Biomedical subjects

Peter Rhee

Publications and source records attributed to Peter Rhee.

At least 37 records · Page 2Linked to original sources

PubMed2006

The effect of a protocol of aggressive donor management: Implications for the national organ donor shortage.

BACKGROUND: The disparity between the number of people awaiting organ transplantation and the number of organs available has become a public health crisis. As many as 25% of potential donors are lost as a result of cardiovascular collapse (CVC) before organ harvest. A policy of aggressive donor management (ADM) may decrease the number of cadaveric donors lost as a result of CVC. METHODS: Retrospective analysis of potential brain-dead donors evaluated from January 1995 to December 2003 at nine American College of Surgeons-verified Level I trauma centers covered by a regional organ procurement agency. One center (Los Angeles County + University of Southern California Medical Center [LAC]) had an ADM protocol in place instituted January 1999; the remaining eight centers with no ADM protocol were grouped as Center A. The incidence of CVC and organ donation demographics were compared between centers and within LAC before (LAC-Pre) and after (LAC-Post) adoption of ADM. ADM consists of early identification of potential organ donors, a dedicated team that provides medical management, and aggressive fluid resuscitation as well as hormone replacement therapy with solumedrol and thyroxin. RESULTS: The incidence of CVC was significantly higher in LAC-Pre (odds ratio [OR] 15.0, p < 0.001) and Center A (OR 5.8, p < 0.001) compared with LAC-Post. The number of organs harvested per potential donor for LAC-Post (2.4) was significantly higher than LAC-Pre (2.0, p = 0.02) and Center A (2.1, p < 0.01). CONCLUSION: An aggressive donor management protocol decreases the number of donors lost as a result of cardiovascular collapse and increases the number of harvested organs per potential donor.

Adult↗

PubMed2006

Admission physiology criteria after injury on the battlefield predict medical resource utilization and patient mortality.

BACKGROUND: Medical resources and resource allocation including operating room and blood utilization are of prime importance in the modern combat environment. We hypothesized that easily measurable admission physiologic criteria and injury site as well as injury severity calculated after diagnostic evaluation or surgical intervention, would be strongly correlated with resource utilization and in theater mortality outcomes. METHODS: We retrospectively reviewed the Joint Theater Trauma Registry for all battlefield casualties presenting to surgical component facilities during Operation Iraqi Freedom from January to July 2004. Data were collected from the composite population of 1,127 battlefield casualty patients with respect to demographics, mechanism, presentation physiology (blood pressure, heart rate, temperature), base deficit, admission hematocrit, Glasgow Coma Score (GCS), Injury Severity Score (ISS), operating room utilization, blood transfusion, and mortality. Univariate and multivariate analyses were conducted to determine the degree to which admission physiology and injury severity correlated with blood utilization, necessity for operation, and acute mortality. RESULTS: Univariate analysis demonstrated a significant (p < 0.05) association between hypothermia (T < 34 degrees C) and the subsequent requirement for operation and mortality. In addition, the outcome variable total blood product utilization was significantly correlated with base deficit (r = 0.61), admission hematocrit (r = 0.51), temperature (r = 0.47), and ISS (r = 0.54). Using multiple logistic regression techniques, blood pressure, GCS, and ISS together demonstrated a significant association (p < 0.05) with mortality (area under ROC curve = 95%). Multiple linear regression established that blood pressure, heart rate, temperature, hematocrit, and ISS had a collective significant effect (p < 0.05) on total blood product utilization explaining 67% of the variance in this outcome variable. CONCLUSION: Admission physiology and injury characteristics demonstrate a strong capacity to predict resource utilization in the contemporary battlefield environment. In the future, such predictive yield could potentially have significant implications for triage and medical logistics in the resource constrained environment of war and potentially in mass casualty and disaster incidents in the civilian trauma setting which will likely have mechanistic similarity with war related injury.

Blood Pressure↗

PubMed2006

Testing of modified zeolite hemostatic dressings in a large animal model of lethal groin injury.

