Screening Laboratory Testing in Asymptomatic Minor Pediatric Blunt Trauma Leads to Unnecessary Needle Sticks.

OBJECTIVE: Screening blood work after minor injuries is common in pediatric trauma. The risk of missed injuries versus diagnostic necessity in an asymptomatic patient remains an ongoing debate. We evaluated the clinical utility of screening blood work in carefully selected asymptomatic children after minor trauma. METHODS: Patients seen at a level 1 pediatric center with "minor trauma" for blunt trauma between 2010 and 2015 were retrospectively reviewed. Exclusion criteria were age <4 of >18 years, a Glasgow Coma Scale score of <15, penetrating trauma, nonaccidental trauma, hemodynamic instability, abdominal findings (pain, distension, bruising, tenderness), hematuria, pelvic/femur fracture, multiple fractures, and operative intervention. Data abstraction included demographics, blood work, interventions, and disposition. RESULT: A total of 1308 patients were treated during the study period. Four hundred thirty-three (33%) met inclusion criteria. Mean ± SD age was 12.7 ± 4 years (range, 4-18 years), and 59% were male. Seventy-eight percent were discharged home from the emergency department. All patients had blood work. Twenty-eight percent had at least one abnormal laboratory value. The most common abnormal blood work was leukocytosis (16%). Thirty percent had an intervention, and none prompted by abnormal blood work. One patient had an intra-abdominal finding (psoas hematoma). CONCLUSION: When appropriately selected, screening laboratory testing in asymptomatic minor pediatric blunt trauma patients leads to unnecessary needle sticks without significant advantage.

Holocord syringomyelia secondary to tethered spinal cord associated with anterior sacral meningocele and tailgut cyst: case report and review of literature.

BACKGROUND AND IMPORTANCE: Anterior sacral meningoceles are lesions that are uncommonly reported and can be associated with other pathology including presacral masses, tethered spinal cord, and syringomyelia. Tethered spinal cord and syringomyelia can result in neurologic deficits, while large meningoceles and presacral masses can have gastroenterologic, urologic, reproductive, and oncologic consequences. CLINICAL PRESENTATION: The authors report a case of a 14-year-old girl with an anterior sacral meningocele, tailgut cyst, and tethered cord with holocord syringomyelia who presented with a tethered cord syndrome, manifested by constipation, urinary retention, bilateral lower extremity weakness, and sensory deficits. After extensive radiographic and urodynamic workups were performed, the patient was treated by the neurosurgery and pediatric surgery teams with a posterior sagittal approach for cord detethering, resection of an intradural cystic mass, resection of the anterior sacral meningocele, and resection of the adjacent presacral mass. After surgical treatment, motor weakness and sensory deficits were resolved, though urinary symptoms persisted. The syrinx resolved after detethering alone. Pathology of the intradural cystic mass and the presacral mass inferior to the anterior sacral meningocele were consistent with tailgut cyst. CONCLUSION: The patient's clinical and surgical management are discussed, and a literature review related to anterior sacral meningoceles and their related pathologies is presented. An interdisciplinary approach is required for the best treatment of this constellation of findings.

Pneumomediastinum: A Rare Presentation of Inflicted Injuries in Infants.

Reports of incidental pneumomediastinum in infants secondary to inflicted trauma are limited. A retrospective review of infants with pneumomediastinum and history of inflicted trauma was performed. A comprehensive literature review was performed. Three infants presented with pneumomediastinum associated with inflicted trauma. Mean age was 4.6 weeks. All patients underwent diagnostic studies, as well as a standardized evaluation for nonaccidental trauma. All patients with pneumomediastinum were resolved at follow-up. Review of the literature identified other cases with similar presentations with related oropharyngeal injuries. Spontaneous pneumomediastinum in previously healthy infants may be associated with inflicted injuries. Clinicians should be aware of the possibility of an oropharyngeal perforation related to this presentation.

Laparoscopic Peritoneal Dialysis Catheter Placement with Chest Wall Exit Site for Neonate with Stoma.

