In short. Different organisms, different drugs, and a course that is chosen rather than guessed. Why a borrowed or unfinished course is a problem.
Key points
- A useful question at the assessment is what the treatment is for and whether a sample has been taken to establish it.
- A clinician who can say which organism is suspected, or that a sample has been sent and the treatment will be adjusted when it returns, is treating the cause.
- A treatment that continues unchanged without any attempt to establish the cause is one that is being managed by appearance alone.
An antibiotic is chosen for a cause rather than for a symptom. That is the whole of the reasoning, and it explains nearly every piece of advice on this page, including why a course is finished and why a leftover tablet in a drawer is not a solution.
Different organisms, different treatments
The organisms that cause infection after a procedure are not all the same, and they do not all respond to the same treatment. Some are common on the skin, some come from the environment, and some are resistant to the treatments that would once have dealt with them. Establishing which is present, by sampling before treatment starts, is what allows the choice to be made for the cause rather than for the appearance. Where the organism is not known, a choice is made on the clinical picture and then adjusted once the result is available — which is a reasonable approach and a different thing from choosing at random.
Ask what the treatment is aimed at
A useful question at the assessment is what the treatment is for and whether a sample has been taken to establish it. A clinician who can say which organism is suspected, or that a sample has been sent and the treatment will be adjusted when it returns, is treating the cause. A treatment that continues unchanged without any attempt to establish the cause is one that is being managed by appearance alone.
Why course length matters
Because the duration is set for the infection being treated rather than for the appearance of the wound after a few days. Stopping when the wound looks better leaves the process incompletely treated, and the signs can return. The same applies in reverse: continuing treatment that is not working, without reassessing, delays the change that is needed, which is why a repeat assessment matters if the wound is not improving.
Why a borrowed or incomplete course is a problem
It was chosen for a different organism in a different person, at a duration set for that situation, and it may be the wrong choice, the wrong length, or unsuitable for you. It also partially suppresses whatever is present, which makes a sample less likely to identify the organism when it is eventually taken. The result is a clinician choosing treatment without knowing the cause, which usually means a broader choice and a longer course than the situation required.
What not to do with antibiotics
- Do not take one prescribed for someone else, or left over from a previous course.
- Do not stop a course early because the wound looks better, or continue one that is not working.
- Do not start treatment before a sample has been taken if a sample is going to be taken at all.
The principle is short enough to remember: treatment is chosen for a cause, the cause is established before treatment where it can be, and the course is finished because the duration is set for the infection rather than for the appearance.
Frequently asked questions
Why can I not just take a broad antibiotic?
Because a broad choice treats more than the cause and often less effectively than a targeted one, and because it selects for organisms that are harder to treat. Where the organism is known, treatment is chosen for it. Where it is not, a choice is made on the clinical picture and then adjusted once the laboratory result is available.
Why does the course have to be finished?
Because stopping early leaves the process incompletely treated, and the signs can return. A partially treated infection is also harder to sample afterwards, because the organism may not grow. The duration is set for the infection being treated rather than for how the wound looks after a few days.
Why should I not use someone else's antibiotic?
Because it was chosen for a different organism in a different person, and it may be the wrong choice for yours, the wrong duration, or unsuitable for you. It also complicates the assessment, because whatever is present has been partially suppressed by the time anyone looks at it properly.
Risks & Limitations
- Redness and warmth are the first stage of healing as well as the first sign of infection. Direction and speed decide the question, so a margin that advances over hours is the finding rather than the presence of redness.
- An infection that is spreading can move quickly. Spreading redness, a red line tracking up a limb, fever with chills, and skin turning dusky or black all need emergency care rather than a review appointment.
- An antibiotic has to match the organism. A course taken from a drawer, or one that is stopped early, treats the wrong cause or treats it inadequately and makes the next assessment harder.
- An implant has no blood supply of its own, so an infection beside it behaves differently and can be present with far less to see. It is seen the same day rather than watched.
- Where an infection needs an operation, the aim is to preserve tissue that is still viable and to end the infection. It cannot restore tissue that has already been destroyed.
- No assessment predicts an infection exactly, which is why the warning findings are taught to every patient rather than only to those at higher risk.
When to Seek Care
- Redness that is spreading outward, or a red line tracking up a limb &mdash — seek emergency care now.
- Fever with chills, shivering, or feeling generally very unwell &mdash — seek emergency care now.
- Skin around the wound turning dusky, blistered or black &mdash — seek emergency care now.
- Pus, or discharge that has become thick, yellow-green or foul-smelling — contact the team the same day.
- Increasing pain, heat and swelling after the first week, or a wound that is opening.
- A red, hot, tender area around an implant or an injected area.
References & Further Reading
- American Society of Plastic Surgeons (ASPS) - patient safety guidance on surgical site infection
- National Institute for Health and Care Excellence (NICE, UK) - guidance on surgical site infection prevention and management
- Cochrane Library - systematic reviews on antibiotic prophylaxis and wound care in surgery
- British Association of Plastic, Reconstructive and Aesthetic Surgeons (BAPRAS) - patient information on wound care after surgery
- Chinese Medical Association Plastic Surgery Branch - clinical guidance
This page is patient education, not medical advice, and it does not cite individual studies. Discuss your own case with a qualified clinician. To arrange an assessment at Chongqing West District Hospital, see Contact & Consultation.