Laurel Omert

The impact of hyperglycemia on patients with severe brain injury.

BACKGROUND This study aimed to analyze the relation of hyperglycemia to outcome in cases of severe traumatic brain injury, and to examine factors that may be responsible for the hyperglycemic state. METHODS A retrospective analysis in an intensive care unit of a level 1 trauma center investigated 77 patients with severe traumatic brain injury. Patients with a Glasgow Coma Scale (GCS) of 8 or lower who survived more than 5 days were reviewed. Serum glucose, base deficit, GCS, use of steroids, and amounts of insulin and carbohydrates were recorded for 5 days, along with age. The Injury Severity Score (ISS) and the Abbreviated Injury Score (AIS) for the head, chest, and abdomen also were recorded. A hyperglycemia score (HS) was calculated as follows. A value of 1 was assigned each day the glucose exceeded 170 mg/dL (range, 0-5). A hyperglycemia score for days 3, 4, and 5 (HS day 3-5) also was calculated (range, 0-3). Outcomes included mortality, day 5 GCS, intensive care unit length of stay, and hospital length of stay. RESULTS Of the 77 patients, 24 (31.2%) died. Nonsurvivors had higher glucose levels each day. The HS was higher for those who died: 2.4 +/- 1.7 versus 1.5 +/- 1.4 (p = 0.02). Univariate analysis showed that only HS and ISS correlated with all four outcome variables studied. Coxs regression analysis showed that mortality was related to age and ISS. Head AIS and HS were independent predictors of lower day 5 GCS, whereas HS 3-5 and day 4 GCS were related to prolonged hospital length of stay. Older age, diabetes, and lower day 1 GCS were associated with higher HS, whereas carbohydrate infusion rate, ISS, head AIS, and steroid administration were not. CONCLUSIONS Early hyperglycemia is associated with poor outcomes for patients with severe traumatic brain injury. Tighter control of serum glucose without reduction of nutritional support may improve the prognosis for these critically ill patients.

Harbingers of poor outcome the day after severe brain injury: hypothermia, hypoxia, and hypoperfusion.

BACKGROUND Traumatic brain injury (TBI) can be compounded by physiologic derangements that produce secondary brain injury. The purpose of this study is to elucidate the frequency with which physiologic factors that are associated with secondary brain injury occur in patients with severe closed head injuries and to determine the impact of these factors on outcome. METHODS The records of 81 adult blunt trauma patients with Glasgow Coma Scale scores < or = 8 and transport times < 2 hours to a Level I trauma center were retrospectively reviewed searching for the following 11 secondary brain injury factors (SBIFs) in the first 24 hours postinjury: hypotension, hypoxia, hypercapnia, hypocapnia, hypothermia, hyperthermia, metabolic acidosis, seizures, coagulopathy, hyperglycemia, and intracranial hypertension. We recorded the worst SBIF during six time periods: hours 1, 2, 3, 4, 5 to 14, and 16 to 24. Occurrence of each SBIF was then correlated with outcome. RESULTS Hypocapnia, hypotension, and acidosis occurred more frequently than other SBIFs (60-80%). Hypotension, hyperglycemia, and hypothermia were associated with increased mortality rate. Patients with episodes of hypocapnia, acidosis, and hypoxia had significantly longer intensive care unit length of stay (LOS). These three SBIFs and hyperglycemia related to longer hospital LOS as well. Hypotension and acidosis were associated with discharge to a rehabilitation facility rather than home. Finally, multivariate regression analysis revealed that hypotension, hypothermia, and Abbreviated Injury Scale score of the head were independently related to mortality, whereas other SBIFs, age, Injury Severity Score, and Glasgow Coma Scale score were not. Metabolic acidosis and hypoxia were related to longer intensive care unit and hospital LOS. CONCLUSION Our early management of head-injured patients stresses avoidance and correction of SBIFs at all costs. Nonetheless, SBIFs occur frequently in the first 24 hours after traumatic brain injury. Six of the 11 factors studied are associated with significantly worse outcomes. Hypotension and hypothermia are independently related to mortality. Because these SBIFs are potentially preventable, protocols could be developed to decrease their frequency.

