Retrospective analysis of the effects of hypocalcemia in severely injured trauma patients

BACKGROUND

It has been suggested that the Lethal Triad be modified to include hypocalcemia, coined as the Lethal Diamond. Hypocalcemia in trauma has been attributed to multiple mechanisms, but new evidence suggests that traumatic injury may result in the development of hypoCa independent of blood transfusion. We hypothesize that hypocalcemia is associated with increased blood product requirements and mortality.

METHODS

A retrospective study of 1,981 severely injured adult trauma patients from 2016 to 2019. Ionized calcium (iCa) levels were obtained on arrival and subjects were categorized by a threshold iCa level of 1.00 mmol/L and compared. Univariable and multivariable logistic regression analysis was performed.

RESULTS

The hypocalcemia (iCa <1.00 mmol/L) group had increased rate of overall (p = 0.001), 4-hr (p = 0.007), and 24-hr (p = 0.003) mortality. There was no difference in prehospital transfusion volume between groups (p = 0.25). Hypocalcemia was associated with increased blood product requirements at 4 h (p <0.001), 24 h (p <0.001), and overall hospital length of stay (p <0.001). Logistic regression analysis showed increased odds of 4-hour mortality (OR 0.077 [95 % CI 0.011, 0.523], p = 0.009) and 24-hour mortality (OR 0.121 [95 % CI 0.019, 0.758], p = 0.024) for every mmol/L increase in iCa.

CONCLUSIONS

This study shows the association of hypoCa and traumatic injury. Severe hypoCa was associated with increased odds of early and overall mortality and increased blood product requirements. These results support the need for future prospective trials assessing the role of hypocalcemia in trauma.

Geriatric Motorcycle-Related Outcomes: A Pennsylvania Multicenter Study

INTRODUCTION

Geriatric patients (GeP) often experience increased morbidity and mortality following traumatic insult and as a result, require more specialized care due to lower physiologic reserve and underlying medical comorbidities. Motorcycle injuries (MCCI) occur across all age groups; however, no large-scale studies evaluating outcomes of GeP exist for this particular subset of patients. Data thus far are limited to elderly participation in recreational activities such as water and alpine skiing, snowboarding, equestrian, snowmobiles, bicycles, and all-terrain vehicles. We hypothesized that GeP with MCCI will have a higher rate of mortality when compared with their younger counterparts despite increased helmet usage.

METHODS

We performed a multicenter retrospective review of MCCI patients at three Pennsylvania level I trauma centers from January 2016 to December 2020. Data were extracted from each institution's electronic medical records and trauma registry. GeP were defined as patients aged more than or equal to 65 y. The primary outcome was mortality. Secondary outcomes included ventilator days; hospital, intensive care unit, and intermediate unit length of stays; complications; and helmet use. 3:1 nongeriatric patients (NGeP) to GeP propensity score matching (PSM) was based on sex, abbreviated injury scale (AIS), and injury severity score (ISS). P ≤ 0.05 was considered significant.

RESULTS

One thousand five hundred thirty eight patients were included (GeP: 7% [n = 113]; NGP: 93% [n = 1425]). Prior to PSM, GeP had higher median Charlson Comorbidity Index (GeP: 3.0 versus NGeP: 0.0; P ≤ 0.001) and greater helmet usage (GeP: 73.5% versus NGeP: 54.6%; P = 0.001). There was a statistically significant difference between age cohorts in terms of ISS (GeP: 10.0 versus NGeP: 6.0, P = 0.43). There was no significant difference for any AIS body region. Mortality rates were similar between groups (GeP: 1.7% versus NGeP: 2.6%; P = 0.99). After PSM matching for sex, AIS, and ISS, GeP had significantly more comorbidities than NGeP (P ≤ 0.05). There was no difference in trauma bay interventions or complications between cohorts. Mortality rates were similar (GeP: 1.8% versus NGeP: 3.2%; P = 0.417). Differences in ventilator days as well as intensive care unit length of stay, intermediate unit length of stay, and hospital length of stay were negligible. Helmet usage between groups were similar (GeP: 64.5% versus NGeP: 66.8%; P = 0.649).

