Advances in the Approaches Using Peripheral Perfusion for Monitoring Hemodynamic Status

Abstract

Measures of peripheral perfusion can be used to assess the hemodynamic status of critically ill patients. By monitoring peripheral perfusion status, clinicians can promptly initiate life-saving therapy and reduce the likelihood of shock-associated death. Historically, abnormal perfusion has been indicated by the observation of pale, cold, and clammy skin with increased capillary refill time. The utility of these assessments has been debated given that clinicians may vary in their clinical interpretation of body temperature and refill time. Considering these constraints, current sepsis bundles suggest the need to revise resuscitation guidelines. New technologies have been developed to calculate capillary refill time in the hopes of identifying a new gold standard for clinical care. These devices measure either light reflected at the surface of the fingertip (reflected light), or light transmitted through the inside of the fingertip (transmitted light). These new technologies may enable clinicians to monitor peripheral perfusion status more accurately and may increase the potential for ubiquitous hemodynamic monitoring across different clinical settings. This review will summarize the different methods available for peripheral perfusion monitoring and will discuss the advantages and disadvantages of each approach.

Keywords: capillary refill time; hemodynamic status; medical device; monitoring; optics; peripheral perfusion; sepsis; shock.

Figure 1

Mechanism of the CRI monitoring device. The curve fitting the recovery phase of the TLI waveform is modeled as an exponential decay using the least squares method. CRI is measured as the time at which the fitting curve returns to 90% of baseline.