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Biomedical subjects

L D Britt

Publications and source records attributed to L D Britt.

At least 73 records · Page 4Linked to original sources
PubMed2001

The usefulness of serum troponin levels in evaluating cardiac injury.

The diagnosis and clinical significance of blunt cardiac injury remains controversial. Cardiac troponin I is not found in skeletal muscle and has a high sensitivity for myocardial ischemia or injury. We hypothesized that normal troponin levels 4 to 6 hours postinjury would effectively exclude the diagnosis of cardiac contusion. A prospective evaluation of all blunt trauma patients older than 16 and admitted with the possible diagnosis of blunt cardiac injury was undertaken. Patients in whom this diagnosis was considered had an electrocardiogram (EKG) on admission, serum troponin, CPK and isoenzymes 4 to 6 hours postinjury, and admission with overnight telemetry. Other laboratory data and radiographic imaging was obtained as indicated. Seventy-two patients met criteria for entry into the study. Data was incomplete or inaccurately obtained on six patients, and they were excluded. Forty patients had normal troponins and normal EKG's on admission and were discharged the following day without any untoward effect. Sixteen patients were admitted with abnormal EKGs. All of these 16 patients had normal troponins 4 to 6 hours after their injury. They all did well and were discharged the following day. Ten patients had elevated troponins 4 to 6 hours after injury. One died two days later from refractory cardiogenic shock. Another was noted to have severely depressed left ventricular function by echocardiography. The other eight patients sustained no cardiac sequelae and were discharged once recovered from injuries. In the hemodynamically stable patient a normal troponin 4 to 6 hours after injury excludes clinically significant blunt cardiac injury. This holds true whether the admission EKG is normal or not. An elevated troponin does not definitively diagnose a clinically significant contusion. However, these patients should be monitored at least for 24 hours. Patients suspicious for cardiac contusions who have normal troponins and no other serious injuries may be safely discharged to go home from the emergency department.

Adult↗
PubMed2001

Blunt trauma and the role of routine pelvic radiographs.

We evaluated clinical factors that are predictive of pelvic X-ray findings. We sought to identify whether routine pelvic films are necessary in blunt trauma and addressed whether removal of these films would minimize cost. We performed a retrospective chart review of 111 patients without pelvic fractures and 108 with pelvic fractures seen at our Level 1 trauma center between August 1998 and September 1999. We evaluated initial hemodynamics, physical examination findings, laboratory data, and hospital charges. Patients with fractures had higher Injury Severity Scores (P < 0.001), a higher number of associated injuries (P < 0.001), and lower blood pressures (P < 0.001). The back and pelvic examinations were significantly associated with X-ray results (P < 0.001), and the potential savings with selective radiography was $168,300.00 per year. We believe that clinical factors identified in our study predict the need for pelvic X-ray. Because removal of these films would minimize cost we recommend the elimination of routine pelvic films for the awake and alert blunt trauma patient.

Adult↗
PubMed2000

Transient Horner's syndrome in a trauma patient with thoracic epidural analgesia: a case report.

Homer's syndrome, which classically presents as ipsilateral ptosis, meiosis, and facial anhydrosis, may present as a consequence of thoracic epidural analgesia. Pain that limits the patient's ability to maintain adequate pulmonary mechanics may optimally be treated with a thoracic epidural. The importance of recognition of a Horner's syndrome in such a patient is critical in preventing unnecessary anxiety for the patient and potentially embarking on an unnecessary diagnostic workup. The following is a case presentation of a patient who sustained multiple rib fractures in an automobile accident. The patient presented with a Horner's syndrome after a thoracic epidural infusion had begun. This article highlights the importance of early recognition of this benign, transient syndrome and discusses the pathways and potential mechanism of this process.

Accidents, Traffic↗
PubMed1998

"Alternative" surgery in trauma management.

Alternative" surgery in the trauma discipline essentially means nonoperative or a selective approach to the injured victim. Such an approach is a critical part of the trauma management options. However, it is unlikely that the term "alternative surgery" will be liberally used to depict this growing trend of nonoperative, selective, and minimally invasive trauma management because of its less than favorable connotations and biases with respect to alternative medicine. Although there are still clear indications for emergency operative intervention, the nonoperative or selective approach in both penetrating and blunt trauma is the state of the art.

