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Biomedical subjects

S R Shackford

Publications and source records attributed to S R Shackford.

At least 109 records · Page 6Linked to original sources
PubMed1990

Venous thromboembolism in patients with major trauma.

The risk of venous thromboembolism after trauma is thought to be high, but the specific risk factors and the incidence of venous thromboembolism in the trauma population are poorly defined. Between October 1, 1987, and March 1, 1988, 719 patients were evaluated; 542 had no risk factors and 177 had at least 1 risk factor. No venous thromboembolism occurred in any of the 542 patients without a risk factor, whereas 12 of 177 patients (7%) with at least 1 risk factor had a venous thromboembolism. Pneumatic compression hose was the most common form of prophylaxis used, but it could not be applied to 35% of limbs because of plaster immobilizers, external fixators, complex wounds, or traction. In the high-risk group, 25 patients (14%) received no prophylaxis because of a physical impediment to application of these hose and a contraindication to anticoagulation. Age greater than 45 years was the only risk factor predictive of venous thromboembolism by logistic regression analysis. Patients with more than one risk factor had a significantly higher incidence of venous thromboembolism than those with only one risk factor. We conclude that a selected subgroup of trauma patients appears to be at risk of venous thromboembolism and should receive prophylaxis. Approximately one in seven high-risk patients cannot receive anticoagulant or mechanical prophylaxis because of their injuries.

Adult↗
PubMed1990

Management of splenic injuries.

The structure and function of the spleen are reviewed in the context of providing a rational basis for splenic salvage after trauma. Guidelines for operative and nonoperative management are provided, and the results of treatment from recent large series are summarized.

Adult↗
PubMed1990

Implications of admission hypothermia in trauma patients.

Hypothermia is common after severe injury, and has been associated with an increased mortality rate in patients stratified by anatomic indices of injury severity. In this retrospective study of 173 patients, early post-traumatic hypothermia was found to correlate with physiologic indicators of volume deficit, independently of the amount of intravenous fluid received. There was no correlation found between admission core temperature and time from injury, blood alcohol, or presence of severe closed head injury. Hypothermic patients (less than 35 degrees C) had a lower predicted probability of survival and a higher mortality rate than euthermic patients (greater than or equal to 35 degrees C). However, when patients were stratified by physiologic and anatomic indicators of injury severity, mortality rates among the euthermic and hypothermic patients were not significantly different. Early post-traumatic hypothermia does not appear to exert an independent effect upon outcome.

Adult↗
PubMed1990

The effects of aortic crossclamping and resuscitation on intracranial pressure, cerebral blood flow, and cerebral water content in a model of focal brain injury and hemorrhagic shock.

Aortic crossclamping (AOXC) is performed frequently in hypotensive trauma patients who may have had a head injury. The effect of AOXC on the injured brain is unknown. We studied the effect of AOXC on mean arterial pressure (MAP), intracranial pressure (ICP), cerebral blood flow (CBF), cerebral perfusion pressure (CPP), and cerebral water content in a porcine model of focal cryogenic brain injury. Four groups of animals were studied: Group I--brain injury only; Group II--brain injury and AOXC; Group III--brain injury with hemorrhage and AOXC; and Group IV--AOXC only. Focal cryogenic grain injury increased the ICP in Groups I-III. Aortic crossclamping increased MAP, CBF, ICP, and CPP after hemorrhage in Group III. Following declamping and resuscitation there were no differences between the groups in any studied variable. Cerebral water content at the site of the focal brain injury was greater than in nonlesioned cortex but there was no significant difference between groups despite a greater positive fluid balance in hemorrhaged animals. AOXC improved perfusion to the injured brain without a significant increase in ICP. Increased MAP induced by AOXC and large fluid resuscitation appeared to have no detrimental effect on ICP, CBF, cerebral water content, or CPP in this model of brain injury.

Animals↗
PubMed1990

Organ injury scaling, II: Pancreas, duodenum, small bowel, colon, and rectum.

