Surgical site infection (SSI) is a serious postoperative complication after cardiac surgery that have a negative impact on a patient's health and survival. This study aims to investigate the effectiveness of administering gentamicin in reducing the incidence of SSI with monitoring to the effective therapeutic level.

Gentamicin is an aminoglycoside antibiotic that exhibits a wide range of antibacterial effects, mostly targeting Gram-negative bacteria, while its effectiveness against Gram-positive organisms is comparatively weaker. Gentamicin has significant efficacy against multidrug-resistant bacteria as well. Gentamicin is often used in conjunction with beta-lactam antibiotics to provide enhanced therapeutic efficacy via a synergistic effect, particularly in cases of Gram-positive and multidrug-resistant bacterial infections.

This study aims to evaluate the efficacy of administering gentamicin in combination with flucloxacillin as a pre-medication and for 48 hours after surgery in reducing the incidence of surgical site infections in patients undergoing cardiac surgeries, as compared to using a combination of ceftriaxone and flucloxacillin. Additionally, the study aimed to observes the therapeutic level of gentamicin required to achieve an effective concentration of the drug.

A prospective comparative study was conducted using an appropriate sample of 50 Iraqi patients undergone several types of cardiac surgeries.

A total of 50 patients (34 males and 16 females) between the ages of 18 and 75 were included in this study. These patients were admitted to the Surgical Department of the Iraqi Center for Heart Disease over a one-year period from January 2020 to January 2021. All patients underwent various types of cardiac surgery, such as coronary artery bypass graft (CABG), valve replacement, or device placement. The same surgical and anesthesia teams conducted the procedures.

A computerized randomization method was used to allocate patients into two groups in a randomized manner. Following the first interview, the patients were sequentially assigned numbers and then randomized into two groups via the online program Research Randomizer

Inclusion Criteria:

• The research included individuals of both genders.
• Patients aged 18 and above.
• Patients had undergone any type of cardiac surgery.

Exclusion Criteria:

• Patients having a prior diagnosis of organ failure.
• Patients already on antibiotics.
• Patients with elevated baseline renal function test before operation.
• Patients with contraindications to any of the prescribed medications were excluded from this study.