Recent advances in cerebral oximetry : assessment of cerebral autoregulation with near-infrared spectroscopy : myth or reality?

In recent years, the feasibility of near-infrared spectroscopy to continuously assess cerebral autoregulation has gained increasing interest. By plotting cerebral oxygen saturation over blood pressure, clinicians can generate an index of autoregulation: the cerebral oximetry index (COx). Successful integration of this monitoring ability in daily critical care may allow clinicians to tailor blood pressure management to the individual patient’s need and might prove to be a major step forward in terms of patient outcome

An assessment of computer-assisted personalized sedation: a sedation delivery system to administer propofol for gastrointestinal endoscopy

Background: Demand for colonoscopy and EGD procedures is increasing. Impediments to performing these examinations persist, Patients perceive these procedures as unpleasant and painful. The use of suboptimal sedatives results in inefficiency in endoscopy practices. Improving sedation methods utilizing precise control of preferred sedatives may increase patient satisfaction ancl practice efficiency Objective: Our purpose was to demonstrate the feasibility of computer-assisted personalized sedation (CAPS) for facilitating the precise administration of propofol by endoscopist/nurse teams, achieving minimal to moderate sedation in subjects undergoing routine endoscopies. Design: Open label, single-center studies. Setting: Endoscopy clinics in Charlottesville, Virginia, and Gent, Belgium. Subjects: Twenty-four adults per center; 12 colonoscopies, 12 EGDs. Interventions: Propofol sedation with CAPS by endoscopist/registered nurse care teams. Main Outcome Measurements: Sedation level measured by modified observer's assessment of alertness/sedation (MOAA/S), recovery time measured from endoscope removal until Adrete >= 12, dosage of propofol, oxygen saturation, and safety assessments. Results: Subjects responded to mild tactile and verbal stimuli MOAA/S = 5, 4, 3, or 2) 99% of the time. Mean propofol closes in the United States and Belgium were 65.4 ancl 72.1 mg, respectively mean recovery times were 29 and 10 seconds, respectively. Oxygen desaturation occurred in only 6% of subjects. No device-related adverse events occurred. Limitation: Open-label design. Conclusions: Using CAPS, the endoscopist/nurse teams precisely controlled the administration of propofol achieving minimal to moderate sedation in subjects undergoing colonoscopy and EGD procedures. Mean propofol dosage was low and post-procedure recovery times were rapid. The device performed well when operated by the endoscopist/nurse team, with no device-related adverse events

Different patterns of cerebral and muscular tissue oxygenation 10 years after coarctation repair

The purpose of this study was to assess whether the lower exercise tolerance in children after coarctation repair is associated with alterations in peripheral tissue oxygenation during exercise. A total of 16 children after coarctation repair and 20 healthy control subjects performed an incremental ramp exercise test to exhaustion. Cerebral and locomotor muscle oxygenation were measured by means of near infrared spectroscopy. The responses of cerebral and muscle tissue oxygenation index (cTOI, mTOI), oxygenated (O(2)Hb), and deoxygenated hemoglobin (HHb) as a function of work rate were compared. Correlations between residual continuous wave Doppler gradients at rest, arm-leg blood pressure difference and local oxygenation responses were evaluated. Age, length, and weight was similar in both groups. Patients with aortic coarctation had lower peak power output (Ppeak) (72.3 +/- 20.2% vs. 106 +/- 18.7%, P < 0.001), VO(2)peak/kg (37.3 +/- 9.1 vs. 44.2 +/- 7.6 ml/kg, P = 0.019) and %VO(2)peak/kg (85.7 +/- 21.9% vs. 112.1 +/- 15.5%, P < 0.001). Cerebral O(2)Hb and HHb had a lower increase in patients vs. controls during exercise, with significant differences from 60 to 90% Ppeak (O(2)Hb) and 70% to 100% Ppeak (HHb). Muscle TOI was significantly lower in patients from 10 to 70% Ppeak and muscle HHb was significantly higher in patients vs. controls from 20 to 80% Ppeak. Muscle O(2)Hb was not different between both groups. There was a significant correlation between residual resting blood pressure gradient and Delta muscle HHb/Delta P at 10-20W and 20-30W (r = 0.40, P = 0.039 and r = 0.43, P = 0.034). Children after coarctation repair have different oxygenation responses at muscular and cerebral level. This reflects a different balance between O-2 supply to O-2 demand which might contribute to the reduced exercise tolerance in this patient population