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Biomedical subjects

John B Holcomb

Publications and source records attributed to John B Holcomb.

At least 19 recordsLinked to original sources
PubMed2026

Evaluation of Physical and Mental Workload and Transfusion Time in Trauma Resuscitation.

BACKGROUND: Trauma resuscitation is time sensitive and complex. Whole blood (WB) and blood components are standard treatments for trauma related hemorrhage, yet their nursing workload and transfusion time have not been well evaluated. PURPOSE: To assess feasibility of a simulation-based crossover trial and obtain preliminary estimates comparing nursing workload and transfusion completion time between WB and blood component administration. METHODS: A randomized crossover pilot study using in situ simulation was conducted with experienced trauma nurses. Time-motion analysis measured transfusion completion time, and the National Aeronautical and Space Administration Task Load Index assessed workload domains. RESULTS: Strong feasibility was demonstrated across recruitment, retention, adherence, and completion. WB was associated with significantly shorter transfusion time, lower overall workload and mental demand, less effort, and better perceived performance. CONCLUSIONS: These findings support the feasibility and justify a fully powered trial. WB may improve resuscitation efficiency and reduce cognitive burden, with potential implications for patient outcomes and nursing workflow.

Humans↗
PubMed2007

Fresh frozen plasma should be given earlier to patients requiring massive transfusion.

BACKGROUND: Acidosis, hypothermia, and coagulopathy were identified more than 20 years ago as a deadly triad for patients presenting with exsanguinating hemorrhage. This led to fundamental changes in initial management of severely injured patients. Despite major advances, hemorrhage remains a leading cause of early death in trauma patients. Recent studies report most severely injured patients to be coagulopathic at admission, before resuscitation interventions, and that traditional massive transfusion practice grossly underestimates needs. The hypothesis for this study is that our pre-intensive care unit (ICU) massive transfusion (MT) protocol does not adequately correct coagulopathy, and that early uncorrected coagulopathy is predictive of mortality. METHODS: Data maintained in our Trauma Research Database were reviewed. Univariate logistic regression analysis was used to analyze the association of early ICU international normalized ratio (INR) and outcomes, including survival. RESULTS: Ninety-seven of 200 patients admitted during 51 months (ending January 2003) and resuscitated using our standardized ICU shock resuscitation protocol received MT (> or =10 units packed red blood cells [PRBC]) during hospital day 1 (age, 39 +/- 2; ISS, 29 +/- 1; survival, 70%.) All patients required emergency operating room and/or interventional radiology procedures and arrived in the ICU 6.8 +/- 0.3 hours after admission. Coagulopathy, present at hospital admission (pre-ICU INR, 1.8 +/- 0.2), persisted at ICU admission (initial ICU INR, 1.6 +/- 0.1). Pre-ICU resuscitation, 9 +/- 1 L crystalloid fluid, 12 +/- 1 units PRBC, 5 +/- 0.4 units fresh frozen plasma (FFP), was consistent with our MT protocol by which FFP was not given until after 6 units PRBC. ICU resuscitation involved 11 +/- 1 L lactated Ringer's solution (LR) and 10 +/- 1 units PRBC. Mean pH was normal within 8 hours. Mean temperature increased from approximately 35 degrees C to >37 degrees C within 4 hours. In the ICU during resuscitation, patients received 10 +/- 1 units FFP for coagulopathy; the ratio of FFP:PRBC was 1:1. Mean INR decreased to 1.4 +/- 0.03 within 8 hours and remained nearly constant for the remaining 16 hours of ICU resuscitation, indicating moderate coagulopathy. Statistical analysis found severity of coagulopathy (INR) at ICU admission associated with survival outcome (p = 0.02; area under receiver operator curve [ROC] = 0.71.) CONCLUSION: These data indicate acidosis and hypothermia to be well managed. Coagulopathy was not corrected in the ICU despite adherence to pre-ICU MT and ICU protocols, likely because of inadequate pre-ICU intervention. More aggressive pre-ICU intervention to correct coagulopathy may be effective in decreasing PRBC requirement during ICU resuscitation, and, because of the association with increased mortality, could improve outcome. We have revised our pre-ICU MT protocol to emphasize early FFP in a FFP:PRBC ratio of 1:1. We think that treatment of coagulopathy can be improved with the development of standardized protocols, both empiric and data driven.

