Pediatric trauma susceptibility to sepsis

OBJECTIVE

The purpose of this review is to review how pediatric trauma may predispose children to sepsis.

DESIGN

The information discussed in this report is derived from a recent literature review of pediatric trauma and related topics and discussion at an international consensus conference on pediatric sepsis.

MEASUREMENTS AND MAIN RESULTS

There is a paucity of evidence on sepsis-related complications in pediatric trauma patients. Severe traumatic brain injury is a leading predisposing factor for sepsis complications. Excluding burn trauma, traumatically injured children without severe head injury rarely succumb to overwhelming sepsis.

CONCLUSIONS

Patients with multiple traumatic injuries are frequently admitted to the intensive care unit, and because head injury is the most common ailment, unconscious patients with a combination of injuries that include head injury will regularly require mechanical ventilation and central venous access and are at risk for life-threatening nosocomial infections. Outside of pulmonary contusions, organ-specific causes of infection are infrequent.

Collagen denaturation can be quantified in burned human skin using polarization-sensitive optical coherence tomography

Quantifiable prognostic indicators are of considerable practical value following thermal injury. Collagen is a major component of the skin, and is known to undergo denaturation at the elevated temperatures associated with burns. The purpose of this study was to determine whether a recently developed, non-invasive imaging technique could detect and quantify collagen denaturation in burned human skin. Polarization-sensitive optical coherence tomography (PS-OCT) imaging was used to quantify collagen birefringence in normal human skin, and in skin excised from burn patients. Images were acquired and displayed in 1s, and demonstrated qualitative differences between normal and partial-thickness burned human skin. Birefringence loss due to thermal denaturation of collagen was quantified, with mean phase retardation rates for samples of 26 normal and 26 burned skin sites determined to be 0.401 +/- 0.020 and 0.249 +/- 0.017 degrees /microm, respectively (mean +/- S.E.M.), with this difference in sample means shown to be statistically significant (P < 0.000001). Analysis of the accuracy of the technique indicated that PS-OCT measurements may be made with resolution sufficient to distinguish between burns of varying severity. In conclusion, PS-OCT is capable of imaging and quantifying collagen denaturation in burned human skin, providing a new parameter against which post-injury outcome may be compared.

Fibroblasts improve performance of cultured composite skin substitutes on athymic mice

BACKGROUND

This study investigated the impact of adding human fibroblasts to a cultured composite skin substitute model of cultured human keratinocytes and acellular human dermis.

METHODS

Skin substitutes were prepared by seeding human keratinocytes on the papillary side of acellular dermis with or without seeding fibroblasts on the reticular side. Performance of the grafts was compared both in vitro by histology and in vivo on surgically created full-thickness wounds on athymic mice. Graft size and contraction were measured and immunohistochemical stains were done to reveal vascularization.

RESULTS

Skin substitutes with fibroblasts formed thicker epidermis than skin substitutes without fibroblasts. When transplanted onto athymic mice, skin substitutes with fibroblasts maintained their original size with only 2% contraction. In contrast, skin substitutes without fibroblasts showed 29% contraction. Vascular basement membrane specific mouse CD31staining and endothelial cell specific mouse collagen type IV staining revealed vascularization as early as 1 week posttransplant in grafts with fibroblasts, and was significantly higher than grafts without fibroblasts at 2 weeks.

CONCLUSIONS

Addition of fibroblasts to keratinocyte based composite skin substitutes improves epidermis formation, enhances vascularization and reduces contraction.

Short-term enteral glutamine does not enhance protein accretion in burned children: a stable isotope study

OBJECTIVE

Glutamine is a nonessential amino acid that, in recent years, has been found to play important roles in several metabolic and immunologic processes. It has been theorized that, in a stressed state, it may become "conditionally essential" because the patient's ability to manufacture glutamine may not be adequate to meet their needs under this condition. We chose to evaluate the ability of 48 hours of enteral glutamine to enhance immediate nitrogen accretion in stressed pediatric burn patients.