Neonates requiring peritoneal dialysis (PD) catheters have been shown to have complication rates up to 70%. The presence of a concurrent stoma significantly increases the risk of peritonitis, exit-site infection, and catheter failure. As such, multiple techniques have been proposed to reduce these risks, including a chest wall exit site. In this case, the patient was born with bilateral hypoplastic kidneys and an anorectal malformation, requiring a colostomy soon after birth. At 4 weeks of life, he required placement of a PD catheter for dialysis. Given the high risk of infection, a laparoscopic-assisted PD catheter placement with a chest wall exit remote from the colostomy was performed. This report describes the operative technique including omentectomy, placement of a percutaneous stitch between the catheter cuffs, and fibrin glue injection around the catheter. The patient had no catheter-related infections. Laparoscopic-assisted PD catheter placement with chest wall exit site is a safe alternative in patients with any type of abdominal stoma.

Incidence and Outcomes of Perforated Peptic Ulcers in Children: Analysis of the Kid's Inpatient Database and Report of Two Cases Treated by Laparoscopic Omental Patch Repair.

INTRODUCTION: Peptic ulcer disease (PUD) is a rare condition in children. Perforated peptic ulcer (PPU), a complication of PUD has an estimated mortality between 1.3% and 20%. We evaluate incidence and outcomes of PPU in children using an administrative database, perform a review of the literature, and report our technique for laparoscopic omental patch repair for PPU in two pediatric patients. MATERIALS AND METHODS: Kids' inpatient database (KID's) was analyzed for demographics, incidence, and outcomes. Incidence for each year was calculated based on the reported pediatric population in the United States for 2000, 2003, 2006, 2009, and 2012 by the U.S. Census Bureau. Additionally, we present two PPU cases, accompanied by a comprehensive review of the literature. RESULTS: The annual number of primary discharge diagnosis of PPU in the KID was 178 cases for 2000, 252 for 2003, 255 for 2006, 299 for 2009, and 266 for 2012. An increase trend over time was noted between 2000 and 2009; however, it was not statistically significant (0.05). PPU appears to be more common in Caucasian teenage boys. The mean length of stay was 8.02 days and with a statistically significant increase in healthcare charges ($33,187 versus $78,142, P = .002) when comparing year 2000-2012. DISCUSSION: PPU is a rare cause of abdominal pain in children, but still a PUD complication that requires surgery. PPU should be included in the differential diagnosis in patients presenting with acute abdominal pain of uncertain etiology and pneumoperitoneum. Laparoscopy is both diagnostic and therapeutic. Laparoscopic omental patch repair is a safe and effective treatment for PPUs.

Bloody Stools in a 3-Day-Old Term Infant.

A 3-day-old term, male infant presented to the emergency department for evaluation of bloody stools. The infant was born after an uncomplicated pregnancy followed by a normal spontaneous vaginal delivery. The mother was group B Streptococcus colonized, and received antenatal penicillin prophylaxis. The infant received routine delivery room care, and was given ophthalmic erythromycin and intramuscular vitamin K. Circumcision was performed without bleeding and he was discharged from the newborn nursery and the hospital after 48 hours. On the day of presentation, he had streaky bright red blood in 4 consecutive stools. After discussion with the infant's pediatrician, the parents took him to the emergency department. The infant was afebrile, nursing well without emesis, and had made ∼10 wet diapers that day. The physical examination revealed a fussy infant with mild tachycardia, tachypnea, and scleral icterus. The complete blood count was unremarkable. Serum total bilirubin was 11.9 mg/dL, sodium 156 mmol/L, chloride 120 mmol/L, potassium 4.7 mmol/L, and bicarbonate 16 mmol/L. International normalized ratio was prolonged at 2.7, prothrombin time 26.6 seconds, partial thromboplastin time 38.9 seconds. The stool was hemeoccult positive. An obstructive radiograph series of the abdomen showed a nonobstructed gas pattern. Official radiology interpretation the following day reported possible pneumatosis intestinalis in the left and right colon. Our multidisciplinary panel will discuss the assessment of bloody stools in the term newborn, evaluation of electrolyte abnormalities, the diagnosis, and patient management.

Firearm injuries in the pediatric population: A tale of one city.

