Cimetidine kinetics during resuscitation from burn shock.

Severely burned patients suffer from rapidly changing metabolic and hemodynamic abnormalities that could alter drug kinetics. The kinetics of cimetidine, commonly used in the prophylaxis of acute stress erosions, were studied during fluid resuscitation of 11 patients with mean burn sizes of 45% total body surface area. Six patients were studied after the completion of fluid resuscitation. Total clearance, steady-state volume of distribution, and cimetidine t1/2 did not change between the early period after burn and after fluid resuscitation, but before the completion of fluid resuscitation patients had lower renal and greater nonrenal cimetidine clearance than after resuscitation. The increase in nonrenal cimetidine clearance resulted in decreased urinary recovery of unchanged drug, 50.7 +/- 14% during fluid resuscitation and 81.0% +/- 6% after resuscitation.

Prosthetic valve endocarditis. The case for prompt valve replacement.

Treatment of patients with prosthetic valve endocarditis with existing guidelines has failed to reduce the over-all mortality rate to below 50 per cent. However, subgroups with high or lower risk of death can be delineated on the basis of risk factors such as early onset following surgery, high-risk causative organisms, cardiodynamic failure, and septic emboli. High-risk patients comprise more than 70 per cent of those with prosthetic valve endocarditis in recent series. Analysis of previously reported series indicates that the mortality rate for high-risk patients with late onset of prosthetic valve endocarditis treated by valve replacement was less than that of patients receiving only medical therapy. We have treated 6 consecutive patients with prosthetic valve endocarditis (3 early onset, 3 late onset) by valve replacement before completion of a course of antibiotics. All patients survived surgery but one patient died after 4 1/2 months of noninfectious causes. Prompt valve replacement is technically feasible and should become the standard therapy for patients with prosthetic valve endocarditis who do not fall into the lower risk group.

The continuing challenge of burn care in the elderly.

Recent improvements in survival have stimulated interest in the care of elderly patients with burn injuries. We reviewed 278 patients aged 45 years and older treated during a 10-year period. The survival rate was 80% overall and 67% for patients over 75 years of age. Mortality rates correlated with patient age, burn size, presence of inhalation injury, number of complications of care, and fluid resuscitation requirements, but not with the number of preexisting medical problems. Burn wound excision and skin grafting were performed frequently and were well tolerated. During this period, hospital charges increased fourfold and were twice as great in nonsurvivors. Reimbursements based on diagnosis-related groups during the last 3 years of the review (75 patients) resulted in a total deficit of $1.2 million. Aggressive care for most elderly patients with burn injuries appears justified by the improved outcomes demonstrated. This has increased the difficulty of decisions regarding patient salvability and the allotment of resources. Elderly patients with burn injuries illustrate many contemporary dilemmas in patient care in this era of cost consciousness.

The effect of exchange therapy on postburn lymphocyte suppression.

Circulating mediators have been implicated in the pathophysiology of postburn immunologic depression, suggesting the restorative potential of exchange therapy. Previous reports have stressed the immunosuppressive effects of massive transfusions and major surgical procedures. The effect of plasma exchange (PLA/EX) and surgical excision and grafting (E/G) procedures on postburn lymphocyte function was evaluated retrospectively in one-way mixed lymphocyte reaction assays. Twenty one adult patients with a mean total body surface area (TBSA) burn of 52.6% underwent a total of 54 PLA/EX procedures without complications. The mean volume of plasma exchanged was 5079 ml. PLA/EX was performed at a mean time of 10.4 days after burn injury. Thirty adult patients with a mean TBSA burn of 42.8% underwent a total of 78 E/G procedures. The mean graft size was 2373 cm2 per E/G procedure or 7.25% TBSA. The mean transfusion requirement per E/G was 3355 ml. The initial E/G occurred at a mean of 7.5 days after burn injury. PLA/EX decreased suppression of normal lymphocyte blastogenesis by burn serum from 62.7% to 28.3% (p less than 0.001). The mean duration of improvement in lymphocyte function was 4.8 days. Similarly, the mean suppression by burn serum drawn pre-E/G was 42.2%, while serum suppressive activity post-E/G was 29.1% (p less than 0.05). The mean duration of mixed lymphocyte reaction improvement was 5.0 days. Both PLA/EX and E/G procedures have a significant beneficial effect in restoring lymphocyte function in burn patients.