BACKGROUND: We have previously identified a granular zeolite hemostat (ZH) as an effective agent for control of severe bleeding, and it is currently being used by the US troops in the battlefield. ZH causes an exothermic reaction on application, which theoretically can be decreased by altering its chemical composition or changing its physical properties. However, the effect of these alterations on the hemostatic efficacy is unknown. We tested modified zeolites and a chitosan based dressing against controls in a swine model of battlefield injury. METHODS: A complex groin injury was created in 60 swine (40-55 kg). This included semi-transection of the proximal thigh (level of inguinal ligament), and complete division of the femoral artery and vein. After 3 minutes, the animals were assigned to (1) no dressing (ND), (2) standard dressing (SD), (3-5) SD + chemically modified ZHs, where calcium was substituted with sodium (Na), barium (Ba), or silver (Ag), respectively, (6) SD + physically modified ZH, where "beads" were packaged in a fabric bag, (7) SD + chitosan based dressing (CD). Resuscitation was started 15 minutes after application of dressing (500 mL of 6% hetastarch over 30 minutes). Survival for 180 minutes was the primary endpoint for this study. In addition, blood loss, wound temperatures, and histologic tissue damage were recorded. RESULTS: Mortality in the group that was treated with the application of bagged ZH was 10% versus 100% in the no dressing group and 50% in the SD group (p < 0.05 vs. ND and SD groups). The Na ZH group had a mortality rate of 43%, whereas application of Ba and Ag substituted zeolites, and CD were associated with a mortality rate of 25%. Ionic substitution of zeolite decreased the in vivo temperature peak by 5 to 10 degrees C. No histologic evidence of tissue necrosis was noted in this experiment. CONCLUSIONS: The use of zeolite hemostat can control hemorrhage and dramatically reduce mortality from a lethal groin wound. Modifications of zeolite hemostat can decrease the exothermic reaction and attenuate tissue damage.

Animals↗

PubMed2006

Development and testing of portable pump for the induction of profound hypothermia in a Swine model of lethal vascular injuries.

UNLABELLED: Rapid induction of a profound hypothermic state (suspended animation) can maintain viability of key organs during repair of lethal injuries. Conventional cardiopulmonary bypass equipment (roller pump) used to induce and reverse hypothermia is expensive, bulky, requires standard electricity, and is not transportable. Development of a small, portable, battery operated, disposable, pump can logistically facilitate induction and maintenance of hypothermia. In this experiment, a portable prototype pump was tested and its performance was compared with the regular roller pump in a swine model of lethal vascular injuries. METHODS: Uncontrolled hemorrhage was induced in 16 swine (80-120 lbs) by creating an iliac artery and vein injury (nonlethal). After 30 minutes of pulseless shock, the descending thoracic aorta was lacerated (lethal injury). Through a left thoracotomy approach, a catheter was placed in the aorta and cold organ preservation solution was infused to rapidly (2 degrees C/min) induce hypothermia (10 degrees C) for 60 minutes. The performance of the prototype pump was initially tested in a nonsurvival experiment (four animals). Then, 12 animals were cooled either with (n = 6/group) (1) conventional roller pump or (2) small prototype pump. The injuries were repaired during hypothermic arrest and the animals were re-warmed (0.5 degrees C/min). Whole blood was infused during resuscitation on cardiopulmonary bypass. Surviving animals were closely monitored for 3 weeks for postoperative complications, neurologic deficits, and organ dysfunction. RESULTS: The flow rates and the time needed to induce and reverse profound hypothermia were no different between the prototype and the conventional roller pumps. Three-week survival rates were 83% in both groups. Only a transient increase in liver enzymes, and markers of cellular injury (creatine kinase, lactate dehydrogenase) was noted (no meaningful difference between groups), with no long-term organ dysfunction. CONCLUSIONS: In this large animal model of lethal vascular injuries, a portable, battery operated, disposable, rotary pump performed as well as the conventional roller pump. The logistical advantages of this system make it an attractive choice for inducing hypothermia in emergency departments and austere settings, and for maintaining hypothermia during transport.

