In vivo time-resolved brain phosphorus nuclear magnetic resonance.

Methods used to obtain and quantify high-quality time-resolved dog brain phosphorus nuclear magnetic resonance (31P NMR) spectra are described. In eight animals the normoxic dog brain spectra showed 10% of total phosphorus in ATP, 14% in phosphocreatine (PCr), and 38% in brain phospholipids containing phosphodiesters. The chemical shift between PCr and inorganic phosphate, 5.09, corresponded to an intracellular brain pH of 7.2. During hypoxia, PCr declined to 0.5 +/- 0.3 (n = 8) of starting levels, prior to any changes in brain ATP. Simultaneous recording of the EEG was obtained in two animals. During hypoxia, progressive PCr depletion was associated with progressive slowing of the EEG, which was essentially silent before significant changes occurred in brain ATP. Finally, the brain 31P NMR spectrum and pH were measured at 90-s intervals, and the sequential changes that followed respiratory arrest were monitored in one dog until high-energy phosphate depletion was complete.

Tertiary trauma care in a rural state.

Trauma patients in rural areas usually have no access to regional trauma systems or designated trauma centers. Efforts to provide quality trauma care in small hospitals may seriously overextend local capabilities. The urban trauma center retains an important role in trauma care even when the initial care must be provided at the local level. Twenty-five trauma patients were transferred to University Hospital between 1985 and 1988 after definitive care was initiated in community hospitals. During the same time period, a total of 147 trauma patients were transferred to the trauma service. No information was available on the total incidence of trauma. Medical records were reviewed to determine the reasons for transfer. Major reasons included the need for further complex surgery, better critical care support, and inadequate blood banks. Trauma centers serving rural areas provide a valuable resource well beyond the initial 24 hours.

Delayed diagnosis of duodenal rupture.

BACKGROUND: Although duodenal rupture is usually diagnosed during the course of surgery for other injuries, a small portion of such injuries occur in isolation. In such cases, the significance of the clinical and diagnostic findings may not be appreciated for an extended period. The primary determinant of mortality in duodenal rupture is the presence of associated injuries, but delay in diagnosis is often a secondary factor. METHODS: A retrospective case review of 8 patients with isolated duodenal rupture that was diagnosed more than 24 hours following the injury. RESULTS: In 5 cases, physicians did not look for the occult injury. In 3, patients did not seek medical attention. Two patients were initially treated with primary duodenal repair and drainage with poor results. All patients were eventually treated with pyloric exclusion that resulted in no deaths and no duodenal fistulas. Three patients developed abscesses after pyloric exclusion. They were drained without difficulty. CONCLUSION: Pyloric exclusion appears to offer a satisfactory option for dealing with the inflammation and contamination that result from prolonged soilage by duodenal contents.

Adult respiratory distress syndrome.

Basic scientists and clinicians have written numerous articles on the diverse causes of adult respiratory distress syndrome (ARDS). There is no specific diagnostic test for ARDS; the condition is characterized by interstitial lung edema, reduction in lung compliance, alveolar and small airway closure, decrease in functional residual capacity, and persistent hypoxia with increasing amounts of pulmonary blood flow coursing through nonventilated or poorly ventilated alveoli. Recent studies have emphasized the roles of macrophages and polymorphonuclear neutrophils in lung defense and injury. Advances in understanding the pathophysiology of ARDS have produced little significant change in the clinical management of the syndrome. There is no specific treatment for ARDS. The cornerstone of therapy is the early recognition and elimination of initiating factors such as sepsis. ARDS is not a single disease process, but appears to represent a final common pathway for the manifestation of a variety of lung injuries. The goal of therapy is to eliminate the predisposing condition and support the patient. New modes of ventilatory and pharmacologic therapy are presented.

Atypical surgical infections.

The management of infections requiring surgical drainage or debridement is a significant component of surgical education and practice. Standard Gram's stain and culture techniques usually allow ready identification and adjunctive therapy of the offending organism; however, the surgical patient population is changing. More patients who require surgery are elderly, critically ill, have been exposed to broad-spectrum antibiotics, or are otherwise immunosuppressed. We identified 33 infections in this group of 32 patients. The majority of the etiologic agents were not identified using traditional microbiologic techniques, often leading to a delay in diagnosis. In this high-risk group of patients, we recommend histologic study of tissue with special stains such as methenamine silver. When the patient's condition warrants, frozen sections can be used. Optimal outcome requires early recognition of the specific etiologic agent.

