This isn't meant to be an official scientific document, so I apologize in advance for the sloppy work.
It's been widely known that increased fluid volume can lead to edema. My theory is based upon the intentional inducement of mild to moderate edema in order to increase capillary leakage from intravascular to extravascular spaces. Increased capillary leakage would allow increased antibiotics to diffuse from intravascular to extravascular space. The fluids I would think most appropriate would be normal saline and lactated ringers. Large macromolecules, such as hespan and blood, should not be used as their properties would prevent diffusion in the appropriate direction. Maintainance of CVP=12 would seem to induce adequate edema, although that may be somewhat excessive, especially in pts with aneurysms.
In some cases of pneumonia-induced ARDS(from whatever specific microbial agent, such as TB, streptococcus, etc), pulmonary edema may be extraordinarily beneficial. It's my theory that bacteria may reside in areas of the lungs that antibiotics may have difficulty penetrating to. Induction of pulmonary edema would allow for increased diffusion of the antibiotic and allow for deeper penetration to needed tissues where bacteria may reside.
While intentionally induced pulmonary edema may exacerbate the ARDS, several modes of ventilation exist to support the patient during these times, including bilevel. The clinician's own judgement, experience, and pt's lab values, should be used to determine the best mode of ventilation while also following conventional medication for adequate ventilation (ie, paralysis and sedation for pts on bilevel).
There are a variety of complications to be considered. The two most notable are hemorrhage from aneurysms, which may result from weakened blood vessels and increased intravascular pressures, and cerebral edema. To prevent hemorrhage, a decrease in CVP may be used, although it may also decrease the amount of extravascular leakage needed for proper antibiotic concentration. Personal judgement and experience will play a factor. To prevent cerebral edema, which will occur in a small minority of patients, I would suggest use of an intracranial pressure monitoring device.
In addition for aggressive fluid therapy, hypothermic therapy would also play an important factor in pt outcome. There are a number of trial studies using hypothermia, and you may look any number of them up (I recommend the Cool MI studies) and see for yourself the benefits of hypothermia. The cool MI studies suggest a temp between 33-34 degrees Celsius.
