The ability to understand or “read” lower-extremity redness in your patient is essential to determining its cause and providing effective treatment. Redness can occur in multiple conditions—hemosiderin staining, lipodermatosclerosis, venous dermatitis, chronic inflammation, cellulitis, and dependent rubor. This article provides clues to help you differentiate these conditions and identify the specific cause of your patient’s lower-extremity redness. (more…)
To begin appropriate treatment for chronic venous insufficiency (CVI), clinicians must be able to make the correct diagnosis. Part 1 (published in the March-April edition) described CVI and its presentation. This article provides details of the CVI diagnosis (including the differential diagnosis from other diseases), disease classification to help assess the extent of CVI, diagnostic studies used to diagnose CVI, and various treatment options to “rescue” the patient from CVI. (more…)
Chronic venous insufficiency (CVI) is the most common cause of lower extremity wounds. The venous tree is defective, incapable of moving all the blood from the lower extremity back to the heart. This causes pooling of blood and intravascular fluid at the lowest gravitational point of the body—the ankle.
This article has two parts. Part 1 enhances your understanding of the disease and its clinical presentation. Part 2, which will appear in a later issue, explores the differential diagnosis of similar common diseases, the role that coexisting peripheral artery disease (PAD) may play, disease classification of venous insufficiency, and a general approach to therapy.
The most common form of lower extremity vascular disease, CVI affects 6 to 7 million people in the United States. Incidence increases with age and other risk factors. One study of 600 patients with CVI ulcers revealed that 50% had these ulcers for 7 to 9 months, 8% to 34% had them for more than 5 years, and 75% had recurrent ulcers.
Thrombotic complications of CVI include thrombophlebitis, which may range from superficial to extensive. If the thrombophlebitis extends up toward the common femoral vein leaving the leg, proximal ligation may be needed to prevent clot extension or embolization.
Understanding normal anatomy and physiology
Lower extremity veins flow horizontally from the superficial veins to the perforating veins and then into the deep veins. Normally, overall venous blood flows vertically against gravity from the foot and ankle upward toward the inferior vena cava (IVC). This antigravity flow toward the IVC results from muscular contraction around nonobstructed veins and one-way valves that close as blood passes them. These valves prevent abnormal backward blood flow toward the foot and ankle region.
The lower extremities have four types of veins. Superficial veins are located within the subcutaneous tissue between the dermis and muscular fascia. Examples are the greater and lesser (smaller) saphenous veins. Perforating veins connect the superficial veins to the deep veins of the leg. The deep veins are located below the muscular fascia. The communicating veins connect veins within the same system.
The greater saphenous vein is on the leg’s medial (inner) side. It originates from the dorsal veins on top of the foot and eventually drains into the common femoral vein in the groin region. By way of perforating veins, the greater saphenous vein drains into the deep venous system of both the calf and thigh.
The lesser saphenous vein is situated on the lateral (outer) side of the leg and originates from the lateral foot veins. As it ascends, it drains into the deep system at the popliteal vein behind the knee. Communicating veins connect the greater saphenous vein medially and the lesser saphenous vein laterally.
Intramuscular veins are the deep veins within the muscle itself, while the intermuscular veins are located between the muscle groups. The intermuscular veins are more important than other veins in development of chronic venous disease. Below the knee, the intermuscular veins are paired and take on the name of the artery they accompany—for example, paired anterior tibial, paired posterior tibial, and paired peroneal veins. Eventually, these veins form the popliteal vein behind the knee, which ultimately drains into the femoral vein of the groin.
As the common femoral vein travels below the inguinal ligament of the groin, it’s called the external iliac vein. Eventually, it becomes the common iliac vein, which drains directly into the IVC.
Pathophysiology
Abnormally elevated venous pressure stems from the leg’s inability to adequately drain blood from the leg toward the heart. Blood drainage from the leg requires the muscular pumping action of the leg onto the veins, which pump blood from the leg toward the heart as well as from the superficial veins toward the deep veins. Functioning one-way valves within the veins close when blood passes them, preventing blood from flowing backward toward the ankle. This process resembles what happens when you climb a ladder with intact rungs: As you step up from one rung to the next, you’re able to ascend.
CVI and the “broken rung” analogy
If the one-way valves are damaged or incompetent, the “broken rung” situation occurs. Think how hard it would be to climb a ladder with broken rungs: You might be able to ascend the ladder, but probably you would fall downward off the ladder due to the defective, broken rungs.
Normally, one-way valves ensure that blood flows from the lower leg toward the IVC and that the superficial venous system flows toward the deep venous system. The venous system must be patent (open) so blood flowing from the leg can flow upward toward the IVC. Blockage of a vein may result from an acute thrombosis (clot) in the superficial or deep systems. With time, blood may be rerouted around an obstructed vein. If the acute thrombosis involves one or more of the one-way valves, as the obstructing thrombosis opens up within the vein’s lumen, permanent valvular damage may occur, leading to post-thrombotic syndrome—a form of CVI.
CVI may result from an abnormality of any or all of the processes needed to drain blood from the leg—poor pumping action of the leg muscles, damage to the one-way valves, and blockage in the venous system. CVI commonly causes venous hypertension due to reversal of blood flow in the leg. Such abnormal flow may cause one or more of the following local effects:
leg swelling
tissue anoxia, inflammation, or necrosis
subcutaneous fibrosis
Compromised flow of venous blood or lymphatic fluid from the extremity.