Adult↗
PubMed2007

The potential utility of fibrin sealant dressing in repair of vascular injury in swine.

BACKGROUND: A previous study in which fibrin sealant dressing (FSD) secured hemostasis in major arterial hemorrhage for 96 hours suggested the applicability of this dressing in damage control operations after severe trauma. The objective of this study was to determine the effective duration of FSD hemostatic function in vivo and to examine its potential utility for definitive repair of a major arterial injury in swine. METHODS: High pressure bleeding in an infrarenal aortotomy was controlled by placing FSD on the wound with 4-minute compression (n = 15). If hemostasis was achieved, the abdominal cavity was closed. Surviving animals were killed at 2, 4, 6, and 8 weeks and aortotomy sites collected for histology. RESULTS: FSD stopped arterial hemorrhage after 4-minute compression in 14 of 15 (93%) pigs. Dressings failed in two pigs at 36 and 53 minutes after treatment. Twelve (80%) animals recovered and resumed normal activities. Of the remaining 12, two developed rebleeding at the aortotomy site on days 8 and 11 and were killed; another was killed because of idiopathic low hematocrit on day 10. Nine pigs survived until scheduled to be killed, maintaining hemostasis with stable hematological values. In the surviving animals, serial computed tomography scans showed formation of a pseudoaneurysm at the aortotomy site, which resolved after 2 to 3 weeks. The initial vascular defect and pseudoaneurysm were filled with fibroblast-myoblast collagen rich tissues covered by endothelium. CONCLUSION: FSD can seal an arterial injury, stop high pressure bleeding, and prevent rebleeding for at least 7 days. The dressing may be most beneficial in damage control operations. If combined with an elective interventional radiologic procedure (e.g. embolization or stenting), it may also offer an alternative to suture repair of vascular injuries in cases where profuse bleeding obstructs visualization.

Analysis of Variance↗
PubMed2006

R-wave amplitude in lead II of an electrocardiograph correlates with central hypovolemia in human beings.

OBJECTIVES: Previous animal and human experiments have suggested that reduction in central blood volume either increases or decreases the amplitude of R waves in various electrocardiograph (ECG) leads depending on underlying pathophysiology. In this investigation, we used graded central hypovolemia in adult volunteer subjects to test the hypothesis that moderate reductions in central blood volume increases R-wave amplitude in lead II of an ECG. METHODS: A four-lead ECG tracing, heart rate (HR), estimated stroke volume (SV), systolic blood pressure, diastolic blood pressure, and mean arterial pressure were measured during baseline supine rest and during progressive reductions of central blood volume to an estimated volume loss of >1,000 mL with application of lower-body negative pressure (LBNP) in 13 healthy human volunteer subjects. RESULTS: Lower-body negative pressure resulted in a significant progressive reduction in central blood volume, as indicated by a maximal decrease of 65% in SV and maximal elevation of 56% in HR from baseline to -60 mm Hg LBNP. R-wave amplitude increased (p < 0.0001) linearly with progressive LBNP. The amalgamated correlation (R2) between average stroke volume and average R-wave amplitude at each LBNP stage was -0.989. CONCLUSIONS: These results support our hypothesis that reduction of central blood volume in human beings is associated with increased R-wave amplitude in lead II of an ECG.

Adult↗
PubMed2006

Impact of Acinetobacter infection on the mortality of burn patients.

