title: Pandemic 2009 influenza A in Argentina: a study of 337 patients on mechanical ventilation.
abstract: BACKGROUND
  The rapid spread of the 2009 Influenza A (H1N1) around the world underscores the need for a better knowledge of epidemiology, clinical features, outcomes, and mortality predictors, especially in the most severe presentations.
  
  
  OBJECTIVE
  To describe these characteristics in patients with confirmed, probable, and suspected viral pneumonia caused by 2009 influenza A (H1N1) admitted to 35 intensive care units with acute respiratory failure requiring mechanical ventilation in Argentina, between June 3 and September 7.
  
  
  METHODS
  Inception-cohort study including 337 consecutive adult patients. Data were collected in a form posted on the Argentinian Society of Intensive Care website.
  
  
  RESULTS
  Proportions of confirmed, probable, or suspected cases were 39%, 8%, and 53% and had similar outcomes. APACHE II was 18 +/- 7; age 47 +/- 17 years; 56% were male; and 64% had underlying conditions, with obesity (24%), chronic obstructive respiratory disease (18%), and immunosupression (15%) being the most common. Seven percent were pregnant. On admission, patients had severe hypoxemia (Pa(O(2))/Fi(O(2)) 140 [87-200]), extensive lung radiologic infiltrates (2.87 +/- 1.03 quadrants) and bacterial coinfection, (25%; mostly with Streptococcus pneumoniae). Use of adjuvants such as recruitment maneuvers (40%) and prone positioning (13%), and shock (72%) and acute kidney injury requiring hemodialysis (17%), were frequent. Mortality was 46%, and was similar across all ages. APACHE II, lowest Pa(O(2))/Fi(O(2)), shock, hemodialysis, prone positioning, and S. pneumoniae coinfection independently predicted death.
  
  
  CONCLUSIONS
  Patients with 2009 influenza A (H1N1) requiring mechanical ventilation were mostly middle-aged adults, often with comorbidities, and frequently developed severe acute respiratory distress syndrome and multiorgan failure requiring advanced organ support. Case fatality rate was accordingly high.
authors.affiliation: Servicio de Terapia Intensiva, Hospital Interzonal de Agudos San Martín de La Plata, La Plata, Buenos Aires, Argentina. elisaestenssoro@speedy.com
authors.forename: Elisa
authors.initials: E
authors.lastname: Estenssoro
authors.forename: Fernando G
authors.initials: FG
authors.lastname: Ríos
authors.forename: Carlos
authors.initials: C
authors.lastname: Apezteguía
authors.forename: Rosa
authors.initials: R
authors.lastname: Reina
authors.forename: Jorge
authors.initials: J
authors.lastname: Neira
authors.forename: Daniel H
authors.initials: DH
authors.lastname: Ceraso
authors.forename: Cristina
authors.initials: C
authors.lastname: Orlandi
authors.forename: Ricardo
authors.initials: R
authors.lastname: Valentini
authors.forename: Norberto
authors.initials: N
authors.lastname: Tiribelli
authors.forename: Matías
authors.initials: M
authors.lastname: Brizuela
authors.forename: Carina
authors.initials: C
authors.lastname: Balasini
authors.forename: Sebastián
authors.initials: S
authors.lastname: Mare
authors.forename: Gustavo
authors.initials: G
authors.lastname: Domeniconi
authors.forename: Santiago
authors.initials: S
authors.lastname: Ilutovich
authors.forename: Alejandro
authors.initials: A
authors.lastname: Gómez
authors.forename: Javiera
authors.initials: J
authors.lastname: Giuliani
authors.forename: Cecilia
authors.initials: C
authors.lastname: Barrios
authors.forename: Pascual
authors.initials: P
authors.lastname: Valdez
mesh_terms: D018806:APACHE; D000328:Adult; D001118:Argentina / Q000453:epidemiology; D015331:Cohort Studies; D004196:Disease Outbreaks; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000401:mortality; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000150:complications / Q000401:mortality* / Q000628:therapy; D008297:Male; D008875:Middle Aged; D011018:Pneumonia, Pneumococcal / Q000150:complications / Q000401:mortality; D011247:Pregnancy; D012121:Respiration, Artificial; D012128:Respiratory Distress Syndrome / Q000209:etiology / Q000401:mortality / Q000628:therapy*