The Organ Injury Scaling (O.I.S.) Committee of the American Association for the Surgery of Trauma (A.A.S.T.) has been charged to devise injury severity scores for individual organs to facilitate clinical research. Our first report (1) addressed O.I.S.'s for the Spleen, Liver, and Kidney; the following are proposed O.I.S.'s for Pancreas (Table I), Duodenum (Table II), Small Bowel (Table III), Colon (Table IV), and Rectum (Table V). The grading scheme is fundamentally an anatomic description, scaled from 1 to 5, representing the least to the most severe injury. We emphasize that these O.I.S.'s represent an initial classification system which must undergo continued refinement as clinical experience dictates.

Colon↗
PubMed1990

Blunt carotid artery dissection: incidence, associated injuries, screening, and treatment.

Blunt carotid dissection (BCD) is a rare injury occurring in less than one in 1,000 victims of blunt injuries. Using a 4-year experience in a trauma system with 14 cases of BCD, we performed a matched blunt trauma patient case-control analysis to determine if there were patterns of injuries that were associated with increased risk of BCD. Patients with combinations of head, facial, and cervical spine injuries with or without extremity fractures proved to be at significantly increased risk for BCD. Duplex scanning appears to be a useful screening tool for these patients. Anticoagulation was the preferred treatment once neurologic deficits were present.

Adult↗
PubMed1989

Intra-abdominal injury following blunt trauma. Identifying the high-risk patient using objective risk factors.

The initial physical examination is frequently unreliable in identifying patients with blunt trauma at high risk for having serious intra-abdominal injury. Intra-abdominal injury may be associated with specific injuries or risk factors, but the usefulness of such objective clinical criteria in predicting intra-abdominal injury has not previously been determined. The presence or absence of each of 11 clinical indicators and their association with serious intra-abdominal injury were analyzed in 3223 patients with blunt trauma. Linear and logistic regressions were used to determine which factors were significant predictors of an increased probability of intra-abdominal injury. Arterial base deficit less than -3 mEq/L, major chest injury, hypotension, and pelvic fractures were found to significantly increase the chance of intra-abdominal injury. Early diagnostic evaluation of the abdomen using diagnostic peritoneal lavage or computed tomography should be strongly considered in patients with blunt trauma who present with these associated factors.

Abdominal Injuries↗
PubMed1989

The impact of in-house surgeons and operating room resuscitation on outcome of traumatic injuries.

As trauma systems develop, more patients can potentially benefit from immediate surgery. With in-house surgeons available, enthusiasm for direct transfer from the scene to the operating room (OR) has developed in many institutions. The purpose of this study was to define precisely which patients should be taken to the OR for resuscitation. Three hundred twenty-three patients were taken to the OR directly from the field during a 4-year period (6.9% of trauma activations). Indications included the following: (1) cardiac arrest--one vital sign present, (2) persistent hypotension despite field intravenous fluid, and (3) uncontrolled external hemorrhage. A board-certified surgeon and resuscitation team met the field transport team in the OR in all cases. Cardiopulmonary resuscitation for patients with blunt trauma was not accompanied by survival even with immediate surgery by a trained surgeon and it wastes valuable OR resources. Patients with prehospital hypotension unresponsive to fluid resuscitation indicate the need for rapid surgery. Patients with blunt injuries even with hypotension infrequently undergo operations in less than 20 minutes and can be resuscitated in traditional areas where better roentgenograms are obtained. Penetrating injuries to the chest and abdomen with hypotension are the primary indications for OR resuscitation. It can be anticipated with field communication and accompanied by enhanced survival.

Heart Arrest↗
PubMed1989

Computed tomography in the diagnosis of traumatic rupture of the thoracic aorta.

