European Journal of Cardiovascular Medicine

Surgical infections—especially surgical site infections (SSIs)—have posed a persistent challenge in the field of surgery and trauma care for thousands of years, with evidence of such infections dating back 4000–5000 years¹. The Centers for Disease Control and Prevention (CDC) defines an SSI as “an infection occurring after surgery in the part of the body where the surgery took place.” SSIs account for approximately 15% of all hospital-acquired infections and represent the most prevalent nosocomial infection among surgical patients².

These infections frequently complicate postoperative recovery and are identified as the third most common type of hospital-acquired infection, comprising 14–16% of such cases. In India, research indicates that SSIs result in extended stays in both intensive care units and general wards. They also necessitate repeated antibiotic therapies, increasing the economic burden on patients—by around 3.8% for mild cases, 14.7% for moderate, and up to 29.4% for severe infections. On average, patients with SSIs incur treatment costs of roughly ₹29,000 compared to ₹16,000 for those without infections. Furthermore, the mortality rate is significantly higher among those with infections (12.8–19.9%) compared to uninfected patients (1.1–3.8%)³.

A study by Davidson et al., involving 1,000 general surgical procedures, highlighted that bacterial presence in the surgical incision at the time of wound closure plays a key role in the development of postoperative wound infections. Although the exact pathways through which bacteria access the wound remain unclear, their presence during closure is a critical determinant of infection⁴.

The practice of antibiotic prophylaxis in surgery emerged shortly after the introduction of penicillin, aimed at reducing the incidence of surgical wound infections. Before the 1960s, antibiotics were commonly administered postoperatively, a method now understood to be largely ineffective. Furthermore, antibiotics were often reserved for patients considered high-risk, which paradoxically resulted in a higher infection rate among these individuals than among those who received no prophylaxis⁵.

Subsequent animal and human studies confirmed that administering antibiotics before the onset of wound contamination—i.e., preoperatively—markedly reduces the risk of SSIs⁶. Effective prevention requires maintaining high concentrations of suitable antibiotics in the tissues throughout the operation to eliminate bacteria introduced during surgery.

Polk emphasized that the effectiveness of antibiotic prophylaxis hinges on achieving elevated tissue drug levels, which is more efficiently accomplished through intra-incisional injection prior to surgery than by relying solely on systemic (blood or serum) levels⁷.

Research has demonstrated that pre-incisional antibiotic administration produces exceptionally high local drug concentrations at the surgical site throughout the operation, effectively neutralizing any susceptible bacteria⁸. This method offers two key advantages:

1. Sustained high antibiotic levels at the wound site to prevent local infection.
2. Adequate systemic levels to reduce the risk of systemic sepsis.

Regardless of their protein-binding characteristics, antibiotics applied directly to the wound are rapidly absorbed from the surgical surface. Importantly, the antibiotic concentration in wound fluid—rather than in the bloodstream—is the primary factor influencing the success of prophylaxis against SSIs⁹⁻¹⁰.

Objective: To study the comparative efficacy of pre-operative prophylactic intravenous antibiotics with combined intravenous and intra-incisional antibiotic administration in reducing surgical site infection.

A prospective cohort study was conducted in the Department of General Surgery at the Major Operation Theatre of K.R. Hospital, affiliated with Mysore Medical College and Research Institute (MMCRI), Mysore. The study spanned 18 months, from December 2023 to May 2025, and included patients undergoing elective general surgical procedures. Ethical approval was obtained, and all participants provided informed written consent before enrollment.

Eighty patients aged between 25 and 65 years who were scheduled for clean or clean-contaminated surgeries lasting less than two hours were recruited based on inclusion and exclusion criteria. Patients with diabetes, immunocompromised states, pregnancy, bleeding disorders, those on steroid or anticoagulant therapy, or with known hypersensitivity to antibiotics were excluded. Participants were divided into two groups of 40 each. Group allocation followed a systematic approach, with the first case selected by lottery and subsequent cases assigned alternately.

Group A received a single prophylactic dose of 1 gram of intravenous Ceftriaxone 20 minutes before the skin incision during anaesthesia induction. Group B received the same intravenous dose along with intra-incisional infiltration of 1 gram of Ceftriaxone diluted in 10 ml distilled water. The solution was uniformly infiltrated into the subcutaneous tissue around the planned incision site using a 21-gauge syringe. All patients underwent preoperative antibiotic sensitivity testing and standard preparation, including shaving and antiseptic scrubbing with povidone-iodine followed by methylated spirit.

