Intensive care adult patients with severe respiratory failure caused by Influenza A (H1N1)v in Spain.
BACKGROUND
Patients with influenza A (H1N1)v infection have developed rapidly progressive lower respiratory tract disease resulting in respiratory failure. We describe the clinical and epidemiologic characteristics of the first 32 persons reported to be admitted to the intensive care unit (ICU) due to influenza A (H1N1)v infection in Spain.


METHODS
We used medical chart reviews to collect data on ICU adult patients reported in a standardized form. Influenza A (H1N1)v infection was confirmed in specimens using real-time reverse transcriptase-polymerase-chain-reaction (RT PCR) assay.


RESULTS
Illness onset of the 32 patients occurred between 23 June and 31 July, 2009. The median age was 36 years (IQR = 31 - 52). Ten (31.2%) were obese, 2 (6.3%) pregnant and 16 (50%) had pre-existing medical complications. Twenty-nine (90.6%) had primary viral pneumonitis, 2 (6.3%) exacerbation of structural respiratory disease and 1 (3.1%) secondary bacterial pneumonia. Twenty-four patients (75.0%) developed multiorgan dysfunction, 7 (21.9%) received renal replacement techniques and 24 (75.0%) required mechanical ventilation. Six patients died within 28 days, with two additional late deaths. Oseltamivir administration delay ranged from 2 to 8 days after illness onset, 31.2% received high-dose (300 mg/day), and treatment duration ranged from 5 to 10 days (mean 8.0 +/- 3.3).


CONCLUSIONS
Over a 5-week period, influenza A (H1N1)v infection led to ICU admission in 32 adult patients, with frequently observed severe hypoxemia and a relatively high case-fatality rate. Clinicians should be aware of pulmonary complications of influenza A (H1N1)v infection, particularly in pregnant and young obese but previously healthy persons.
Rello
Jordi
J
Critical Care Department, Joan XXIII University Hospital, CIBERes Enfermedades Respiratorias, IISPV, Mallafre Guasch 4, 43007 Tarragona, Spain. jrello.hj23.ics@gencat.cat
Rodríguez
Alejandro
A
Ibañez
Pedro
P
Socias
Lorenzo
L
Cebrian
Javier
J
Marques
Asunción
A
Guerrero
José
J
Ruiz-Santana
Sergio
S
Marquez
Enrique
E
Del Nogal-Saez
Frutos
F
Alvarez-Lerma
Francisco
F
Martínez
Sergio
S
Ferrer
Miquel
M
Avellanas
Manuel
M
Granada
Rosa
R
Maraví-Poma
Enrique
E
Albert
Patricia
P
Sierra
Rafael
R
Vidaur
Loreto
L
Ortiz
Patricia
P
Prieto del Portillo
Isidro
I
Galván
Beatriz
B
León-Gil
Cristóbal
C
D000328:Adult; D000998:Antiviral Agents / Q000008:administration & dosage / Q000494:pharmacology; D003422:Critical Care; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000235:genetics*; D007251:Influenza, Human / Q000150:complications* / Q000821:virology; D008297:Male; D008485:Medical Audit; D008875:Middle Aged; D009154:Mutation; D053139:Oseltamivir / Q000008:administration & dosage / Q000494:pharmacology; D011247:Pregnancy; D012131:Respiratory Insufficiency / Q000188:drug therapy* / Q000209:etiology* / Q000401:mortality / Q000503:physiopathology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012720:Severity of Illness Index; D013030:Spain / Q000453:epidemiology
D000998:Antiviral Agents; D053139:Oseltamivir