CONCLUSIONS

After matching for sex, ISS, and AIS, age more than 65 y was not associated with increased mortality following MCCI. There was also no significant difference in helmet use between groups. Further studies are needed to investigate the effects of other potential risk factors in the aging patient, such as frailty and anticoagulation use, before any recommendations regarding management of motorcycle-related injuries in GeP can be made.

Novel method for determining when a field-collected donor unit is sufficiently full

BACKGROUND

Whole blood (WB) collections can occur downrange for immediate administration. An important aspect of these collections is determining when the unit is sufficiently full. This project tested a novel method for determining when a field collection is complete.

METHODS

The amount of empty space at the top of WB units, destined to become LTOWB or separated into components, that were collected at blood centers or hospitals was measured by holding a WB unit off the ground and placing the top of a piece of string where the donor tubing entered the bag. The string was marked where it intersected the top of the column of blood in the bag and measured from the top. The WB units were also weighed.

RESULTS

A total of 15 different bags, two of which were measured in two different filling volumes, from 15 hospitals or blood centers were measured and weighed. The most commonly used blood bag, Terumo Imuflex SP, had a median string length of 9 mm (range: 2-24 mm) and weighed a median of 565.1 g (range: 524.8-636.7 g).

CONCLUSION

Pieces of string can be precut to the appropriate length depending on the type of bag before a mission where field WB collections might be required and a mark placed on the bag before the collection commences to indicate when the unit is full.

Efficacy and Safety of Whole Blood Transfusion in Non-Trauma Patients

Whole blood (WB) transfusion for trauma patients with severe hemorrhage has demonstrated early successful outcomes compared to conventional component therapy. The objective of this study was to demonstrate WB transfusion in the non-trauma patient. Consecutive adult patients receiving WB transfusion at a single academic institution were reviewed from February 2018 to January 2020. Outcomes measured were mortality and transfusion-related reactions. A total of 237 patients who received WB were identified with 55 (23.2%) non-trauma patients. Eight patients (14.5%) received pre-hospital WB. The most common etiology of non-traumatic hemorrhage was gastrointestinal bleeding (43.6%, n = 24/55). Approximately half of the non-trauma patients (n = 28/55) received component therapy. Transfusion-related events occurred in 3 patients. This study demonstrated that non-trauma patients could receive WB transfusions safely with infrequent transfusion-related events. Future studies should focus on determining if outcomes are improved in non-trauma patients who receive WB transfusions and defining specific transfusion criteria for this population.

The effects of hypocalcemia in severely injured pediatric trauma patients

INTRODUCTION

The role of calcium is ubiquitous in human physiology. Emerging evidence suggests that the lethal triad be revised to include hypocalcemia (hypoCa) and thus be known as the lethal diamond . There are data showing that traumatic injury may result in hypoCa independent from the mechanism of calcium chelation by citrate-based blood preservatives. Minimal literature exists analyzing the role of hypoCa in pediatric trauma patients. We hypothesize that there is an independent association of hypoCa with increased blood product requirements and mortality.

METHODS

A retrospective cohort study of severely injured pediatric trauma patients was conducted. Trauma registry data were collected from January 2016 to August 2021. Ionized calcium (iCa) levels were obtained from arrival blood draws. Subjects were categorized into two groups by a threshold iCa level of 1.00 mmol/L and compared. Shock Index Pediatric Adjusted scores were used to adjust for age-specific differences in vital signs.

RESULTS

A total of 142 patients were compared, of which 46.5% were hypocalcemic (iCa <1.00 mmol/L). Patients were well matched in terms of demographics and injury severity. The hypocalcemic group had lower systolic blood pressure and a higher percentage of Shock Index Pediatric Adjusted-positive patients. Weight-adjusted transfusion volumes were significantly higher in the hypocalcemic group at both the 4-hour and 24-hour time points without a difference in prehospital transfusion requirements. There was no observed difference in early or in-hospital mortality.

CONCLUSION

This study contributes to the body of literature regarding the association between hypoCa and traumatic injury in the pediatric population. Hypocalcemia was associated with increased blood product requirements without a difference in prehospital transfusion requirements, suggesting a possible independent association. Further prospective studies are needed to better understand this relationship.

