Burn injury in patients with early-onset neurological impairments: 2002 ABA paper.

Many patients suffer from sensorimotor deficits that may contribute to burn injury. This retrospective study examines burn injuries in the subgroup of patients that suffer from the early onset neurological impairments of mental retardation, cerebral palsy, spina bifida, autism, and attention deficit-hyperactivity disorder. Fifty-one patients who suffered from the above-mentioned early-onset neurological impairments were admitted to our burn center during a 4-year period. The average TBSA burned was 8.9% yet resulted in prolonged hospitalizations. This study describes our burn center's experience in treating patients admitted with early-onset neurological impairments.

Effect of trauma system maturation on mortality rates in patients with blunt injuries in the Finger Lakes Region of New York State.

BACKGROUND: New York State instituted a statewide trauma system beginning in 1990. By 1993, that system included uniform emergency medical system triage guidelines, designated trauma centers, transfer agreements between trauma centers and noncenters, and a trauma registry containing data on seriously injured patients in each region and the state as a whole. We reviewed the first 4 years of registry data for the Finger Lakes Region to determine what effects the institution of a trauma system has had on the outcome of trauma care in this region. DESIGN: Retrospective review of a regional trauma database. METHODS: All qualifying injured patients in the region were entered into the registry beginning in 1993. Data from 1993 through 1996 for patients with blunt injuries were analyzed by both Trauma and Injury Severity Score (TRISS) methodology and logistic regression analysis. For comparison, two time periods were defined: 1993-1994 and 1995-1996. Outcomes for the two time periods were stratified by Revised Trauma Score and the presence or absence of head and/or cervical spine injury, and then compared by hospital type (regional trauma center, area trauma center, and noncenters). RESULTS: In the later time period, there was a statistically significant decrease in the region-wide mortality rate. This was associated with a marked improvement in performance of the noncenters and with an increase in the proportion of patients who received definitive care at a trauma center. CONCLUSIONS: Improved outcomes for patients with blunt trauma can occur early in the implementation of a trauma system. This improvement may be attributable in part to changes in field triage and early transport to trauma centers.

An examination of the volume-mortality relationship for New York State trauma centers.

OBJECTIVES: New York State Trauma Registry data were analyzed to determine whether there is a significant relationship between the volume of trauma patients treated by a trauma center and its risk-adjusted inpatient mortality rate. METHODS: Stepwise logistic regression was used to identify significant independent predictors of mortality, their weights, and the probability of in-hospital mortality for each patient. These data were then used to calculate risk-adjusted mortality rates for various ranges of hospital volume. Ranges were identified on the basis of homogeneity of mortality rates, the number of hospitals in each range, and the number of patients in each range. Three volume measures were used: (1) total annual volume of trauma cases > or = 1200 and total annual volume > or = 240 for patients with Injury Severity Score (ISS) > or = 15 (equivalent to American College of Surgeons [ACS] criteria), (2) total annual volume of patients with ISS > or = 15, and (3) total annual volume of cases in the Registry (approximately, inpatients with ISS > or = 9). RESULTS: Results show that the 35 New York State trauma centers not meeting the ACS criteria had lower, but not significantly lower, observed and risk-adjusted mortality rates (7.62% and 8.25%, respectively) than the corresponding rates for the 8 New York State trauma centers that met the ACS criteria (9.36% and 8.83%, respectively). Regarding the other two criteria, hospital ranges representing lower annual volumes tended to have somewhat lower, although not significantly lower, observed and risk-adjusted mortality rates. For example, using a total annual volume for patients with ISS > or = 15, the risk-adjusted mortality rates for the volume ranges 1-150, 151-250, and 251+ were 7.78%, 9.23%, and 8.70%, respectively. CONCLUSIONS: We were unable to document an inverse relationship between hospital volume and inpatient mortality rate for trauma centers in New York State. Volume criteria should not be considered indicators of the quality of trauma care.

Accounting for intubation status in predicting mortality for victims of motor vehicle crashes.

