Biomedical subjects

C M Dunham

Publications and source records attributed to C M Dunham.

16 recordsLinked to original sources

PubMed1992

Frequency of intra-abdominal injury in cases of blunt trauma to the cervical spinal cord.

Historically, early management of the blunt trauma victim with hemodynamic instability and cervical spinal cord injury has been hampered by the physician's inability to perform an accurate physical examination. Invasive and time-consuming diagnostic tests are often run to check for the presence of occult intra-abdominal injuries. For this reason, we decided to study these patients by reviewing a clinical registry to assess the frequency of intra-abdominal injuries in cases of cervical spinal cord trauma. We hypothesized that intra-abdominal injury would occur infrequently in cases of blunt trauma to the cervical spinal cord. In fact, data from the Maryland Institute for Emergency Medical Services Systems revealed that blunt trauma victims with cervical cord injury rarely (2.6%) sustained intra-abdominal wounds. Further analysis of this population revealed that specific mechanisms of trauma and the presence of hemodynamic instability and other major injuries were factors strongly associated with occult intra-abdominal injury. In light of these findings, we have outlined a protocol for management of these patients that is geared toward more rapid stabilization of the injured spinal column.

Abdominal Injuries↗

PubMed1991

The rapid infusion system: a superior method for the resuscitation of hypovolemic trauma patients.

The rapid infusion system (RIS), which can deliver fluids/blood products rapidly at precise rates and normothermic conditions, was compared with conventional fluid administration (CFA) in a randomized study of 36 hypovolemic trauma patients. Admission stratification criteria of the groups were similar relative to age, Glasgow Coma Score (GCS), Injury Severity Score (ISS) and plasma lactate. Despite the lack of difference in blood loss between the 24-h survivors of the two groups, the CFA group required greater total fluids (23.6/20.21), red blood cells (5.5/4.61), fresh frozen plasma (FFP) (2.8/1.91), platelets (523/204 ml), and crystalloids (12.9/10.61). Lactate levels were lower in the RIS group at virtually all times from hours 1 to 24 (4.3/5.3 mM/l, t-value = 3.3, DF = 279, P = 0.001). Post-admission hypothermia was greater in the CFA group at all times during the first 24 h (35.2/36.4 degrees C, t-value = 5.6, DF = 250, P = 0.001). The mean partial thromboplastin time was significantly higher in the CFA group (47.3/35.1 s, t-value = 3.1, DF = 279, P = 0.002). The PTT and PT were related to the degree of lactic acidosis (P = 0.0001) and hypothermia (P = 0.001) but not to the amount of FFP given (P = 0.14). The hospital costs, days in the ICU, and days on the ventilator were greater for the CFA group, as was the incidence of pneumonia (0/11 vs. 6/17; P = 0.03). Hypovolemic trauma patients resuscitated with the RIS needed fewer fluid/blood products and had less coagulopathy; more rapid resolution of hypoperfusion acidosis; better temperature preservation; and fewer hospital complications than those resuscitated with conventional methods of fluid/blood product administration.

Adult↗

PubMed1991

Oxygen debt and metabolic acidemia as quantitative predictors of mortality and the severity of the ischemic insult in hemorrhagic shock.

BACKGROUND AND METHODS: An experimental canine model of hemorrhagic, hypovolemic shock is described that uses oxygen debt and its metabolic consequences of lactic acidemia and metabolic base deficit as independent variables for the prediction of probability of death. RESULTS: Lactic acidemia and metabolic base deficit are compared with the conventional hemodynamic variables of BP and cardiac output (Qt) as predictors of outcome and are shown to be superior using a modified Kaplan-Meier probability statistic. The LD50 for oxygen debt is shown to be 113.5 mL/kg, 12.9 mmol/L for lactate, and -18.8 mmol/L for base excess (BE). Comparison is made between the ability of Qt, BP, shed blood, BE, and lactate to predict oxygen debt. CONCLUSIONS: Of the single-variable predictors, BE shows the highest explained variability. However, a combined prediction from both lactate and BE appears superior to the use of either alone. Using this regression to compute the oxygen debt, it is possible to estimate accurately the actual level of oxygen debt from the BE and lactate values obtained during hemorrhagic hypovolemia. From serial determinations over time of the increase in these biochemical variables above the oxygen debt baseline, it is possible to estimate the rate of oxygen debt accumulation and the time remaining until the LD50 will be reached as indicators of the severity of the total body ischemia resulting from hemorrhagic shock.

