Biomedical subjects
E L Dunn
Publications and source records attributed to E L Dunn.
Postgraduate trauma education; the surgeon; the cost.
Injuries account for 3.6 million hospital admissions and approximately 100 billion dollars in health care costs annually. Surgical educators have expressed concern about the adequacy of postgraduate trauma education in light of this trauma epidemic. The purpose of this report was to evaluate our residents' trauma exposure and to examine the associated cost of training a physician to treat critically injured patients. From July 1982 through June 1987, 38,714 patients were evaluated for injuries in the emergency department. Five thousand sixty-one patients required admission to the hospital, and of these, 2,045 were admitted to the intensive care unit. In addition, 3,851 major trauma operations were performed during this 5-year period. The majority of these procedures were neurosurgical and orthopedic; however, we have seen an increasing percentage of abdominal operations in the last 2 years. The last five graduating chief residents averaged 181 major trauma operations during their training. The hospital currently writes off an average of $250,000 per month in trauma patient non-collections. This averages to 1.5 million dollars per resident for 5 years of trauma education in our institution. It is imperative that we continue to train trauma surgeons to manage critically ill patients; however, society must address the enormous cost of doing so.
Cervical spinal cord injury--a public catastrophe.
Cervical spine cord injuries continue to be a major cause of death and disability for trauma victims. Motor vehicle trauma results in 500 to 650 quadriplegic patients per year. Most of the patients are cared for at Level I trauma centers which may not have a dedicated rehabilitation facility. Long-term rehabilitation, nursing care, and financial support remain difficult areas in the overall management of these injuries. Seventy-one cervical spine fracture patients were admitted to this medical center over a 2-year period. Twenty-two patients had a neurologic injury, 15 quadriplegic patients, and seven with incomplete deficits. Vehicular trauma was the etiology in 14 injuries; gunshot wounds in five; falls in three. Twelve of these 22 patients had associated injuries, including chest and abdominal trauma. Prolonged stays in the intensive care unit were common (avg. = 13.5 days). Bronchoscopy (8/22 patients) and aggressive pulmonary care were constantly needed. Six patients died in the intensive care unit. The average hospital stay of the survivors was 45 days. Three of the 16 surviving patients were ventilator dependent at the time of discharge. Ten patients were discharged to a rehabilitation center, one to a nursing home, and five went home (one on a ventilator). The total hospital charges were $1,250,000. No financial resources were available for five of the 16 surviving patients. Four patients had resources which covered less than 50% of the total charges. Average hospital charges for survivors were $50,370. Maximum reimbursement using all outlier days under DRG 5 would be $12,385. The financial support of initial hospitalization, rehabilitation, and nursing care for these quadriplegic patients is a serious national health care issue.
Community hospital to trauma center.
The Committee on Trauma of the American College of Surgeons published a report in 1976 charging hospitals to provide care for seriously injured patients. Implementing an effective emergency care/trauma system in a not-for-profit community hospital was a task that demanded leadership, substantial time, and commitment. The building process could not have begun without a strong commitment from the hospital's board, administration, medical staff, and nursing service. Initially, the operating rooms, radiology, intensive care units, and emergency departments were renovated or replaced. General surgeons and surgical subspecialists committed to trauma care were recruited. Emergency department (ED) physicians were upgraded and resident rotations in the ED were begun. A ground and helicopter transport system was initiated; dispatch was centered in the ED. Educational programs in prehospital critical care and stabilization for flight nurses and EMT's were developed. The operating rooms began 24-hour service with in-house anesthesia coverage. Radiology provided 24-hour coverage of specialty services. Physicians began in-house coverage of the critical care units. The department of surgery developed a trauma section to encompass all the general surgeons and subspecialty physicians in emergency care. Monthly in-service programs were begun for the intensive care unit (ICU) and ED nurses. In each of the past 3 years, a 2-day trauma update program has been provided to the regional Emergency Medical Services (EMS) and medical community. The dedication and commitment of many people during the past 5 years has resulted in a sound system of emergency/trauma care in a community hospital.
Percutaneous central venous catheters--a continuum of use.
