Journal Club Podcast #28: January 2016
Chris Carpenter and Mike Willman get together to talk about sterile gloves, knowledge translation, and the slippery slope of evidence-based medicine...
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1st Years: Sterile Versus Nonsterile Gloves for Repair of Uncomplicated Lacerations in the Emergency Department: A Randomized Controlled Trial, Ann Emerg Med 2004; 43: 362-370. (http://pmid.us/14985664)
2nd Years: A pilot study on the repair of contaminated traumatic wounds in the emergency department using sterile versus non-sterile gloves, Hong Kong J Emerg Med 2014; 21: 148-152. (http://tinyurl.com/HongKongJEMGloves2014)
3rd Years: Comparing non-sterile with sterile gloves for minor surgery: a prospective randomised controlled non-inferiority trial, Med J Aust 2015; 202: 27-31. (http://pmid.us/25588441)
4th Years: Comparison of the Prevalence of Surgical Site Infection with Use of Sterile Versus Nonsterile Gloves for Resection and Reconstruction During Mohs Surgery, Dermatol Surg 2014; 40: 234-239. (http://pmid.us/24446695)
Mr. C. is a healthy 45 year old male who has been constructing a covered porch in his backyard (imagine it is springtime). While working on it earlier today, he tripped over a 2x4 and stumbled through a pane of glass. After getting up, he noticed that he had cut his right thigh. The brisk bleeding subsided after his wife held pressure with a towel for 15 minutes (he was unable to do so himself as he nearly fainted at the sight of his own blood). He did not hit his head or suffer any other injuries. Upon seeing the gaping wound, several centimeters long with subcutaneous fat poking through, she promptly brought him to the ED for stitches.
In the ED, his vitals are BP 126/85, P 68, RR 18, T 37.1°C, and 100% oxygen saturation on room air. He is in no acute distress, and his exam is unremarkable, except for a 6cm laceration to his right lateral thigh. It is less than 1cm deep with only subcutaneous fat showing. X-ray shows no fractures or foreign bodies. There does not appear to be any muscle or tendon injury and he has full range of motion. The bleeding has stopped and sensation is intact throughout. There are no visible vessels, nerves, or foreign bodies on exploration.
As you irrigate the wound with tap water (why tap water rather than normal saline? See July 2008 Journal Club and updated studies by Weiss 2013 and the Cochrane Collaboration), you carefully contemplate how you are going to repair it. You decide to use a 3-0 or 4-0 non-absorbable suture due to its location (but absorbable would arguably do as well, see February 2010 Journal Club). As you gather your supplies, your attending reminds to use sterile gloves and sterile technique while doing the repair. You remember that while doing other laceration repairs on previous shifts you have been told by some attendings that you needed to use sterile gloves, but others have said that using clean, non-sterile gloves worked equally well at less cost. You decide to learn what the literature has to say about sterile gloves for ED laceration repair.
Population: Patients with acute, uncomplicated lacerations requiring closure in the ED
Intervention: Use of clean, non-sterile gloves during laceration repair
Comparison: Use of sterile gloves for laceration repairOutcome: Rate of wound infection after repair
Suture repair of traumatic lacerations occur daily in EDs around the world. The objectives of laceration repair include restoration of skin integrity with adequate post-healing cosmetic appearance, minimization of functional impairment, and avoidance of infection. Risk factors for laceration infection include diabetes, increased age, laceration width, laceration location (infection risk lower on head/neck than elsewhere), and presence of a foreign body (Hollander 2001). Many “traditional” practices continue through dogma rather than on the basis of scientific validity. Historically, suture closure was the most common method used to repair lacerations in the ED (Baker 1990), but dogma is being replaced by evidence as summarized on Skeptics Guide to Emergency Medicine (in 2012 and again in 2014), SOCMOB Blog, Life in the Fast Lane, and Manu et Corde. In addition, past Washington University EM Journal Clubs have explored the evidence-basis to support absorbable sutures and tap water irrigation. The current Journal Club challenges the long-held belief (dogma) that sterile gloves are required when repairing lacerations in the ED to prevent post-repair wound infections.
Research indicates that >105 organisms per mL are required to cause wound infection (Elek 1956, Robson 1973, Raahave 1986) in traumatic lacerations or post-op wounds. Although clean, non-sterile gloves carry a significantly higher bacterial load, the increased non-sterile glove bacterial load is not sufficient to cause infections (Creamer 2012). However, open boxes of gloves are more likely to carry bacterial contaminants, particularly when the gloves are wet (Luckey 2006, Hughes 2013). Sterile gloves at Barnes Jewish Hospital cost approximately $2.30 per pair versus $0.70 per pair of non-sterile gloves and in the busy ED frequent interruptions while suturing often translate into more than one pair of gloves being used. Therefore, an opportunity to reduce healthcare costs using non-sterile gloves during laceration repair exists. However, one 2003 Emergency Medical Journal Best Bets synopsis attempt to redefine a standard of care for ED wound repair using non-sterile gloves implied that insufficient evidence existed to ethically alter practice (Sage 2003).
