Tag Archives: MRSA

Abscess Incision and Drainage, a Photographic Tutorial

Skin abscesses are quite common in correctional facilities, especially in the MRSA era, and so all correctional practitioners need to be comfortable with the procedure of abscess incision and drainage, also known as “lancing” the abscess.  Also “Let’s cut that sucker open.”  However, I’m going to be professional and call this procedure “I&D” for “Incision and Drainage.”

When I was just starting out in emergency medicine, I&D seemed to be quite a daunting task.  I was afraid of making a mistake and hurting someone or making them worse.  However, in actual fact, I&D is quite easy.  You can potentially hurt people more by not doing an I&D than by doing one.

But, like all medical procedures, it is possible to do the procedure poorly and inefficiently or to make outright mistakes.  The subject of today’s post is how to do a simple I&D of a skin abscess.  The opportunity to take pictures of the procedure arose when a fireman friend of mine walked in to my office and asked me to look at a lump on his back that had been there for a few days.  It was quite sore.  Here is a picture of the lump:

This appears to me to be a MRSA abscess.  Statistically, MRSA causes approximately 75% of all community acquired skin abscesses.  But beyond the statistical likelihood, this looks like a MRSA abscess.  It has lots of pus for its size along with a central area where the lesion is “pointing.”  This appearance is commonly mistaken for a “spider bite” by the lay public.

Why did my friend get a MRSA lesion on his back?  I don’t know.  Why does one member of a family get strep throat but not the others?  It just happens.  Usually, the only way to pinpoint the source is when multiple patients with a common background get MRSA, like members of a wrestling team or inmates housed in the same dorm.  A single, isolated case like this just happens—and not infrequently.

The treatment for MRSA abscess is Incision and Drainage, so I am going to cut this sucker open to let it drain—oops!  I mean I am going to perform an I&D procedure and document the process with pictures and discuss each step.  The process of I&D consists of these steps:

