Journal of Infectious Diseases & Preventive Medicine
Open Access

Surgical Anti-Microbial Prophylaxis and Incidence of Surgical Site Infections: AHospital Based Prospective Study

Author info »

Introduction

Health Care-Associated Infections (HAIs) remain as an important public health concern. Amongst the prominent HAIs, Surgical Site Infections (SSIs) contributing to substantial rate of mortality, significant morbidity, considerable prolongation in length of hospitalization and added treatment expenses [1].

Wound infections are the commonest hospital-acquired infections in surgical patients. They result in increased antibiotic usage, increased costs and prolonged hospitalization [2]. Appropriate antibiotic prophylaxis can reduce the risk of postoperative wound infections, but additional antibiotic use also increases the selective pressure favoring the emergence of antimicrobial resistance [3].

Surgical antibiotic prophylaxis is defined as the use of antibiotics to prevent infections at the surgical site. It must be clearly distinguished from pre-emptive use of antibiotics to treat early infection, for example perforated appendix, hernia etc. even though infection may not be clinically apparent.

The original surgical antibiotic prophylaxis experiments were performed 40 years ago in pigs. The results concluded that 'the most effective period for prophylaxis begins the moment bacteria gain access to the tissues and is over in three hours. Since then there have been many studies in animal models and in humans undergoing surgery. This has resulted in the principles of antibiotic prophylaxis becoming an accepted part of surgical practice [4].

Approximately 30%-50% of antibiotic use in hospital practice is now for surgical prophylaxis. However, between 30% and 70% of this prophylaxis is inappropriate. Most commonly, the antibiotic is either given at the wrong time or continued for too long. Controversy remains as to duration of prophylaxis and also as to which specific surgical procedures should receive prophylaxis [5].

SSI classification

According to the Centers for Disease Control and Prevention (CDC)’s guideline, SSIs are separated into three types, depending on the depth of infection penetration into the wound [6-8].

By these criteria, SSIs are classified as being. Either incisional or organ/space. Incisional SSIs are further divided into those involving only skin and subcutaneous tissue (superficial incisional SSI) and those involving deeper soft tissues of the incision (deep incisional SSI). Organ/space SSIs involve any part of the anatomy (e.g., organ or space) other than incised body wall layers that was opened or manipulated during an operation (Figures 1 and 2).

Figure 1: Types of SSI relating to infection penetration depth [9].

Figure 2: Classification of SSI [9,10].

Superficial incisional infection: Superficial incision infection defined as a surgical site infection that occurs within 30 days of surgery and involves only the skin or subcutaneous tissue of the incision, and meets at least one of the following criteria:

Purulent drainage from the incision.

Organisms isolated from an aseptically obtained culture of fluid or tissue from the incision.

At least one of the following signs or symptoms of infection-pain or tenderness, localised swelling, redness or heat.

Deep incisional surgical site infections: Deep incisional surgical site infections must meet the following three criteria: it occurs within 30 days of procedure (or one year in the case of implants); it is related to the procedure and this involves deep soft tissues, such as the fascia and muscles. Besides deep incisional surgical site infections may involve any of the following criteria:

Purulent drainage from the incision but not from the organ/ space of the surgical site.

A deep incision spontaneously dehisces or is deliberately opened by a surgeon when the patient has at least one of the following signs or symptoms-fever (>38°C), localized pain or tendernessunless the culture is negative.

An abscess or other evidence of infection involving the incision is found on direct examination or by histopathologic or radiological examination.

Diagnosis of a deep incisional SSI by a surgeon or attending physician.

Organ/Space SSI: In Organ/Space SSI occurs within 30 days after the operation if no implant is left in place or within 1.

Sources of infection

Sources of infection are widely varied. Infections may be primarily acquired from a community or endogenous source. Sources of infection may be hospital acquired or community acquired [11].

Endogenous factors or sources of bacteria:

Co-existing infection in other site of body

Skin

Bowel

Nature and site of operation (Clean, clean-contaminated, contaminated and dirty)

Exogenous factors or sources of bacteria:

Operating team-related-Comportment; Use of impermeable drapes and gowns;

Surgical scrub.

Operating room related-Traffic control; Cleaning; Air

Surgical wound infections are also strongly influenced by the risk factors related to patients-extremities of age, obesity, diabetes mellitus, smoking habit, Coexisting infection at other site etc.

Etiological agents

Many different bacteria, viruses, fungi and parasites may cause wound infections. Infections may be caused by a microorganism acquired from another person in the hospital (cross-infection) or may be caused by the patient’s own flora (endogenous infection). Some organisms may be acquired from an inanimate object or substances recently contaminated from another human source (environmental infection.

According to data from the national nosocomial infection surveillance system, the distribution of pathogens isolated from SSIs has not changed markedly during the last decade where Staphylococcus aureus, Coagulase-negative Staphylococci (CoNS),Enterococcus spp. And Escherichia coli remain the most frequently isolated pathogens [12].

Furthermore, nosocomial blood stream infections are usually caused by Gram-positive organisms including Coagulase negative Staphylococcus, S. aureus, Enterococci [13,14] and these microorganisms nearly always represent true bacteremia such as E. coli and other members of the Enterobacteriaceae, Pseudomonas aeruginosa, and Streptococcus pyogenes (Table 1) [14].

