Multivariate analysis of risk factors for wound infection in head and neck squamous cell carcinoma surgery with opening of mucosa. Study of 260 surgical procedures

Molecular Genetic Analysis of Perioperative Colonization by Infection-Related Microorganisms in Patients Receiving Intraoral Microvascular Grafts

Background/Objectives: In oral and maxillofacial surgery, the reconstruction of defects often involves the transfer of skin tissue into the oral cavity utilizing microvascular grafts. This study investigates postoperative changes in microbial colonization following intraoral microvascular transplantation, as well as potential influencing factors. Methods: In 37 patients undergoing intraoral reconstructions, pre- and postoperative swabs were taken from the donor and recipient regions to quantify the seven selected marker bacteria using TaqMan PCRs. Patient-specific factors and clinical data were also recorded. Results: The infection-associated Acinetobacter baumannii tended to decrease postoperatively, while the infectious pathogens Pseudomonas aeruginosa, Enterococcus faecalis and the family of Enterobacteriaceae showed a postoperative increase without being directly associated with a clinical infection. Streptococcus mitis showed a significant postoperative decrease on buccal mucosa and increase on the graft surface (oral dysbiosis) and was significantly reduced or displaced by other bacteria (e.g., Mycoplasma salivarium, positive selection) when treated with ampicillin/sulbactam. Conclusions: The cutaneous microbiome of the graft adapts to the local intraoral environment. Postoperative shifts in oral bacterial colonization and an increase in infection-relevant bacteria were observed. These perioperative changes in colonization are also influenced by the administration of ampicillin/sulbactam. Consequently, single doses of antibiotics appear to be more beneficial compared to longer-term preventive use.

Number of Bacteria in Saliva in the Perioperative Period and Factors Associated with Increased Numbers

Perioperative oral management is performed to prevent postoperative complications, but its indication and management method are unclear. This study aimed to investigate salivary bacterial counts pre-and postoperatively, and factors related to increased bacterial count postoperatively. We included 121 patients who underwent surgery under general anesthesia and perioperative oral management. The bacterial count in saliva was determined preoperatively, and first and seventh days postoperatively using the dielectrophoresis and impedance measurement methods. The relationships between salivary bacterial count and various variables were analyzed using one-way analysis of variance, Spearman’s rank correlation coefficient, and multiple regression analysis. The salivary bacterial count increased significantly on the first day postoperatively but decreased on the seventh day. Multivariate analysis showed that age (p = 0.004, standardized coefficient β = 0.283) and xerostomia (p = 0.034, standardized coefficient β = 0.192) were significantly correlated with increased salivary bacterial count preoperatively. Salivary bacterial count on the day after surgery was significantly increased in patients with a large number of bacterial counts on the day before surgery after preoperative oral care (p = 0.007, standardized coefficient β = 0.241) and postoperative fasting (p = 0.001, standardized coefficient β = −0.329). Establishing good oral hygiene before surgery and decreasing salivary bacterial count are necessary in patients with a high risk of postoperative surgical site infection or pneumonia, especially in older adults or postoperative fasting.

A health technology assessment between two pharmacological therapies through Six Sigma: the case study of bone cancer

Purpose

Head and neck cancers are multi-factorial diseases that can affect many sides of people's life and are due to a lot of risk factors. According to their characteristics, the treatment can be surgical, use of radiation or chemotherapy. The use of a surgical treatment can lead to surgical infections that are a main theme in medicine. At the University hospital of Naples “Federico II”, two antibiotics were employed to tackle the issue of the infections and they are compared in this paper to find which one implies the lowest length of hospital stay (LOS) and the reduction of infections.

Design/methodology/approach

The Six Sigma methodology and its problem-solving strategy DMAIC (define, measure, analyse, improve, control), already employed in the healthcare sector, were used as a tool of a health technology assessment between two drugs. In this paper the DMAIC roadmap is used to compare the Ceftriaxone (administered to a group of 48 patients) and the association of Cefazolin plus Clindamycin (administered to a group of 45 patients).

Findings

The results show that the LOS of patients treated with Ceftriaxone is lower than those who were treated with the association of Cefazolin plus Clindamycin, the difference is about 41%. Moreover, a lower number of complications and infections was found in patients who received Ceftriaxone. Finally, a greater number of antibiotic shifts was needed by patients treated with Cefazolin plus Clindamycin.

Research limitations/implications

While the paper enhances clearly the advantages for patients' outcomes regarding the LOS and the number of complications, it did not analyse the costs of the two antibiotics.

Practical implications

Employing the Ceftriaxone would allow the Department of Maxillofacial Surgery to obtain lower LOS and a limited number of complications/infections for recovered patients, consequently reducing the hospitalization costs.

Originality/value

There is a double value in this paper: first of all, the comparison between the two antibiotics gives an answer to one of the main issues in medicine that is the reduction of hospital-acquired infections; secondly, the Six Sigma through its DMAIC cycle can be employed also to compare two biomedical technologies as a tool of health technology assessment studies.

