[Characteristics of hemoglobin changes and its significance in critically ill patients]

To investigate characteristics of hemoglobin changes in surgical critically ill patients.

One hundred and ten consecutive critically ill patients admitted to the surgical ICU of Shanghai Ruijin Hospital were prospectively included in the clinical trial from January 2004 to December 2006. And changes of hemoglobin and prognosis were retrospectively analyzed. The inclusion criteria were surgical critical illness, APACHE II > or = 8 points, and admission to ICU within 48 hours after onset of critical illness, except for patients with bleeding. According to hemoglobin level before transfusion, 110 patients divide into the low level hemoglobin group (< or = 100 g/L) and the high level hemoglobin group (> 100 g/L). Time interval for valley value of hemoglobin within 28 days and incidence of hypo-hemoglobin (< or = 100 g/L) were investigated; the mean hemoglobin level, mean APACHE II scores, amount of concentrated red blood cells and rate of mechanical ventilation as well as duration of ventilation within 28 days were calculated. ICU survival rate was observed.

Level of hemoglobin in low level group was decreased significantly compared to high level group [(86.3 +/- 23.8) g/L vs. (112.9 +/- 20.4) g/L, P < 0.01]; and time of its valley values was shorter than that of high level group [(3 +/- 1) d vs. (5 +/- 2) d, P < 0.01]; the responding level of hemoglobin was (89.3 +/- 11.3) g/L and (110.0 +/- 12.5) g/L (P = 0.001), respectively. Incidence of hypo-hemoglobin was 92.9% in low level group and 0 in high level group within 28 days (P < 0.01). Hemoglobin level of high level group was significantly higher than that of low level group within 28 days [(120.2 +/- 12.5) g/L vs. (89.3 +/- 11.3) g/L, P < 0.05], and the total amount of blood transfusion in high level group was less significantly than that of low level group [(12.4 +/- 10.1) U vs. (24.0 +/- 15.6) U, P = 0.042]; mean APACHE II score in high level group was significantly lower than that of low level group [(8.7 +/- 2.4) vs. (13.2 +/- 4.3), P < 0.001]; rate of mechanical ventilation was no difference (56.4% vs. 52.7%, P = 0.765); but duration of mechanical ventilation was shorter than that of low level group [(12 +/- 5) d vs. (25 +/- 7) d, P < 0.001]. Survival rate in high level group in ICU was significantly higher than that of low level group (80.0% vs. 61.8%, P = 0.036).

Prolonged hypo-hemoglobin level (< or = 100 g/L) and valley value in advance suggest bad prognosis.