  1.  Skin cleaning.  I did this using alcohol wipes.  It is important to remember that this is not a sterile procedure—even if you do a surgically prep and drape the skin and use sterile gloves, they will not remain sterile once everything is covered by pus from the abscess!  Instead, this is a clean procedure.  You want everything to be clean, but you do not have to perform a formal surgical prep.
  2. Anesthesia.  I prefer to use 0.25% bupivicaine (Marcaine) with epinephrine.  Why Marcaine instead of lidocaine?  Well, they are comparable in price and Marcaine has the advantage of lasting 3-4 times longer, so the area stays numb for 12-16 hours instead of 4 hours.  Why use epinephrine?  The main reason to use epinephrine is that it constricts skin blood vessels so there is much less bleeding.  This makes the procedure that much easier to perform.  Epi also makes the anesthesia last longer—another bonus for the patient!
  3. Make the incision.  I prefer to use a #15 blade scalpel rather than the traditional #11 blade—but either will work.  The most common mistake made when incising an abscess is not to make the incision big enough.  The incision needs to be long enough and deep enough to allow access to the abscess cavity later, when you explore the abscess cavity.  Note that my incision stretches the whole diameter of the abscess—all the way from the top edge of redness to the bottom edge of redness.  Notice also that I have chosen in this case to make the incision run across the lines of tension of the skin by incising from top to bottom.  Typically, you would make an incision run the same direction as the skin creases if you want to minimize the scar.  I don’t care too much about a scar in this case, since the lesion is on the patient’s back.  I am more concerned with adequate drainage of the wound.  By making the incision perpendicular to the creases, the skin will naturally gape open after the procedure and allow pus to drain.  Not allowing the skin edges to touch and potentially re-seal is also the reason for placing packing in the wound, which we will discuss later.
  4. Squeeze out the pus.  This abscess had quite a bit of pus.  By the way, you do not have to routinely send this pus for culture in the majority of young healthy patients, especially if you are not going to prescribe an antibiotic (discussed later).  Culture is a good idea in complicated cases, such as immunocompromised patients, or large complicated abscesses.
  5. Explore the abscess cavity.  There are several reasons to do this.  The first is to see how deep the abscess goes.  Some abscesses are like icebergs—what you see at the surface is only a small portion of the whole abscess.  Some can run amazingly deep.  You should find the full extent of the abscess cavity.  Second, many abscesses have multiple chambers and your incision may have only drained one.  By exploring the cavity, you will break any remaining abscess walls and make sure the entire abscess has drained.  Finally, many abscesses have thick, adherent pus stuck to the walls that does not drain easily.  By rubbing the inner walls of the abscess, you will loosen that thick pus and get it out.  How to explore the abscess cavity depends on the abscess size. I have found that the best instrument for exploring bigger abscess is my gloved finger, as I have done here (as long as you are sure there are no foreign bodies in the abscess).  I have seen surgeons get their whole hand inside really big abscesses (of course abscesses that big probably should be sent to a surgeon).  On the other hand, you may not be able to get your finger into a small abscess.  A curved mosquito forceps with some gauze at the tip works well in those cases.
  6. Irrigate the interior of the abscess with saline.  This is done to make sure that we have all of the pus out.  When the saline draining out of the abscess is clear, the abscess cavity is clean.
  7. Insert a packAbscess packing is perhaps the single most misunderstood aspect of abscess I&D.  The purpose of the packing is to prevent the skin edges from re-sealing.  It is a mistake to think that the packing aids healing.  It does not.  There needs to be enough packing in the interior of the abscess cavity to prevent the wick from falling out, but there is no benefit to stuffing a ton of packing into the abscess.  In fact, that is detrimental, because the packing is a foreign body and because if the packing is packed so tightly so as to exert pressure, it can cause tissue necrosis.  In fact, not every abscess needs to be packed.  If the opening is gaping so widely that there is little chance of the edges re-sealing together, there may be no need for packing.  This point is so important that I will say it again:  abscess packing material is a foreign body.  It can delay healing and resolution of the abscess.  Its only function is to prevent the skin edges from re-sealing. The packing I place today will be removed tomorrow.  I don’t want it in there very long.  It is a foreign body.
  8. Place a dressing.  The first 24 hours after an I&D, the abscess will continue to weep, so it is nice to have an occlusive dressing to prevent he wound from weeping all over clothes and bedding and the inmate’s roommate.
  9. The next day, remove the packing.  Since the packing is a foreign body, it should be removed as quickly as possible.  Notice that this abscess seems reasonably dry after one day.  If the wound were still draining pus, that might mean that I had not fully cleaned out the abscess interior, and I might need to re-explore the abscess to see what I missed.
  10. Leave the abscess openPatients at this stage can shower and I encourage them to let the water wash out the interior of the cavity.  Over the next week or two, the abscess will heal in from the bottom out.
  11. Antibiotics? There is a large body of literature that says antibiotics should not be routinely prescribed for MRSA abscesses as long as they can be fully drained and as long as the patient is otherwise healthy and there is no accompanying cellulitis.  This patient is healthy and I see no cellulitis surrounding the abscess, so I am not going to use antibiotics.

This entire procedure took literally about 10 minutes to do.  It turned out well.

ADDENDUM (12/12/12)  This is a picture of the site one week post procedure.  It appears to be healing well.  The skin rash reaction to the dressing tape looks worse than the wound!IMG_0189

Mandatory disclaimer:  The technique I used here is a result of my Emergency Medicine training, my experience and my preferences.  Other practitioners may use other techniques that are just as effective.  Some may even disagree with what I have said here!  You should develop your own technique based on your training, experience and preferences!  A very good official source for the technique of abscess I&D is Roberts: Clinical Procedures in Emergency Medicine, 5th ed.  Chapter 37, Incision and Drainage.  Also, I am talking here about simple abscesses.  Abscesses in complicated areas such as the hands, neck or anus or abscesses of the face where the inevitable procedural scar will be visible may be best sent to a specialist to drain.

Do you have a different technique that you use to I&D abscesses?  Please comment!

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Reader Question About Antibiotic Use. What’s Your Opinion?

