Palmer Q. Bessey

Mechanisms of insulin resistance following injury.

To assess the mechanisms of insulin resistance following injury, we examined the relationship between insulin levels and glucose disposal in nine nonseptic, multiple trauma patients (average age 32 years, Injury Severity Score 22) five to 13 days postinjury. Fourteen age-matched normals served as controls. Using a modification of the euglycemic insulin clamp technique, insulin was infused in 35 two-hour studies using at least one of four infusion rates (0.5, 1.0, 2.0 or 5.0 mU/kg min). Basal glucose levels were maintained by a variable infusion of 20% dextrose using bedside glucose monitoring and a servo-control algorithm. The amount of glucose infused reflected glucose disposal (M, mg/kg.min). Tracer doses of (6,6,2D2) glucose were administered in selected subjects to determine endogenous glucose production. At plasma insulin concentrations less than 100 μU/ml, responses in both groups were similar. However, maximal glucose disposal rates were significantly less in the patients than in the controls (9.17 ± 0.87 mg/kg.min vs. 14.3 ± 0.78, mean SEM, p <0.01). Insulin clearance rates in the patients were almost twice that seen in controls. To further characterize this decrease in insulin responsiveness, we studied six additional patients and 12 controls following the acute elevation of glucose 125 mg/dl above basal (hyperglycemic glucose clamp). In spite of exaggerated endogenous insulin production in the patients (80–200 μU/ml vs. 30–70 in controls), M was significantly lower (6.23 ± 0.59 vs. 9.46 ± 0.79, p < 0.02). In conclusion, this study demonstrated that (1) the maximal rate of glucose disposal is reduced in trauma patients; (2) the metabolic clearance rate of insulin in the injured patients is almost twice normal and; (3) insulin resistance following injury appears to occur in peripheral tissues, probably skeletal muscle, and is consistent with a postreceptor defect.

Hypertonic sodium resuscitation is associated with renal failure and death.

Objective The use of hypertonic sodium solutions (HSS) and lactated Ringers (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.

National Burn Repository 2005: a ten-year review.

In the early 1990s, the American Burn Association (ABA) started its first burn registry development initiatives. The impetus for the registry development software originated from several directions, including the following: (1) the recognition that national registries were widespread and of proven benefit; (2) growing demands from accrediting institutions, payers, and patient advocacy groups for objective and verifiable data regarding patient costs, treatments, and outcomes; and (3) the shift toward “evidence-based” medicine and the ongoing analysis of treatment effectiveness. The ABA has issued three calls for burn registry data for its National Burn Repository (NBR): 1994, 2002, and 2005. In 1994, 28 burn centers contributed data for more than 6,400 patients treated from 1991 to 1993. The ABA announced its second call for data in 2001 and distributed the published results of more than 54,000 acute burn admissions treated from 1974 to 2002 at the Association’s 2002 Annual Meeting. The third ABA call for data was issued in the Fall of 2005. The results are detailed in this report, which provides a summary of more than a quarter million acute burn admissions from 1995 to 2005, representing 70 hospitals from 30 states plus the District of Columbia. Statistics are presented in chart and table format to illustrate such key factors as patient age, burn size group, types of injuries, mortality rates, and average hospital charges by etiology and length of hospital stay. The data presented herein should help stimulate quality improvement programs in burn care, as burn centers compare their performance with the national data and as research is expanded using the NBR. The NBR will be published annually and, with continued refinements to the registry software, should become of increasing importance to clinicians, payers, researchers, and the public.

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.

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.

National burn repository 2006: A ten-year review

This article presents findings from the National Burn Repository (NBR) 2006 Annual Report. Data reported herein cover a 10-year period from January 1, 1996, through June 30, 2006. This year’s report includes the first comparative presentations of data over time to show what appear to be trends in the dataset. The purpose of this report is to share information about the current state of care for burned patients in the United States. Some of the implications include epidemiology, burn-prevention efforts, research, education, acute care and quality improvement in burn programs, resource allocation, and reimbursement issues.

Suppression of natural killer-cell function in humans following thermal and traumatic injury.

Depressed cell-mediated and humoral immune functions have been reported to occur following severe thermal and traumatic injury. In this study we have questioned whether another immune function, natural killing (NK), is also disturbed in these injured patients. Twenty-two thermally injured patients with burns ranging from 5 to 75% of the total body surface area and 15 traumatically injured patients with injury severity scores ranging from 9 to 56 were followed postinjury and compared to 29 age-matched controls. NK activity was measured as the percentage cytotoxicity in chromium-51 release assays with K562 target cells. The more severely burned patients had significantly depressed NK activity for the 40-day period following injury that remained reduced for the duration of the study. Patients with lesser burns had reduced NK-cell function for the initial 10-day period postburn that returned slowly to the normal range. Traumatically injured patients had depressed NK-cell function during the 3- to 6-day period postinjury. The percentage of cells bearing phenotypic markers for the groups in which Nk cells are found was either normal or elevated in these patients. A correlation was found between NK activity and interleukin 2 generation by mononuclear cells from these patients. In order to investigate the mechanism of NK suppression in these patients, NK-cell function was studied following the infusion of cortisol, epinephrine, and glucagon into volunteer subjects in amounts known to reproduce serum levels seen following injury of moderate severity. NK-cell function was reduced an average of 66% following infusion, suggesting that the inhibition of NK-cell function seen in patients may be mediated by the stress response to injury.

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.

Enhancement of protein synthesis efficiency in parenterally fed trauma victims by adjuvant recombinant human growth hormone.

In the early catabolic phase of severe injury, conventional nutritional support is inadequate to reverse negative nitrogen balance and an anabolic stimulus may be beneficial. The utilization efficiency of body energy sources after injury could be improved by adjuvant recombinant human growth hormone (rhGH) therapy. We measured the protein kinetic response to exogenous rhGH in trauma patients fed parenterally (TPN). Severely injured (mean ISS, 31 +/- 2), highly catabolic (mean nitrogen loss, 19 +/- 2 g/day), and hypermetabolic (mean BEE/REE, 1.41 +/- 0.05), adult (mean age, 46 +/- 5 years), multiple trauma victims (n = 20, 17 men/3 women) were investigated. Rates of whole-body protein kinetics (turnover [WBPT], synthesis [WBPS], breakdown [WBPB], and protein synthesis efficiency [PSE]--the fraction of nitrogen turnover utilized for protein synthesis) were measured using a primed-constant infusion of 18N glycine 48 to 60 hours after injury when the patients were receiving only maintenance fluids without calories or nitrogen. The patients were then fed glucose-based TPN (1.1 x REE; 250 mg N/kg/day) and randomized to receive or not to receive rhGH. Group H (n = 10) received daily rhGH (0.15 mg/kg/day, Somatropin, Genentech, Inc.) intramuscularly at 8 am and group C (n = 10) received only the vehicle of infusion. Protein kinetic measurements were repeated at the end of 7 days.(ABSTRACT TRUNCATED AT 250 WORDS)

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.