Risk factors in surgery

Bacterial Colonization on Endoscopic Materials and Surgical Field Without Infections After Transoral Endoscopic Thyroidectomy

INTRODUCTION

Our aim was to determine whether bacteria contamination occurred within the surgical field or on endoscopic equipment during surgery using the transoral endoscopic thyroidectomy vestibular approach (TOETVA).

MATERIALS AND METHODS

Participants were recruited from patients planned for TOETVA between May 2017 and December 2019. Bacterial samples were taken before and at the conclusion of the TOETVA procedure. The preoperative and postoperative samples were taken from the endoscopic materials and inferior oral vestibulum using a sterile flocked swab.

RESULTS

The study resulted in 480 samples (80 TOETVAs). No vestibular, port site, or neck infections occurred in any of the patients. Three (3.7%) out of 80 patients developed postoperative fever. Our results show different microbial communities during TOETVA. The most prevalent species detected were S treptococcus species. Multivariate logistic regression analyses revealed that the degree of contamination depended on the sampling site (inferior vestibulum > equipment) ( P =0.03). In addition, the abundance of bacteria was affected by operative time ( P =0.013). There were no significant differences observed in isolation frequencies of bacteria in malignancy ( P =0.34).

CONCLUSIONS

TOETVA surgery is categorized as a "clean-contaminated" operation. A swab identified the common colonizers of oral microbiota on the endoscopic equipment and within the surgical field.

Effects of Silybum marianum L. Seed Extracts on Multi Drug Resistant (MDR) Bacteria

Wound infections became a great challenge, especially after the emergence of bacterial resistance to commonly used antibiotics. Medicinal plants can be the source of alternative antibacterial agents effective against multi drug resistant (MDR) bacteria. This research aimed to evaluate the effectiveness of different Silybum marianum seed extracts in fighting MDR bacteria that infect wounds. First, thirty purified bacterial cultures obtained from superficial, infected wounds were subjected to antibiotic sensitivity tests. The selected MDR isolates were then used to test the antimicrobial effects of different S. marianum seed extracts. The most potent extract was evaluated for its impact on the ultrastructure of the cells of sensitive bacterial isolates using transmission electron microscopy (TEM). The bioactive ingredients of this extract were analyzed by means of gas chromatography-mass spectroscopy (GC-MS). Then, in-silico absorption, distribution, metabolism, excretion, and toxicity (ADMET) properties were predicted for the main components. The results indicated that four out of 30 bacterial isolates were considered MDR bacteria. Primary morphological features of colonies, secondary (automatic) identification using the Biomerieux Vitek 2 System, and 16S rRNA sequencing of the four isolates confirmed that they represent Staphylococcus aureus, Stenotrophomonas maltophilia, Klebsiella pneumoniae, and Escherichia coli. Among different extracts of S. marianum seeds, ethanol extract showed the strongest inhibitory effect on both Gram-positive and Gram-negative bacteria, with minimum inhibitory concentration (MIC) values between 9.375 and 1.172 mg/mL. However, at concentrations four times higher, this extract was unable to kill bacterial cells, indicating that it had a bacteriostatic effect on the tested MDR strains. TEM revealed denaturation and distorted cell ultrastructure in S. aureus and S. maltophilia after exposure to ethanol extract. In addition, GC-MS analysis of the ethanol extract identified nine compounds known to have important biological activities, and ADMET analysis showed good drug-likeness for two of these compounds. Consequently, S. marianum seeds could be a good source of alternative bacteriostatic agents effective against MDR bacterial strains that cause wound infections.

Maggot debridement therapy and complementary wound care: a case series from Nigeria

Objective:

Maggot debridement therapy (MDT) is an emerging procedure involving the application of sterile maggots of the Dipteran species (commonly Lucilia sericata) to effect debridement, disinfection and promote healing in wounds not responding to antimicrobial therapy. Data on MDT in sub-Saharan Africa (including Nigeria) are scarce. This study aimed to use medicinal grade maggots as a complementary method to debride hard-to-heal necrotic ulcers and thereby promote wound healing.

