Analysis of anaerobic blood cultures in burned patients

Analysis of Blood Cultures from Major Burns Patients in a Tertiary Care Burn Unit in Oman

Objectives

This study aimed to review the blood stream infections of major burn patients in a tertiary care burn unit to determine the most prevalent infecting organisms in order to have a better empirical therapy protocol.

Methods

This retrospective study analysed the blood stream infection of 155 major burn (>20% Total Body Surface Area [TBSA]) patients in Khoula Hospital, Muscat, Oman between January 2014 to December 2019.

Results

The median age was 33 years and 57.42% of patients were male. The median TBSA was 38%, mortality was 25.16% and 50.9% of patients had positive blood cultures. The expired patients had higher TBSAs, Abbreviated Burns Severity Index scores and earlier first positive blood cultures. Candida was commonly grown in all the blood cultures, but the most prevalent organisms were Acinetobacter, Staphylococci, Klebsiella, Enterococcus and Pseudomonas. All Acinetobacter species are multidrug resistant. Of the 17 patients who had Kelbsiella grown in the blood culture, 8 grew multidrug-resistant Klebsiella. Only 4 patients' blood cultures grew methicillin-resistant Staphylococcus aureus. The number of blood culture samples taken ranged between 1-28 (median = 6). The first positive blood culture showed that Staphylococcus epidermidis and Acinetobacter were the most common infecting organisms.

Conclusions

Multidrug-resistant Acinetobacter was the most predominant microorganism grown from the blood cultures of major burn patients in a tertiary care burn unit. Empirical therapy should include antibiotics that are effective against this organism to reduce the mortality.

Microbiology in burns patients with blood stream infections: trends over time and during the course of hospitalization

BACKGROUND

Bloodstream infections (BSI) are a major cause of mortality in burns patients. Knowledge of the microbiology is crucial to direct empirical therapy. We sought to determine the causative microorganisms and antibiotic resistance in burns patients with BSI.

METHODS

All consecutive BSI episodes in a tertiary hospital burns unit from 2000 to 2014 were included. The following three subperiods were compared: 2000-2004, 2005-2009 and 2010-2014. Changes in BSI occurring during early and late hospitalization periods were evaluated.

RESULTS

A total of 103 BSI episodes were included. The cumulative incidence was 2.4 episodes/1000 patient days. A positive trend in the frequency of Gram-negative BSI, especially in the upsurge of Pseudomonas aeruginosa and Klebsiella spp. BSI after 2004, was observed. The most common causative pathogens in early BSI were Gram-positive microorganisms. P. aeruginosa and Klebsiella spp. became the predominant aetiology in the fourth week of hospitalization and beyond. There was a progressive increase in imipenem-resistant P. aeruginosa over time (0%, 67%, 75% in 2000-2004, 2005-2009, 2010-2014, respectively) and during the hospital stay (50% vs. 85.7%, in <7 days-BSI vs. >30 days-BSI, respectively). A higher SOFA (Sepsis-related Organ Failure Assessment) score was associated with Gram-negative BSI versus non-Gram-negative BSI (median: 2.5 vs. 0; p = 0.041).

CONCLUSIONS

There is a changing trend in the types of pathogens causing BSI in burns patients over the 14-year period and during the course of hospitalization. The problematic increase in carbapenem-resistance highlights the need for new antimicrobial stewardship policies and antibiotic prescribing protocols.

Description of Streptococcus pneumoniae infections in burn patients

BACKGROUND

Longer survival in burn patients has resulted in more infectious complications, typically with Klebsiella pneumoniae, Pseudomonas aeruginosa, Acinetobacter baumannii, and Staphylococcus aureus. Although Streptococcus pneumoniae infections are common in the community and can cause nosocomial infections, the incidence and risk factors for pneumococcal infections in burn patients is unclear.

METHODS

We performed an electronic retrospective chart review to collect rates of and risk factors for S. pneumoniae infections in patients with thermal burns from March 2003 through June 2008.

RESULTS

Of the 1838 patients admitted to the burn center, 10 were infected (0.54% incidence). Patients presented with pneumonia (seven patients, 0.38% incidence) and bacteremia (three patients, 0.16% incidence) within a week of initial burn (median 1 day, range 0-8), often in the setting of bacterial co-infection (five patients). This group was mainly young males with median 28.8% total body surface area burns; 60% had concomitant inhalational injury. Most did not have traditional risk factors for pneumococcal infection but had objective signs of infection at time of positive culture and were treated with appropriate antibiotics. Two patients in this series died, although no mortality was attributed to S. pneumoniae.

CONCLUSIONS

Pneumococcal disease is not common in burn patients and generally occurs early on in hospitalization after burn making it more likely to be a community-acquired pathogen rather than nosocomial in the burn population. It should be considered in the setting of sepsis or new pulmonary infiltrates within a week after burn, but typical empiric antibiotics against the usual burn pathogens should be adequate to also treat for pneumococcal infection.

Causes of mortality by autopsy findings of combat casualties and civilian patients admitted to a burn unit

BACKGROUND

Approximately 5% of combat-related injuries include burns. Previous studies have shown similar mortality rates between military and civilian burn casualties; but causes of death were not detailed.

STUDY DESIGN

We retrospectively reviewed autopsy reports of patients with burns treated at the US Army Institute of Surgical Research Burn Center from 2004 to 2007.

RESULTS

Of 1,255 admissions, 100 (8%) died, with autopsies performed on 74 (36 burned during military operations). Causes of death included infection (61%); disorders of the pulmonary (55%), cardiac (36%), renal (27%), gastrointestinal (27%), and central nervous (11%) systems; and multiorgan dysfunction (15%). Patients burned as a result of military operations were younger men with more associated inhalation injuries, greater severity of injury, and longer time from injury to admission and to death. They died more frequently of infection (notably fungus, Pseudomonas, and Klebsiella) and gastrointestinal complications; and those not burned in military operations had greater numbers of cardiac and renal causes of death.

CONCLUSION

Casualties of military operations are clinically different and die from different causes than patients not burned during military operations. The differences are likely reflective of a younger population, with greater severity of illness and longer times from injury to admission. Therapeutic interventions should focus on prevention of infection and gastrointestinal catastrophes in military burn casualties, which are similar to younger burn patients in the US, and minimizing cardiac complications in civilian burn casualties, who are typically older patients and possibly reflective of patients with more comorbidities.

The year in burns 2007

In the year 2007, approximately 1000 original burn research articles were published in scientific journals using the English language. This article reviews approximately 90 of these which were deemed by the author to be the most important in terms of clinical burn care. Relevant topics include epidemiology, wound characterisation, critical care physiology, inhalation injury, infection, metabolism and nutrition, psychological considerations, pain management, rehabilitation, and burn reconstruction. Each selected article is mentioned briefly with editorial comment.