Joan M. Weber

Nosocomial infections in pediatric patients with burns

BACKGROUND Nosocomial infections (NI) are believed to occur more commonly in patients with burns than in patients undergoing surgery, but benchmark rates have not been well described, and widely accepted definitions of NI in patients with burns are not available. We present a clinically useful set of definitions for NI for the pediatric burn population and provide benchmark infection rates for NI at selected sites. METHODS Centers for Disease Control and Prevention definitions were modified to more accurately describe nosocomial burn infection and secondary bloodstream infections (BSI) in the burn population. A surveillance system was developed and included calculation of NI rates by 1000 patient or device days, stratified into one of three risk groups (< 30% burn injury, 30% to 60% burn injury, and > 60% burn injury). All patients with acute burns admitted from January 1990 to December 1991 were included, and NI rates were calculated for burn infection, primary and secondary BSI, ventilator-related pneumonia and urinary catheter-related urinary tract infection (UTI). RESULTS Overall 12.5% of patients with central venous catheters had development of primary BSI for a rate of 4.9/1000 central venous catheter-days. Incidence of secondary BSI was 5.8% of patients for a rate of 5.3/1000 patient-days. Incidence of burn infection was 10.1% of patients for a rate of 5.6/1000 patient-days. Incidence of ventilator-related pneumonia was 17.5% of patients for a rate of 11.4/1000 ventilator-days. Incidence of urinary catheter-related UTI was 17.9% of patients, for a rate of 13.2/1000 urinary catheter-days. When rates were stratified by risk groups, incidence increased with increasing burn size for secondary BSI (p < or = 0.0001) and urinary catheter-related UTI (p = 0.08), although rates based on number of patient-days or device-days more accurately reflected risk of infection over time. CONCLUSIONS Infection remains a cause of significant morbidity and death for patients with burns. The definitions and benchmark rates reported here may be useful in evaluation of NI surveillance strategies and calculation of infection rates, which could then be used to evaluate current treatment modalities and improve outcomes for the burn population.

Early burn center transfer shortens the length of hospitalization and reduces complications in children with serious burn injuries.

Prompt transfer of the child with acute burns can be difficult from distant or inaccessible locations, and it is believed that the outcomes of children with serious burns whose transfer to a specialized burn care facility is delayed may be compromised. A 4-year experience with 16 consecutive children with serious burns (> or =20% of the body surface area) whose transfer to a burn care facility was delayed for 5 or more days was reviewed to document the difficulties that can follow such delays. These 16 children had an average age of 8.6+/-1.6 years and an average wound size of 57.6%+/-5.8% of the body surface area, and they arrived a mean of 16.3+/-3.4 days after the injury (range, 5 to 44 days). These children had undergone an average of 1 operation, excluding escharotomies, at referring facilities. Only 4 (25%) of the children had no infectious focus at transfer, and at admission resistant bacteria were recovered from 9 (56%) of the children and fungal organisms were found in 10 (63%). Compared with a concurrently managed matched control group of patients admitted to the burn center within 24 hours of injury, the delayed-transfer group had statistically significantly more bacteremia, renal dysfunction, wound sepsis, and central venous catheter days. It was also more expensive to manage these children; the delayed-transfer group required statistically significantly longer to achieve 95% wound closure, and they had greater total lengths of hospital stay and more rehabilitation days. The early transfer of children with serious burns to a specialized burn center may truncate hospitalization and thereby reduce costs.

Permissive Hypercapnia as a Ventilatory Strategy in Burned Children: Effect on Barotrauma, Pneumonia, and Mortality

OBJECTIVE To document the incidence of barotrauma, pneumonia, and respiratory death associated with a mechanical ventilation protocol based on permissive hypercapnia in pediatric burn patients. DESIGN Retrospective review. MATERIALS AND METHODS Patients were managed using a mechanical ventilation protocol based on permissive hypercapnia, tolerating moderate (pH > 7.20) respiratory acidosis to keep inflating pressures below 40 cm H2O. MAIN RESULTS Over a 2.5-year interval, 54 burned children (11% of 495 acute admissions) with an average age of 6.5 years (range 5 weeks to 17 years), average burn size of 44% (range 0 to 98%), and median burn size of 46% required mechanical ventilatory support for an average of 12.5 days (range 1 to 56 days). Inhalation injury was diagnosed in 34 (63%) of the children and 72% percent were admitted within 24 hours of injury. Overt barotrauma occurred in 5.6% of the patients, pneumonia in 32%, and respiratory death in 0%. CONCLUSIONS A conventional ventilation protocol based on permissive hypercapnia is associated with acceptable rates of barotrauma and pneumonia. The low incidence of respiratory death associated with this strategy suggests that it also minimizes ventilator-induced lung injury.

