RN/DREXEL Home Study Program CE CENTER

CE credit is no longer available for this article. Expired July 2005

Originally posted October 2003

Is it morning sickness—or something worse?

TRISTIN S. CARPENTER, RN, MS

TRISTIN CARPENTER is a nurse case manager for University Health Systems of Eastern Carolina/The Community Care Plan of Eastern Carolina in Greenville, N.C.

KEY WORD: hyperemesis gravidarum, molar pregnancy, electrolyte imbalance, Wernicke's encephalopathy, nausea and vomiting of pregnancy (NVP)

During her pregnancy, the author vomited so much that she had to be hospitalized. Thanks to early diagnosis and treatment of hyperemesis gravidarum, she and her baby had no adverse effects. Here's what you need to know about this potentially dangerous condition.

My joy at becoming pregnant for the first time was rapidly replaced by misery. Although I had little nausea during the initial six weeks of my pregnancy, I was vomiting almost continuously by the seventh. After eight weeks, I'd lost eight pounds. When I stopped urinating because I couldn't keep any fluids down, I was hospitalized. My condition was diagnosed as hyperemesis gravidarum (HG).

Although there's no standard definition of HG, this uncommon but serious condition is generally described as persistent, severe nausea and vomiting during pregnancy that extends beyond the first trimester and can last the entire nine months.^1,2 If untreated, HG can lead to grave consequences, including miscarriage and maternal death.² That's why identifying the condition early on is so important.

Diagnosing HG is not that easy, though. Nausea and vomiting, or morning sickness, are fairly common in pregnancy; so when a pregnant woman complains of them, HG isn't the primary suspect. Even when hyperemesis is acknowledged, some practitioners see it as a psychosomatic problem—a long-held theory that hasn't been supported by research.^3,4

HG is a medical problem that requires prompt and appropriate treatment. Understanding why it occurs, how it presents itself, and how it's managed will help you ensure that your patient and her baby get through this complication of pregnancy without any ill effects.

The complication with unknown causes

HG is a rare condition, occurring in less than 2% of pregnant women.⁵ It's more common in molar pregnancies and in women carrying multiple fetuses.

The symptoms of HG vary in severity from woman to woman and from pregnancy to pregnancy. They can lead to maternal dehydration, weight loss, electrolyte imbalance, and ketosis.^1,2 The fluid loss from vomiting can decrease maternal blood volume, reducing placental blood flow, which can adversely affect fetal growth and oxygenation.^1,2,5

In severe cases, lack of hydration and nutrients can lead to maternal liver and kidney damage; coma; and Wernicke's encephalopathy, a neurological condition caused by thiamine depletion and characterized by memory loss, aphasia, and lack of muscle coordination.⁶ In extreme cases, women with untreated HG may be forced to terminate their pregnancies because of starvation.

We do not know for certain what causes HG or why it develops in some women and not others. It's thought to occur because of sensitivity to the increased levels of hormones that occur during pregnancy, the main ones being estrogen, human chorionic gonadotropin (hCG), and progesterone. Either individually or in combination, these hormones may trigger the excessive nausea and vomiting of HG.²

Supporting this theory, for example, is the fact that some women with HG also had nausea and vomiting when they took oral contraceptives containing high doses of estrogen. The connection between hCG and nausea/vomiting may be even stronger: Levels of this hormone peak during the first trimester, when morning sickness is typically at its worst. And high levels of progesterone probably exacerbate nausea and vomiting by slowing gastric emptying.^1,2,7

Other possible causes of HG include liver congestion (due to the increased workload on the liver during pregnancy), hyperthyroidism (hCG stimulates thyroid function), vitamin B₆ deficiency, and gastrointestinal abnormalities such as Helicobacter pylori infection.^2,5,8 Another theory links HG with a high-fat diet prior to pregnancy.

Distinguishing HG from normal symptoms

Distinguishing between HG and normal nausea and vomiting of pregnancy (NVP) can be difficult. Consider HG if a pregnant woman has nausea and vomiting that is pernicious or continues beyond the 16th week, has signs of dehydration, or continues to lose weight.

Persistent nausea and vomiting. Nausea and vomiting doesn't present in the same way in all women with HG. In some, symptoms develop gradually, progressing over several weeks. In others, they come on suddenly and severely.

Women with typical NVP may feel nausea only at certain times of the day. Vomiting can be triggered by smells or by eating certain foods, and it may occur two to three times a day. In contrast, a patient with HG may vomit as many as 20 times a day, and retch in between. Nausea is usually present throughout the day and is not necessarily triggered by a particular smell or food.

