Shock : molecular, cellular, and systemic pathobiological aspects and therapeutic approaches : the official journal the Shock Society, the European Shock Society, the Brazilian Shock Society, the International Federation of Shock Societies
-
We previously reported that measurements of muscle oxygen saturation (SmO2) and the compensatory reserve index (CRI) provided earlier indication of reduced central blood volume than standard vital signs (e.g., blood pressure, heart rate, arterial oxygen saturation). In the present study, we hypothesized that the CRI would provide greater sensitivity and specificity to detect progressive decrease in central circulating blood volume compared with SmO2. Continuous noninvasive measures of CRI (calculated from feature changes in the photoplethysmographic arterial waveforms) were collected from 55 healthy volunteer subjects before and during stepwise lower body negative pressure (LBNP) to the onset of hemodynamic decompensation. ⋯ In comparison, SmO2, [H], and HbT had significantly lower ROC AUC, sensitivity and specificity values for detecting the same outcome. Consistent with our hypothesis, CRI detected central hypovolemia with significantly greater specificity than measures of tissue metabolism. Single measurement of CRI may enable more accurate triage, while CRI monitoring may allow for earlier detection of casualty deterioration.
-
Humans are able to compensate for significant blood loss with little change in traditional vital signs. We hypothesized that an algorithm, which recognizes compensatory changes in photoplethysmogram (PPG) waveforms, could detect active bleeding and ongoing volume loss in injured patients. ⋯ A novel computational algorithm that recognizes subtle changes in PPG waveforms can quickly and noninvasively discern which patients are actively bleeding and continuing to bleed with high sensitivity and specificity in acutely injured patients.
-
Shock index (SI) (heart rate [HR]/systolic blood pressure [SBP]) has been used to predict outcome in both adult and pediatric sepsis within the intensive care unit (ICU). We aimed to evaluate the utility of SI before pediatric ICU (PICU) admission. ⋯ The absolute or change in SI does not predict early death any more than HR and SBP individually in children with sepsis.
-
Hemorrhage is the leading cause of preventable death in trauma, and hemorrhage from noncompressible junctional anatomic sites is particularly difficult to control. The current standard is QuikClot Combat Gauze packing, which requires 3 min of compression. We have created a novel dressing with calcium carbonate microparticles that can disperse and self-propel upstream against flowing blood. ⋯ PTG animals maintained lower serum lactate and higher hemoglobin concentrations than NPTG (P <0.05) suggesting PTG decreased severity of subsequent hemorrhagic shock. However, total blood loss, Lactated Ringer infusion volumes, and mean arterial pressures of surviving animals were not different between groups (P >0.05). Thus, in this swine model of junctional arterial hemorrhage, gauze with self-propelled, prothrombotic microparticles improved survival and 2 indicators of hemorrhagic shock when applied without compression, suggesting this capability may enable better treatment of non-compressible junctional wounds.
-
Non-shockable rhythms represent an increasing proportion of reported cases of out-of-hospital cardiac arrest but with an associated poor prognosis. In the present study, we investigated the effects of hydrogen inhalation on cardiac and neurological function after cardiopulmonary resuscitation and compared the therapeutic benefit with hypothermia in an asphyxial rat model of cardiac arrest. ⋯ Small amounts of inhaled hydrogen were superior to mild hypothermia in improving cardiac function and neurological outcome in this asphyxial rat model of cardiac arrest.