BACKGROUND: Firearm-related injuries are a significant cause of morbidity and mortality in children. To determine current trends and assess avenues for future interventions, we examined the epidemiology and outcome of pediatric firearm injuries managed at our region's two major pediatric trauma centers. METHODS: Following institutional review board approval, we conducted a 5-year retrospective review of all pediatric firearm victims, 16 years or younger, treated at either of the region's two Level 1 pediatric trauma centers, St. Louis Children's Hospital and Cardinal Glennon Children's Medical Center. RESULTS: There were 398 children treated during a 5-year period (2008-2013) for firearm-related injuries. Of these children, 314 (78.9%) were black. Overall, there were 20 mortalities (5%). Although most (67.6%) patients were between 14 years and 16 years of age, younger victims had a greater morbidity and mortality. The majority of injuries were categorized as assault/intentional (65%) and occurred between 6:00 pm and midnight, outside the curfew hours enforced by the city. Despite a regional decrease in the overall incidence of firearm injuries during the study period, the rate of accidental victims per year remained stable. Most accidental shootings occurred in the home (74.2%) and were self-inflicted (37.9%) or caused by a person known to the victim (40.4%). CONCLUSION: Despite a relative decrease in intentional firearm-related injuries, a constant rate of accidental shootings suggest an area for further intervention. LEVEL OF EVIDENCE: Prognostic and epidemiologic study, level IV.

Carotid revascularization in the presence of contralateral carotid artery occlusion is safe and durable.

OBJECTIVE: Complete occlusion of the contralateral carotid artery has been thought to increase the risk of carotid endarterectomy (CEA). This study was conducted to determine whether contralateral occlusion (CO) leads to a higher rate of complications among patients undergoing CEA or alters long-term outcomes. METHODS: All CEAs (N = 221) performed at our institution between September 1997 and June 2002 were reviewed. Patients were divided into two groups, i.e., CO and contralateral patency. Statistical analyses were performed using Fisher's exact test for nominal values and the t test for continuous variables. Life-table analyses were performed for patency and survival. RESULTS: Complete data and follow-up results were available for 170 of the 221 operations performed during the study period. CO was present in 16 cases (9.4%). Preoperative demographic features, indications for surgery, and operative techniques did not vary between study groups; there was increased use of general anesthesia (p = 0.05) in the CO group. No surgical deaths occurred. The perioperative stroke rates were not statistically different between groups (CO group, 6.3%; contralateral patency group, 2.6%; p = 0.39). Long-term patency and stroke-free survival rates at 5 years exceeded 90% and did not vary significantly between groups. CONCLUSION: Patients undergoing CEA with occlusion of the contralateral carotid artery do not have unique preoperative demographic features or indications. Contralateral carotid artery occlusion does not increase risk or alter long-term outcomes after CEA. Carotid revascularization can be safely performed in tertiary military centers.

Blood substitutes: hemoglobin-based oxygen carriers.

Blood product substitutes, particularly the hemoglobin-based oxygen carriers, represent one of the most exciting fields of research and development in modern medicine. The concept has been several decades in the making, and with products in phase III clinical trials, the use of hemoglobin-based oxygen carriers may be close to reality. The potential applications are limitless with interest from the military and civilian sectors.

Absence of clinical findings reliably excludes unstable cervical spine injuries in children 5 years or younger.

BACKGROUND: Increased accessibility and rapidity of computed tomography (CT) have led to increased use and radiation exposure to pediatric trauma patients. The thyroid is radiosensitive and therefore at risk for developing malignancy from radiation exposure during cervical spine CT. This analysis aimed to determine which preelementary trauma patients warrant cervical spine CT by defining incidence and clinical characteristics of preelementary cervical spine injury. METHODS: This was a retrospective review of pre-elementary trauma patients from 1998 to 2010 with cervical spine injury admitted to a Level I trauma center. Patients were identified from the trauma registry using DRG International Classification of Diseases-9th Rev. codes and reviewed for demographics, mechanism of injury, clinical presentation, injury location, injury type, treatment, and outcome. RESULTS: A total of 2,972 preelementary trauma patients were identified. Twenty-two (0.74%) had confirmed cervical spine injuries. Eleven (50%) were boys, and the mean (SD) age was 3 (1.7) years. The most common mechanism of injury was motor vehicle collision (n = 16, 73%). The majority (59%) were in extremis, and 12 (55%) arrived intubated. The median Glasgow Coma Scale (GCS) score was 3 (interquartile range, 3-10); the median Injury Severity Score (ISS) was 33 (interquartile range, 17-56). Nineteen injuries (76%) were at the level of C4 level and higher. The mortality rate was 50%. All patients had clinical findings suggestive of or diagnostic for cervical spine injury; 18 (82%) had abnormal neurologic examination result, 2 (9%) had torticollis, and 2 (9%) had neck pain. CONCLUSION: The incidence of cervical spine injury in preelementary patients was consistent with previous reports. Missing a cervical spine injury in asymptomatic preelementary patients is extremely low. Reserving cervical spine CT to symptomatic preelementary patients would decrease unnecessary radiation exposure to the thyroid. LEVEL OF EVIDENCE: Therapeutic study, level IV.

