Blood Gas Monitoring with Optodes

Point of care testing in Critical Care Medicine: the clinician's view

During the later years, Critical Care Medicine (CCM) has seen a rise in the possibilities of performing biochemical analyses at the point of care, or even continuous monitoring of biochemical variables. In general, point of care testing (POCT) is advantageous, by decreasing Therapeutic Turnaround Time, number of errors, and by reduction of blood-volume lost for analyses. Though not much evidence exist to prove beneficial effects with respect to early diagnostic accuracy, decrease in length of stay in Intensive Care Unit (ICU), decrease of costs, or decreased morbidity/mortality, clinicians in general agree that POCT is a prerequisite for early recognition of life-threatening conditions, and for titration of commonly applied therapies. Limitations in POCT include staff-dissatisfaction, diminished analytical accuracy, just as POCT-data must be integrated in the patients' medical record and the institutional information systems. Finally, POCT may induce economical stress, depending on many variables. All together, a strong, multidisciplinary, interdepartmental team-approach seems necessary to ensure cost-effectiveness. At present, POCT is not a replacement for conventional laboratory services in CCM, but a supplement. Before POCT can be introduced on a larger scale in CCM we must prove it reliable, consistent and cost-beneficial in order to avoid spreading of technology that provides more data and costs than true information and benefit.

Monitoring of Organ Dysfunction in Sepsis/Systemic Inflammatory Response Syndrome: Novel Strategies

Abstract. Sepsis and systemic inflammatory response syndrome—induced severe disruption of microcirculation and consecutive tissue hypoxia is considered a key factor in the development of organ dysfunction and multiple organ failure. The conventionally measured global variables such as lactate or macrohemodynamic parameters using a pulmonary artery catheter do not adequately mirror microcirculatory disturbances. Evaluation of the severity of microcirculatory distress and the effectiveness of resuscitation strategies requires new clinical technologies aimed at the microcirculation. It is anticipated that novel techniques such as optical spectroscopy and intelligent biosensors will play a major role in the development of new monitoring systems. In general, the current monitoring of organ dysfunction is characterized by a trend from invasive to noninvasive and “safe” techniques, which provide bedside or even on-line monitoring and allow a more precise and earlier detection of organ dysfunction. Techniques for the assessment of regional perfusion and microcirculatory bioenergetics to direct therapeutic procedures are expected to refine and optimize clinical treatment of critically ill patients in the future. This article addresses the question of which variables should be monitored, what is feasible, and what is valid for therapeutic consequences. Recent developments in monitoring of macro- and microcirculation and organ-specific dysfunction, e.g., lung, kidney, are described with respect to their advantages and limitations, and future directions are outlined.