Animals↗

PubMed2006

Emergency department hypotension is not an independent risk factor for post-traumatic acute renal dysfunction.

BACKGROUND: Hypotension has been considered to be associated with renal dysfunction. The purpose of this study was to characterize the association of Emergency Department Hypotension (EDHypo) with post-traumatic renal insufficiency (RI) and renal failure (RF). METHODS: A Level I center Intensive Care Unit database was analyzed. We reviewed all adult trauma patients surviving for more than 24 hours. EDHypo was defined as admission systolic blood pressure of less than 90 mm Hg, RI was defined as a peak serum creatine of > or = 2.0 mg/dL, RF was defined as requiring dialysis. RESULTS: There were 2,574 admissions studied and RI occurred in 8.3% (213) of these patients whereas RF occurred in 1.1% (28). The mortality rate with RI was 41.0% (89) and 50.0% (14) with RF. There was no significant change in the incidence of RI, RF, or RI associated mortality during the study period. EDHypo was present in 7.9% (203) of patients and the incidence of RI was significantly higher than that of non-EDHypo patients (12.2% vs. 7.9%, p = 0.028). The incidence of RF was not different (1.0% vs. 1.1%). EDHypo was not independently associated with RI or RF but Injury Severity Score > 16, renal injury, age > 55, Body Mass Index > 30, male gender, and Intensive Care Unit (ICU) admission creatine kinase > or = 5,000 U/L had an independent association with RI. No risk factor in patients with RI could reliably predict RF. CONCLUSIONS: EDhypo is not independently associated with post-traumatic RI or RF but severity of injury, renal injury, age, Body Mass Index, male gender, and elevated creatinine kinase are independently associated with RI. In critically ill trauma patients the incidence of RI and RF and the associated mortality rate has not changed significantly during a 6-year period despite, presumably, better understanding of resuscitative strategies.

Adult↗

PubMed2006

Complications of brain death: frequency and impact on organ retrieval.

Brain death is associated with complex hemodynamic, endocrine, and metabolic dysfunction that can lead to major complications with the potential donor. Untreated, this can progress to cardiovascular collapse with loss of valuable organs for transplantation. We hypothesized that brain death-related complications would have no effect on the number of organs donated if an aggressive donor management protocol was in place. We identified all successful organ donations between January 2000 and December 2003 and evaluated them for brain death-associated complications (defined as vasopressor requirement, coagulopathy, diabetes insipidus, cardiac ischemia, lactic acidosis, renal failure, and acute respiratory distress syndrome) and donated organs per donor. Sixty-nine organ donors were identified. Complications identified were as follows: intravenous vasopressor requirement in 97.1 per cent, coagulopathy in 55.1 per cent, thrombocytopenia in 53.6 per cent, diabetes insipidus in 46.4 per cent, cardiac ischemia in 30.4 per cent, lactic acidosis in 24.6 per cent, renal failure in 20.3 per cent, and acute respiratory distress syndrome in 13 per cent. There was no significant effect of complications on the average number of organs harvested, with the exception of an increase in organs harvested in the presence of diabetes insipidus. With the implementation of an aggressive organ donor management protocol, these complications can be effectively managed with no impact on the number of organs harvested for transplant.

Adult↗

PubMed2006

Humanitarian aid mission in east timor: experiences of U.S. Naval medical services.

The U.S. military was actively involved in humanitarian aid throughout the world for much of the 20th century and is likely to continue in this role well into the 21st century. During the recent Western Pacific Deployment, we were called on to provide assistance to the local population in East Timor in what is called a humanitarian assistance operation. This article explores this increasingly important role of military medicine and is written in hopes of providing insight to future teams planning altruistic deployments to underserved countries. The spectrum of topics covered includes personnel, equipment, supplies, resources, and the type of medical needs that were met. This information may also be useful as a reference for military and nonmilitary health care workers who find themselves assisting people and nations in need.

