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10/5/2009
Margaret Biancofiori, SRNA
Rosalind Franklin University of Medicine and Science
October 4, 2009
What is P.O.T.S.?
 Chronic form of orthostatic intolerance syndrome
 Primarily affects younger women -but not exclusively
(4:1)
 Definition:
 Symptoms of orthostatic intolerance accompanied by a
heart rate increase of at least 30BPM or a rate that exceeds
120 BMP that occurs within the first 10 min. of standing or
head –up tilt
Signs and symptoms of
OI/P.O.T.S.
 Dramatic increase in HR associated with one or more of
the following:
 Light-headedness
 Clouded thoughts
 Blurring/dimming vision
 Anxiety
 Shoulder / Neck pain
 Nausea
 Diaphoresis
 Frank syncope
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Defining Orthostatic
Intolerance
 Provocation of symptoms upon standing and relief of symptoms
when becoming supine-although symptoms can present without
change in position
 OI is synonymous with:
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Idiopathic orthostatic intolerance
Postural orthostatic tachycardia syndrome
Orthostatic tachycardia syndrome
Sympathetic orthostatic hypotension
Hyperadrenergic postural hypotension
Idiopathic hypovolemia
Mitral valve prolapse syndrome
Soldier’s Heart
Irritable Heart
Chronic Fatigue Syndrome
Orthostatic Intolerance
 According to the Vanderbilt Autonomic Dysfunction
Center at Vanderbilt University Medical Center, Other
than essential hypertension, OI is the most common
disorder of blood pressure regulation. OI is also the most
frequently encountered dysautonomia.
 Nearly 500,000 Americans are affected ranging from
mild to debilitating.
 Diabetes is one of the most significant secondary causes
of Orthostatic hypotension
Pathophysiology
 Poorly characterized
 Pts often have elevated levels of catecholamines with
standing (“hyperadrenergic state”)
 Baseline hypovolemia
 Excessive pooling of blood in lower extremities with
standing w/ an exaggerated orthostatic hypovolemia
 Evidence of lower extremity sympathetic denervation
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Pathophysiology2 Sub-types
1) Partial Dysautonomia- 90% of cases
Presents as tachycardia w/light-headedness,nausea, chronic
fatigue, dependent edema, acrocyanosis
2)Hyperadrenergic (<10%)
Manifests as increased serum Norepinepherine (>600pg/ml)
(Normal 150-550 pg/ml),tremulousness, anxiety and
exaggerated response to B-adrenergic stimulation
Diagnosis
 Tilt table test
 Standard method-reverse T-burg tilt of at least 60 degrees
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Optimal duration is 40 minutes with periodic measurements of HR and
BP. Test is concluded upon syncopal episode
Isoproterenol maybe injected IV to test for hypersensitivityof betaadrenergic receptors.
People who have POTS with beta-receptor supersensitivity and a
hyperadrenergic state will have an exacerbation of symptoms from
isoproterenol. Otherdrugs used in place of isoproterenol include
nitroglycerin, edrophonium,adenosine triphosphate, ephedrine and
nitroprusside
 Symptoms of orthostatic intolerance accompaniedbya heart rate
increase of at least 30BPM or a rate that exceeds 120 BMP that
occurs within the first 10 min. of standing or head –up tilt
Tilt Table Test
www.nymc.edu/fhp/
centers/syncope/
HUT%20and...ation.htm
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Diagnosis
 Catecholamine level and metabolite measurements via
blood test or 24 hr urine collection
 Bowel motility studies
 Cold pressor test
 MRI to detect brain lesions
 EMG/nerve conduction studies
Treatments-Pharmacologic
 MIDODRINE: (Proamatine)
 Alpha-1 agonist
 Pro-drug ; converted to active compound desglymidodrine
 Parent compound peaks 30 min. after PO dose
 Active compound peaks 1-2 hrs after PO dose
 Elimination T ½ is 3-4 hours
 Pro-drug and metabolite excreted in urine
 Dose 2.5-10 mg 3x day
 MOA: Increases BP via increase in peripheral vascular resistance
 No direct effect on heart-may see reflex decrease in HR
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Manypatients take Beta blockers to counteract reflex tachycardia
associated with OI/OH
Treatments (cont’d)
 Midodrine
 Side effects: piloerection, pruritus, tingling of scalp
Supine hypertension is a side effect of greater concern
with BPs of > 180/110 mmHg in 25% of pts taking Midodrine 3x
daily
Pts are advised to take evening dose 4hrs before bedtime to
decrease nocturnal supine hypertension
Pts are also advised to elevate the head of the bed 30 degrees to
further decrease the possibility of supine hypertension
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Treatments
 Beta-blocker therapy:
 Propranolol 20 mg 2x day
 Fludrocortisone (Florinef)
 0.1 -0.4mg daily
 Potent mineralocorticoid properties
 Causes sodium/water retention
 May need to replace potassium – check pts potassium level
DIET:
Increased fluid consumption along with increased sodium
potassium intake is recommended to maintain volume/BP.
Compression stockings are sometimes indicated.