Surveillance of burn wound infections : A proposal for definitions

The diagnosis of burn wound infections is a subjective art, with no recent attempts to standardize or validate the definitions of terms used to discuss such infections. The Centers for Disease Control included definitions of types of burn wound infections in its definitions for nosocomial infections in 1988. Although the other Centers for Disease Control criteria for nosocomial infections have epidemiological applications, its criteria for burn wound infections have neither clinical nor epidemiological value to burn centers and their health care providers. With the approval of the Board of Trustees of the American Burn Association, the authors of this article formed a working subcommittee of the Committee on the Organization and Delivery of Burn Care. Definitions of burn wound infections are presented for consideration for application in either of 2 areas: (1) surveillance of burn wound infections in burn centers and (2) standardized criteria for multicenter clinical trials or national registries.

Mechanical and infectious complications of central venous cannulation in children : Lessons learned from a 10-year experience placing more than 1000 catheters

We sought to better describe the expected incidence of mechanical and infectious complications associated with central venous cannulation of critically ill children. We undertook a retrospective analysis of a prospective data collection of 1056 consecutive percutaneous central venous catheters inserted under the supervision of an experienced surgeon. There were 245 (23%) subclavian (SC), 118 (11%) internal jugular (IJ), and 693 (66%) femoral (F) catheters placed in 289 children with an average age of 6.4 ± 5.1 years (range, 4 weeks to 18 years) admitted to a burn intensive care unit. Catheter sepsis occurred in 7.4% of SC, 7.6% of IJ, and 4.9% of F catheters (NS, P = .25), for an overall sepsis rate of 5.8%. The number of catheter lumens did not impact infection rate. Infection rates increased in catheters left in situ more than 10 days, increasing to 37.5% at 14 days. Acute mechanical complications occurred in three insertions (0.3%), including two (0.8%) SC, zero (0%) IJ, and one (0.1%) F catheters (NS, P = .20). All three were arterial cannulations that were recognized and treated successfully without surgery. There were no pneumothoraces, vascular lacerations, acute thromboses, or catheter emboli. There were six (0.6%) cases of deep venous thrombosis that occurred in cannulated sites: one (0.4%) SC, two (1.6.%) IJ, and three (0.4%) F sites (NS, P = .23). Patient age did not influence complication rates. A total of 239 (23%) of the CVCs were placed in infants less than 24 months; 273 (26%) 2 to 5 years, 259 (25%) 6 to 10 years, and 285 (27%) >10 to 18 years. Catheter sepsis occurred in 6.7%, 5.9%, 6.2%, and 4.6%, respectively (NS, P = .75). There was no difference in rates of infection or mechanical complication between younger and older children. When closely supervised by an experienced surgeon, a low rate of infection (5.8%), acute mechanical complication (0.3%), and deep venous thrombosis (0.6%) accompanies central venous cannulation of critically ill children.

Femoral venous access is safe in burned children: An analysis of 224 catheters☆☆☆★★★

OBJECTIVE To document the incidence of septic and mechanical complications associated with femoral venous catheters in a subgroup of patients thought to be at particularly high risk of both: young children with large burns. DESIGN An analysis of data collected prospectively on all femoral venous catheters placed during a 4-year period at a regional pediatric burn facility. RESULTS There were 224 femoral catheters placed in 86 children with an average age of 5.3 +/- 5.1 years and an average burn size of 38% +/- 23%. Catheters were left in place for a mean duration of 5.7 days. Catheter-related sepsis occurred with 4.9% of the catheters, and mechanical complications occurred in 3.5% of the patients. There was no statistically significant association between the risk of catheter sepsis and the placement of catheters through burned versus unburned skin. Similarly, the risk of sepsis was equivalent between lines placed over a guide wire and those placed of a new site. CONCLUSION Femoral venous catheters are safe in burned children and are associated with a low incidence of infectious and mechanical complications.

Management of severe toxic epidermal necrolysis in children

Toxic epidermal necrolysis (TEN) is a severe form of erythema multiforme that results in extensive epidermal sloughing; the condition is associated with a mortality of up to 70%. From 1991 to 1998, 10 children with severe toxic epidermal necrolysis were referred to a regional pediatric burn facility. Wounds were managed with strategy involving prevention of wound desiccation and superinfection, including the frequent use of biologic wound coverings. Children unable to guard their airway because of extensive oropharyngeal involvement were prophylactically intubated. Enteral nutrition was stressed. Steroids were not used and antibiotics were administered to managed specific foci of infection only. The 2 boys and 8 girls had an average age of 7.2+/-1.8 years (range 6 months to 15 years) and sloughed surface area of 76+/-6% of the body surface (range 50 to 95%). Antibiotics (3 children), anticonvulsants (3 children), nonsteroidals (2 children), and viral syndrome or unknown agents (2 children) were felt to have triggered the syndrome. Six children (60%) required intubation for an average of 9.7+/-1.8 days (range 2 to 14 days). Buccal mucosal involvement occurred in 9 (90%) and ocular involvement in 9 (90%). Although infectious complications were common (2 pneumonias, 2 urinary infections, 1 bacteremia, 2 central line infections, and 2 candidemias), all children survived after lengths of stay in the burn unit averaging 19+/-3 (range 6 to 40) days. The most common long-term morbidity was keratitis sicca (2 children, 20%), finger nail deformities (3 children, 30%), and variegated skin pigment changes (5 children, 50%). Although having both a cutaneous and visceral wound that predispose them to infectious complications, most children with TEN will survive if managed with a strategy emphasizing biologic wound closure, intensive nutritional support, and early detection and treatment of septic foci. Burn units have the resource set required to manage severe TEN and early referral of such children may have a favorable impact on survival.

