Comparison of 2 Automated Pupillometry Devices in Critically III Patients.

BACKGROUND: Automated pupillometry may help detect early cerebral disturbances in critically ill patients. It remains unclear whether different automated pupillometry devices can detect pupillary abnormalities with similar accuracy. The aim of this study was to compare the performance of 2 commercially available automated pupillometry devices-Neurolight Algiscan (NL) and NPi-200 (NP) versus standard pupillary light reflex (PLR) examination in an unselected cohort of critically ill patients. MATERIALS AND METHODS: This prospective study included all adult (>18 y) patients admitted to the intensive care unit of a university hospital over a 20-day period. Measurements were made consecutively with each method once during the intensive care unit stay in each patient. To assess sensitivity and specificity, we calculated areas under the curve of the receiver operating characteristic curve. RESULTS: A total of 112 patients were included in the study. There was a significant correlation between the 2 automated pupillometry devices for pupil size, constriction to light stimulation, and constriction velocity but not for pupillary latency. The mean bias for pupil size measured by the NL and the NP devices was -0.12 (limit of agreement [LoA], -1.29 to 1.06) mm, for pupil constriction -1.0% (LoA, -9.3% to 7.2%), and for latency 0.02 (LoA, -0.22 to 0.25) ms. There was a significant correlation between pupil size evaluated by clinical examination and that using the NL or NP. The areas under the curves for pupil constriction measured by NL and NP were 0.93 and 0.91, respectively, to detect clinically reactive pupils. CONCLUSIONS: Although there was a significant correlation between NL and NP values as well as with clinical examination of the PLR, the 2 devices were not always interchangeable, especially for the evaluation of pupillary latency.

Different routes and formulations of melatonin in critically ill patients. A pharmacokinetic randomized study.

BACKGROUND AND OBJECTIVES: Critically ill patients present reduced endogenous melatonin blood levels, and they might benefit from its exogenous supplementation. The aim of this research was to evaluate the feasibility of different routes of administration and drug formulations of melatonin. The efficiency of absorption was assessed as well as the adequacy in achieving and maintaining the physiological nocturnal blood peak. METHODS: Twenty-one high-risk critically ill patients were randomly assigned to receive melatonin either: (a) per os, as a standard tablet (ST-OS), (b) per os, as a suspension in solid lipid nanoparticles (SLN-OS) or c) transdermal (TD), by applying a jellified melatonin microemulsion (µE) on the skin (µE-TD). SLN-OS and µE-TD were lipid-based colloidal systems. The endogenous melatonin blood values were observed for 24 hours; subsequently, melatonin 3 mg was administered and pharmacokinetics was studied for 24 hours further. RESULTS: In both groups that received ST-OS and SLN-OS, the median time-to-peak blood concentration was 0.5 hours; however, the area under the curve (AUC) after administration of SLN-OS was significantly higher than after ST-OS (157386 [65732-193653] vs 44441 [22319-90705] pg/mL*hours, P = 0.048). µE-TD presented a delayed time-to-peak blood concentration (4 hours), a lower bioavailability (AUC: 3142 [1344-14573] pg/mL*hours) and reached pharmacological peak concentration (388 [132-1583] pg/mL). CONCLUSIONS: SLN-melatonin enterally administered offers favourable pharmacokinetics in critically ill patients, with higher bioavailability with respect to the standard formulation; µE-TD provided effective pharmacological blood levels, with a time-concentration profile more similar to the physiological melatonin pattern.