Publications Management System

H1N1 WITH ACUTE RESPIRATORY DISTRESS SYNDROME AND ENCEPHALOPATHY: A CASE REPORT

Received on 23 September 2016

Abstract

This article describes a case of Influenza A H1N1 in a female patient, 52 years old, previously healthy, presenting atypical pneumonia with fast progression to acute respiratory failure and relatively late introduction of Oseltamivir. The patient has developed secondary staphylococcal pneumonia, Acute Respiratory Distress Syndrome and Posterior Reversible Encephalopathy Syndrome. This patient was not previously vaccinated for influenza as she was not included in the priority populations defined by the National Immunization Program. The present increase of severe cases and deaths from H1N1 in 2016 supports the Center for Disease Control’s (CDC) guidelines to expand flu vaccination in order to reduce this disease’s morbidity and mortality.

Introduction

Flu is a universally distributed acute infection caused by the Influenza virus, which has been causing epidemies in several populations for centuries. In 2009, a new variant of this virus, the Influenza A H1N1, has started a pandemy in the Mexican city of La Gloria, Veracruz, which spread worldwide. The pandemy was declared ended in 2010 after a great number of casualties.1

The infection caused by the Influenza virus has a spectrum that varies from an upper respiratory tract illness without fever to a fulminant viral pneumonia. Most of the patients presents fever and cough, symptoms which may be followed by sore throat and rhinorrhea.1, 2 The best method for initial diagnosis is still the viral RNA detection by PCR.

The main causes that lead to hospitalization and admission to an Intensive Care Unit (ICU) are diffuse pneumonia, Acute Respiratory Distress Syndrome (ARDS), sepsis and shock. There is also the possibility of affection of the Central Nervous System (CNS), less frequent.1

For this specific treatment, it is used Oseltamivir, an antiviral that is more effective when initiated in the first 24 hours. Due to the virus mutations, annual vaccination campaigns are recommended.1, 2

We report a case of a patient with influenza A (H1N1) that evolved to acute diffuse pneumonia, ARDS and Posterior Reversible Encephalopathy Syndrome (PRES).

Case report

Patient L.S.R., woman, caucasian, 52 years old, with Gastroesophageal Reflux Syndrome, in daily use of Pantoprazole, without history of smoking or alcoholism. She has complained of fever that evolved with myalgia, dry cough, earache, nausea, vomit, adynamia and hyporexia. She looked for medical care, being medicated with Azithromycin. Five days later, she was admitted to the hospital and, at the physical exam, presented a regular general health status, dehydrated, pale, anicteric, no fever (37.4oC). Oral examination was normal, no lymphadenomegalies were detected and there was normal lung auscultation. Chest radiography (See Figure 1) showed bilateral extensive pulmonary infiltrates that were mainly basal with atelectasis and associated pleural effusion. The antibiotic therapy was changed to Levofloxacin.

Figura 1 – Chest radiography in posteroanterior incidence

figura 1 art 9

Source: the author

The patient has evolved to severe dyspnea, was then transferred to the ICU and the antibiotic therapy was changed to Ceftriaxone, Clarithromycin and Sulfamethoxazole/Trimethoprim (SMX/TMP). She has developed septic shock and respiratory failure, so mechanical ventilation was needed and a tracheostomy was performed. Computed Tomography (CT) of the chest showed bilateral interstitial pneumonia in the right lung and left lung basis with patchy ground glass opacity, evidencing ARDS. Bacterioscopies and cultures, negative BAAR and ELISA for HIV led to the suspension of SMX/TMP and initiation of Oseltamivir.

On the eighth day of ICU, there was radiological worsening, blood cultures and cultures of trachea secretion revealed oxacillin-resistant Staphylococcus aureus. These findings have oriented the beginning of Vancomycin and Meropenem, with interruption of the other antibiotics. Oseltamivir was kept for only 5 days. On the tenth day, Influenza A H1N1 was confirmed by PCR done in a fluid sample collected through nasal swab at hospital admission. On the seventeenth day, she presented eye aperture and response to stimulus, without obeying to commands though. All antibiotics were stopped and the patient was put into macro ventilation.

