Carolinas Research Day 2021

Respiratory Syncytial Virus ( RSV ) associated with Syndrome of Inappropriate Antidiuretic Hormone (SIADH) in Pediatric Patients: A Case Report Megan Donaldson, OMS-IV 1 ; Katelyn Hernandez, OMS-IV 1 ; Hanna S. Sahhar, MD, FAAP, FACOP 1,2 1 Edward Via College of Osteopathic Medicine-Carolinas Campus, Spartanburg, SC 2 Spartanburg Regional Healthcare System, Spartanburg, SC

CBR - 3

Abstract

Report of Cases

Conclusions

Case 1 A five-week-old male presented with one day of congestion, cough, and fever of 100.4 degrees F (Figure 1). Lab and bacterial cultures returned negative the infant was diagnosed with an unspecified upper respiratory infection and discharged home. Four days later the child returned with a worsening cough, decreased oral intake and lethargy. On presentation SpO2 was 93%. • Physical examination: twitching of the left face, upper and lower extremities, along with intercostal retractions, cyanosis and pallor. • Labs : significant for hyponatremia (corrected Na of 116 mmol/L ), hypercapnia (partial pressure of carbon dioxide of 62 mm/Hg), and FilmArray respiratory panel was positive for Human rhinovirus/enterovirus and Respiratory syncytial virus • CT head: negative of an acute intracranial abnormality • Chest x-ray : increased focal opacity evident at the left lung base compatible with pneumonia Patient was admitted to the PICU with the diagnosis of bronchiolitis and hyponatremia suspected as SIADH, for close monitoring and further testing. Respiratory status continued to decline, and the patient was intubated. • 3% NS 10ml/kg given to increase serum sodium, versed and fosphenytoin were started for seizure activity, and methylprednisolone (later switched to oral prednisone), albuterol and racemic epinephrine were given for nebulizer treatments. • Empiric cefotaxime, ampicillin, azithromycin and acyclovir were started until blood, urine, and CSF cultures returned. The infant’s symptoms gradually improved, he was extubated three days later and weaned to room air oxygenation. Follow-up serum sodium level was 135 mmol/L. Patient was discharged home after five days and scheduled for close follow-up with his primary care physician. Case 2 A four-month-old African American female presented to the emergency department with difficulty breathing for two days (Figure 2). On presentation the patient had a fever of 101.4 degrees F, pulse 186 beats per minute, and a SpO2 of 93% • Physical examination: s cattered rhonchi, rales and intercostal retractions • Labs: an unremarkable serum sodium of 137 mmol/L , and FilmArray respiratory panel was positive for Respiratory Syncytial Virus • Chest x-ray: mild left basilar density, likely atelectasis or consolidation • Ultrasound of the head : no evidence of acute germinal matrix hemorrhage The patient was admitted to the PICU with the diagnosis of bronchiolitis for close monitoring and further testing. Due to worsening shortness of breath two days later, the patient was placed on non- invasive ventilation. On repeat chest x-rays, the right upper lung lobe was repeatedly collapsing so flexible bronchoscopy was used and lavaged. On follow-up CXR, the narrowed bronchus showed improvement. Later this same day, the patient began showing generalized tonic clonic seizure activity and endotracheal intubation was performed. The patient was given versed, fosphenytoin, and phenobarbital. • BMP: Hyponatremia (corrected sodium of 111 mmol/L ) At this time 40 mL of 3% NS was given over 20 minutes. The patient received ceftriaxone and vancomycin along with methylprednisolone which was later switched to albuterol and a dose of dexamethasone. She remained on a ventilator for eight days and symptoms gradually improved, with a normal serum sodium of 137 mmol/L. The patient was discharged home two days following extubation.

Respiratory syncytial virus is a known cause of bronchiolitis or pneumonia in infants. Although rare, in documented cases of RSV , children can develop euvolemic hyponatremia, more commonly seen in those in the intensive care setting. These cases show similar symptomatology but vary in the timing of significant hyponatremic symptoms. Respiratory syncytial virus was confirmed in both individuals by the FilmArray respiratory panel. The children were then diagnosed with hyponatremia, however there is currently no evidence to link this hyponatremia to elevated levels of antidiuretic hormone. These cases emphasize the need to consider metabolic and endocrine derangements in the diagnosis of critical RSV related respiratory infections to ensure proper treatment and prevention of worse clinical outcomes. • Respiratory Syncytial Virus is a RNA virus that infects bronchiolar epithelial cells and modifies the inflammatory environment leading to symptomatology in a 2-8 day incubation period. 1 • It is the most common cause of a lower respiratory tract infection in children under the age of one year, with hospitalization highest when under 6 months old or premature infants under one year old. 2, 3 • One serious complication of RSV in children requiring intensive care is hyponatremia, due to excessive antidiuretic hormone (ADH) secretion. 4, 5 • The syndrome of inappropriate secretion of antidiuretic hormone, also known as SIADH, is a cause of euvolemic hyponatremia. Excess ADH secretion leads to increased water reabsorption and dilution of the serum, causing hyponatremia. • Hyponatremia is a life-threatening electrolyte abnormality with symptoms ranging from asymptomatic when mild; nausea, headache, vomiting when moderate; and coma, seizure, and death when severe. • Reported are two cases of confirmed RSV positive children with a complication of hyponatremia induced seizures. The cause of hyponatremia was attributed as SIADH. The 4-month- old female and the 5-week-old male were admitted to the pediatric intensive care unit (PICU) at Spartanburg Regional Hospital for treatment. Introduction

• Electrolytes and fluid intake must be monitored in infants positive RSV, as timely laboratory draws may prevent serious clinical outcomes. • Checking the volume status and serum sodium may be critical to saving a child’s life in the setting of RSV associated hyponatremia. It allows early detection and treatment of hyponatremia, preventing the severe negative effects of seizures, coma, and possible death. • By knowing this relationship between pulmonary processes and possible SIADH, clinicians can be guided to follow these patients closely for proper treatment.

Figure 2

Figure 1

References

1. American Academy of Pediatrics. Respiratory syncytial virus. In Red Book: 2018 Report of the Committee on Infectious Diseases, 31st ed, Kimberlin DW, Brady MT, Jackson MA, Long SS (Eds), American Academy of Pediatrics; 2018:682. 2. Hall CB, Weinberg GA, Iwane MK, et al. The burden of respiratory syncytial virus infection in young children. N Engl J Med. 2009; 360:588. 3. Pneumonia Etiology Research for Child Health (PERCH) Study Group. Causes of severe pneumonia requiring hospital admission in children without HIV infection from Africa and Asia: the PERCH multi-country case-control study. Lancet . 2019; 394:757. 4. Van Steensel-Moll HA, Hazelzet JA, Vander Voort E, Neijens HJ, Hackeng WHL. Excessive secretion of antidiuretic hormone in infections with respiratory syncytial virus. Arch Dis Child. 1990; 65:1237-1239. 5. Hanna S, Tibby SM, Durward A, Murdoch IA. Incidence of hyponatraemia and hyponatraemic seizures in severe respiratory syncytial virus bronchiolitis. Acta Paediatr. 2003; 92:430.

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