Percutaneous central venous catheterization provides access for volume replacement and hemodynamic monitoring. This study reviewed 119 percutaneous central venous catheterizations in 112 patients over a 12-month period. All catheters were placed by emergency department (ED) physicians or housestaff under their direct guidance. Pneumothorax occurred in three patients and required chest tube insertion in one patient. Eighty-seven patients were admitted to the critical care units directly from the ED. In 26 (30%) patients, the central lines were converted to pulmonary artery catheters. Nineteen patients were admitted directly to the operating room, where the central venous line was used for volume replacement and monitoring. Postoperatively, five (26%) of these were converted to pulmonary artery catheters. Central venous catheters can be placed in patients percutaneously in the emergency department with minimal morbidity. They provide initial access to the central circulation for resuscitation and subsequently can be converted to pulmonary artery catheters for hemodynamic monitoring.
Computed tomography of the pelvis in patients with multiple injuries.
The extent of osseous pelvic injury in patients suffering multiple organ trauma is difficult to assess. However, accurate information is essential in order to determine an acceptable treatment regimen, either operative (external or internal fixation), or nonoperative (bed rest and early ambulation). Twenty consecutive patients were treated for pelvic fractures from January 1981 through February 1982. All patients had multiple organ injuries, (average = 3.5 organ systems per patient). Each patient had an A-P X-ray projection of the pelvis in the emergency department (E.D.) as a part of the initial evaluation. Three patients (15%) required immediate laparotomy for associated abdominal injuries. Six patients (30%) required prolonged ventilatory support for pulmonary injuries. Computed tomography (CT) of the pelvis was performed on all patients within 4 days of admission. In seven patients, CT examination confirmed the findings of the routine X-rays obtained in the E.D. In 13 patients the CT examination demonstrated significant additional fractures of the pelvis which were not initially demonstrated in the E.D. A consistent pattern of either sacral fracture or injury to the sacroiliac joint which was not appreciated on the initial E.D. X-rays was demonstrated in these 13 patients. Six patients underwent operative intervention, four with Hoffmann frames (external fixation), and two with reduction and internal fixation. CT examination of the pelvis provides a rapid and thorough evaluation which is extremely useful in demonstrating all the fractures of the pelvis on the single examination, thereby allowing the early determination of the best treatment plan for patients with such major injuries.
The effect of intravenous safflower oil emulsion on the clotting mechanism.
A new fat emulsion for intravenous use, derived from safflower oil (Abbott Laboratories), was studied. The clotting mechanism was compared with a battery of tests performed during the infusion of total parenteral nutrition (TPN) using glucose alone and during infusion of TPN using both glucose and fat. Five adult surgical patients underwent TPN with 7.0 per cent amino acid solution for ten days, receiving glucose as their only nonprotein calorie source on days one, two, nine, and ten (40 kcal/kg/day). On days three through eight, 10 per cent fat emulsion (600-900 ml/day) was given each day to provide one-third of the nonprotein calories. Simplate bleeding time, prothrombin time, activated partial thromboplastin time, fibrinogen (Biuret method), platelet count, platelet aggregation, serum functional antithrombin, and viscoelastic curves were measured on days one, three, six, and ten. Some of these studies were abnormal at baseline and during the study. No significant changes were seen with fat emulsion infusion. The patients did not exhibit any evidence of clinical bleeding. This new intravenous fat emulsion did not appear to be associated with alterations in the clotting mechanism. However, two of five patients showed increases in serum triglycerides and one patient died during the study.
Hemodynamic effects of aortic occlusion during hemorrhagic shock.