Measurement of intramuscular pressure in the management of massive venous occlusion.

While controversy continues over the exact pathophysiology of and optimal therapy for phlegmasia cerulea dolens, increasing evidence favors the role of elevated interstitial pressure in the generation of extremity ischemia. We report the use of intramuscular pressure measurements in the assessment of a patient suffering massive venous occlusion of one leg. Significant elevations in pressure were found in association with symptomatic ischemia. Successful thrombectomy restored blood flow, relieved symptoms, and produced an immediate decrease in intramuscular pressure. In this disorder, measurement of compartment pressures can be useful in assessing the severity of venous insufficiency and in monitoring the response to therapy.

The effect of plasma exchange on lymphocyte suppression after burn.

Circulating mediators have been implicated in the pathophysiology of immunodepression after burn injury, suggesting the beneficial effect of plasma exchange in immunorestoration. In this study, 19 adult patients with a mean burn size of 52.2% of total body surface area and mean age of 33.4 years underwent 51 plasma exchange procedures in five different clinical settings, without complication. The suppressive effect of burn serum was assayed in mixed lymphocyte cultures. The mean (+/- SEM) suppression by burn serum drawn prior to plasma exchange was 61.9% +/- 3.6%, while that following plasma exchange was 27.3% +/- 2.7%. The lymphocyte response decrease 55.1% +/- 4.4% in suppressive activity. The mean duration of improvement in lymphocyte function was 4.8 days. Plasma exchange has a significant beneficial effect in restoring lymphocyte immunocompetence in burned patients in a number of clinical settings.

The 1942 fire at Boston's Cocoanut Grove nightclub.

The year 1992 marked the 50th anniversary of one of the worst civilian disasters in American history. On November 28, 1942, fire destroyed Boston's Cocoanut Grove nightclub, killing 491 people and sending hundreds more to area hospitals. The disaster came at a unique time in the history of burn care and resulted in a number of important advances in burn treatment, including the first comprehensive descriptions of inhalation injury, improvements in topical treatment of burn wounds, resuscitation of shock, use of antibiotics, and understanding of the metabolic response to injury. In addition, the fire stimulated organization of burn care facilities, public safety legislation, and burn prevention. The history of the fire is reviewed, emphasizing its role in stimulating advances that formed some of the foundations of modern burn treatment.

Intramuscular pressure in the burned arm: measurement and response to escharotomy.

Using a wick catheter technique, sequential measurements of intramuscular pressure were obtained in 31 burned arms in 18 patients. Abnormally high pressures were recorded in 90 percent of extremities and exceeded the potentially harmful level of 30 mm Hg in 42 percent. Correlation of intramuscular pressure with signs and symptoms of extremity compression, including Doppler pulses, was poor. Intramuscular pressure elevation appeared to parallel edema formation beneath the burn wound. A high incidence of pressure measurements in excess of 30 mm Hg was found in patients who had 30 percent or greater total body surface area injury (67 percent), 10 percent or greater full-thickness burns (75 percent), and extremities with circumferential involvement (57 percent). In every case echarotomy produced a dramatic decrease in intramuscular pressure, while a randomized group of extremities that were not decompressed developed sustained pressures as high as 64 mm Hg despite the presence of intact Doppler pulses. Extremities treated in this manner appeared slower in resolving edema and regaining motion and strength. Measurement of intramuscular pressure beneath the burn eschar is recommended in evaluating all patients at risk from extremity burns.

Management of tar and asphalt injuries.