My name is Gabby and I am a ARNP working in  a rural health care setting in southern Washington and newly blessed with a county jail assignment.  I oversee 300 + inmates in a county jail setting and was turned onto your website by one of the RN’s in the medical office at the jail.  Thank you so much for the wonderful information that you share. I have some questions that I am hoping you can give me some guidance with today.

The population of patients that we deal with the most are heroin and meth users with extensive histories of dental decay and abscesses and multiple complicated skin infections from muscling heroin.  After reading your most recent posting on MRSA and misuse/overuse of antibiotics I was wondering what your thoughts would be regarding my jail’s protocols on dental abscess treatment plan with amoxicillin and skin infections/abscess treatment plan with Keflex and Bactrim.  These protocols are for the staff to use in between my visits twice a week.  A significant number of the inmates that I see are frequent flyers and often are treated with above stated protocols over and over again.  I am wondering if I need to request that these protocols be reevaluated.  And if so, what would be the new treatment recommendation that I would present look like?  Comments?

Thanks for the questions, Gabby!  And welcome to Correctional Medicine.  You’re going to love it!

I am going to answer your questions with my opinions on these topics and invite others to answer also via comments.

The two basic principles in the fight against antibiotic overuse which leads (among other things) to antibiotic resistance are:

  1. Don’t use antibiotics when you do not have to.  We’ll call this rule “Don’t Overprescribe.” I think that for years there has been the feeling in the medical community that antibiotics “Can’t hurt and might help,” so they were prescribed in lots of questionable settings.  In fact, antibiotics can hurt.  Besides microbial resistance, antibiotics have all sorts of side effects, ranging from nuisances to serious.
  2. When you do prescribe an antibiotic, use the narrowest spectrum antibiotic that will do the job.  We’ll call that the “Sledgehammer Rule,” as in “Don’t use a sledgehammer to hang a picture on your wall—you are more likely to cause damage than to do a good job.”

So let’s apply these rules to your cases, first, the dental infection case.

  1. Don’t overprescribe.  The danger here is over diagnosing infections that don’t exist.  Don’t prescribe antibiotics for a simple toothache.  Reserve the antibiotics for some objective evidence of infection:  facial or gum swelling, visible abscess, purulent gums, something.  Just because the patient has a toothache does not mean they have an infection.  Simple toothaches need some sort of pain management and certainly need a dental referral, but not usually an antibiotic.  Look carefully.  If you are not sure and can’t get them in to see the dentist right away, then recheck them again tomorrow.
  2. The Sledgehammer Rule. The organisms that tend to cause oral infections are usually still sensitive to plain penicillin, as in Penicillin VK  1000mg po BID.  There is no advantage in most cases to using broader spectrum agents like amoxicillin, Augmentin or Keflex.  We want to reserve these agents for infections already resistant to penicillin.  Similarly, plain penicillin is still the recommended first line agent for strep throat.

Antibiotics? NO! Incision and Drainage!

Second question–MRSA.  MRSA infections are increasingly becoming resistant to the very few agents available to treat them, so I think it is especially important to apply the two rules to these infections.

  1. Don’t overprescribe.  There is quite a lot of literature supporting the idea that you do NOT have to prescribe antibiotics following MRSA abscess I&D.  The treatment for any abscess is adequate incision and drainage.  You do not get any better resolution in most MRSA patients if you follow I&D with antibiotics.
  2. The Sledgehammer Rule.  I think that it is seldom good practice to prescribe both Kelfex and Bactrim simultaneously.  I know this is done outside of corrections, especially in ERs.  The rationale is that without a formal culture, you are not 100% sure if this particular cellulitis is caused by methicillin resistant staph (resistant to Keflex, sensitive to Bactrim) or methicillin sensitive staph (resistant to Bactrim, sensitive to Keflex), and so, to cover all your bases, you prescribe both.  However, personally, I think it is pretty easy to tell the difference between most cases of MRSA and non-MRSA infections just by looking at them.  The MRSA organism is an abscess former, and so, even early on, MRSA infections tend to form an abscess or at least show a central “spider bite” core.  Meth sensitive cellulitis usually does not have either. Make your best guess, maybe based on a picture the nurses send you if you are not right there, and re-evaluate as needed tomorrow or the next day.  You will pick correctly 95% of the time.

