Anaesthesia for appendicectomy in a patient with postural orthostatic tachycardia syndrome
Provisional Fellow (Research), Department of Anaesthesia, The Royal Melbourne Hospital
Belinda Schramm, M.B., B.S., F.A.N.Z.C.A.
Consultant Anaesthetist, Department of Anaesthesia, The Royal Melbourne Hospital
Both authors are salaried staff of the Royal Melbourne Hospital. No financial support was
sought for this case report and there is no financial interest to declare.
Department of Anaesthesia and Pain Management
Anaesthesia for appendicectomy in a patient with postural orthostatic tachycardia syndrome
Postural orthostatic tachycardia syndrome is a poorly understood disorder of the autonomic
nervous system. The syndrome is defined by the development of orthostatic intolerance
associated with a heart rate increment 30 beats per minute or increase in heart rate to
120 beats per minute within the first 10 minutes of standing without hypotension.
Symptoms of orthostatic intolerance are a combination of cerebral hypoperfusion and
sympathetic overactivation. This report describes the anaesthetic management of a 41 year
old female patient with postural orthostatic tachycardia syndrome presenting for emergency
appendicectomy. Management focused upon ensuring stable haemodynamics during
surgery. The patient had an uneventful anaesthetic for appendicectomy and was discharged
Postural orthostatic tachycardia syndrome (POTS) is a rare and perplexing disorder of the
autonomic nervous system that is characterised by orthostatic intolerance. A distinguishing
feature of the condition is that, on standing, blood pressure is maintained or only falls
minimally, whilst heart rate increases dramatically. Patients usually complain of a myriad
of symptoms (Table 1). Although the cause of POTS is unknown, several pathophysiologic
models have been described including neuropathic, hyperadrenergic, genetic and
hypovolaemic dysfunction, and impaired cerebral autoregulation.
Here we report the case of a 41 year old female with POTS presenting out of hours for an
emergency appendicectomy, and describe the pathophysiology and anaesthetic implications
A 41 year old female patient presented with a two day history of nausea and vomiting,
chills and abdominal pain, and was scheduled for emergent laparoscopic appendicectomy in
May 2009. She weighed 62 kg and was 170 cm tall (BMI=21.5). In 2007 she was
diagnosed with POTS using invasive tilt testing and suffered with recurrent palpitations (2-
3 times weekly) and syncopal episodes (1-2 episodes fortnightly). She had developed these
disabling symptoms in 2001 and had undergone extensive cardiac evaluation with five
cardiac electrophysiology studies including two attempted radiofrequency ablations.
In 2007, the patient had shoulder reconstruction in the sitting position under general
anaesthesia with interscalene nerve block. During this surgery, she had several episodes of
hypotension which required aggressive intravenous fluid therapy, pressor support and
repositioning. In the recovery room, she developed florid pulmonary oedema necessitating
urgent intubation and transfer to another hospital for intensive care management.
Transthoracic echocardiography at this time showed severe impairment of left ventricular
systolic function with an ejection fraction of 15% due to anteroseptal hypokinesis and
severe hypokinesis of other wall regions. She improved dramatically and was extubated
within 12 hours following a large diuresis. Repeat transthoracic echocardiogram 48 hours
later showed almost complete resolution of her left ventricular dysfunction. The valves
appeared structurally normal, with trivial aortic regurgitation, trivial mitral regurgitation,
Her usual medications included dihydroergotamine mesylate (15 mg t.d.s.), fludrocortisone
(100 mcg o.d.), atenolol (25 mg o.d.), and sertraline (75 mg o.d.) with mersyndol forte
(paracetamol 450 mg, codeine 30 mg, doxylamine 5 mg) and temazepam (10 mg) taken
Prior to presentation she was nauseated and vomiting for two days, with decreased oral
intake. In the emergency department, intravenous access was obtained and the patient
rehydrated with 2L of normal saline over approximately 5 hours.
Upon arrival to theatre, the patient appeared extremely anxious, with an unremarkable
cardiorespiratory examination. The pre-operative supine blood pressure (BP) was 155/65
mmHg and heart rate (HR) 74 beats per minute (beats.min-1).
