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CASE

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MATERNAL HYPOTHERMIA AND FETAL BRADYCARDIA SECONDARY TO INFECTION:

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CASE REPORT AND

LITERATURE REVIEW Valerie 1. Morin, MD, FRCSC,l Nancy E. Kent, MD, FRCSC,2 Deborah M. Money, MD, FRCSC, 3 1Fellow,

2,3Clinical Instructors, Department of Obstetrics and Gynaecology, Division of Maternal Fetal Medicine, University of British Columbia ABSTRACT

A 31-year-old woman developed hypothermia secondary w a right pyelonephritis at 34 weeks of pregnancy. Her temperature dropped w 35.10 C. At the same time, there was a sustained fetal bradycardia of 90 w 95 beats per minute. The management of maternal sepsis complicated by hypothermia and fetal bradycardia is discussed. RESUME

Une patiente de 31 ans a developpe une hypothermie a34 semaines de grossesse a1a suite d' une pyelonephrite droite. Sa temperature s' est abaissee jusqu' a35,1 0C. Au meme moment, on notait une bradycardie foetale soutenue avec un rythme de base de 90 a95 battements par minute. La conduite face aune septicemie maternel1e compliquee par Ie developpement d' une hypothermie et d' une bradycardie foetale est discuree.

Jsoc OBSTET GYNAECOL CAN 1999;21(10}:969-73 KEY WORDS

Sepsis, hypothermia, fetal bradycardia. Received on January 5th, 1999. Revised and accepted on February 22nd, 1999. JOURNAL SOGe

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day history of chills and right flank pain prior to admission. Her temperature was 39.3°C, blood pressure was 98/50 mmHg and pulse 127 beats per minute. The only other abnormal finding was right flank tenderness. The fetal heart rate was reactive, with a baseline of 190 beats per minute. The white blood cell count was 30,400/ mm 3 and haemoglobin was 11.3g/dL. Urine dipstick showed pyuria. Both kidneys appeared normal when examined by ultrasound. An obstetrical ultrasound showed appropriate fetal size and normal amniotic fluid volume, urine and blood cultures were carried out and intravenous ampicillin two g every six hours was initiated. The patient remained toxic with her temperature reaching a maximum of 40,4°C eight hours after admission. Fetal heart rate monitoring revealed a tachycardia of 200 beats per minute. Due to her lack of response to therapy, the patienr was transferred to our tertiary care

The most common response to sepsis is hyperthermia but hypothermia may also occur. l Hypothermia is usually associated with a more severe infection. l Fetal bradycardia has rarely been described in association with maternal hypothermia secondary to sepsis. 2,3 We report a case of sustained fetal bradycardia associated with maternal urosepsis. The literature on this subject is reviewed. CASE REPORT

A 31-year-old, primigravid woman was admitted to a regional hospital at 34 weeks of gestation with evidence of right-sided pyelonephritis. Her past medical history was unremarkable and her pregnancy had been previously uncomplicated. She presented with a two-

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The temperature reached the lowest value of 35.1 0 Cat 0230h. At the same time, the fetal heart rate baseline was down to 90-95 beats per minute. JOURNAL SOGe

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,, , haemoglobin saturation of 99 percent in room air. The urine output was good (1 OOcc/hr). Fetal bradycardia was thought to be secondary to maternal hypothermia. The fetal heart rate was reactive with good short and long term variability and no other signs of fetal distress or hypoxia. Warm blankets and warm intravenous fluid were used to increase the patient's temperature. Over the next few hours her temperature slowly returned to normal. Glucose and thyroid function tests were normal. Blood and urine culture were subsequently positive for Escherichia Coli which was sensitive to ampicillin. Five days after initiating triple intravenous antibiotic therapy, the patient's regime was switched to oral amoxicillin. She was discharged home six days after admission and was to take amoxicillin 500 mg orally t.i.d. for seven days. The patient remained asymptomatic after discharge. Labour was induced at 38 weeks gestation for intrahepatic cholestasis of pregnancy. She had an uncomplicated vaginal delivery of a female baby weighing 3,385 g. Apgar scores were eight at one minute and nine at five minutes. The examination of the newborn was normal. The post-partum course was uneventful, and the patient was discharged home with her baby two days after delivery.