Acid-Base Equilibrium↗

PubMed1991

Outcome following prolonged intensive care unit stay in multiple trauma patients.

OBJECTIVE: To describe the hospital course and outcomes of trauma patients requiring ICU stays greater than 30 days and the charges they incur. DESIGN: A retrospective case series analysis of data collected from patient charts and trauma registry. SETTING: A Level I regional trauma center that is part of a statewide trauma system. PATIENTS: Over a 3-yr period, 87 patients (3% of all trauma ICU admissions) had prolonged stays (greater than 30 days) in the ICU; they constitute the study group. Blunt trauma was responsible for 90% of injuries, and the mean Injury Severity Score was 34 +/- 16 SD. RESULTS: Mechanical ventilation was required for 78.5% of the time spent in the ICU. The mean time spent on mechanical ventilators was 47 +/- 23 days; in the ICU, 60 +/- 27 days; and in the hospital, 72 +/- 29 days. Infectious complications occurred in 90% and organ dysfunction was seen in 76% of patients. The overall mortality rate was 17.2% (31% for patients greater than 65 yr). Patients less than 40 yr had lower mortality rates despite a significantly higher Injury Severity Score and lower Glasgow Coma Scale score compared with those greater than 65 yr. More patients greater than 65 yr were discharged to chronic care facilities than those younger (23% vs. 5%). The number of patients followed at 3 and 12 months after discharge was 74% and 54%, respectively, with only two deaths. The mean hospital and professional charges to the patients were $101,000 +/- 61,000 and $35,000 +/- 13,000, respectively. CONCLUSION: Length of ICU stay was most closely associated with the need for mechanical ventilation. The presence of premorbid illness, age greater than 65 yr, and organ dysfunction was associated with increased mortality. Although trauma patients requiring prolonged ICU stays utilize many resources, the ultimate outcome may be fairly good.

Adolescent↗

PubMed1991

Value of CT in determining the need for angiography when findings of mediastinal hemorrhage on chest radiographs are equivocal.

The role of CT in determining the need for angiography in patients with possible thoracic vascular injury resulting from blunt trauma is controversial. During a 24-month period, we prospectively evaluated the results of CT to screen 90 patients with a history of decelerating thoracic trauma for evidence of mediastinal hemorrhage or great vessel abnormality. All patients either had equivocally abnormal mediastinal contours on chest radiographs (64%) or had technically suboptimal chest radiographs owing to body habitus or restriction to the supine projection (36%). Patients with unequivocal signs of mediastinal hemorrhage on chest radiographs underwent immediate arteriography without prior CT. Thoracic CT was interpreted as normal in 63 (77%) patients and no further imaging was performed. Five patients had technically suboptimal CT studies, and CT scans were interpreted as equivocal in six. These 11 patients had normal arteriograms. Sixteen CT scans (18%) demonstrated evidence of mediastinal hemorrhage and/or great vessel contour abnormality. Four (27%) of 15 patients who underwent arteriography had injury to the great vessels. One patient refused to undergo angiography. In 11 patients with CT evidence of mediastinal hemorrhage, major vascular injury was not seen on arteriography. These results suggest a valuable role for CT in determining the need for arteriography to detect potential great vessel injury in patients with blunt decelerating thoracic trauma and equivocally abnormal mediastinal contours on chest radiographs.