Altruism↗

PubMed2006

Noninvasive hemodynamic monitoring for combat casualties.

The aims of this study were to develop and to test a noninvasive hemodynamic monitoring system that could be applied to combat casualties to supplement conventional vital signs, to use an advanced information system to predict outcomes, and to evaluate the relative effectiveness of various therapies with instant feedback information during acute emergency conditions. In a university-run inner city public hospital, we evaluated 1,000 consecutively monitored trauma patients in the initial resuscitation period, beginning shortly after admission to the emergency department. In addition to conventional vital signs, we used noninvasive monitoring devices (cardiac index by bioimpedance with blood pressure and heart rate to measure cardiac function, arterial hemoglobin oxygen saturation by pulse oximetry to reflect changes in pulmonary function, and tissue oxygenation by transcutaneous oxygen tension indexed to fractional inspired oxygen concentration and carbon dioxide tension to evaluate tissue perfusion). The cardiac index, mean arterial pressure, pulse oximetry (arterial hemoglobin oxygen saturation), and transcutaneous oxygen tension/fractional inspired oxygen concentration were significantly higher in survivors, whereas the heart rate and carbon dioxide tension were higher in nonsurvivors. The calculated survival probability was a useful outcome predictor that also served as a measure of severity of illness. The rate of misclassification of survival probability was 13.5% in the series as a whole but only 6% for patients without severe head injuries and brain death. Application of noninvasive hemodynamic monitoring to acute emergency trauma patients in the emergency department is feasible, safe, and inexpensive and provides accurate hemodynamic patterns in continuous, on-line, real-time, graphical displays of the status of cardiac, pulmonary, and tissue perfusion functions. Combined with an information system, this approach provided an early outcome predictor and evaluated, with an objective individualized method, the relative efficacy of alternative therapies for specific patients.

Adult↗

PubMed2006

Splenectomy for trauma increases the rate of early postoperative infections.

Little is known what effect splenectomy for trauma has on early postoperative infectious complications. Our aim was to determine if splenectomy increases early postoperative infections in trauma patients undergoing laparotomy. We reviewed all trauma patients undergoing splenectomy from June 2002 through December 2004. Each splenectomy patient was matched to a unique trauma patient who underwent laparotomy without splenectomy based on age, gender, mechanism of injury, injury severity score, and presence of colon or other hollow visceral injury. Outcomes included infectious complications including pneumonia, urinary tract infection, bacteremia, and intra-abdominal abscess, as well as mortality. There were 98 splenectomy patients and 98 controls. The splenectomy patients had more overall infectious complications (45% vs 30%, P = 0.04) trended toward more urinary tract infections (12% vs 5%, P = 0.12), and more often had pneumonia (30% vs 14%, P = 0.02). Additionally, more splenectomy patients developed multiple infections (20% vs 7%, P = 0.01). There was no difference in mortality (11% vs 8%, P = 0.63). Splenectomy is associated with an increase in infectious complications after laparotomy for trauma. More specifically, splenectomy patients more often develop pneumonia and multiple infections. This increase in infections is not associated with increased mortality.

Abdominal Abscess↗

PubMed2005

Relationship between American College of Surgeons trauma center designation and mortality in patients with severe trauma (injury severity score > 15).

BACKGROUND: We studied the association of the American College of Surgeons (ACS) trauma center designation and mortality in adult patients with severe trauma (Injury Severity Score > 15). ACS designation of trauma centers into different levels requires substantial financial and human resources commitments. There is very little work published on the association of ACS trauma center designation and outcomes in severe trauma. STUDY DESIGN: National Trauma Data Bank study including all adult trauma admissions (older than 14 years of age) with Injury Severity Score (ISS) > 15. The relationship between ACS level of trauma designation and survival outcomes was evaluated after adjusting for age, mechanism of injury, ISS, hypotension on admission, severe liver trauma, aortic, vena cava, iliac vascular, and penetrating cardiac injuries. RESULTS: A total of 130,154 patients from 256 trauma centers met the inclusion criteria. Adjusted mortality in ACS-designated Level II centers and undesignated centers was notably higher than in Level I centers (adjusted odds ratio, 1.14; 95% CI, 1.09-120; p < 0.0001 and adjusted odds ratio, 1.09; CI, 1.05-1.13; p < 0.0001, respectively). CONCLUSIONS: Severely injured patients with ISS > 15 treated in ACS Level I trauma centers have considerably better survival outcomes than those treated in ACS Level II centers.