Resuscitation with a blood substitute causes vasoconstriction without nitric oxide scavenging in a model of arterial hemorrhage.

BACKGROUND: The purpose of this study was to determine if a hemoglobin-based oxygen carrier, HBOC-201 (Hemopure, Biopure Corp), alters endothelial function and nitric oxide physiology when used for hemorrhagic shock. STUDY DESIGN: Female swine (Sus scrofa) underwent catheterization of the femoral, circumflex iliac, and pulmonary arteries. Control animals (n = 3) underwent instrumentation only. Study animals underwent hemorrhage to mean arterial pressure of 30 +/- 5 mmHg, were maintained for 45 minutes, and resuscitated to the baseline mean arterial pressure for 4 hours. Resuscitation fluids included: shed blood (SB) (n = 8), lactated Ringers plus shed blood (LRSB) (n = 8), and HBOC (n = 8). At baseline, 1, and 4 hours after resuscitation, acetylcholine was infused into the proximal iliac artery and endothelial-dependent relaxation was measured with M-mode ultrasonography. Nitric oxide levels were determined using a chemiluminescent assay. RESULTS: HBOC, SB, and LRSB provided equivalent survival and resuscitation as measured by mean arterial pressures (65.3 +/- 2.48 mmHg); pulmonary artery mean pressures (15.8 +/- 0.84 mmHg); and lactate levels (1.22 +/- 0.19 mmol/L). HBOC group animals required the lowest resuscitation volume (SB, 41.5 +/- 3.5 mL/kg; LRSB, 76.4 +/- 1.1 mL/kg, HBOC, 14.6 +/- 2.1 mL/kg, p < 0.001). Response to acetylcholine was normal in the SB and LRSB groups, but the HBOC group had diminished acetylcholine response (29.5% endothelial-dependent relaxation end resuscitation, p < 0.001). Arterial nitric oxide levels did not differ between study groups (p = 0.69). CONCLUSIONS: HBOC might be an alternative resuscitation agent in patients with hemorrhagic shock. Resuscitation with HBOC requires less volume than blood or crystalloid. These data suggest HBOC-201 has a vasoconstrictive effect that cannot be attributed soley to nitric oxide scavenging.

Wartime vascular injuries in the pediatric population of Iraq and Afghanistan: 2002-2011.

BACKGROUND: Contemporary war-related studies focus primarily on adults with few reporting the injuries sustained in local pediatric populations. The objective of this study is to characterize pediatric vascular trauma at US military hospitals in wartime Iraq and Afghanistan. METHODS: Review of the Department of Defense Trauma Registry (DoDTR) (2002-2011) identified patients (1-17 years old) treated at US military hospitals in Iraq and Afghanistan using ICD-9 and procedure codes for vascular injury. RESULTS: US military hospitals treated 4402 pediatric patients between 2002 and 2011. One hundred fifty-five patients (3.5%) had a vascular injury. Mean age, gender, and injury severity score (ISS) were 11.1 ± 4.1 years, 79% male, and 34 ± 13.5, respectively. Vascular injuries were primarily from penetrating mechanisms (95.6%; 58.0% blast injury) to the extremity (65.9%), torso (25.4%), and neck (8.6%). Injuries were ligated (31%), reconstructed (63%), or observed (2%). Limb salvage rate was 95%. Mortality rate was 9%. CONCLUSIONS: This study is the first to report vascular trauma in a pediatric population at wartime. Vascular injuries involve a high percentage of extremity and torso wounding. Torso vascular injury in children is four times lethal relative to other injury patterns, and therefore should be considered in operational planning both in the military and civilian setting regarding pediatric vascular injuries.

Routine repeat brain computed tomography in all children with mild traumatic brain injury may result in unnecessary radiation exposure.