Algorithms↗
PubMed1998

Interleukin-1 and interleukin-6 mediated skeletal muscle arteriolar vasodilation: in vitro versus in vivo studies.

Interleukin (IL) 1 and IL-6 have been implicated in the decreased systemic vascular resistance of septic shock; however, their sites of action and underlying mechanisms remain unclear. This study determined the effects of IL-1 and IL-6 on rat skeletal muscle arterioles using both in vitro and in vivo preparations. In the in vitro preparation, first order cremasteric arterioles were isolated from rats, cannulated with micropipettes, pressurized to 70 mmHg, superfused with physiologic saline solution, and allowed to achieve spontaneous basal tone in the absence of intraluminal flow. In the in vivo preparation, the cremaster muscle of anesthetized rats was surgically opened, secured as a flat sheet over an optical pedestal, and superfused with physiologic saline solution. Responses of third order arterioles were studied using transillumination video microscopy. In both arteriolar preparations, vessel diameter and phenylephrine (PE) responsiveness were assessed before and after cytokine exposure and washout. In vitro exposure of IL-1 (20 ng/mL (n=8) or 60 ng/mL (n=4)) or IL-6 (500 U/mL (n=2) or 1,000 U/mL (n=4)) for 1 h did not cause arteriolar vasodilation or change in PE responsiveness. However, during a 1 h in vivo exposure of IL-1 (.01, .1, 1.0, or 20 ng/mL), arteriolar diameter increased from 47+/-2 to 58+/-2% of maximum diameter (Dmax) (n=14, p < .0001), from 45+/-2 to 69+/-3% of Dmax (n=14, p < .0001), from 45+/-3 to 96+/-2% of Dmax (n=8, p < .0001), and from 47+/-4 to 96+/-1% of Dmax (n=14, p < .0001), respectively. Cytokine washout resulted in arteriolar return to basal diameter. Cytokine exposure and washout did not affect arteriolar PE responsiveness. In vivo exposure of IL-6 (10, 50, or 250 U/mL) for 1 h increased diameter from 47+/-2 to 57+/-2% of Dmax (n=14, p < .0001), from 46+/-2 to 75+/-3% of Dmax (n=14, p < .0001), and from 46+/-2 to 68+/-4% of Dmax (n=15, p < .0001), respectively. After washout of IL-6 (10, 50, or 250 U/mL), arteriolar dilation persisted, from 16.3+/-.5 to 20.1+/-1.4 microm (n=14, p < .003), from 16.1+/-.4 to 20.1+/-.6 microm (n=14, p < .0001), and from 17.7+/-.4 to 22.5+/-.8 microm (n=15, p < .0001), respectively. There was no change in PE responsiveness. These data indicate that the cytokines IL-1 and IL-6 are potent dilating agents for skeletal muscle resistance vessels under in vivo conditions. However, given that IL-1 and IL-6 are ineffective in causing relaxation of similar arterioles under isolated in vitro conditions, it is suggested that IL-1 and IL-6 interact with parenchymal or intravascular factors to elicit arteriolar relaxation.

Administration, Topical↗
PubMed1997

Blunt injury of the abdominal aorta: a review.

Injury to the abdominal aorta after blunt trauma occurs much less frequently than injury to the thoracic aorta. Although presentations vary, common themes continue to emerge with each patient. Within a 6-month period, our trauma unit diagnosed and treated two cases of blunt abdominal aortic trauma. Both patients were restrained passengers in motor vehicle crashes with resultant abdominal aortic injuries and demonstrated some of the most common associated injuries. Our two cases bring the number found in the literature to 62 and demonstrate the need for rapid recognition and treatment of this potentially lethal injury. This article is a comprehensive review of the management of abdominal aortic injury from blunt trauma.

Accidents, Traffic↗
PubMed1996

The effect of thyroid hormone supplementation on hemodynamic stability and survival in an endotoxin-induced model of physiologic stress.

