High-flow oxygen therapy via nasal cannula (HFOTNASAL) increases airway pressure, ameliorates oxygenation and reduces work of breathing. High-flow oxygen can be delivered through tracheostomy (HFOTTRACHEAL), but its physiological effects have not been systematically described. We conducted a cross-over study to elucidate the effects of increasing flow rates of HFOTTRACHEAL on gas exchange, respiratory rate and endotracheal pressure and to compare lower airway pressure produced by HFOTNASAL and HFOTTRACHEAL. Twenty-six tracheostomized patients underwent standard oxygen therapy through a conventional heat and moisture exchanger, and then HFOTTRACHEAL through a heated humidifier, with gas flow set at 10, 30 and 50 L/min. Each step lasted 30 min; gas flow sequence during HFOTTRACHEAL was randomized. In five patients, measurements were repeated during HFOTTRACHEAL before tracheostomy decannulation and immediately after during HFOTNASAL. In each step, arterial blood gases, respiratory rate, and tracheal pressure were measured. During HFOTTRACHEAL, PaO2/FiO2 ratio and tracheal expiratory pressure slightly increased proportionally to gas flow. The mean [95% confidence interval] expiratory pressure raise induced by 10-L/min increase in flow was 0.2 [0.1–0.2] cmH2O (ρ = 0.77, p < 0.001). Compared to standard oxygen, HFOTTRACHEAL limited the negative inspiratory swing in tracheal pressure; at 50 L/min, but not with other settings, HFOTTRACHEAL increased mean tracheal expiratory pressure by (mean difference [95% CI]) 0.4 [0.3–0.6] cmH2O, peak tracheal expiratory pressure by 0.4 [0.2–0.6] cmH2O, improved PaO2/FiO2 ratio by 40 [8–71] mmHg, and reduced respiratory rate by 1.9 [0.3–3.6] breaths/min without PaCO2 changes. As compared to HFOTTRACHEAL, HFOTNASAL produced higher tracheal mean and peak expiratory pressure (at 50 L/min, mean difference [95% CI]: 3 [1–5] cmH2O and 4 [1–7] cmH2O, respectively). As compared to standard oxygen, 50 L/min of HFOTTRACHEAL are needed to improve oxygenation, reduce respiratory rate and provide small degree of positive airway expiratory pressure, which, however, is significantly lower than the one produced by HFOTNASAL.

Awake craniotomy (AC) is the preferred surgical option for intractable epilepsy and resection of tumors adjacent to or within eloquent cortical areas. Monitored anesthesia care (MAC) or an asleep-awake-asleep (SAS) technique is most widely used during AC. We used a random-effects modeled meta-analysis to synthesize the most recent evidence to determine whether MAC or SAS is safer and more effective for AC. We included randomized controlled trials and observational studies that explored the incidence of AC failure, duration of surgery, and hospital length of stay in adult patients undergoing AC. Eighteen studies were included in the final analysis. MAC was associated with a lower risk of AC failure when compared with SAS (global pooled proportion MAC vs. SAS 1% vs. 4%; odds ratio [ORs]: 0.28; 95% confidence interval [CI]: 0.11-0.71; P=0.007) and shorter surgical procedure time (global pooled mean MAC vs. SAS 224.44 vs. 327.94 min; mean difference, −48.76 min; 95% CI: −61.55 to −35.97; P<0.00001). SAS was associated with fewer intraoperative seizures (global pooled proportion MAC vs. SAS 10% vs. 4%; OR: 2.38; 95% CI: 1.05-5.39; P=0.04). There were no differences in intraoperative nausea and vomiting between the techniques (global pooled proportion MAC vs. SAS: 4% vs. 8%; OR: 0.86; 95% CI: 0.30-2.45; P=0.78). Length of stay was shorter in the MAC group (MAC vs. SAS 3.96 vs. 6.75 days; mean difference, −1.30; 95% CI: −2.69 to 0.10; P=0.07). In summary, MAC was associated with lower AC failure rates and shorter procedure time compared with SAS, whereas SAS was associated with a lower incidence of intraoperative seizures. However, there was a high risk of bias and other limitations in the studies included in this review, so the superiority of 1 technique over the other needs to be confirmed in larger randomized studies.

The recognition of trauma-induced coagulopathy (TIC) as an endogenous response to traumatic injuries rather than a consequence of therapeutic interventions has shifted the clinical approach toward an early and physiologically based hemostatic resuscitation. Prompt identification and correction of fibrinolysis and fibrinogen level derangements, dysregulated thrombin generation, and platelet dysfunction represent the cornerstones of the treatment strategies. Currently available viscoelastic hemostatic assays (VHAs) are point-of-care devices able to rapidly assess the phases of clot initiation, propagation, stabilization, and degradation, as well as isolate the contribution of specific elements—e.g., fibrinogen—to the coagulation process in fully automated analyses by multi-channel single-use cartridges. As a result, in the last decade, VHAs have been widely investigated as tools to implement individualized protocols of hemostatic resuscitation. Current guidelines support their use to optimize transfusion load in a goal-directed strategy. Nevertheless, contrasting evidence has emerged regarding the improvement in main clinical outcomes induced by the VHA-based algorithm of hemostatic resuscitation compared with those guided by conventional coagulation tests, and their place in the management of this peculiar population is still a matter of debate. We propose a narrative review ranging from TIC physiopathology as a proper substrate for viscoelastic diagnostic technique, through the strengths and weaknesses of VHAs, to their application in clinical practice.