BACKGROUND: Two of the important predictors of mortality for trauma patients are the Glasgow Coma Scale and the respiratory rate. However, for intubated patients, the verbal response component of the Glasgow Coma Scale and the respiratory rate cannot be accurately obtained. This study extends previous work that attempts to predict mortality accurately for intubated patients without using verbal response and respiratory rate. METHODS: The New York State Trauma Registry was used to identify 1994 and 1995 victims of motor vehicle crashes (MVCs). For the subset of patients who were not intubated, we developed two statistical models to predict mortality: one did not contain verbal response or respiratory rate, and the other contained a predicted verbal response. These were compared with a model that did include verbal response and respiratory rate. We also compared the predictive abilities of the first two models for all MVC patients (intubated and nonintubated) and determined the extent to which intubated patients were at increased risk of dying in the hospital after having adjusted for other predictors of mortality. RESULTS: For nonintubated patients, the statistical model without verbal response and the model with predicted verbal response had slightly better discrimination and worse calibration than the model that included verbal response and respiratory rate. Predicted verbal response did not improve the strength of the model without verbal response. For all MVC patients (intubated and nonintubated), predicted verbal response was not a significant predictor of mortality when used in combination with the other predictors. Intubation status was a significant predictor, with intubated patients having a higher probability of dying in the hospital than patients with otherwise identical risk factors. CONCLUSION: Inpatient mortality for intubated MVC patients can be accurately predicted without respiratory rate or verbal response. There appears to be no need for predicted verbal response to be part of the prediction formula, but intubation status is an important independent predictor of mortality and should be used in statistical models that predict mortality for MVC patients.

Predictors of mortality in adult patients with blunt injuries in New York State: a comparison of the Trauma and Injury Severity Score (TRISS) and the International Classification of Disease, Ninth Revision-based Injury Severity Score (ICISS).

BACKGROUND: The purpose of this study was to determine the statistical model that best predicted mortality from blunt trauma using a contemporary population-based database. METHODS: 1994-1995 New York State Trauma Registry data for patients with blunt injuries were used to predict mortality using three statistical models: (1) the original Trauma and Injury Severity Score (TRISS) model based on Major Trauma Outcome Study data, (2) a new TRISS model whose coefficients were derived using New York data, and (3) the International Classification of Disease, Ninth Revision-based Injury Severity Score (ICISS) with predicted survival values obtained from the Agency for Health Care Policy and Research's Health Care Utilization Project. The models were compared with respect to discrimination (using the C statistic) and calibration (using the Hosmer-Lemeshow [H-L] statistic). In addition, the models were tested to see how well they predicted outcomes for each of the three mechanisms of blunt injury. RESULTS: The ICISS model had a significantly higher C statistic (0.878) and a better H-L statistic (29.38) for predicting mortality for all adult patients with blunt injuries. The original TRISS model had very poor calibration (H-L = 687.38). None of the three models predicted mortality accurately for victims of motor vehicle crashes or victims of low falls. When separate models were developed for all motor vehicle crashes, low falls, and other blunt injuries, the ICISS and New York TRISS models both fit well, although the calibration was marginal in most cases. The ICISS model had a statistically significantly higher C statistic for other blunt injuries and for motor vehicle crashes. The New York TRISS model had better calibration for low falls. CONCLUSIONS: The ICISS has promise as an alternative to TRISS, but many more comparative studies need to be undertaken using updated TRISS coefficients. Models should also be developed for mechanisms of injury, not just for blunt and penetrating injuries.

The Kidney's role in glucose balance following partial hepatectomy.

It has long been believed that the liver is the major contributor to glucose balance during fasting and stressful situations. Recently, investigators have implicated the kidney as having a significant contribution to systemic glucose appearance. We studied the relative contributions of the kidney and liver to glucose homeostasis in fasted nonoperated, sham-operated, and 70% hepatectomized rats. Systemic glucose appearance, renal glucose release and uptake, and hepatic glucose release were determined by glucose balance and isotopic dilution techniques. Systemic glucose appearance remained unchanged following hepatectomy. There was a significant output of glucose by the kidney in all groups, accounting for >50% of total glucose appearance. Despite the kidney's appreciable contribution to circulating glucose in the postabsorptive state, renal glucose release was not increased in the hepatectomized rats compared to controls. Total glucose appearance was maintained following hepatectomy by an increase in hepatic glucogenesis. There was a significant increase in the rate of hepatic glucose release from resected rats when normalized to gram of remaining liver (P < 0.001). Despite the substantial amount of renal glucose output in the postabsorptive state, preservation of glucose balance following 70% hepatectomy is accomplished by adaptation in hepatic glucose output.

