1. A comparison of two doses of mannitol on brain relaxation during supratentorial brain tumor craniotomy: a randomized trial
- Author
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Monique Ruel, Marie-Pierre Sylvestre, Sonia Charbonneau, Alain Bouthilier, Robert Moumdjian, Charlotte Quentin, Marie-Pierre Fournier-Gosselin, Alexandre Lallo, Michel W. Bojanowski, and François Girard
- Subjects
Male ,Intracranial Pressure ,medicine.medical_treatment ,Supratentorial region ,Anesthesia, General ,Neurosurgical Procedures ,law.invention ,Electrolytes ,Randomized controlled trial ,law ,Medicine ,Humans ,Mannitol ,Diuretics ,Craniotomy ,Aged ,Surgical approach ,Relaxation (psychology) ,business.industry ,Brain Neoplasms ,Osmolar Concentration ,Hemodynamics ,Brain ,Supratentorial Neoplasms ,Middle Aged ,Anesthesiology and Pain Medicine ,medicine.anatomical_structure ,Treatment Outcome ,Anesthesia ,Sample Size ,Intracranial surgery ,Female ,Blood Gas Analysis ,business ,medicine.drug - Abstract
Twenty percent mannitol is widely used to reduce brain bulk and facilitate the surgical approach in intracranial surgery. However, a dose-response relationship has not yet been established. In this study, we compared the effects of 0.7 and 1.4 g·kg(-1) mannitol on brain relaxation during elective supratentorial brain tumor surgery.In this prospective, randomized, double-blind study, we enrolled 80 patients undergoing supratentorial craniotomy for tumor resection. Patients were assigned to receive 0.7 g·kg(-1) (group L) or 1.4 g·kg(-1) (group H) of 20% mannitol at surgical incision. Brain relaxation was assessed immediately after opening of the dura on a scale ranging from 1 to 4 (1 = perfectly relaxed, 2 = satisfactorily relaxed, 3 = firm brain, 4 = bulging brain).There was no significant difference between the 2 groups regarding age, sex, body mass index, and brain tumor localization or size. In group L 52.5% of patients and in group H 77.5% of patients presented a midline shift (P = 0.03). The median scores of brain relaxation (interquantile range) were 2.0 (1.75-3) and 2.0 (1-3) (P = 0.16 for patients in group L and H, respectively). We then used a proportional odds model to adjust for this unbalanced distribution and to assess the group effect (low-dose versus high-dose mannitol) on brain relaxation scores. When adjusted for the presence of midline shift, the use of a higher dose of mannitol resulted in an odds ratio of 2.5 (P = 0.03). This indicates that, considering the effect of a midline shift, the odds of having a 1-level improvement in relaxation score in patients who received a higher dose of mannitol (group H) was 2.5 times as large as the odds for the low-dose group. The odds ratio of 0.29 (P = 0.007) for the midline shift indicates that its occurrence was associated with a higher probability of a lower relaxation score, on average.In this study, we show that 1.4 g·kg(-1) of 20% mannitol results in equivalent brain relaxation scores as 0.7 g·kg(-1) in patients undergoing craniotomy for supratentorial brain tumor. When corrected for the presence of midline shift, this study reveals that patients in the high-dose group had significantly more chances of obtaining a better relaxation score compared with the lower-dose group.
- Published
- 2013