BACKGROUND: Acinetobacter calcoaceticus-baumannii complex (Acb) is recognized as an important cause of nosocomial infections. Although Acb can be associated with multidrug resistance, its impact on mortality in burn patients has not been fully elucidated. STUDY DESIGN: In a retrospective cohort study assessing medical records and microbiology laboratory data at a US military tertiary care burn center, we evaluated all patients admitted to the burn center between January 2003 and November 2005. Data collected included age, severity of burn, comorbidities, length of stay, and survival to hospital discharge. In addition, microbiology data were reviewed to determine which patients were infected with Acb during this time frame. These data were then used to compare patients infected with Acb to patients not infected. Multivariate analysis using logistic regression was performed to determine which patient characteristics were associated with increased mortality. RESULTS: There were 802 patients included in the study. Fifty-nine patients met the case definition for infection. An additional 52 patients were found to be colonized with Acb. Patients with Acb infection had more severe burns and comorbidities, and had longer lengths of stay compared with patients without Acb or those with Acb colonization. Mortality in infected patients was higher compared with those without infection (relative risk = 2.86, p = 0.001). On multivariate analysis, infection with Acb was not statistically associated with mortality. CONCLUSIONS: Multidrug-resistant Acb is a common cause of nosocomial infection in the burn patient population. Despite this, it does not independently affect mortality.

Acinetobacter Infections↗
PubMed2006

Burns sustained in combat explosions in Operations Iraqi and Enduring Freedom (OIF/OEF explosion burns).

BACKGROUND: Burns comprise 5% of casualties evacuated from Operations Iraqi and Enduring Freedom (OIF and OEF). Many OIF/OEF burns result from the enemy's detonation of explosives. We reviewed these to evaluate mission impact and provide recommendations for improved combat burn protection. Data were compared to those from the Vietnam War. METHODS: All OIF/OEF patients with significant burns are treated at the U.S. Army Institute of Surgical Research (ISR). A review from April 2003 to April 2005 was undertaken. Records were obtained and demographics, burn severity and pattern, and early outcomes recorded. RESULTS: Two hundred and seventy-four OIF/OEF burn patients were treated, 142 (52%) sustained burns in explosions from hostile action. Age was 26+/-7 years (mean+/-S.D.). Mortality was 4%. The annual rate of combat explosion as a cause for burns increased from 18% to 69%, total body surface area burned increased from 15+/-12 to 21+/-23%, injury severity score rose from 8+/-11 to 17+/-18, and frequency of inhalation injury rose from 5% to 26%. Improvised explosive devices caused 55% of casualties, car bombs 16%, rocket-propelled grenades 15% and 14% other. The hands (80% of patients) and the face (77%) were the most frequently burned body areas. Burns were isolated to the hands in 6% of patients and to the face and hands in 15%. An average of 52+/-30% of the surface area of the hands and 45+/-26% of the face was burned. Mean length of stay was 24+/-25 days (median 14). Though 77% of patients were discharged without global disability, only 36% returned to full military duty. A similar pattern of injury and disposition was seen at the Army burn center in Vietnam (1966-1968), but mortality was higher (7.9%). CONCLUSION: Burns resulting from combat explosions increased in frequency, size and injury severity. Burns were concentrated on areas not protected by clothing or equipment. These injuries created long hospital stays and frequently prevented soldiers from returning to duty. While wound distribution has not changed, combat burn care has improved, and continued emphasis on military protective equipment for the hands and face is warranted.

Adolescent↗
PubMed2006

Comparison of combat and non-combat burns from ongoing U.S. military operations.

BACKGROUND: Military burns result from either combat or non-combat causes. We compared these etiologies from patients involved in ongoing conflicts to evaluate their impact and provide prevention recommendations. METHODS: All military patients with significant burns treated at the United States Army Institute of Surgical Research from April 2003 to May 2005 were reviewed. Injuries were categorized as having resulted from combat or non-combat causes. Demographics, burn severity and pattern, mortality, and early outcomes were compared. RESULTS: There were 273 burn patients seen with 63% injured in combat. A high early rate of non-combat injuries was noted. Feedback on non-combat burn prevention was provided to the combat theater, and the incidence of non-combat burns decreased. Mean age and time from injury to admission did not differ. The majority of combat injuries resulted from explosive device detonation. Waste burning, ammunition handling, and gasoline caused most non-combat injuries. Combat casualties had more associated and inhalation injuries and greater full-thickness burn size; total body surface area burned was equivalent. The hands and the face were the most frequently burned body areas. Mortality was 5% in combat and 2% in non-combat patients. The majority of survivors in both groups returned to military duty. CONCLUSIONS: The disparity in full-thickness burn size and incidence of inhalation and associated injuries resulted from differing mechanisms of injury, with explosions and penetrating trauma more common in combat wounds. Despite the severity of combat burns, mortality was low and outcomes generally good. Non-combat burns are preventable and have decreased in incidence.

