Chapter 10 Field Sterility for Simple Cases Makes Sense
FIELD STERILITY VERSUS FULL STERILITY
In this book, field sterility, as shown below, means creating a localized sterile field with four towels or a small 40 × 40 cm drape with a hole in it. We only expose and sterilize the part we are operating on or need to see move during the surgery. The surgeon has a mask and sterile gloves, but no sterile gown. Laminar airflow is not required.
In this book, full sterility means standard operating room full draping with the entire patient covered in sterile drapes, with surgeons and nurses in sterile operating gowns, masks, and gloves.
FULL STERILITY VERSUS FIELD STERILITY FOR MINOR PROCEDURES: WHAT IS THE EVIDENCE?
Plastic surgeons all over the world have excised small skin cancers and benign lesions with field sterility outside the main operating room for well over 80 years, with no red flags of excessive incidence of infection. The standard of care of Mohs surgery skin cancer excision everywhere in the United States is field sterility outside the main operating room. A recent prospective American cohort study of 20,871 cases of Mohs surgery with field sterility revealed an infection rate of 0.37% with only 78 infections.1 This infection rate is almost identical to the 1500-case series field sterility carpal tunnel infection rate discussed next.
What is the evidence for field sterility infection in hand surgery? In a prospective consecutive series of 1504 field sterility carpal tunnel procedures in five North American cities by six surgeons,2 only six patients developed superficial infections, none of which required incision and drainage; no intravenous antibiotics were given, no reoperation was necessary, and none of the patients required hospital admission. Two infections resolved with suture removal and no antibiotics, and only four patients required oral antibiotics. None of these patients had been given preoperative antibiotics. The infection rate in that 1504-case series was 0.39%, almost identical to the Mohs 20,871-case series described earlier.
For many years, Canadian hand surgeons have been doing most carpal tunnel and trigger finger operations with field sterility in minor procedure rooms with very few infections.3 The patient doesn′t need to suffer the embarrassment of getting undressed and being transported on a stretcher, although perfectly healthy. There is no monitoring. He or she simply rolls up a sleeve, has the surgery, and then gets up and goes home.
There is no evidence that outcomes in carpal tunnel surgery are better with full sterility than with field sterility. However, the cost is at least four times as much, the efficiency is half as much, and the garbage production is more than ten times greater.3
Most simple hand trauma operations in Calgary, Saskatoon, Ottawa, Saint John, and other Canadian cities happen with field sterility as well. Those Canadian hand surgeons are repairing tendons and K-wiring most fractures outside the main operating room in clinic procedure rooms Monday through Friday, 8 AM to 5 PM. Calgary has dedicated field sterility clinic trauma rooms on weekend daytime hours as well. Patients may get a better tendon repair at 2 PM than at 2 AM when surgeons and nurses are sleepy.
Just over a century ago, humans discovered how to safely administer a local anesthetic or induce sedation and general anesthesia to make surgery easier, less painful, and safer. We now know that we don′t always need general anesthesia, especially if we are not hurting patients when we inject a local anesthetic. More anesthetic is not always better than less anesthetic. Likewise, more sterility is not necessarily always better than less sterility.
If we were to follow the premise that more sterility is always better than less sterility, we would all be using “space-suit” sterility measures, as shown below, even for drawing blood or starting an intravenous line. After all, that little plastic intravenous catheter that has contacted bacteria on the skin is placed in a vein with a direct line to the heart! However, we all would agree that we don′t need that much sterility for a venipuncture or starting an IV.
The human and financial cost of an infection after venipuncture or intravenous insertion does not warrant the cost of space-suit sterility, both in terms of human suffering and in dollars. Infections are not common and are usually easily dealt with inexpensively.
Where does trigger finger or carpal tunnel surgery fit between drawing blood and knee implant insertion? We need to look at the downside of infection to learn the answer. What are the usual problems associated with infection after carpal tunnel surgery? Not many. Most people respond to suture removal, oral antibiotics, elevation, and immobilization. Very few ever need incision and drainage plus administration of intravenous antibiotics. Most hand surgeons have never seen devastating infection after carpal tunnel surgery because it is so rare. Is it reasonable to spend vast amounts of money for full sterility and millions of tons of medical waste every year to prevent a problem that may not even exist? Probably not.
We need better evidence, such as the studies cited earlier, to guide the appropriate amount of sterility for which we spend a lot of money. We need to use solid evidence to help us make wise decisions as we fine-tune how much sterility we really need to do each of the various invasive procedures we perform safely. Patients can′t afford the cost, surgeons and hospitals can′t afford the cost, and the world does not need the garbage produced unnecessarily by the false assumption that more sterility measures are always better.4
When full sterility is required for a procedure such as inserting a permanent PIP joint implant, the wide awake hand operation can be moved to the main operating room or theater with full sterility and laminar airflow.
The blood supply to the hand is excellent, which is why most hand lacerations sutured in the emergency department do not develop infection, despite the fact that many of those lacerations occurred in severely contaminated hands. Before such lacerations occur, no prepping and draping is done, and no antibiotics are given.
Now that we no longer need the tourniquet and sedation for hand surgery, field sterility permits us to perform minor hand surgery for carpal tunnel release and minor hand trauma outside the main operating room, which greatly decreases the cost of the surgery3–6 (see Chapter 11).