On the twentieth day, she presented right paresis, left plegia and partial facial paralysis to the left as well. Brain CT and Magnetic Resonance Imaging – MRI (See Figure 2) showed images compatible with intraparenchymal hemorrhage in front parietal and right occipital lobes, measuring 2.2cm x 2.9cm and 1.7cm x 2.3cm respectively, with edema and blurring of adjacent sulcus.

Figure 2: MRI showing: a) Sequence in T1 with hemorrhagic lesions in the frontal and right parietal regions; B) and C) Flair sequences showing hypersignal of the white matter in the frontoparietal regions and hemorrhagic lesions to the right

figura 2 art 9
Source: the author

Acute hemorrhagic leukoencephalitis (Weston-Hurst Syndrome) was suspected and intravenous bolus (pulse) doses with methylprednisolone was begun and kept for five days. After corticotherapy, the patient recovered the movements of the left lower limb. Arterial and venous angiographies of the skull have evidenced arterial narrowing and NRM has showed reduction of edema and hemorrhagic areas. 34 days after ICU admittance, all the respiratory support was withdrawn, leaving only the tracheostomy, with the patient being relocated to a room. The hospital discharge occurred 42 days after the admittance. Quick neurological improvement and the imaging review of MRI and CT of the skull set the diagnosis of Posterior Reversible Encephalopathy Syndrome. The patient evolved with physical therapy at home, without any motor and respiratory sequel.

Discussion

Caused by the Influenza virus, the flu is capable to cause annual recurrent epidemies and, less often, pandemies. In June 2009, four months after its outbreak in Mexico, the first Influenza pandemy of the 21st century was declared by the World Health Organization, as a “pandemy of a new virus”, the Influenza A H1N1. Since August of that very year, 177 countries have reported 182,166 cases and 1,799 deaths. The end of the pandemy was declared in August 2010, but it was not before 200 million people were infected and nearly 18,500 casualties were confirmed.1,2 From 2013 to 2014, and again in 2016, the subtype H1N1 returned, resulting in significant morbidity and mortality.

The H1N1 flu is highly contagious, being typically a mild upper respiratory tract infection associated to fever, cough, myalgia, rhinorrhea, conjunctivitis and dispnea.1,2 Although generally self-limiting, it includes a subset of patients with unfavorable clinical course, being the severe Influenza infection normally associated to pulmonary complications.1 Besides commonly seen in elderly adults or in the ones with high risk conditions, it is possible to state that, taking the case report as an example, the age group under 60 years old and the absence of comorbidities are not indicators of risk absence for the unfavorable evolution.1, 2

It is known that the evolution of the H1N1 infection depends on the form each individual pro and anti-inflammatory inner mechanisms interact. Initially, a major cytotoxic T lymphocytes stimulation occurs and is crucial for viral elimination. At the same time, a progressive increase in the production of Interleukin 10 (IL-10), a T cell inhibitor, avoids hyper stimulation of T cells. Severe and fatal cases have been linked to low and high IL-10 levels. In the first condition, cytotoxic T lymphocytes hyper stimulation, causes autoimmunity lesions; on the other hand, high inhibitory action of IL-10 on T lymphocytes compromises the protection against secondary infection.3

The main causes which lead to hospitalization and ICU need are pneumonia, ARDS, and, sometimes, sepsis and shock.1 A 2009 study involving 189 ICUs conducted in Australia and New Zealand evidenced that almost half of the patients with confirmed H1N1 infection (48.8%) presented ARDS or viral pneumonitis and 20.3% were clinically diagnosed with secondary bacterial pneumonia, normally caused by Staphylococcus aureus (often methicillin resistant), Streptococcus pneumoniae and Streptococcus Pyogenes.1,4

Extra pulmonary manifestations, such as of the CNS, were also observed in the H1N1 infection. Occasional cases of neurological manifestation were reported, including some fulminant cases.1,2 As it was showed, the patient presented with tetraparesis, which led to the hypothesis of Weston-Hurst Syndrome. However, a very favorable evolution, opposed to what is normally observed in that syndrome, allied with the revision of brain MRI and CT performed strongly defined the hypothesis of PRES.5

Clinical suspicions and diagnosis accuracy of Influenza A H1N1 depend on whether the case is a sporadic one or occurs during a known outbreak. As described, the patient was admitted with all the Gram staining and cultures negative. However, it was posteriorly detected positive PCR to H1N1 through nasal swab, being the viral RNA identification, with this technique, the best method for the initial diagnosis.

