During the study period 1660 patients were admitted to the ICU. Sepsis /septic shock was diagnosed in 480 patients (28,9%). According to the study criteria 401 patients were excluded and further 79 were enrolled into the analysis. Sepsis was diagnosed in 32 (40,5%) and septic shock in 47 (59,5%) patients. Patients were severely ill with mean APACHE II score of 24. The DIC score according to the ISTH Criteria were calculated. None of the patients in the study group developed DIC at any time of observation.
Out of the 79 patients, 24 (30,4%) met the criteria of SALD. None of the patients developing SALD required extracorporeal liver support. Median bilirubin in the SALD group was 2,25(1,1 ÷ 4,16)mg/dl; 3,3(2,1 ÷ 5,67)mg/dl; 5,65(2,25 ÷ 6,95)mg/dl; 5,94(1,9 ÷ 7,6)mg/dl; 4,4(2,2 ÷ 5,6)mg/dl at days 1, 3, 5, 7 and 14 respectively. At the time of enrolment into the study, there was no difference in the severity of the disease between the groups. The characteristics of the patients is shown in table no.1.
Table 1
Patients characteristics at baseline (day1).
| All patients (n = 79) | Bilirubin < 2 mg/dl (no-SALD) (n = 55) | Bilirubin ≥ 2 mg/dl (SALD) (n = 24) | p-value |
Age (years) | 63,9 ± 16,1 | 67 (60 ÷ 74) | 61,0 (46,0 ÷ 78,0) | 0,63 |
Sex (female/male) | 31/48 | 22(40%)/33(60%) | 9(37,5%)/15(62,5%) | 0,83 |
SOFA (min-max) | 10 (7 ÷ 13) | 9(7 ÷ 13) | 12(9 ÷ 14) | 0,09 |
APACHE II | 24 (15 ÷ 30) | 24 (15 ÷ 30) | 24,5 (15,5 ÷ 28,5) | 0,98 |
Sepsis | 32 | 25 (78,1%) | 7 (21,9%) | 0,18 |
Septic shock | 47 | 30 (63,8%) | 17 (36,2%) |
Source of sepsis | |
Abdominal infection (ABD) | 32 (40,51%) | 23 (41,82%) | 9 (37,5%) | 0,91 |
Pulmonary infection (PNEU) | 27 (34,18%) | 17 (30,91%) | 10 (41,67%) | 0,5 |
Soft tissue infection (TISS) | 3 (3,8%) | 2 (3,64%) | 1 (4,17%) | 0,99 |
Neuroinfection (NEUR) | 4 (5,06%) | 3 (5,45%) | 1 (4,17%) | 0,99 |
Bloodstream infection (BSI) | 3 (3,8%) | 0 | 3 (12,5%) | 0,026 |
Urinary tract infection (UTI) | 6 (7,59%) | 6 (10,91%) | 0 | 0,17 |
UTI, PNEU | 1 (1,27%) | 1 (1,82%) | 0 | 0,99 |
NEUR, BSI | 1 (1,27%) | 1 (1,82%) | 0 | 0,99 |
PNEU, BSI | 2 (2,53%) | 2 (3,64%) | 0 | 0,99 |
Comorbidities | |
HTA | 37 (46,84%) | 26 (47,27%) | 11 (45,83%) | 0,89 |
DM | 23 (29,11%) | 19 (34,55%) | 4 (16,67%) | 0,18 |
CCD | 3 (3,8%) | 1 (1,82%) | 2 (8,33%) | 0,22 |
CA | 8 (10,13%) | 6 (10,91%) | 2 (8,33%) | 0,99 |
OBS | 8 (10,13%) | 5 (9,09%) | 3 (12,5%) | 0,69 |
CKD | 18 (23,68%) | 15 (27,27%) | 3 (12,5%) | 0,15 |
CPD | 10 (12,66%) | 8 (14,55%) | 2 (8,33%) | 0,72 |
ARY | 16 (20,25%) | 11 (22%) | 5 (20,83%) | 0,99 |
ALC | 10 (12,66%) | 7 (12,73%) | 3 (12,5%) | 0,99 |
NEUR | 4 (5,06%) | 4 (7,27%) | 0 | 0,31 |
OTH | 8 (10,13%) | 5 (9,09%) | 3 (12,5%) | 0,69 |
28-day survival | 49(62 ± 5,5%) | 37 (67,3 ± 6,3%) | 12 (50,0 ± 10,2%) | 0,12 |
Data are expressed as mean ± SD, median (interquartile range), or No. (%). p-value – comparison of groups with and without SALD. |
HTA – hypertension arterial, DM – diabetes mellitus, CCD – chronic cardiac disease, CA – cardiac arrest, OBS – obesity, CKD – chronic kidney disease, CPD – chronic pulmonary disease, ARY – arrhythmia, ALC – alcoholic disease, NEUR – chronic neurological disease, OTH – other |
There was no statistically significant difference in comorbidities between the groups. None of the patients in our study group had metabolic syndrome. Neither alcohol abuse nor obesity had statistically significant impact on the development of SALD. Apart from bloodstream infections (BSI), there was no difference in the source of sepsis between the groups. There was no case of BSI in bilirubin < 2 mg/dl group. We evaluated the association between plasma biomarkers measured within first 24 h after enrolment into the study. Analysed biomarkers were also investigated as predictors for 28-day survival. In Table 2. shown are the plasma biomarkers levels at the time of enrolment into the study (day 1). Only AST was significantly higher in SALD group, comparing to no-SALD group (p = 0,0234). Taking into consideration no difference in routinely measured biomarkers between the groups, we decided to analyse novel biomarkers at baseline.