Over a 26-month period, 25 patients admitted to the Trauma Unit at UCSD Medical Center following blunt trauma were investigated for suspected traumatic rupture of the thoracic aorta by computed tomography (CT) of the chest. A retrospective review of these patients was performed. Twenty-one (84%) also had CT of other body areas, most commonly the head or abdomen. Nine of the 25 patients subsequently had aortography; in 15 patients the CT findings were felt at the time to exclude rupture, and one patient was not investigated further because of severe head injuries. In general, if CT failed to show a mediastinal haematoma, aortography was not performed. However, five patients with CT evidence of a haematoma, including two with vertebral fractures, were not investigated by aortography. Two of the 25 patients (8%) had angiographically proven aortic ruptures; in both CT had shown not only a haematoma but also an abnormal outline of the aorta on contrast-enhanced scans. The haematoma was large in one patient and small in the other. Although 10 of the 25 patients had unenhanced scans, no case of aortic rupture is known to have been missed. During the same study period, 47 patients were investigated for suspected aortic rupture solely by aortography. Four patients (8% of this group) had aortic rupture, and two had subclavian or innominate artery ruptures. Only a minority (approximately one-quarter) also had CT of the head or abdomen. The role of CT in the diagnosis of traumatic rupture of the aorta is critically assessed in the light of our experience and a review of the literature.

Aorta, Thoracic↗
PubMed1989

Non-cavitary hemorrhage producing shock in trauma patients: incidence and severity.

Intraperitoneal and intrathoracic bleeding, cavitary hemorrhage (CH), are recognized as major causes of hypovolemic shock in trauma patients. Blood loss from fractures and lacerations, non-cavitary hemorrhage (NCH), is not considered a common cause of shock. Of 466 trauma patients admitted during a 12-month period without spinal cord injury, burns, or ongoing CPR, 13.1% were admitted in hypovolemic shock. Of these 466 patients 55.7% had strictly non-cavitary sources of blood loss, most commonly long bone fractures and skin lacerations. There was no significant difference in the resuscitative fluid requirements, morbidity, or mortality between patients presenting in hypovolemic shock due to CH and NCH. Blood loss from NCH must be recognized as a significant source of hypovolemic shock in trauma patients.

Adolescent↗
PubMed1989

Effect of a hypertonic lactated Ringer's solution on intracranial pressure and cerebral water content in a model of traumatic brain injury.

There has recently been an increased interest in the use of hypertonic solutions for fluid resuscitation of trauma victims. In this study, we examined the acute cerebral effects of a hypertonic lactated Ringer's solution (measured osmolality = 469 mOsm/kg) in an animal model of traumatic brain injury. Following the production of a cerebral cryogenic lesion, eight New Zealand white rabbits were randomized to undergo hemodilution with either lactated Ringer's (measured osmolality = 254 mOsm/kg) or hypertonic lactated Ringer's. Over the course of the experiment the lactated Ringer's group required significantly more fluid than the hypertonic group to maintain stable central venous and mean arterial pressure (245 +/- 5 ml vs. 132 +/- 20 ml; p less than 0.0001). Osmolality increased in the hypertonic group by 13.5 +/- 3.3 mOsm/kg whereas it decreased in the lactated Ringer's group by 5.5 +/- 2.6 mOsm/kg. Intracranial pressure increased in both groups over the course of the experiment but the increase in pressure was greater in the lactated Ringer's group than the hypertonic group (9.5 +/- 2.4 mm Hg vs. 1.7 +/- 1.5 mm Hg; p less than 0.001). Brain water content was significantly increased in the region of the lesion as assayed by both the wet/dry weight method and cortical specific gravity determinations, but there was no difference between the two treatment groups. Water content of the nonlesioned hemisphere was significantly less in the hypertonic group. This study suggests that hypertonic saline solutions may be useful for the resuscitation of hypovolemic patients with localized brain injury.

Animals↗
PubMed1989

Nonoperative management of blunt splenic trauma: a multicenter experience.