LEVEL OF EVIDENCE

Therapeutic/Care Management; Level IV.

Transfusion-Related Cost Comparison of Trauma Patients Receiving Whole Blood Versus Component Therapy

INTRODUCTION

With the emergence of whole blood in trauma resuscitation, cost-related comparisons are of significant importance to providers, blood banks, and hospital systems throughout the country. The objective of this study is to determine if there is a transfusion-related cost difference between trauma patients that received low titer O+ whole blood (LTO + WB) and component therapy (CT).

METHODS

Retrospective review of adult and pediatric trauma patients who received either LTO + WB or CT from time of injury to within 4 hours of arrival. Annual mean cost per unit of blood product were obtained from the regional blood bank supplier. Pediatric and adult patients were analyzed separately and were compared on a cost per patient (cost/patient) and cost per patient per milliliter (cost/patient/mL) basis. Subgroup analysis was performed on severely injured adult patients (ISS > 15) and patients that underwent massive transfusion (MT).

RESULTS

Prehospital LTO + WB transfusion began at this institution in January 2018. After the initiation of the whole blood transfusion the mean annual cost decreased 17.3% for all blood products and the average net difference in cost related to component blood products and LTO + WB was over $927,000. In adults, LTO + WB was associated with a significantly lower cost/patient and cost/patient/mL compared to CT at 4-hours, (p < 0.001), at 24 hours (p < 0.001), and overall (p < 0.001). In the severely injured subgroup (ISS > 15), WB was associated with a lower cost/patient and cost/patient/mL at 4-hours (p < 0.001), 24 hours (p < 0.001), and overall (p < 0.001), with no difference in the prehospital setting. Similar findings were true in patients meeting MT criteria, although differences in injury severity may account for this finding.

CONCLUSION

With increased use of LTO + WB for resuscitation, cost comparison is of significant importance to all stakeholders. LTO + WB was associated with reduced cost in severely injured patients. Ongoing analyses may improve resource utilization and benefit overall healthcare cost.Level of Evidence: Therapeutic/Care Management, IV.

Prehospital shock index and systolic blood pressure are highly specific for pediatric massive transfusion

BACKGROUND

While massive transfusion protocols (MTPs) are associated with decreased mortality in adult trauma patients, there is limited research on the impact of MTP on pediatric trauma patients. The purpose of this study was to compare pediatric trauma patients requiring massive transfusion with all other pediatric trauma patients to identify triggers for MTP activation in injured children.

METHODS

Using our level I trauma center's registry, we retrospectively identified all pediatric trauma patients from January 2015 to January 2018. Massive transfusion (MT) was defined as infusion of 40 mL/kg of blood products in the first 24 hours of admission. Patients missing prehospital vital sign data were excluded from the study. We retrospectively collected data including demographics, blood utilization, variable outcome data, prehospital vital signs, prehospital transport times, and Injury Severity Scores. Statistical significance was determined using Mann-Whitney U test and χ2 test. p Values of less than 0.05 were considered significant.

RESULTS

Thirty-nine (1.9%) of the 2,035 pediatric patients met the criteria for MT. All-cause mortality in MT patients was 49% (19 of 39 patients) versus 0.01% (20 of 1996 patients) in non-MT patients. The two groups significantly differed in Injury Severity Score, prehospital vital signs, and outcome data.Both systolic blood pressure (SBP) of <100 mm Hg and shock index (SI) of >1.4 were found to be highly specific for MT with specificities of 86% and 92%, respectively. The combination of SBP of <100 mm Hg and SI of >1.4 had a specificity of 94%. The positive and negative predictive values of SBP of <100 mm Hg and SI of >1.4 in predicting MT were 18% and 98%, respectively. Based on positive likelihood ratios, patients with both SBP of <100 mm Hg and SI of >1.4 were 7.2 times more likely to require MT than patients who did not meet both of these vital sign criteria.

CONCLUSION

Pediatric trauma patients requiring early blood transfusion present with lower blood pressures and higher heart rates, as well as higher SIs and lower pulse pressures. We found that SI and SBP are highly specific tools with promising likelihood ratios that could be used to identify patients requiring early transfusion.