“Water balloon” analogy
The effect of elevated venous pressure or hypertension is worst at the lowest gravitational point (around the ankle). Pooling of blood and intravascular fluid around the ankle causes a “water balloon” effect. A balloon inflated with water has a thin, easily traumatized wall. When it bursts, a large volume of fluid drains out. Due to its thicker wall, a collapsed balloon that contains less fluid is more difficult to break than one distended with water.
In a leg with CVI, subcutaneous fluid that builds up requires a weaker force to break the skin and ulcerate than does a nondistended leg with less fluid. This principle is the basis for compression therapy in treating and preventing CVI ulcers.
Effects of elevated venous pressure or hypertension
Increased pressure in the venous system causes:
abnormally high pressure in the superficial veins—60 to 90 mm Hg, compared to the normal pressure of 20 to 30 mm Hg
dilation and distortion of leg veins, because blood refluxes abnormally away from the heart and toward the lower leg and may move from the deep venous system into the superficial veins.
Abnormal vein swelling from elevated pressure in itself may impair an already abnormally functioning one-way valve. For instance, the valve may become more displaced due to the increase in intraluminal fluid, which may in turn worsen hypertension and cause an increase in leg swelling. Increased pressure from swollen veins also may dilate the capillary beds that drain into the veins; this may cause leakage of fluid and red blood cells from capillaries into the interstitial space, exacerbating leg swelling. Also, increased venous pressure may cause fibrinogen to leak from the intravascular plasma into the interstitial space. This leakage may create a fibrin cuff around the capillary bed, which may decrease the amount of oxygen entering the epidermis, increase tissue hypoxia, trigger leukocyte activation, increase capillary permeability, and cause local inflammation. These changes may lead to ulceration, lipodermatosclerosis, or both.
Visible changes may include dilated superficial veins, hemosiderin staining due to blood leakage from the venous tree, atrophie blanche, and lipodermatosclerosis. (See CVI glossary by clicking the PDF icon above.) Both atrophie blanche and lipodermatosclerosis result from local tissue scarring secondary to an inflammatory reaction of the leg distended with fluid.
Lipodermatosclerosis refers to scarring of subcutaneous tissue in severe venous insufficiency. Induration is associated with inflammation, which can cause the skin to bind to the subcutaneous tissue, causing narrowing of leg circumference. Lymphatic flow from the leg also may become compromised and inhibited in severe venous hypertension, causing additional leg swelling.
Patient history
In a patient with known or suspected CVI, a thorough history may lead to a working diagnosis. Be sure to ask the patient these questions:
Do you have pain?
Is your pain worse toward the end of the day?
Is the pain relieved with leg elevation at night?
Is it relieved with leg elevation during the day?
Do you have leg pain that awakens you at night?
How would you describe the pain?
Does the skin on your leg feel tight or irritated?
Have you noticed visible changes of your leg?
Do you have a leg ulcer?
Also determine if the patient has comorbidities that may exacerbate CVI, including PAD, renal failure, venous thrombosis, lymphedema, diabetes mellitus, heart failure, or malnutrition. (See CVI risk factors by clicking the PDF icon above .)
Common CVI symptoms
Approximately 20% of CVI patients have symptoms of the disease without physical findings. These symptoms may include:
tired, “heavy” legs that feel worse toward the end of the day
discomfort that worsens on standing
legs that feel best in the morning after sleeping or after the legs have been
elevated during the day.
Although patients may report leg discomfort, the history indicates that it doesn’t awaken them at night. Be aware that discomfort from CVI differs from that caused by PAD. With PAD, patients may report pain on exercise (claudication), pain with elevation (nocturnal pain), or constant pain (resting pain).
Signs of CVI (with or without ulcers) include:
leg swelling (seen in 25% to 75% of patients)
skin changes (such as hemosiderin staining or dermatitis)
telangiectasia, reticular veins, or both; while these are the most common signs, they represent an overall less severe finding
varicose veins with or without bleeding, occurring in one-third of patients with CVI.
Venous ulcers
Venous ulcers are the most common type of lower extremity ulcer. They’re commonly found on the medial aspect of the lower extremity, from the ankle to the more proximal calf area. Usually, they arise along the course of the greater saphenous vein, but also may be lateral and may occur at multiple locations. They aren’t found above the knee or on the forefoot. Venous ulcers are shallower than arterial ulcers and have considerable exudate consistent with drainage from a ruptured water balloon. They may extend completely around the leg.
CVI: From a heavy sensation to visible changes
In patients with CVI, blood flows within a lower extremity in an abnormal, reverse direction, causing build-up of blood and intravascular fluid around the ankle. Initially, this may cause only a sensation of heavy legs toward the end of the day, with no visible changes. Eventually, it may lead to venous ulcers or other visible changes. This abnormal blood flow results from dysfunction of the normal mechanisms that drain blood from the leg against gravity into the IVC.
Sardina D. Skin and Wound Management Course; Seminar Workbook. Wound Care Education Institute; 2011:92-112.
Donald A. Wollheim is a practicing wound care physician in southeastern Wisconsin. He also is an instructor for Wound Care Education Institute and Madison College. He serves on the Editorial Board for Wound Care Advisor.
The number of people with diabetes who are meeting the ABC goals—hemoglobin A1C, blood pressure, and LDL cholesterol—has risen significantly in recent years, according to a study published by Diabetes Care. Patients meeting all three goals rose from about 2% in 1988 to about 19% in 2010.
