Effect of mannitol on platelet function during elective craniotomy in adult patients with brain tumor

Mannitol is used in the treatment of raised intracranial pressure (ICP). The aim of this study was to investigate whether mannitol (MAN) leads to a relevant deterioration in platelet function in routine neurosurgical procedures.

Thirty-eight patients undergoing elective craniotomy due to a brain tumor with elevated ICP were included. After induction of anesthesia a blood sample was taken (T1). The patients then received 1 g∙kg^-1 MAN within 30 minutes. The second blood sample (T2) was obtained 60 minutes after T1. Blood samples were examined by means of aggregometry (Multiplate^®; Roche, Basel, Switzertland) and PFA-100^® tests (Siemens Healthineers, Erlangen, Germany).

No patient had clinical signs of increased bleeding. We could not find any deterioration in the aggregometry using Multiplate^® (Roche), neither in the adenosine diphosphate (ADP), the arachidonic acid (ASPI), or the thrombin receptor activating protein (TRAP) test. PFA-100^® (Siemens Healthineers) closing times (cT) showed a significant prolongation between T1 and T2: collagen/adenosine diphosphate (COL/ADP) test 79 s [70/99] and 91 s [81/109]; P=0.002); collagen/epinephrine (COL/EPI) test 109 s [92/129] and 122 s [94/159]; P=0.0004). A subgroup analysis showed that the patients who received isotonic balanced infusions only, had no prolongation of cT, whereas the patients who received additionally gelatin solution had a significant prolongation. COL/ADP: 78 s [70/98] and 91 s [82/133]; P=0.0004). COL/EPI: test 111 s [92/128] and 127 s [103/146]; P=0.0026). Except for individual outliers, the measured values were in the normal range.

In this study, we found no clinically relevant deterioration of platelet function in neurosurgical patients with increased ICP after administration of MAN. Changes that occurred were all within normal ranges.