Burn Units↗
PubMed2006

Risk factors for hepatic morbidity following nonoperative management: multicenter study.

HYPOTHESIS: Early risk factors for hepatic-related morbidity in patients undergoing initial nonoperative management of complex blunt hepatic injuries can be accurately identified. DESIGN: Multicenter historical cohort. SETTING: Seven urban level I trauma centers. PATIENTS: Patients from January 2000 through May 2003 with complex (grades 3-5) blunt hepatic injuries not requiring laparotomy in the first 24 hours. INTERVENTION: Nonoperative treatment of complex blunt hepatic injuries. MAIN OUTCOME MEASURES: Complications and treatment strategies. RESULTS: Of 699 patients with complex blunt hepatic injuries, 453 (65%) were treated nonoperatively. Overall, 61 patients (13%) developed 87 hepatic complications including bleeding (38), biliary (bile peritonitis, 7; bile leak, 9; biloma, 11; biliary-venous fistula, 1; and bile duct injury, 1), abdominal compartment syndrome (5), and infections (abscess, 7; necrosis, 2; and suspected abdominal sepsis, 6), which required 86 multimodality treatments (angioembolization, 32; endoscopic retrograde cholangiopancreatography and stenting, 9; interventional radiology drainage, 16; paracentesis, 1; laparotomy, 24; and laparoscopy, 4). Hepatic complications developed in 5% (13 of 264) of patients with grade 3 injuries, 22% (36 of 166) of patients with grade 4 injuries, and 52% (12 of 23) of patients with grade 5 injuries. Univariate analysis revealed 24-hour crystalloid, total and first 24-hour packed red blood cells, fresh frozen plasma, platelet, and cryoprecipitate requirements and liver injury grade to be significant but only liver injury grade (grade 4 odds ratio, 4.439; grade 5 odds ratio, 12.001) and 24-hour transfusion requirement (odds ratio, 6.446) predicted complications by multivariable analysis. CONCLUSIONS: Nonoperative management of high-grade liver injuries is associated with significant morbidity and correlates with grade of liver injury. Screening patients with transfusion requirements and high-grade injuries may result in earlier diagnosis and treatment of hepatic-related complications.

Abdominal Injuries↗
PubMed2006

A multidisciplinary clinical pathway decreases rib fracture-associated infectious morbidity and mortality in high-risk trauma patients.

BACKGROUND: We initiated a multidisciplinary clinical pathway targeting patients greater than 45 years of age with more than 4 rib fractures. The purpose of the current study was to evaluate the effect of this pathway on infectious morbidity and mortality. METHODS: This was a prospective cohort study. Data evaluated included patient demographics, injury characteristics, pain management details, lengths of stay, morbidity, and mortality. Univariate and multivariate analyses were performed using a significance level of P < .05. RESULTS: When adjusting for age, injury severity score, and number of rib fractures, the clinical pathway was associated with decreased intensive care unit length of stay by 2.4 days (95% confidence interval [CI] -4.3, -0.52 days, P = .01) hospital length of stay by 3.7 days (95% CI -7.1, -0.42 days, P = .02), pneumonias (odds ratio [OR] 0.12, 95% CI 0.04 to 0.34, P < .001), and mortality (OR 0.37, 95% CI 0.13 to 1.03, P = .06). CONCLUSIONS: Implementation of a rib fracture multidisciplinary clinical pathway decreased mechanical ventilator-dependent days, lengths of stay, infectious morbidity, and mortality.

Aged↗
PubMed2006

Comparison between civilian burns and combat burns from Operation Iraqi Freedom and Operation Enduring Freedom.