Severe physiologic stress is associated with intense changes in the systemic hormonal milieu. Among these changes are suppression of the thyroid hormone axis resulting in decreased levels of triiodothyronine (T3) and thyroxine (T4). This study was conducted to determine whether supplemental T3 or T4 improved (1) hemodynamic stability and/or (2) survival following a standardized level of endotoxin (ET)-induced physiologic stress. Forty-eight hours after placement of internal jugular vein and carotid artery cannulas, male Sprague-Dawley rats (n = 91) were subjected to ET (15 or 20 mg/kg Salmonella enteritidis ET). Following an ET-induced decrease in mean arterial pressure (MAP), the animals received a continuous infusion of normal saline (NS), T3 (0.08, 0.4, or 2.0 micrograms/kg/hr), 0.4 microgram/kg/hr T3 in conjunction with 25 or 50 micrograms/min phenylephrine (PE), 0.4 microgram/kg/hr T3 and 5 micrograms/min dopamine, or 4.0 micrograms/kg/hr T4. There were no statistically significant differences in MAP during a 24-hr monitoring period among treatment groups. At 24 hr, there were no statistically significant differences in survival among animals treated with T3 alone (P > 0.05). Treatment with 4.0 micrograms/kg/hr T4 produced a 24-hr survival of 78% (versus 52% NS controls); however, this was not significant (P > 0.05). Phenylephrine administered in conjunction with T3 yielded a worse survival when compared to controls (0% versus 44%, P < 0.05); however, treatment with dopamine and T3 resulted in no change in survival at 24 hr (25%, P > 0.05). Within the dose ranges studied, T3 alone or in conjunction with dopamine or T4 alone did not improve hemodynamic stability or survival in an ET-induced model of physiologic stress. T3 in conjunction with PE resulted in a significantly worse survival after ET.

Animals↗
PubMed1996

Incidence and prophylaxis of deep vein thrombosis in a high risk trauma population.

BACKGROUND: Pelvic fractures, lower extremity injuries, acute head or spinal injury, and extended bedrest place trauma patients at an increased risk for deep vein thrombosis (DVT) and pulmonary embolism (PE). We reviewed patients with traumatic brain injuries (TBI), spinal cord injuries (SCI), and lower extremity fractures (LEF) to examine our DVT and PE incidence and evaluate the success of our DVT and PE prophylaxis. METHODS: From January 1, 1994 to March 1, 1995, the records of trauma patients with TBI, SCI, and LEF who were admitted to the trauma service and transferred to an inpatient rehabilitation facility were reviewed. RESULTS: Twenty-two patients had a TBI, 16 patients with SCI, and 12 patients with LEF. Forty-nine of the 50 patients received DVT prophylaxis, with 7 inferior vena cava (IVC) filters placed. The DVT incidence was 6% and the PE incidence was 2%. CONCLUSION: The 6% incidence of DVT was lower than expected due to diligent DVT prophylaxis and appropriate screening of symptomatic patients for clinically significant DVT. The 2% incidence of PE was also lower than expected, most likely due to our lower DVT incidence and the use of IVC filters. The lower DVT and PE incidence verifies our success at DVT and PE prophylaxis.

Adult↗
PubMed1996

Priorities in the management of profound shock.

This article discusses many of the aspects of profound shock, including historical perspectives on the concept of shock, the meaning of profound shock, and pathophysiology in shock. Organ systems in shock and methods of shock management also are presented.

Brain↗
PubMed1996

Endotoxin interacts with tumor necrosis factor-alpha to induce vasodilation of isolated rat skeletal muscle arterioles.

Sepsis is characterized by decreased peripheral vascular resistance, however, discrepancies exist regarding the specific secondary mediators involved. This study examined whether the presence of endotoxin (ET) is a requirement for tumor necrosis factor-alpha (TNF-alpha) to induce vasodilation of isolated skeletal muscle arterioles. First order cremasteric arterioles were isolated from male Sprague-Dawley rats, cannulated with glass micropipettes, superfused in physiologic saline, and allowed to achieve spontaneous basal tone in the absence of intraluminal flow. A 2 min exposure to TNF-alpha (.01-100 ng/mL) had no apparent effect on arteriolar diameter (95 +/- 5% after .01 ng/mL and 92 +/- 6% after 100 ng/mL, p > .05 compared with basal). However, arterioles superfused with 2.5 micrograms/mL Salmonella enteritidis ET for 1 h followed by a 2 min exposure to 100 ng/mL TNF-alpha demonstrated a dilation (to 128 +/- 12%) that became statistically significant 10 min after TNF-alpha washout (to 142 +/- 12%, p < .05). This effect was eliminated by combined inhibition of cycloxygenase (with indomethacin) and nitric oxide synthase (L-NAME). The data indicate that neither ET or TNF-alpha alone elicit a direct vasomotor effect on the isolated arteriole preparation used in these studies. However, pretreatment of the vessels with ET results in the ability of TNF-alpha to cause arteriolar dilation, possibly through a mechanism involving both cyclooxygenase and nitric oxide synthase.

