Clinical Research Directory

A Validation Study of the Lab Clasp Device: A Point of Care Sepsis Risk Monitor

The overall purpose of this study is to demonstrate the usability of a clinical-grade device in the form of a finger clasp similar to a pulse oximeter for monitoring lactate values, by comparing its performance in reading interstitial fluid lactate values against a known clinical standard in the form of venous lactate levels. Serum lactate measurements are used clinically as a measure of end-organ dysfunction and physiologic stress. Changes in lactate may indicate worsening infection in the setting of sepsis, drug toxicity for certain xenobiotics, or exercise tolerance in exercise physiology. Serum lactate cutoffs have been developed for various disease states and trigger a variety of medical decisions directed at managing the course of the disease. A common theme in the application of lactate measurements to understanding changes in physiology is the need to obtain venous blood to determine lactate. While point-of-care assays have been developed that improve the processing speed, there continues to be a need to obtain fingerstick blood or in most cases, venous blood. Obtaining venous blood for serum lactate requires an individual with phlebotomy skills, the processing capabilities of a laboratory to determine lactate concentrations, or the availability of point of care technology. An alternative method to measure lactate is to sample interstitial fluid which surrounds cells and tissues in the body. Obtaining interstitial fluid is potentially less invasive without the need for repeat phlebotomy or the presence of an indwelling intravenous catheter which can become complicated by infection. The analysis of interstitial fluid for glucose has been validated and is clinically utilized in continuous glucose monitors in individuals with diabetes. In this investigation, the investigators will utilize a novel device, the Lab Clasp to obtain interstitial fluid in a noninvasive method. The Lab Clasp is manufactured to resemble a finger pulse oximeter with additional onboard microfluidics channels that obtain a lactate concentration from interstitial fluid. This streamlined process of obtaining the point of care lactate measurements on demand allows for tasks like serial lactate measurements to be accomplished on a reliable schedule with less workload for nursing staff typically required to draw venous blood. Additionally, the portable and noninvasive nature of the Lab Clasp system may render it usable in facilities that lack skilled staff necessary to perform phlebotomy.

Submental Tissue Oxygenation and Arterial Lactate in Major Surgery

During major surgical procedures performed under general anesthesia, changes in blood flow and oxygen delivery to tissues may occur due to blood loss, hemodynamic fluctuations, and anesthesia-related physiological effects. These changes can lead to impaired tissue perfusion, which is commonly reflected by increased arterial lactate levels. However, lactate measurements are intermittent and may not detect early perfusion abnormalities. This prospective observational study aims to investigate the relationship between submental tissue oxygenation measured by near-infrared spectroscopy (NIRS), microvascular reactivity assessed by the vascular occlusion test, and arterial lactate levels during major surgery. Adult patients undergoing major abdominal, neurosurgical, or orthopedic procedures will be monitored intraoperatively using non-invasive NIRS techniques, while arterial blood gas analyses will be performed as part of routine clinical care. The study does not involve any changes to standard anesthesia or surgical management. All treatments and clinical decisions will be made by the responsible care team according to routine practice. By evaluating non-invasive indicators of tissue oxygenation and microvascular function, this study aims to improve the understanding of early intraoperative tissue perfusion changes and their association with metabolic markers.

The Lactate Project: Investigating the Impact of Lactate to Preserve Vital Organ Blood Supply and Function in Heart and Brain

The aim of the proposed study is to investigate the effect of increased plasma lactate concentrations on the heart and brain's metabolism of other energy sources, primarily glucose in the brain and glucose and FFA in the heart. The investigator hypothesize that: * An acute increase in lactate plasma concentration will decrease cerebral glucose uptake and increase cerebral blood flow * An acute increase in lactate plasma concentration will decrease palmitate and glucose uptake in the myocardium, and increase myocardial perfusion