Gains were made in each of the ABC goals, based on 2007 to 2010 data: 53% of patients met A1C goals, compared to 43% in 1988 to 1994 data; 51% met blood pressure goals, compared to 33%; and 56% met LDL goals, compared to 10%.
Younger people were less likely to meet A1C and cholesterol goals. Compared with non-
Hispanic whites, Mexican Americans were less likely to meet A1C and LDL goals and non-Hispanic blacks were less likely to meet blood pressure and LDL goals.
The researchers analyzed data from the National Health and Nutrition Examination Surveys from 1988–1994, 1999–2002, 2003–2006, and 2007–2010. Nearly 5,000 people age 20 or older participated.
Although progress had been made, the researchers conclude, “Despite significant improvement during the past decade, achieving the ABC goals remains suboptimal among adults with diabetes, particularly in some minority groups.”
Daily bathing with chlorhexidine-impregnated washcloths reduces infection risk
A study in The New England Journal of Medicine reports that daily bathing with chlorhexidine-impregnated washcloths reduces the risk of becoming infected with multidrug-resistant organisms and subsequent development of hospital-acquired bloodstream infections in intensive care unit patients.
“Effect of daily chlorhexidine bathing on hospital-acquired infection” included 7,727 patients in nine intensive care and bone marrow units in six hospitals. The units were randomly assigned to bathe patients with either no-rinse 2% chlorhexidine-impregnated washcloths or nonantimicrobial washcloths for 6 months; then, the units switched to the opposite product for 6 months.
The rate of infection with multidrug-resistant organisms was 23% lower in the chlorhexidine group and the rate of hospital-acquired bloodstream infection was 28% lower in the chlorhexidine group.
Patients tend not to wear custom-made footwear for preventing diabetic foot ulcers
Adherence to wearing prescription custom-made footwear was low among patients with diabetes, neuropathy, and a recently healed plantar foot ulcer, according to a study in Diabetes Care. The low adherence was particularly notable at home, where patients did the most walking.
Factors associated with higher adherence included lower body mass index, more severe foot deformity, and more appealing footwear.
Tedizolid works as well as linezolid in patients with acute bacterial skin infections
A JAMA study says that a 200-mg once-daily dose of oral tedizolid phosphate over 6 days was as effective as 600 mg of oral linezolid every 12 hours for 10 days in patients with acute bacterial skin and skin-structure infections, including cellulitis or erysipelas, major cutaneous abscesses, and wound infections.
A shorter course of tedizolid may be a “reasonable alternative” to linezolid for treating acute bacterial skin and skin-structure infections, the study concludes.
Water-based exercise improves ROM in patients with long-term arm lymphedema
A study of breast cancer survivors (median 10 years after surgery) with lymphedema found that a water-based exercise program improved shoulder range of motion (ROM).
The program consisted of at least twice-weekly water-based exercise for 8 weeks. At first, participants were supervised, but later they exercised independently. Although lymphedema status didn’t change, those who performed water-based exercise had an increase in ROM, showing improvement years after surgery.
Dehydrated amniotic membrane allograft possible option for treating chronic wounds
A dehydrated amniotic membrane allograft (EpiFix) was used to treat four patients whose wounds hadn’t closed after conservative and advanced measures and who had been referred for plastic procedures. A variety of wounds healed (located on the elbow, knee, hand, and ankle) after one to three applications of the amniotic material, which patients tolerated well. The wounds remained closed several months later.
Study casts doubt on MLD’s role in breast cancer–related lymphedema
A meta-analysis published in the World Journal of Surgical Oncology found the “current evidence” from randomized clinical trials “does not support” the use of manual lymphatic drainage (MLD) in preventing or treating lymphedema in patients with breast cancer.
The authors analyzed 10 randomized clinical trials with 566 patients.
CDC issues additional prevention steps for carbapenem-resistant Enterobacteriaceae
On Feb. 14, the Centers for Disease Control and Prevention (CDC) issued additional prevention steps for carbapenem-resistant Enterobacteriaceae (CRE). Increased reports of CRE prompted the action: Of the 37 unusual forms of CRE reported in the U.S., the last 15 have been reported since July 2012.
• When a CRE is identified in a patient with a history of an overnight stay in a healthcare facility (within the last 6 months) outside the U.S., send the isolate to a reference laboratory for confirmatory susceptibility testing and test to determine the carbapenem resistance mechanism.
• For patients admitted to healthcare facilities in the U.S. after recently being hospitalized (within the last 6 months) in countries outside the U.S., consider performing rectal screening cultures to detect CRE colonization, and place patients on contact precautions while awaiting the results.
Examples of Enterobacteriaceae include Klebsiella species and Escherichia coli. CRE are Enterobacteriaceae with high levels of resistance to antibiotics, including carbapenems. CRE infections most commonly occur among patients who are receiving antibiotics and significant medical treatment for other conditions.
In a busy wound clinic, quick and accurate differential diagnosis of edema is essential to appropriate treatment or referral for comprehensive care. According to a 2010 article in American Family Physician, 80% of lower extremity ulcers result from chronic venous insufficiency (CVI). In 2007, the German Bonn Vein Study found 100% of participants with active venous ulcers also had a positive Stemmer’s sign, indicating lymphedema. (more…)
By Carrie Carls, BSN, RN, CWOCN, CHRN; Michael Molyneaux, MD; and William Ryan, CHT
Every year, 1.9% of patients with diabetes develop foot ulcers. Of those, 15% to 20% undergo an amputation within 5 years of ulcer onset. During their lifetimes, an estimated 25% of diabetic patients develop a foot ulcer. This article discusses use of hyperbaric oxygen therapy (HBOT) in treating diabetic foot ulcers, presenting several case studies.