Animals↗
PubMed1995

Angiosarcoma of the breast. Initial misdiagnosis is still common.

Primary angiosarcoma of the breast is a rare and often misdiagnosed disease. The most common clinical presentation is a painless mass in the affected breast, but the often varied presentation and the high incidence of histologic misdiagnosis make early detection rare. The tumor size and the histologic type correlate with the prognosis. The treatment for angiosarcoma of the breast is early and complete surgical excision of the mass with adequate margins. Axillary dissection is not indicated because the predilection for nodal metastasis is rare. The definitive role of adjuvant therapy remains undetermined. Chemotherapy and radiotherapy may play an important role in survival; however, the data are inconclusive. A high index of suspicion for angiosarcoma is a crucial tool in its proper diagnosis and treatment. It should always be noted that a vascular lesion that is associated with any breast mass is an angiosarcoma until proven otherwise.

Adult↗
PubMed1995

Lack of direct endotoxin-induced vasoactive effects on isolated skeletal muscle arterioles.

Septic shock continues to be a major cause of mortality in the intensive care unit. This study was conducted to determine if endotoxin exerts a direct effect on the major determinant of peripheral vascular resistance, skeletal muscle arterioles. First order cremasteric arterioles were isolated from male Sprague-Dawley rats, cannulated with glass micropipettes, superfused in physiologic saline solution, and allowed to achieve spontaneous basal tone in the absence of intraluminal flow. Phenylephrine responsiveness was assessed before and after exposure to 2.5 micrograms/mL Salmonella enteritidis endotoxin (ET) for 1-2 h. There was no change in either basal diameter (91 +/- 5 microns before ET and 98 +/- 5 microns after ET) or phenylephrine responsiveness. In vivo exposure to ET (15 mg/kg) resulted in no change in basal tone at 1 h, however increased tone was observed in arterioles harvested after 4 h of systemic ET (43 +/- 4% without ET and 57 +/- 3% with, p < .05). To determine if upstream conduit vessels released factors responsible for the vasodilation of skeletal muscle arterioles, isolated cannulated cremasteric arterioles were connected in series to a 1 cm segment of aorta and superfused without and with 2.5 micrograms/mL ET. An increase in basal diameter was observed in arterioles from 94 +/- 14 microns before ET to 120 +/- 17 microns after ET (p < .05). These studies demonstrate that ET has no direct effect on isolated cannulated skeletal muscle arterioles, and that a vasodilating substance not consistent with nitric oxide is released from the upstream arterial bed.

Animals↗
PubMed1994

High-voltage electrical injury: a role for mandatory exploration of deep muscle compartments.

Patients sustaining high-voltage electrical burns involving the upper extremities were evaluated for deep muscle compartment necrosis by early surgical exploration. Following resuscitation, patients were taken to the operating room where mandatory exploration of volar and extensor forearm and hand compartments was done to evaluate muscle viability. It was observed that deep muscle layers sustained the greatest thermal injury and that extended fasciotomies were required to obviate compartment syndrome and the potential for continued ischemia. Although 10 emergency amputations were required for six patients, those who underwent extensive exploration of their forearms and hands did not require subsequent amputation for nonviable extremities during second-look operations. These observations support the role for early exploration with generous exposure of deep muscle compartments to access and treat the thermal injury that results from high-voltage burns.

Adolescent↗
PubMed1994

Indolent carcinoid tumor of the sigmoid colon.

Carcinoid tumors of the colon are a rare cause of colonic malignant disease. A case of carcinoid tumor of the sigmoid colon is presented that illustrates the indolent course of this type of tumor. The case presented highlights the clinicopathologic features of carcinoid tumors of hindgut origin, including advanced local and widely metastatic disease at the time of diagnosis in the absence of symptoms of the carcinoid syndrome. The diagnosis and management of gastrointestinal carcinoid tumors are reviewed.

Carcinoid Tumor↗