The experience of six referral trauma centers with 832 blunt splenic injuries was reviewed to determine the indications, methods, and outcome of nonoperative management. During this 5-year period, 112 splenic injuries were intentionally managed by observation. There were 40 (36%) patients less than 16 years old and 72 adults. The diagnosis was established by computed tomography in 89 (79%) patients, nuclear scan in 23 (21%), ultrasound in four (4%), and arteriography in two (2%). There were 28 Class I, 51 Class II, 31 Class III, two Class IV, and no Class V splenic injuries. Nonoperative management was unsuccessful in one (2%) child and 12 (17%) adults (p less than 0.05). Failure was due to ongoing hemorrhage in 12 patients and delayed recognition of pancreatic injury in one patient. Of the 12 patients ultimately requiring laparotomy for control of hemorrhage, seven (58%) were successfully treated with splenic salvage techniques. Overall mortality was 3%; none of the four deaths was due to splenic or associated abdominal injury. This contemporary multicenter experience suggests that patients with Class I, II, or III splenic injuries after blunt trauma are candidates for nonoperative management if there is: 1) no hemodynamic instability after initial fluid resuscitation; 2) no serious associated abdominal organ injury; and 3) no extra-abdominal condition which precludes assessment of the abdomen. Strict adherence to these principles yielded initial nonoperative success in 98% of children and 83% of adults. Application of standard splenic salvage techniques to treat the patients with persistent hemorrhage resulted in ultimate splenic preservation in 100% of children and 93% of adults.

Adolescent↗
PubMed1989

Thoracotomy during trauma resuscitations--an appraisal by board-certified general surgeons.

As trauma systems have developed and board-certified in-house surgeons are now immediately available, enthusiasm has returned for thoracotomy as part of initial resuscitation. This study evaluated the impact of thoracotomy by board-certified surgeons during the resuscitative phase of treatment. Resuscitative thoracotomy, performed on patients in cardiac arrest within 20 minutes of arrival in the hospital, was undertaken in 113 of 4,752 patients over a 4 1/2-year period. Resuscitative thoracotomy added nothing to beneficial survival in patients with a blunt mechanism despite the addition of a board-certified surgeon. Survivors of penetrating injury had a probability of survival (Ps) of 0.48. Most patients suffering penetrating deaths had severe and advanced physiologic derangements at the time of admission despite similar anatomic injuries to survivors.

Attitude of Health Personnel↗
PubMed1989

Epidemiology and pathology of traumatic deaths occurring at a Level I Trauma Center in a regionalized system: the importance of secondary brain injury.

We reviewed the hospital records and autopsy data of all deaths occurring at a Level I Trauma Center during a 1-year interval to determine the epidemiology of traumatic death in a regionalized system of care: 1,581 patients were admitted and 106 died (6.6%). Nonsurvivors (NS) differed significantly from survivors (S) in age, Trauma Score, Injury Severity Score, and probability of survival, but there was no difference between NS and S in scene time or transport time. Of the NS 91.4% died within 7 days; only 8.6% died after 7 days. Central nervous system (CNS) injury was responsible for 48.1% of deaths, followed by hemorrhage (36.8%) and cardiovascular disease (5.7%). Sepsis was responsible for 5.5% of deaths. Secondary brain injury was found at autopsy in 66% of patients dying of CNS injury. The relatively small number of septic deaths may be due, in part, to improvements in treatment associated with regionalization of trauma care. The frequency of secondary brain injury, despite rapid transport and evacuation of mass lesions, suggests that it may play a major role in the pathophysiology of CNS death occurring in a trauma system.

Adult↗
PubMed1989

Prospective analysis of carotid endarterectomy and silent cerebral infarction in 97 patients.

