Oribe
Edition: 5, illustrated
Published by Elsevier Health Sciences, 1997
ISBN 0444827617, 9780444827616
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