Background: The identification of factors associated with perioperative red blood cell (RBC) transfusion provides an opportunity to optimize the patient and surgical plan, and to guide perioperative crossmatch and RBC orders. We examined the association among potential bleeding risk factors and RBC requirements to develop a novel predictive model for RBC transfusion in patients undergoing brain tumor surgery. Methods: This retrospective study included 696 adults who underwent brain tumor surgery between 2008 and 2018. Multivariable logistic regression with backward stepwise selection for predictor selection was used during modeling. Model performance was evaluated using area under the receiver operating characteristic curve, and calibration was evaluated with Hosmer-Lemeshow goodness-of-fit ¿2-estimate. Results: Preoperative hemoglobin level was inversely associated with the probability of RBC transfusion (odds ratio [OR]: 0.50; 95% confidence interval [CI]: 0.39-0.63; P<0.001). The need for RBC transfusion was also greater in patients who had a previous craniotomy (OR: 2.71; 95% CI: 1.32-5.57; P=0.007) and in those with larger brain tumor volume (OR: 1.01; 95% CI: 1.00-1.02; P=0.009). The relationship between number of planned craniotomy sites and RBC transfusion was not statistically significant (OR: 2.11; 95% CI: 0.61-7.32; P=0.238). A predictive model for RBC requirements was built using these 4 variables. The area under the receiver operating characteristic curve was 0.79 (95% CI: 0.70-0.87; P<0.001) showing acceptable calibration for predicting RBC transfusion requirements. Conclusions: RBC requirements in patients undergoing brain tumor surgery can be estimated with acceptable accuracy using a predictive model based on readily available preoperative clinical variables. This predictive model could help to optimize both individual patients and surgical plans, and to guide perioperative crossmatch orders.

A pseudocontinuous arterial spin labeling (PCASL) sequence combined with background suppression and single-shot accelerated 3D RARE stack-of-spirals was used to evaluate cerebrovascular reactivity (CVR) induced by breath-holding (BH) in ten healthy volunteers. Four different models designed using the measured change in PETCO2 induced by BH were compared, for CVR quantification. The objective of this comparison was to understand which regressor offered a better physiological model to characterize the cerebral blood flow response under BH. The BH task started with free breathing of 42 s, followed by interleaved end-expiration BHs of 21 s, for ten cycles. The total scan time was 12 min and 20 s. The accelerated readout allowed the acquisition of PCASL data with better temporal resolution than previously used, without compromising the post-labeling delay. Elevated CBF was observed in most cerebral regions under hypercapnia, which was delayed with respect to the BH challenge. Significant statistical differences in CVR were obtained between the different models in GM (p < 0.0001), with ramp models yielding higher values than boxcar models and between the two tissues, GM and WM, with higher values in GM, in all the models (p < 0.0001). The adjustment of the ramp amplitude during each BH cycle did not improve the results compared with a ramp model with a constant amplitude equal to the mean PETCO2 change during the experiment.

Background: Dexmedetomidine is frequently used for sedation during deep brain stimulator implantation in patients with Parkinson's disease, but its effect on subthalamic nucleus activity is not well known. The aim of this study was to quantify the effect of increasing doses of dexmedetomidine in this population. Methods: Controlled clinical trial assessing changes in subthalamic activity with increasing doses of dexmedetomidine (from 0.2 to 0.6 mg kg(-1) h(-1)) in a non-operating theatre setting. We recorded local field potentials in 12 patients with Parkinson's disease with bilateral deep brain stimulators (24 nuclei) and compared basal activity in the nuclei of each patient and activity recorded with different doses. Plasma levels of dexmedetomidine were obtained and correlated with the dose administered. Results: With dexmedetomidine infusion, patients became clinically sedated, and at higher doses (0.5-0.6 mg kg(-1) h(-1)) a significant decrease in the characteristic Parkinsonian subthalamic activity was observed (P<0.05 in beta activity). All subjects awoke to external stimulus over a median of 1 (range: 0-9) min, showing full restoration of subthalamic activity. Dexmedetomidine dose administered and plasma levels showed a positive correlation (repeated measures correlation coefficient=0.504; P<0.001). Conclusions: Patients needing some degree of sedation throughout subthalamic deep brain stimulator implantation for Parkinson's disease can probably receive dexmedetomidine up to 0.6 mg kg(-1) h(-1) without significant alteration of their characteristic subthalamic activity. If patients achieve a 'sedated' state, subthalamic activity decreases, but they can be easily awakened with a non-pharmacological external stimulus and recover baseline subthalamic activity patterns in less than 10 min.

