Microvascular and systemic impact of resuscitation with pegylated carboxyhemoglobin-based oxygen carrier or hetastarch in a rat model of transient hemorrhagic shock.

BACKGROUND: Hemorrhage is the leading cause of preventable, traumatic death. Currently, pre-hospital resuscitation fluids provide preload but not oxygen carrying capacity-a critical blood function that mitigates microvascular ischemia and tissue hypoxia during hemorrhagic shock. Solutions containing polymerized hemoglobin have been associated with vasoactive and hypertensive events. A novel hemoglobin-based oxygen carrier, modified with PEGylation and CO moieties (PEG-COHb) may overcome these limitations. OBJECTIVES: To evaluate the systemic and microcirculatory effects of PEG-COHb as compared to the 6% hetastarch in a rat model of hemorrhagic shock. METHODS: Male Sprague Dawley rats (N = 20) were subjected to severe, controlled, hemorrhagic shock. Animals were randomized to 20% estimated blood-volume resuscitation with either 6% hetastarch or PEG-COHb. Continuous, invasive, cardiovascular measurements and arterial blood gases were measured. Microcirculatory measurements of interstitial oxygenation (PISFO2) and vasoactivity helped model oxygen delivery in the spinotrapezius muscle using intravital and phosphorescence quenching microscopy. RESULTS: Hemorrhage reduced mean arterial pressure (MAP), arteriolar diameter and PISFO2, and increased lactate 10-fold in both groups. Resuscitation with both PEG-COHb and hetastarch improved cardiovascular parameters. However, PEG-COHb treatment resulted in higher MAP (p \u3c 0.001), improved PISFO2 (14 [PEG-COHb] vs 5 [hetastarch] mmHg; p \u3c 0.0001), lower lactate post-resuscitation (p \u3c 0.01) and extended survival from 90 min to 142 minutes (p \u3c 0.001) as compared to the hetastarch group. CONCLUSIONS: PEG-COHb improved MAP PISFO2, lactate and survival time as compared to 6% hetastarch resuscitation. Importantly, hypertension and vasoactivity were not detected in response to PEG-COHb resuscitation supporting further investigation of this resuscitation strategy

Application of electronic medical record-derived analytics in critical care: Rothman Index predicts mortality and readmissions in surgical intensive care unit patients.

INTRODUCTION: The Rothman Index (RI) is an objective measurement of a patient\u27s overall condition, automatically generated from 26 variables including vital signs, laboratory data, cardiac rhythms, and nursing assessments. The purpose of this study was to assess the validity of RI scores in predicting surgical ICU (SICU) readmission rates and mortality. METHODS: We conducted a single-center retrospective analysis of surgical patients who were transferred from the SICU to the surgical floor from December 2014 to December 2016. Data included demographics, length of stay (LOS), mortality, and RI at multiple pretransfer and post-transfer time points. RESULTS: A total of 1,445 SICU patients were transferred to the surgical floor; 79 patients (5.5%) were readmitted within 48 hours of transfer. Mean age was 52 years, and 67% were male. Compared to controls, patients readmitted to the SICU within 48 hours experienced higher LOS (29 vs. 11 days, p \u3c 0.05) as well as higher mortality (2.5% vs. 0.6%, p \u3c 0.05). Patients requiring readmission also had a lower RI at 72, 48, and 24 hours before transfer as well as at 24 and 48 hours after transfer (p \u3c 0.05 for all). Rothman Index scores were categorized into higher-risk (65); RI scores at 24 hours before transfer were inversely proportional to overall mortality (RI \u3c 40 = 2.5%, RI 40-65 = 0.3%, and RI \u3e 65 = 0%; p \u3c 0.05) and SICU readmission rates (RI \u3c 40 = 9%, RI 40-65 = 5.2%, and RI \u3e 65 = 2.8%; p \u3c 0.05). Patients transferred with RI scores greater than 83 did not require SICU readmission within 48 hours. CONCLUSION: Surgical ICU patients requiring readmission within 48 hours of transfer have a significantly higher mortality and longer LOS compared to those who do not. Patients requiring readmission also have significantly lower pretransfer and post-transfer RI scores compared to those who do not. Rothman Index scores may be used as a clinical tool for evaluating patients before transfer from the SICU. Prospective studies are warranted to further validate use of this technology. LEVEL OF EVIDENCE: Retrospective database review, level III