The golden hour and the silver day: Detection and correction of occult hypoperfusion within 24 hours improves outcome from major trauma

Background: The significance of occult hypoperfusion (OK) in the developmen t of respiratory complications IRC), multiple system organ failure (MSOF), and death, and the effect of rapid identification and correction of OH in t he severely injured trauma patient was investigated. Methods: A pilot retrospective study and the analysis of a prospective prot ocol to correct OH were performed. Pilot study: all trauma patients admitte d to our Level I trauma center between February and December of 1995, who s urvived greater than 48 hours, had an Injury Severity Score greater than or equal to 20, and intensive care unit stays greater than 48 hours were eval uated. Prospective study: patients admitted between January 1, 1996, and Ap ril 30, 1997, who survived greater than 24 hours, with Injury Severity Scor e greater than or equal to 20, and who were hemodynamically stable (systoli c blood pressure greater than 100, pulse rate less than 120, and urine outp ut greater than 1 mL/kg per hour) were included. Serum lactic acid (LA) lev els were measured at arrival and at proscribed intervals. In the pilot stud y, initial LA levels were examined in relation to outcome and complications . In the prospective study, patients with two consecutive LB levels greater than 2.5 mmoI/L underwent invasive monitoring and vigorous resuscitation t o correct their lactic acidosis. Results: Among the 31 patients studied in the pilot study, there were 4 dea ths, 6 cases of MSOF, and 13 patients with RC. Lactic acidosis and poor car diac performance, as evidenced by low cardiac index (CI) with normal fillin g pressures, were seen in all cases of MSOF and RC, as well as in ail death s. From these results, the prospective study was performed. Eighty-five int ensive care unit patients met criteria for inclusion in the study. Six addi tional patients were excluded because of severe, untreatable intracranial h ypertension at admission to the intensive care unit. Fifty-eight of these p atients had OH in the first 24 hours. Forty-four patients corrected their O H within 24 hours with vigorous resuscitation. There were no deaths, three cases of MSOF, and 10 cases of RC in those patients who corrected OB within 24 hours. Persistent OH (>24 hours) was seen in 14 patients, despite resus citative efforts, 43% of whom died. MSOF and RC were present in 36% and 50% of cases, respectively (p < 0.05). Conclusion: Initial lactic acidosis is associated with lower cardiac perfor mance and higher morbidity and mortality. Persistent OH is associated with higher rates of RC, MSOF, and death after severe trauma. Early identificati on and aggressive resuscitation aimed at correcting; continued elevation in serum lactate improves survival and reduces complications in severely inju red trauma patients.