Epidemiology of sepsis in Germany: results from a national prospective multicenter study

Abstract

Objective

To determine the prevalence and mortality of ICU patients with severe sepsis in Germany, with consideration of hospital size.

Design

Prospective, observational, cross-sectional 1-day point-prevalence study.

Setting

454 ICUs from a representative nationwide sample of 310 hospitals stratified by size. Data were collected via 1-day on-site audits by trained external study physicians. Visits were randomly distributed over 1 year (2003).

Patients

Inflammatory response of all ICU patients was assessed using the ACCP/SCCM consensus conference criteria. Patients with severe sepsis were followed up after 3 months for hospital mortality and length of ICU stay.

Measurements and results

Main outcome measures were prevalence and mortality. A total of 3,877 patients were screened. Prevalence was 12.4% (95% CI, 10.9–13.8%) for sepsis and 11.0% (95% CI, 9.7–12.2%) for severe sepsis including septic shock. The ICU and hospital mortality of patients with severe sepsis was 48.4 and 55.2%, respectively, without significant differences between hospital size. Prevalence and mean length of ICU stay of patients with severe sepsis were significantly higher in larger hospitals and universities (≤ 200 beds: 6% and 11.5 days, universities: 19% and 19.2 days, respectively).

Conclusions

The expected number of newly diagnosed cases with severe sepsis in Germany amounts to 76–110 per 100,000 adult inhabitants. To allow better comparison between countries, future epidemiological studies should use standardized study methodologies with respect to sepsis definitions, hospital size, and daily and monthly variability.

Appendix

Definitions of systemic inflammatory response syndrome (SIRS), sepsis, severe sepsis, and septic shock based on the ACCP/SCCM consensus conference definition [28]:

• 1. Systemic inflammatory response syndrome (SIRS). At least two of the following criteria need to be fulfilled: (a) temperature ≤ 36 or ≥ 38 °C; (b) tachycardia with heart rate ≥ 90 beats/min; (c) tachypnea with ≥ 20 breaths/min and/or paCO2 ≤ 32 mmHg or mechanical ventilation; (d) white blood cell count ≤ 4 or ≥ 12 g/l and/or left shift ≥ 10%

• 2. Sepsis: SIRS due to infection (clinically or microbiologically documented)

• 3. Severe sepsis: sepsis associated with at least one organ dysfunction

• 4. Septic shock: sepsis or severe sepsis with persistent hypotension despite adequate fluid resuscitation or the necessity of vasopressor administration to maintain a mean arterial blood pressure of 70 mmHg

If an infection and at least one organ dysfunction without SIRS was present within the 24-h period, the presence of SIRS within the preceding 48 h was assessed. If SIRS was present within this period, the patient was considered to have severe sepsis or septic shock.

 

Organ dysfunctions were defined as follows:

• 1. Acute encephalopathy: reduced vigilance; unrest; disorientation or delirium not influenced by psychotropic drugs

• 2. Hematological dysfunction: platelet count ≤ 100 g/l or decrease of > 30% over 24 h not caused by hemorrhage

• 3. Respiratory dysfunction: PaO₂/FiO₂ ≤ 250 mmHg if not caused by manifest pulmonary or cardiac disease or PaO₂/FiO₂ ≤ 200 mmHg in case of pneumonia as the only focus

• 4. Cardiovascular dysfunction: systolic blood pressure of ≤ 90 mmHg over 1 h in a patient being normotonous beforehand, or sustained decrease of ≥ 40 mmHg compared with the blood pressure at absence of other causes of shock

• 5. Renal dysfunction: urine output ≤ 0.5 ml/kg h⁻¹ for at least 1 h despite adequate fluid resuscitation and/or increase of serum creatinine to ≥ 2 times the upper limit of the normal reference range of the reporting laboratory (at presence of pre-existing impairment of renal function only one criterion need to be met)

• 6. Metabolic acidosis: pH ≤ 7.30 or base deficit ≥ 5.0 mmol/l or plasma lactate concentration ≥ 1.5 times the upper normal limit of the reporting laboratory