PLASMA-LEVELS OF HIGH-ENERGY COMPOUNDS COMPARED WITH SEVERITY OF ILLNESS IN CRITICALLY ILL PATIENTS IN THE INTENSIVE-CARE UNIT

Background. Plasma metabolic changes have been shown to reflect deteri oration of the energy state of tissue in studies in animals. This stud y evaluates whether high-energy compounds and their metabolites in pla sma reflect the clinical condition and predict outcome in critically i ll patients. Methods. Thirteen critically ill patients with major trau ma, severe septic shock, or cardiogenic shock (initial Acute Physiolog y and Chronic Health Evaluation [APACHE] II score greater than or equa l to 16) were studied. The APACHE II score was recorded daily until di scharge from the intensive care unit or death. The plasma contents of adenosine triphosphate, adenosine diphosphate, adenosine, inosine, hyp oxanthine, creatine phosphate, creatine, uric acid, and lactic acid we re determined daily. Fifteen healthy volunteers were used as control s ubjects. Results. All patients with an APACHE II score of 12 or less a t some time during their stay in the intensive care unit survived (n = 4); all patients with a score of 26 or higher died (n = 5). The initi al APACHE II median score for survivors was 21 (range 16 to 25; n = 7) and for nonsurvivors 24 (range 17 to 28; n = 6) (difference not signi ficant). The final APACHE II score for the survivors was 11 (range 3 t o 16) and for nonsurvivors 29 (range 20 to 47) (p < 0.01). The plasma metabolites were grouped according to the patients' APACHE II score of the day. There was a positive correlation between the severity of met abolic derangement and the APACHE II score. The plasma contents of ade nosine triphosphate and creatine phosphate were depleted with higher A PACHE II scores (p < 0. 01), whereas creatine and uric acid levels inc reased progressively (p < 0.001). The levels of adenosine, inosine, hy poxanthine, and lactic acid were elevated significantly in critically ill patients. Conclusions. Grouping patients with successively higher APACHE II scores revealed specific patterns of altered plasma metaboli sm, possibly reflecting different levels of tissue adenylate energy ch arge. However, neither the initial individual APACHE IT score nor any initial plasma metabolic level had any prognostic value in this group of critically ill patients, although the deterioration of the physiolo gic parameters was coexistent with specific metabolic changes.