We investigated cardiac dynamics following temporary aortic occlusion during profound hypovolemia and abdominal distention. Control animals (N = 10) were bled from a femoral artery catheter to a systolic blood pressure of 60 mm Hg, while simultaneous abdominal distention was effected with intraperitoneal infusion of saline. After one hour of shock, thoracic aortic occlusion and immediate laparotomy were performed. The aorta was clamped for 20 minutes and then released over 5 minutes. The second group (N = 10) underwent the same procedure but received methylprednisolone sodium succinate intravenously at the time of aortic occlusion. During hypotension, mean arterial pressure, cardiac output, stroke volume, and stroke work decreased, while systemic vascular resistance increased. Aortic occlusion improved cardiac hemodynamics in the control group; in the steroid group these changes were even more pronounced. Measurement of dp/dt demonstrated ventricular contractility impaired during hypotension and improved during the period of aortic occlusion. Temporary thoracic aortic occlusion in the face of profound hypotension and massive abdominal distention improved cardiac function. The resulting increased afterload in this hypovolemic state was without deleterious effects. Furthermore, steroids appeared to enhance the cardiac response to aortic cross-clamping.
A feasibility study of computer aided diagnosis in appendicitis.
In this study, the hypothesis that computer aided diagnosis could enable a more accurate differentiation between patients with acute appendicitis and those with abdominal pain but normal appendixes was examined. A data base was established by analyzing the records of 476 patients having an emergency measure appendectomy during a five year period. There were 360 or 76 per cent with acute appendicitis, 98 or 20 per cent with normal appendixes and 18 or 4 per cent with other diseases requiring operation. The records were analyzed with regard to history, physical examination and laboratory findings. The data base was then divided randomly into two parts. Part 1 was subjected to univariate discriminant analysis, using the chi-square test. The only quantities which were significantly different between appendicitis and a normal appendix were sex, duration of symptoms, anorexia and vomiting. Multivariate discriminant analysis was used to derive an abdominal pain index which discriminated between appendicitis and a normal appendix with a sensitivity of 0.82 and a specificity of 0.39. Using the abdominal pain index to evaluate the patients in part 2 of the data base, 23 or 40 per cent of the 58 patients with a normal appendix would have avoided operation. However, 31 or 18 per cent of the 169 patients with appendicitis would have not been operated upon; three of those 31 had perforated appendixes. Computer aided diagnosis was no more effective than unaided clinical diagnosis in appendicitis.
The unnecessary laparotomy for appendicitis-can it be decreased?
There has been no decrease in the incidence of negative appendectomies in the adult population over the past two decades. Review of 484 appendectomies over a five-year period revealed that females between the ages of 13 to 40 have the lowest appendiceal perforation rate and the highest diagnostic error rate. More thorough preoperative assessment is indicated in this group. A program utilizing intensive observation, diagnostic barium enema, and laparoscopy may produce a reduction in negative laparotomies for appendicitis.
Immediate jejunostomy feeding. Its use after major abdominal trauma.
Jejunostomy feedings were used in the immediate postoperative period in patients with massive abdominal and retroperitoneal injuries. Patients were selected for early feeding if they had two or more major visceral injuries. Over a six-month period, 30 such patients were studied: ten had blunt trauma, 11 had gunshot wounds, and nine had stab injuries. The injuries included 11 pancreatic, ten small-bowel, six colon, and six major retroperitoneal vascular injuries. A 16-gauge intracatheter was placed in the proximal jejunum. The constant infusion of nutritional solution (Vivonex HN) was begun 18 hours postoperatively, and within 72 hours all patients were receiving 2,400 calories per day. Feedings were maintained for an average of eight days. Serum albumin and transferrin levels, total lymphocyte count, and delayed hypersensitivity were maintained or improved during jejunal feeding. Patients with pancreatic injuries received supplemental nutrition without evidence of pancreatic stimulation. Needle-catheter jejunostomy can provide early, safe nutritional support after major abdominal trauma. Further investigation is needed to determine who will benefit from this early feeding.
Acute alcohol ingestion and platelet function.
A substantial number of severely injured patients are under the influence of alcohol, making it important to understand the effects of acute alcoholic intoxication on the clotting mechanism. Twenty healthy volunteers ingested commercial liquor over a four-hour period and were observed for another three hours. Peak blood alcohol levels were above 200 mg/dL in four subjects and between 100 and 200 mg/dL in 12. Platelet counts, platelet aggregation, and bleeding times were not significantly altered over the seven hours. This study demonstrates that acute alcoholic intoxication in healthy persons does not alter platelet function.
Splenic, pancreatic, and hepatic injuries.