Adult↗

PubMed1991

Hepatic insufficiency and increased proteolysis, cardiac output, and oxygen consumption following hemorrhage.

Thirty dogs underwent hemorrhage over a 60-min period to a predetermined O2 debt of 60-120 mL O2/kg, monitored with a Beckman metabolic cart, and then were resuscitated with 120% of the shed volume. Twenty survived and were followed over the next 7 days. On day 4, hepatic insufficiency was suggested by an elevation in [total amino acids] and [lactate] and a decrease in [urea] and [branched-chain amino acids]/[aromatic amino acids]. Net whole body catabolism on day 4 is suggested by a decrease in [glutamine] and an increase in plasma [3-methylhistidine], [phenylalanine], and [tyrosine]. These changes were significantly related to cardiac index, mean blood pressure, [lactate], O2 debt, and shed volume during the hemorrhage 4 days earlier. On day 7 there was a significant increase in the cardiac index and the VO2. These data suggest that hemorrhage induces sequelae similar to major injury or sepsis: hepatic insufficiency, net catabolism, hypermetabolism, and a hyperdynamic circulation. The hyperdynamic circulation may be necessary to meet increased tissue delivery requirements for O2 and amino acids.

Amino Acids↗

PubMed1991

Relationship of plasma amino acids to oxygen debt during hemorrhagic shock.

Thirty dogs underwent hemorrhage over a 60 minute period to a predetermined O2 debt of 60-120 mL O2/kg, quantified real-time by a Beckman metabolic cart; they were then resuscitated with 120% of the shed volume. The [total amino acids], [lactate], and [alanine]/[glutamine] rose during hemorrhage and resuscitation. Blood pressure, VO2, cardiac index, circulating amino acid pool, and systemic amino acid transport decreased during hemorrhage, but rose during resuscitation. The [total amino acids], [alanine]/[glutamine], cardiac index, blood pressure, and [lactate] were significantly related to O2 debt. The O2 debt during hemorrhage was substantially better related to [lactate] compared to shed volume or blood pressure. The changes in [total amino acids] and [alanine]/[glutamine] and their relationship to O2 debt suggest a hemorrhagic-induced alteration in tissue amino acid kinetics. These data further suggest that using a metabolic substrate parameter such as O2 utilization is useful to stratify other cellular alterations such as amino acid uptake and release and lactic acidosis.

Alanine↗

PubMed1991

The role of the Argon Beam Coagulator in splenic salvage.

To assess the effect of the Argon Beam Coagulator (ABC) (Bircher Medical Systems) on splenic salvage, 160 adults sustaining blunt traumatic splenic injuries over a 39 month period were evaluated. The survey period includes the first 15 months during which the ABC was used and the immediate 24 months before the use of the ABC (pre-ABC). In addition to the difference in splenic salvage in the two groups with deep laceration without hilar injury (15 versus 53 per cent), the Injury Severity Score (ISS) (44.2 versus 34.5) and Glasgow Coma Score (GCS) (11.4 versus 13.8) were significant. Multivariate logistic regression analysis revealed a significant relationship between splenic salvage and ISS (r2 = 0.27, p = 0.001) with ABC (r2 = 0.07, p = 0.02). However, if GCS is added to ISS and ABC as a factor, it does not provide additional information (p = 0.37). We conclude that the use of the ABC in the management of blunt nonhilar splenic injuries significantly improves the prospect for successful splenorrhaphy.

Adolescent↗

PubMed1991

Blunt traumatic rupture of the heart and pericardium: a ten-year experience (1979-1989).