Method:

In this descriptive study, we reported on the first group of patients who had MDT at Aminu Kano Teaching Hospital (AKTH), a tertiary hospital in northern Nigeria. The first instar larvae of Lucilia sericata were applied using the confinement (free-range) maggot therapy dressing method under aseptic conditions.

Results:

Diabetic foot ulcer (DFU) grade III–IV constituted more than half of the wounds (53.3%), followed by necrotising fasciitis (30%), and post-traumatic wound infection (10%). Others (6.7%, included pyomyositis, surgical site infection and post traumatic wound infection). The median surface area of the wounds was 56cm 2 . Of the 30 patients, half (50%) had two MDT cycles with a median time of four days. Of the wounds, 22 (73%) were completely debrided using maggots alone while eight (27%) achieved complete debridement together with surgical debridement. Wound culture pre-MDT yielded bacterial growth for all the patients and Staphylococcus aureus was the predominant isolate in 17 wounds (56.7%) while Pseudomonas aeruginosa and Streptococcus pyogenes were predominant in five wounds (16.7%) each. Only four (13.3%) wound cultures yielded bacterial growth after MDT, all Staphylococcus aureus.

Conclusion:

A good prognosis was achieved post-MDT for various wounds. MDT effectively debrides and significantly disinfects wounds involving different anatomical sites, thus enhancing wound healing and recovery. MDT is recommended in such wounds.

Evaluation of antibiotic susceptibility in wound infections: A pilot study from Bangladesh

Introduction: Infections due to antibiotic resistant bacteria have increased alarmingly in both developed and developing countries. Unrestrained and rapidly spreading bacterial growth has turned the management of wound infections into a serious challenge. This study aimed to determine the prevalence of different bacterial pathogens and their antibiotic susceptibility in various types of wound infections. Methods:  A cross-sectional study was conducted to collect 105 wound swabs. All isolated bacteria were identified based on colony characteristics, gram stain and standard biochemical tests, and antibiotic susceptibility testing (AST) with the disc diffusion method. Descriptive statistics were used to present the study findings, and all analyses were performed using Stata Version 13. Results:  The rate of isolation of bacteria was 92.3%. Staphylococcus aureus was found to be the most frequent isolate (55.7%), followed by Escherichia coli (23.7%), Pseudomonas spp. (8.2%), and Streptococcus pyogenes (7.2%). Gram-positive bacteria were mostly (60%) found sensitive to vancomycin, azithromycin, gentamicin, imipenem, cefixime, and ceftriaxone in this study. Among the Gram-negative bacteria, Escherichia coli (>60%) showed sensitivity to cefixime, azithromycin, cefuroxime, ceftriaxone, cefotaxime, gentamycin, and ceftazidime. Conclusions: The diversity of isolated bacteria and their susceptibility patterns signify a need to implement a proper infection control strategy, which can be achieved by carrying out antibiotic sensitivity tests of the isolates.

Disinfection and healing effects of 222-nm UVC light on methicillin-resistant Staphylococcus aureus infection in mouse wounds

UVC radiation is known to be highly germicidal. However, exposure to 254-nm-UVC light causes DNA lesions such as cyclobutane pyrimidine dimers (CPD) in human cells, and can induce skin cancer after long-term repeated exposures. It has been reported that short wavelength UVC is absorbed by proteins in the membrane and cytosol, and fails to reach the nucleus of human cells. Hence, irradiation with 222-nm UVC might be an optimum combination of effective disinfection and biological safety to human cells. In this study, the biological effectiveness of 222-nm UVC was investigated using a mouse model of a skin wound infected with methicillin-resistant Staphylococcus aureus (MRSA). Irradiation with 222-nm UVC significantly reduced bacterial numbers on the skin surface compared with non-irradiated skin. Bacterial counts in wounds evaluated on days 3, 5, 8 and 12 after irradiation demonstrated that the bactericidal effect of 222-nm UVC was equal to or more effective than 254-nm UVC. Histological analysis revealed that migration of keratinocytes which is essential for the wound healing process was impaired in wounds irradiated with 254-nm UVC, but was unaffected in 222-nm UVC irradiated wounds. No CPD-expressing cells were detected in either epidermis or dermis of wounds irradiated with 222-nm UVC, whereas CPD-expressing cells were found in both epidermis and dermis irradiation with 254-nm UVC. These results suggest that 222-nm UVC light may be a safe and effective way to reduce the rate of surgical site and other wound infections.