Finally, what about those patients who get recurring MRSA abscesses?  The patients who get recurring MRSA abscesses are typically MRSA carriers, and your goal then is to eradicate their carrier status.  There are several ways to do this according to MRSA guidelines (such as these by the Infectious Disease Society of America)—here are three:

  1. Apply mupiricin (Bactroban) 2% ointment to both nostrils (where MRSA tends to hang out in carriers) twice a day for ten days.
  2. Chlorhexadine body wash once a day for 5 days.
  3. Rifampin 600 mg po BID for five days in addition to your primary MRSA drug, whether Bactrim or Doxycycline—don’t prescribe rifampin alone.

Disclaimers:

We are talking here about typical young healthy patients.  Patients who have chronic health problems or are immunocompromised must be approached differently.

Also, The opinions here are my own.  I could be wrong; feel free to disagree!  But if you do, please comment so Gabby will have the benefit of other opinions and approaches.

Interesting Study of the Week–MRSA

Antibacterial drugs and the risk of community-associated methicillin-resistant Staphylococcus aureus in children. Schneider-Lindner, et.al., Arch Pedicatr Adolesc Med, 2011 Dec:165(12):1107-14.

This is a great study done in England, where a database of medical treatment for the whole country is available for research (unlike in the US).  These researchers asked the question, “If you are prescribed an antibiotic, does that increase your risk of subsequently contracting a MRSA infection?”  So the researchers reviewed records for children between 1994 and 2007, including ~300 MRSA cases and >9000 controls.

Not surprisingly, they found that a child who is prescribed an antibiotic does, in fact, have an increased risk of a subsequent MRSA infection.  The surprising thing is how much of an increased risk this represents.

If you receive one antibiotic prescription, your risk of MRSA infection within the next 6 months more than doubles. If you receive two antibiotic prescriptions within 150 days, your risk of MRSA more than triples.  Then the risk really goes up.  If your receive three antibiotic prescriptions within 150 days, your risk of subsequent MRSA infection goes up eleven fold.  Four antibiotic prescriptions and your risk for MRSA rises more than 18 fold.

Quinalones are particularly prone to increase the risk of subsequent MRSA infections.

These researchers had previously studied adults and found the same thing.  (Antimicrobial drugs and community-acquired methicillin-resistant Staphylococcus aureus, United Kingdom).

Perfect lawn

I’m going to prevent weeds by killing the grass.

This, of course, makes sense.  A great analogy that I like to use with inmates who want an antibiotic prescription for their viral syndrome is of a lawn of grass.  The grass itself prevents noxious weeds, like thistle, from sprouting.  The grass chokes them out.  But if I were to kill the grass by spraying Roundup, what are the odds that thistle will grow now?  The grass is like our normal, healthy colonies of bacteria.  They help us in many ways, including “choking out” noxious bacteria like MRSA. There has been some great recent research into the beneficial effects of our personal bacterial colonies, such as this report on the  Human Biome Project.

Using antibiotics is very like using grass killer.  Antibiotics are a great medical tool when used properly, but they also have the potential to cause great harm.  If you prescribe an antibiotic for a viral syndrome, like a typical case of sore throat or bronchitis, your potential for benefit is zero.  It’s a virus!  But your potential for harm is the same as it always is.  This study shows that one unnecessary prescription doubles your patient’s subsequent risk of MRSA.  If you prescribe Augmentin, the risk of diarrhea is one in six!  So you cannot help this patient with a virus by prescribing an antibiotic; you can only harm them.

The CDC has published excellent guidelines on the proper use of antibiotics for sore throats, bronchitis and sinusitis.  I have written about these guidelines previously here (Evidence-Based Use of Antibiotics Can Save Your Jail Money! and here (Don’t Use Antibiotics for Most Cases of Pharyngitis!, although my focus then was how inappropriate antibiotic prescribing wastes money.

The more important message is that inappropriate antibiotic prescribing harms your patients.  According to these studies, if you reduce your antibiotic prescribing by following these guidelines, you may find that your MRSA infection rate goes down, too! Bonus!

 

 

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