Efficacy of Macrolide Immunomodulation in Severe Sepsis.

In recent studies, the significant effects of macrolide antibiotics (azithromycin) on
immune response, unrelated to their anti-microbial properties, have been appreciated.
Clinical trials of macrolides added to - lactams in bacteremic Streptococcus pneumoniae
community-acquired pneumonia (CAP) have consistently demonstrated an absolute risk reduction
in mortality of 15% in most populations. Several cytokines including tumor necrosis factor
(TNF) interleukin (IL) -1 and IL-8 which are generally proinflammatory and IL-6 and IL-10,
which tend to be anti-inflammatory have been associated with sepsis. TNF is a cytokine that
for a number of reasons is thought to play a central role in the pathogenesis of sepsis and
septic shock. TNF concentrations are increased during clinical and experimental sepsis and
increasing concentrations and especially persistence of high concentrations of TNF during
sepsis are associated with decreased survival. Therefore, our primary aim is to determine
whether macrolide treatment of patients with severe sepsis has an advantageous
immunomodulatory and clinical effect compared to severe septic patients without macrolide
therapy. Our main hypothesis is macrolide use in addition to standard therapy in severe
septic patients has an advantageous immunomodulatory and clinical effect compared to
patients with severe sepsis not treated with a macrolide.

Inclusion Criteria:

1. Subject, or legal representative, has given written informed consent.

2. 18 years of age or older.

3. SIRS is defined as two or more of:

- Temperature > 38o C or < 36oC

- Heart rate > 90 beats/min

- Respiratory rate > 20 breaths/min or PaCO2< 32mmHg

- White blood cell count > 12.000/mm3; < 4000/mm3; or > 10% immature (band) forms.

4. Presence of a suspected or proven infection. Patients with suspected infection must
have evidence of an infection, such as white blood cells in a normally sterile body
fluid, perforated viscus, chest x-ray consistent with pneumonia and associated with
purulent sputum production, or a clinical syndrome associated with a high probability
of infection (for example, purpura fulminans or ascending cholangitis).

5. Presence of one or more sepsis-associated organ failure. The onset of the first
sepsis-associated organ failure must occur within the 48-hour period immediately
preceding initiation of study drug infusion. A patient must have an organ failure
attributable to the sepsis episode. The organ failure must be newly developed and not
explained by underlying disease processes or by effects of concomitant therapy.

- Cardiovascular: An arterial systolic blood pressure (SBP) of 90 mm Hg or a mean
arterial pressure (MAP) 70 mm Hg for at least 1 hour despite adequate fluid
resuscitation, adequate intravascular volume status, or the need for
vasopressors to maintain SBP 90 mm Hg or MAP 70 mm Hg.

- Renal: Average urine output <0.5 mL/kg/h for 1 hour despite adequate fluid
resuscitation

- Respiratory: Evidence of acute pulmonary dysfunction PaO2/FiO2 300 and,
clinical exam or pulmonary capillary wedge pressure not suggestive of volume
overload. If pneumonia is the suspected site of infection, the patient must have
a PaO2/FiO2 200.

- Hematology: Platelet count <80,000/mm3 or a 50% decrease in platelet count from
the highest value recorded over the last 3 days.

- Unexplained metabolic acidosis: Defined by (1) pH 7.30 or base deficit 5.0
mEq/L or (2) plasma lactate level >1.5 times the upper limit of normal.

Adequate fluid resuscitation or adequate intravascular volume is defined as either
pulmonary arterial wedge pressure 12 mm Hg or central venous pressure 8 mm Hg.
Vasopressors is defined as dopamine 5 g/kg/min or any dose of norepinephrine,
epinephrine, or phenylephrine. Dobutamine is not considered a vasopressor.

Exclusion Criteria:

1. Macrolide therapy indicated for clinical condition. If after randomization, the
treating physician determines that a macrolide is indicated and no other alternative
antibiotic is appropriate, the patient will be excluded from the trial. However, if
only one dose of azithromycin had been given and the treating physician decided to
stop it, azithromycin might be administered.

2. Known allergy to macrolides.

3. Prolonged QT syndrome or on medications with increased risk of QT prolongation.

4. Pregnant or lactating.

Immunosuppression as defined by:

1. Chemotherapy within the last 30 days,

2. Leukemia or lymphoma which is not in remission,

3. Solid organ or bone marrow/stem cell transplant,

4. Human Immunodeficiency Virus infection with CD4 count < 200 cells/mm3,

5. Chronic corticosteroid use equivalent to > 10 mg prednisone per day,

6. Patient or family decision to limit ICU care.