Tar and asphalt burns are unique injuries because the chemical is difficult to remove without inflicting further tissue injury. Since 1978, 42 patients have been treated for hot tar or asphalt injuries, 30 of whom required hospitalization. Inpatients were all male with a mean age of 27.2 years and a mean burn size of 9.3 percent total body surface area (mean full-thickness injury 5.3 percent total body surface area). Burns of critical areas were present in 63.3 percent of the inpatients. A petroleum-based, surface-active solvent was used to remove the tar or asphalt. This solvent proved nonirritating and removed tar much faster than other agents. Early excisional therapy was performed in 63.4 percent of the patients, 80 percent of whom returned to work within 6 weeks of injury. Principles of management include rapid cooling of tar or asphalt to solidify the inciting agent and dissipate heat; removal with a new, non-toxic solvent; early excision and grafting of appropriate injuries; and an aggressive, early back-to-work philosophy.

Effect of inhalation injury on fluid resuscitation requirements after thermal injury.

The presence of inhalation injury has been reported to increase fluid requirements for resuscitation from burn shock after thermal injury. To evaluate the effect of inhalation injury on the magnitude of burn-induced shock, the characteristics of resuscitation of 171 patients with burns covering at least 25 percent of the total body surface area were reviewed. When inhalation injury was suspected, confirmation by xenon-133 scanning, bronchoscopy, or both was obtained. Initial fluid resuscitation was calculated according to the Parkland formula, and titration was initiated to maintain a urine output of 30 to 50 ml/hour. Fifty-one patients had inhalation injuries. Patients with inhalation injuries had a mean fluid requirement of 5.76 ml/kg per percentage of total body surface area burned and a mean sodium requirement of 0.94 mEq/kg per percentage of total body surface area burned to achieve successful resuscitation, compared with a fluid requirement of 3.98 ml/kg per percentage of total body surface area burned and a sodium requirement of 0.68 mEq/kg per percentage of total body surface area burned for the group without inhalation injury (p less than 0.05). These data confirm and quantitate that inhalation injury accompanying thermal trauma increases the magnitude of total body injury and requires increased volumes of fluid and sodium to achieve resuscitation from early burn shock.

Etiology and consequences of respiratory failure in thermally injured patients.

Inhalation injury predisposes burn patients to pneumonia, respiratory failure, and death, but the incidence and consequences of respiratory failure in the absence of inhalation injury are not well known. In a review of 529 burn patients admitted over a 4-year period, patients with inhalation injury had a 73% incidence of respiratory failure (hypoxemia, multiple pulmonary infections, or prolonged ventilator support) and a 20% incidence of adult respiratory distress syndrome (ARDS). In patients without inhalation injury, respiratory failure developed in 5% of patients and ARDS in 2% (both p < 0.001). Patients with respiratory failure display a high incidence of multiple organ failure and mortality (27% to 50%), regardless of the presence of inhalation injury. All patients who died had multiple organ failure. This review demonstrates that respiratory failure, regardless of its cause, frequently leads to multiple organ failure and death. Inhalation injury, in the absence of respiratory failure, does not appear to contribute to mortality.

Burn center management of necrotizing soft-tissue surgical infections in unburned patients.

BACKGROUND: Patients with necrotizing soft-tissue infections present great challenges in management from initial presentation through definitive care. Because burn centers concentrate expertise in critical care, wound management, and rehabilitation, we examined the effectiveness of burn center care for patients with necrotizing infections. METHODS: We reviewed our burn center's experience with all patients admitted from 1990 through 1999 with a primary diagnosis of necrotizing fasciitis (NF) or Fournier's gangrene (FG). RESULTS: Fifty-seven patients were identified, 18 with FG and 39 with NF. Patients had a high incidence of preexisting medical problems, including diabetes (37%), obesity defined as greater than 20% above ideal body weight (33%), and hypertension (33%). Seven of 57 (12%) patients died. Patients required a mean of 4.1 operative procedures (range 1 to 15) for definitive wound closure. The mean length of stay (survivors only) was 28.5 days, (range 3 to 70). Although costs increased throughout this period, a formal program of cost-containment resulted in no increase in actual charges per day, from a mean of $4,735 in 1991 to $5,202 in 1999. CONCLUSIONS: Burn centers can provide successful and cost-effective acute care, definitive wound closure, and rehabilitation for patients with NF and FG.