Table 2
Plasma biomarkers at baseline (day 1).
| Normal plasma values | All patients (n = 79) | Bilirubin < 2 mg/dl (n = 55) | Bilirubin ≥2 mg/dl (SALD) (n = 24) | p-value |
Routinely measured biomarkers |
AST (U/l) | 5–34 | 590,6 ± 1970,8 | 51 (29 ÷ 155) | 124 (38 ÷ 325) | 0,02 |
ALT (U/l) | 0–55 | 310,9 ± 1109,7 | 46 (20 ÷ 81) | 61,5 (27 ÷ 102) | 0,16 |
Albumin (g/dl) | 3,2–4,6 | 2,34 ± 0,515 | 2,35 (2,0 ÷ 2,65) | 2,3 (1,8 ÷ 2,7) | 0,85 |
AT III (%) | 80–120 | 58,8 ± 20,2 | 58,5 (45 ÷ 81,1) | 53,3 (41,3 ÷ 61,3) | 0,08 |
INR | 0,9 − 1,3 | 1,45 ± 0,64 | 1,26 (1,12 ÷ 1,45) | 1,35 (1,16 ÷ 1,83) | 0,13 |
Prothrombin ratio (%) | 80–114 | 73,9 ± 19,8 | 79,7 (66,6 ÷ 87,8) | 73,7 (55,8 ÷ 86,3) | 0,27 |
APTT (s) | 21–30,1 | 42,7 ± 16,3 | 36,9 (30,9 ÷ 46,7) | 44,3 (33,9 ÷ 53,6) | 0,09 |
Novel biomarkers |
IP-10 (pg/ml) | 47–382 | 932,7 ± 1643,5 | 321,9 (198,7 ÷ 796,9) | 315,4 (140,7 ÷ 961,1) | 0,99 |
ET-1 (pg/ml) | 0,58 − 1,96 | 2,06 ± 1,60 | 1,72 (1,19 ÷ 2,45) | 1,54 (1,06 ÷ 2,39) | 0,79 |
PAI-1 (ng/ml) | 0,99 − 16,9 | 38,3 ± 53,3 | 13,1 (6,5 ÷ 29,9) | 51,6 (9,9 ÷ 74,9) | 0,02 |
TAT (ng/ml) | 0,5–10 | 21,3 ± 116,6 | 4,3 (2,6 ÷ 6,5) | 3,75 (2,83 ÷ 5,75) | 0,81 |
Hepcidin (ng/ml) | 82,4-56700 | 221,8 ± 167,1 | 195 (101,1 ÷ 321,9) | 158,2 (93,5 ÷ 217,9) | 0,35 |
Data are expressed as mean ± SD, median (interquartile range), or No. (%). p-value – comparison of groups with and without SALD |
Table 2
Plasma biomarkers at baseline.