Postoperative wound care involved occlusive dressings, removed for the first inspection after 72 hours. Suspected surgical site infections (SSIs) were evaluated using wound swabs sent for culture and antibiotic susceptibility testing in the Department of Microbiology. Wounds were managed daily with povidone-iodine dressings, and complications were documented following CDC guidelines for SSIs. All clinical and microbiological data were recorded using a standardized case proforma. Data were entered into Microsoft Excel and analyzed using SPSS version 20. Categorical variables were compared using the Chi-square test, and continuous variables were analyzed using the Independent t-test. A p-value of <0.05 was considered statistically significant.

In the present study, a total of 80 patients undergoing elective general surgical procedures were included. Among them, 40 patients received only intravenous (IV) Ceftriaxone (Group A), while the remaining 40 received both intravenous and intra-incisional Ceftriaxone (Group B). The groups were compared in terms of demographic parameters, incidence of surgical site infections (SSI), vital signs, laboratory parameters, microbiological profiles, and antibiotic sensitivity.

Table 1: Profile of Subjects

In the present study, the majority of subjects were in the 36–65 year age group (65%, n=52). In Group A, 24 patients (60%) were aged 36–65 years and 16 (40%) were below 35 years. In Group B, 28 patients (70%) were aged 36–65 years, and 12 (30%) were below 35 years. There was no significant difference in age distribution between the two groups.

Out of the 80 patients, 58 (72.5%) were male and 22 (27.5%) were female. In Group A, 30 (75%) were male and 10 (25%) were female, while Group B included 28 (70%) males and 12 (30%) females. There was no statistically significant gender difference between the groups.

In terms of surgical procedures, 53 (66.2%) patients underwent surgery for inguinal hernia and 27 (33.7%) for appendicitis. Group A had 26 (65%) inguinal hernia and 14 (35%) appendicitis cases, while Group B had 27 (67.5%) inguinal hernia and 13 (32.5%) appendicitis cases. Surgical indications were similar across both groups.

Table 2: Incidence of Surgical Site Infections (SSI)

Chi-square test

In the present study, the overall incidence of SSI was 11.25% (9 out of 80 patients). In Group A, 7 patients (17.5%) developed SSI, whereas in Group B only 2 patients (5%) developed SSI. The difference in incidence was statistically significant with a P-value of 0.04 (Chi-square test), indicating that the combined intravenous and intra-incisional antibiotic prophylaxis in Group B significantly reduced the risk of SSI compared to intravenous prophylaxis alone.

Table 3: Comparison of Vital and Laboratory Parameters

Independent t test

The mean systolic blood pressure (SBP) in Group A was 120.1 ± 7.10 mmHg and in Group B was 118.9 ± 8.17 mmHg. The difference was not statistically significant (P = 0.369). Similarly, the mean diastolic blood pressure (DBP) was 78.24 ± 5.45 mmHg in Group A and 76.68 ± 4.84 mmHg in Group B, which was also not significant (P = 0.133).

The mean hemoglobin percentage (Hb%) was significantly higher in Group A (12.45 ± 1.37%) compared to Group B (11.67 ± 1.56%), with a P-value of 0.011, indicating statistical significance.

The mean random blood sugar (RBS) was 114.1 ± 6.87 mg/dL in Group A and 111.28 ± 5.52 mg/dL in Group B. This difference was also statistically significant (P = 0.023).

The mean duration of surgery was 49.7 ± 11.8 minutes in Group A and 47.3 ± 7.3 minutes in Group B. This difference was not statistically significant (P = 0.224), indicating comparable surgical durations between the groups.

Table 4: Type of Organism Isolated

Among the 9 patients who developed SSI, the most commonly isolated organism was Staphylococcus aureus, accounting for 6 cases (66.6%), followed by Klebsiella species in 2 cases (22.2%) and Pseudomonas aeruginosa in 1 case (11.1%). In Group A, 5 out of 7 infections were due to Staphylococcus aureus, with 1 each due to Klebsiella and Pseudomonas. In Group B, 1 case was due to Staphylococcus aureus and 1 due to Klebsiella. The distribution of organisms suggests a higher microbial burden in the IV-only group.

