This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by McEvoy, M. D. Articles by Hebbar, L. Search for Related Content PubMed PubMed Citation Articles by McEvoy, M. D. Articles by Hebbar, L. Related Collections Obstetrics Physiology

---

OBSTETRIC ANESTHESIA

Postural Orthostatic Tachycardia Syndrome: Anesthetic Implications in the Obstetric Patient

Matthew D. McEvoy, MD^*, Phillip A. Low, MD, and Latha Hebbar, MD^*

From the *Department of Anesthesiology and Perioperative Medicine, Medical University of South Carolina, Charleston, South Carolina; and Department of Neurology, Mayo Clinic, Rochester, Minnesota.

	Abstract

Top Abstract Introduction CASE REPORT REFERENCES

 
We report the anesthetic management of a parturient with postural orthostatic tachycardia syndrome. This syndrome is associated with hemodynamic instability, which can be worsened by the physiology of labor and delivery. We discuss anesthetic concerns with this disease in the parturient and suggest approaches for management of this disease.

	Introduction

Top Abstract Introduction CASE REPORT REFERENCES

 
Postural orthostatic tachycardia syndrome (POTS) is an autonomic disorder of orthostatic intolerance with two subtypes based on pathophysiology. The first type, partial dysautonomia form (90% of cases), manifests as tachycardia in the upright position with symptoms of orthostatic intolerance such as lightheadedness, nausea, chronic fatigue, dependent edema, and acrocyanosis. The second type, hyperadrenergic form (<10%), manifests as increased serum norepinephrine levels (>600 pg/mL), tremulousness, anxiety, and an exaggerated response to ß-adrenergic stimulation (1). Diagnostic criteria include an increase in heart rate (HR) of 30 bpm or an absolute HR 120 bpm within 10 min of standing or head-up tilt, symptoms of orthostatic intolerance, and absence of known cause of autonomic neuropathy. Immune-mediated and genetic abnormalities are proposed in the pathogenesis of POTS (2,3), a subgroup of orthostatic intolerance reported in 500,000 patients in the United States (1). POTS typically occurs between the ages of 15 and 50 yr, predominantly in young females (female: male 5:1) (1,4,5). Although Glatter et al. (6) recently reported two cases of parturients with POTS, this is the first case report to discuss the anesthetic management and focuses on the peripartum management of POTS in a parturient with symptoms of the partial dysautonomic form manifested as severe orthostatic intolerance, chronic fatigue, lightheadedness, chest pain, acrocyanosis, along with extreme fluctuations in arterial blood pressure (BP) and HR.

	CASE REPORT

Top Abstract Introduction CASE REPORT REFERENCES

 
An 18-yr-old woman gravida 2, para 1 presented in active labor at 36-wk gestation with a diagnosis of pregnancy-induced hypertension. Her medical history was significant for POTS and the patient reported a near-cardiac arrest during her first labor and delivery at another hospital. Medical records from that incident were not obtainable and the patient stated that she had not received an epidural for her labor. The patient’s medications included fludrocotisone for the orthostatic symptoms and propranolol 10 mg t.i.d for HR control.

A right radial arterial line was placed, which revealed beat-to-beat BP fluctuations from 104/52 to 184/102 in the semi-recumbent position. After a 1500 mL bolus of lactated Ringer’s solution, the BP stabilized with beat-to-beat variations of 140/79 to 161/95 and HR within the range of 71–89 in the semi-recumbent position. At a cervical dilation of 3 cm, with the patient in the sitting position, an epidural catheter was placed at the L3–4 interspace and dosed with 8 mL of bupivacaine 0.125% with fentanyl 33 mcg in 2–3 mL aliquots over 20 min, establishing a T9–10 level of analgesia. A continuous infusion of bupivacaine 0.1% with fentanyl 2 mcg/mL was administered at 14mL/h. Maternal vital signs and fetal heart tones were monitored and remained unchanged from the postlactated Ringer’s solution bolus variables.

During the course of the epidural, which lasted approximately 2 h, the patient received a crystalloid infusion at 100 mL/h. After augmentation with pitocin, an assisted forceps delivery was performed in order to diminish Valsalva maneuvers by the mother and to prevent hemodynamic fluctuation. Her estimated blood loss was 400 mL. There was no change in the immediate postpartum maternal HR and BP. The baby tolerated labor well with Apgar scores of 6 and 8 at 1 and 5 min, respectively. A total of 1750 mL of crystalloid was administered from the initial bolus to delivery.

Preventing, monitoring, and treating hemodynamic instability may present unique challenges in the parturient with POTS. Hemodynamic instability can likely be prevented through early pain control. In patients with the partial dysautonomic form of POTS, neuraxial blockage may need to be placed in the lateral decubitus position if the patient develops symptoms of orthostatic intolerance in the sitting position. In patients with the hyperadrenergic variety of POTS, it is beneficial to establish analgesia early in labor to avoid excessive ß-adrenergic hyperactivity. Frequent hemodynamic monitoring (every 1–2 min) is suggested during position changes (including epidural placement) to monitor and minimize hemodynamic instability.