The patient was given midazolam, 1 mg i.v., and 500 mL compound sodium lactate, after
which a radial arterial line was inserted. Central venous access was obtained through the
right internal jugular vein with ultrasound guidance whilst supine. The opening central
venous pressure was 10 mmHg. Automated pneumatic compression stockings were applied
to both lower limbs. In the operating theatre, standard monitoring was applied, in addition
to invasive central venous and arterial pressure monitoring. After preoxygenation,
anaesthesia was induced with fentanyl (100 mcg), propofol (150 mg), and suxamethonium
(100 mg) and the trachea intubated with cricoid pressure maintained. Post-induction BP
was 110/55 mmHg and the HR 78 beats.min-1.
Anaesthesia was maintained with sevoflurane (end-tidal 2.2-2.3%) in an air/oxygen
mixture. Intraoperative analgesia included fentanyl (100 mcg), morphine (6 mg), parecoxib
(40 mg), and paracetamol (1 gm i.v.). Tidal volume and respiratory rate was titrated to end-
tidal CO2 and core temperature was maintained between 36.2 and 36.0°C with a forced air
warmer. Intraoperatively, the patient required four (50 mcg) boluses of phenylephrine to
maintain her blood pressure in the normal range and received in total 1500 ml of compound
sodium lactate. Haemodynamic parameters remained unremarkable during anaesthesia and
in the recovery room with HR and BP values ranged between 56-84 beats.min-1 and 108/55
to 155/65 mmHg, respectively. Intraoperative central venous pressure (CVP) ranged
Post-operatively the patient was transferred to the high dependency unit and remained
stable until her discharge 48 hours after presentation. Informed consent was obtained from
the patient prior to writing this report.
POTS is a poorly understood disorder of the autonomic nervous system which was named
and identified by Schondorf and Low in 1993.1 A unique feature of POTS, unlike many
forms of syncope, is that the arterial blood pressure is maintained or falls minimally whilst
heart rate increases dramatically.2 POTS is defined as orthostatic intolerance associated
with a heart rate increase of 30 beats.min-1 (or HR that exceeds 120 beats.min-1) that occurs
within the first 10 minutes of standing or upright tilt, not associated with other chronic
debilitating conditions such as prolonged bed rest or the use of medications known to
The symptoms of POTS are non-specific and a variety of alternative names highlight the
diversity of opinion about this perplexing disorder. These include mitral valve prolapse
syndrome,4 idiopathic hypovolaemia,5 hyperadrenergic syndrome6 and more recently in the
lay press and world wide web "yellow wiggle syndrome."7 POTS is a disorder of unknown
aetiology, and several pathophysiologic models have been described, including
neuropathic, hyperadrenergic, genetic and hypovolaemic dysfunction and impaired cerebral
autoregulation. Indeed POTS may be regarded as a heterogenous syndrome with several
subtypes, including neuropathic POTS, hyperadrenergic POTS, and POTS with
Orthostatic symptoms may be aggravated by heat or exercise, and worse at the time of
menses.9 Symptoms are predominantly syncopal (lightheadedness, dizziness, weakness),
and those of sympathetic overactivity (palpitations, tremulousness, nausea). Commonly
described symptoms are listed in Table 1.