Prophylactic antibiotics: Prophylactic antibiotics decrease the risk of infection and represents important components of most favourable management of the surgical patient [15-21]. So errors in antimicrobial prophylaxis for surgical patients remain one of the most frequent types of medication errors in hospitals. The antibiotics selected for prophylaxis must cover the expected pathogens responsible for infection, should achieve adequate tissue levels during operation, cause minimal side effects and be relatively inexpensive [22].

Table 1: Risk factors.

A prophylactic antibiotic should be used where evidence of benefit exists. Choice of antibiotic depend on type of surgery, area of surgery, etiological agents mostly responsible for wound infections, patient’s physical status and wound class. According to the Antibiotic prophylaxis in surgery (A national clinical guideline) Scottish Intercollegiate Guidelines Network, Prophylaxis antibiotics are highly recommended for Appendicectomy, Colorectal surgery, Caesarean section, Transurethral resection of the prostate, and Arthroplasty surgery to reduces major morbidity, hospital costs [21]. In gynaecology. For prophylaxis, first generation cephalosporins are suitable choices to prevent postoperative sepsis, by E. coli, S. aureus and B. fragilis [23-25]. Many systematic studies were carried out to measure the relative efficacy of antimicrobial prophylaxis for the prevention of postoperative wound infection in different surgery.

Study criteria

Inclusion criteria:

Patient undergone surgery.

Patient of age above 18 years.

Patient who are willing to participate in the study.

Exclusion criteria:

Surgery where there is no need for prophylactic antibiotics.

The post-operative follow up was missed.

Pregnant and nursing mother.

Psychiatric patient.

Materials and Methods

A descriptive, prospective and hospital-based study was conducted in Jayanagar General Hospital, Bangalore in department of general surgery over a period of 6 months, after obtaining the clearance and approval from the Institutional Ethics Committee.

Statistical analysis

Descriptive statistics is done by measuring different proportions. Statistical measurement was done in SPSS trial version 24.0. Graphical representation was done in using Microsoft Excel.

Results

Patient demographics

A total of 180 patients were enrolled in the study,who satisfies inclusion and exclusion criteria, 88 (48.89%) were males and 92 (51.11%) were females. majority of patient were found under the age group of 41-50 years 59(32.78%) followed by 52(28.89%) patients under 31-40 years; 35(19.44%) patient under 21-30 years, 22(12.22%) patients under 0-20(18-20) years, 6(3.33%) patient age under 51-60 years and patient over 60 years, 6(3.33%).among them 56% of patient having no formal education, 16.11% have primary education followed by 13.88% secondary, 11.11% PUC education and 2.77 having degrees and 56.12% patient enroll any of occupation was 88.34% (Table 2).

Table 2: Patient characteristics.

Age distribution and SSI

Increasing age increases the insidance of surgical site infections. Out of these, age(51-60) is 3 out of 6 is 50%, >60 age is 2 out of 6 is 33.33% and age (41-50) is 8% followed by 4 out of 59 patient, 5 out of 52 patient,2 out of 22, 3 out of 35 (Figure 3).

Figure 3: Age distribution with SSI.

Presence of risk factor associated with infection

Among 180 patients in this study, 93 patient (51.66%) is having previous risk factor, Among them 40.86% were smokers,27.96% are anemic, followed by patient associated with DM,DM/HTN, obesity, blood loss and other infection. Coexisting infected patient is 2 among 3 which is 66.67% (Table 3 and Figure 4).

Figure 4: Risk distribution.

Table 3: Presence of risk factor.

Duration of operation to discharge depending upon present of SSI

The length of hospital stay after surgery had increased more than 3 times for the patient with SSI than patient who did not have SSI. It imposes increased cost burden to the patient (Table 4 and Figure 5).

Figure 5: Patients with and without SSI.

Table 4: Duration of operation.

Incidence of SSI and gender

Among 180 patient enrolled in the study, out of 88 male patient 10 developed infection.i.e., 5.55% of total patient. Whereas among 92 female patient 9 developed infection i.e., 5% of total patient enrolled in the study. This suggested that both sex have equal chances of developing infection (Table 5 and Figure 6).

Figure 6: Patients statistics.

Table 5: Total number of patients.

Table 6: Organisms isolated.

Distribution of bacteria associated with infection

Out of 19 patient with SSI patient undergone for culture tests. 10 patient (52.63%) infected patient have staphylococcus infection, 3(15.79%) are having Pseudomonous aerogenosa followed by 2(10.53%) with E. coli, 2(10.53%) Enterococcus, 2(10.53%) Klebsellia pneumonia from culture and the incidence of isolated organism after SSI in different population. Staphylococcus was more in female rather than male and the Pseudomonous, E.coli, Klebesilla, Enterococcus is having similar incidences in male and female that pathogens showed differences for sensitive Staphylococcus aureus and Pseudomonas aeruginosa, which were more frequent in women than male (Table 6 and Figure 7).

Figure 7: Classification of bacteria.

Wound classification

102(56.67%) were having clean-contaminated wound, 56(31.11%) were having clean wound followed by 20(11.11%) were having contaminated and 1.11% having dirty wound (Tables 7 and 8) (Figure 8).

Figure 8: Wound classification.

Table 7: Wound surgery.