Anesthetic Implications
 Thorough preoperative H&P to determine the major
pathophysiologic component
 Correction of hypovolemia-HYDRATE
 Adequate pre-op anxiolysis to decrease sympathetic
response/tachycardia
 A-line and/or CVP
 Be mindful that use of alpha-1 agonists such as
phenylepherine may be useful to treat hypotension but that
lower extremity sympathetic denervation may cause upregulation of peripheral alpha-1 receptors leading to receptor
hypersensitivity
Anesthetic Implications
 Supine hypertension:
 Many OI patients exhibit hypertension when supine
 Thought to be due to lack of baroreceptor control and/or
hypersensitivity of partially denervated postsynaptic
adrenoreceptors to NE
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According to a study by Chaimberg and Travis, pts taking
Midodrine may exhibit severe hypertension when supine. They
advise patients to omit their midodrine on the day of surgeryespecially of prolonged post-op bedrest is anticipated.
Reverse Trendellenburg as a treatment if possible-it’s effect is
quick and readily reversible
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Anesthetic ImplicationsLabor and Delivery
Goals:
Avoid stress of labor and subsequent tachycardic response
 P.O.T.S. is associated with hemodynamic instability
 This HD instability is worsened by labor and delivery
 HD instability can be lessened w/ early pain control
Neuraxial blockade may need to be in lateral
decubitus position as sitting may exacerbate P.O.T.S.
symptoms
Monitor BP q 1-2 minutes
Anesthetic ImplicationsLabor and Delivery
 2nd stage of labor is greatest concern
 Management varies with patient’s response to Valsalva
maneuver
 P.O.T.S. pts have larger decrease in BP in early phase of Valsalva
and larger overshoot of BP and HR in late phase
 Slower return to baseline
 Decreased thoracic blood flow
 Significant increase in pelvic vascular resistance during Valsalva
found in non-pregnant patients with increase in syncopal events
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No studies yet in pregnant patients but combination of the HD changes
is thought to greatlycompromise uteroplacental blood flow
Anesthetic ImplicationsLabor and Delivery
 Recommendations from a study conducted by McEvoy, Low
and Hebbar;2007:
 A-line if large HD changes noted in 2nd stage of labor
 If variations sustained and baseline values not reached before
next contraction -or-
 If baby not tolerating pushing Restrict Valsalva maneuvers and proceed with instrumental or
operative delivery
If C-section delivery with neuraxial blockade:
Epidural is method of choice : Ability to incrementally dose epidural
produces gradual change in HD rather than the suddendecrease in
systemic vascular resistance and subsequent increase in
baroreceptor activated sympathetic activity observed with SAB.
(Corbett, et.al.;2006)
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Anesthetic ImplicationsLabor and Delivery
 HTN in P.O.T.S. pts with hyperadrenergic form:
 Labetalol is ok but unpredictable- McEvoy, et.al.,
recommend smaller doses, titrated to effect
 Hypotension associated with neuraxial blockade
 Phenylepherine drug of choice in pts with hyperadrenergic
form of P.O.T.s. – thought to be more beneficial to increase
BP via vasoconstrictive , alpha-1 response rather than
increase in HR
 PRE-HYDRATE
Team approach with anesthesia, obstetrics and neurology and
early consultation is recommened in parturients with P.O.T.S.
Outlook
 More research needed-
 At the time of the study by Corbett, et.al. , only two studies had previously been reported on
epidural management for patients undergoing cesarean section.
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 Places conducting research:
 Vanderbilt Autonomic Dysfunction Center
Nashville, TN
www.mc.vanderbilt.edu
 National Dysautonomia Research Foundation
Red Wing, MN
www.ndrf.org
 Center for Hypotension
New York Medical College
Valhalla, New York
www.nymc.edu/fhp/centers/syncope/J_Stewart.htm
References
 Chaimberg K,Travis K. Supine Hypertension During GeneralAnesthesia in a Patient Taking
Midodrine: Anesthesia&Analgesia 2002;95: 1196-1197. http://www.anesthesiaanalgesia.org/cgi/content/full/95/5/1196 Accessed July 2,2009.
 Corbett WL, ReiterCM,Schultz JR, Kanter RJ, Habib AS.Anaesthetic management of a
parturient with the postural orthostatic tachycardia syndrome: a case report: British Journal
ofAnaesthesia 2006;97: 196-199. http://bja.oxfordjournals.org/cgi/content/full/97/2/196
Accessed December 29, 2008.
 McEvoy MD, Low PA, Hebbar L. PosturalOrthostatic Tachycardia Syndrome: Anesthetic
Implications in theObstetric Patient: Anesthesia&Analgesia 2007;104: 166-167.
http://anesthesia-analgesia.org/cgi/content/full/104/1/166 Accessed July 20, 2009.
 Mchaourab A, Mazzeo A, May J, Pagel P. PerioperativeConsiderations in a Patient with
Orthostatic IntoleranceSyndrome; Anesthesiology 2000;93: 571-573.
http://journals.1ww.com/anesthesiology/pages/articleviewer.aspx?year=2000&issue=0800...
Accessed December 29, 2008.
 Vanderbilt Autonomic Dysfunction CenterWebsite.
http://www.mc.vanderbilt.edu/root/vumc.php?site=adc&doc=4783 Accessed September 29,
2009.
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