The prevalence of POTS is difficult to establish and there are no accurate epidemiological
studies. Current estimates suggest at least 500,000 patients are affected by the disorder in
the United States alone.3 Symptoms commonly present between the ages of 15 to 50 years
with a female preponderance of five to one.10
The onset of POTS is often abrupt and approximately 50% of patients can recall a viral
prodrome. The condition may often be mistaken for depression or anxiety; indeed these
conditions may also coexist and aggravate the syndrome.3 The clinical presentation of
POTS often overlaps with the chronic fatigue syndrome, and 25-50% of patients with
chronic fatigue syndrome also have POTS.11,12,13,14 An association may also exist between
POTS and joint hypermobility which has been described in some patients with Ehlers-
POTS is often difficult to diagnose, and other confounding illnesses must be excluded. A
detailed history is required to establish the severity of orthostatic intolerance. Twenty-four-
hour blood pressure monitoring coupled with a diary recording daily activity is useful in
documenting the severity of symptoms. A full autonomic system review should be
undertaken to assess the autonomic systems involved and look for an autonomic
neuropathy.8 Routine investigations such as full blood count and electrolytes are usually
normal. A 24-hour urinary sodium is a simple test to clarify that the patient has an adequate
fluid and sodium intake. Plasma catecholamines should be sampled supine and after
standing for 15 minutes; in approximately half of patients standing, the noradrenaline
exceeds 600 picogram/mL, which is considered a hyperadrenergic response.16
Cardiovascular investigations should include a 12-lead electrocardiograph, cardiac rhythm
monitoring to exclude primary cardiac causes of syncope and tilt table testing. In
specialised centres, this can be invasive with placement of an arterial line, plasma sampling
for noradrenaline, and microneurography of the peroneal nerve.2
Pharmacological and non-pharmacological interventions are useful in managing POTS,
however the evidence base for these interventions is poor. Table 2 summarises the various
Patients suffering with POTS have been shown to experience clear limitations in their
quality of life and the condition can affect employment prospects and other important
domains.17 There is limited information available regarding the prognosis of POTS.
Generally, the younger the patient, the better the prognosis.3,18 Approximately 90% of
patients will respond to a combination of non-pharmacological and pharmacological
interventions. After onset of post-viral POTS, 50% of patients recover in two to five
years.3,18 Patients with hyperadrenergic POTS usually require therapy indefinitely.3,18
Information on the anaesthetic implications of POTS is not well elucidated. There are
several case reports detailing the management of the parturient patient,19,20 however to our
knowledge there are no case reports describing the anaesthetic management of the patient
with POTS presenting for emergency general surgery.
The anaesthetic management in this case focused particularly upon ensuring stable
haemodynamics. Despite the previous episode of post-operative left heart failure, it was felt
that ensuring normovolaemia was of paramount importance, considering the patient's poor
oral intake in the two days prior to surgery, third space losses, and the impaired absorption
of dihydroergotamine and fludrocortisone. The patient was fluid resuscitated in the
emergency department with 2 L of normal saline. A further 1.5 L of compound sodium
lactate was given in theatre. With agreement from the surgical team, a planned laparoscopic
approach was abandoned due to the desire to avoid unnecessary tilting of the operating
table, the haemodynamic effects of a pneumoperitoneum, and to expedite the rapid
completion of the surgery. We relied upon invasive arterial blood pressure to closely
monitor arterial pressure. The central venous access provided important information
regarding volume status and allowed administration of vasoactive drugs (phenylephrine and
For the intraoperative treatment of hypotension, alpha-1 adrenoceptor agonists such as
phenylephrine21 and noradrenaline22 may be used to augment vascular tone in patients with
POTS. However, they must be cautiously titrated because in some patients, lower extremity
sympathetic denervation may cause upregulation of peripheral alpha-1 adrenoceptors and
contribute to receptor hypersensitivity. Ephedrine should probably be avoided as it causes
an indirect noradrenaline release and has a weak beta-1 agonist effect, both of which may
At all times, the patient was positioned carefully with gradual and controlled movements to
avoid provoking symptoms and signs of orthostatic intolerance. Automated pneumatic calf
compression stockings were used to promote venous return and ensure adequate preload,
and post-operative intensive care permitted close monitoring of the patient's
1. Schondorf R, Low PA. Idiopathic postural orthostatic tachycardia syndrome: an
attenuated form of acute pandysautonomia? Neurology 1993; 43: 132-7.
2. Vaddadi G, Lambert E, Corcoran SJ, Esler MD. Postural syncope: mechanisms and
management. Medical Journal of Australia 2007; 187(5): 299-304.
3. Grubb BP. Clinician update: Postural tachycardia syndrome. Circulation 2008; 117:
4. Coghlan HC, Phares P, Cowley M, Copley D, James TN. Dysautonomia in mitral valve
prolapse. American Journal of Medicine 1979; 67(2):236-44.