Adolescent↗

PubMed2005

Hepatic apoptosis after hemorrhagic shock in rats can be reduced through modifications of conventional Ringer's solution.

BACKGROUND: Resuscitation with racemic lactated Ringer's solution induces cellular apoptosis. This study was conducted to determine if the elimination of D-lactate isomer would attenuate apoptosis in the liver, and to investigate the possible mechanisms. STUDY DESIGN: Sprague Dawley rats (n=30, 5 per group) were subjected to modified volume-controlled hemorrhage and randomized to the following groups: no hemorrhage (sham); no resuscitation (NR); resuscitation with racemic lactated Ringer's (DL-LR); L-isomer LR (L-LR); ketone (beta-hydroxybuturate) Ringer's (KR); or pyruvate Ringer's (PR). Animals were sacrificed 2 hours later and expressions of proapoptotic proteins (BAD), antiapoptotic (bcl-2) proteins, and poly-ADP ribose polymerase (PARP) cleavage in liver were analyzed by Western blotting. Contribution of the phosphatidylinositol 3-kinase/serine/threonine kinase (PI3k/Akt) pathway was assessed by measuring total and phosphorylated PI3K, Akt, BAD, and endothelial nitric oxide synthase (eNOS) proteins. The terminal deoxynucleotidyl transferase mediated dUTP nick end labeling (TUNEL) assay was used to detect the apoptotic cells. Liver ATP levels were measured using a luciferase reaction assay. RESULTS: Hemorrhage significantly decreased the hepatic ATP level and resuscitation improved it, but it returned to normal only in the L-isomer lactated Ringer's and ketone Ringer's groups. Expression of proapoptotic proteins was significantly lower in the pyruvate Ringer's and ketone Ringer's groups; L-isomer lactated Ringer's and pyruvate Ringer's resuscitation significantly increased bcl-2 expression. Poly-ADP ribose polymerase fragmentation and total number of apoptotic cells were significantly increased in the racemic lactated Ringer's group. There was no significant induction of Akt activity or changes in phosphorylated BAD, Akt, or eNOS levels. CONCLUSIONS: Resuscitation with racemic lactated Ringer's induces hepatic apoptosis, which is decreased if the D-isomer of lactate is eliminated. Apoptosis is reduced even more when lactate is substituted with beta-hydroxybutyrate or pyruvate. The beneficial effects are not through improvements in the energy status or activation of the PI3K/Akt pathway.

Adenosine Diphosphate↗

PubMed2005

Profound hypothermia protects neurons and astrocytes, and preserves cognitive functions in a Swine model of lethal hemorrhage.