HBOT involves intermittent administration of 100% oxygen inhaled at a pressure greater than sea level. It may be given in a:
• multi-place chamber (used to treat multiple patients at the same time), compressed to depth by air as the patient breathes 100% oxygen through a face mask or hood (more…)
Staphylococcus aureus is one of the most feared human pathogens, causing a wide range of infections. Most wound care professionals can expect to frequently encounter patients with S. aureus infections. Soft-tissue infections caused by S. aureus include impetigo, cellulitis, and cutaneous abscesses, as well as such life-threatening processes as necrotizing fasciitis and pyomyositis (a hematogenous intramuscular abscess). Serious non-soft-tissue infections include septic arthritis, osteomyelitis, pneumonia, endocarditis, and sepsis.
Why is S. aureus such a nasty bug?
S. aureus produces various cellular and extracellular factors involved in the pathogenesis of infection. S. aureus protein A, an important surface protein, helps the organism resist phagocytosis. Also, S. aureus produces several cytotoxins and enzymes that contribute to infection spread and severity. In addition, some strains produce toxins (including toxic shock syndrome toxin-1) that function as superantigens—molecules that nonspecifically trigger release of large amounts of cytokines, leading to a sepsislike condition. Taken together, such factors combine to make S. aureus a dangerous pathogen.
MRSA emergence
When penicillin was introduced in the 1940s, virtually all S. aureus isolates were sensitive to that drug. But soon thereafter, S. aureus strains that produced a β-lactamase enzyme capable of inactivating penicillin became widespread. During the 1950s, outbreaks of penicillin-resistant S. aureus occurred in many U.S. hospitals. Introduction of penicillinase-resistant antibiotics, such as methicillin and oxacillin, temporarily restored the ability to treat all strains of this pathogen using penicillin antibiotics. The first strain of methicillin-resistant S. aureus (MRSA) was described in 1961 shortly after introduction of penicillinase-resistant antibiotics.
The mechanism of methicillin resistance involves a mutation in one of the bacterial cell-wall proteins to which penicillins must bind to kill the bacterium. This mutation renders the organism resistant to all penicillins and penems and almost all cephalosporins.
MRSA incidence has increased steadily to the point where it currently constitutes up to 60% of S. aureus isolates in many U.S. hospitals. These organisms commonly carry genetic material that makes them resistant to various non-β lactam antibiotics as well, leading some to suggest that the term MRSA should stand for multiply resistant S. aureus. S. aureus has continued to mutate in the face of persistent antibiotic pressure. Vancomycin-intermediate S. aureus (VISA) was described in 1997; vancomycin-resistant S. aureus (VRSA), in 2003. Fortunately, these two strains remain rare and haven’t become established pathogens. (See Strains of antibiotic-resistantS. aureus by clicking the PDF icon above.)
Healthcare- versus community-acquired MRSA
Although MRSA initially arose and spread within healthcare settings (chiefly acute-care hospitals), a community-based variant was described in 1998. Called community-
acquired MRSA (CA-MRSA), this variant differs from healthcare-associated MRSA (HCA-MRSA) in more ways than the acquisition site. CA-MRSA occurs predominately in otherwise healthy children and young adults.
It most commonly presents as recurrent cutaneous abscesses, although life-threatening infections (such as necrotizing fasciitis and pneumonia) also have occurred. The propensity to cause cutaneous abscesses isn’t fully understood but may relate partly to production of the Panton-Valentine toxin by many CA-MRSA isolates.
In contrast, HCA-MRSA afflicts mainly older patients, particularly those with chronic illnesses, including chronic wounds. It typically causes wound infections, urinary tract infections, pneumonia, and bacteremia.
Besides these epidemiologic and clinical differences, many CA-MRSA isolates derive from a single clone, known as clone USA 300, whereas HCA-MRSA is composed of multiple non-USA 300 clones. Finally, many CA-MRSA isolates are sensitive to non-β
lactam antibiotics, whereas most HCA-MRSA isolates resist multiple antibiotics. More recently, the distinction between CA-MRSA and HCA-MRSA has been blurred as evidence emerges that CA-MRSA now is being transmitted in healthcare settings as well as in the community.
S. aureus carrier state
Staphylococci are frequent colonizers of humans. Common colonization sites include the skin, anterior nares, axillae, and inguinal regions. Individuals can be colonized continuously or transiently, with nasal carriage rates varying from 20% to 40%. Most S. aureus infections result from the strain carried by the infected patient.
Three patterns of S. aureus carriage exist in humans:
• 20% of individuals are continuously colonized.
• 30% of individuals are intermittently colonized.
• 50% of individuals are never colonized.
The highest carriage rates occur in patients receiving frequent injections (such as insulin-dependent diabetics, hemodialysis patients, and I.V. drug users) and those with chronic skin conditions (for instance, psoriasis or eczema). In the general population, MRSA carriage rates have increased to 1% or 2%, with clinical consequences hinging on the colonizing strain (CA-MRSA versus HCA-MRSA) and host characteristics. The most consistent carriage site is the anterior nares, but many other sites may carry this pathogen, including the axillae, inguinal regions, and perirectal area.
