Sodium Bicarbonate Facilitates Hemostasis in the Presence of Cerebrospinal Fluid Through Amplification of Platelet Aggregation.

Background: Appropriate hemostasis is essential for clear visualization of the neural structures and cleavage planes. It is also essential for avoiding heat-induced injury, minimizing blood loss, and reducing operative time.

Objective: To determine the role of cerebrospinal fluid (CSF) in platelet-dependent hemostasis during neurosurgery.

Methods: The amplification of aggregation, activation of integrin αIIbβ3, intrinsic and extrinsic coagulation pathways, and activation of signaling cascades in platelets were evaluated. For comparison, various concentrations of a commercially available artificial CSF solution (aCSF), an artificial CSF solution prepared by the authors, and normal saline (NS) were used. Differences between aCSF and NS in obtaining in vivo hemostasis were assessed by measuring the tail vein bleeding time in C57BL/6N mice.

Results: Platelet aggregation was directly amplified by the addition of aCSF through increased activation of integrin αIIbβ3, phosphatidylserine exposure, and P-selectin expression. However, the prothrombin time and activated partial thromboplastin time were not primarily related to coagulation activity with the addition of aCSF. Activation of Src kinase was related to platelet activation by aCSF. The elimination of sodium bicarbonate from aCSF and the addition of the selective inhibitor of the HCO3/Cl exchanger, 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid disodium salt, significantly inhibited platelet aggregation. The bleeding time in aCSF-treated mice was significantly shorter than that in NS-treated mice.

Conclusion: Sodium bicarbonate facilitates hemostasis through the amplification of platelet aggregation function. The existence of CSF and irrigation with aCSF provide better conditions for physiological hemostasis and they have the potential of improving hemostasis by bipolar coagulation or with irrigation during neuroendoscopic procedures.