Human Polymerized Hemoglobin for the Treatment of Hemorrhagic Shock when Blood Is Unavailable: The USA Multicenter Trial

BACKGROUND Human polymerized hemoglobin (PolyHeme, Northfield Laboratories) is a universally compatible oxygen carrier developed to treat life-threatening anemia. This multicenter phase III trial was the first US study to assess survival of patients resuscitated with a hemoglobin-based oxygen carrier starting at the scene of injury. STUDY DESIGN Injured patients with a systolic blood pressure</=90 mmHg were randomized to receive field resuscitation with PolyHeme or crystalloid. Study patients continued to receive up to 6 U of PolyHeme during the first 12 hours postinjury before receiving blood. Control patients received blood on arrival in the trauma center. This trial was conducted as a dual superiority/noninferiority primary end point. RESULTS Seven hundred fourteen patients were enrolled at 29 urban Level I trauma centers (79% men; mean age 37.1 years). Injury mechanism was blunt trauma in 48%, and median transport time was 26 minutes. There was no significant difference between day 30 mortality in the as-randomized (13.4% PolyHeme versus 9.6% control) or per-protocol (11.1% PolyHeme versus 9.3% control) cohorts. Allogeneic blood use was lower in the PolyHeme group (68% versus 50% in the first 12 hours). The incidence of multiple organ failure was similar (7.4% PolyHeme versus 5.5% control). Adverse events (93% versus 88%; p=0.04) and serious adverse events (40% versus 35%; p=0.12), as anticipated, were frequent in the PolyHeme and control groups, respectively. Although myocardial infarction was reported by the investigators more frequently in the PolyHeme group (3% PolyHeme versus 1% control), a blinded committee of experts reviewed records of all enrolled patients and found no discernable difference between groups. CONCLUSIONS Patients resuscitated with PolyHeme, without stored blood for up to 6 U in 12 hours postinjury, had outcomes comparable with those for the standard of care. Although there were more adverse events in the PolyHeme group, the benefit-to-risk ratio of PolyHeme is favorable when blood is needed but not available.

Role of the emergency medicine physician in airway management of the trauma patient.

BACKGROUND A Level I trauma center recently underwent a policy change wherein airway management of the trauma patient is under the auspices of Emergency Medicine (EM) rather than Anesthesiology. METHODS We prospectively collected data on 11 months of EM intubations (EMI) since this policy change and compared them to the last year of Anesthesia-managed intubations (ANI) to answer the following questions: (1) Is intubation of trauma patients being accomplished effectively by EM? (2) Has there been a change in complication rates since the policy change? (3) How does the complication rate at our trauma center compare with other institutions? RESULTS EM residents successfully intubated trauma patients on their first attempt 73.7% of the time compared with 77.2% ANI. The overall success rates, i.e., securing the airway within three attempts, were 97.0% (EMI) and 98.0% (ANI). The airway was successfully secured by EMI 100% of the time while a surgical airway was performed in two ANIs. CONCLUSION EM residents and staff can safely manage the airway of trauma patients. There is no statistically significant difference in peri-intubation complications. The complication rate for EDI (33%) and ANI (38%) is higher than reported in the literature, although the populations are not entirely comparable.

Neutrophil accumulation and damage to the gastric mucosa in resuscitated hemorrhagic shock is independent of inducible nitric oxide synthase.

Polymorphonuclear leukocytes (PMN) and inducible nitric oxide synthase (iNOS) appear to play important roles in the liver and in lung injury induced by hemorrhagic shock. Their precise roles in hemorrhagic shock-induced acute gastric mucosal lesions (AGML), however, are still poorly understood. In this study, we investigated the effect of neutropenia on hemorrhagic shock-induced AGML. We also examined the roles of iNOS in PMN infiltration into the mucosa and AGML during hemorrhagic shock by using L-N6-(1-iminoethyl)-lysine, a potent inhibitor of iNOS, and by reverse transcriptase polymerase chain reaction. Remarkable gastric mucosal damage occurs after hemorrhagic shock. PMN depletion caused by Vinblastine pretreatment significantly attenuates this AGML. Although low-dose L-N6-(1-iminoethyl)-lysine (50 microg/kg, iNOS inhibition) has no effect on AGML, high-dose L-N6-(1-iminoethyl)-lysine (250 microg/kg, iNOS + endothelial NOS inhibition) significantly exacerbates AGML without increasing PMN infiltration into the mucosa. The mRNA expression of iNOS in the stomach during hemorrhagic shock cannot be detected by reverse transcriptase polymerase chain reaction. We conclude that PMN play a pivotal role in hemorrhagic shock-induced AGML, iNOS does not regulate PMN infiltration into the mucosa, and endothelial NOS provides important protection against AGML during hemorrhagic shock.