Necrotizing group A streptococcal infections associated with streptococcal toxic shock syndrome.

BACKGROUND: Group A streptococci (GAS) cause a variety of life-threatening infectious complications, including necrotizing fasciitis (NF), purpura fulminans (PF), and streptococcal toxic shock syndrome (strepTSS), in which bacteremia is associated with shock and organ failure. METHODS: We reviewed our experience in the management of patients with necrotizing GAS infections from 1991 to 1995. RESULTS: Eight adult patients (6 NF, 2 PF) were identified. Patients presented with fever, leukocytosis, and severe pain, and rapidly developed shock and organ dysfunction. The diagnosis of strepTSS was confirmed in 6 cases. A total of 54 surgical procedures were required, including widespread debridements and amputations. Two patients died (25%). CONCLUSIONS: Recognition of the need for aggressive diagnosis and surgical treatment of this most rapidly progressive surgical infection is necessary for successful management.

Increased survival after major thermal injury. A nine year review.

This study has reviewed the results of burn care in a burn center between 1978 and 1986. The total population included 1,458 patients. Mean burn size was 19 percent total body surface area, mean patient age was 24.4 years, and overall survival rate was 92 percent. We separately analyzed patients with burns of 30 percent total body surface area or greater during both halves of the study with respect to survival and length of hospital stay. Before 1982, patient survival was 59 percent and mean length of hospital stay was 28.1 days. Since that, the survival rate increased to 77 percent and mean length of hospital stay increased to 35.2 days. The early burn mortality rate remained nearly constant during the period of study (17 percent during the first half of the study and 16 percent during the second half), but the late mortality rate decreased significantly during the second half of the study (24 percent versus 8 percent, p less than 0.01). These data demonstrate increased survival rates after major thermal injury due to improvements in prevention and treatment of sepsis and other late complications of thermal injury.

Fluid resuscitation in thermally injured children.

The fluid resuscitation requirements and mortality from thermal injury were reviewed in 177 children admitted to the Intermountain Burn Center over a 7 year period. Mean burn size was 27 percent of the total body surface area, whereas the mean full-thickness burn size was 13 percent of total body surface area. Twelve percent of children had associated inhalation injuries. The mean amount of fluid received during burn shock resuscitation was 5.8 +/- 0.25 ml/kg per percentage of total body surface area burned and the mean amount of sodium, 1.06 +/- 0.04 mEq/kg per percentage of total body surface area burned. There was no morbidity due to fluid overload. The presence of inhalation injury did not increase fluid or sodium requirements, but did increase mortality (29 percent versus 7 percent, p less than 0.05). The resuscitative mortality rate for all pediatric patients was 7 percent, the in-hospital mortality rate was 15 percent, and the 50 percent mortality burn correlate for these patients was 64 percent of the total body surface area. Data on children with burns were compared with an unselected, concurrent group of adult burn patients using an analysis of covariance. Fluid and sodium requirements were significantly higher for children, but there was no difference in the length of resuscitation or mortality rate. We conclude that children require much more fluid for resuscitation from burn shock than adults with similar burns. Appropriately aggressive fluid therapy for acute thermal injury in children is essential to achieve an acceptable survival rate in these patients.

Is immediate chest radiograph necessary after central venous catheter placement in a surgical intensive care unit?

BACKGROUND: Current standard of care dictates that central venous catheter (CVC) insertion should be followed by an immediate chest radiograph to confirm appropriate position and rule out complications. We hypothesized that a subset of monitored intensive care unit patients exists that is at low risk for complications and might safely have radiographic evaluation of line placement deferred until the next scheduled radiograph. METHODS: Data regarding patient and procedural characteristics were obtained prospectively for 184 CVC placed between March 1, 1998, and June 30, 1999. Retrospective data regarding complications were obtained by chart review for an additional 174 CVC placed during the study period but for which data sheets were not completed. All procedures were followed by chest radiography. RESULTS: We documented a complication rate of 9% with the vast majority (25 of 31, 81%) of complications consisting of incorrect positioning. The number of needle passes was greater in the group suffering pneumothorax and arterial puncture than the uncomplicated group (5.6 versus 1.9, P = 0.008). "Straightforward" operator gestalt (P = 0.04) and number of needle passes <3 (P = 0.03) were factors correlating with the absence of complications. These factors had negative predictive values of 94% and 96%, respectively. CONCLUSION: Placement of CVC is safe in experienced hands. In monitored intensive care unit patients who undergo a "straightforward" procedure with <3 needle passes, chest radiograph can be safely deferred until the next scheduled examination.

