Distribution and time course of serum procalcitonin levels in burn patients.

Patients with burns exceeding 15% body surface area usually meet the criteria
of the Systemic Inflammatory Response Syndrome (SIRS). Sepsis is a clinical
entity which is defined by SIRS criteria plus the presence of an infection.
Clinically, SIRS is indistinguishable from sepsis. Therefore, other criteria
are needed to prove the presence of an infectious agent. Proof of infection is
attained when positive cultures of blood, sputum or other patient material are
found together with a high likelihood of pathogenicity of the agent i.e. the
laboratory results match the clinical picture. It is estimated that in only
20-30% of cases the diagnosis sepsis is supported by matching, postive
cultures. When antibiotic therapy is started before obtaining cultures this
number drops to approximately 1%.
Serum procalcitonine as a tool to detect infection has already been
investigated in several clinical settings with variable success. This is also
the case for burn patients. Up till now, however, prospective data for serum
procalcitonine values over a broad detection range in burn patients are
lacking. This study, together with the availability of a new, very sensitive
assay, aims to fill this gap. The data forthcoming from this study may help to
make the difficult, but important distinction between SIRS caused by burns on
one hand and SIRS complicated by a concomitant infection on the other hand.

This study aims to design a nomogram for the course of serum pro-calcitonin in
burn patients. For this purpose, a new, sensitive assay will be used. It is
expected that the nomogram will help to differentiate between patients with a
systemic inflammatory response syndrome (SIRS) that is the result of the burn
wound and patients with a SIRS and a concomitant bacterial infection.
Distinction between these 2 patient populations will provide a rationale for
the start of antibiotic therapy.

Open, prospective, observational study design.
Serum procalcitonin values will be measured from admittance until discharge of
the patient from the burn intensive care unit with a maximum of 14 days
(calculated from the day of the burn injury).
Serum PCT measurements will be performed together with routine laboratory
measurements.

For each included patient, data will be collected to describe the population
studied. In addition, data that are expected to correlate with the course and
height of serum PCT measurements are collected.

The following data will be collected:

- Type of burn injury (flame, scald, chemical).
- Alcohol intake.
- Substance abuse (yes/no).
- Age, height, weight.
- Medication on admittance.
- Smoking (yes/no, if yes approximate amount of cigarettes per day).
- Concomitant injury (yes/no).
- If yes: head injury, thoracic injury, abdominal injury, injury to
extremities, or otherwise.
- Calculated burned surface area.
- Co-morbidity, present before burn injury:
- Neurological.
- Cardiovascular (myocardial infarction, valve pathology, rhythm
disturbacies, cardiac failure, peripheral vascular insufficiency, thrombosis).
- Pulmonary: asthma, chronic obstructive pulmonary insufficiency.
- Renal failure: estimated glomerular filtration rate before admittance.
- Endocinological (diabetes, thyroid, otherwise).
- Other co-morbidity.
- Deficient immune system (yes/no, if yes cause).

Time schedule for PCT measurements.

- At admittance.
- Every 12 hours during first 3 days (calculated from time of burn injury).
- Daily from day 4 until discharge from burn intensive care unit or until day
14 after burn injury.

The following laboratory data will be collected on a daily basis:
- Leucocyte count.
- C-reactive protein.
- Serum sodium, potassium, creatinine.
- Clinical variabels:
- Temperature (highest/lowest) (°C).
- Systolic blood pressure (highest/lowest) (mmHg).
- Diastolic blood pressure (highest/lowest) (mmHg).
- Heart frequency (highest/lowest) (min-1).
- Fluids administered, diuresis, fluid balance).
- Dialysis (yes/no).
- Patient on ventilator (yes/no).
- Type of ventilation.
- Mean pressure (highest/lowest) (mmHg).
- Peak pressure (highest/lowest) (mmHg).
- PEEP (highest/lowest)(mmHg).
- FiO2 (highest/lowest).
- Oxygen delivered (calculated depending on mode of delivery e.g. face
mask, nasal cannula).
- Medication.
- Inotropic medication (yes/no).
- Dopamin (highest/lowest) (ml/h).
- Noradrenalin (highest/lowest) (ml/h).
- Enoximone (highest/lowest) (ml/h).
- SDD (yes/no).
- Glucocorticoids parenteral (yes/no).
- Antibiotics parenteral (yes/no).
- Antibiotics by nebulizer (yes/no).
- Antibiotics orally (yes/no).
- Type of wound covering.
- Events.
- Operation (yes/no).
- Insertion of intravenous catheter (yes/no, if yes: place of insertion).
- Positive culture (yes/no).
- Blood (date, type of infectious agent, contamination likely
(yes/no).
- Sputum (date, type of infectious agent, contamination likely
(yes/no).
- Wound (date, type of infectious agent, contamination likely
(yes/no).
- Other focus.

Blood will be drawn from the patients at times of routine blood laboratory
measurements. The burden for the patients will consist of the withdrawal of
approximately 4 ml extra blood per measurement.