Effectiveness of helicopter versus ground ambulance services for interfacility transport.

BACKGROUND: Helicopters provide rapid interfacility transport, but the effect on patients is largely unknown. METHODS: Patients requested to be transported between facilities by helicopter were followed prospectively to determine survival, disability, health status, and health care utilization. A total of 1,234 patients were transported by the primary aeromedical company; 153 patients were transported by ground and 25 patients were transported by other aeromedical services because of weather or unavailability of aircraft. RESULTS: There were no differences at 30 days for survivors in disability, health status, or health care utilization. Nineteen percent of helicopter-transported patients died compared with 15% of those transported by ground (p=0.21). CONCLUSION: The patients transported by helicopter did not have improved outcomes compared with patients transported by ground. These data argue against a large advantage of helicopters for interfacility transport. A randomized trial is needed to address these issues conclusively.

Sequential alterations in gut mucosal amino acid and glucose transport after 70% small bowel resection.

BACKGROUND: Studies in animals with short bowel syndrome (SBS) suggest that up-regulation of nutrient transporter activity occurs as an adaptive response to the loss of absorptive area. It is unclear, however, whether nutrient transport is altered at the cell membrane in SBS. The purpose of this study is to clarify amino acid and glucose transport in small intestinal luminal mucosa after 70% small bowel resection in rabbits. METHODS: New Zealand white rabbits underwent 70% jejunoileal resection (n = 27) or a sham operation (n = 19). Brush border membrane vesicles were prepared from small intestinal mucosa at 1 week, 1 month, and 3 months by magnesium aggregation-differential centrifugation. Transport of L-glutamine, L-alanine, L-leucine, L-arginine, and D-glucose was assayed by a rapid mixing-filtration technique. RESULTS: We observed no difference in uptake of all amino acids and glucose at 1 week. The uptake of amino acids and glucose was decreased by 20% to 80% in animals with SBS at 1 month. By 3 months all uptake values except that of glucose returned to normal. Kinetic studies of the system B transporter for glutamine indicate that the decrease in uptake at 1 month was caused by a reduction in the Vmax (1575 +/- 146 versus 2366 +/- 235, p < 0.05) consistent with a decrease in the number of functional carriers on the brush border membrane. CONCLUSIONS: In addition to the anatomic loss of absorptive area after massive bowel resection, alterations in enterocyte transport function may be responsible for malabsorption in patients with SBS.

Adrenocortical neoplasm disguised as a post-traumatic perinephric hematoma.

Trauma and cancer are entities that are encountered frequently by surgeons and occasionally may exist simultaneously in certain patients. Illustrated here is the case of a man with a perinephric mass, discovered during evaluation for blunt abdominal trauma, which was originally thought to be a perinephric hematoma and later proved to be an adrenocortical carcinoma.

Improved detection of cardiac contusion with cardiac troponin I.

Detecting cardiac injury in patients with chest trauma is difficult because the level of the MB isoenzyme of creatine kinase (MBCK) can be elevated from skeletal muscle injury alone. However, the level of cardiac troponin I (cTnl) is not elevated by skeletal muscle injury. To determine whether its measurement would improve the ability to detect cardiac injury in patients with blunt chest trauma, 44 patients were studied. Serial echocardiograms and serial blood samples were obtained. Six patients had evidence of cardiac injury by echocardiography; all had elevations of MBCK and cTnl. One patient had elevations of both MBCK and cTnl with only a pericardial effusion. Twenty-six of the 37 patients without contusion had elevations of MBCK; none had elevations of cTnl. The ratio of MBCK to total creatine kinase improved specificity at the expense of sensitivity. Measurement of cTnl accurately detects cardiac injury in patients with blunt chest trauma and should facilitate the diagnosis and management of such patients.