Calculation of metabolic expenditure and substrate utilization from gas exchange measurements.

At least nine different equations have been published for calculating metabolic expenditure by indirect calorimetry. This study examined the differences between equations when they are used for the nutritional assessment in an intensive care unit (ICU). Oxygen consumption and carbon dioxide production were measured in 36 ICU patients and used to calculate metabolic expenditure with the nine equations. The equations produced differences in metabolic expenditure which averaged from 0.8-96 kcal/day. The largest difference produced by any two of the nine equations was 189 kcal/day. Although differences in original stoichiometric data have resulted in numerous different equations for the calculation of metabolic expenditure, these differences are not clinically important. It makes little difference which equation is used for nutritional assessment in an ICU.

Topical agents in burn and wound care.

With any open wound infection may occur. Many factors such as age and general health status may increase the likelihood of infection, but the size and depth of the wound are critical factors in determining the chronicity of any wound. Infection greatly adds to the morbidity associated with open wounds. An infected wound not only heals more slowly, there is also the risk of systemic infection and even death. Infected wounds also scar more severely and are associated with more prolonged rehabilitation. Topical therapeutic agents have been shown to be effective in the management of open skin wounds. These agents may assist less complicated healing and decrease the conversion of a partial-thickness injury to a full-thickness injury, and thereby reduce wound-related morbidity. Common topical agents with suggestions for application are discussed in this review.

Rehabilitation of burn patients with concomitant limb amputation: case reports.

Burn patients with associated limb amputations present demanding rehabilitation problems, many of which might be expected to lead to chronic difficulties. Therapeutic goals following limb amputation include oedema reduction, prevention of contracture (through positioning and range of motion), stump shaping, both pre- and post-prosthetic fitting strengthening exercises of the limb and trunk, and gait training. Some patients present problems that are associated with both the burn injury and the limb amputation that cause concern among the physical therapy staff. Some of these situations include intolerance of the stump to pressure or manipulation due to remaining open wounds or fragility of newly skin grafted areas on the residual limb or delayed gait or functional training due to wounds on other body surface areas. Delays in stump preparation or other treatment aims due to continued surgical procedures can be worrisome. A review of these patients indicates the possible difficulties that rehabilitation personnel may face when treating burn victims who required amputation. Effective rehabilitation of these patients can be achieved despite the noted concerns.

Differences in mortality from thermal injury between pediatric and adult patients.

Children differ from adults in their responses to thermal injury, as reflected by higher reported mortality rates for equivalent major injuries. The age at which children's survival rates equal those of young adults has not been well defined, and some investigators have recently claimed that pediatric and adult burn mortality do not differ. We evaluated age-related mortality among 1,443 consecutive patients without inhalation injury treated from 1978 to 1988, inclusively. The sample consisted of 595 children aged 12 years or less, 243 children aged 13 to 20 years, and 605 young adults aged 21 to 40 years who served as a comparison group of patients with the best predicted survival. We separately examined mortality in patients with burns exceeding 30% total body surface area. There were no significant differences in mortality between age groups for the study sample as a whole, but among patients with large burns, children aged 0 to 48 months had higher mortality than comparably injured adults (31% v 12%, P less than .05 by analysis of covariance). Improvements in survival were also demonstrated between the first and second halves of the study period for children aged 25 months to 8 years. These data indicate that children 48 months of age and younger do not tolerate large thermal injuries as well as adults. Improvements in pediatric burn survival are being achieved in most age groups.