METHODS

Nine children with serious burns who were tolerating tube feedings were enrolled in a human studies committee-approved protocol in which they received 48 hours of enteral feedings with glutamine replacing 20% of essential and nonessential amino acids and 48 hours of isonitrogenous, isocaloric standard enteral feedings. This interval was chosen to help ensure that the study periods were comparable from a metabolic perspective. At the end of each period, protein kinetics were determined by a primed constant infusion of L-[1-(13)C] leucine tracer. The order of the studies was randomized. Seven children completed both phases of the study. Results were compared by paired t test and are presented as mean +/- standard error of the mean.

RESULTS

During the glutamine feeding period, the leucine flux and leucine oxidation rate were significantly lower than those in the conventional feeding period. This reflects a reduction in total leucine intake from 80 +/- 11 to 62 +/- 10 micromol/kg per hour. However, there was no significant difference in the net balance of leucine accretion into proteins between these 2 dietary periods, which indicated that enriched glutamine feeding for 48 hours did not result in an immediate whole body protein gain in this group of pediatric patients. In addition, plasma glutamine concentration showed a moderate increase after 48 hours of supplementation but did not reach significance.

CONCLUSION

Rapid protein accretion does not occur with short-term enteral glutamine supplementation. Several days of glutamine supplementation may be required to restore plasma glutamine levels and stimulate protein synthesis.

Short-term propofol infusion as an adjunct to extubation in burned children

Children who require intubation as a component of their burn management generally need heavy sedation, usually with a combination of opiate and benzodiazepine infusions with a target sensorium of light sleep. When extubation approaches, the need for sedation to prevent uncontrolled extubation can conflict with the desire to lighten sedation enough to ensure that airway protective reflexes are strong. The several hours' half-life of these medications can make this period of weaning challenging. Therefore, the hours preceding extubation are among the most difficult in which to ensure safe adequate sedation. The pharmacokinetics of propofol allow for the rapid emergence of a patient from deep sedation. We have had success with an extubation strategy using short-term propofol infusions in critically ill children. In this work, children were maintained on morphine and midazolam infusions per our unit protocol, escalating doses as required to maintain comfort. Approximately 8 hours before planned extubation, these infusions were decreased by approximately half and propofol infusion added to maintain a state of light sleep. Extubation was planned approximately 8 hours later to allow ample time for the chronically infused opiates and benzodiazepines to be metabolized down to the new steady-state level. Thirty minutes before planned extubation, propofol was stopped while morphine and midazolam infusions were maintained at the reduced level. When the children awakened from the propofol-induced state of light sleep, they were extubated while the reduced infusions of morphine and midazolam were maintained. These were subsequently weaned slowly, depending on the child's need for ongoing pain and anxiety medication, per our unit protocol to minimize the incidence of withdrawal symptoms. Data are shown in the text as mean +/- standard deviation. These 11 children (eight boys and three girls) had an average age of 6.6 +/- 5.6 years (range, 1.2-13 years), average weight of 36.9 +/- 28.7 kg (range, 9.3-95 kg), and burn size of 43 +/- 21.4% (range, 10-85%). Three children had sustained scald burns and eight had flame injuries with associated inhalation injury. They had been intubated for an average of 12.7 +/- 10.9 (range, 2-33 days). Morphine infusions immediately before the initiation of propofol averaged 0.26 +/- 0.31 mg/kg/hour (range, 0.04-1.29 mg/kg/hr) and midazolam averaged 0.15 +/- 0.16 mg/kg/hr (range, 0.06-0.65 mg/kg/hr). Morphine infusions after beginning propofol and at extubation averaged 0.16 +/- 0.16 (range, 0.04-0.65 mg/kg/hr) and midazolam averaged 0.09 +/- 0.08 mg/kg/hr (range, 0.02-0.32 mg/kg/hr). Propofol doses after initial titration during the first hour of infusion averaged 3.6 +/- 2.9 mg/kg/hr (range, 0.4-8.1 mg/kg/hr). Nine of the 11 children (82%) were successfully extubated on the first attempt. Two required reintubation for postextubation stridor 2 to 6 hours after extubation but were successfully extubated the next day after a short course of steroids, again using the same propofol technique. All were awake at extubation and went on to survive. Morphine and midazolam infusions were gradually weaned, and there were no withdrawal symptoms noted. Although prolonged (days) infusions of propofol have been associated with adverse cardiovascular complications in critically ill young children and should probably be avoided, short-term (in hours) use of the drug can facilitate smooth extubation.

