RESUMO
BACKGROUND: There is a consensus on the importance of monitoring intracranial pressure (ICP) during neurosurgery, and this monitoring reduces mortality during procedures. Current knowledge of ICP and cerebrospinal fluid pulse pressure has been built thanks to more than two centuries of research on brain dynamics. METHODS: Articles and books were selected using the descriptors "ICP," "cerebrospinal fluid pulse," "monitoring," "Monro-Kellie doctrine," and "ICP waveform" in electronic databases PubMed, Lilacs, Science Direct, and EMBASE. RESULTS: Several anatomists and physiologists have helped clarify the patterns of intracranial volumes under normal and pathological conditions. Monro-Kellie doctrine was an important step in a story that is reconstructed in this article. Through documentary research, we report the contribution of important medical figures, such as Monro, Kellie, Abercrombie, Burrows, Cushing, Langfitt, Marmarou, and other physiologists and anatomists who left their marks on the history of Medicine. CONCLUSION: Understanding intracranial dynamics is an unfinished historical construction. Current knowledge is the result of two centuries of research that began with the investigations of Alexander Monro secundus.
RESUMO
Tranexamic acid (TXA) is one of the measures indicated to reduce bleeding and the need for volume replacement. However, data on risks and benefits are controversial. This study analyzes the effectivity and risks of using tranexamic acid in neurosurgery. We selected articles, published from 1976 to 2019, on the PubMed, EMBASE, Science Direct, and The Cochrane Database using the descriptors: "tranexamic acid," "neurosurgery," "traumatic brain injury," "subdural hemorrhage," "brain aneurysm," and "subarachnoid hemorrhage." TXA can reduce blood loss and the need for blood transfusion in trauma and spinal surgery. Despite the benefits of TXA, moderate-to-high doses are potentially associated with neurological complications (seizures, transient ischemic attack, delirium) in adults and children. In a ruptured intracranial aneurysm, the use of TXA can considerably reduce the risk of rebleeding, but there is weak evidence regarding its influence on mortality reduction. The TXA use in brain surgery does not present benefit. However, this conclusion is limited because there are few studies. TXA in neurosurgeries is a promising method for the maintenance of hemostasis in affected patients, mainly in traumatic brain injury and spinal surgery; nevertheless, there is lack of evidence in brain and vascular surgeries. Many questions remain unanswered, such as how to determine the dosage that triggers the onset of associated complications, or how to adjust the dose for chronic kidney disease patients.