LEVEL OF EVIDENCE

Therapeutic/care management, level V.

Previous Laparotomy Scar Preventing Abdominal Injury from Gunshot Wound

Diagnostic laparoscopy has been used in select patients with penetrating abdominal trauma. Here we present a case report where a midline surgical scar from a previous trauma laparotomy potentially prevented intra-abdominal injury. Furthermore, laparoscopy was used to exclude other intra-abdominal injuries and retrieve the projectile from within a hematoma cavity. This avoided the morbidity of a trauma laparotomy.

A protein interaction map of Drosophila melanogaster

Drosophila melanogaster is a proven model system for many aspects of human biology. Here we present a two-hybrid-based protein-interaction map of the fly proteome. A total of 10,623 predicted transcripts were isolated and screened against standard and normalized complementary DNA libraries to produce a draft map of 7048 proteins and 20,405 interactions. A computational method of rating two-hybrid interaction confidence was developed to refine this draft map to a higher confidence map of 4679 proteins and 4780 interactions. Statistical modeling of the network showed two levels of organization: a short-range organization, presumably corresponding to multiprotein complexes, and a more global organization, presumably corresponding to intercomplex connections. The network recapitulated known pathways, extended pathways, and uncovered previously unknown pathway components. This map serves as a starting point for a systems biology modeling of multicellular organisms, including humans.

Macrophages (histiocytes) in various reactive and inflammatory conditions express different antigenic phenotypes

The purpose of this study was to determine whether human tissue macrophages (M phi s) in various inflammatory/reactive conditions express different immunophenotypes. Using a large panel of monoclonal antibodies to monocyte/M phi-related antigens and a frozen-section immunoperoxidase technique, the following conditions were studied: granulomatous inflammation of unknown etiology, sarcoidosis, cat-scratch fever, toxoplasmosis, Gaucher's disease, and juvenile xanthogranulomas. The results show that there is immunophenotypic variation of the M phi s among the various inflammatory/reactive conditions. For example, the M phi s in cat-scratch fever are nearly unique in the expression of the "early inflammation" antigen identified by antibody 27E10, and the M phi s in juvenile xanthogranulomas, unlike those in most of the other conditions, lacked the antigen detected by antibody 25F9. The M phi s in Gaucher's disease differed from those in the other disorders by the combined absence of CD11b, CD14, G16/1, CD1a, CD25, and CD30. The inflammatory/reactive M phi s also exhibited differences from those in "normal" tissues, namely, a tendency toward acquisition of the antigens identified by antibodies Mac 387 and G16/1 and the more uniform expression of the "activation" antigens CD25, CD30, and CD71. The antigenic variations described here probably reflect differences in antigenic stimuli and M phi function. In addition to the possible biologic implications, this M phi immunophenotypic diversity may have practical diagnostic applications.

Comprehension of affect in context in children with pervasive developmental disorders

Fifteen children with Pervasive Developmental Disorders (PDD) (mean age 12.7 years) were compared to mental age matched normal children on matching a context to its appropriate emotion. PDD children were slightly but significantly impaired on this task relative to a non-social task equated for difficulty. Both matching tasks were highly correlated with cognitive variables; the social matching task alone was correlated with social skill level, and neither task was correlated with ratings of social deviance. Results are discussed in terms of the demands of social cognitive tasks, the magnitude of social cognitive findings, control group selection and individual differences.

Affect comprehension in children with pervasive developmental disorders

Affect comprehension was studied in children with pervasive developmental disorders (PDD) and normal children matched for mental age. Three matching tasks were used: matching objects (a nonsocial control task), matching faces, and matching affects. The three tasks were developed to be of equal difficulty for normal children. Children were also tested for comprehension and expression of affect terms. The PDD children were impaired on affect matching relative to the normal controls. The PDD children were impaired on face and affect matching relative to their own performance on object matching, whereas the normal children were not. Within the PDD sample, object matching was correlated with mental age measures but not with measures of social behavior and play, but face and affect matching were significantly correlated with mental age as well as social behavior and play. Individual PDD children who showed relative deficits on face or affect matching tended to be more socially impaired than PDD children whose face and affect matching was consonant with their mental age. Results are discussed in terms of possible etiologies of the social deficit in PDD children, and the importance of subtypes within this population.