Favorable Short- and Long-Term Outcomes of Prolonged Translaryngeal Intubation in Critically Ill Children

In those children who require protracted mechanical ventilation, we use long-term intubation in order to avoid the consequences of tracheostomy in young children. A retrospective 9-year review was performed to document the efficacy and safety of this practice. A retrospective review of children admitted from January 1, 1991, to December 31, 1998, who required mechanical ventilatory support for at least 7 consecutive days was performed. Data are presented as mean +/- standard deviation. There were 98 children, ventilated for a total of 1967 days, who satisfied review criteria. They had an average age of 6.1 +/- 5.3 years (range, 3 months to 17 years) a total body surface area burn of 53 +/- 25% (range, 0-100%), and 71 of 98 (72%) had suffered an inhalation injury. They were ventilated for 19.7 +/- 16.8 days (range, 7-92 days) and were hospitalized for 67.8 +/- 48.9 days (range, 9-211 days). Ninety-three percent (91 of 98) of the patients were maintained on morphine infusions at a mean hourly rate of 0.35 +/- 0.33 mg/kg/hr (range, 0.01-4.38) and 78% (76 of 98) on midazolam infusions at a mean hourly rate of 0.14 +/- 0.17 mg/kg/hr (range, 0.01-1.82). Neuromuscular blocking agents were administered in 39% (38 of 98) of patients during all or part of 355 (18%) of the 1967 ventilator days. Patients were ventilated with an oral endotracheal (ET) tube in 82% of ventilator days and nasal ET tube in 18% of ventilator days. Two patients (2%) required tracheostomies for long-term management, and five patients (5.1%) died during the study period unrelated to airway issues. There were five unplanned extubation events, for an incidence rate of 2.54 per 1000 ventilator days. All patients were reintubated successfully. Thirteen ET tubes needed to be changed for issues such as leaking cuffs. Patients were followed up for a mean of 2.99 +/- 2.24 years (range, 1 month to 8 years). Possible sequelae related to prolonged intubation were noted in follow-up visits in 8 patients, including sinusitis (one; resolved without treatment), subglottic stenosis (one; required reconstructive surgery), persistent cough (three; all resolved spontaneously), occipital breakdown because of ET ties (one; healed after 1 month), soft voice (two; resolved spontaneously), and decreased pharyngeal sensation (one; resolved without treatment). Translaryngeal intubation is a safe and effective method to provide long-term ventilatory support in children.

Trauma to adult bicyclists: a growing problem in the urban environment

The proportion of adults involved in serious bicycle accidents has increased in the last two decades. The majority of the bicycle injury prevention efforts, however, are directed toward child riders. The authors performed a retrospective review of injury statistics from the Massachusetts Hospital Discharge Data Set, 1994-1999, the Massachusetts Emergency Department Injury Surveillance System, 1999, and the trauma registry of an Urban Level I Trauma Centre, 1993-2000. Massachusetts's state-wide injury data reveals a 30% increase in hospital charges between 1994 and 1999 for adults following bicycle falls and collisions with concomitant stability in the charges for children. In the years 1993-2000, 60% of patients requiring inpatient care at the Study Centre for Bicycle Related Injuries were over 16 years of age. Fifty-one percent of patients were without a helmet. Positive blood alcohol tests were present in 35 (16%) of the 222 patients. Forty-six (75%) of patients suffering closed head injury were not helmeted. Adult bicycle trauma is a significant health and financial problem in the urban state of Massachusetts. Bicycle education and legislation emphasising safe bicycling practice, the protective effects of helmets, and the danger of cycling under the influence of alcohol may help alleviate this problem.