The preoperative resuscitation and operative management of hepatic trauma has vastly improved over the past 50 years. The majority of patients can be handled with simple techniques, with close attention to local hemostasis and adequate drainage. When major liver trauma does occur, exsanguination remains the leading cause of death. An integrated effort of physicians, nurses, and ancillary hospital support staff is needed to care for these severely injured patients.
Coagulation changes after albumin resuscitation.
The administration of albumin in the initial resuscitation of shock remains highly controversial. Impaired coagulation in the critically injured patient has recently been added as an argument against the use of supplemental albumin. This study investigated the hemostatic effects of albumin therapy after hemorrhagic shock. Twenty mongrel dogs were bled to a systolic pressure of 60 mm Hg for 1 h. After the return of shed blood, the animals received either lactated Ringer's solution or 5% serum albumin (25 ml/kg) daily for the 3 days. Coagulation parameters were measured before bleeding, immediately after resuscitation, and on days 2, 3, and 4. The changes in platelet count, platelet function, and serum fibrinogen were similar in the albumin treated and control animals. Although the prothrombin time and partial thromboplastin time were more prolonged in the albumin group, the changes were not sufficient to produce clinical bleeding.
Nutritional support of the critically ill patient.
Protein-calorie malnutrition is prominent among patients undergoing gastrointestinal tract operations who are admitted as an emergency measure to the intensive care unit. Immediate feedings postoperatively with an elemental diet through a jejunostomy catheter can provide an alternative method of nutritional support in these critically ill patients. In patients with extremely high metabolic demands, it may be necessary to combine enteral feeding with parenteral support to achieve positive nitrogen balance.
Amelioration of the pulmonary effects of massive autotransfusion with corticosteroids in the dog.
In this study, pulmonary changes were investigated following massive autotransfusion with local anticoagulation as well as whether or not corticosteroids would provide a protective effect. Twenty mongrel dogs were bled into the peritoneal cavity and autotransfused with the Sorenson system for a total of twice their blood volume. Blood was reinfused by means of 40 micron effective filters. Ten dogs were given 30 milligrams per kilogram of methylprednisolone sodium succinate at the time that autotransfusion was begun. Dogs of the control group had a decrease in cardiac output and oxygen delivery. Steroid-treated dogs had insignificant hemodynamic changes. Both groups showed a slight rise in pulmonary vascular resistance, but the arterial pO2 and pCO2 were unaltered. Two independent pathologists, in a blind study, examined the upper lobe of the left lung for hemorrhage, congestion, edema and fibrin thrombi. Nine of ten dogs in the control study had marked changes. A similar degree of alteration was recorded in only five of ten dogs in the steroid treated group. Corticosteroids mitigated the deleterious effects of massive autotransfusion in a canine model, and this may indicate their use in the critically injured patients undergoing this procedure.
Penetrating abdominal trauma index.
A method of quantifying the risk of complication following penetrating abdominal trauma is described. A trauma index score was calculated by assigning a risk factor (1-5) to each organ injured and then multiplying this by a severity of injury estimate (1-5). The sum of the individual organ scores comprised the final penetrating trauma index (P.A.T.I.). A consecutive series from 1975 to 1979 of 108 isolated stab wounds and 114 gunshot wounds to the abdomen requiring laparotomy were analyzed by this scheme. Only patients surviving 24 hours postoperatively were evaluated. Gunshot wounds resulted in P.A.T.I. scores greater than 25 in 39 (34%) of the patients. This was associated with a 46% complication rate and contrasted to a 7% incidence when the P.A.T.I. was equal to or less than 25. Following abdominal stab wounds six (6%) of the patients had P.A.T.I. scores exceeding 25. Complications developed in 50% of this group compared to 5% when the P.A.T.I. was less than 25. Using the P.A.T.I., we conclude that gunshot victims are more likely to need trauma center treatment than those with stab wounds. The P.A.T.I. also might facilitate cost analysis of trauma care. The ability to assess effects of patient age, sex, amount of blood loss, duration of hemodynamic shock, and metabolic response to injury might further enhance the therapeutic implications in both penetrating and blunt abdominal trauma.