Pharmacotechnological pitfalls of priming--possible source of microembolization during open heart surgery.
OBJECTIVE
Besides low mortality and morbidity rates in cardiac surgery, the associated cognitive dysfunction is the focus of interest. One possible reason is microembolisation.


RESULTS
The authors analysed the crystallogenesis in the calcium-containing prime, inspired by their observation that the fluid sometimes becomes turbid during the priming process. Lactated Ringer-based prime solutions were tested, adding mannitol, NaHCO(3), and heparin. The oxygenator was ventilated with compressed medical air. Samples were taken for dynamic light scattering particulate level analysis. The priming was furthermore modelled in the laboratory by mixing the components and then ventilating the mixture through with compressed air. Turbid solutions from the operating room contained 100-6500 nm crystals, while clear solutions contained 20-473 nm particles. In the model, continuous pH measurement showed pH 6.4-7.4 after blending the solutions, which then elevated the pH to 7.5-8.0 after ventilation with concomitant turbidity. The pH of the prime can be stabilized by the addition of ascorbic acid (1-2 mg/ml) and, also, the turbidity may be prevented.


CONCLUSIONS
Ventilating the lactated Ringer-based calcium-containing primes after blending is not advisible because of alkalization and crystallogenesis. Ascorbic acid stabilizes the pH and prevents crystallogenesis in the prime. Pre-bypass filtration is recommended.
Hejjel
Laszlo
L
Department of Cardiac Surgery, Heart Institute, Faculty of Medicine, University of Pécs, Hungary.
Szluka
Gabor
G
Göbölös
Laszlo
L
Szabados
Sandor
S
Varga
Tamas
T
Mayer
Klara
K
Devay
Attila
A
Foltan
Maik
M
Ugocsai
Peter
P
Philipp
Alois
A
D000468:Alkalies; D001205:Ascorbic Acid / Q000737:chemistry / Q000494:pharmacology; D002118:Calcium / Q000009:adverse effects / Q000737:chemistry; D006348:Cardiac Surgical Procedures; D002315:Cardiopulmonary Bypass / Q000009:adverse effects*; D003072:Cognition Disorders / Q000209:etiology / Q000517:prevention & control; D003460:Crystallization; D004617:Embolism / Q000209:etiology* / Q000517:prevention & control*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007552:Isotonic Solutions / Q000009:adverse effects* / Q000737:chemistry; D008833:Microcirculation; D009391:Nephelometry and Turbidimetry; D010316:Particle Size; D000077325:Ringer's Lactate
D000468:Alkalies; D007552:Isotonic Solutions; D000077325:Ringer's Lactate; D001205:Ascorbic Acid; D002118:Calcium