OBJECTIVE: To assess outcome differences between locally burned civilians and military personnel burned in a distant combat zone treated in the same facility. SUMMARY BACKGROUND DATA: The United States Army Institute of Surgical Research (USAISR) Burn Center serves as a referral center for civilians and is the sole center for significant burns in military personnel. We made the hypothesis that outcomes for military personnel burned in the current conflict in Iraq and Afghanistan would be poorer because of delays to definitive treatment, other associated injury, and distance of evacuation. METHODS: We reviewed the civilian and military records of patients treated at the USAISR from the outset of hostilities in Iraq in April 2003 to May 2005. Demographics, injury data, mortality, and clinical outcomes were compared. RESULTS: : We cared for 751 patients during this time period, 273 of whom were military (36%). Military injuries occurred in a younger population (41 +/- 19 vs. 26 +/- 7 years for civilian and military respectively, P < 0.0001) with a longer time from injury to burn center arrival (1 +/- 5 days vs. 6 +/- 5, P < 0.0001), a higher Injury Severity Score (ISS 5 +/- 8 vs. 9 +/- 11, P < 0.0001), and a higher incidence of inhalation injury (8% vs. 13%, P = 0.024). Total burn size did not differ. Mortality was 7.1% in the civilian and 3.8% in the military group (P = 0.076). When civilians outside the age range of the military cohort were excluded, civilian mortality was 5.0%, which did not differ from the military group (P = 0.57). Total body surface area (TBSA) burned, age > or =40 years, presence of inhalation injury, and ventilator days were found to be important predictors of mortality by stepwise regression, and were used in a final predictive model with the area under receiver operator characteristic curve of 0.97 for both populations considered together. No significant effect of either group was identified during development. CONCLUSIONS: Mortality does not differ between civilians evacuated locally and military personnel injured in distant austere environments treated at the same center.

Adolescent↗
PubMed2006

Heart rate variability and its association with mortality in prehospital trauma patients.

BACKGROUND: Accurate prehospital triage of trauma patients is difficult, especially in mass casualty situations. Accordingly, the U.S. Military has initiated a program directed toward improving noninvasive prehospital triage algorithms based on available physiologic data. The purpose of this study was to assess heart rate variability and its association with mortality in prehospital trauma patients. METHODS: Trauma patients without significant head injury requiring helicopter transport were identified from a retrospective research database. An equal number, unmatched sample of patients who lived were compared with those who died (n = 15 per group). All patients were transported to a single Level I urban trauma center. The primary independent variable was mortality. Patients with Abbreviated Injury Scale head scores >2 were excluded from the analysis, so that the effects seen were based on hemorrhagic shock. Age, sex, Glasgow Coma Scale score (GCS), blood pressure, pulse pressure, pulse, intubation rate, SpO2, mechanism of injury, transport time, and time of death after admission were recorded. R-waves from the first available 120 seconds of usable data were detected from normal electrocardiograms and heart rate variability was assessed. RESULTS: Patients who died demonstrated a lower GCS (7.9 +/- 1.4 versus 14.4 +/- 0.2; p = 0.0001) and higher intubation rate (53% of patients who died versus 0% patients who lived). Pulse rate, arterial pressure, and SpO2 were not distinguishable statistically between groups (p = 0.08), but pulse pressure was lower in patients who died (39 +/- 3 versus 50 +/- 2 mm Hg; p = 0.01). Compared with patients who lived, those who died had lower normalized low-frequency (LF) power (42 +/- 6 versus 62 +/- 4 LFnu; p = 0.009), higher high-frequency (HF) power (42 +/- 3 versus 32 +/- 3 HFnu; p = 0.04) and higher HF-to-LF ratio (144 +/- 30 versus 62 +/- 11nu; p = 0.01). With absolute HF/LF adjusted for GCS, the intergroup variance accounted for by HF/LF was reduced to 6% (p = 0.16). CONCLUSIONS: Analysis of heart rate variability provides insight into adequacy of autonomic compensation to severe trauma. In our cohort of trauma patients, low pulse pressures coupled with relatively higher parasympathetic than sympathetic modulation characterized and separated patients who died versus patients who survived traumatic injuries when standard physiologic measurements are not different. These data do not suggest advantages of heart rate variability analysis over GCS scores, but suggest future possibilities for remote noninvasive triage of casualties when GCS scores are unattainable.