Blunt traumatic rupture of the heart and pericardium, rarely diagnosed preoperatively, carries a high mortality rate. From 1979 to 1989, more than 20,000 patients were admitted to a Level I trauma center. A retrospective review identified 59 patients requiring emergency surgery for this condition. Injuries resulted from vehicular accidents (68%), motorcycle crashes (10%), pedestrians being struck by vehicles (7%), falls (5%), crushing (7%), and being struck by a horse (2%) or crane (2%). Seventeen patients (29%) had isolated rupture of the pericardium; 37 (63%) had ruptures of one or more cardiac chambers. All patients had signs of life at the scene or during transportation, but only 29 (49%) had vital signs on admission: 15 with chamber injury, 12 with pericardial rupture, and two with combined injuries. Diagnosis was established by emergency thoracotomy in the 30 patients who arrived in cardiac arrest. In the remaining 29 patients, diagnosis was made by urgent thoracotomy (41%), by subxiphoid pericardial window (34%), during laparotomy (21%), or by chest radiography (3%). The overall mortality rate was 76% (45 patients), but only 52% for those with vital signs on admission. Rapid transportation and expeditious surgical treatment can save many patients with these injuries.

Adolescent↗

PubMed1990

Blunt traumatic cardiac rupture. A 5-year experience.

Blunt traumatic cardiac rupture is associated with a high rate of mortality. A review of the computerized trauma registry (1983 to 1988) identified 32 patients with this injury (ages 19 to 65 years; mean age, 39.5 years; 21 men and 11 women). Twenty-one patients (65.6%) were injured in vehicular crashes, 3 (9.4%) in pedestrian accidents, 3 (9.4%) in motorcycle accidents; 3 (9.4%) sustained crush injury; 1 (3.1%) was injured by a fall; and 1 (3.1%) was kicked in the chest by a horse. Anatomic injuries included right atrial rupture (13[40.6%]), left atrial rupture (8 [25%]), right ventricular rupture (10[31.3%]), left ventricular rupture (4[12.5%]), and rupture of two cardiac chambers (3 [9.4%]). Diagnosis was made by thoracotomy in all 20 patients presenting in cardiac arrest. In the remaining 12 patients, the diagnosis was established in seven by emergency left anterolateral thoracotomy and in five by subxyphoid pericardial window. Seven of these 12 patients (58.3%) had clinical cardiac tamponade and significant upper torso cyanosis. The mean Injury Severity Score (ISS), Trauma Score (TS), and Glasgow Coma Scale (GCS) score were 33.8, 13.2, and 14.3, respectively, among survivors and 51.5, 8.3, and 7.0 for nonsurvivors. The overall mortality rate was 81.3% (26 of 32 patients), the only survivors being those presenting with vital signs (6 of 12 patients [50%]). All patients with rupture of two cardiac chambers or with ventricular rupture died. The mortality rate from myocardial rupture is very high. Rapid prehospital transportation, a high index of suspicion, and prompt surgical intervention contribute to survival in these patients.

Adult↗

PubMed1990

Sequencing LeFort fracture treatment (Organization of treatment for a panfacial fracture).

The types of midfacial fractures and their complexity were evaluated in admissions to the Maryland Institute of Emergency Medical Service Systems (MIEMSS) during the years of 1984 to 1988. Two hundred and sixty-eight LeFort fractures were treated and followed (3.2 percent of admissions). One half (50 percent) had skull fractures and 40 patients (15 percent) had LeFort, skull and mandibular fractures. Isolated nasoethmoidal fractures were observed in 176 patients and in 107 patients (39 percent) of patients with LeFort fractures. Isolated mandibular fractures were observed in 321 patients and in 104 patients with LeFort fractures (39 percent). Eleven percent of patients had midfacial, nasoethmoidal and frontal sinus fractures. Six percent of patients had midfacial, frontal bone, frontal sinus and nasoethmoidal fractures (Cranial Base Crush Syndrome). Twenty two percent of patients had LeFort and frontal sinus fractures. Reconstruction of multiple area injuries is simplified by a highly organized treatment sequence that conceptualizes the face in two groups of two units. Each unit is divided into sections, and each section is assembled in three dimensions. Sections are integrated into units and units into a single reconstruction. Conceptually, in each unit, facial width must first be controlled by orientation from cranial base landmarks. Projection is then (and often reciprocally with width) established. Finally, facial length is set both in individual units and in the upper and lower face. Soft tissue is considered the "fourth dimension" of facial reconstruction. Bone reconstruction should be completed as early as possible to minimize soft tissue shrinkage, stiffness and scarring of soft tissues in nonantomic positions.(ABSTRACT TRUNCATED AT 250 WORDS)