Surgical complications of thermal injury.

Aggressive control of intragastric pH in the burn patient has essentially eliminated upper gastrointestinal bleeding. The recent spectrum of complications in the thermally injured patient has shifted. Vascular occlusion and missed associated injury were the most frequent early complications in this review. Those complications occurring late in the course were attributed to sepsis originating in the burn wound. The common diagnostic error was to blame the burn injury for the patient's signs and symptoms. A high index of suspicion of an occult process must be exercised when caring for the burn patient who has burn shock with a decreasing hematocrit value or a compartment syndrome that does not respond to escharotomy or fasciotomy or the septic patient with a clean burn wound.

Beneficial effects of a hypertonic solution for resuscitation in the presence of acute hemorrhage.

Crystalloid solutions such as Ringer's lactate have become the standard for initial volume replacement after hemorrhage. Although the relative merits of blood, colloid, and crystalloid have been extensively studied, little attention has been directed toward determining the optimal composition of the crystalloid solution. Based on the beneficial properties of hypertonic lactated saline solution in burn resuscitation, we have extended its use to acute hemorrhage. Using an awake canine model analogous to the clinical situation, we compared hypertonic lactated saline solution with Ringer's lactate solution for resuscitation in the presence of acute blood loss. The hypertonic lactated saline solution group required less fluid to restore and maintain cardiac output and blood pressure while maintaining better urine output. Although the Ringer's lactate solution group had increased shunt function indicative of pulmonary dysfunction, the shunt function in the hypertonic lactated saline solution group did not differ from that in the control group. Serum sodium and osmolality values were higher in the hypertonic lactated saline solution group, but at no time did they approach toxic levels.

Repetitive tissue biopsy by venipuncture: enzyme activities in isolated leukocyte populations.

Despite the rapidly expanding clinical use of leukocyte biochemistry, there is a limited amount of data available on normal human leukocytes. Some of the problems associated with the clinical use of leukocytes are discussed briefly. Enzyme activities of alkaline and acid phosphatase, lysozyme, and beta-galactosidase are presented. Results are reproducible between normals when expressed per mg of leukocyte deoxyribonucleic acid (DNA). Much higher lymphocyte activties of lysozyme and alkaline phosphatase are noted than previously reported with cytochemical or intact cell systems. It has been demonstrated that leukocytes cannot be considered chemically homogenous but should be separated and considered as individual cell types.

Retrospective evaluation of admission criteria for paediatric electrical injuries.

In the medical community, the practice of admitting all electrical burns for 24-48 h of observation, monitoring and laboratory evaluation is widespread. This retrospective review of paediatric electrical burns was conducted to determine which patients may safely be treated as outpatients. Retrospective analysis of all paediatric burns admitted between 1980 and 1991 identified 35 patients with electrical injuries. Patients were divided into two groups for analysis: those burned by exposure to household voltages (120-240 V; n = 26) and those exposed to high voltages, in excess of 1000 V (n = 9). The majority of household electrical injuries occurred secondary to contact with the household 120 V (21/26). Contact with an extremity accounted for the largest number of these injuries (18/26). The mouth was the second most frequent site of injury (7/26). Most of these patients (20/26) had < 1 per cent BSA burn. No patient in the household-voltage group had an arrythmia that required treatment, nor were there any identified examples of compartment syndrome or other vascular complications. Seven patients did require minimal skin grafting. No deaths occurred in either group. The patients in the household-voltage group were significantly younger. High-voltage electrical injuries occurred in an older patient population and required more aggressive care and surgical intervention. This was evident at the time of initial evaluation. Based on these data, healthy children with small partial-thickness electrical burns and no initial evidence of cardiac or neurovascular injury do not appear to need hospital admission.

The interrelationships between wound management, thermal stress, energy metabolism, and temperature profiles of patients with burns.