Noncontact Electrosurgical Grounding Is Useful in Burn Surgery

Grounding patients with large burns to facilitate the use of electrocautery devices during surgery is commonly difficult because of the paucity of available grounding sites. The Mega 2000 Patient Return Electrode System (Megadyne Medical Products, Draper, UT) is an electrode designed to provide electrical return to facilitate function of electrocautery devices without direct patient contact. It accomplishes this by having a very large surface area (720 square inches) in the form of a reusable pad placed on the operating table that is covered by an impermeable drape and clean sheet beneath the patient. We used this noncontact device in 25 operations of 17 children with large burns and limited availability of traditional grounding sites. The patients had an average age of 8.8 + 4.6 years (range, 14 months-14 years), average burn size of 55 + 33% of the body surface (range, 10-95%), and average weight of 33.0 + 17.9 kg (range, 9-75 kg). Operations included 22 excision and grafting operations, an axillary release, a neck release, and bilateral groin releases. The device functioned well in all cases. There were no cutaneous burns observed. No additional traditional devices required placement. We found the device useful in burn surgery in those cases where there is a paucity of traditional grounding sites available.

Cerebral Fractional Anisotropy Score in Trauma Patients:A New Indicator of White Matter Injury After Trauma

OBJECTIVE

Previous studies evaluating quantitative cerebral white matter diffusion anisotropy indexes have shown alteration in patients after trauma. To date, no clinically applicable scale exists by which to gauge and test the relevance of these findings. We propose the cerebral fractional anisotropy score in trauma (C-FAST) as an index of white matter injury, and we correlate C-FAST with several predictor and outcome variables.

MATERIALS AND METHODS

Fifteen patients were randomly selected from the trauma surgery service. Thirty control patients were randomly selected from the emergency department. All patients were subjected to MRI evaluation, including a diffusion-weighted sequence. Data extracted from the record of each subject included Glasgow Coma Scale, revised trauma score, Abbreviated Injury Scale, initial head CT results, patient disposition, length of hospital stay, and length of stay in intensive care unit. Region of interest measurements were made in fractional anisotropy maps in each of 12 white matter regions. Univariate statistics and a two-tailed t test were performed on the raw fractional anisotropy data. Data were then dichotomized using thresholds from univariate statistics. A C-FAST score was devised from the dichotomized data. Logistic regression analyses were performed among the C-FAST, outcome, and predictor data.

RESULTS

Good correlation was noted between the C-FAST and death, hospital stay greater than 10 days, and intensive care unit stay greater than 5 days. Correlation with discharge to rehabilitation facility was good when adjusted for age and sex. Glasgow Coma Scale, revised trauma score, and Abbreviated Injury Scale show good correlation as predictors of a critical C-FAST.

CONCLUSION

The C-FAST is a promising index derived from MRI diffusion fractional anisotropy measurements that shows successful correlation with outcome and predictor variables. A larger investigation is needed to verify the validity and stability of the correlations.

Current management of purpura fulminans: a multicenter study

Seven burn centers performed a 10-yr retrospective chart review of patients diagnosed with purpura fulminans. Patient demographics, etiology, presentation, medical and surgical treatment, and outcome were reviewed. A total of 70 patients were identified. Mean patient age was 13 yr. Neisseria meningitidis was the most common etiologic agent in infants and adolescents whereas Streptococcus commonly afflicted the adult population. Acute management consisted of antibiotic administration, volume resuscitation, ventilatory and inotropic support, with occasional use of corticosteroids (38%) and protein C replacement (9%). Full-thickness skin and soft-tissue necrosis was extensive, requiring skin grafting and amputations in 90% of the patients. One fourth of the patients required amputations of all extremities. Fasciotomies when performed early appeared to limit the level of amputation in 6 of 14 patients. Therefore, fasciotomies during the initial management of these patients may reduce the depth of soft-tissue involvement and the extent of amputations.

Multicenter postapproval clinical trial of Integra dermal regeneration template for burn treatment

The safety and effectiveness of Integra Dermal Regeneration Template was evaluated in a postapproval study involving 216 burn injury patients who were treated at 13 burn care facilities in the United States. The mean total body surface area burned was 36.5% (range, 1-95%). Integra was applied to fresh, clean, surgically excised burn wounds. Within 2 to 3 weeks, the dermal layer regenerated, and a thin epidermal autograft was placed. The incidence of invasive infection at Integra-treated sites was 3.1% (95% confidence interval, 2.0-4.5%) and that of superficial infection 13.2% (95% confidence interval, 11.0-15.7%). Mean take rate of Integra was 76.2%; the median take rate was 95%. The mean take rate of epidermal autograft was 87.7%; the median take rate was 98%. This postapproval study further supports the conclusion that Integra is a safe and effective treatment modality in the hands of properly trained clinicians under conditions of routine clinical use at burn centers.