| Normal plasma values | All patients (n = 79) | Bilirubin < 2 mg/dl (n = 55) | Bilirubin ≥2 mg/dl (SALD) (n = 24) | p-value |
Routinely measured biomarkers |
ASPAT (U/l) | 5–34 | 590,6 ± 1970,8 | 51 (29 ÷ 155) | 124 (38 ÷ 325) | 0,02 |
ALAT (U/l) | 0–55 | 310,9 ± 1109,7 | 46 (20 ÷ 81) | 61,5 (27 ÷ 102) | 0,16 |
Albumin (g/dl) | 3,2–4,6 | 2,34 ± 0,515 | 2,35 (2,0 ÷ 2,65) | 2,3 (1,8 ÷ 2,7) | 0,85 |
AT III (%) | 80–120 | 58,8 ± 20,2 | 58,5 (45 ÷ 81,1) | 53,3 (41,3 ÷ 61,3) | 0,08 |
INR | 0,9 − 1,3 | 1,45 ± 0,64 | 1,26 (1,12 ÷ 1,45) | 1,35 (1,16 ÷ 1,83) | 0,13 |
Prothrombin ratio (%) | 80–114 | 73,9 ± 19,8 | 79,7 (66,6 ÷ 87,8) | 73,7 (55,8 ÷ 86,3) | 0,27 |
APTT (s) | 21–30,1 | 42,7 ± 16,3 | 36,9 (30,9 ÷ 46,7) | 44,3 (33,9 ÷ 53,6) | 0,09 |
Novel biomarkers |
IP-10 (pg/ml) | 47–382 | 932,7 ± 1643,5 | 321,9 (198,7 ÷ 796,9) | 315,4 (140,7 ÷ 961,1) | 0,99* |
ET-1 (pg/ml) | 0,58 − 1,96 | 2,06 ± 1,60 | 1,72 (1,19 ÷ 2,45) | 1,54 (1,06 ÷ 2,39) | 0,79* |
PAI-1 (ng/ml) | 0,99 − 16,9 | 38,3 ± 53,3 | 13,1 (6,5 ÷ 29,9) | 51,6 (9,9 ÷ 74,9) | 0,02* |
TAT (ng/ml) | 0,5–10 | 21,3 ± 116,6 | 4,3 (2,6 ÷ 6,5) | 3,75 (2,83 ÷ 5,75) | 0,81* |
Hepcidin (ng/ml) | 82,4-56700 | 221,8 ± 167,1 | 195 (101,1 ÷ 321,9) | 158,2 (93,5 ÷ 217,9) | 0,35* |
*Mann-Whitney U test |
At baseline we observed statistically significant difference between the groups only for PAI-1. In the group with no SALD the levels of PAI-1 were significantly lower than in patients with SALD. Subsequently a ROC curve analysis for PAI-1 was conducted (Fig. 1).
PAI-1 values of > = 9 ng/ml can be good predictor of SALD, with sensitivity of 79,2% specificity of 41,8% and PPV − 37,3%, NPV − 82,1% (accuracy of 53,2%).
We postulated that at baseline bilirubin is not a good predictor of 28-day survival in patients with sepsis/ septic shock (log rank test, p = 0,117). On the contrary, what is shown on Fig. 2., PAI-1 seems to be a good predictor of 28-day survival in patients with sepsis/septic shock (log rank test, p = 0,00091). AST alone with cut-off value of 70U/l is not a good predictor of survival (log rank test, p = 0,0797; specificity 65,2%, sensitivity 68,6%, PPV 48,4%, NPV 81,4%, accuracy 67,6%), but in combination with PAI-1 it improves it's strength of 28-day ICU survival prediction (log-rank test, p = 0,00242; specificity 64,7%; sensitivity 73,9%, PPV 48,6%, NPV 84,6%, accuracy 67,6%).
As there was no statistically significant difference between the groups in severity of the disease (APACHE II score 24 vs. 24,5, p = 0,979), so we didn't analyze 28-day survival adjusting it to the APACHE II score at the time of enrolment.
The Spearman correlation was conducted between IP-10, ET-1, PAI-1, hepcidin, TAT on day 1, and bilirubin in consecutive days 3, 5, 7 and 14. Statistically significant positive correlation was observed between PAI-1 on day 1 and bilirubin in following days 3 ,5, 7 (respectively: day 3. R = 0,43, p = 0,00028; day 5. R = 0,46, p = 0,00052; day 7. R = 0,43, p = 0,00258). Statistically significant negative correlation was observed between hepcidin on day 1 and bilirubin in following days 5., 7., and 14. (respectively: day 5. R=-0,29, p = 0,0329; day 7. R=-0,32, p = 0,0244, day 14. R=-0,60, p = 0,0603).
The Spearman correlation was also conducted between IP-10, ET-1, PAI-1, hepcidin and TAT on day 1 and APACHE II and SOFA scores. There was statistically significant positive correlation between PAI-1 and SOFA (R = 0,26, p = 0,0198), but no correlation between hepcidin, IP-10, ET-1, TAT and SOFA or APACHE II scores, as well as no correlation between PAI-1 and APACHE II.
Figure 3 shows median novel biomarkers values on days 1, 3, 5, 7 and 14. On day 3. there is statistically significant difference between the groups in median values of endothelin-1 (p = 0,0279), PAI-1 (p = 0,0111) and hepcidin (p = 0,00194), but no difference in IP-10 (p = 0,523) and TAT (p = 0,522) values. On day 5. there is a statistically significant difference in PAI-1 (p = 0,00432) and TAT (p = 0,0420) values between the groups, but no difference in IP-10 (p = 0,0795), endothelin-1(p = 0,0761) and hepcidin (p = 0,0558). The statistically significant difference remains up to day 7. for PAI-1 and TAT with p = 0,00942 and p = 0,0414 respectively. There is no difference between the groups in median values of biomarkers on day 14.