Use of Near-Infrared Spectroscopy in Early Determination of Irreversible Hemorrhagic Shock

Abstract

Progression to irreversible shock may not be clinically apparent until a patient has been given several liters of fluids as well as multiple units of blood and blood products. In combat situations or in situations in which fluids for resuscitation are limited, resources need to be appropriately allocated. Therefore, early differentiation between patients who will progress to irreversible shock and those who are resuscitatable is important. We investigated whether the use of near-infrared spectroscopy (NIRS) in hemorrhage and resuscitation could assist in early detection of irreversible hemorrhagic shock. An established porcine model of hemorrhagic shock was used for experimentation. Twenty animals were treated with the same protocol including sedation and mechanical ventilation followed by instrumentation with a pulmonary artery catheter, arterial catheter, inferior vena cava (IVC) cannula, and placement of NIRS probes on the liver surface (during laparotomy), stomach (via modified nasogastric tube), and hind limb surface (skeletal muscle monitoring). Hemorrhagic shock was induced by removal of 35% blood volume via IVC cannula. Animals remained in shock for 90 minutes after which resuscitation was promptly initiated using lactated Ringer's solution (20 cc/kg) in a stepwise fashion of four fluid boluses. Hemodynamic and NIRS variables were measured at baseline, every 30 minutes during shock, and after each resuscitative step. NIRS measurements of tissue oxyhemoglobin saturation (StO2) in the liver, stomach, and hind limb were compared at all time points between animals that expired during resuscitation (unresuscitatable) and animals that survived all resuscitative steps (resuscitatable). All animals were similar with regard to body weight, volume hemorrhaged, and baseline hemodynamic and NIRS variables. After the first resuscitative step, both stomach and leg StO2 differed significantly between resuscitatable and unresuscitatable animals.

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Document Details

Document Type
Technical Report
Publication Date
Sep 01, 2004
Accession Number
ADA444889

Entities

People

  • Dean E. Myers
  • Greg J. Beilman
  • Jodie H. Taylor
  • Kristine E. Mulier

Organizations

  • University of Minnesota

Tags

DTIC Thesaurus Topics

  • Arteries
  • Blood
  • Blood Flow
  • Cardiovascular Physiological Phenomena
  • Health Services
  • Hemorrhage
  • Hemorrhagic Shock
  • Infrared Spectroscopy
  • Medical Personnel
  • Regression Analysis
  • Shock (Pathology)
  • Spectroscopy
  • Veins

Fields of Study

  • Medicine

Readers

  • Cardiovascular Physiology
  • Trauma or Military Medicine