Antibiotic susceptibility of wound isolates in plastic surgery patients at a tertiary care centre

Context:

Wound infection increases the hospital stay and adversely affects the recovery of patients. Culture and sensitivity of wound isolates help in proper diagnosis and management of these patients.

Aim:

To identify common bacteria causing wound infections and their antibiotic sensitivity pattern.

Study Design:

A cross-sectional study.

Place and Duration of Study:

Government Medical College and Hospital, Nagpur from October 2013 to October 2015.

Materials and Methods:

Pus samples were collected by doctors in ward using Sterile Swab Sticks. Bacterial isolates were identified and cultured, and antibiotic culture sensitivity tests were performed.

Statistical Analysis Used:

Chi-square test.

Results:

There were a total of 150 patients with infected wounds. Most common organism isolated was Pseudomonas followed by Klebsiella and Staphylococcus aureus. All of these organisms were resistant to most routine antibiotics.

Conclusion:

We suggest a multidisciplinary approach to wound management, rational drug use, routine microbiological surveillance of wounds and institution of hospital infection control policy.

Current microbial isolates from wound swabs, their culture and sensitivity pattern at the niger delta university teaching hospital, okolobiri, Nigeria

Background: Wound infections continue to be problematic in clinical practice where empiric treatment of infections is routine. Objectives: A retrospective cross-sectional study to determine the current causative organisms of wound infections and their antibiotic susceptibility patterns in the Niger Delta University Teaching Hospital (NDUTH), Okolobiri, Bayelsa State of Nigeria. Methods: Records of wound swabs collected from 101 patients with high suspicion of wound infection were analysed. Smears from the wound swabs were inoculated on appropriate media and cultured. Bacterial colonies were Gram stained and microscopically examined. Biochemical tests were done to identify pathogen species. The Kirby-Bauer disk diffusion method was used for antibiotic testing. Results: Prevalence of wound infection was 86.13% (CI: 79.41–92.85). Most bacteria were Gram negative bacilli with Pseudomonas aeruginosa being the most prevalent pathogen isolated. The bacterial isolates exhibited a high degree of resistance to the antibiotics tested (42.8% to 100% resistance). All isolates were resistant to cloxacillin. Age group and sex did not exert any effect on prevalence, aetiological agent or antimicrobial resistance pattern. Conclusion: We suggest a multidisciplinary approach to wound management, routine microbiological surveillance of wounds, rational drug use and the institution of strong infection control policies.

Prevalence of nosocomial wound infection among postoperative patients and antibiotics patterns at teaching hospital in Sudan

Background:

Postoperative nosocomial infections remain a major problem in health care facilities, resulting in extended length of stay, substantial morbidity and mortality, high excess of cost, and less frequent cause of death in the surgical patient.

Aims:

To determine the prevalence of aerobic nosocomial pathogens among patients with postoperative wound infections at Gadarif state which located in Eastern part of Sudan.

Materials and Methods:

109 wound swabs were collected from patients who had developed postoperative wound infection. Conventional technique for isolation of bacteria was applied with analytical profile index (API system) for identification to confirm primary and secondary isolates. Antibiotics susceptibility was applied for all isolated bacteria.

Results:

Aerobic bacterial isolates were S. aureus (n=55, 55.0%), P. mirabilis (n=35, 35.0%), E. coli (n=5, 5.0%), Ps. aeruginosa (n=3, 3.0%), and Pr. vulgaris (n=2, 2.0%). The prevalence rate of hospital acquired infection were 25.23%

Conclusion:

The highest prevalence rate of nosocomial postoperative wound infection, in Sudan was due to poor antibiotic selection, for prophylaxis during and after surgery and increased level of contamination in most part of the hospital.