Despite that 2003 Best Bets review, several decades of research imply that using clean, dry, non-sterile gloves (or no gloves) in acute care settings do not increase post-repair infection rates. In fact, in 1982 Bodiwala et al. observed no increase in infection rates for 418 laceration repairs using bare hand (no glove) wound repair when comparing surgical gloves (207 wounds) with no gloves (210 wounds). Similarly, another study in the mid-1980’s using bare hands for 25 patients and surgical gloves for 25 patients did not increase the incidence of complications in rural primary care (Worrall 1987). In this month’s Journal club we critically appraised two ED-based studies, one primary care study, and a surgery study, each of which evaluated the risk of post-wound repair infection using non-sterile, clean gloves.
A three hospital, Toronto ED-based, randomized controlled study which is both the most pertinent and the highest quality research to date on the topic of ED wound closure. The authors excluded 26% of patients with diabetes, renal failure, asplenia, immunodeficiency (acquired, congenital or immunosuppressive therapy), cirrhosis, keloids, current antibiotic use, treating physician perspective that prophylactic antibiotics were required (prosthetic heart valve, bites, contaminated wounds), high risk wounds (multiple trauma, open fracture, concomitant vascular, nerve or tendon injury, stab wounds, gunshot wounds, intra-articular wounds, animal and human bites, presentations >12 hours after injury, signs of infection at presentation, or suspected foreign body), or those who did not consent. They used explicit, previously defined criteria to define “wound infection” (Maitra 1986, Rutherford 1980, Gosnold 1977), cultured purulent infections at follow-up, and noted no increased risk of infection using non-sterile gloves. Critical concerns for this study that might limit confidence in the results included lack of reporting of physician-level characteristics (experience closing wounds), patient-level characteristics (health literacy, socioeconomic status), or system-level characteristics (access to primary care for follow-up wound care).
This Iranian ED study was deemed too biased with incomplete statistical analysis to meaningfully inform the equivalency or non-inferiority of non-sterile gloves for traumatic, contaminated wound closure. Among the many flaws identified were
· No blinding so significant potential for bias (skewed estimates of “truth” in observed outcomes) with biases by patients (ascertainment bias by better follow-up), physicians (co-intervention bias), or outcome assessors.
· High lost to follow-up rates without any sensitivity analysis to explore the potential effect on results if those lost to follow-up developed wound infections.
· No regression analysis to determine whether unequal distribution of confounders (age, limb, wound, sharp objects) accounted for differences in wound infection rate rather than sterile vs. non-sterile gloves.
· No standardization of either wound repair (Irrigation? Topical antibiotic?) or how to reproducibly define if “wound infection” occurred.
· Uncertain external validity to U.S. EDs (staffing of EDs, availability of outpatient follow-up).
· No assessment of patient compliance with oral antibiotics.
· No sample size calculation to quantify the risks of Type I and Type II error.
· No confidence intervals presented so unable to assess precision.
This Australian primary care study evaluated skin biopsies with suture repair noting no association between non-sterile glove use and skin infection rates at the time of suture removal. These results should be extrapolated to ED traumatic incisions cautiously, since trauma-related incisions requiring suture repair are often contaminated, irregular, and closed several hours after skin opening.
This Dermatology-surgeon study had limited applicability to ED laceration repairs: one surgeon performing thousands of Mohs Micrographic Surgery procedures did not detect significant change in SSI when using NSG. This has limited application to the average ED where many physicians repair traumatic lacerations that are frequently irregular, deep and contaminated. In additional, multiple flaws in this study included
· No randomization or blinding so subject to observational trial bias.
· No explicit definition of “wound infection” (for examples see Maitra 1986, Rutherford 1980, or Gosnold 1977) which could affect both the accuracy and the reliability of whether wound infection was present or absent.
· Limited external validity to surgeons (only 1 surgeon performed every procedure) and to emergency medicine (different patients, different environment, and different injuries then Dermatology patients) so this is essentially an “N of 1” study for that surgeon.
· Uncertain lost to follow-up.
· No explicit methods for logistic regression (inclusion criteria, goodness of fit).
General concerns expressed by Journal Club attendees included
1) Fear of a “slippery slope effect” in ED procedures beginning with appropriate non-sterile glove use for immunocompetent, low-risk patients and then extrapolating this to non-sterile use on higher risk patients and/or inappropriate (non-evidence based) use with lumbar punctures and central lines. The consensus opinion was that is the role for clinical educator oversight, bedside procedural teaching, and trainee (and attending) understanding of the published research.
2) Uncertain role for Shared Decision Making between clinicians and patients regarding the use of non-sterile gloves for wound repair in appropriate patients. There was no consensus on this debate, but hope that the 2016 AEM Consensus Conference would better highlight appropriate scenarios for ED Shared Decision Making. However, there was consensus that if a clinician decides to use non-sterile gloves and a patient or family member asks why non-sterile gloves are being used that the provider should be able to explain the rationale and safety for this decision based on the available evidence.
3) Several attendees debated the true cost-savings of this penny pinching discussion since much more expensive decisions are made daily in every ED, ward, and ICU. However, most attendees felt that with the volume of laceration repairs occurring in most EDs with frequent task interruptions necessitating gloves to be changed in an era of transparent cost-containment, using non-sterile gloves on immunocompetent patients with low risk wounds is worth considering.
Despite these concerns, the vast majority of attendees felt comfortable using non-sterile gloves for low-risk laceration repairs. In fact, most already were using non-sterile gloves based on their awareness on this topic from the social media world.