MRSA treatment
Therapy for MRSA infection depends on the infection location and antibiotic sensitivity of the infecting strain.
• Cutaneous abscesses are treated by incision and drainage; antibiotics play a secondary role to adequate drainage.
• Therapy for necrotizing fasciitis caused by MRSA involves aggressive debridement with removal of all necrotic tissue, plus adequate antibiotic therapy. Typically, patients require serial debridement followed by subsequent careful wound care, often with eventual skin grafting.
• Pyomyositis treatment entails drainage of the muscle abscess (which sometimes can be done with percutaneous tube placement instead of open drainage), plus appropriate antibiotic therapy.
Vancomycin has been the mainstay of I.V. therapy for MRSA for decades, but some clinicians are concerned that its effectiveness may be declining due to slowly increasing minimum inhibitory concentrations (the minimum concentration of an
antibiotic needed to inhibit pathogen growth). Other parenteral options have emerged in the last few years. (See I.V. drugs used to treat MRSA by clicking the PDF icon above.) Several oral antibiotics also are available for MRSA treatment. (See Oral agents used to treat MRSA by clicking the PDF icon above.)
Knowing the antibiotic sensitivity pattern of the infecting MRSA strain is crucial to ensuring that the patient receives an appropriate antibiotic. Treatment duration for soft-
tissue infections usually ranges from 7 to 14 days, but bacteremia and bone or joint infections call for more prolonged therapy.
Efforts to eradicate MRSA carriage
Because the carrier state increases the risk of subsequent S. aureus infection, efforts have been made to eradicate carriage. Unfortunately, this has proven to be difficult. A commonly used regimen involves 5 days of twice-daily mupirocin nasal ointment with either chlorhexidine gluconate showers or immersion up to the neck in a dilute bleach solution. However, success in eliminating carriage is limited, although the bleach bath seems to improve eradication rates better than other modalities.
Controlling MRSA in hospitals
How best to control MRSA spread within hospitals is controversial. Some experts advocate an aggressive, “search and destroy” approach involving screening all patients for nasal carriage on admission and initiating contact precautions with subsequent decolonization efforts. Others focus on improving the overall level of hand hygiene and other general infection-control measures, arguing that nasal screening misses at least 20% of MRSA-colonized patients and thus gives an unwarranted sense of security.
Many hospitals use a mixed approach, screening patients suspected to be at high risk for MRSA carriage (such as those admitted from extended-care facilities or to the intensive care unit), while simultaneously trying to improve hand hygiene and general infection-control measures. Recent data suggest MRSA colonization and infection rates have stopped increasing and are beginning to decline.
MRSA is one of the most problematic pathogens encountered on a regular basis, and among the most dangerous pathogens we face. While some MRSA infections are relatively mild, many are serious or life-threatening. Severe soft-tissue infections, such as necrotizing fasciitis and pyomyositis, require surgical debridement or drainage, appropriate antibiotic therapy, and assistance from a wound-care professional to achieve optimal outcomes. n
Selected references
Calfee DP. The epidemiology, treatment and prevention of transmission of methicillin-resistant Staphylococcus aureus. J Infus Nurs. 2011 Nov-Dec;34(6):359-64.
DeLeo FR, Otto M, Kreiswirth BN, Chambers HF. Community-associated meticillin-resistant Staphylococcus aureus. Lancet. 2010 May 1;375(9725): 1557-68.
Ippolito G, Leone S, Lauria FN, et al. Methicillin-resistant Staphylococcus aureus: the superbug. Int J Infect Dis. 2010 Oct;14 Suppl 4:S7-11.
Landrum ML, Neumann C, Cook C, et al. Epidemiology of Staphylococcus aureus blood and skin and soft tissue infections in the US military health system, 2005-2010. JAMA. July 4;308:50-9.
Lee AS, Huttner B, Harbarth S. Control of methicillin-resistant Staphylococcus aureus. Infect Dis Clin North Am. 2011 Mar;25(1):155-79.
Moellering RC Jr. MRSA: the first half century. J Antimicrob Chemother. 2012 Jan;67(1):4-11.
Otter JA, French GL. Community-associated meticillin-resistant Staphylococcus aureus strains as a cause of healthcare-associated infection. J Hosp Infect. 2011 Nov:79(3):189-93.
Rivera AM, Boucher HW. Current concepts in antimicrobial therapy against select gram-positive organisms: methicillin-resistant Staphylococcus aureus, penicillin-resistant pneumococci, and vancomycin-resistant enterococci. Mayo Clin Proc. 2011 Dec;86(12):1230-43.
Simor AE. Staphylococcal decolonization: an effective strategy for prevention of infection? Lancet Infect Dis. 2011 Dec;11(12):952-62.
Joseph G. Garner is director of the infectious disease division and hospital epidemiologist at the Hospital of Central Connecticut and a professor of medicine at the University of Connecticut.
New wound-swabbing technique detects more bacteria
The new Essen Rotary swabbing technique takes a few seconds longer to perform than traditional techniques, but improves bacterial count accuracy in patients with chronic leg ulcers, according to a study published by Wounds International.
“Evaluation of the Essen Rotary as a new technique for bacterial swabs: Results of a prospective controlled clinical investigation in 50 patients with chronic leg ulcers” reports that Essen Rotary detected significantly more bacteria compared to standard techniques and was the only one to identify five patients with methicillin-resistant Staphylococcus aureus (MRSA), compared to three detected by other techniques.