The phenotype of human placental macrophages and its variation with gestational age

The antigenic phenotype of human villous stromal macrophages (M phi s) from first and third trimester placentas was analyzed using a large number of monoclonal antibodies (MAbs) to monocyte (Mo)/M phi-associated cell membrane determinants. The purpose of this study was to investigate M phi phenotypic heterogeneity to create a database for the correlation of M phi phenotype with specific immunologic functions. The results showed that villous stromal mononuclear cells express many cell surface antigens found on Mo and M phi s and that they are morphologically diverse, ranging in appearance from classic Hofbauer cells to spindle-shaped cells with long cytoplasmic processes. Villous stromal M phi s were the numerically dominant cell type in this structure and exhibited some major phenotypic differences from M phi s in other tissues. Comparison of first- and third-trimester placentas revealed variation in antigen expression with increasing gestational age, in particular of class II major histocompatibility complex (MHC) determinants: HLA-DR and HLA-DP antigen density was low on first-trimester villous M phi s and much higher on third-trimester M phi s while HLA-DQ was undetectable in the first trimester but present on cells in third trimester placentas. The CD1 (T6) antigen, found on Langerhans (LH) cells and cortical thymocytes, was detected on villous M phi s by two thirds of the MAbs directed against different epitopes on this determinant. Furthermore, comparison with similar studies of lymphoid tissues showed that villous M phi s and dendritic cells share the expression of a number of other cell surface antigens. Finally, it was shown that M phi s in first- and third-trimester villi exhibit strong reactivity with MAbs (Leu 3a,b) to the CD4 antigen that serves as the receptor for the human immunodeficiency virus (HIV), suggesting that these cells may be a portal of entry or reservoir for this virus in the fetuses of pregnant, HIV+ women.

Soluble and particulate forms of rat catechol-O-methyltransferase distinguished by gel electrophoresis and immune fixation

Catechol-O-methyltransferase (COMT) was visualized in homogenates and subcellular fractions of rat tissues, including liver and brain, by gel electrophoresis, electrophoretic transfer of proteins to nitrocellulose (Western blotting), and immune fixation with antiserum to highly purified soluble rat liver COMT. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of all tissue homogenates examined revealed three major immune-specific proteins with apparent molecular weights 23,000, 26,000, and 66,000 (23K, 26K and 66K). Centrifugation of homogenates at 100,000 X g for 60 min resulted in the enrichment of the 26K species protein in the pellet whereas the 23K and 66K proteins were the predominant forms in the supernatant. The 66K protein appeared in variable amounts depending on the tissue being examined and the length of transfer of protein and is assumed to be an "aggregate" of the smaller form(s). The 26K protein was essentially the only immunoreactive species seen in a purified preparation of rat liver outer mitochondrial membrane. Isoelectric focusing (IEF) under denaturing conditions and two-dimensional gel electrophoresis of brain and liver fractions showed that the 23K protein was resolved into three bands of pI 5.1, 5.2, and 5.3, whereas the 26K protein had a pI of 6.2. Analysis of COMT activity in slices from nondenaturing IEF gels indicated that the pI 5.1-5.3 species are biologically active; the pI 6.2 species could not be detected under these conditions. COMT activity was demonstrated, however, in outer mitochondrial membranes from rat liver, which contain predominantly the 26K, pI 6.2 immunoreactive species. The major form of COMT in all rat tissues examined is "soluble" with an apparent Mr of 23K and a pI of 5.2. The nature of the modifications giving rise to pI 5.1 and 5.3 forms of this enzyme are not clear, nor is the relationship between the 23K and 26K forms. Further studies are needed to elucidate the relationship of immunoreactive forms of COMT to each other, their intracellular location, and their functional significance.