Thus, although very important for the diagnosis, the introduction of the antiviral treatment must not wait for laboratorial confirmation. Patients with suspect clinical presentation should be treated empirically treated as soon as possible. The current AH1N1 subtype virus that circulates is still susceptible to neuraminidases inhibitors, Oseltamivir and Zanamivir, but it is very resistant to Amantadine and Rimantadine. Oseltamivir is the most used drug and it reduces hospitalization time and risk of progression to severe illness, especially when started early.1

As the available options for flu control are limited, it is recommended yearly prevention through vaccination. Children, pregnant women, immunosuppressed individuals, people with chronic diseases, elderly people and healthcare professionals are the priority groups. An unfavorable ending is not necessarily associated to previous debilitating conditions, but also to the individual immune response pattern during the inflammatory process, beyond the virulence of the infecting strains. The unpredictability of each particular kind of response weakens the current definition of priority groups for vaccine protection. In the present case, the patient did not fit into any criteria for vaccination coverage of the National Immunization Program of the Health Ministry. The Center for Disease Control/ USA (CDC) and some experts of World Health Organization (WHO) have recommended universal vaccination for the flu.3,6

References

  1. Writing Committee of the WHO Consultation on Clinical Aspects of Pandemic (H1N1) 2009 Influenza. Clinical Aspects of Pandemic 2009 Influenza A (H1N1) Virus Infection. N Engl J Med [Internet]. 2010 [citado 2016 fev.28];362(18):1708-19. Disponível em: http://www.nejm.org/doi/full/10.1056/NEJMra1000449.
  2. Fischer II WA, Gong M, Bhagwanjee S, Sevransky J. Global burden of Influenza: Contributions from Resource Limited and Low-Income Settings. Glob Heart [Internet]. 2014 [citado 2016 fev.28];9(3):325-36. Disponível em: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4327778/.
  3. Lee N, Wong CK, Chan PKS, Chan MCW, Wong RYK, Lun SWM, et al. Cytokine Response Patterns in Severe Pandemic 2009 H1N1 and Seasonal Influenza among Hospitalized Adults. PLoS One [Internet]. 2011 [citado 2016 fev.28];6(10): e26050. Disponível em: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3192778/.
  4. The ANZIC Influenza Investigators. Critical Care Services and 2009 H1N1 Influenza in Australia and New Zealand. N Engl J Med [Internet]. 2009 [citado 2016 fev.28];361(20):1925-34. Disponível em: http://www.nejm.org/doi/full/10.1056/NEJMoa0908481.
  5. Bartynskia WS. Posterior Reversible Encephalopathy Syndrome, Part 1: Fundamental Imaging and Clinical Features. AJNR [Internet]. 2008 [citado 2016 fev.28];29: 1036-1042. Disponível em: http://www.ajnr.org/content/29/6/1036.long.
  6. Andrew TK, Ciro VS, Larry KP, William LA. General Recommendations on Immunization: Recommendations of the Advisory Committee on Immunization Practices (ACIP). Centers for Disease Control and Prevention [Internet]. Atlanta, USA; s.d. [citado 2016 fev.28].  Disponível em:http://www.cdc.gov/mmwr/preview/mmwrhtml/rr6002a1.htm

Authors

Lauro Ferreira da Silva Pinto Neto1; Amanda Araújo2; Daniela Lerback Jacobsen3; Renata Sartório da Silva Rangel4

1 PhD from the Federal University of Espírito Santo – UFES, Medical Doctor, Associate Professor of the Escola Superior de Ciências da Santa Casa de Misericórdia de Vitória – EMESCAM.

2,3,4 Undergraduate students of the Medical School of the Escola Superior de Ciências da Santa Casa de Misericórdia de Vitória – EMESCAM.

2024 - SALUS JOURNAL - All rights reserved