Microorganisms in the OR

Any organism that can cause infection can cause an SSI (Surgical Site Infection); however, most SSIs can be traced back to organisms that are normal flora on a patient’s skin. Modern methods of disinfection can reduce but not eliminate endogenous organisms on a patient’s skin. Because some organisms reside in the hair follicles and sebaceous glands which cannot be reached with topical surgical prep, some of these structures are transected bringing these organisms into the surgical wound when an incision is made. Not all SSIs are caused by a patient’s normal flora. Microorganisms can enter a surgical site through contaminated instruments, shedding from the skin, mucous membranes, or clothing of perioperative personnel.

Microorganisms that Cause Infection:

(King & Spry, 2019)

Infections

Infection – An infection occurs whenever non-resident florae or microorganisms invade a susceptible area of the body. There is a reaction of the tissues to the microorganism’s presence and toxins are generated by the organism.

Superinfections – These occur after a patient has been treated with antibiotics and a secondary subsequent infection develops, caused by a different microorganism.

(Phillips, 2020)

Bioburden and Biofilm

Because it is not possible to sterilize a patient’s skin when using skin prep, there is always a chance that some microorganisms could be present near or at the surgical site.

Bioburden is the amount of microbial load or organic debris that can be found on something. This could include a host, such as a patient’s skin, or an inanimate object, such as a surgical instrument before it is sterilized.

Biofilm is the thin coating on an item or host that contains biologically active organisms that can grow in water, solutions, or in vivo. These organisms can coat the surface or structure of devices and can be trapped within organic matter.

Consider how organisms on surgical instruments may allow for biofilm build-up during a case. These organisms may then be detached and dispersed into the surgical site.

(Phillips, 2020)

Breaking the Chain of Infection

Because a surgical site provides an easy portal of entry for an infectious agent, antimicrobial agents are used in the perioperative environment to help break the chain of infection and prevent or reduce the risk of surgical site infections (SSIs).

Routes for Administration of Antimicrobial AgentsPO (oral) administration preoperatively or postoperatively can be given therapeutically or prophylactically:

1. Therapeutically – to eliminate organisms during an infection
2. Prophylactically – to prevent the development of an infection

(Phillips, 2020)

Patients who are undergoing surgery where antibiotic prophylaxis is recommended, need to receive the following:

1. The right type of antibiotic is based on the surgery being performed and patient characteristics such as allergies.
2. The right dose is based on the patient’s weight.
3. The right time. The initial dose is usually administered within one hour of the first incision. Additional intraoperative doses may be required based on the length of surgery and estimated blood loss.
4. The right length of treatment. Prophylactic post-op antibiotics should not be given for longer than 24 hours. Limiting the duration of postoperative prophylactic antibiotic therapy may lead to reductions in antibiotic use and in Clostridium Difficile infection.

(Public Health Ontario, 2019; WHO, 2020)

Resistance to Antibiotic Therapy

Managing new and emerging microorganisms significant in the perioperative environment