BACKGROUND: Lethal injuries can be repaired under asanguineous hypothermic arrest (suspended animation) with excellent survival. This experiment was designed to test the impact of this strategy on neuronal and astroglial damage in a swine model of lethal hemorrhage. Furthermore, our goal was to correlate the histological changes in the brain with neurological outcome, and the levels of circulating brain specific markers. MATERIALS AND METHODS: Uncontrolled hemorrhage was induced in 32 female swine (80-120 lbs) by creating an iliac artery and vein injury, followed 30 min later by laceration of the thoracic aorta. Through a thoracotomy approach, organ preservation fluid was infused into the aorta using a roller pump. Experimental groups included normothermic controls (no cooling, NC), and groups where hypothermia was induced at three different rates: 0.5 degrees C/min (slow, SC), 1 degrees C/min (medium, MC), or 2 degrees C/min (fast, FC). Profound hypothermia (core temperature of 10 degrees C) was maintained for 60 min for repair of vascular injuries, after which the animals were re-warmed (0.5 degrees C/min) and resuscitated on cardiopulmonary bypass (CPB). Circulating levels of neuron specific enolase (NSE) and S-100beta were serially measured as markers of damage to neurons and astrocytes, respectively. Light microscopy and quantitative immunohistochemical techniques were used to evaluate hippocampal CA1 area and caudate putamen for neuronal injury and astrogliosis (astrocyte hyperplasia/hypertrophy). Surviving animals were observed for 6 weeks and neurological status was documented on an objective scale, and cognitive functions were evaluated using a technique based upon the concept of operant conditioning. RESULTS: Normothermic arrest resulted in clinical brain death in all of the animals. None of the surviving hypothermic animals displayed any neurological deficits or cognitive impairment. On histological examination, normothermic animals were found to have ischemic changes in the neurons and astrocytes (hypertrophy). In contrast, all of the hypothermic animals had histologically normal brains. The circulating levels of brain specific proteins did not correlate with the degree of brain damage. The changes in NSE levels were not statistically significant, whereas S-100beta increased in the circulation after CPB, largely independent of the temperature modulation. CONCLUSIONS: Profound hypothermia can preserve viability of neurons and astrocytes during prolonged periods of cerebral hypoxia. This approach is associated with excellent cognitive and neurological outcome following severe shock. Circulating markers of central nervous system injury did not correlate with the actual degree of brain damage in this model.

Animals↗

PubMed2005

Induction of profound hypothermia modulates the immune/inflammatory response in a swine model of lethal hemorrhage.

UNLABELLED: Profound hypothermic arrest ("suspended animation") is a new strategy to improve outcome following uncontrolled lethal hemorrhage (ULH). However, the impact of this approach on the immune/inflammatory response is unknown. This experiment was conducted to test the influence of profound hypothermia on markers of immune/inflammatory system. METHODS: ULH was induced in 32 female swine (80-120 lb) by creating an iliac artery and vein injury, followed 30 min later by laceration of the descending thoracic aorta. Through a left thoracotomy approach, total body hypothermic hyperkalemic metabolic arrest was induced by infusing organ preservation fluids into the aorta using a cardiopulmonary bypass machine (CPB). Experimental groups were (1) normothermic controls (no cooling, NC), or hypothermia induced at the following rates: (2) 0.5 degrees C/min (slow, SC), (3) 1 degrees C/min (medium, MC) and (4) 2 degrees C/min (fast, FC). Vascular injuries were repaired during 60 min of profound (10 degrees C) hypothermic arrest. Hyperkalemia was reversed by hypokalemic fluid exchange, and blood was infused for resuscitation during re-warming (0.5 degrees C/min). The surviving animals were monitored for 6 weeks. Levels of IL-1, TNFalpha, IL-6, IL-10, TGF-1 beta and heat shock protein (HSP-70) were measured by ELISA in serum samples collected serially during the experiment and post-operatively. RESULTS: Some of the immune markers were influenced by the use of CPB, independent of hypothermia (decrease in TGF-1 beta and increase in IL-1 beta). Hypothermia caused a significant decrease in IL-6, and an increase in HSP-70 expression compared to normothermic controls, independent of the cooling rate. An increase in IL-10 levels was noted which was influenced by the rate of cooling (p<0.05, MC versus NC). CONCLUSIONS: Profound hypothermia modulates the post-shock immune/inflammatory system by attenuating the pro-inflammatory IL-6, increasing anti-inflammatory IL-10 and augmenting the protective heat shock responses.

Animals↗

PubMed2005

Initial experience of US Marine Corps forward resuscitative surgical system during Operation Iraqi Freedom.

