When a patient is really sick or you don’t know exactly what they have, it’s tempting to throw whatever you can at them. It’s terrifying to think that you might not be protecting a patient adequately when you have the chance.
Double coverage for Pseudomonas plays into this fear. It usually refers to the use of an anti-Pseudomonal, such as Zosyn (beta-lactam) PLUS a fluoroquinolone or aminoglycoside or even second beta-lactam, such as meropenem. Sometimes patients with severe sepsis or who are on ventilators are put on double coverage just to “cover all the bases.”
But research doesn’t support the empiric use of double-coverage. The only situations where “upfront” double coverage is justified is in neutropenic patients or patients on a ventilator at risk for ventilator-associated pneumonia where organism sensitivities are NOT known. If you do decide on double covering a patient, use a beta-lactam and aminoglycoside because that is the only combination there is good evidence for. Once sensitivities return, you should think more about how to practice good antibiotic stewardship and narrow the antibiotics!