5. Fouad FM, Tadena-Thome L, Bravo EL, Tarazi RC. Idiopathic hypovolemia. Annals of
6. Streeten DH, Anderson G H Jr, Richardson R, Thomas FD. Abnormal orthostatic
changes in blood pressure and heart rate in subjects with intact sympathetic nervous
function: evidence for excessive venous pooling. Journal of Laboratory & Clinical
Wiggle/2006/12/01/1164777768080.html Accessed July 2009.
8. Low PA, Sandroni P, Joyner M, Shen WK. Postural tachycardia syndrome (POTS). J
Cardiovasc Electrophysiol 2009; 20: 352-358.
9. Carew S, Connor MO, et al. A review of postural orthostatic tachycardia syndrome.
10. Low PA, Opfer-Gehrking TL, Textor SC, Benarroch EE, Shen WK, Schondorf R,
Suarez GA, Rummans TA. Postural tachycardia syndrome (POTS). Neurology
11. Freeman R, Komaroff AL. Does the chronic fatigue syndrome involve the autonomic
nervous system? American Journal of Medicine 1997; 102(4):357-64.
12. Hoad A, Spickett G, Elliott J, Newton J. Postural orthostatic tachycardia syndrome is an
under-recognized condition in chronic fatigue syndrome. Q J Med 2008; advance access
13. Jones JF, Nicholson A, et al. Orthostatic instability in a population-based study of
chronic fatigue syndrome. American Journal of Medicine 2005; 118(12):1415.
14. De Lorenzo, F, Hargreaves J, Kakkar VV. Possible relationship between chronic fatigue
and postural tachycardia syndromes. Clinical Autonomic Research 1996; 6(5):263-4.
15. Gazit Y, Nahir AM, Grahame R, Jacob G. Dysautonomia in the joint hypermobility
syndrome. Amer Journ Med 2003; 115(1): 33-40.
16. Thieben MJ, Sandroni P, Sletten DM, Benrud-Larson LM. Postural Orthostatic
Tachycardia Syndrome: The Mayo Clinic Experience; Mayo Clinic Proceedings 2007;
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tachycardia syndrome. Mayo Clinic Proceedings 2002; 77, 6:531.
18. Agarwal AK, Garg R, Ritch A, Sarkar P. Postural orthostatic tachycardia syndrome.
19. Corbett WL, Reiter CM, Schultz JR, Kanter RJ, Habib AS. Anaesthetic management of
a parturient with the postural orthostatic tachycardia syndrome: a case report. British
Journal of Anaesthesia 2006; 97(2):196-9.
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orthostatic tachycardia syndrome. Pacing & Clinical Electrophysiology 2005; 28(6):591-3.
21. Jacob G, Shannon JR, Black B, Biaggioni I, Mosqueda-Garcia R, Robertson RM,
Robertson D: Effects of volume loading and pressor agents in idiopathic orthostatic
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22. Streeten DHP: Pathogenesis of hyperadrenergic orthostatic hypotension: Evidence of
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Table 2: Interventions which may be useful in POTS
Used to increase venous return and decrease venous pooling, but
Aerobic activity and resistance training to augment skeletal muscle pump.23
A potent mineralocorticoid that promotes sodium and fluid retention to expand plasma volume, and sensitizes peripheral alpha adrenergic receptors. Hypokalaemia and peripheral oedema can be problematic.2
An alpha-1 adrenergic agonist (tablet), which acts as a peripheral vasoconstrictor and increases blood pressure.9
Sympatholytic beta-blocker which reduces resting heart rate and heart rate increment during standing. Dose-limiting adverse effects include fatigue and hypotension.8
An acetylcholinesterase inhibitor, which enhances both sympathetic and parasympathetic ganglionic transmission, resulting in enhanced vascular adrenergic tone and exerting a vagotonic effect.9
Selective serotonin reuptake inhibitors tend to be more useful in neurocardiogenic syncope and noradrenergic reuptake inhibitors are somewhat more useful in POTS.3,23
Central sympatholytic agents used to treat patients with refractory hyperadrenergic POTS.9
An ergot alkaloid, used to cause arteriolar vasoconstriction to attenuate the response to upright posture.
A somatostatin analogue, which acts a a potent vasoconstrictor and is used to treat patients with refractory POTS.3,9
Used for blood volume expansion and vasoconstriction.9,23
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