Cardiopulmonary bypass prime composition: beyond crystalloids versus colloids.

INTRODUCTION: In the literature addressing cardiopulmonary bypass (CPB) prime composition, there is a considerable lack of discussion concerning plasma osmolality changes induced by using a hyperosmolar prime. With this study, we try to determine the magnitude and temporal relationship of plasma osmolality changes related to the use of a hyperosmolar CPB prime.

METHOD: In this prospective observational study performed in a university hospital setting, we enrolled thirty patients scheduled for elective coronary bypass surgery. Plasma osmolality was analysed on eight occasions. A hyperosmolar CPB prime was used.

RESULTS: Analyses of the perioperative plasma osmolality on eight occasions gave the following results: the preoperative osmolality level was normal (297±4 mOsm/kg); a significant increase to 322±17 mOsm/kg (p<0.001) was observed at the commencement of CPB and remained elevated after 30 minutes (310±4 mOsm/kg) and throughout the procedure (309±4 mOsm/kg); the osmolality level returned to 291±5 mOsm/kg on day 1 postoperatively and remained normal the following day (291±6 mOsm/kg).

CONCLUSIONS: Use of hyperosmolar CPB prime resulted in a dramatic and instant elevation of the plasma osmolality. Rapid changes in plasma osmolality are associated with organ dysfunction (e.g. osmotic demyelination syndrome), therefore, effects on plasma osmolality related to the CPB prime composition should be recognised. Influence on organ function and clinical outcome warrants further investigations. - Clinical Trials.gov (NCT03060824). Changes in Plasma Osmolality Related to the Use of Cardiopulmonary Bypass With Hyperosmolar Prime. URL: https://clinicaltrials.gov/ct2/show/NCT03060824?term=cpb&cond=osmolality&rank=1.