BACKGROUND: Computed tomography (CT) for pediatric traumatic brain injury (TBI) is common. Evidence suggests that 1 in 1,200 children undergoing CT will die of malignancy from radiation exposure. Presently, there is no protocol for surveying children with mild TBI; repeat CT (rCT) is often performed. We hypothesized that rCT could be avoided. Outcomes of similar patients who underwent rCT were compared with those of patients followed by clinical examination alone. METHODS: An 8-year retrospective review was performed of patients admitted to a Level I pediatric trauma center with TBI, CT evidence of TBI, and Glasgow Coma Scale (GCS) score of 14 to 15. There were two groups, those who underwent rCT (rCT+) and those who did not (rCT-). Data included age, Injury Severity Score (ISS), mechanism of injury, type of TBI, and outcome. Patients with coagulopathies, ventriculoperitoneal shunts, developmental disabilities, nonaccidental trauma, concomitant injuries, or medical problems resulting in intubation or sedation not attributed to TBI were excluded. RESULTS: Of 391 patients admitted with TBI, 120 were included in the study. A total of 106 patients were rCT+, and 14 were rCT-. rCT+ children were older (mean, 98.7 ± 7.3 vs. 35.3 ± 11.5 months; p = 0.0025) and more likely to have epidural hematoma (EDH) (100% rCT with EDH vs. 76% rCT all other TBI, p = 0.044). Mechanism of injury and mean ISS (15.2 ± 0.6 vs. 13.0 ± 1.1, p = 0.195) were not different between the groups. There were no worsening neurologic symptoms or need for surgery in rCT- children. rCT identified seven patients (6.6%) with CT progression of their injury. Five had an EDH, and two had a subarachnoid hemorrhage. Two children with EDH underwent operation. CONCLUSION: Our study indicates that routine rCT without evidence of clinical deterioration is not indicated in children with admission GCS score of 14 to 15 and TBI on CT scan. Children with EDH seem to have a higher potential for progression, and rCT seems to be indicated in this subgroup. LEVEL OF EVIDENCE: Therapeutic study, level IV.

A modified laparoscopic esophagogastric dissociation for severe bile reflux in a neurologically impaired child.

The clinical scenario of a neurologically impaired child with a prolonged history of gastroesophageal reflux disease that underwent open Roux-en-Y gastrojejunostomy with subsequent development of severe symptomatic bile reflux is reported. The presentation, evaluation, and surgical management by laparoscopic revision to a modified esophagogastric dissociation are discussed.

Modified ultrafiltration attenuates pulmonary-derived inflammatory mediators in response to cardiopulmonary bypass.

Cardiopulmonary bypass (CPB) stimulates systemic and pulmonary inflammation. Modified ultrafiltration (MUF) mitigates deleterious CPB effects by unclear mechanisms. We evaluated pulmonary inflammation in piglets undergoing CPB followed by MUF. Twenty-four piglets underwent 60 min of hypothermic CPB. MUF subjects (n=12) underwent hemoconcentration postCPB to the target hematocrit. Pulmonary vascular resistance (PVR), proinflammatory cytokine concentrations, and transpulmonary thromboxane gradients were determined at baseline, following CPB, and at end of the study (EOS) in MUF and control (n=12) groups. PVR significantly increased postCPB in both groups but decreased after MUF. MUF and control groups were similar in regards to systemic cytokine concentrations. Bronchoalveolar lavage concentrations of IL-6 and IL-8 significantly increased in controls throughout the study. Alveolar IL-6 and IL-8 were unchanged at EOS in MUF subjects, and IL-6 concentrations were significantly less than controls at EOS (P=0.015). Similarly, transpulmonary thromboxane gradient was significantly less at EOS in MUF subjects compared with controls (P=0.04). MUF removed circulating inflammatory mediators, lessened pulmonary hypertension, and reduced pulmonary-derived inflammatory markers, providing further evidence that MUF ameliorates pulmonary-based inflammation. These findings lend insight into mechanisms behind salutary clinical benefits of MUF after CPB.

Integrated DNA and fingerprint analyses in the identification of 60-year-old mummified human remains discovered in an Alaskan glacier.