In typical NVP, symptoms usually diminish greatly after 14 to 16 weeks; in HG, they usually linger throughout the pregnancy. In my case, I continued to vomit until my son was born.

Dehydration. This presents the most immediate danger to patients with HG. It can develop rapidly and be quite severe. Signs of dehydration include increased heart rate and body temperature, decreased blood pressure and skin turgor, altered vision, and esophageal and gastric ulcers. The patient may also exhibit neurological changes, such as confusion,^1,2,5 and electrolyte imbalances, particularly hypokalemia, which can result in a fatal arrhythmia.

Weight loss. Even in normal pregnancies, some weight loss in the first trimester (attributable to morning sickness) is OK. However, suspect HG if a patient loses 5% or more of prepregnancy weight during the first trimester.⁵ Weight loss that continues into the second trimester is not normal either. I lost 25 pounds, or 12% of my prepregnancy weight, in my first 10 weeks.

Laboratory findings may also clue you in to HG. Be alert for a rise in hematocrit, blood urea nitrogen concentration, urine specific gravity, bilirubin levels, or liver enzymes, such as aspartate aminotransferase (AST) and alanine aminotransferase (ALT);^2,9 ketosis and ketonuria; and other signs of metabolic acidosis. Also watch for thiamine and vitamin B₆ deficiency.

For HG to be diagnosed, other conditions that can cause nausea and vomiting must be ruled out. These include diabetes mellitus, appendicitis, thyroid imbalances, cholecystitis, and pyelonephritis.

A treatment triad: Fluids, food, drugs

Physicians usually recommend a diet of bananas, apples, rice, and toast and other dietary changes to help curb nausea and vomiting. However, if the symptoms continue, the treatment becomes more aggressive, with medications to relieve nausea and prevent vomiting, fluids to correct dehydration and electrolyte imbalances, and nutrition therapy.^7,10

Medication. Drugs used in the management of HG include selective serotonin receptor antagonists, such as ondansetron HCl (Zofran) and granisetron HCl (Kytril); H₂-receptor antagonists, such as ranitidine HCl (Zantac), cimetidine (Tagamet), and famotidine (Pepcid); phenothiazines, such as prochlorperazine edisylate (Compazine) and promethazine HCl (Phenergan); metoclopramide (Reglan); and corticosteroids.^2,5,11,12 Low doses of chlorpromazine HCl (Thorazine), a psychotropic agent, can relieve nausea by acting centrally in the brain to stop the vomiting and also by drying up excessive oral secretions.

Many of the medications used to treat HG can be administered as a rectal suppository, rather than by mouth.¹³ In severe cases, the subcutaneous route may be used, instead. Subcutaneous metoclopramide therapy, for example, is a safe and effective treatment for hyperemesis.¹³

Because most of the drugs used to treat HG have not been studied officially in pregnant women, we don't have clinical proof that they're safe for the fetus. However, they've been used for years to treat nausea and vomiting in pregnancy, without adverse effects.

Homeopathic remedies such as motion sickness bracelets, cinnamon and ginger candy, and lemon in water may also help control severe nausea and vomiting during pregnancy. Hypnosis, acupressure, and acupuncture may help, too.^2,5

Intravenous fluid replacement. IV fluids are necessary if oral hydration is inadequate or not tolerated, and this may require a 24- to 48-hour hospital stay. During that time, nothing is given by mouth in order to allow the GI system some "recovery" time from repeated vomiting.¹⁰

Fluid replacement is frequently achieved with lactated Ringer's solution or D₅LR with 20 mEq KCl/L.¹¹ The potassium is given to prevent the hypokalemia that can develop after prolonged vomiting, and is supplemented based on the patient's serum levels. After rehydration, some women will be able to manage their nausea and vomiting with dietary changes and/or medication.

Nutrition therapy. In addition to medications and IV therapy, some HG patients will require tube feedings, as I did, and will need to remain in the hospital until an effective nutrition regimen is established. Nasoduodenal tubes are preferred over nasogastric tubes because they deliver the feeding into the small intestine rather than the stomach. However, if the patient's esophagus and throat are sore and/or ulcerated from continuous vomiting, a tube can make matters worse. Also, because the HG patient's problem is keeping food down, not swallowing it, feeding through a tube could exacerbate the vomiting.