Table 5: Antibiotic Sensitivity Pattern

In Group A, out of the 7 organisms isolated, 4 were sensitive to Amikacin and Doxycycline, 3 to Cefotaxime, 5 to Ceftriaxone and Piperacillin–Tazobactam, and 6 to Meropenem. In Group B, both isolates were sensitive to Piperacillin–Tazobactam and Meropenem, and one isolate each showed sensitivity to Amikacin, Doxycycline, Cefotaxime, and Ceftriaxone.

These findings indicate that Meropenem and Piperacillin–Tazobactam were the most effective antibiotics against organisms causing SSI in both groups, while first-line antibiotics such as Ceftriaxone showed reduced sensitivity, particularly in Group A.

In the present study, the age and gender distribution were comparable between the two groups, with no statistically significant difference. A majority (65%) of patients were between 36–65 years. Similar demographic patterns were reported in studies by Kamat et al. and Mauermann et al.¹¹. The slight male predominance observed here (72.5%) is in line with surgical procedure trends reported in South Asian studies, especially for hernia repairs and appendectomies³.

In terms of surgery types, the distribution between inguinal hernia and appendectomy was balanced across both groups, aligning with patterns observed in studies by Nagachinta et al. and Bennett-Guerrero et al.¹² ¹³.

The incidence of SSIs in Group B (5%) was significantly lower than in Group A (17.5%), with a p-value of 0.04, suggesting that the addition of intra-incisional ceftriaxone significantly reduces SSI risk. This finding aligns with prior studies by Dellinger et al. and Namakula et al.¹⁴ ¹⁵. Miserez et al. also found that intra-wound antibiotic delivery in clean surgeries lowered the SSI incidence to <6%¹⁶.

Variations in SSI rates between studies may be attributed to differences in microbial flora, surgical asepsis protocols, or antibiotic resistance patterns. For instance, Nagle et al. reported higher SSI rates with IV-only regimens in tropical environments, reinforcing the need for tailored prophylactic strategies¹⁷.

The mean blood pressure and surgical duration were comparable between groups, indicating well-matched baseline and procedural characteristics. However, statistically significant differences were noted in hemoglobin (Hb%) and random blood sugar (RBS) levels. Group A had slightly higher Hb% and RBS levels, possibly reflecting inter-individual nutritional or metabolic variability rather than intervention effects.

Similar outcomes were reported by Tang et al., who noted that mild variations in Hb% did not impact SSI rates significantly¹⁸. Chen et al. also observed that postoperative glycemic control plays a more crucial role than baseline glucose levels in predicting SSI risk¹⁹.

Staphylococcus aureus was the most common organism isolated (66.6%), followed by Klebsiella spp. and Pseudomonas aeruginosa. These findings echo those reported by Mangram et al. and Weigelt et al., who noted that S. aureus accounts for over 60% of SSIs in clean and clean-contaminated surgeries²⁰ ²¹. The higher microbial burden in Group A may be due to limited tissue-level concentration of antibiotics, a limitation mitigated by local infiltration in Group B.

In both groups, organisms showed highest sensitivity to Meropenem and Piperacillin–Tazobactam, while Ceftriaxone, though used prophylactically, demonstrated moderate resistance. This pattern is increasingly seen in recent studies by Gandra et al. and Laxminarayan et al., which highlight rising resistance to third-generation cephalosporins in Indian hospitals²² ²³.

The added intra-incisional application may enhance local bioavailability, improving prophylactic efficacy despite systemic resistance trends. As de Jonge et al. suggest, antibiotic tissue concentration at the incision site is crucial for preventing early colonization²⁴.

This study demonstrated that the addition of intra-incisional antibiotic prophylaxis to standard intravenous (IV) administration significantly reduced the incidence of surgical site infections (SSIs) in patients undergoing elective clean and clean-contaminated general surgical procedures. Staphylococcus aureus was the most frequently isolated organism from infected wounds, consistent with global trends in SSI etiology. Although no statistically significant association was found between the duration of surgery and SSI occurrence, a higher incidence was observed among patients aged over 40 years.

Importantly, intra-incisional administration of ceftriaxone was well tolerated, with no adverse reactions noted, suggesting that it is a safe adjunctive method for local antibiotic delivery. The superior outcomes observed in the combination group may be attributed to the enhanced local concentration of antibiotics at the surgical site. However, further large-scale, randomized controlled trials are needed to validate these findings and assess pharmacokinetic parameters such as tissue penetration and drug distribution in subcutaneous and adipose tissues.

