Prevalence of Multidrug-Resistant Organisms in Patients Undergoing Free Flap Reconstruction

Antibiotic Resistance and Surgical Site Infections in Free Flap Reconstruction for Head and Neck Cancer: A Retrospective Analysis From a Lower-Middle-Income Country

OBJECTIVE

This study aimed to analyze the frequency of infection and its causative organisms, with their antibiotic susceptibility pattern, in patients who underwent free flap reconstructive surgery for head and neck cancers.

METHODOLOGY

This hospital record-based cross-sectional study was conducted at Aga Khan University Hospital in Karachi, Pakistan, involving 92 patients who underwent free flap reconstruction between January 1, 2023, and December 31, 2023. Data, including demographic information, surgical specifics, and microbial profiles, were collected from patient records, with a focus on postoperative wound infections after obtaining approval. Data analysis was done using IBM SPSS Statistics for Windows, Version 23 (Released 2015; IBM Corp., Armonk, New York, United States).

RESULTS

Among 92 patients, 11 (11.9%) developed surgical site infections (SSIs). Male gender and age between 41 and 60 years were significantly associated with the occurrence of SSIs (p < 0.001). There was no significant relationship between age, American Society of Anesthesiologists (ASA) score, comorbidities, and flap types. Gram-negative bacteria, particularly Pseudomonas aeruginosa, dominated isolates. Early-onset SSIs were primarily associated with P. aeruginosa, whereas late-onset infections showed a broader spectrum of Gram-negative pathogens, including Enterobacter and Klebsiella species, suggesting temporal variations in microbial colonization. Multidrug-resistant organisms (MDROs) were identified in 66.6% of Gram-negative and all Gram-positive isolates, with extended drug resistance (XDRO) observed in select Gram-negative cases. P. aeruginosa was the most common Gram-negative isolate, while Staphylococcus aureus predominated among Gram-positive bacteria.

CONCLUSION

SSI was noted in 11.9% of the free flap population. Tailored antibiotic prophylaxis is crucial due to significant antimicrobial resistance in Gram-negative bacteria like P. aeruginosa and Enterobacter. Vigilant postoperative monitoring is essential given consistent pathogenic profiles in early- and late-onset infections, urging careful antibiotic stewardship in managing these infections effectively.

Red and blue LED light increases the survival rate of random skin flaps in rats after MRSA infection

Skin flap transplantation is a conventional wound repair method in plastic and reconstructive surgery, but infection and ischemia are common complications. Photobiomodulation (PBM) therapy has shown promise for various medical problems, including wound repair processes, due to its capability to accelerate angiogenesis and relieve inflammation. This study investigated the effect of red and blue light on the survival of random skin flaps in methicillin-resistant Staphylococcus aureus (MRSA)-infected Sprague Dawley (SD) rats. Forty male SD rats were divided into control and light-emitting diode-red and blue light-treated (LED-RBL) groups at a ratio of 1:1 and a McFarland flap procedure was performed, which was subsequently infected with MRSA strains. After 7 days, the appearance and survival of the flaps were evaluated. The microvascular density was determined by hematoxylin and eosin (HE) staining. The expression levels of vascular endothelial growth factor (VEGF), hypoxia inducible factor 1α (HIF-1α), phosphatidylinositol 3-kinase (PI3K), and protein kinase B (normally expressed as AKT) were detected by immunohistochemistry. The flap survival rate and microvascular density in the LED-RBL group were significantly higher than those in the control group (P < 0.05). In addition, the VEGF, HIF1-α, PI3K, and AKT levels were significantly higher in the LED-RBL group compared to the control group (P < 0.05). Red and blue light increased the survival area of the infected flap in rats by promoting angiogenesis, relieving oxidative stress, and reducing bacterial loads, indicating that PBM therapy is a convenient, simple, analgesic, and safe treatment intervention in promoting the survival rate of transplanted flaps after wound repair surgery.

Retrospective analysis of drug resistance characteristics and infection related risk factors of multidrug-resistant organisms (MDROs) isolated from the orthopedics department of a tertiary hospital

Patients infected with multidrug-resistant organisms (MDROs) are known to exhibit longer hospital stays and a significantly poorer prognosis. We performed a 6-year retrospective analysis of nosocomial infections reported in the orthopedics department of our institution, to gain valuable insights into antibiotic sensitivity and infectious characteristics of MDROs, in order to deduce effective measures to control the occurrence of multidrug-resistant infections in clinical practice. A retrospective, single center surveillance study (January 2012-December 2017) was performed on the nosocomial infections recorded in the department of orthopedics. A nosocomial infection is defined as one that develops when a patient is residing in a hospital but was not present at the time of admission. All relevant data, including basic patient information, cultivated bacterial strains, and antimicrobial resistance, was obtained from the hospital information system. A total of 1392 strains of pathogenic bacteria were isolated; 358 belonged to MDROs (detection rate = 25.7%). All the isolated strains of MDROs were mostly from secretions (52.2%). The number of cases infected with MDROs were 144 (40.2%) and 129 (36.0%) in the trauma and spinal wards, respectively. MRSA showed high resistance to β lactam antibiotics, but was sensitive to quinolone antibiotics, linezolid and cotrimoxazole. ESBL-positive strains showed more sensitivity to carbapenem antibiotics (resistance rate < 10%). MDR nonfermenters showed high resistance to most antibiotics. Logistic multivariate analysis revealed age, open injury, and central nervous system injury as independent risk factors for multidrug resistant infections. A high antibiotic resistance rate and an increasing prevalence of infections with MDROs was identified in the orthopedics department. Patients with open injury, central nervous system injury and those aged ≥ 60 years, were more prone to multidrug-resistant infections. Clinicians should pay more attention to such patients in order to actively prevent and control the occurrence of infections caused by MDROs.