centre 24 hours after admission. She appeared pale, toxic and diaphoretic when she arrived; her temperature was 38.5 0 C, blood pressure was 120/70 mmHg and pulse 110 beats per minute. Physical examination was otherwise normal except for the persistent right flank tenderness. The fetal heart was reactive with a baseline of 150 beats per minute. Blood work showed a white blood cell count of 24,600jmm3, haemoglobin of 9.2g/dL and normal platelets. The creatinine level was 71umol/L. Triple intravenous antibiotic therapy was started: ampicillin two g every six hours, clindamycin 600 mg every six hours and gentamycin 120 mg for the first dose and 90 mg every eight hours thereafter. The first dose of clindamycin was given at 0040h and the first dose of gentamycin at OlOOh. The patient received 125 mg of meperidine at 0045h. She had also received a 650 mg acetominophen suppository before the transfer at 2045h. Over the next few hours the patient's temperature and fetal hearr rate baseline dropped slowly, as shown in Figure 1. At 0230h her temperature reached 35.10 C and the fetal heart rate was reactive with a low baseline of90 to 95 beats per minute (Figure 2). Maternal vital signs were otherwise stable, with a blood pressure of 110j80mmHg, pulse of 88 beats per minute and oxy-

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Fetal heart rate t racing showed a baseline of 90 to 95 beats per minute with good variability, reactivity and no deceleration.

JOURNAL SOGe

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,,, for Esherichia coli. She developed hypothermia with a lowest temperature of 35.10 C after her transfer to our centre. Her pulse and her blood pressure remained stable. The decrease in baseline fetal heart rate followed the decrease in maternal temperature (Figure 1), and the fetal bradycardia was thought to be secondary to maternal hypothermia. We found two case reports of maternal hypothermia and fetal bradycardia secondary to sepsis. 2,3 These two patients also had pyelonephritis secondary to Escherichia coli. 2,3 In our case, and in the cases reviewed, patients were managed with broad spectrum antibiotics and warming manoeuvres. 2,3 All fetuses showed reassuring fetal heart rate tracings despite the baseline bradycardia with reactivity and good short- and long-tenn variability and none of the patients was delivered immediately.2,3 Fetal bradycardia resolved gradually in all cases as maternal hypothermia was corrected with medical treatment. 2,3 All patients delivered at term, four to twelve weeks after the sepsis, and neonatal outcomes were good. 2,3 Tanaka et al. ll reported a case of fetal bradycardia with a sinusoid-like fetal heart rate pattern in association with maternal urosepsis and hypothermia. In the presence of maternal hypothermia and fetal bradycardia related to sepsis, aggressive treatment with broad spectrum antibiotics is advised after identification of the infective source. If the fetal heart rate is reassuring, the bradycardia management should be based primarily on the infection treatment and warming manoeuvres. In a study of experimental hypothennia in pregnant ewes, fetal oxygenation was normal despite the hypothermia when maternal pH and oxygenation were within normal limits. 12 Maternal sepsis is a serious condition which can usually be treated medically, and the stress of labour or Caesarean section should not be added if there are no signs of fetal compromise. An exception to this rule is if sepsis is secondary to chorioamionitis, in which case delivery is usually indicated. Newborns are also more at risk of neonatal complications if they are born hypothermic. 13 In summary, septic patients who develop hypothermia are usually suffering from a severe infection, and the first goal should be to identify and treat the infection aggressively. These patients should also be monitored closely because of the increased risk of septic shock in the presence of hypothermia. In our case and in the cases