HYPOTHESIS: Modern US Marine Corps (USMC) combat tactics are dynamic and nonlinear. While effective strategically, this can prolong the time it takes to transport the wounded to surgical capability, potentially worsening outcomes. To offset this, the USMC developed the Forward Resuscitative Surgical System (FRSS). By operating in close proximity to active combat units, these small, rapidly mobile trauma surgical teams can decrease the interval between wounding and arrival at surgical intervention with resultant improvement in outcomes. DESIGN: Case series. SETTING: Echelon 2 surgical units during the invasion phase of Operation Iraqi Freedom. PATIENTS: Ninety combat casualties, consisting of 30 USMC and 60 Iraqi patients, were treated in the FRSS between March 21 and April 22, 2003. INTERVENTIONS: Tactical surgical intervention consisting of selectively applied damage control or definitive trauma surgical procedures. MAIN OUTCOME MEASURES: Time to surgical intervention and outcome following treatment in the FRSS. RESULTS: Ninety combat casualties with 170 injuries required 149 procedures by 6 FRSS teams. The USMC patients were received within a median of 1 hour of wounding with the critically injured being received within a median of 30 minutes. Fifty-three USMC personnel were killed in action and 3 died of wounds for a killed in action rate of 13.5% and a died of wounds rate of 0.8% during the invasion phase of Operation Iraqi Freedom. All Marines treated in the FRSS survived. CONCLUSION: The use of the FRSS in close proximity to the point of engagement during the initial, dynamic combat phase of Operation Iraqi Freedom prevented delays in surgical intervention of USMC combat casualties with resultant beneficial effects on patient outcomes.

Blast Injuries↗

PubMed2005

Hemodynamically "stable" patients with peritonitis after penetrating abdominal trauma: identifying those who are bleeding.

HYPOTHESIS: Despite initial presentation, hemodynamically stable patients with penetrating abdominal trauma may have significant ongoing hemorrhage and major intra-abdominal injuries requiring emergent surgical intervention. DESIGN: Cohort analytic study. SETTING: Academic, level I trauma center. PATIENTS: One hundred thirty-nine consecutive hemodynamically stable patients with penetrating abdominal trauma in whom peritonitis was the sole indication for laparotomy. MAIN OUTCOME MEASURES: The primary outcome was the amount of blood initially found at laparotomy. Secondary outcomes included additional intraoperative blood loss, intraoperative hypotension, transfusion, fluid, and vasopressor requirement; need for admission to the intensive care unit and mechanical ventilation; complications; survivor length of stay in the hospital and intensive care unit; and mortality. RESULTS: The admission systolic blood pressure (mean +/- SD, 131 +/- 22 mm Hg) and heart rate (mean +/- SD, 91 +/- 22 beats/min) were normal. Median time from peritonitis to incision was 40 minutes. Ninety-seven percent of patients had intra-abdominal injury, including 81%, hollow visceral; 36%, solid organ; and 11%, vascular injury. Though most patients had less than 750 mL(3) of blood found initially at laparotomy, there were 11% with 750 to 1500 mL(3) and 7% with 1500 mL(3) or more. Intraoperative hypotension (25%) and blood transfusion (39%) were common. Postoperatively, 40% of patients required intensive care (78% of them requiring mechanical ventilation) and 19% required additional transfusion within 24 hours. Complications occurred in 25% of patients, with intra-abdominal abscess (12%) and wound infection (7%) being the most common. Three patients died, 2 of exsanguination and 1 of multisystem organ failure. CONCLUSIONS: Following penetrating abdominal trauma, peritonitis should be a trigger for emergent operation regardless of vital signs, because hemodynamic "stability" does not reliably exclude significant hemorrhage. Vascular injury, subsequent hypotension, blood transfusion, and complicated postoperative course are common in this population.

Abdominal Injuries↗

PubMed2005

Combat casualty care research: from bench to the battlefield.