Burns

During the past 20 yrs, as burn care has evolved as a specialty of surgery, survival and outcome quality have soared. Public expectations for survival and long-term outcomes are at previously unprecedented levels. These changes are the result of a number of advances in aspects of burn care that have occurred in parallel and have fostered increasing regionalization of this resource-intensive activity into fewer specialized centers. These are complex hospitalizations and can be divided into four phases: initial evaluation and resuscitation, initial wound excision and biological closure, definitive wound closure, and rehabilitation and reconstruction.

Is the screening portable pelvis film clinically useful in multiple trauma patients who will be examined by abdominopelvic CT? Experience with 397 patients

The multiple trauma patient is usually initially imaged with a portable "trauma series" consisting of a lateral cervical spine film, a portable chest film, and a portable pelvis film (PPF). An investigation was performed to determine whether the screening PPF could be eliminated for multiple trauma patients being examined by abdominopelvic CT scan (APCT). A retrospective investigation analyzed all patients evaluated in our level I trauma center from 1 January to 31 December 2000 who were examined with a "trauma series" followed by an APCT scan within 8 h. The numbers and types of fractures diagnosed by PPF and by APCT were compared and correlated with clinical follow-up. Of 397 patients imaged by both PPF and APCT, 43 patients were diagnosed with 109 individual fractures by CT scan. The PPF did not detect 51 of the 109 individual fractures (47%) and failed to diagnose 9 of the 43 patients (21%) with a pelvic fracture. The PPF most often failed to detect sacral and iliac fractures. The four cases in which the PPF reported a fracture not listed in the APCT report were due to reporting errors or film artifacts. No soft tissue injuries were seen by PPF that were not also seen by APCT. We conclude that the screening PPF appears to be an unnecessary exam in multiple trauma patients about to be imaged by APCT scan.

Use of Integra artificial skin is associated with decreased length of stay for severely injured adult burn survivors

Mortality and length of stay (LOS) of survivors was examined retrospectively in 270 adults with acute burns > or =20% of body surface area to determine the effect of Integra Dermal Regeneration Template treatment on outcome. No difference in mortality was found between patients who received Integra (30%; n = 43) and patients who did not (30%; n = 227). Surviving Integra patients (n = 30) stayed longer, but they were more extensively injured than survivors who did not receive Integra (n = 158), and therefore longer hospitalizations were expected. In a subgroup analysis, mean LOS of Integra patients with two or more mortality risk factors (age > 60 years, burn size >40% body surface area, or inhalation injury; n = 15) was 63 days compared with 107 days in patients with two or more risk factors (n = 29) who did not receive Integra ( =.014). Integra use in severely injured burned adults was associated with a marked decrease in LOS.

Incidence, outcome, and long-term consequences of herpes simplex virus type 1 reactivation presenting as a facial rash in intubated adult burn patients treated with acyclovir

BACKGROUND

Increased mortality, extensive visceral involvement, and necrotizing tracheobronchitis associated with herpes viruses have been reported after burns. It is unclear whether herpes presenting as a facial rash results in outcome changes after burns.

METHODS

A retrospective study characterizing the incidence, presentation, and outcome of 14 patients with facial herpes rashes out of 95 severely burned intubated adults was performed.

RESULTS

Facial rashes attributed to herpetic infections were found in at least 15% of patients. The problem was recognized during the second week after burn. There was no difference in mortality or length of stay noted between patients with or without the infection.

CONCLUSION

The course of this infection was relatively benign in this group of acyclovir-treated patients. Even so, the lesions clearly contributed to patient discomfort and often produced fevers requiring costly investigations. Early recognition could help prevent diffuse spread of the lesions, decreasing patient discomfort and improving patient care.