Fracture Fixation↗

PubMed1989

Patterns of organ injury in blunt hepatic trauma and their significance for management and outcome.

Analysis of 185 consecutive patients admitted to a trauma center (1983-1986) with blunt traumatic injury to the liver classified by severity of hepatic injury (I-V) has demonstrated that the pattern of associated organ injuries is a major determinant of the immediate resuscitation requirements, complications, and the ultimate outcome of patients with hepatic injury. When the significance of all injuries and major complications was evaluated using simultaneous ANOVA techniques, only brain and chest trauma together were significant (p less than 0.03) as injuries occurring in subsequently fatal cases for all classes of blunt hepatic injury. Sepsis (p less than 0.05) and ARDS (p less than 0.005) were significant complications associated with death in the patients who survived the initial operative intervention, and only brain deterioration and exsanguinating hemorrhage were significant (p less than 0.0001) as direct causes of death in all groups of patients. It was of interest that neither associated bowel, spleen, stomach, or pancreatic injuries had a significant difference in incidence between survivors and deaths. Overall, the most important single injury determining ultimate outcome was blunt traumatic injury of the brain. Review of the resuscitation and operative intervention strategies, postoperative complications, and causes of death shows that the interactions between the class of liver injury and the injuries to other organs, primarily brain and lung, are the determinant of the optimization of postinjury therapy of both a surgical and critical care nature.

Accidents, Traffic↗

PubMed1989

Pelvic fracture in multiple trauma: classification by mechanism is key to pattern of organ injury, resuscitative requirements, and outcome.

Three hundred forty-three multiple trauma patients with major pelvic ring disruption were studied and subdivided into four major groups by mechanism of injury: antero-posterior compression (APC), lateral compression (LC), vertical shear (VS), and combined mechanical injury (CMI). Acetabular fractures which did not disrupt the pelvic ring were excluded. The mode of injury was: MVA, 57.4%; motorcycle, 9.3%; fall, 9.3%; pedestrian, 17.8%; crush, 3.8%. The LC and APC groups were divided into Grades 1-3 of increasing severity. The pattern of organ injury: including brain, lung, liver, spleen, bowel, bladder, pelvic vascular injury (PVASI), retroperitoneal hematoma (RPH) and complications: circulatory shock, sepsis, ARDS, abnormal physiology, and 24-hr total fluid volume administration were all evaluated as a function of mortality (M). As LC grade increased from 1 to 3 there was increased % incidence of PVASI, RPH, shock, and 24-hr volume needs. However, the large incidence of brain, lung, and upper abdominal visceral injuries as causes of death in Grade 1 and 2 fell in LC3, with limitation of the LC3 injury pattern to the pelvis. As APC grade increased from 1 to 3 there was increased % injury to spleen, liver, bowel, PVASI with RPH, shock, sepsis, and ARDS, and large increases in volume needs, with important incidence of brain and lung injuries in all grades. Organ injury patterns and % M associated with vertical shear were similar to those with severe grades of APC, but CMI had an associated organ injury pattern similar to lower grades of APC and LC fractures. The pattern of injury in APC3 was correlated with the greatest 24-hour fluid requirements and with a rise in mortality as the APC grade rose. However, there were major differences in the causes of death in LC vs. APC injuries, with brain injury compounded by shock being significant contributors in LC. In contrast, in APC there were significant influences of shock, sepsis, and ARDS related to the massive torso forces delivered in APC, with large volume losses from visceral organs and pelvis of greater influence in APC, but brain injury was not a significant cause of death. These data indicate that the mechanical force type and severity of the pelvic fracture are the keys to the expected organ injury pattern, resuscitation needs, and mortality.

