 |
| Figure 1: Receiver operating characteristics (ROC) for positive microbiological blood cultures of PCT, CRP and ESR, individually and in combinations |
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| Figure 1: Receiver operating characteristics (ROC) for positive microbiological blood cultures of PCT, CRP and ESR, individually and in combinations |
| PCT | Interpretation | Risk of progression to severe systemic infection (severe sepsis) |
|---|---|---|
| <0.5 µg/L | Local bacterial infection is possible Systemic infection (sepsis) is not likely | Low |
| 0.5 - 2 µg/L | Systemic infection (sepsis) is possible, but various conditions are known to induce PCT as well | Moderate |
| 2 - 10 µg/L | Systemic infection (sepsis) is likely High risk for progression to severe systemic infection (severe sepsis) | High |
| >10 µg/L | Important systemic inflammatory response, almost exclusively due to severe bacterial sepsis or septic shock | High likelihood of severe sepsis or septic shock |
| Table 1: Interpretation of PCT-Q (BRAHMS) values and risk of progression to severe sepsis, adapted from Meisner et al. [7] | ||
| Bacteria | Number (%) |
|---|---|
| Gram-positive | 16 (59.3%) |
| Staphylococcus aureus (S. aureus) | 8 |
| Streptococcus pyogenes (S. pyogenes) | 2 |
| Streptococcus pneumoniae | 6 |
| Gram-negative | 11 (40.7%) |
| Klebsiella spp | 3 |
| Escherichia coli (E. coli) | 7 |
| Pseudomonas aeruginosa | 1 |
| Table 2: Gram-positive Vs. Gram-negative bacteria isolated from blood cultures | |
| Positive Blood Cultures | Negative Blood Cultures | Total | |
|---|---|---|---|
| PCT > 2 | 20 | 5 | 25 |
| PCT < 2 | 7 | 11 | 18 |
| Total | 27 | 16 | 43 |
| Positive Blood Cultures | Negative Blood Cultures | Total | |
| CRP > 0.01 g/L | 18 | 10 | 28 |
| CRP < 0.01 g/L | 9 | 6 | 15 |
| Total | 27 | 16 | 43 |
| Positive Blood Cultures | Negative Blood Cultures | Total | |
| ESR > 15 mm/hr | 19 | 10 | 29 |
| ESR < 15 mm/hr | 8 | 6 | 14 |
| Total | 27 | 16 | 43 |
| Table 3: Comparison between micriobiological blood cultures and procalcitonin, CRP and ESR in diagnosing bacterial sepsis | |||
| Patients′ characteristics | Frequency | Percent | |
|---|---|---|---|
| Age groups | < 60 years | 18 | 41.9 |
| 60 and above> | 25 | 58.1 | |
| Gender | Male | 24 | 55.8 |
| Female | 19 | 44.2 | |
| PCT | Positive | 25 | 58.1 |
| Negative | 18 | 41.9 | |
| ESR | Positive | 29 | 67.4 |
| Negative | 14 | 32.6 | |
| CRP | Positive | 28 | 65.1 |
| Negative | 15 | 34.9 | |
| Culture | Positive | 27 | 62.8 |
| Negative | 16 | 37.2 | |
| Table 4: Patients characteristics | |||
| Patients′ characteristics | Positive Culture (n = 27) | Negative Culture (n = 16) | Total | P value | |||
|---|---|---|---|---|---|---|---|
| Frequency | Percent | Frequency | Percent | ||||
| Age groups | < 60 years | 10 | 55.6% | 8 | 44.4% | 18 | 0.41 |
| 60 + | 17 | 68% | 8 | 32% | 25 | ||
| Gender | Male | 14 | 58.3% | 10 | 41.7% | 24 | 0.49 |
| Female | 13 | 68.4% | 6 | 31.6% | 19 | ||
| Table 5: Differences in characteristics between positive and negative microbiological blood cultures | |||||||
| Test(s) | Sensitivity (CI) | Specificity (CI) | PLR (CI) | NLR (CI) | OR (CI) | PPV (CI) | NPV (CI) | P value |
|---|---|---|---|---|---|---|---|---|
| PCT | 74.1% (0.55-0.87) | 68.8% (0.44-0.86) | 2.37 (1.11-5.07) | 0.377 (0.18-0.77) | 6.286 (1.61-24.57) | 80% (59.3-93.17) | 61.11% (35.75-82.7) | 0.006 |
| CRP | 66.7% (0.48-0.81) | 37.5% (0.18-0.61) | 1.067 (0.67-1.7) | 0.889 (0.39-2.03) | 1.2 (0.33-4.36) | 64.29% (44.07-81.36) | 40% (16.34-67.71) | 0.78 |
| ESR | 70.4% (0.52-0.84) | 37.5% (0.18-0.61) | 1.126 (0.72-1.77) | 0.790 (0.34-1.87) | 1.425 (0.39-5.26) | 65.52% (45.67-82.06) | 42.86% (17.66-71.14) | 0.59 |
| PCT & CRP | 51.9% (0.34-0.69) | 81.3% (0.57-0.93) | 2.765 (0.94-8.17) | 0.593 (0.37-0.94) | 4.667 (1.08-20.19) | 82.35% (56.57-96.2) | 50% (29.93-70.07) | 0.032 |
| PCT & ESR | 59.3% (0.41-0.75) | 81.3% (0.57-0.93) | 3.160 (1.09-9.18) | 0.501 (0.3-0.84) | 6.303 (1.45-27.45) | 82.35% (56.57-96.2) | 50% (29.93-70.07) | 0.01 |
| PCT, CRP & ESR | 37% (0.21-0.56) | 81.3% (0.57-0.93) | 1.98 (0.64-6.13) | 0.77 (0.53-1.12) | 2.55 (0.58-11.18) | 76.92% (46.19-94.96) | 43.33% 25.46-62.57) | 0.2 |
CRP: C-reactive protein, ESR: erythrocyte sedimentation rate, NLR: negative likelihood ratio, NPV: negative predictive value, OR: diagnostic odds ratio, PCT: procalcitonin, PLR: positive likelihood ratio, PPV: positive predictive value Table 6: Diagnostic value for positive microbiological blood cultures of PCT, CRP and ESR, individually and in combinations |
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| Test Result Variable(s) | Area | Standard Errora | Asymptotic Significanceb | Asymptotic 95% Confidence Interval | ||||
|---|---|---|---|---|---|---|---|---|
| Lower Bound | Upper Bound | |||||||
| PCT | 0.714 | 0.084 | 0.020 | 0.550 | 0.878 | |||
| ESR | 0.539 | 0.092 | 0.669 | 0.358 | 0.721 | |||
| CRP | 0.521 | 0.092 | 0.821 | 0.340 | 0.702 | |||
| PCT and CPR positive | 0.666 | 0.085 | 0.072 | 0.500 | 0.831 | |||
| PCT and ESR positive | 0.703 | 0.082 | 0.028 | 0.542 | 0.863 | |||
| PCT, CPR and ESR positive | 0.591 | 0.089 | 0.321 | 0.418 | 0.765 | |||
| a: under the nonparametric assumption. b: Null hypothesis: true area = 0.5 Table 7: Area under the curves (AUC) for positive microbiological blood cultures of PCT, CRP and ESR, individually and in combinations |
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