Volume 3 Supplement 1

19th International Symposium on Intensive Care and Emergency Medicine

Open Access

Urine output in the first twelve hours after cardiopulmonary bypass does not predict the development of renal impairment

  • SM Ali1 and
  • GR McAnulty1
Critical Care20003(Suppl 1):P208


Published: 16 March 2000

Full text

Hourly urine output is one of the foremost indices which are monitored in patients who have undergone cardiac surgery. Traditionally, a urine output of less than 0.5 ml/kg/h triggers intervention [1]. However, renal failure may supervene in patients who have seemingly adequate renal function according to conventional monitoring. In this pilot study we analysed urine output and alterations in serum creatinine in 31 consecutive patients in the first 12 h following coronary artery bypass and valvular surgery. We found that an `adequate' urine output alone is an unreliable predictor of subsequent renal impairment (indicated by a rise in 24 h post-operative serum creatinine by more than 50%). Six patients demonstrated such a rise in serum creatinine despite their producing urine outputs of greater than or equal to an average of 0.5 ml/kg/h. Of these, five subsequently required renal replacement therapy. This finding may have implications for the monitoring of cardiac patients who return to low-dependency patient care areas within 12 h of surgery.


Authors’ Affiliations

St George's Hospital Cardiothoracic Unit ITU/HDU


  1. Corso P, Eager MD: Postoperative care of the adult cardiac surgical patient. In: Shoemaker WC, et al. Eds. Textbook of Critical Care 3rd edn. Philadelphia: Saunders 1995, 604.Google Scholar


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