To determine the incidence of perioperative silent cerebral infarction, 97 patients who underwent carotid endarterectomy were prospectively studied with preoperative and postoperative computed tomograms. Thirty-one of 96 patients (32%) had findings of cerebral infarction on preoperative computed tomograms. Silent cerebral infarction was found preoperatively in 17 patients (18%) (lacunar infarction in 10, cortical infarction in five, both cortical and lacunar infarctions in one, and cerebellar infarction in one). Transient ischemic attacks occurred in 10 of the 17 patients with silent cerebral infarction; however, symptoms were appropriate to the site in only five of these 10 patients. Fourteen of the 17 patients with silent cerebral infarction had a hemodynamically significant carotid stenosis, and seven patients had an ulcerated plaque on preoperative angiogram. The incidence of these lesions was similar to that found in the group of 66 patients without cerebral infarction. Endarterectomy specimens revealed a higher but not significantly different incidence of ulcerated plaque in the silent cerebral infarction group. There were no perioperative deaths. Following surgery, one patient (1%) with a preoperative silent cerebral infarction suffered a transient ischemic attack, and two patients (2%) with normal preoperative computed tomograms developed permanent neurologic deficits with new cortical infarctions on postoperative computed tomograms. No new silent cerebral infarctions were found on postoperative computed tomograms in any of the 97 patients. Our data suggest that silent cerebral infarction is a common preoperative finding with an as-yet unclear etiology and that carotid endarterectomy does not appear to be a cause.

Aged↗
PubMed1989

Claudication in young adults: a frequently delayed diagnosis.

Arterial occlusive disease of the lower extremities is uncommon in young adults. Between 1983 and 1988 we undertook an aggressive approach to the diagnosis and treatment of claudication in young patients. Thirty-three patients (30 men and three women) with the onset of significant claudication at age 40 years or younger underwent arteriography after noninvasive evaluation. The mean duration of symptoms was 2 years, and six patients had suffered claudication for 4 years or longer. Atherosclerotic occlusive disease was found in 19 patients (58%), delayed presentation of traumatic occlusion was found in four (12%), congenital arteriopathy was found in four (12%), vasculitis was found in five (15%), and one patient (3%) had normal arteriogram results despite a history and physical examination that suggested inflow disease. Management included percutaneous transluminal angioplasty (PTA) in eight patients (24%) and operative reconstruction in 17 (52%). Seven patients (21%) were treated nonoperatively (five had unreconstructible distal disease and two declined operation). During a mean follow-up of 33 months, three patients who continued to smoke required either repeat PTA or operation for recurrent disease, one patient underwent repeat aortic reconstruction for early operative failure, and one patient with vasculitis required revision of an in situ vein graft for aneurysmal dilatation. The success rates of PTA and surgical reconstruction were encouraging. However, in the group with atherosclerotic occlusive vascular disease, the inability to abstain from smoking suggests a poor prognosis for long-term success.

Adult↗
PubMed1989

Organ injury scaling: spleen, liver, and kidney.

The Organ Injury Scaling (O.I.S.) Committee of the American Association for the Surgery of Trauma (A.A.S.T.) was appointed by President Trunkey at the 1987 Annual Meeting. The principal charge was to devise injury severity scores for individual organs to facilitate clinical research. The resultant classification scheme is fundamentally an anatomic description, scaled from 1 to 5, representing the least to the most severe injury. A number of similar scales have been developed in the past, but none has been uniformly adopted. In fact, this concept was introduced at the A.A.S.T. in 1979 as the Abdominal Trauma Index (A.T.I.) and has proved useful in several areas of clinical research. The enclosed O.I.S.'s for spleen, liver, and kidney represent an amalgamation of previous scales applied for these organs, and a consensus of the O.I.S. Committee as well as the A.A.S.T. Board of Managers. The O.I.S. differs from the Abbreviated Injury Score (A.I.S.), which is also based on an anatomic scale but designed to reflect the impact of a specific organ injury on ultimate patient outcome. The individual A.I.S.'s are, of course, the basic elements used to calculate the Injury Severity Score (I.S.S.) as well as T.R.I.S.S. methodology. To ensure that the O.I.S. interdiffuses with the A.I.S. and I.C.D.-9 codes, these are listed alongside the respective O.I.S. Both the currently used A.I.S. 85 and proposed A.I.S. 90 are provided because of the obligatory transition period. Indeed, A.I.S. 90 contains the identical descriptive text as the current O.I.S.'s. The Abdominal Trauma Index and other similar indices using organ injury scoring can be easily modified by replacing older scores with the O.I.S.'s.(ABSTRACT TRUNCATED AT 250 WORDS)

Abbreviated Injury Scale↗