ASN's Mission

ASN leads the fight to prevent, treat, and cure kidney diseases throughout the world by educating health professionals and scientists, advancing research and innovation, communicating new knowledge, and advocating for the highest quality care for patients.

learn more

Contact ASN

1401 H St, NW, Ste 900, Washington, DC 20005

email@asn-online.org

202-640-4660

The Latest on Twitter

Kidney Week

Abstract: PO1145

Acute Severe Symptomatic Hyponatremia in the Post-Partum Period: The Syndrome of Oxytocin-Induced Anti-Diuresis (SOIAD)

Session Information

Category: Fluid, Electrolyte, and Acid-Base Disorders

  • 902 Fluid, Electrolyte, and Acid-Base Disorders: Clinical

Authors

  • Shahzad, Muhammad Asim, Rush University Medical Center, Chicago, Illinois, United States
  • Whittier, William Luke, Rush University Medical Center, Chicago, Illinois, United States
  • Rodby, Roger A., Rush University Medical Center, Chicago, Illinois, United States
Introduction

Oxytocin (OXT) is a neuropeptide used in pregnancy to induce uterine contraction. It is structurally related to vasopressin (AVP) by a difference of only 2 amino acids. While it does not have antidiuretic activity at physiologic levels, it can when administered at pharmacologic doses (>20 mU/min). We present a case of severe symptomatic hyponatremia after receiving oxytocin in the post-partum period.

Case Description

A 31 y/o G1PO woman was admitted with premature membrane rupture at week 38. An IV oxytocin infusion (2mU/min) was started to augment labor. Her serum sNa 6 hrs later was 132 mmol/l (baseline sNa 140). Her delivery was c/b uterine atony and postpartum hemorrhage requiring a bolus of IV oxytocin (10 U over 30 min) followed by infusion at 8 mU/min. The sNa 18 hr later was 118 mmol/l. She reported nausea. Her sOsm was 252 mOsm/kg with UNa of 95 mmol/l and Uosm 880 mOsm/kg consistent with the syndrome of anti-diuresis (SIAD). OXT was suspected and was stopped. 2 hr later, a rapid water diuresis ensued (u vol 150-200 cc/hr, with uOsm 92 mOsm/kg). The sNa 4 and 8 hrs later increased to 124 and 127 respectively. Because of concern for over-correction, she was given DDAVP and D5W. This resulted in a gradual (6-8 mmol/l/24 hr) sNa increase to 140 mmol/l over the next 48 hr (Fig 1).

Discussion

Therapeutic OXT can result in anti-diuresis with water retention. OXT half-life is only 1-6 min and is further reduced during pregnancy. Women are more likely to have severe neurologic sequelae of hyponatremia so it is fortuitous that the half-life of OXT is so short, and discontinuation alone should result in a rapid water diuresis. Still, although acute hyponatremia can usually be safely corrected rapidly, concern over what could have been an increase in sNa of 28 mmol/l over several hrs necessitated a DDAVP clamp to slow correction. She had a complete recovery.
SOIAD can be a severe complication of OXT. Since it can occur rapidly and severely, sNa should be followed closely when patients are on OXT infusion.