High-level evidence is not yet available to guide dosage of LA used in regional blocks in children. The ASRA/ESRA recommendations intend to provide guidance in order to reduce the large variability of LA dosage currently observed in clinical practice.

These consensus guidelines have been developed by a group of Latin American experts in pain management, to point out patterns and make practical recommendations to guide the diagnosis, identify warning signs (yellow and red flags), and establish comprehensive medical management (pharmacologic and nonpharmacologic treatment) and monitoring plans for patients enduring neuropathic pain. From the viewpoint of pharmacologic management, drugs are classified into groups according to efficacy, availability/accessibility, and safety criteria. Drugs are recommended for use depending on the disease and particular circumstances of each patient, with an approach that favors multimodal treatment while taking into consideration the idiosyncrasies of medical practice in Latin America.

The ultrastructural anatomy of the human pia mater, such as pial cells, membrane thickness, and subpial tissue at different levels of the thoracic and lumbar spinal cord and nerve roots, was studied by special staining techniques, immunohistochemistry, and transmission and scanning electron microscopy. Fenestrations were found in samples at the thoracic-lumbar junction, conus medullaris, and nerve root levels. No fenestrations were found in samples at the thoracic level. At present, we cannot determine the significance of these findings.

The subdural space was not seen under transmission electron microscopy in samples of human spinal meninges where surgical manipulation was avoided. Scanning electron microscopy in other samples showed the presence of broken neurothelial cells giving up fissures that extended along the dura-arachnoid interface. These findings may explain the origin of a real subdural space.

Cancer causes considerable suffering and 80% of advanced cancer patients experience moderate to severe pain. Surgical tumor excision remains a cornerstone of primary cancer treatment, but is also recognized as one of the greatest risk factors for metastatic spread. The perioperative period, characterized by the surgical stress response, pharmacologic-induced angiogenesis, and immunomodulation results in a physiologic environment that supports tumor spread and distant reimplantation.In the perioperative period, anesthesiologists may have a brief and uniquewindow of opportunity to modulate the unwanted consequences of the stressresponse on the immune system and minimize residual disease. This reviewdiscusses the current research on analgesic therapies and their impact ondisease progression, followed by an evidence-based evaluation of perioperativepain interventions and medications.