Hemorrhagic shock is the leading cause of death in civilian and combat trauma. Effective hemorrhage control and better resuscitation strategies have the potential of saving lives. The Trauma Readiness and Research Institute for Surgery (TRRI-Surg) was established to address the core mission of the Uniformed Services University, "Learning to Care for Those in Harm's Way," by conducting research to improve the outcome of combat casualties. This article highlights the salient achievements of this research effort in the areas of hemorrhage control, resuscitation, design and testing of devices, and some novel concepts such as the use of profound hypothermia. The impact of these basic science research findings on changes in military medical care and outcome of injured soldiers is also described.

Humans↗

PubMed2005

Trauma deaths in a mature urban trauma system: is "trimodal" distribution a valid concept?

BACKGROUND: Trimodal distribution of trauma deaths, described more than 20 years ago, is still widely taught in the design of trauma systems. The purpose of this study was to examine the applicability of this trimodal distribution in a modern trauma system. STUDY DESIGN: A study of trauma registry and emergency medical services records of trauma deaths in the County of Los Angeles was conducted over a 3-year period. The times from injury to death were analyzed according to mechanism of injury and body area (head, chest, abdomen, extremities) with severe trauma (abbreviated injury score [AIS] >/= 4). RESULTS: During the study period there were 4,151 trauma deaths. Penetrating trauma accounted for 50.0% of these deaths. The most commonly injured body area with critical trauma (AIS >/= 4) was the head (32.0%), followed by chest (20.8%), abdomen (11.5%), and extremities (1.8%). Time from injury to death was available in 2,944 of these trauma deaths. Overall, there were two distinct peaks of deaths: the first peak (50.2% of deaths) occurred within the first hour of injury. The second peak occurred 1 to 6 hours after admission (18.3% of deaths). Only 7.6% of deaths were late (>1 week), during the third peak of the classic trimodal distribution. Temporal distribution of deaths in penetrating trauma was very different from blunt trauma and did not follow the classic trimodal distribution. Other significant independent factors associated with time of death were chest AIS and head AIS. Temporal distribution of deaths as a result of severe head trauma did not follow any pattern and did not resemble classic trimodal distribution at all. CONCLUSIONS: The classic "trimodal" distribution of deaths does not apply in our trauma system. Temporal distribution of deaths is influenced by the mechanism of injury, age of the patient, and body area with severe trauma. Knowledge of the time of distribution of deaths might help in allocating trauma resources and focusing research effort.

Adult↗

PubMed2005

Differential expression of extracellular matrix remodeling genes in rat model of hemorrhagic shock and resuscitation.

BACKGROUND: Matrix metalloproteinases (MMPs) and their specific physiological inhibitors, tissue inhibitors of metalloproteinases (TIMPs), are thought to play an essential role in tissue repair, cell death and morphogenesis. We have previously discovered unexpected up-regulation of genes coding for multiple MMP/TIMP family members in a rat model of hemorrhagic shock and resuscitation. However, the effect of different resuscitation protocols at the level of protein expression and function remains unknown. MATERIALS AND METHODS: Male Sprague-Dawley rats (n = 50; 10/group) were subjected to a three-stage volume controlled hemorrhage and resuscitated as follows: 1) lactated Ringer's solution (LR), 3:1 volume of lost blood; 2) 7.5% hypertonic saline (HTS), 9.7 ml/kg; 3) plasma, 1:1 volume. Sham hemorrhage and sham resuscitation groups were used as controls. Expression of lung and spleen MMPs (-2, -7, -9, -10, -14, and -16), and TIMPs (-1, -2, and -3) was analyzed at transcriptional, functional and protein expression level using RT-PCR, ELISA, Western blotting, and gelatin zymography techniques. RESULTS: Spleen was affected more than lung by the resuscitation strategy and the largest number of changes was caused by HTS resuscitation. RT-PCR confirmed an increased levels of MMP-2, MMP-9, MMP-7, MMP-14, MMP-16, and TIMP-1, TIMP-2 in the spleen of HTS group compared to sham groups, whereas in lungs transcriptional levels of only TIMP-3 and TIMP-1 were significantly changed. CONCLUSION: Expression of MMP and TIMP in lung and spleen following hemorrhage is modulated by the resuscitation strategy.

Animals↗