The effect of tooth brushing, irrigation, and topical tetracycline administration on the reduction of oral bacteria in mechanically ventilated patients: a preliminary study

Background

One of the main causes of ventilator-associated pneumonia (VAP) is thought to be aspiration of oropharyngeal fluid containing pathogenic microorganisms. The aim of this study was to examine the effects of various oral care methods on the reduction of oral bacteria during intubation.

Methods

First, the effect of mechanical oral cleaning was investigated. The bacterial count on the tongue and in the oropharyngeal fluid was measured after tooth brushing, irrigation, and three hours after irrigation in mechanically ventilated patients at the intensive care unit (ICU).

Next, the efficacy of topical administration of tetracycline and povidone iodine on the inhibition of bacterial growth on the tongue and in the oropharyngeal fluid was examined in oral cancer patients during neck dissection.

Results

The number of bacteria in the oropharyngeal fluid was approximately 10⁵–10⁶ cfu/mL before surgery, but increased to 10⁸ cfu/mL after intubation. Oral care with tooth brushing and mucosal cleaning did not reduce oral bacteria, while irrigation of the oral cavity and oropharynx significantly decreased it to a level of 10⁵ cfu/mL (p < 0.001). However, oral bacteria increased again to almost 10⁸ cfu/mL within three hours of irrigation.

Oral bacteria did not decrease by topical povidone iodine application. In contrast, 30 min after topical administration of tetracycline, the number of oral bacteria decreased to 10⁵ cfu/mL, and remained under 10⁶ cfu/mL throughout the entire experimental period of 150 min.

Conclusions

While the present studies are only preliminary, these results indicate that irrigation of the oral cavity and oropharynx followed by topical antibiotic administration may reduce oral bacteria in mechanically ventilated patients.

Trial registration

UMIN000018318, 1 August 2015.

The time course and microbiology of surgical site infections after head and neck free flap surgery

OBJECTIVES/HYPOTHESIS

Determine the time of onset and microbiology of surgical site infections (SSIs) following head and neck free flap reconstructive surgeries.

STUDY DESIGN

Retrospective cohort study.

METHODS

All 504 free flap surgical cases (484 patients) performed April 1, 2009 to September 30, 2013 were reviewed; SSIs occurring ≤30 days postoperatively were evaluated. Admission screening for methicillin-resistant Staphylococcus aureus (MRSA) colonization was performed on all patients.

RESULTS

Flap-recipient site infections (flap SSIs) occurred in 67 cases (13.3%), one-third week 1 postoperatively, one-third week 2, one-third days 15 to 30; 45% occurred after hospital discharge. Wound cultures were polymicrobial, but 25% grew only normal oral flora, whereas 75% grew pathogens not part of normal oral flora, such as gram-negative bacilli (44% of cases), MRSA (20%), and methicillin-sensitive S aureus (MSSA) (16%). The frequency of these pathogens did not vary significantly by the time of SSI onset. In 67%, cultures included at least one pathogen resistant to the prophylactic antibiotic used. Clindamycin prophylaxis was a significant risk factor for flap SSI and for early partial or complete flap loss from infection. Donor SSIs occurred in 22 cases (4.4%), 95% >1 week postoperatively, and MRSA or MSSA were the primary pathogens in 89%. Of the 25 patients colonized with MRSA on admission, 40% developed a flap or donor SSI, a rate significantly higher than in non-colonized patients.

CONCLUSIONS

Gram-negative bacilli, MRSA, and MSSA were significant SSI pathogens, and late onset of infection was common. Better screening, decolonization, and prophylaxis may reduce SSI rates.

LEVEL OF EVIDENCE

2b

[Post-laryngectomy pharyngocutaneous fistula--a continuing clinical problem]

BACKGROUND

Pharyngocutaneous fistula following laryngectomy is a serious complication, and its incidence varies from 4% to 65%. The study's objective was to determine the incidence of post laryngectomy fistulas in patients operated in our department to establish whether specific factors predispose to fistula formation.

METHODS

A retrospective study was performed in 573 patients who underwent laryngectomy.

RESULTS

Between 1989 and 1999, 835 cases of laryngeal carcinoma were diagnosed, 690 were treated surgically, 573 of them underwent laryngectomy in our department. Of these patients, 545 (95,1%) had total laryngectomy, while 28 (4,9%) partial laryngectomy. In 538 cases the laryngectomy was combined with radical or functional neck dissection. The presence of early postoperative fistula was established in 65 of the 573 patients (11,3%). Our study could not verify reports that any specific factors were significantly related to fistula formation, the only factors that did show statistical significance were the preoperative patient's general health status and the kind of postoperative antibiotic therapy.

CONCLUSIONS

On the base of literature review, the authors compare results obtained in the last decade of the 20 century with results obtained earlier. Although the incidence of post-laryngectomy pharyngocutaneous fistulas decreased in comparison with the fistula rate observed earlier, the problem is still unresolved, and the fistulae remain a serious complication of larynx oncology surgery.