The Essen Rotary technique samples a larger surface area of the wound, which is beneficial for detecting MRSA.
“The Essen Rotary may become the new gold standard in routinely taken bacteriological swabs especially for MRSA screenings in patients with chronic leg ulcers,” the study authors write.
Reducing HbA1c by less than 1% cuts cardiovascular risk by 45% in patients with type 2 diabetes
A study presented at the American Diabetes Association 72nd Scientific Sessions found lowering HbA1c an average of 0.8% (from a mean of 7.8% to 7.0%, the treatment target) reduced the risk of cardiovascular death by 45% in patients with type
2 diabetes.
The absolute risk of mortality from a cardiovascular event was 9.9 events per 1,000 person-years in patients with decreasing HbA1c compared to 17.8 events in patients with stable or increasing HbA1c.
“HbA1c reduction and risk of cardiovascular diseases in type 2 diabetes: An observational study from the Swedish NDR” examined data from 18,035 patients in the Swedish National Diabetes Register.
CMS revises hospital, nursing home comparison websites
The Centers for Medicare & Medicaid Services (CMS) has enhanced two websites designed to help the public make informed choices about their health care. Hospital Compare and Nursing Home Compare now have better navigation and new comparison tools. The two sites include data on quality measures, such as frequency of hospital-acquired infections, and allow the user to compare hospitals on these measures.
Improvements include easy-to-use maps for locating hospitals, a new search function that enables the user to input the name of a hospital, and glossaries that are easier to understand. It’s now also possible to access the data on the sites through mobile applications.
CMS maintains the websites, which are helpful for anyone who wants to compare facilities, not just patients on Medicare or Medicaid.
For more information, read the article in Healthcare IT News.
IOM releases report on accelerating new drug and diagnostics development
The Institute of Medicine (IOM) released “Accelerating the development of new drugs and diagnostics: Maximizing the impact of the Cures Acceleration Network—Workshop Summary.” The report is a summary of a forum that brought together members of federal government agencies, the private sector, academia, and advocacy groups to explore options and opportunities in the implementation of Cures Acceleration Network (CAN). The newly developed CAN has the potential to stimulate widespread changes in the National Institutes of Health and drug development in general.
Focus on individualized care—not just reducing swelling—in lymphedema patients
As a result of two extensive literature reviews, a researcher at the University of Missouri found that emphasizing quality of life—not just reducing swelling—is important for patients with lymphedema. Many providers and insurance companies base treatment on the degree of edema, but the volume of fluid doesn’t always correspond with the patients’ discomfort. Instead, an individualized plan of care should be developed.
The researchers found that Complete Decongestive Therapy (CDT), a comprehensive approach for treating lymphedema that includes skin and nail care, exercise, manual lymphatic drainage, and compression, may be the best form of specialized lymphedema management. For more information about CDT, watch for the November/December issue of Wound Care Advisor.
Plague case in Oregon draws national attention
An article about a case of the plague in Oregon has appeared on Huffington Post. A welder contracted the disease as a result of unsuccessfully removing a mouse from a stray cat’s mouth. Part of his hands have, in the words of the article, “darkened to the color of charcoal.” Later tests confirmed the cat had the plague.
Plague cases are rare in the United States. According to the Centers for Disease Control and Prevention, an average of 7 human cases are reported each year, with a range of 1 to 17 cases. Antibiotics have significantly reduced morality. About half of cases occur in people ages 12 to 45.
Use of negative pressure wound therapy with skin grafts
“Optimal use of negative pressure wound therapy for skin grafts,” published by International Wound Journal, reviews expert opinion and scientific evidence related to the use of negative pressure wound therapy with reticulated open-cell foam for securing split-thickness skin grafts.
The article covers wound preparation, treatment criteria and goals, economic value, and case studies. The authors conclude that the therapy has many benefits, but note that future studies are needed “to better measure the expanding treatment goals associated with graft care, including increased patient satisfaction, increased patience compliance and improved clinical outcomes.”
Mechanism for halting healing of venous ulcers identified
Researchers have identified that aberrantly expressed microRNAs inhibit healing of chronic venous ulcers, according to a study in The Journal of Biological Chemistry.
Six microRNAs were plentiful in 10 patients with chronic venous ulcers. The microRNAs target genes important in healing the ulcers. In an article about the study, one of the researchers said, “The more we know about the molecular mechanisms that contribute to [the development of venous ulcers], the more we can rationally develop both diagnostic tools and new therapies.”
Hemodialysis-related foot ulcers not limited to patients with diabetes
Both patients with diabetes and those without are at risk for hemodialysis-related foot ulcers, according to a study published by International Wound Journal.
Researchers assessed 57 patients for ulcer risk factors (peripheral neuropathy, peripheral arterial disease, and foot pathology, such as claw toes, hallux valgus, prominent metatarsal heads, corns, callosities, and nail pathologies) at baseline, and noted mortality 3 years later.
In all, 79% of patients had foot pathology at baseline, and 18% of patients without diabetes had peripheral neuropathy. Peripheral arterial disease was present in 45% of diabetic and 30% of nondiabetic patients. Nearly half (49%) of patients had two or more risk factors. Only 12% of patients had no risk factors. The presence of peripheral arterial disease and peripheral neuropathy increased risk of mortality.
