Introduction
Materials and methods
Patients
Patient characteristics | Postoperative patients mean and SD median (quartiles) | Survivors of sepsis mean and SD median (quartiles) | Non-survivors of sepsis mean and SD median (quartiles) | All patients with sepsis mean and SD median (quartiles) |
---|---|---|---|---|
Patient number (n =) | 50 | 60 | 20 | 80 |
Age | 57.1 ± 17.2
65.0 (47.0, 70.0)
| 58.8 ± 16.7
60.0 (46.0, 74.0)
| 53.4 ± 14.1
53.0 (47.5, 64.5)
| 57.5 ± 16.1
57.0 (47.3, 69.0)
|
Gender | 23/27 | 40/20 | 9/11 | 49/31 |
Primary diagnosis
| ||||
GI disease | 6 | 15 | 7 | 22 |
GI cancer | 14 | 7 | 4 | 11 |
Cancer other | 6 | 4 | 3 | 7 |
Urogenital disease | 3 | 2 | 1 | 3 |
Urogenital cancer | 7 | 1 | 1 | 2 |
Cardiovascular | 10 | 18 | 2 | 20 |
Lung disease | 0 | 9 | 1 | 10 |
Lung cancer | 0 | 1 | 0 | 1 |
Other diseases | 4 | 3 | 1 | 4 |
Infection type
| ||||
Gram-pos | 0 | 21 | 8 | 29 |
Gram-neg | 0 | 21 | 6 | 27 |
Fungal | 0 | 6 | 2 | 8 |
None | 0 | 12 | 4 | 16 |
Impedance aggregometry
Assays for procalcitonin, interleukin 6, and C-reactive protein concentrations
Statistical assessments
Results
Impedance aggregometry as a biomarker for the diagnosis of severe sepsis in critical illness
Testnormal range | Postop. patients mean and SEM median (quartiles) | Patients with sepsis mean and SEM median (quartiles) | Significance levelMann-Whitney-test |
---|---|---|---|
Aggregometry
| |||
ADP-test
53 - 122 AU
| 55.66 ± 3.80 52.85 (36.7, 76.00) | 31.87 ± 3.50 23.70 (8.30, 42.68) |
<0.001
|
AA-test
74 - 136 AU
| 78.08 ± 5.71 72.40 (41.78, 111.75) | 54.65 ± 4.81 41.10 (18.30, 87.72) |
0.001
|
Col-test
46 - 116 AU
| 68.13 ± 4.18 70.75 (44.38, 83.22) | 35.28 ± 3.52 26.75 (12.73, 45.75) |
<0.001
|
TRAP-test
94 - 156 AU
| 83.52 ± 4.38 77.30 (60.10, 108.65) | 58.20 ± 4.38 47.55 (25.08, 89.45) |
<0.001
|
Sepsis marker
| |||
Procalcitonin
0 - 0.5 ng/ml
| 2.09 ± 0.41 1.2 (0.44, 2.60) | 18.87 ± 5.13 4.55 (1.45, 17.60) |
<0.001
|
IL 6
0 - 3.4 pg/ml
| 297.11 ± 40.95 181.50 (83.50, 439.50) | 788.97 ± 310.20 95.85 (40.75, 401.50) |
0.045
|
CRP
0 - 0.5 mg/dl
| 12.18 ± 0.81 13.20 (8.55, 16.05) | 13.79 ± 1.02 13.10 (6.13, 18.58) |
0.813
|
ICU-Scores | |||
SAPSII | 21.4 ± 9.4 22.0 (15.5, 29.0) | 48.9 ± 17.1 51.0 (36.0, 65.0) |
<0.001
|
SOFA | 3.4 ± 2.5 4.0 (1.0, 6.0) | 11.6 ± 4.6 12.0 (8.0, 15.0) |
<0.001
|
Coagulation variables
| |||
INR
0.89 - 1.11
| 1.19 ± 0.02 1.17 (1.08, 1.29) | 1.38 ± 0.06 1.27 (1.11, 1.48) |
0.029
|
Thrombin time
14 - 21 s
| 18.1 ± 0.7 17.0 (15.8, 19.1) | 23.9 ± 1.7 18.6 (15.3, 24.8) | 0.105 |
Fibrinogen
210 - 400 mg/dl
| 406 ± 27 364 (312, 495) | 479 ±30 471 (240, 662) |
0.285
|
Platelets
160 - 350/nl
| 207 ± 14 196 (154, 245) | 137 ± 12 107 (57, 187) |
<0.001
|
Diagnosis of sepsis Test | AUC | Confidence interval | Significance level |
---|---|---|---|
Aggregometry
| |||
ADP | 0.759 | 0.677 - 0.842 | <0.001 |
AA | 0.669 | 0.577 - 0.761 | 0.001 |
Col | 0.808 | 0.731 - 0.884 | <0.001 |
TRAP | 0.700 | 0.661 - 0.778 | <0.001 |
Sepsis marker
| |||
PCT | 0.754 | 0.674 - 0.840 | <0.001 |
IL6 | 0.604 | 0.296 - 0.497 | 0.055 |
CRP | 0.513 | 0.412 - 0.614 | 0.813 |
ICU-scores
| |||
SAPS | 0.915 | 0.866 - 0.963 | <0.001 |
