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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 μg 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 μg kg−1 h−1) a significant decrease in the characteristic Parkinsonian subthalamic activity was observed (P 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 μg 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. Clinical trial registration EudraCT 2016-002680-34; NCT-02982512.

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

Background Deep brain stimulation electrodes can record oscillatory activity from deep brain structures, known as local field potentials. The authors’ objective was to evaluate and quantify the effects of dexmedetomidine (0.2 μg·kg-1·h-1) on local field potentials in patients with Parkinson disease undergoing deep brain stimulation surgery compared with control recording (primary outcome), as well as the effect of propofol at different estimated peak effect site concentrations (0.5, 1.0, 1.5, 2.0, and 2.5 μg/ml) from control recording. Methods A nonrandomized, nonblinded controlled clinical trial was carried out to assess the change in local field potentials activity over time in 10 patients with Parkinson disease who underwent deep brain stimulation placement surgery (18 subthalamic nuclei). The relationship was assessed between the activity in nuclei in the same patient at a given time and repeated measures from the same nucleus over time. Results No significant difference was observed between the relative beta power of local field potentials in dexmedetomidine and control recordings (−7.7; 95% CI, −18.9 to 7.6). By contrast, there was a significant decline of 12.7% (95% CI, −21.3 to −4.7) in the relative beta power of the local field potentials for each increment in the estimated peak propofol concentrations at the effect site relative to the control recordings. Conclusions Dexmedetomidine (0.2 μg·kg-1·h-1) did not show effect on local field potentials compared with control recording. A significant deep brain activity decline from control recording was observed with incremental doses of propofol.

Deep brain stimulation electrodes can record oscillatory activity from deep brain structures, known as local field potentials. The authors' objective was to evaluate and quantify the effects of dexmedetomidine (0.2 μg·kg·h) on local field potentials in patients with Parkinson disease undergoing deep brain stimulation surgery compared with control recording (primary outcome), as well as the effect of propofol at different estimated peak effect site concentrations (0.5, 1.0, 1.5, 2.0, and 2.5 μg/ml) from control recording.A nonrandomized, nonblinded controlled clinical trial was carried out to assess the change in local field potentials activity over time in 10 patients with Parkinson disease who underwent deep brain stimulation placement surgery (18 subthalamic nuclei). The relationship was assessed between the activity in nuclei in the same patient at a given time and repeated measures from the same nucleus over time.No significant difference was observed between the relative beta power of local field potentials in dexmedetomidine and control recordings (-7.7; 95% CI, -18.9 to 7.6). By contrast, there was a significant decline of 12.7% (95% CI, -21.3 to -4.7) in the relative beta power of the local field potentials for each increment in the estimated peak propofol concentrations at the effect site relative to the control recordings.Dexmedetomidine (0.2 μg·kg·h) did not show effect on local field potentials compared with control recording. A significant deep brain activity decline from control recording was observed with incremental doses of propofol.

The PiCCO™ monitor (Pulsion Medical System, Melsungen, Hessen, Germany) has become an alternative method of haemodynamic invasive monitoring for the critically ill patient. The determination of the continuous cardiac output by arterial pulse contour analysis requires the periodic calibration of the monitor. This calibration is performed by the injection of a bolus of 15–20 ml cold saline through a central line catheter [1-3]. We present the case of a 54-year-old woman with breast cancer who underwent cord decompression surgery for bone metastasis. On the seventh postoperative day she developed multiorgan system failure (septic shock + respiratory insufficiency + acute renal failure + disseminated intravascular coagulopathy) due to nosocomial pneumonia. The patient was admitted to the intensive care unit and the PiCCO™ monitor was used for invasive haemodynamic monitoring. A Certofix™ Trio HF catheter (Braun, Munich, Bayern, Germany) was placed uneventfully in the right internal jugular vein to carry out continuous venous–venous haemodialysis (CVVH-D). The Certofix™ Trio HF is a triplelumen catheter made of polyurethane with three lumens (first channel, distal = 16 G; second channel, middle = 12 G; and third channel, proximal = 12 G). The distal lumen was used for the calibrations of the PiCCO™ monitor due to the highrisk of insertion of another central line in a patient with severe coagulopathy. The analysis of the area under the thermodilution curve showed a hypodynamic state that was treated