Abbreviated Injury Scale↗
PubMed2006

Arterial pulse pressure and its association with reduced stroke volume during progressive central hypovolemia.

BACKGROUND: The reduction of stroke volume (SV) during hemorrhage reflects the degree of blood loss, but accurate assessment of SV in bleeding patients in the field currently is not possible. In a previous pilot study, we reported that arterial pulse pressure and estimated sympathetic nerve activity (SNA) in trauma patients who died of hemorrhagic injuries was significantly lower than that observed in patients who did not die. For the current study, we measured mean arterial blood pressure (MAP), pulse pressure (PP), SV, and muscle sympathetic nerve activity (MSNA) in human subjects during progressive lower body negative pressure (LBNP) to test the hypothesis that a reduction in PP tracks the reduction of SV and change in MSNA during graded central hypovolemia in humans. METHODS: After a 12-minute baseline data collection period, 13 men were exposed to LBNP at -15 mm Hg for 12 minutes followed by continuous stepwise increments to -30, -45, and -60 mm Hg for 12 minutes each. RESULTS: Comparing baseline to -60 mm Hg chamber decompression, systolic blood pressure (SBP) decreased (from 129 +/- 3.0 to 111 +/- 6.1 mm Hg; p = 0.005) and diastolic pressure was unchanged (78 +/- 3.0 versus 81 +/- 4.0 mm Hg; p = 0.55). Pulse pressure decreased (from 50 +/- 2.5 to 29 +/- 4.0 mm Hg; p = 0.0001). LBNP caused linear reductions in PP and SV (from 125 +/- 9.2 to 47 +/- 6.4; r2 = 0.99), and increases in MSNA (from 14 +/- 3.5 to 36 +/- 4.6 bursts/min; r2 = 0.96) without a significant change in MAP (r2 = 0.28). PP was inversely correlated with MSNA (r2 = 0.88) and positively correlated with SV (r2 = 0.91). CONCLUSIONS: Reduced PP resulting from progressive central hypovolemia is a marker of reductions in SV and elevations in SNA. Therefore, when SBP is >90 mm Hg, PP may allow for early, noninvasive identification of volume loss because of hemorrhage and more accurate and timely triage.

Adult↗
PubMed2006

Making sense of the preclinical literature on advanced hemostatic products.

A number of new hemostatic products have been developed recently for use in trauma settings of severe uncontrolled bleeding. Currently, the literature on these products is controversial, with efficacy demonstrated under some circumstances but not others. In this review, we analyze the current literature pertaining to four of the most promising products (dry fibrin sealant dressing, Rapid Deployment Hemostat, HemCon chitosan dressing, and QuikClot) that have been suggested for use in combat casualty care applications. In particular, this analysis takes into account the characteristics of the animal models used for efficacy testing of these products, the desired characteristics of hemostatic dressings, and specific safety considerations. Animal models ranged from those featuring low-pressure/low-flow bleeding to those featuring high-pressure/high-flow bleeding. When data are viewed in the context of the specific characteristics of the differing animal models used, seemingly disparate experimental results related to efficacy and safety become quite complementary and lead to recommendations for the use of different products in different injury scenarios. Mission and training requirements will dictate the use of these products by military and civilian prehospital care providers.

Animals↗
PubMed2006

A special report on the chitosan-based hemostatic dressing: experience in current combat operations.