This prospective randomized study was performed to evaluate the metabolic and thermal responsiveness of patients with burns to thermal stress with three protocols of wound care: group I (n = 7) treated with dressings and variable ambient temperature selected for patients subjective comfort; group II (n = 7) treated without dressings and variable ambient temperature for patient comfort; group III (n = 6) treated without dressings and ambient temperature of 25 degrees C, electromagnetic heaters were set to achieve patient subjective comfort; and group IV (n = 6) healthy volunteers. After baseline partitional calorimetry was performed, individual patients were cold-challenged while subjectively comfortable by sequentially lowering either the ambient temperature or the output from the electromagnetic heaters. Heat balance and temperatures were obtained after each perturbation in external energy support. For patients in groups I and II, subjective perception of thermal comfort (warm, neutral, neutral and fed, cool, or cold) was more strongly correlated (p < 0.02) with the changes in the rate of heat production than the actual ambient temperature. For patients treated with electromagnetic heaters, changes in heat production were most strongly correlated with the energy output from the electromagnetic heaters. Even though the environmental conditions required to achieve a particular level of comfort are quite different between treatment groups, the difference in temperature between the patient's surface and ambient is approximately the same for groups I, II, and IV for each subjective state.(ABSTRACT TRUNCATED AT 250 WORDS)

Sequential excision and grafting of the burn injuries of 1507 patients treated between 1967 and 1986: end results and the determinants of death.

The development of a more aggressive approach to burn wound management, leading to complete excision within 72 hours after burn, has led some to conclude that total early excision is a major force behind improved survival rates. We have summarized the results of treatment of 1507 patients with burn injuries treated between 1967 and 1986. Wounds were managed with use of standard topical therapy, occlusive dressings, and staged excision and grafting of full-thickness injury or deep dermal injury (not healed by 21 days). Data were analyzed with use of a logistic-regression model because, with the exception of older patient cohorts, the data did not fit the probit model. The major determinants predicting death were the percentage of body surface area burned, age, smoke inhalation, and the percentage of full-thickness burn. Concordance was 97%. These data show that aggressive sequential wound excision and grafting produces end results comparable with those achieved with complete early burn wound excision for similar age ranges and injury. Early harvest of available donor sites in patients with large burns may be more important to survival than complete early wound excision.

The effect of wound management on the interaction of burn size, heat production, and rectal temperature.

Metabolic and temperature data were collected for 56 patients with burns managed with four wound care protocols. Group I (n = 7) treated with dressings and variable ambient temperature selected for patient subjective comfort; group II (n = 7) managed without dressings and variable ambient temperature for patient comfort; group III (n = 6) no dressings, ambient temperature of 25 degrees C and the output of electromagnetic heaters adjusted for patient comfort; group IV (n = 36) dressings and ambient temperature of 28 degrees C. All groups were cold challenged: groups I and II by sequentially lowering ambient temperature, group III by decreasing the electromagnetic heater output, and group IV by removing dressings with ambient temperature remaining at 28 degrees C. Only groups II and IV demonstrated correlation between percent body surface area burn and heat production. The slope of the regression for group IV neutral was significantly less than that for group IV cold and group II neutral and cold. The relationship between percent body surface area burn and rectal temperature for groups I, II, and III neutral was equal to .03 degrees C increase in rectal temperature per 1% body surface area burn (Y = 37 + 0.03; r = 0.74; df 18; p < 0.01) and was not significantly different when cold. This predicts a 1.5 degrees C increase in rectal temperature for a patient with a 50% body surface area burn who does not have sepsis.(ABSTRACT TRUNCATED AT 250 WORDS)

Energy balance studies and plasma catecholamine values for patients with healed burns.

