title: [Identification of a period of renal ischemic vulnerability studying the changes in the indicators of acute renal insufficiency after heart surgery with extracorporeal circulation].
abstract: We studied the pre operative status and the 1st, 4th, 12th and 24th hours of the post operative period after open heart surgery with cardiopulmonary bypass with a crystalloid solution containing 10 gr of mannitol. We considered acute renal failure (ARF) as being any increase in plasma creatinine values of 0.25 mg/dl for the first 24 hours and 0.5 mg/dl for periods longer than 24 hours. Six patients had transitory ARF (28.5%). The maximum value of plasma creatinine was 2.3 mg/dl and no patients required renal function substitution. There were no deaths. We used as ischemia ARF indicators the urinary flow rate, urine/plasma creatinine ratio, urine/plasma osmolality ratio, sodium fractional excretion and free water reabsorption. We also measured the urinary N-A-Glucosaminidase (NAG). We found that creatinine clearance reached its lowest in the first and fourth hours. Beyond the fourth hour we observed, the urinary flow rate reduce significantly, the urine/plasma creatinine and osmolality ratios reach values traditionally associated prerenal ARF, an increase main free water reabsorption and a decrease in sodium fractional excretion with a close relationship between the less than 1 value and the increase in plasma creatinine. There was a significant NAG increase in the 24 th hour. The evidence of a vulnerability period for renal ischemic lesions between the 4 th and 12 th hour suggests a second mannitol administration during the first four hours of the post operative period.
authors.affiliation: Serviço de Nefrologia, Hospital de Santa Cruz, Carnaxide.
authors.forename: J D
authors.initials: JD
authors.lastname: Barata
authors.forename: M
authors.initials: M
authors.lastname: Bruges
authors.forename: C
authors.initials: C
authors.lastname: Oliveira
authors.forename: J
authors.initials: J
authors.lastname: Simões
authors.forename: L
authors.initials: L
authors.lastname: Bruges
authors.forename: J Q
authors.initials: JQ
authors.lastname: Melo
authors.forename: R
authors.initials: R
authors.lastname: Melo-Gomes
authors.forename: F
authors.initials: F
authors.lastname: Crespo
mesh_terms: D058186:Acute Kidney Injury / Q000175:diagnosis / Q000209:etiology*; D000368:Aged; D006348:Cardiac Surgical Procedures / Q000009:adverse effects*; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007511:Ischemia / Q000209:etiology*; D007668:Kidney / Q000098:blood supply*; D007677:Kidney Function Tests; D008297:Male; D008875:Middle Aged; D011184:Postoperative Period; D011446:Prospective Studies; D013997:Time Factors
vernacular_title: Identificação de um período de vulnerabilidade isquémica renal pelo estudo da evolução dos indicadores de insuficiência renal aguda após cirurgia cardíaca sob circulação extra corporal.