Lightweight noninvasive trauma monitor for early indication of central hypovolemia and tissue acidosis: a review
Authors
Soller, Babs R.Zou, Fengmei
Ryan, Kathy L.
Rickards, Caroline A.
Ward, Kevin R.
Convertino, Victor A.
UMass Chan Affiliations
Department of AnesthesiologyDocument Type
Journal ArticlePublication Date
2012-08-01Keywords
AcidosisBlood Pressure
Heart Rate
Hemorrhage
Humans
Hypovolemia
Monitoring, Physiologic
Muscle, Skeletal
Spectroscopy, Near-Infrared
Wounds and Injuries
Anesthesiology
Metadata
Show full item recordAbstract
BACKGROUND: Hemorrhage is a major cause of soldier death; it must be quickly identified and appropriately treated. We developed a prototype patient monitor that noninvasively and continuously determines muscle oxygen saturation (SmO(2)), muscle pH (pHm), and a regional assessment of blood volume (HbT) using near-infrared spectroscopy. Previous demonstration in a model of progressive, central hypovolemia induced by lower body negative pressure (LBNP) showed that SmO(2) provided an early indication of impending hemodynamic instability in humans. In this review, we expand the number of subjects and provide an overview of the relationship between the muscle and sublingual microcirculation in this model of compensated shock. METHODS: Healthy human volunteers (n = 30) underwent progressive LBNP in 5-minute intervals. Standard vital signs, along with stroke volume (SV), total peripheral resistance, functional capillary density, SmO(2), HbT, and pHm were measured continuously throughout the study. RESULTS AND DISCUSSION: SmO(2) and SV significantly decreased during the first level of central hypovolemia (-15 mm Hg LBNP), whereas vital signs were later indicators of impending cardiovascular collapse. SmO(2) declined with SV and inversely with total peripheral resistance throughout LBNP. HbT was correlated with declining functional capillary density, suggesting vasoconstriction as a cause for decreased SmO(2) and subsequently decreased pHm. CLINICAL TRANSLATION: The monitor has been miniaturized to a 58-g solid-state sensor that is currently being evaluated on patients with dengue hemorrhagic fever. Early results demonstrate significant decreases in SmO(2) similar to those observed with progressive reductions in central blood volume. As such, this technology has the potential to (1) provide a monitoring capability for both nontraumatic and traumatic hemorrhage and (2) help combat medics triage casualties and monitor patients during lengthy transport from combat areas.Source
J Trauma Acute Care Surg. 2012 Aug;73(2 Suppl 1):S106-11. doi: 10.1097/TA.0b013e318260a928. Link to article on publisher's siteDOI
10.1097/TA.0b013e318260a928Permanent Link to this Item
http://hdl.handle.net/20.500.14038/25738PubMed ID
22847078Related Resources
Link to Article in PubMedae974a485f413a2113503eed53cd6c53
10.1097/TA.0b013e318260a928