Characteristics and outcomes of trauma patients with ICU lengths of stay 30 days and greater: a seven-year retrospective study

IntroductionProlonged intensive care unit lengths of stay (ICU LOS) for critical illness can have acceptable mortality rates and quality of life despite significant costs. Only a few studies have specifically addressed prolonged ICU LOS after trauma. Our goals were to examine characteristics and outcomes of trauma patients with LOS ≥ 30 days, predictors of prolonged stay and mortality.MethodsAll trauma ICU admissions over a seven-year period in a level 1 trauma center were analyzed. Admission characteristics, pre-existing conditions and acquired complications in the ICU were recorded. Logistic regression was used to identify independent predictors of prolonged LOS and predictors of mortality among those with prolonged LOS after univariate analyses.ResultsOf 4920 ICU admissions, 205 (4%) had ICU LOS >30 days. These patients were older and more severely injured. Age and injury severity score (ISS) were associated with prolonged LOS. After logistic regression analysis, sepsis, acute respiratory distress syndrome, and several infectious complications were important independent predictors of prolonged LOS. Within the group with ICU LOS >30 days, predictors of mortality were age, pre-existing renal disease as well as the development of renal failure requiring dialysis. Overall mortality was 12%.ConclusionsThe majority of patients with ICU LOS ≥ 30 days will survive their hospitalization. Infectious and pulmonary complications were predictors of prolonged stay. Further efforts targeting prevention of these complications are warranted.

Postinjury resuscitation with human polymerized hemoglobin prolongs early survival: a post hoc analysis.

Hemoglobin-based oxygen carriers (HBOCs) may be useful in the early treatment of hemorrhagic shock when stored blood is not available. In the recent Phase III USA multicenter trial using human polymerized hemoglobin (PolyHeme), patients with hemorrhagic shock were randomized to treatment with PolyHeme or crystalloid starting in the field. Subsequent therapy in the hospital included additional PolyHeme in the treatment group (up to six units or 300 gm hemoglobin) and red blood cells (RBCs) in both groups. Day 30 mortality was higher in the PolyHeme group but not significantly different (PolyHeme 13% [47 of 349]; Control 10% [35 of 365]; p 0.13).1 There were some baseline preinfusion differences between the treatment groups. The PolyHeme group had more pretreatment coagulopathy and more severely injured patients in the cohort with blunt mechanism. Despite the complexity of the population, failure to reach a predetermined 30-day mortality end point for noninferiority was the primary basis for the refusal of the US Food and Drug Administration to approve the biological license application for PolyHeme. There was also concern about a higher incidence of adverse events (AEs) and serious adverse events (SAEs) in the PolyHeme recipients. Since the publication of these results, a number of questions have been raised about the appropriateness of day 30 mortality as the primary end point and the confounding influence of RBC transfusions given to both groups of patients on the analysis of safety and efficacy. This report describes several post hoc subgroup analyses. The purpose of these subgroup analyses is to examine time to death and determine whether early survival is an important end point of resuscitation with PolyHeme and to scrutinize safety data in groups of patients treated similarly. Specifically, we address the following questions: Y Which patients may have benefited from early administration of PolyHeme, and how might that benefit be extrapolated to the intended population?

A role of neutrophils in the down-regulation of IL-6 and CD14 following hemorrhagic shock

ABSTRACT Hemorrhagic shock (HS) followed by resuscitation has been shown to initiate a series of events, including local cytokine production and PMN accumulation. To determine whether PMN are involved in the regulation of IL-6 expression in the liver or lungs, IL-6 mRNA levels were measured in rats made neutropenic by vinblastine pretreatment prior to HS. IL-6 mRNA levels were determined at 4 or 24 h following resuscitation from shock. Vinblastine alone in normal rats or sham-treated rats had no effect at 4 or 24 h. Vinblastine pretreatment had no effect on the HS-induced increase in IL-6 mRNA at 4 h but dramatically increased levels in both liver and lung at 24 h. Peripheral PMN counts were reduced by 95% in all vinblastine-treated animals. Similar changes seen in CD14 mRNA expression indicate that these effects are not limited to IL-6. These data show that normal PMN levels are not needed for induction of IL-6 and CD14 in HS, and suggest that PMN accumulation down-regulates the expression of these genes.

Continuous arteriovenous hemofiltration with dialysis (CAVH-D): An alternative to hemodialysis in the mass casualty situation☆

Renal failure is a common sequela of mass casualty, particularly when crush injury is involved. Traditional management of renal failure with hemodialysis equipment may be difficult or inaccessible due to lack of electricity and water supply or damage to existing equipment. Furthermore, a sudden new population of renal failure patients may overwhelm an existing dialysis program. The rapid mobilization of traditional hemodialysis equipment may be delayed due to limited supply, manufacturing delays, or inventory shortages. For these reasons, we propose the use of continuous arteriovenous hemofiltration with dialysis (CAVH-D) as an alternative renal support modality for the mass casualty situation.

Asymptomatic aortic stenosis and unexpected death in the trauma patient

We report the cases of two young trauma patients with asymptomatic aortic stenosis who died after nonlethal blunt traumatic injuries. In both cases, their deaths were attributed to their underlying valvular disease. Awareness of the incidence of asymptomatic aortic stenosis and its potential physiologic hazard to the trauma victim may facilitate management of these difficult patients.