Saline Versus Lactated Ringer's Solution: The SOLAR Fluid Trial

Perioperative volumes of saline cause a mild acidosis compared with buffered fluids. On the
other hand, saline administration maintains plasma osmolality and better repletes vascular
volume which is an important goal of perioperative fluid administration. Currently, there is
no convincing evidence that either saline or buffered solutions are preferable. Consequently,
both types of fluid remain in common use at the Clinic and worldwide.

There has never been a large trial of perioperative saline and balanced salt solutions
comparing the incidence of major complications including acute kidney injury. The
investigators primary objective is thus to determine the relative safety of perioperative
saline and lactated Ringer's solution. Specifically, the investigators propose to test the:

1. Primary hypothesis that a composite of major in-hospital postoperative complications is
lower in patients given lactated Ringer's solution compared to normal saline.

2. Secondary hypothesis that acute kidney injury, measured by AKIN criteria, is lower in
patients given lactated Ringer's solution compared to normal saline.

The acquisition cost of saline and lactated Ringer's solutions is similar in the United
States. (Curiously, buffered solutions are far more expensive than saline in Great Britain.)
But to the extent that one fluid or the other provokes more complications, cost of care may
be increased with that fluid selection. Cost may also be increased by the need for additional
electrolyte monitoring and electrolyte replacement.

The investigators will therefore secondarily conduct an economic evaluation to determine the
relative incremental hospital cost of each fluid. To the extent that one fluid or the other
reduces cost (assuming similar complication rates), the Clinic will be able to reduce cost by
specifying the appropriate fluid without impairing quality.

Evidence that one fluid or the other causes few complications would be a strong quality
indicator that the Clinic should standardize perioperative fluid selection.