DISCUSSION

Hypothermia is defined as an oral temperature of less then 36.5 0 C. Bradycardia is a common response to hypothermia in adults. Fetal and amniotic fluid temperature parallel maternal temperature. 4 Maternal hypothermia is a recognized cause of fetal bradycardia. Maternal hypothennia and fetal bradycardia have been described in association with the use of magnesium sulphate,5,6 cardiac surgery7 and sepsis. 2,3 Hyperthermia is the most common response to sepsis but normothermia and hypothermia may also occur.! Nine percent of septic patients will present with hypothermia, and this is usually associated with a more severe infection and bacteraemia.! Hypothermic patients have a worse prognosis than normothermic or hyperthermic patients, with an increased risk of septic shock and death. 1 The exact mechanism of hypothermia in septic patients is unknown. Bacteriallipopolysaccharides are responsible for many clinical manifestations associated with gram-negative pathogens. s Animals studies show that high doses of lipopolysaccharides induce the production of such mediators as interleukin,! TNF-alpha and nitric oxide which are possibly responsible for the development of hypothermia. S It is still unclear if these mediators act directly on the brain regulatory centres, or if the hypothennia is secondary to the hypotension, disruption of the circulation and heat exchange problems that they cause. s Hypothermia may be secondary to a decrease in systemic vascular resistance which can lead to an increase in heat 10st. 9 When heat loss exceeds heat production, even the increase in thermogenic activity may not be enough to maintain body temperature, and patients develop hypothermia. 9 Fetal bradycardia is defined by a baseline fetal heart rate below 120 beats per minute for 15 minutes or more. 10 Normal variability is one of the best indicators of an intact pathway between the central nervous system and the heart in the presence of bradycardia. 10 In the case presented, there was a sustained fetal bradycardia of 90 to 95 beats per minute, but the tracing showed good short- and long-term variability, reactivity and no deceleration (Figure 2). These findings were reassuring. Our patient was suffering from a right pyelonephritis and had secondary bacteraemia. The infection was confinned by urine and blood cultures which were positive

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reviewed, maternal hypothermia and fetal bradycardia were corrected with antibiotic treatment and warming manoeuvres. Neonatal outcomes were good in all cases.

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REFERENCES 1.

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Clemmer TP, Fisher CJ, Bone RC, Siotman GJ, Metz CA, Thomas FO. Hypothermia in the sepsis syndrome and clinical outcome. Crit Care Med 1992;20(10): 1395-1401 . Jadhon ME, Main EK. Fetal bradycardia associated with maternal hypothermia. Obstet GynecoI1988;72(3): 496-7. Hankins GD, Leicht T, Van Hook Jw. Prolonged fetal bradycardia secondary to maternal hypothermia in response to urosepsis. Am J PerinatoI1997;14(4):217-9. Assali NS, Westin B. Effects of hypothermia on uterine circulation and on the fetus. Proc Soc Exp Bioi Med 1962;109:485. Rodis JF, Vintzileos AM, Campbell WA, Deaton JL, Nochimson DJ. Maternal hypothermia: an unusual complication of magnesium sulfate therapy. Am J Obstet GynecoI1987;156(2):435-6. Cardosi RJ, Chez RA. Magnesium sulfate, maternal hypothermia, and fetal bradycardia with loss of heart rate variability. Obstet GynecoI1998;92(4):691-2.

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Lamb MP, Ross K, Johnston AM, Manners JM. Fetal monitoring during open heart surgery. Br J Obstet Gynaecol 1981 ;88(6):669-74. Blanque R, Meakin C, Millet S, Gardner CR. Hypothermia as an indicator of the acute effects of lipopolysaccharides: comparison with serum levels of IL 1B, IL6 and TNF. Gen PharmacoI1996;27(6):973-7 . Scarpace PJ, Bender BS, Borst SE. Escherichia coli peritonitis activates thermogenesis in brown adipose tissue: relationship to fever. Can J Physiol Pharmacol 1991 ;69 (6):761-7. Druzin ML, Gabbe SG . Antepartum fetal evaluation. In: Gabbe SG, Niebyl JR, Simpson JL (Eds). Obstetrics: Normal and Problem Pregnancies. 3rd ed. New York: Churchill Livingstone 1996:327-67. Tanaka M, Ikeda T. Suzuki T, Yakubo K, Fukuiya T. A case of fetal bradycardia and sinusoid-like fetal rate pattern associated with maternal hypothermia. Fetal Diagn Ther 1995;10(3):207-9. Vanderwater SL, Paul WM. Observation of the fetus during experimental hypothermia. Can Anaesth Soc J 1960;7:44. Reis MJ, White-Dodson H. Maternal hypothermia and persistent fetal bradycardia during the intrapartum process. J Obstet Gynecol Neonatal Nurs 1996;25(8): 674-80.

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JOURNAL SOGC

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