1. Williams NS, O’Connell PR, McCaskie A. Bailey & Love’s Short Practice of Surgery. 25th ed. London: Hodder Arnold; 2008.
2. Watanabe A, Kohnoe S, Shimabukuro R, et al. Risk factors associated with surgical site infection in upper and lower gastrointestinal surgery. Surg Today. 2008;38(5):404–12.
3. Singh R, Sinha R, Mishra P, Yadav A. Surgical site infections: a five-year prospective study. J Clin Diagn Res. 2018;12(7):DC01–03.
4. Davidson AIG, Clark G, Smith G. Postoperative wound infection: a computer analysis. Br J Surg. 1971;58(5):333–7.
5. McKittrick LS, Wheelock FC Jr. The routine use of antibiotics in elective abdominal surgery. Surg Gynecol Obstet. 1954;99:376–7.
6. Burke J. The effective period of preventive antibiotic action in experimental incisions and dermal lesions. Surgery. 1961;50(1):161–8.
7. Polk HC Jr, Lopez-Mayor JF. Postoperative wound infection: a prospective study of determinant factors and prevention. Surgery. 1969;66(1):97–103.
8. Armstrong CP, Taylor TV, Reeves DS. Pre-incisional intraparietal injection of cefamandole: a new approach to wound infection prophylaxis. Br J Surg. 1982;69(7):459–60.
9. Classen DC, Evans RS, Pestotnik SL, et al. The timing of prophylactic administration of antibiotics and the risk of surgical wound infection. N Engl J Med. 1992;326(5):281–6.
10. Kamat US, Ferreira AM, Savio R, Motghare DD. Antimicrobial resistance among nosocomial isolates in a teaching hospital in Goa. Indian J Community Med. 2008;33(2):89–92.
11. Mauermann WJ, Rooke TW, Kalra M, et al. Risk factors for surgical site infections following open lower extremity revascularization procedures. Vasc Endovascular Surg. 2008;42(6):486–93.
12. Nagachinta T, Stephens M, Reitz B, Polk BF. Risk factors for surgical-wound infection following cardiac surgery. J Infect Dis. 1987;156(6):967–73.
13. Bennett-Guerrero E, Pappas TN, Koltun WA, et al. Gentamicin-collagen sponge for infection prophylaxis in colorectal surgery. N Engl J Med. 2010;363(11):1038–49.
14. Dellinger EP, Hausmann SM, Bratzler DW, et al. Hospitals collaborate to decrease surgical site infections. Am J Surg. 2005;190(1):9–15.
15. Namakula R, Kitara DL. Surgical site infections in a general hospital in northern Uganda: a cross-sectional study. East Cent Afr J Surg. 2014;19(1):110–7.
16. Miserez M, Peeters E, Aufenacker T, et al. Update with level 1 studies of the European Hernia Society guidelines on the treatment of inguinal hernia in adult patients. Hernia. 2014;18(2):151–63.
17. Nagle D, Abcarian H. Surgical site infections: prevention and management. Clin Colon Rectal Surg. 2011;24(3):168–76.
18. Tang R, Chen HH, Wang YL, et al. Risk factors for surgical site infection after elective resection of the colon and rectum. Ann Surg. 2001;234(2):181–9.
19. Chen TY, Chen SY, Kao WF, et al. Impact of hyperglycemia and glucose variability on surgical site infection after open abdominal surgery. J Hosp Infect. 2013;84(2):104–11.
20. Mangram AJ, Horan TC, Pearson ML, et al. Guideline for prevention of surgical site infection, 1999. Infect Control Hosp Epidemiol. 1999;20(4):250–78.
21. Weigelt JA, Lipsky BA, Tabak YP, et al. Surgical site infections: causative pathogens and associated outcomes. Am J Infect Control. 2010;38(2):112–20.
22. Gandra S, Mojica N, Klein EY, et al. Trends in antibiotic resistance among major bacterial pathogens isolated from blood cultures tested at a large private laboratory network in India, 2008–2014. Int J Infect Dis. 2016;50:75–82.
23. Laxminarayan R, Chaudhury RR. Antibiotic resistance in India: drivers and opportunities for action. PLoS Med. 2016;13(3):e1001974.
24. de Jonge SW, Boldingh QJJ, Solomkin JS, et al. Systematic review and meta-analysis of randomized controlled trials evaluating prophylactic intra-operative wound irrigation for the prevention of surgical site infections. Surg Infect (Larchmt). 2017;18(4):508–19.