This report describes the identification of a merchant mariner who perished in 1948 when Northwest Airlines Flight 4422, a DC-4 carrying 24 seamen and six crew members crashed into Mount Sanford, Alaska. Fifty-one years later, a human forearm and hand were found close by the wreckage of the plane, prompting identification efforts using DNA and fingerprints. There were significant challenges to both the fingerprint and DNA analyses. The hand was badly desiccated, making fingerprint friction-ridge detail almost invisible and the remains had been embalmed upon discovery, making DNA amplification difficult. We present the results of an interdisciplinary approach that successfully addressed these challenges and ultimately led to the identification of the remains. These efforts relied on efficient fingerprint rejuvenation and imaging techniques that improved print resolution, as well as new DNA extraction techniques optimized for aggressively embalmed remains.

Bilateral brachial artery occlusion decreases internal carotid artery volume flow: a simple adjunct for cerebral protection?

PURPOSE: To investigate if a decrease in internal carotid artery (ICA) blood flow occurs with bilateral brachial artery occlusion (BBO), which may improve the effectiveness of cerebral protection devices during carotid interventions. METHODS: Thirty-two asymptomatic patients (21 men; mean age 67 years) with carotid atherosclerosis between 15% and 79% were enrolled in the study. Carotid duplex ultrasound was followed by volume flow rate (VF) determination in the right ICA, external carotid (ECA), and vertebral arteries. After baseline values were obtained, BBO was induced by bilateral arm pressure cuff inflation to 30 mmHg over the systolic pressure for no more than 3 minutes. VF measurements were repeated. RESULTS: Seventeen patients (responders) had an ICA VF decrease from 406+/-109 mL/min (+/-SD) to 303+/-90 mL/min (p=0.005), while 15 patients (nonresponders) had no significant change in their ICA VF (340+/-192 versus 447+/-267 mL/min, p=0.22). In responders, ECA VF increased (190+/-65 to 232+/-125 mL/min), as did vertebral VF (77+/-53 to 95+/-60 mL/min; p>0.05). The ratio of ICA/ECA VF dropped from 2.13 to 1.31 in responders, but did not change in nonresponders. No patient exhibited any neurological symptoms during the study. Post cuff volume flows approximated baseline values. Cerebral magnetic resonance angiograms obtained in 10 responders revealed a complete circle of Willis in 8 (80%), while only 1 (16%) of 6 nonresponders had a complete pathway. CONCLUSIONS: A transient decrease in ICA VF, with concomitant elevations of the ECA and vertebral VFs, occurs with occlusion of the brachial arteries in the setting of a complete circle of Willis. Since no flow reversal occurs, this maneuver is insufficient to provide complete cerebral protection, but it may improve the effectiveness of cerebral protection devices and serve as an adjunctive maneuver in selected cases. Furthermore, changes in ICA VF may prove to be a noninvasive test for evaluating the integrity of the circle of Willis.

Endothelial dysfunction after lactated Ringer's solution resuscitation for hemorrhagic shock.

