title: H1N1 infection and the kidney in critically ill patients.
abstract: BACKGROUND
  Acute renal failure due to viral infections is rare. We assessed the development of acute kidney injury (AKI) in critically compromised patients due to the H1N1 influenza virus.
  
  
  METHODS
  All patients with a PCR -confirmed diagnosis of H1N1 influenza infection admitted to the intensive care unit between May and July 2009 were retrospectively studied. Thereafter, the risk factors associated with the development of acute renal injury, the requirements of acute hemodialysis (HD) and death were analyzed.
  
  
  RESULTS
  Twenty-two patients with H1N1 pneumonia were included: age: 52.91 ± 18.89 years; gender: males 11 (50%); chronic airway disease: 9 (41%); oncohematological disease: 8 (36.7%); cardiovascular disease 5 (22.7%); chronic renal insufficiency: 4 (18.2%); obesity 3 (13.6%); concomitant pregnancy: 2 (9.1%); diabetes mellitus: 2 (9.1%); previous influenza A vaccination: 9 (41%). All patients received oseltamivir within 48 hours of presumed diagnosis. Seventeen patients (77.3%) developed fever initially. Six patients (27.3%) required noninvasive ventilation assistance and 15 patients (68.2%) received invasive ventilatory support. Mean days on mechanical respiratory assistance: 11 ± 10.35. Arterial partial pressure of oxygen/fraction of inspired oxygen ratio: 140.11 ± 83.03 mmHg. Inotropic drugs were administered to 15 patients (68.2%). Fourteen patients (63.6%) developed AKI. Mean highest creatinine levels: 2.74 ± 2.83 mg/dl. Four patients (18.2%) needed renal replacement therapy with a mean duration of 15 ± 12 days. Six patients (42.9%) recovered renal function. AKI was associated with pregnancy, immunosuppression, high APAC HE, SOFA and MURRA Y scores, and less time on mechanical ventilation assistance, hemodynamical instability and thrombocytopenia. HD requirements were associated with elevated SOFA scores (12.25 ± 1.75 vs. 6.22 ± 0.8, p<0.05), elevated creatine phosphokinase (933 ± 436.6 vs. 189.9 ± 79.3 U/L, p<0.05) and alanine transferase levels (843.3 ± 778.8 vs. 85.33 ± 17.4 U/L, p<0.05). Twelve patients died (54.6%), 10 of whom had acute renal failure (83.3%) and 3 had been on acute HD (25%). Mortality was associated with higher APACHE, SOFA and Murray scores, a higher oseltamivir dose (253.1 ± 25.8 vs. 183.8 ± 27.6 mg, p<0.05), lower oxygen inspired fraction/alveolar pressure ratio (99.3 ± 12.2 vs. 196.3 ± 33.9 mmHg, p<0.01), thrombocytopenia (88966 ± 22977 vs. 141200 ± 17282 mm3, p<0.05), hypoalbuminemia (1.82 ± 0.1 vs. 2.61 ± 0.2 g/dl, p<0.01), acute renal failure (10 vs. 4, p<0.05), oligoanuria (5 vs. 0, p<0.05) and lack of recovery of renal function (2 vs. 4, p<0.01). Three out of 4 (75%) of the hemodialyzed patients died.
  
  
  CONCLUSIONS
  In the critically ill due to H1N1 pneumonia, renal insufficiency was a frequent complication, demanding renal replacement therapy in 18% of cases. The need for HD was associated with an elevated risk of death. Mortality was mainly associated with multiple organ failure, oligoanuria, acute renal injury and a lack of recovery of renal function.
authors.affiliation: Nephrology Service, Hospital Británico de Buenos Aires, Perdriel 74, Buenos Aires, Argentina. htrimarchi@hotmail.com
authors.forename: Hernán
authors.initials: H
authors.lastname: Trimarchi
authors.forename: Gustavo
authors.initials: G
authors.lastname: Greloni
authors.forename: Vicente
authors.initials: V
authors.lastname: Campolo-Girard
authors.forename: Sergio
authors.initials: S
authors.lastname: Giannasi
authors.forename: Vanesa
authors.initials: V
authors.lastname: Pomeranz
authors.forename: Esteban
authors.initials: E
authors.lastname: San-Roman
authors.forename: Fernando
authors.initials: F
authors.lastname: Lombi
authors.forename: Laura
authors.initials: L
authors.lastname: Barcan
authors.forename: Mariano
authors.initials: M
authors.lastname: Forrester
authors.forename: Salomón
authors.initials: S
authors.lastname: Algranati
authors.forename: Romina
authors.initials: R
authors.lastname: Iriarte
authors.forename: Guillermo
authors.initials: G
authors.lastname: Rosa-Diez
mesh_terms: D058186:Acute Kidney Injury / Q000209:etiology*; D000328:Adult; D000368:Aged; D003402:Creatine Kinase / Q000097:blood; D016638:Critical Illness; D005260:Female; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype; D007251:Influenza, Human / Q000150:complications*; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies
chemical_list: D003402:Creatine Kinase