Awake craniotomy using dexmedetomidine and scalp blocks: a retrospective cohort study.

PURPOSE: Anesthetic and surgical considerations for awake craniotomy (AC) include airway patency, patient comfort, and optimization of real-time brain mapping. The purpose of this study is to report our experience of using dexmedetomidine and scalp blocks, without airway intervention, as a means to facilitate and optimize intraoperative brain mapping and brain tumour resection during AC. METHODS: We conducted a retrospective cohort study of 55 patients who underwent AC from March 2012 to September 2016. The incidence of critical airway outcomes, perioperative complications, and successful intraoperative mapping was determined. The primary outcome was the incidence of a failed AC anesthetic technique as defined by the need to convert to general anesthesia with a secured airway prior to (or during) brain mapping and brain tumour resection. Secondary outcomes were the intraoperative incidence of: 1) altered surgical management due to information acquired through real-time brain mapping, 2) interventions to restore airway patency or rescue the airway, 3) hemodynamic instability (> 20% from baseline), 4) nausea and vomiting, 5) new onset neurologic deficits, and 6) seizure activity. RESULTS: There were no anesthesia-related critical events and no patients required airway manipulation or conversion to a general anesthetic. Multimodal language, motor, and sensory assessment with direct cortical electrical stimulation was successfully performed in 100% of cases. In 24% (13/55) of patients, data acquired during intraoperative brain mapping influenced surgical decision-making regarding the extent of tumour resection. Nine (16%) patients had intraoperative seizures. CONCLUSIONS: Dexmedetomidine-based anesthesia and scalp block facilitated AC surgery without any requirement for urgent airway intervention or unplanned conversion to a full general anesthetic. This approach can enable physiologic testing before and during tumour resection facilitating real-time surgical decision-making based on intraoperative brain mapping with patients awake thereby minimizing the risk of neurologic deficit and increasing the opportunity for optimal surgical resection.

Availability and use of capnography for in-hospital cardiac arrests in the United Kingdom.

BACKGROUND: Airway complications occur more frequently outside the operating theatre and in emergency situations. Capnography remains the gold standard for confirming correct endotracheal tube placement, retaining high sensitivity and specificity in cardiac arrest. The 2010 European Resuscitation Council guidelines for adult advanced life support recommended waveform capnography in this setting. We investigated current UK practice relating to the availability and use of this technology during cardiac arrest. METHODS: Between June and November 2014, a study was conducted of all UK acute hospitals with both a level three adult intensive care unit (ICU) and an emergency department (ED). A telephone questionnaire was administered examining intubation practice and utilisation of capnography within the ED, ICU and general wards. RESULTS: Two hundred and eleven hospitals met the inclusion criteria. The response rate was 100%. Arrests were mainly attended by anaesthesia (48%) and ICU physicians (38%) of registrar grade (56%). The ability to measure end tidal carbon dioxide (ETCO2) was available in all but 4 EDs; most used in waveform devices. Most ICUs were similar. However, in 67% of hospitals surveyed, it was not possible to measure ETCO2 in general wards. Where available, 87% used capnography to confirm ETT placement with less than 50% using ETCO2 to determine CPR effectiveness and 8% to prognosticate. CONCLUSIONS: We believe this is the first study of its kind to fully investigate the availability and use of capnography during cardiac arrest throughout the hospital. Whilst equipment provision appears adequate in critical care areas, it is insufficient in general wards.

Thymic output, ageing and zinc.

The role of the thymus is vital for orchestration of T-cell development and maturation. With increasing age the thymus undergoes a process of involution which results in a reduction in thymic size, function and output. Until relatively recent it was not feasible to accurately measure the magnitude of age-related loss of thymic function. With the discovery of T-cell receptor excision circles (TRECs), which are the stable by-products of the newly generated T-cells, it is now possible to quantitatively measure the extent of thymic output. This review examines the available data on immune function and zinc deficiency and places them in the context of the aims of the ZINCAGE project which include the evaluation of the role played by zinc in maintaining thymic output in healthy elderly individuals.