BACKGROUND: Endothelial dysfunction is presumed to occur after hemorrhagic shock and resuscitation. This study uses a novel large-animal model to evaluate the effects of diverse resuscitation regimens on endothelial function. METHODS: Twenty-seven adult domestic pigs (Sus scrofa) were used in this study. Control pigs (n = 3) underwent instrumentation alone. The remaining pigs experienced controlled hemorrhagic shock to a mean arterial blood pressure of 30 +/- 5 mm Hg for 45 minutes. Pigs were resuscitated to their baseline mean arterial blood pressure +/-5 mm Hg with either shed blood (SB; n = 8), lactated Ringers solution (40 mL/kg) followed by shed blood (LRSB; n = 8), or lactated Ringers solution alone (LR; n = 8). At baseline, 1 and 4 hours after resuscitation, acetylcholine (5, 10, and 15 microg/min) was infused into the proximal iliac artery to measure endothelial dependent relaxation (EDR). Sodium nitroprusside was infused to determine endothelial independent relaxation at the end of the study to insure smooth muscle vasomotor integrity. External iliac artery luminal diameter was measured using motion-mode ultrasonography. Statistical analysis was performed using repeated-measures analysis of variance with Tukey's post-hoc analysis. RESULTS: All pigs survived the experiment. Pigs required ninefold more resuscitation with LR (370.58 +/- 29 mL/kg) versus SB (41.45 +/- 3.5 mL/kg) or LRSB (76.4 +/- 1.1 mL/kg) (p < 0.05). EDR for LR pigs 1 hour after initiation of resuscitation (R1) was 70.4 +/- 14.4% compared with 94.2 +/- 13.4% for SB and 106.1 +/- 8.2% for LRSB (p < 0.05). At 4 hours after resuscitation (R4), systolic luminal diameters were larger in the SB (0.45 +/- 0.01 cm) and LRSB (0.51 +/- 0.02 cm) groups compared with LR (0.41 +/- 0.03 cm) (LRSB versus LR; p = 0.01). At R4, EDR for the LR group was 78.3 +/- 10.7% compared with SB (101.4 +/- 8.3%) and LRSB (106.4 +/- 7.4%) (p < 0.05). Infusion of sodium nitroprusside confirmed integrity of smooth muscle vasorelaxation. Analysis of serum nitric oxide levels revealed decreased values after resuscitation with LR (9.44 +/- 0.76 mol/L) compared with SB (26.3 +/- 7.8 mol/L) and LRSB (16.3 +/- 1.0 mol/L) (p = not significant). CONCLUSION: This is the first description of a large-animal model to evaluate EDR after hemorrhagic shock. Resuscitation with LR requires significantly larger volumes than SB or LRSB. LR resuscitation leads to endothelial dysfunction, as determined by decreased EDR, versus SB or LRSB. Resuscitation with blood products may preserve nitric oxide bioactivity when compared with crystalloid resuscitation in the setting of hemorrhagic shock.

Prolonged low-volume resuscitation with HBOC-201 in a large-animal survival model of controlled hemorrhage.

BACKGROUND: Military guidelines call for two 500-mL boluses of Hextend for resuscitation in far-forward environments. This study compared a hemoglobin-based oxygen carrier (HBOC-201; Hemopure) to Hextend when used to treat hemorrhagic shock in situations of delayed definitive care military operations. METHODS: Yorkshire swine (55-65 kg) were hemorrhaged to a mean arterial blood pressure (MAP) of 30 mmHg. Hypotension was maintained for 45 minutes followed by resuscitation with either Hextend (HEX) (n = 8) or HBOC-201 (HBOC) (n = 8). Over 8 hours, animals received up to 1,000 mL of either fluid in an effort to sustain an MAP of 60 mmHg. At the end of 8 hours, HEX animals received 2 L of lactated Ringer's solution followed by shed blood. HBOC animals received 4 L of lactated Ringer's solution only. Animals were killed and necropsied on postprocedure day 5. Hemodynamic data were collected during shock and resuscitation. Complete blood counts, amylase, lactate, coagulation studies, and renal and liver function were measured throughout the experiment. RESULTS: Equivalent volumes were hemorrhaged from each group (HBOC, 44.3 +/- 2.2 mL/kg; HEX, 47.4 +/- 3.0 mL/kg). The HBOC group achieved the goal MAP (HBOC, 60.0 +/- 2.3 mmHg; HEX, 46.4 +/- 2.3 mmHg; p < 0.01) and required less volume during the initial 8 hours (HBOC, 12.4 +/- 1.4 mL/kg; HEX, 17.3 +/- 0.3 mL/kg; p < 0.01). The HBOC group had lower SvO2 (HBOC, 46.3 +/- 2.4%; HEX, 50.7 +/- 2.5%; p = 0.12) and cardiac output (HBOC, 5.8 +/- 0.4 L/min; HEX, 7.2 +/- 0.6 L/min; p = 0.05), but higher systemic vascular resistance (HBOC, 821.4 +/- 110.7 dynes . s . cm-5; HEX, 489.6 +/- 40.6 dynes . s . cm-5; p = 0.01). Base excess, pH, lactate, and urine output did not differ between groups. HEX group survival was 50% (four of eight) versus 88% for the HBOC group (seven of eight). All animals survived the initial 8 hours. Animals surviving 5 days displayed no clinical or laboratory evidence of organ dysfunction in either group. CONCLUSION: HBOC-201 more effectively restored and maintained perfusion pressures with lower volumes, and allowed for improved survival. These data suggest that hemoglobin-based oxygen carriers are superior to the current standard of care for resuscitation in far-forward military operations.