Article, Neurology

A rare cause of postpartum coma: isolated hyperammonemia due to urea cycle disorder

Unlabelled imagepostpartum coma: isolate”>Case Report

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American Journal of Emergency Medicine

journal homepage: www. elsevier. com/ locate/ajem

A rare cause of postpartum coma: isolated hyperammonemia due to Urea cycle disorder?

enzyme deficiencies in the urea cycle are rarely seen metabolic dis- eases in adulthood. Deficiencies of these enzymes or a lack of enzyme ac- tivity is asymptomatic in adults. Prolonged catabolic situations, surgery, and delivery may cause encephalopathy related to hyperammonemia in such patients. early diagnosis and treatment may be lifesaving for these patients. A case who was admitted with seizures initiated on the fifth postpartum day due to isolated hyperammonemia is presented here.

Eclampsia, embolism, hemorrhagia, septicemia, and psychosis are fre- quently seen causes of altered mental status in postpartum patients [1]. Another fatal and rare cause of coma is isolated hyperammonemia due to urea cycle disorder (UCD) in postpartum patients [1,2].

In emergency clinics, hyperammonemia is typically seen as a cause of metabolic comas in patients with acute or chronic hepatic insufficien- cy. Isolated hyperammonemia is seen in newborns with UCD. Most af- fected newborns are males; in adulthood, females mostly have UCD. Ornithine transcarbamylase deficiency (OTCD) is an X-linked inherited Metabolic disorder that is the most frequent cause of UCD in adults. Het- erozygote females may be totally asymptomatic until old age. However, during prolonged catabolic situations, such as delivery and postpartum periods, vomiting, disorientation, Seizure activity, and coma may occur due to hyperammonemia [1-3].

A case with seizures and coma on the fifth postpartum day due to hyperammonemia is presented here.

A 24-year-old primiparous woman was referred to our clinic due to in- tractable seizures on the fifth postpartum day. She was hospitalized on the second postpartum day because of nausea and vomiting after vaginal- ly giving birth to a healthy baby. Altered mental status, disorientation, and seizure activities were added to the clinical condition of the patient, and she was transferred to this clinic with the early diagnosis of eclampsia. Her initial Glasgow Coma Scale was 8 (E2, V2, M4). Her blood pressure was 100/60 mm Hg, her pulse rate was 120 per minute, her body temper- ature was 37.8?C, and her O2 saturation was 91%. She was known to be healthy and had no signs of preeclampsia. Laboratory tests and radiologic imaging were performed to exclude eclampsia and central nervous sys- tem abnormalities, such as infections and vascular diseases. Her lumbar puncture, cerebral computed tomography, and magnetic resonance imag- ing were all normal. An Abdominal ultrasonography revealed nothing pathologic, but her arterial ammonia level was 452 umol/L. There was no sign or finding of acute or chronic hepatic failure or cirrhosis. She was diagnosed as postpartum coma due to hyperammonemia related to OTCD, and she was hospitalized in the intensive care unit (ICU). During further diagnostic evaluations, her ammonia levels increased; she was started on sodium benzoate, and hemodialysis was performed. On the

? The authors declare that there was no support or funding for this study.

14th day of hospitalization, she died in the ICU despite all of the support- ive and specific treatment modalities. The Figure represents her plasma ammonia levels during hospitalization.

Hepatic coma related to hyperammonemia due to acute or chronic he- patic failure is frequently seen in emergency practice. However, isolated hyperammonemia without any signs of hepatic insufficiency is seen in metabolic diseases of newborns and in early childhood periods of life. A coma secondary to hyperammonemia due to UCD or insufficiency in en- zyme activity is rarely seen in adults. Urea cycle disorders are autosomal recessive and rare metabolic diseases that are seen in 1:300000 live births. However, OTCD is the most frequently seen type of UCD, which shows an X-linked inheritance pattern. Homozygous males are diagnosed in early newborn periods with severe clinical presentation, but heterozy- gous females are usually asymptomatic. These patients become symp- tomatic in catabolic periods, such as surgery, delivery, and trauma [1-3]. A coma in the postpartum period is usually related to eclampsia, hemo- lysis, elevated Liver enzymes, low platelet count syndrome; embolism; hemorrhagia; septicemia; and thrombosis. Clinicians usually plan diagnostic tests to exclude these diagnoses. In previously healthy coma patients with- out known hepatic diseases, plasma ammonia levels are not usually assayed. However, ammonia levels should be assayed in undiagnosed postpartum coma patients because early diagnosis and treatment of UCD are lifesaving for these patients. Undefined agitation and alterations in consciousness in

postpartum women may be diagnosed as postpartum psychosis [4].

Tihtonen et al [5] reported 2 cases, one of whom was previously di- agnosed as UCD; she had a healthy recovery period after a cesarean sec- tion with a convenient pretreatment. The second patient was diagnosed with a postpartum coma due to OTCD. She was investigated for UCD be- cause of having a sister who died 10 days ago, in her postpartum period. She was hospitalized in the ICU for 2 weeks, including 10 days intubated, and she was discharged with minimal neurologic sequela after 53 days of ward hospitalization [4]. This patient was referred to this clinic on the fifth day of initiation of the symptoms; she died on the 14th day of hospitalization.

Most cases in the literature are related to pregnancy and are present- ed in the postpartum period. Early diagnose of UCD is crucial. Patients should be started with 10% dextrose in the preoperative period before the beginning of the catabolic process. L-Arginine and sodium benzoate are treatment suggestions, with low-protein diets and oral sodium phenylbutyrate in early postpartum and postoperative periods. Frequent checks of plasma glucose and ammonia levels are also recommended [5]. In conclusion, UCD should be kept in mind as a possible diagnosis in patients presenting with postpartum coma. Plasma ammonia levels should be assayed, even if these patients do not have previously diag- nosed liver diseases. early initiation of treatment and family screening

are also suggested as lifesaving and preventative approaches.

0735-6757/(C) 2015

image of Figure

Figure. Plasma levels of ammonia during hospitalization.

Ayca Acikalin, MD* Nezihat Rana Disel, MD Ebru Cil Direk, MD

Department of Emergency Medicine, Faculty of Medicine

Cukurova University, Adana, Turkey

*Corresponding author at: Department of Emergency Medicine Faculty of Medicine, Cukurova University, 01260, Adana, Turkey Tel.: +90 5332566388 (Mobile); fax: +90 3223386153

E-mail address: [email protected]

Murat Turkeun Ilginel, MD Department of Anesthesiology, Faculty of Medicine Cukurova University, Adana, Turkey

Ahmet Sebe, MD

Department of Emergency Medicine, Faculty of Medicine

Cukurova University, Adana, Turkey

Sebnem Bicakci, MD Department of Neurology, Faculty of Medicine Cukurova University, Adana, Turkey


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