Acute repair of aorta-innominate vein fistulas.

Penetrating wounds of the central vasculature are highly lethal. Ten cases of aorta-left innominate vein fistulas have been reported in the past, but most have presented late after injury. We report three successfully managed cases that had a short interval between injury and repair, and where we used cardiopulmonary bypass with total circulatory arrest. Preoperative arteriography facilitated planning the operative approach. The ready availability of complete radiologic and surgical resources at a trauma center were responsible for the successful outcome of these highly lethal central vascular injuries.

Hypertonic sodium resuscitation is associated with renal failure and death.

OBJECTIVE: The use of hypertonic sodium solutions (HSS) and lactated Ringer's (LR) solution in the resuscitation of patients with major burns was compared. SUMMARY BACKGROUND DATA: Hypertonic sodium solutions have been recommended for burn resuscitation to reduce the large total volumes required with isotonic LR solution and their attendant complications. METHODS: To evaluate the efficacy of this therapy in our adult burn center, we resuscitated 65 consecutive patients with HSS (290 mEq/L Na) between July 1991 and June 1993 and compared them with 109 burn patients resuscitated with LR (130 mEq/L Na) between July 1986 and June 1988 (LR-1). A subsequent 39 patients were resuscitated with LR between September 1993 and August 1994 (LR-2). RESULTS: Patients receiving hypertonic sodium solutions versus LR-1 were similar with respect to age (46.0 vs. 43.6 years), total burn size (39.2% vs. 39.9%), incidence of inhalation injury (41.5% vs. 47.7%), and predicted mortality (34.6% vs. 30.2%). Total resuscitation volumes during the first 24 hours were lower among patients treated with HSS than those in the LR-1 group (3.9 +/- 0.3 vs. 5.3 +/- 0.2 mL/kg/% body surface area [BSA], p < 0.05). After 48 hours, however, cumulative fluid loads were similar (6.6 +/- 0.6 vs. 7.5 +/- 0.3 mL/kg/%BSA), and total sodium load was greater with the HSS group (1.3 +/- 0.1 vs. 0.9 +/- 0.1 mEq/kg/%BSA, p < 0.002). During the first 3 days after burn, serum sodium concentrations were moderately elevated in the HSS patients (153 +/- 2 vs. 135 +/- 1 mEq/L, p < 0.001). Patients resuscitated with HSS had a fourfold increase in renal failure (40.0 vs. 10.1%, p < 0.001) and twice the mortality of LR-1 patients (53.8 vs. 26.6%, p < 0.001). In patients resuscitated with HSS, renal failure was an independent risk factor (p < 0.001, by logistic regression). Analysis of these results prompted a return to LR resuscitation (LR-2). Age (41.6 +/- 2.9 years), burn size (37.8 +/- 3.9 %BSA), and incidence of inhalation injury (51.3%) were similar to the earlier groups. Total sodium load was less among LR-2 patients than the HSS group (0.7 +/- 0.1 mEq/kg/%BSA, p < 0.01), but similar to the LR-1 patients. Renal failure developed in only 15.4%, and 33.3% died, similar to the LR-1 group and significantly lower than patients treated with HSS (p < 0.001 and p < 0.05, respectively). CONCLUSION: Hypertonic sodium solution resuscitation of burn patients did not reduce the total resuscitation volume required. Furthermore, it was associated with an increased incidence of renal failure and death. The use of HSS for burn resuscitation may be ill advised.

Starvation induces differential small bowel luminal amino acid transport.