Neonatal glucocorticoid administration: effect on the diurnal rhythm of serum concentrations of corticosterone, progesterone and LH, and the response to pregnant mare serum gonadotrophin in immature female rats

The effects of neonatal cortisol acetate administration on diurnal changes in serum corticosterone, progesterone and LH and on the response to pregnant mare serum gonadotrophin (PMSG) were examined in immature female rats. Neonatal cortisol treatment (250 micrograms/rat) abolished the diurnal rhythm of serum progesterone in rats at 27-29 days of age, and lowered overall the serum progesterone response to PMSG. Neonatal cortisol also reduced the number of animals ovulating on day 28 after PMSG injection 48 h earlier. This dosage of cortisol did not alter the diurnal rhythm of serum corticosterone in these animals. Serum LH concentrations in control rats at 27-29 days of age did not differ between 09.00 and 18.00 h, and prior treatment with cortisol acetate did not significantly influence serum concentrations of this hormone. Our data suggest that ovarian production of progesterone contributes significantly to diurnal fluctuations of this steroid in the circulation of immature rats. Perinatal exposure to cortisol acetate abolishes the diurnal rhythm of serum progesterone and impairs the ovarian response of the immature female rat to PMSG. The mechanism(s) by which cortisol acetate alters these processes remains to be determined.

Catechol-O-methyltransferase activity in cultured human skin fibroblasts from controls and patients with dystonia musculorum deformans

Fibroblasts provide a source of living cells that can be obtained easily from humans and used to evaluate inherited differences in the activities of enzymes important in neurotransmitter and drug metabolism. Here, we describe biochemical characteristics of catechol-O-methyltransferase (COMT, EC 2.1.1.6) activity in homogenates of cultured human skin fibroblasts. Many properties of the enzyme, including apparent affinity for dihydroxybenzoic acid and S-adenosyl methionine, optimal pH and (Mg++), and inhibition by Ca++, are similar to those reported in lysates of human erythrocytes. Culture and assay conditions have been established for optimal and reproducible measurement of COMT activity in individual fibroblast lines. In 16 control lines, COMT activity ranged from 115 to 263 pmol/min/mg protein with a mean of 181 pmol/min/mg protein. Enzyme activity did not vary with the age or sex of the donor. The COMT activities in fibroblasts from eight patients with dystonia musculorum deformans, an inherited movement disorder of unknown etiology, were not significantly different from controls. Monoamine oxidase (MAO, EC 1.4.3.4) type A activity was measured in 12 lines from patients with dystonia, and values did not differ significantly from age- and sex-matched controls. We conclude that inherited variation in activity of these two catabolic enzymes is not sufficient to explain alterations in monoamine metabolism described in this disorder.

Onset of psychotraumatic reactions

This study was planned to examine the onset of the posttraumatic psychiatric reaction. Two hundred two injured persons were examined during two summers (1978 and 1979) at the Salzburg Accident Hospital, Austria. Eighty-six of 110 persons with posttraumatic psychiatric reactions developed their symptoms two weeks to two months after the injury. Ninety-two of the 110 showed irritability as the initial symptom.

Monoamine oxidase and catechol-O-methyltransferase activities in cultured fibroblasts and blood cells from children with autism and the Gilles de la Tourette syndrome

Monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT) activities were measured in cells from children with autism (n = 5) and the Gilles de la Tourette syndrome (n = 5). Monoamine oxidase activities in cultured skin fibroblasts (type A) and platelets (type B) from the same individual were not correlated. COMT activities in fibroblasts and red blood cells showed a negative but not significant correlation (r = -0.42). Fibroblast MAO and COMT activities from patients were similar to values from controls matched for age, race, and sex. Increasing clinical severity of illness in both disorders, however, correlated significantly with higher fibroblast MAE activity. Cultured fibroblasts provide a means of measuring enzyme activities independently of the individual's current physiological and psychological state.

Validity of psychotraumatic reactions

To determine whether posttraumatic reactions occurred in injured individuals not confronted with litigation or compensation (as reckoned in the U.S.), a parallel study was undertaken in a social-democratic country (Austria) between ski- and work-injured groups. Although each group had a significantly different way of regarding the injury, there appeared to be a comparable incidence of posttraumatic psychiatric reaction in each. The absence of compensation (in contrast to disability maintenance) did not inhibit the appearance of the posttraumatic reaction. A discussion of the effects of compensation and litigation pointed out the separate nature of the problems associated with these two aspects of dealing with injury, with those problems being imposed upon, but not causative of, the posttraumatic psychiatric reaction.