Management of the second stage of labor in patients with POTS requires the greatest vigilance, and will vary depending on the response to a Valsalva maneuver. In patients with POTS when compared with controls, there is a larger decrease in BP during the early phases of Valsalva, with a subsequently larger overshoot of BP and HR in the late phases, showing an overall greater hemodynamic instability and slower return to baseline values (7). Furthermore, there is a variable change in regional blood flow and vascular resistance, with thoracic blood flow decreasing to a larger degree in patients with POTS than in controls. This contributes to the observed increase in hypotension seen in these patients. Of note, there is a significant increase in pelvic vascular resistance in POTS patients versus controls during Valsalva (7). Although this has not been studied in parturients, this finding in nonpregnant patients at least raises the concern that pushing (Valsalva) during the second stage of labor in a parturient with POTS might decrease BP, while increasing vascular resistance in the pelvic blood vessels. Furthermore, Valsalva maneuvers in these patients may result in syncopal events (7). Taken together, these hemodynamic changes could greatly compromise uteroplacental blood flow. Glatter et al. reported the successful management of two parturients with POTS via cesarean delivery under epidural anesthesia, which minimized the aforementioned concerns regarding Valsalva. Because the details of our patient’s obstetric history were unknown, we placed an arterial line for hemodynamic monitoring and avoided the Valsalva maneuver by opting for a forceps-assisted vaginal delivery.

We recommend monitoring hemodynamics at frequent intervals during the second phase of labor. If large hemodynamic variations are encountered, an arterial line should be considered. If these variations are sustained with baseline hemodynamic values not reached before the next contraction, or if the baby does not tolerate pushing, then Valsalva maneuvers should be restricted and instrumental or operative delivery should be performed.

With respect to treating hemodynamic changes in the obstetric patient, phenylephrine is considered by some to be the first-line therapy for management of hypotension associated with neuraxial blockade (8). The choice of this pressor is particularly appropriate in patients with the hyperadrenergic form of POTS, as it may be more beneficial to increase BP via a vasoconstrictive 1 response rather than by increases in HR (9). In the hypertensive obstetric patient, labetalol can be used for HR and BP control (10). However, in an obstetric hyperadrenergic POTS patient, the response to mixed and ß effects of labetalol may be unpredictable and therefore if this drug is chosen, smaller doses should be titrated (11).

The incidence of POTS with its complex autonomic pathophysiology occurs most frequently in females of child-bearing age. Management of parturients with POTS requires a team approach by obstetricians, anesthesiologists, and neurologists to provide optimal clinical care for maternal and fetal safety, and early consultation is recommended.

	Footnotes

 
Accepted for publication September 12, 2006.

Address for correspondence and reprint requests to Matthew D. McEvoy, MD, Department of Anesthesiology and Perioperative Medicine, Medical University of South Carolina, 165 Ashley Ave., CH 525, Charleston, SC 29425, 843-792-2322, 843-792-2726. Address e-mail to mcevoymd{at}musc.edu.

	REFERENCES

Top Abstract Introduction CASE REPORT REFERENCES

 

1. Kanjwal Y, Kosinski D, Grubb BP. The postural orthostatic syndrome: definitions, diagnosis and management. Pacing Clin Electrophysiol 2003;26:1747–57.[Medline]
2. Schondorf R, Low P. Idiopathic postural orthostatic tachycardia syndrome: an attenuated form of acute dysautonomia? Neurology 1993;43:132–7.[Abstract/Free Full Text]
3. Shannon JR, Flatten NL, Jordan J, et al. Orthostatic intolerance and tachycardia associated with nor-epinephrine-transporter deficiency. N Engl J Med 2000;342:541–9.[Abstract/Free Full Text]
4. Benrud-Larson LM, Dewar MS, Sandroni P, et al. Quality of life in patients with postural tachycardia syndrome. Mayo Clin Proc 2002;277:531–7.
5. Robertson D. The epidemic of orthostatic tachycardia and orthostatic intolerance. Am J Med Sci 1999;317:75–7.[Web of Science][Medline]
6. Glatter KA, Tuteja D, Chiamvimonvat N, et al. Pregnancy in postural orthostatic tachycardia syndrome. Pacing Clin Electrophysiol 2005;28:591–3.[Medline]
7. Stewart JM, Medow MS, Montgomery LD, et al. Splanchnic hyperemia and hypervolemia during Valsalva maneuver in postural tachycardia syndrome. Am J Physiol Heart Circ Physiol 2005;289:H1951–H1959.[Abstract/Free Full Text]
8. Lee A, Ngan Kee WD, Gin T. A quantitative, systematic review of randomized controlled trials of ephedrine versus phenylephrine for the management of hypotension during spinal anesthesia for cesarean delivery. Anesth Analg 2002;94:920–6.[Abstract/Free Full Text]
9. Stewart JM, Munoz J, Weldon A. Clinical and physiological effects of an acute -1 adrenergic agonist and a ß-1 adrenergic antagonist in chronic orthostatic intolerance. Circulation 2002;106:2946–54.
10. Vigil-De Gracia P, Lasso M, Ruiz E, et al; for the HYLA treatment study. Severe hypertension in pregnancy: hydralazine or labetalol. A randomized clinical trial. Eur J Obstet Gynecol Reprod Biol 2006;128:157–62.[Web of Science][Medline]
11. Grubb BP. Syncope resulting from autonomic insufficiency syndromes associated with orthostatic intolerance. Med Clin North Am 2001;85:457–72.[Web of Science][Medline]

This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a colleague Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via Google Scholar Google Scholar Articles by McEvoy, M. D. Articles by Hebbar, L. Search for Related Content PubMed PubMed Citation Articles by McEvoy, M. D. Articles by Hebbar, L. Related Collections Obstetrics Physiology