The authors of “Prevalence of risk factors for foot ulceration in a general haemodialysis population” state that the high prevalence of risk factors in nondiabetic patients indicates that they are at risk for developing foot ulcers.
Study identifies risk factors for mortality from MRSA bacteremia
A study in Emerging Infectious Diseases found that older age, living in a nursing home, severe bacteremia, and organ impairment increase the risk of death from methicillin-resistant Staphylococcus aureus (MRSA) bacteremia.
Consultation with a specialist in infectious disease lowers the risk of death, and MRSA strain types weren’t associated with mortality.
“Predicting risk for death from MRSA bacteremia” studied 699 incidents of blood infection from 603 patients who had MRSA bacteremia.
Necrotizing fasciitis (NF) results from an infection that attacks the fascia and subcutaneous tissues. The primary bacterial etiology is group A streptococcus, a facultative anaerobic bacterium. However, other bacteria may contribute. Sometimes called the “flesh-eating” disease because of the potentially devastating effect on the afflicted patient, NF can be monomicrobial or polymicrobial.
The four typical settings for NF are:
surgical bowel or abdominal trauma surgery
pressure ulcer and perianal abscess
injection sites (especially in drug users)
Bartholin abscess or minor vulvovaginal infection.
Because of the rapid course and ravaging nature of acute NF, clinicians must maintain a high index of suspicion if the patient has suggestive signs and symptoms. In 1990, puppeteer Jim Henson (best known for creating the Muppets) died from NF. At that time, little was known about the progression of group A streptococcal infection.
The disease can quickly cause death, so starting immediate treatment is even more crucial than confirming the diagnosis. Once the disease is suspected, antibiotics must be given immediately and the patient must be prepared for surgery at once. NF spreads rapidly, capable of progressing from a small lesion to death in days to weeks. Thus, delayed diagnosis increases the risk of death. Lack of knowledge about the disease and inability to recognize it promptly are the main reasons many victims die. This article can improve your knowledge base.
Overview
NF was discovered in 1871 by Joseph Jones, a Confederate Army surgeon. At that time, it was called hemolytic streptococcal gangrene, nonclostridial gas gangrene, nonclostridial crepitant cellulitis, necrotizing or gangrenous erysipelas, necrotizing cellulitis, bacterial synergistic gangrene, or synergistic necrotizing cellulitis.
NF involves the fascia, muscle compartments, or both. It can affect not only the muscle fascia but the superficial fascia. NF and cellulitis differ in the amount of tissue involved and extent of tissue involvement.
The most common areas of infection are the abdominal wall, perineum, and extremities. When NF affects the perineum and scrotum, it’s called Fournier gangrene, after the French dermatologist and virologist Alfred Jean Fournier.
The most common causes are trauma, surgery, and insect bites. The disease can affect persons of any age. Such comorbidities as diabetes, chronic renal failure, immunosuppressive therapy, hypertension, obesity, and malnutrition increase susceptibility.
Pathophysiology
NF falls into four classifications based on wound microbiology. Type 1, the most common, involves polymicrobial bacteria. Type 2 results from trauma and is associated with comorbidities. Type 3, rare in this country, stems from gram-negative marine bacteria. Type 4 is a fungal infection occurring mostly in immunocompromised persons. (See Comparing types of necrotizing fasciitis by clicking the PDF icon above.)
Disease progression
The four types of NF progress in a similar way. Bacteria secrete pyrogenic exotoxin A, which stimulates cytokines. These cytokines damage the endothelial lining; fluid then leaks into the extravascular space.
M proteins in streptococci and β-hemolytic streptococci exacerbate the immune reaction by inhibiting phagocytosis of polymorphonuclear leukocytes and normal neutrophil chemotaxis. As the immune reaction increases, blood vessels dilate, allowing toxins to leak through vessel walls, which in turn decreases blood flow. As the cascade continues, hypoxic conditions cause facultative aerobic organisms to grow and become anaerobic. These bacteria exacerbate destruction of surrounding cells and lead to release of carbon dioxide, water, hydrogen, nitrogen, hydrogen sulfide, and methane. As the infection continues to progress, toxins spread throughout the bloodstream and the patient becomes septic.
Assessment
Obtain the patient’s medical history and description of the wound. Determine when the changes first appeared and whether the affected area seemed to get worse recently.
In all NF types, patients commonly present with a small, painful area (possibly with entry marks) but no other signs or symptoms. The wound may appear as a bulla, cellulitis, or dermatitis, representing an infection developing in underlying tissues. The skin may have a wooden-hard feel as the infection progresses to the subcutaneous space and causes necrosis. The wound becomes discolored and necrotic; drainage is rare until surgical debridement begins. The patient quickly develops fever, chills, nausea, and vomiting. As NF progresses, bullae become dark purple with darkened edges; the patient grows disoriented and lethargic, and organ failure and respiratory failure
ensue. Without treatment, the patient dies.
Diagnosis
Diagnostic tests usually include magnetic resonance imaging, complete blood count with differential, comprehensive metabolic panel, and cultures. (See Diagnostic findings in necrotizing fasciitis by clicking the PDF icon above.)
Treatment
Immediate surgical debridement and broad-spectrum antibiotics are needed to stop the immune response to infection. Clindamycin, gentamicin, penicillin, or metronidazole may be given alone or in combination until culture results are available. Supportive care includes total parenteral nutrition for nutritional support, I.V. fluids, and oxygen. Limb amputation should be done only as a last resort.