Central venous catheter sepsis with weekly catheter change in paediatric burn patients: an analysis of 221 catheters☆

To document the risk of catheter sepsis associated with central venous catheter changes every 7 days in paediatric burn patients, and analysis of data collected prospectively on 234 such catheters was performed. During an 18-month period there were 301 acutely burned children admitted to a regional paediatric burn facility of whom 53, with an average burn size of 42 per cent TBSA, required 234 central venous catheters. A central venous catheter management protocol was followed which included catheter changes every 7 days. If insertion sites were clean and uninflamed, catheters were replaced by guidewire and the original catheter tip was semiquantitatively cultured. Catheters were replaced to a new site if insertion sites appeared inflamed or catheter tips grew 15 or more colony forming units. Overall, 3.2 per cent (10.9 per cent by Centers for Disease Control definition) of central venous catheters were associated with sepsis. When catheters were replaced by guidewire from one to three times, catheter sites were used for a mean of 15.6 days without an increased rate of line sepsis. There was no difference in sepsis rates between catheters placed at a new site or replaced by guidewire. There were no deaths attributed to catheter-related sepsis. We conclude that a protocol allowing for catheter change to a new site, or replacement by guidewire, every 7 days was associated with a low risk of catheter sepsis in paediatric burn patients.

Intravenous colistin for the treatment of multi-drug resistant, gram-negative infection in the pediatric burn population

The rising incidence of multi-drug resistant (MDR) gram-negative infections in the intensive care unit (ICU) continues to challenge clinicians and has resulted in reemergence of the glycopeptide antibiotic colistin. Over the past 11 years, 14 patients at a tertiary pediatric burn center were treated with colistin for gram-negative infections resistant to all tested antibiotics. This study reviews the safety of such treatment and the outcome for this cohort of patients. All hospitalized patients treated with intravenous colistin between 1990 and 2005 were identified. A retrospective chart review was performed for each patient. Demographic data, along with information regarding the type and severity of injury, were collected. Data with respect to microbiology, renal status, and neurological events were also noted. Over an 11-year period, we identified 14 children infected with pan-resistant gram-negative organisms requiring 16 courses of colistin. Two children (14.3%) developed significant rises in serum creatinine concentration; however, no child required renal replacement therapy or developed neurologic complications attributable to colistin. Favorable response rate was 78.6% (11/14), and overall mortality was 14.3% (2/14); both deaths were attributed to sepsis. In our experience with 14 children treated with intravenous colistin, two developed a significant elevation in serum creatinine concentration during the course of therapy and neurotoxicity was not reported. Colistin should be dispensed with great caution, but it appears to have an acceptable safety profile in children and may be used in select cases of infection with highly resistant gram-negative organisms.

Control of naeethicillin-resistant Staphylococcus aureus in a pediatric burn unit

BACKGROUND Control of methicillin-resistant Staphylococcus aureus (MRSA) is particularly difficult in burn units, which are often cited as sources of hospital-wide MRSA outbreaks. We developed a successful MRSA control program and document here its apparent effectiveness in controlling MRSA transmission in a pediatric burn unit. METHODS An MRSA control program that included surveillance culturing, clinician feedback, flexible, site-specific isolation, and a list of known carriers was consistently applied in a pediatric burn unit through a 7-year period. Microbiology reports of MRSA isolates from patients and environmental surfaces and records of all patients from whom MRSA was isolated were reviewed. RESULTS During calendar years 1985 through 1991, a total of 991 acutely burned children were admitted to the Boston unit of the Shriners Burns Institute. Forty MRSA cases (4%) were identified. One patient both had MRSA at admission and met our criteria for nosocomial MRSA. Of the remaining 39 patients, 11 had MRSA at admission and 28 had nosocomial MRSA. There were 17 wound infections, two cases of pneumonia, and two bloodstream infections. No deaths were attributed to MRSA sepsis. CONCLUSION An MRSA control program including surveillance culturing, clinician feedback, flexible, site-specific isolation, and a list of known carriers is associated with a low rate of nosocomial MRSA in a pediatric burn unit.