BACKGROUND: Hemorrhage remains a leading cause of death in both civilian and military trauma patients. The HemCon chitosan-based hemostatic dressing is approved by the US Food and Drug Administration (FDA) for hemorrhage control. Animal data have shown the HemCon dressing to reduce hemorrhage and improve survival. The purpose of this article is to report preliminary results of the hemostatic efficacy of the HemCon dressing used in the prehospital setting on combat casualties. METHODS: A request for case information on use of HemCon dressings in Operation Iraqi Freedom and Operation Enduring Freedom was sent to deployed Special Forces combat medics, physicians, and physician assistants. RESULTS: Sixty-eight uses of the HemCon dressing were reported and reviewed by two US Army physicians. Four of the 68 cases were determined duplicative resulting in a total of 64 combat uses. Dressings were utilized externally on the chest, groin, buttock, and abdomen in 25 cases; on extremities in 35 cases; and on neck or facial wounds in 4 cases. In 66% of cases, dressings were utilized following gauze failure and were 100% successful. In 62 (97%) of the cases, the use of the HemCon dressing resulted in cessation of bleeding or improvement in hemostasis. There were two reported dressing failures that occurred with blind application of bandages up into large cavitational injuries. Dressings were reported to be most useful on areas where tourniquets could not be applied to control bleeding. The dressings were reported to be most difficult to use in extremity injuries where they could not be placed easily onto or into the wounds. No complications or adverse events were reported. CONCLUSION: This report on the field use of the HemCon dressing by medics suggests that it is a useful hemostatic dressing for prehospital combat casualties and supports further study to confirm efficacy.

Bandages↗
PubMed2006

Understanding combat casualty care statistics.

Maintaining good hospital records during military conflicts can provide medical personnel and researchers with feedback to rapidly adjust treatment strategies and improve outcomes. But to convert the resulting raw data into meaningful conclusions requires clear terminology and well thought out equations, utilizing consistent numerators and denominators. Our objective was to arrive at terminology and equations that would produce the best insight into the effectiveness of care at different stages of treatment, either pre or post medical treatment facility care. We first clarified three essential terms: 1) the case fatality rate (CFR) as percentage of fatalities among all wounded; 2) killed in action (KIA) as percentage of immediate deaths among all seriously injured (not returning to duty); and 3) died of wounds (DOW) as percentage of deaths following admission to a medical treatment facility among all seriously injured (not returning to duty). These equations were then applied consistently across data from the WWII, Vietnam and the current Global War on Terrorism. Using this clear set of definitions we used the equations to ask two basic questions: What is the overall lethality of the battlefield? How effective is combat casualty care? To answer these questions with current data, the three services have collaboratively created a joint theater trauma registry (JTTR), cataloging all the serious injuries, procedures, and outcomes for the current war. These definitions and equations, consistently applied to the JTTR, will allow meaningful comparisons and help direct future research and appropriate application of personnel.

Afghanistan↗
PubMed2006

Does bicarbonate correct coagulation function impaired by acidosis in swine?

BACKGROUND: Coagulopathy is an important contributor to morbidity and mortality in trauma patients. Acidosis contributes to coagulopathy. Acidosis can be neutralized with intravascular bicarbonate, but it is unclear if the coagulation defect is rapidly reversed. The effects of acidosis and bicarbonate neutralization on coagulation function were investigated in vivo. METHODS: Acidosis was induced in 12 pigs by infusing 0.2 mol/L HCl to pH 7.1. Pigs were then infused with either LR to maintain a pH of 7.1 (A-LR, n = 6) or 0.3 mol/L bicarbonate to a pH of 7.4 (A-Bi, n = 6). Blood samples were taken at baseline, 15 minutes after acidosis induction, and 15 minutes after bicarbonate neutralization. Coagulation function was assessed by prothrombin time (PT), partial thromboplastin time (PTT), thrombin generation, initial clot formation time (R), clotting rapidity (alpha), and clot strength (MA). RESULTS: Compared with baseline values, acidosis reduced fibrinogen concentration to 66% +/- 2% in A-LR and to 71% +/- 3% in A-Bi, and decreased platelet counts to 49% +/- 4% in A-LR and to 53% +/- 4% in A-Bi. Thrombin generation decreased to 60% +/- 4% in A-LR and to 53% +/- 7% in A-Bi. Acidosis prolonged PT and PTT about 20% and decreased alpha and MA. After pH neutralization, fibrinogen and platelet levels remained depleted and no reversal of acidosis-induced changes in thrombin generation, PT, PTT, alpha, and MA were observed. CONCLUSION: Acidosis impaired coagulation by depleting fibrinogen and platelets and by inhibiting clotting kinetics. The deficit associated with acidosis was not reversed with bicarbonate pH neutralization.

Acidosis↗