Treatment of pain in acutely burned children

The child with burns suffers severe pain at the time of the burn and during subsequent treatment and rehabilitation. Pain has adverse physiological and emotional effects, and research suggests that pain management is an important factor in better outcomes. There is increasing understanding of the private experience of pain, and how children benefit from honest preparation for procedures. Developmentally appropriate and culturally sensitive pain assessment, pain relief, and reevaluation have improved, becoming essential in treatment. Pharmacological treatment is primary, strengthened by new concepts from neurobiology, clinical science, and the introduction of more effective drugs with fewer adverse side effects and less toxicity. Empirical evaluation of various hypnotic, cognitive, behavioral, and sensory treatment methods is advancing. Multidisciplinary assessment helps to integrate psychological and pharmacological pain-relieving interventions to reduce emotional and mental stress, and family stress as well. Optimal care encourages burn teams to integrate pain guidelines into protocols and critical pathways for improved care.

A multicenter review of toxic epidermal necrolysis treated in U.S. burn centers at the end of the twentieth century

Toxic epidermal necrolysis (TEN) is a potentially fatal disorder that involves large areas of skin desquamation. Patients with TEN are often referred to burn centers for expert wound management and comprehensive care. The purpose of this study was to define the presenting characteristics and treatment of TEN before and after admission to regional burn centers and to evaluate the efficacy of burn center treatment for this disorder. A retrospective multicenter chart review was completed for patients admitted with TEN to 15 burn centers from 1995 to 2000. Charts were reviewed for patient characteristics, non-burn hospital and burn center treatment, and outcome. A total of 199 patients were admitted. Patients had a mean age of 47 years, mean 67.7% total body surface area skin slough, and mean Acute Physiology and Chronic Health Evaluation (APACHE II) score of 10. Sixty-four patients died, for a mortality rate of 32%. Mortality increased to 51% for patients transferred to a burn center more than one week after onset of disease. Burn centers and non-burn hospitals differed in their use of enteral nutrition (70 vs 12%, respectively, P < 0.05), prophylactic antibiotics (22 vs 37.9%, P < 0.05), corticosteroid use (22 vs 51%, P < 0.05), and wound management. Age, body surface area involvement, APACHE II score, complications, and parenteral nutrition before transfer correlated with increased mortality. The treatment of TEN differs markedly between burn centers and non-burn centers. Early transport to a burn unit is warranted to improve patient outcome.

Long-term consequences of toxic epidermal necrolysis in children

OBJECTIVE

Toxic epidermal necrolysis (TEN) is an acute inflammatory systemic condition that involves injury not just to the skin. Historically, it has been associated with a high mortality but few long-term consequences among survivors. With improved survival, long-term consequences may be becoming more apparent. The objective of this study was to define these long-term consequences and their frequency.

METHODS

From July 1, 1991, to June 30, 2000, 11 children with severe TEN were referred to a regional pediatric burn facility. Wounds were managed with a strategy involving prevention of wound desiccation and superinfection, including the frequent use of biological wound coverings. All children survived and have been followed in the burn clinic. The records of all children were reviewed in detail.

RESULTS

Two boys and 9 girls with an average age of 7.2 +/- 1.8 years (range: 6 months-15 years) and sloughed surface area of 76 +/- 6% of the body surface (range: 50%-95%) were admitted to the burn unit for care. Antibiotics (3 children), anticonvulsants (4 children), nonsteroidals (2 children), and viral syndrome or unknown agents (2 children) were believed to have triggered the syndrome. Six (55%) children required intubation for an average of 9.7 +/- 1.8 days (range: 2-14 days). Mucosal involvement occurred in 10 (91%) and ocular involvement in 10 (91%). Lengths of stay averaged 19 +/- 3 days (range: 6-40 days). Overall follow-up averaged 14 +/- 13 months. Three children had no apparent long-term consequences of the disease and were referred to primary care follow-up after the 2-month burn clinic visit. The remaining children had follow-up averaging 23 +/- 13 months. The most common long-term morbidity involved eyes (3 children [27%]), nails (4 children [36%]), and variegated skin depigmentation (all children). One child developed vaginal stenosis from mucosal inflammation. No esophageal strictures or recurrent TEN has been diagnosed.

CONCLUSIONS

Survival has improved in children with TEN, but long-term sequelae are not infrequent. The most common long-term consequences involve the eyes, the skin, and the nails.