BACKGROUND: The importance of small intestinal mucosa functions has been emphasized in recent years because gut metabolism becomes better defined. One of the major activities of the enterocyte is amino acid transport, which is important not only for the organism but also for the integrity of the mucosa. Bowel rest during the postoperative period is marked by decreased calorie and protein intake with atrophy of the brush border mucosa. We sought to determine whether active amino acid transport is altered during 72 hours of fasting. METHODS: New Zealand white rabbits were fed (control) or fasted for 72 hours. Brush border membrane vesicles were prepared from scraped jejunal mucosa, and their purity was assessed by marker enzyme enrichment (17- to 25-fold). Transport of tritiated glutamine, arginine, alanine, methylamino-isobutyric acid (MeAIB), and leucine into brush border membrane vesicles was measured by rapid mixing filtration. RESULTS: Fasted animals lost on average 138 +/- 51 gm of body weight. Glutamine and arginine transport were decreased in rabbits fasted for 72 hours compared with controls; alanine, MeAIB, and leucine transport were maintained. The decrease in Glutamine transport was due to a decrease in Vmax (545 +/- 22 versus 836 +/- 93 pmol/mg protein/10 sec; p < 0.05), consistent with a decrease in the number of functional transporter proteins. Km values were similar in both groups (644 +/- 25 versus 624 +/- 18 mumol/L), indicating no change in carrier affinity. CONCLUSION: Differential changes occur in brush border amino acid transport during a 3-day period of bowel rest. The apparent gut nutritive transporters for Glutamine and arginine are decreased, although the gluconeogenic transporters for alanine, MeAIB, and leucine are maintained. These adaptive changes may help explain the difficulties seen in postoperative and critically ill patients on prolonged bowel rest.

Critical care for the elderly patient.

Elderly individuals will continue to make up a major portion of patients requiring critical care. Age and chronic disease-related factors blunt the reserves with which the elderly can meet the demands of critical surgical illness. The clinician must remain vigilant to subtle changes in the patient's course which may indicate a developing complication and must pay attention to all the details of comprehensive critical care management. With careful attention and timely physiologic support, the elderly patient has as good a chance of surviving as a similarly ill younger patient, although his or her course may be more prolonged. The priorities are the same. Thus, the primary disease must be addressed: necrotic tissue débrided, pus drained, wounds closed, fractures set. Cardiopulmonary performance (oxygen delivery) must be maintained sufficiently to meet the heightened oxygen needs associated with critical illness. This may require invasive hemodynamic monitoring and pharmacologic support. Gas exchange in the lungs must be maintained without compromising cardiovascular function or exhausting the patient. Patients should be kept warm, pain free, and calm. Intravascular volume and the composition of the extracellular fluid must be maintained. Nutritional support should be provided early in amounts sufficient to meet the patient's basal nutritional requirements and increased needs associated with the critical illness. If at all possible, some or all of this nutritional support should be provided via the gastrointestinal tract. The use of specialized nutrients or of agents designed to minimize the catabolism of critical illness or to enhance anabolism is an area of active investigation. The indications for these therapeutic strategies in the elderly should become clearer in the years ahead.

Computer-based videotape analysis of trauma resuscitations for quality assurance and clinical research.

PURPOSE: To automate time (and motion) studies of major trauma resuscitations. TECHNIQUES: We modified an existing time-motion study technique based on time-encoded videotaping for medical imaging workstation human factors analysis. Videotapes were recorded of the trauma room during normal clinical activity using an unobtrusive mounted camera. The videotapes are displayed through a customized interface using a Macintosh-based display system. Within this platform, the time-motion study module allows flexible task definition, multiple concordant task assignment, and various summary result presentations. We established an expert panel of two traumatologists, two emergency radiologists, and two time-motion study experts. The expert panel prospectively and uniquely defined important recognizable procedural and cognitive tasks and personnel (MD, RN, EMT, RT, etc.) involved in trauma resuscitation based on pilot recordings and collective experience. These task functions were used to define a menu in the time-motion analysis software. During retrospective videotape review, the beginning and ending times of each task performed were recorded by electronically highlighting each defined individual and task. The summary results can be displayed in list, tabular, or graphic form by individuals, personnel classifications, or tasks.

Early hormonal changes affect the catabolic response to trauma.