Surgical-site infection surveillance in general surgery: a critical issue

This prospective study assessed the Surgical Site Infection (SSI) rates in General Surgery and the microorganisms isolated. From January 2000 to October 2000, 898 patients were enrolled and electively operated in a General Surgery Clinic in Athens, Greece. Pre-coded questionnaires were used. The diagnosis and surveillance of SSIs was made by the surgeon-investigator who interviewed the patients. Patients were monitored during hospitalization and post-discharge for 30 days. Overall, 402 patients underwent a clean and 496 patients underwent a clean-contaminated operation. A total of 17 SSIs (4.2%) were observed in clean and 64 SSIs (12.9%) in clean-contaminated operations. Microorganisms were isolated in 36 of 65 (55%) of cases that microbiological evaluation was performed. Staphylococcus aureus was the commonest microorganism isolated, followed by Escherichia coli and Pseudomonas aeruginosa. SSI rates were higher than expected and most SSIs, 43 of 81 (53.1%), were diagnosed post-operatively. Post-discharge surveillance of SSIs remains a critical issue. Health care professionals, especially surgeons, should participate in surveillance networks and be aware of the results so to take appropriate action.

The impact of perioperative blood transfusion on clinical outcomes in colorectal surgery

Colorectal cancer is the second-leading cause of cancer-related death in the US. The prognosis of advanced colorectal cancer remains poor in spite of the advances obtained in recent years with new therapeutic agents, new approaches in surgical procedures and new diagnostic methods. Currently, colorectal cancer is the second most common cancer in Europe both in terms of incidence and mortality. Approximately 90% of all cancer deaths arise from the metastatic dissemination of primary tumors. It is a matter of vital importance whether perioperative blood transfusion promotes tumor recurrence and morbidity. This paper reviews the relevant medical literature published in English language on the theoretical background, methodological problems, results, as well as the possible clinical impact of blood transfusions in colorectal surgery with well-controlled trials. Searches were last update August 2007.

Surgical site infections after thyroidectomy

BACKGROUND

The history of thyroid surgery starts with Billroth, Kocher, and Halsted, who developed techniques for thyroidectomy between 1873 and 1910. Before 1950, the operative mortality rate approached 50%. The advent of general anesthesia and antisepsis and the development of fine hemostatic instruments rendered thyroid surgery safer, but the potential persists for life-threatening complications. This study was designed to identify specific risk factors for the development of surgical site infections (SSIs); to define high-risk patients; to determine the causative organisms; to illustrate the clinical presentation, treatment, and outcome; and to establish management guidelines.

METHODS

A prospective analysis was carried out of complications affecting 241 consecutive patients (mean age 65+/-19 years; 76% female) undergoing cervical exploration for thyroid disease from 2000 to 2005, with particular attention to infection, and the pertinent literature was reviewed.

RESULTS

Surgical site infections (SSI) affected 2% of patients. The risk of infection depended mainly on the quality of pre-operative and post-operative care and on whether there was a break in sterile technique. The use of drains and pre-operative antibiotics did not affect the incidence of SSI. No pre-operative factor foreshadowed this complication, and the definition of a high-risk population remains obscure. Surgical site infections lengthened the hospital stay.

CONCLUSIONS

Effort should be made to improve sterile technique. Appropriate antibiotic coverage is indicated when infection develops post-operatively. The most important element in the management of SSI is adequate drainage of the incision once infection develops.

Risk factors for surgical infections

BACKGROUND

Many risk factors for postoperative infections have been identified that can be used individually or in combination as scoring indices.

METHODS

Infection risk scores can be applied in clinical practice to identify high-risk surgical patients, to indicate the need to implement risk-reduction strategies, and to stratify risk for comparison of outcome among different patient series.