Background During magnetic resonance-guided focused ultrasound for essential or parkinsonian tremor, adverse events (headache, nausea/vomiting, or anxiety) may alter the outcome of the procedure despite being mostly transient and mild. Objectives Our aim was to analyze the relationship between demographic, procedural, and anesthetic characteristics with magnetic resonance/ultrasound-related events. Methods This was a retrospective study at the Clinica Universidad de Navarra of patients undergoing thalamotomy with magnetic resonance-guided focused ultrasound between September 2018 and October 2019. The anesthesia protocol included headache and nausea/vomiting prophylaxis and rescue therapy. Dexmedetomidine was used for anxiolysis in some patients after thorough multidisciplinary assessment. Results A total of 123 patients were included. Headache was directly related to skull density ratio (P < 0.001) and skull thickness (P = 0.02). Patients with a skull density ratio less than 0.48 had 3 times the odds of experiencing moderate or severe headache (odds ratio [OR], 3.08; 95% confidence interval [CI], 1.21-7.82) and had a higher odds of aborting sonication due to pain. Sex was associated with increased nausea (P = 0.007). Women had 4 times the odds of nausea than men (OR, 4.4; 95% CI, 1.61-12.11). Dexmedetomidine did not reduce headache or nausea incidence. Patients who received dexmedetomidine had a higher number (P = 0.01) and total minutes of sonication (P = 0.01). Conclusions Patients with lower skull density ratios and higher skull thicknesses could benefit from an aggressive analgesic prophylaxis. Women are more likely to experience nausea. Dexmedetomidine did not reduce headache and nausea, but increased the number and duration of sonications. Its exact effect on tremor is still unclear.

We describe a Caucasian man in his late 60s who was admitted to the intensive care unit (ICU) with a history of cardiogenic shock secondary to an acute myocardial infarction. The patient's baseline serum creatinine levels were 0.9-1 mg/dL. On day 7 of the admission treatment with quetiapine was initiated due to a delirium episode. The next day the patient developed an erythematous-maculopapular rash and fever, with eosinophilia in the blood count. Over the following days the patient experienced an acute deterioration of kidney function requiring continuous renal replacement therapy. The skin lesions and eosinophilia resolved after withdrawal of quetiapine and systemic steroid therapy was administered. The patient was discharged from the ICU with a serum creatinine level of 2.6 mg/dL. Three months later, blood tests showed no recovery of the kidney function. According to the Naranjo adverse drug reaction probability scale, this event would be classified as 'probable' DRESS syndrome and, based on the RegiSCAR scoring system, was classified as 'definite' DRESS syndrome.

ObjectivesTo evaluate the relationship between pharmacokinetic descriptors of dexmedetomidine (predicted area under the curve during the procedure, predicted plasma level at the end of the procedure, and duration of procedure) and sedation depth (proportion of time with bispectral index <85 during the procedure) with recovery time after ambulatory procedures.Materials and methodsClinical observational study of patients undergoing oral and maxillofacial ambulatory surgery with dexmedetomidine as sole sedative agent. Patients received a loading dose of dexmedetomidine (0.25-1gkg(-1)) followed by a maintenance infusion (0.2-1.4gkg(-1)h(-1)) to keep a bispectral index <85 until 5min before the end of the procedure, and were transferred to a post-anesthesia care unit until criteria for discharge were met.ResultsData from 75 patients was analyzed. Sedation depth was directly associated with recovery time (Pearson correlation coefficient [r]=0.26; p=0.024). Around 7% of the variation in recovery time was explained by the proportion of time with bispectral index <85. No association with procedure duration (r=0.01; p=0.9), predicted area under the curve (r=0.1; p=0.4), or predicted plasma level of dexmedetomidine at the end of the procedure (r=0.12; p=0.3) with recovery time was observed.ConclusionsSedation depth with dexmedetomidine could play a role in increasing recovery time after oral and maxillofacial ambulatory surgery. In our study, the pharmacokinetic descriptors of dexmedetomidine did not seem to influence recovery time.Clinical relevanceSedation depth with dexmedetomidine could play a role in increasing recovery time after ambulatory procedures.

Introduction: Dexdor® do not include the possibility of loading dose, which could increase time to achieve adequate sedation for ambulatory procedures. The objective of this study was to evaluate the effect of several loading dose of dexmedetomidine in the time to achieve and maintain an optimal level of sedation and its clinical hemodynamic repercussion. Material and methods: The IRB approved this observational study for patients that underwent oral and maxillofacial ambulatory surgery under dexmedetomidine at the University of Navarra Clinic from February 2013 to November 2014. According to the loading dose the patients were grouped into 3 categories:<0.5, 0.5, and>0.5¿g/kg. Optimal level of sedation was defined as bispectral index<85. Data were analyzed using survival analysis techniques. Vasoactive drugs requirements was evaluated using exact logistic regression. Results: Eighty-one patients were evaluated. Hazard ratios for patients in 0.5 and >0.5¿g/kg loading dose categories for achieving a bispectral index<85 were 1.5 (95% CI 0.9, 2.6) and 1.8 (95% CI 0.8, 3.9), respectively, compared with the lowest category. Five patients (6.2%) required atropine for bradycardia. Patients in the group>0.5¿g/kg showed greater risk of requiring atropine compared with the group<0.5¿g/kg (odds ratio 2.2; 95% CI 0.03, 183). Conclusion: Loading dose of dexmedetomidine>0.5¿g/kg appears minimize the time to achieve and maintain an optimal level of sedation during the first 60min of procedure. Further investigation to elucidate the association between loading dose of dexmedetomidine and subsequent atropine requirements may be warranted.