OBJECTIVE: The authors sought to determine how temporary insulin suppression might alter the catabolic effects of cortisol, glucagon, and epinephrine. SUMMARY BACKGROUND DATA: The metabolic responses to injury include hypermetabolism, accelerated net skeletal muscle protein breakdown, glucose intolerance, and insulin resistance. These alterations are associated with increased stress hormone concentrations. Insulin elaboration is usually suppressed immediately after an injury but is abundant later during convalescence. An infusion of hydrocortisone, glucagon, and epinephrine increases both stress hormone concentrations and insulin levels. It induces many of the metabolic alterations seen in critically ill patients, but it does not affect net muscle breakdown. METHODS: Seven healthy adults received a stress hormone infusion for 3 days in two separate studies. During one study they, also received an infusion of the somatostatin analogue, octreotide (0.005 micrograms/kg/min), to suppress insulin elaboration for the first 24 hours. During the other study (control), insulin was permitted to rise unchecked. RESULTS: Stress hormone concentrations, hypermetabolism (+/- 20% above basal), and leukocytosis were similar during both study periods. When insulin elaboration was temporarily suppressed, whole-body nitrogen loss was increased during the first 48 hours, and the efflux of amino acids from the forearm after 72 hours of infusion was 60% greater than the control level. CONCLUSIONS: Temporary insulin suppression during physiologic increases in stress hormone concentrations amplified whole-body nitrogen loss and led to the development of accelerated net skeletal muscle protein breakdown. Early hormonal changes after an injury may affect the development of later catabolic responses.

Benefits and limitations of burn wound excision.

This review is intended to provide a balanced view of the role of surgical burn wound excision and closure within the larger context of the total care and rehabilitation of patients with burn injury. The historical background leading to present practice is outlined. The salient technical and logistical problems associated with the performance of wound excision are discussed, with emphasis on the necessity for expeditiously completing these procedures which are associated with major blood loss. A realistic analysis of the results of excisional therapy in patients with burns of varying severity is presented. Benefits attributable to the surgical phase of therapy become progressively more difficult to identify as the size of deep burns increases beyond 20% of total body surface area.

Alternative approaches to abdominal wound closure in severely injured patients with massive visceral edema.

Excessive tension in an abdominal incision line may lead to fascial necrosis and wound sepsis. We utilized two alternative approaches to wound closure in 13 patients with severe abdominal trauma (2 blunt, 11 penetrating) whose midline incision could not be closed primarily without excessive tension at the initial operation because of massive visceral edema. In five patients synthetic mesh was used to bridge the fascial defect. Four patients survived the early postoperative period but had large open midline wounds that required one or more delayed procedures to close the wound or cover the visceral mass with skin graft. Two patients currently have large abdominal wall hernias. In the other eight patients the skin was reapproximated over the visceral mass utilizing towel clips at the initial operation. Six patients survived to be reexplored within 48-96 hours. Acute hemorrhage had stopped, the edema of the bowel and retroperitoneum had largely resolved, and the fascia could be closed primarily without excessive tension. All wounds went on to heal satisfactorily. When massive edema makes fascial closure at the initial operation difficult or impossible, closure of the skin over the visceral mass promotes resolution of the edema and often allows satisfactory primary closure within 48-96 hours. Synthetic mesh should be reserved for cases of abdominal wall tissue loss or dehiscence associated with wound sepsis.

Posttraumatic skeletal muscle proteolysis: the role of the hormonal environment.

To investigate the role of hormones as mediators of net skeletal muscle proteolysis following injury, healthy normal male volunteers received a continuous 76-hour infusion of the 3 "stress" hormones: hydrocortisone, glucagon, and epinephrine. As a control, each subject received a saline infusion during another 4-day period. Ten paired studies were conducted. Diets were constant and matched on both occasions. Triple hormone infusion achieved hormone concentrations similar to those seen following mild-moderate injury. After 72 hours of infusion, skeletal muscle intracellular glutamine concentrations were lower in the hormone studies than in the control group (N = 4). Free amino acid concentrations in arterial whole blood and forearm amino acid efflux were little affected by hormonal infusion. Thus, alteration of the hormonal environment by the triple hormone infusion was not a sufficient stimulus to induce all of the changes in skeletal muscle proteolysis observed in critical illness. Since studies utilizing neurohormonal blockade have shown diminished net muscle proteolysis, the stress hormones appear to be necessary but not sufficient for the protein catabolic response to injury.