RESULTS

In the hierarchy of patient-related risk factors, serum albumin concentration and advanced age rank at the top of the list. Among the treatment-related factors, the quality of the surgical technique is a most important determinant, although most surgical site infections are attributable to patient-related risk factors rather than to flawed surgical care. Scoring systems can identify the patients at highest risk, thus prompting the implementation of therapy to improve modifiable conditions, but most clinicians outside the academic and research setting do not use them. Risk assessment also can be performed by expert clinical judgment. Discussion with the patient and informed consent are essential.

CONCLUSIONS

Carefully collected scores of patient risk factors may be valuable to document the relations between the risk and the outcome of surgery. Ideally, each institution should select a validated scoring system to audit postoperative infectious morbidity and surgical performance in the various specialties.

Postoperative Fever

BACKGROUND

Fever is common in surgical patients. The list of potential causes is long and includes many noninfective etiologies.

CAUSES

Only about 40% of fever episodes in hospitalized patients are caused by infection. Any fever in a surgical patient is a cause for concern. New or continuing fever more than three days after surgery should raise a strong suspicion of persistent illness or a new complication. On rare occasions, these fevers can be attributed to potentially life-threatening occult infections, including acute cholecystitis, antibiotic-related pseudomembranous colitis, systemic candidiasis, or transfusion-related cytomegalovirus disease. A change in the microbiology of postoperative infections has also been noticed, characterized by a greater incidence of infections caused by methicillin-resistant Staphylococcus aureus, by polymicrobial flora, and by fungi.

TREATMENT

Control of nosocomial infections has become more challenging recently because of widespread bacterial resistance to antibiotics and to more frequent surgical indications in elderly patients at higher risk. Early recognition and appropriate treatment of these infections relieves anxiety, reduces hospital costs, and increases patient survival rates.

CONCLUSIONS

The workup and therapy for the individual patient may differ, depending on the underlying disease and clinical appearance and the clinician's suspicion for infection. Subsequent testing should be based on the clinical findings. Perhaps more money is wasted in the evaluation of early postoperative fever than on any other aspect of postoperative care.

Prospective Study of Infection Risk Factors in 988 Lung Resections

PURPOSE

To evaluate the incidence of surgical site infections (SSI), as related to risk factors, in patients undergoing lung resections (LR).

METHODS

We evaluated 988 consecutive patients prospectively who underwent LR between 1996 and 2005 at the Center for Thoracic Surgery of the University of Insubria, Varese, Italy. Patients were divided into four groups: Pneumonectomy (n=104), lobectomy/bi-lobectomy (n=438), wedge resection by thoracotomy (n=155), and wedge resection by video-thoracoscopy (VATS) (n=291). The recorded risk factors for SSI were hemoglobin concentration, serum albumin concentration, lymphocyte count, percentage of predicted forced expiratory volume in 1 sec (FEV1), duration of surgery, blood transfusion, age>70 years, and comorbidity. The postoperative SSIs (superficial and deep incisional SSI, pneumonia, empyema) were recorded in they occurred within 30 days, and the final outcome was recorded.

RESULTS

Postoperative infections were found in 141 patients (14.3%) and included 166 thoracic infections, among them 32 incisional SSIs (3.2%), 103 cases of pneumonia (10.4%); and 24 empyemas (2.4%). The overall incidence of SSI was significantly lower in patients having wedge resections by VATS (5.5%) than in the other three groups (17.9%) (p<0.001). The overall mortality rate was 1.2% (12/988), of which six deaths (0.6%) were caused by complications of infection. The infection rate correlated with duration of surgery>180 min, age>70 years, serum albumin<3.5 g/dL, and the presence of any comorbidity. Moreover, 18% of patients with FEV1>70% had postoperative pneumonia, a significant increase (p<0.01) compared with patients with FEV1>or=70%.

CONCLUSIONS

In this prospective study, the SSI rate after LR was 14.3%, and the 30-day operative mortality rate was 1.2%, with most of the deaths caused by pneumonia. After VATS LR procedures, the incidence of SSI was lower at 5.5%. Finally, SSI correlated with the duration of surgery, serum albumin, concurrent comorbidity, age, and FEV1.