Surgical debridement involves penetrating deep into the fascia and removing all necrotic tissue. After the first debridement, release of “dishwater fluid” may occur.
Administering hyperbaric oxygen therapy (HBOT) after the first debridement increases tissue oxygenation, thus reducing tissue destruction by anaerobic bacteria. During HBOT (usually given as a 90-minute treatment), the patient breathes 100% oxygen in an environment of increasing atmospheric pressure.
HBOT should be given in conjunction with surgical debridement (usually after each debridement) and should continue until necrotic tissue ceases and cell destruction stops. HBOT also promotes collagen synthesis and neoangiogenesis (new blood vessel growth), which boosts blood supply and oxygen to tissues.
Adverse effects of HBOT include ear pain, oxygen toxicity, and seizures. Ear pain can be minimized by swallowing or yawning. If the patient continues to have ear pain, ear tubes may be inserted by an otolaryngologist. During HBOT, air breaks (intervals of breathing room air) are important in controlling oxygen toxicity (the main cause of seizures).
Throughout the HBOT treatment period, wound dressings must be simple. Well-moistened gauze dressings and an abdominal pad provide good support. Once necrotic destruction occurs, dressings depend on wound size and the need to fill cavities. The patient may require a diverting colostomy, depending on wound
location and the amount of uncontrolled diarrhea. Blood glucose levels must be monitored before and after HBOT, as this treatment affects blood glucose.
Supportive care and follow-up treatment
During initial treatment, patients need supportive care and monitoring. Once they’re out of danger, begin teaching them how to prevent NF recurrences. Advise them to control blood glucose levels, keeping the glycated hemoglobin (HbA1c) level to 7% or less. Caution patients to keep needles capped until use and not to reuse needles. Instruct them to clean the skin thoroughly before blood glucose testing or insulin injection, and to use alcohol pads to clean the area afterward.
Before discharge, help arrange the patient’s aftercare, including home health care for wound management and teaching, social services to promote adjustment to lifestyle changes and financial concerns, and physical therapy to help rebuild strength and promote the return to optimal physical health. One helpful patient resource is the National Necrotizing Fasciitis Foundation. The Centers for Disease Control and Prevention section on necrotizing fasciitis includes “Common sense and great wound care are the best ways to prevent a bacterial skin infection.”
The life-threatening nature of NF, scarring caused by the disease, and in some cases the need for limb amputation can alter the patient’s attitude and viewpoint, so be sure to take a holistic approach when dealing with the patient and family. Today, NF has a much better survival rate than 2 decades ago when Jim Henson died. In my practice, I’ve seen four NF cases. Thanks to early identification, good wound care, and HBOT, these patients suffered only minimal damage.
Selected references
Boyer A, Vargas F, Coste F, et al. Influence of surgical treatment timing on mortality from necrotizing soft tissue infections requiring intensive care management. Intensive Care Med. 2009;35(5):847-853. doi:10.1007/s00134-008-1373-4.
Cain S. Necrotizing fasciitis: recognition and care. Practice Nurs. 2010;21(6):297-302.
Centers for Disease Control and Prevention. Notes from the field: fatal fungal soft-tissue infections after a tornado—Joplin, Missouri, 2011. MMWR. 2011;60(29):992.
Chamber AC, Leaper DJ. Role of oxygen in wound healing: a review of evidence. J Wound Care. 2011; 20(4):160-164.
Christophoros K, Achilleas K, Vasilia D, et al. Postraumatic zygomycotic necrotizing abdominal wall fasciitis with intraabdominal invasion in a non immunosuppressed patient. Internet J Surg. 2007;11(1). doi:10.5580/17a8.
Ecker K-W, Baars A, Topfer J, Frank J. Necrotizing fasciitis of the perineum and the abdominal wall-surgical approach. Europ J Trauma Emerg Surg. 2008;
34(3):219-228. doi:10.1007/s00068-008-8072-2.
Hunter J, Quarterman C, Waseem M, Wills A. Diagnosis and management of necrotizing fasciitis. Br J Hosp Med. 2011;72(7):391-395.
Magel DC. The nurse’s role in managing necrotizing fasciitis. AORN J. 2008;88(6):977-982.
Phanzu MD, Bafende AE, Imposo BB, Meyers WM, Portaels F. Under treated necrotizing fasciitis masquerading as ulcerated edematous Mycobacterium ulcerans infection (Buruli ulcer). Am J Trop Med Hyg. 2012;82(3):478-481.
Ruth-Sahd LA, Gonzales M. Multiple dimensions of caring for a patient with acute necrotizing fasciitis. Dimens Crit Care Nurs. 2006;25(1):15-21.
Stevens DL, Bisno AL, Chambers HF, et al; Infectious Diseases Society of America. Practice guidelines for the diagnosis and management of skin and soft-tissue infections. Clin Infect Dis. 2005;41(10):1373-1406.
Su YC, Chen HW, Hong YC, Chen CT, et al. Laboratory risk indicator for necrotizing fasciitis score and the outcomes. ANZ J Surg. 2008;78(11):968-972.
Taviloglu K, Yanar H. Necrotizing fasciitis: strategies for diagnosis and management. World J Emerg Surg. 2007;2:19.
Lydia Meyers is a medical reviewer for National Government Services in Castleton, Indiana, and a clinical liaison at CTI Nutrition in Indianapolis. She has 11 years of wound care experience in nursing homes, wound clinics, and home health.