When tube feeding is unsuccessful, parenteral nutrition, through a central line or a peripherally inserted central catheter (PICC), may be the only other option. I opted for the PICC because the risk of infection would be lower than with a centrally inserted catheter. Because any central catheter can become infected, clogged, or dislodged, parenteral nutrition should be a last resort.⁵

Living with HG: Tough but possible

Once my caloric needs were established and total parenteral nutrition (TPN) was started, I was sent home, where I received home health and infusion services for the remainder of my pregnancy. My condition had stabilized. I was receiving ondansetron 8 mg once or twice a day PO; famotidine, which was added to the TPN solution; magnesium hydroxide (Mylanta) every night; and calcium carbonate (Tums) throughout the day.

During the month following my discharge, I needed the TPN, a liter of IV fluid, and 1 – 2 gm of IV calcium every day. When I was able to drink a liter of fluid a day, the IV fluid was discontinued, but I still needed the TPN as well as the calcium.

In the meantime, I struggled with other HG-related problems. One was ptyalism,¹⁴ or excessive salivation. I needed to carry a spit cup everywhere I went. And, when I had a urinary tract infection, it took me nearly four weeks to complete a 10-day course of antibiotics because keeping pills down was sometimes impossible.

At around 20 weeks, my symptoms diminished and I was vomiting only two to three times a night. Steadily, I was able to eat more and more until I was consistently keeping down a minimum of two cans of Ensure and some cheese and crackers every day. Finally, at 33 weeks, I reached my prepregnancy weight.

During my 35th week, the TPN was discontinued, but I was still vomiting a couple of times a week. Just before my healthy 8 lb, 1 oz son was born at 39 weeks, I weighed 14 pounds more than I had weighed before becoming pregnant.

HG is physically and emotionally exhausting and stressful for a pregnant woman and her family. Although the treatment and education you provide will help keep her symptoms in check, your understanding and compassion will go further than you know in easing her burden.

REFERENCES

1. Attard, C. L., Kohli, M. A., et al. (2002). The burden of illness of severe nausea and vomiting of pregnancy in the United States. Am J Obstet Gynecol 186(5, part 2), S220.

2. Snell, L. H., Haughey, B. P., et al. (1998). Metabolic crisis: Hyperemesis gravidarum. J Perinat Neonatal Nurs, 12(2), 26.

3. Buckwalter, J. G., & Simpson, S. W. (2002). Psychological factors in the etiology and treatment of severe nausea and vomiting in pregnancy. Am J Obstet Gynecol 186(5, part 2), S210.

4. Simpson, S. W., Goodwin, T. M., et al. (2001). Psychological factors and hyperemesis gravidarum. J Women's Health Gend Based Med, 10(5), 471.

5. Eliakim, R., Ovadia, A., and Sherer, D. M. (2000). Hyperemesis gravidarum: A current review. Am J Perinatol, 17(4), 207.

6. Christensen, B. L., Kockrow, E. O. (Eds.). 2003. Foundations of nursing (4th ed.). St. Louis: Mosby.

7. Goodwin, T. M. (2002). Nausea and vomiting of pregnancy: An obstetric syndrome. Am J Obstet Gynecol, 186(5, part 2), S184.

8. Koch, K. L. (2002). Gastrointestinal factors in nausea and vomiting of pregnancy. Am J Obstet Gynecol, 186(5, part 2), S198.

9. Hyperemesis Education & Research Foundation. "Laboratory findings." 2003. www.hyperemesis.org/hyperemesis-gravidarum/diagnosis/lab-findings.php (18 July 2003).

10. London, M. L. 2003. Maternal-newborn & child nursing. Upper Saddle River, NJ: Prentice Hall.

11. Hyperemesis Education & Research Foundation. "Suggested protocol." 2003. www.hyperemesis.org/health-professionals/suggested-protocol.php (18 July 2003).

12. Hyperemesis Education & Research Foundation. "Common medications." 2003. www.hyperemesis.org/hyperemesis-gravidarum/treatments/medications.php (3 July 2003).

13. Buttino, L., Coleman, S. K., et al. (2000). Home subcutaneous metoclopramide therapy for hyperemesis gravidarum. J of Perinatol, 20(6), 359.

14. Edelman, A., & Logan, J. R. "Pregnancy, hyperemesis gravidarum." 2001. www.emedicine.com/emerg/topic479.htm (3 July 2003).

 

Emil Vernarec, ed. Tristin Carpenter. Is it morning sickness—or something worse? RN Oct. 1, 2003;66:34.

Published in RN Magazine.