Closed-loop systems for drug delivery

An updated review of mesoporous carbon as a novel drug delivery system

The nanotechnology approach has been recently adopted to provide more reliable, effective, controlled, and safe drug delivery systems. Nanostructured materials have gained great interest, including siliceous and carbonaceous nanoparticles. The effectiveness of mesoporous carbon nanoparticles (MCNs) in tumor imaging, targeting, and treatment is urging for more future studies. MCNs possess superior properties such as their biocompatibility, large surface area, large pore volume, tunability, and more responsive behavior to internal and external release triggers. These outstanding features make MCNs more applicable for stimuli-responsive drug delivery than the conventional forms of mesoporous silica nanoparticles (MSNs) and other carbon nanoparticles. In this review, we outlined the latest updates regarding the safety, benefits, and potential applications of MCNs.

Closed-Loop Intravenous Drug Administration Using Photoplethysmography

An optically-based injection control system has been developed for preclinical use for an intravenous drug delivery application. Current clinical drug delivery for oncology typically provides for intravenous administration without an awareness of achieved plasma concentration, yet interpatient variability produces consequences ranging from toxicity to ineffectual treatments. We report a closed-loop injection system integrating a pulse-photoplethysmograph to measure the concentration of an injected agent in the circulating blood system using a previously described technique. A proportional-derivative (PD) controller manages the injection rate in real-time. The target function for the controller is the population estimate of the pharmacokinetic model developed using Bayesian statistics describing the injection phase of a calibration set of 22 injections in mice. The controlled set of eight injections showed a reduction in variance from the target injection phase concentration profile of 74.8%.

Decision support for hemodynamic management: from graphical displays to closed loop systems

The way hemodynamic therapies are delivered today in anesthesia and critical care is suboptimal. Hemodynamic variables are not always understood correctly and used properly. The adoption of hemodynamic goal-directed strategies, known to be clinically useful, is poor. Ensuring therapies are delivered effectively is the goal of decision support tools and closed loop systems. Graphical displays (metaphor screens) may help clinicians to better capture and integrate the multivariable hemodynamic information. This may result in faster and more accurate diagnosis and therapeutic decisions. Graphical displays (target screens) have the potential to increase adherence to goal-directed strategies and ultimately improve patients' outcomes, but this remains to be confirmed by prospective studies. Closed loop systems are the ultimate solution to ensure therapies are delivered. However, most therapeutic decisions cannot be based on a limited number of output variables. Therefore, one should focus on the development of systems designed to relieve clinicians from very simple and repetitive tasks. Whether intraoperative goal-directed fluid therapy may be one of these tasks remains to be evaluated.

Advanced technologies in trauma critical care management

Care of critically injured patients has evolved over the 50 years since Shoemaker established one of the first trauma units at Cook County Hospital in 1962. Modern trauma intensive care units offer a high nurse-to-patient ratio, physicians and midlevel providers who manage the patients, and technologically advanced monitors and therapeutic devices designed to optimize the care of patients. This article describes advances that have transformed trauma critical care, including bedside ultrasonography, novel patient monitoring techniques, extracorporeal support, and negative pressure dressings. It also discusses how to evaluate the safety and efficacy of future advances in trauma critical care.

Sedation: not quite that simple

The number of diagnostic and therapeutic interventions performed under sedation is growing rapidly. While providing patients with an improved experience secondary to anxiolysis, analgesia, and amnesia, sedation also puts them at risk for associated cardiorespiratory and other complications. Several medications are available for sedation, all of which have unique advantages and disadvantages. The combination of patient characteristics, procedural factors, and side effects associated with each medication places each patient at risk and therefore, vigilance during sedation cannot be overemphasized. Due vigilance includes proper monitoring, training, staffing, and equipment, all of which are essential to the safe delivery of sedation.