We report heat balance studies and plasma catecholamine values for 49 children and young adults with healed burn wounds (age range 0.6 to 31 years and burn range 1% to 82% body surface area burned; mean 41%). All measurements were made during the week of discharge. Heat production for patients with healed burns was not significantly different from predicted normal values. However, compartmented heat loss demonstrated a persistent increment in evaporative heat loss that was secondary to continued elevation of cutaneous water vapor loss immediately after wound closure. A reciprocal decrement in dry heat loss was demonstrated (as a result of a cooler average surface temperature, 0.84 degree C cooler than the average integrated skin temperature of five normal volunteers who were studied in our unit under similar environmental conditions). Mean values for plasma catecholamines were in the normal range: epinephrine = 56 +/- 37 pg/ml, norepinephrine = 385 +/- 220 pg/ml, and dopamine = 34 +/- 29 pg/ml. In conclusion, patients with freshly healed burn wounds have normal rates of heat production; however, there is a residual increment in transcutaneous water vapor loss, which produces surface cooling and decreased average surface temperature, which in turn lowers dry heat loss by an approximately equivalent amount.

Alterations in plasma copper, zinc, and ceruloplasmin levels in patients with thermal trauma.

This review was undertaken to elucidate the trends in copper, zinc, total serum protein, and ceruloplasmin levels in patients with thermal trauma. Medical records of pediatric and adult patients were retrospectively reviewed. The findings showed a significant linear decline in mean plasma copper, ceruloplasmin, and total serum protein during the first three days postburn, followed in general by a gradual rise in levels; however, patients with burns larger than 60% TBSA maintained copper, zinc, and ceruloplasmin levels significantly below the lower limits of normal during the observation period. Significant decrements in copper, zinc, total serum protein, and ceruloplasmin levels have been demonstrated in these patients. Trace metal determinations should be obtained in patients with significant burns soon after admission and routinely throughout their hospital course. Specific trace metal supplementation should be administered when indicated.

Alteration in gastrointestinal peptides after thermal injury in humans.

Alterations in gastrointestinal function are common after thermal injury in humans. The peptide hormones gastrin and cholecystokinin are known to exert effects on gastric and biliary motility and on secretory function and to induce trophic changes in gut mucosa. The effect of injury on these hormones has received little attention. Six patients with burns were studied while receiving a combination of regular diet and continuous enteral feeding. Four healthy members of the nursing staff served as the control group. Blood was drawn every 4 hours for 24 hours. Gastrin and cholecystokinin were analyzed by radioimmunoassay. Patients with burns demonstrated significantly higher levels of gastrin and lower levels of cholecystokinin when compared with the control group. Patients with burns also failed to demonstrate the normal circadian variation in these peptides.

Absence of postburn hypermetabolism in a group of children with serious burns.

Hypermetabolism proportional to wound size is the expected response in patients who sustain large burns. This metabolic response persists until wound closure is achieved. The value of this response to the injured host remains unproven. Between 1978 and 1991, 104 patients with burns covering 30% or more of the body surface area underwent partitional calorimetry as a component of various research protocols. Thirteen of these patients failed to demonstrate an increase in metabolic rate as compared with a control group. These patients without hypermetabolism were compared with case-matched patients who demonstrated the expected increase in metabolic rate. Although they were not hypermetabolic in response to the burn injury, five of these patients were exposed to a cold stress and were able to increase their metabolic rate appropriately. The failure to mount a hypermetabolic response did not impact the clinical course as measured by survival, length of hospital stay, or maximum weight loss.

The pharmacokinetics of ibuprofen after burn injury.

Ibuprofen is an effective antipyretic in the postburn period and produces associated decrements in the hypermetabolic response. Burn injury is capable of altering the kinetics of many drugs, making the predictable use of agents such as ibuprofen difficult. Ten patients with serious burns were studied after the administration of 10 mg/kg ibuprofen suspension. The half-life varied from 1.4 to 5.1 hours, depending on the site of administration and/or the presence of solid food. The reported half-life for ibuprofen suspension is 1.8 to 2 hours. Burn size did not alter ibuprofen half-life or area under the time-concentration curve. Maximum ibuprofen concentration varied greatly, depending on route of administration. Time to maximal temperature reduction was between 2 and 3 hours after drug administration. Although the precise level of ibuprofen needed for cyclooxygenase inhibition is unknown, enteral administration results in levels below the targeted 10 to 20 mcg/ml for much of the traditional 6-hour dosing interval. Future studies with ibuprofen in the burn population must standardize more than just total dose.