Accidents, Traffic↗

PubMed1989

Hypotension and bleeding with various anatomic patterns of blunt splenic injury in adults.

A retrospective study of 112 consecutive adult patients with blunt splenic lacerations was performed. All of the patients had operative grading of the splenic injuries according to a prospective protocol. Data on preoperative hypotension (systolic blood pressure of less than 100) and intraoperative splenic bleeding were collected from hospital records. Patients with subcapsular hematomas were excluded. Over-all, 55.4 per cent of the patients with splenic lacerations were hypotensive preoperatively and 76.6 per cent were noted to be bleeding from the spleen at operation. For injuries not involving the hilum, seven of 22 of the patients with Grade I injuries were hypotensive preoperatively versus 19 of 29 of the patients with Grade IV injuries (p = 0.025). Fourteen of 21 patients with Grade I injuries were noted to be bleeding at operation. Seventeen of 23 with Grade IV injuries were noted to be bleeding. This difference was not significant. Of the patients with injuries involving the hilum, 25 of 38 were hypotensive preoperatively and 25 of 29 were noted to be bleeding at operation. No difference in the incidence of hypotension or bleeding was found between superficial and deep hilar injuries. No significant difference was found between the active bleeding with hilar and nonhilar injuries (p = 0.19). For isolated splenic injuries (N = 36), the incidence of hypotension was 39 per cent. However, 79 per cent of the patients with isolated splenic injuries were noted to be bleeding at operation. Of 49 patients with nonisolated splenic injuries who had been hypotensive preoperatively, 72.9 per cent were found to be bleeding at operation. Of the 27 patients never hypotensive preoperatively, 78 per cent were noted to be bleeding at operation (NS). For isolated splenic injury also, no relationship was found between preoperative hypotension and the presence of operative bleeding. No significant correlation was found between preoperative hypotension or the anatomic grade of splenic injury and the incidence of bleeding found at operation. Even if computed tomographic scans can reliably grade splenic injuries, anatomic grade may not be a predictor of clinical behavior. Hypotension also failed to predict the occurrence of continued splenic bleeding.

Adolescent↗

PubMed1989

Methodologic approach for a large functional trauma registry.

The utility of a clinical trauma registry (TR) is directly related to the constituents of the data base and to the accuracy of the data, which is contingent on a carefully constructed data collection system. A TR was developed by traumatologists at a busy Level I trauma facility that predominantly receives patients having incurred blunt injury. Four dedicated data collectors gather the AP information within 24 to 48 hours after admission, with prompt Attending Surgical review for verification. Examples of data output prove this is a functional system. Using a careful methodologic approach for design and implementation, clinicians can create a large, functional trauma registry with many potential applications.

Data Collection↗

PubMed1988

Major bowel and diaphragmatic injuries associated with blunt spleen or liver rupture.

The incidence of major bowel and diaphragm injuries occurring in association with blunt spleen and liver ruptures in adults was studied. Of 142 patients with splenic injuries, five had major bowel injuries and 12 had diaphragmatic ruptures. Of 102 patients with blunt hepatic injury, 13 had either bowel or diaphragm ruptures or both. Six bowel and diaphragm injuries occurred in 42 patients with blunt ruptures of both the liver and spleen. Anatomically minor spleen injuries were associated with a 4.8% risk of bowel or diaphragm rupture. Anatomically major splenic lacerations had associated bowel or diaphragm wounds in 16.4% of cases (p = 0.024). A 20% incidence of partial-thickness bowel wounds was found in patients with hepatic or splenic injury, but the natural history of these wounds is unknown.

Adolescent↗