SOFA | 0.926 | 0.880 to 0.971 | 0.001 |
Coagulation variables
| |||
INR | 0.617 | 0.518 - 0.715 | 0.029 |
Thrombin time | 0.593 | 0.456 - 0.669 | 0.285 |
Fibrinogen | 0.563 | 0.456 - 0.667 | 0.285 |
Platelets | 0.736 | 0.649 - 0.823 | <0.001 |
Impedance aggregometry as a biomarker for the prognosis of severe sepsis in critical illness
Testnormal range | Survivorsmean and SEM median (quartiles) | Non-survivorsmean and SEM median (quartiles) | Significance level Mann-Whitney test |
---|---|---|---|
Aggregometry
| |||
ADP-test
53 - 122 AU
| 37.35 ± 4.39 32.30 (9.33, 48.98) | 15.03 ± 3.03 9.65 (4.45, 22.43) |
0.004
|
AA-test
74 - 136 AU
| 59.82 ± 5.75 43.45 (22.35, 93.85) | 39.15 ± 7.71 25.50 (10.03, 60.75) | 0.059 |
Col-test
46 - 116 AU
| 40.89 ± 4.29 33.40 (10.90, 48.78) | 18.43 ± 3.79 12.40 (6.50, 24.95) |
0.001
|
TRAP-test
94 - 156 AU
| 66.76 ± 5.09 54.75 (33.20, 97.08) | 32.50 ± 5.59 24.45 (13.20, 56.33) |
<0.001
|
Sepsis marker
| |||
Procalcitonin
0 - 0.5 ng/ml
| 17.74 ± 6.22 3.39 (1.14, 17.35) | 22.28 ± 8.79 5.56, (3.16, 17.83) |
0.091
|
IL 6
0 - 3.4 pg/ml
| 172.53 ± 32.81 77.5 (32.20, 160.75) | 2638.10 ± 1162 533.0 (72.4, 2059) |
0.001
|
CRP
0 - 0.5 mg/dl
| 13.74 ± 1.21 12.85 (6.13, 18.68) | 13.94 ± 1.93 13.65 (6.20, 18.15) |
0.833
|
ICU scores | |||
SAPSII | 47.2 ± 10.6 49.0 (32.0, 65.0) | 54.2 ± 12.3 (n.s.) 55.0 (43.8, 64.7) |
0.167
|
SOFA | 10.6 ± 4.6 11.0 (7.0, 14.0) | 14.6 ± 3.6 14.5 (12.0, 16.8) |
0.001
|
Coagulation variables | |||
INR 0.89 - 1.11 | 1.31 ± 0.06 1.19 (1.11, 1.40) | 1.64 ± 0.14 1.49 (1.24, 1.94) |
0.006
|
Thrombin time | 24.0 ± 2.0 | 23.4 ± 3.2 | |
14 - 21 s
|
19.0 (15.0, 25.1)
|
17.4 (16.1, 27.5)
| 0.955 |
Fibrinogen | 498 ± 33 | 414 ± 63 | |
210 - 400 mg/dl
|
512 (251, 676)
|
323 (231, 662)
|
0.159
|
Platelets | 154 ± 14 | 72 ± 11 | |
160 - 350/nl
|
131 (72, 224)
|
65 (44, 95)
|
<0.001
|
Prognosis of sepsis Test | AUC | Confidence interval | Significance level |
---|---|---|---|
Aggregometry
| |||
ADP | 0.700 | 0.582 - 0.818 | 0.008 |
AA | 0.626 | 0.488 - 0.764 | 0.093 |
Col | 0.734 | 0.607 - 0.862 | 0.002 |
TRAP | 0.756 | 0.641 - 0.871 | 0.001 |
Sepsis Marker
| |||
PCT | 0.617 | 0.254 - 0.511 | 0.117 |
IL6 | 0.731 | 0.126 - 0.413 | 0.002 |
CRP | 0.504 | 0.353 - 0.639 | 0.956 |
ICU scores
| |||
SAPSII | 0.605 | 0.267 - 0.522 | 0.160 |
SOFA | 0.732 | 0.154 - 0.382 | 0.002 |
Coagulation variables
| |||
INR | 0.719 | 0.569 - 0.868 | 0.006 |
Thrombin time | 0.505 | 0.347 - 0.662 | 0.955 |
Fibrinogen | 0.613 | 0.224 to 0.549 | 0.159 |
platelets | 0.752 | 0.135 to 0.361 | 0.001 |
Comparison of impedance aggregometry findings with platelet count
Conventional coagulation variables and scores as biomarkers for the diagnosis and prognosis of severe sepsis
Discussion
Conclusions
Key messages
-
Platelet aggregation, as determined by impedance aggregometry at Day 1, is markedly lower in patients with severe sepsis than in postoperative patients.
-
Platelet aggregation in non-survivors of severe sepsis is lower than in survivors.
-
Impedance aggregometry is a better biomarker for the diagnosis and prognosis of severe sepsis than conventional biomarkers and platelet count.