Presentation on theme: "Pitfalls in Diagnosing Necrotizing Fasciitis"— Presentation transcript:
1 Pitfalls in Diagnosing Necrotizing Fasciitis SpotlightPitfalls in Diagnosing Necrotizing Fasciitis
2 Source and CreditsThis presentation is based on the July/August 2014 AHRQ WebM&M Spotlight CaseSee the full article atCME credit is availableCommentary by: Terence Goh, MBBS, Department of Plastic Surgery, Singapore General Hospital and Lee Gan Goh, MBBS, Division of Medicine, National University Health System, SingaporeEditor, AHRQ WebM&M: Robert Wachter, MDSpotlight Editor: Bradley A. Sharpe, MDManaging Editor: Erin Hartman, MS
3 ObjectivesAt the conclusion of this educational activity, participants should be able to:State the epidemiology of necrotizing fasciitisAppreciate the high mortality associated with necrotizing fasciitisExplain the pathophysiology of necrotizing fasciitisDescribe the main challenges in the diagnosis of necrotizing fasciitisList steps which can be taken to avoid errors in the diagnosis of necrotizing fasciitis
4 Case: Diagnosing Necrotizing Fasciitis A 49-year-old previously healthy man presented to the emergency department (ED) after falling at work 3 days before. He had presented to a different ED one day prior with diffuse pain on his left side (the side of impact) and was given non-steroidal anti-inflammatory medications and sent home. He presented to this new ED with persistent and worsening left arm, chest, abdomen, and thigh pain. On physical examination, he was afebrile but tachycardic. He had diffuse, tender ecchymoses involving his left shoulder, upper chest, lateral abdomen, and thigh. Although ED physicians felt he had simple bruising from the fall, they noted that he was in severe pain requiring intravenous opiates and that he was unable to independently ambulate.
5 Case: Diagnosing Necrotizing Fasciitis (2) Because of these symptoms, blood tests were obtained and results showed a white blood cell count of 2.8 x 109/L (normal range: 3.5–10.5 x 109/L) and acute renal insufficiency with a creatinine of 1.4 mg/dL (normal range: 0.6–1.2 mg/dL). A CT scan of the abdomen and pelvis showed ʺinduration in the left quadriceps muscle and fluid layering in the abdominal wall.ʺ He was seen by the trauma surgical service, who felt the findings were due to diffuse bruising. The patient was admitted to an internal medicine service. Due to ED crowding, he remained in the ED overnight, receiving only intravenous fluids and intravenous opiates for his pain.
6 Case: Diagnosing Necrotizing Fasciitis (3) Overnight, his pain worsened and he had persistent tachycardia. Early morning lab results showed a white blood cell count of 1.6 x 109/L, a creatinine of 1.6 mg/dL, a creatine kinase of 2650 U/L (normal range U/L) (evidence of muscle breakdown), and a lactate of 6.2 mg/dL (normal range 0.5−2.2 mmol/L) (evidence of tissue hypoxia). He was seen by the internal medicine team mid-morning and diagnosed with rhabdomyolysis from trauma and acute renal failure. He continued to receive intravenous fluids. His pain had become so severe that he was switched to dilaudid, administered through a patient-controlled analgesia (PCA) pump.
7 Case: Diagnosing Necrotizing Fasciitis (4) Later that day, the patient had progressive respiratory distress and developed septic shock. He was re-evaluated by the surgical service and felt to have probable necrotizing fasciitis with pyomyositis. He was urgently taken to the operating room, where he required debridement of 7300 cm/sq (an area roughly 2 feet by 4 feet) of skin and soft tissue from his left arm and axilla, anterior chest wall, abdominal wall, thigh, and leg. After surgery, he was progressively hypotensive despite multiple vasopressors. He developed multi-organ dysfunction and ultimately, after discussions with his family, care was withdrawn and he died peacefully. He underwent autopsy, which showed necrotizing fasciitis with pyomyositis secondary to methicillin-resistant Staphylococcus aureus (MRSA).
8 Skin and Soft Tissue Infections Skin and soft tissue infections (SSTIs) are incredibly common in both pediatric and adult medicineSSTIs involve suppurative bacterial or fungal invasion of the epidermis, dermis, or subcutaneous tissuesSSTIs can range in severity from benign to very serious (as in this case)
9 BackgroundAn expert panel has classified skin infections into 4 classes to help guide treatment:Afebrile and healthy, other than cellulitisFebrile and ill appearing, no unstable comorbiditiesToxic appearance, or at least one unstable comorbidity, or a limb-threatening infectionSepsis syndrome or life-threatening infection (e.g., necrotizing fasciitis)Eron LJ, Lipsky BA, Low DE, et al. Managing skin and soft tissue infections: expert panel recommendations on key decision points. J Antimicrob Chemother. 2003;52(suppl 1):i3-i17.
10 Background (2)This unfortunate case provides an opportunity to focus on necrotizing fasciitis (NF)NF is the most severe SSTI and the diagnosis is often missed or delayedDelay in diagnosis can have devastating consequences, as with this patientRouse TM, Malangoni MA, Schulte WJ. Necrotizing fasciitis: a preventable disaster. Surgery. 1982;92:765–770.
11 History and FeaturesHippocrates first alluded to a clinical condition of ʺnecrotizing erysipilasʺ in the 5th century BC as a complication of erysipelasSince then, numerous terms have been applied to this condition—phagedena gangrenosum, hospital gangrene, Meleney gangrene, and Fournier gangreneDominant feature is inflammation and necrosis of subcutaneous fat and deep fascia, with sparing of muscle, leading to severe systemic toxicityDescamps V, Aitken J, Lee MG. Hippocrates on necrotising fasciitis. Lancet. 1994;344(8921):556.Jackson R, Bell M. Phagedena: gangrenous and necrotic ulcerations of skin and subcutaneous tissue. Can Med Assoc J. 1982;126:Quirk WF Jr, Sternbach G. Joseph Jones: infection with flesh eating bacteria. J Emerg Med. 1996;14:Brewer GE, Meleney FL. Progressive gangrenous infection of the skin and subcutaneous tissues, following operation for acute perforative appendicitis: a study in symbiosis. Ann Surg. 1926;84:Fournier JA. Gangrène foudroyante de la verge. La Semaine Medicale. 1883;3:Wilson B. Necrotizing fasciitis. Am Surg 1952;18:
12 Epidemiology Necrotizing fasciitis is a rare disease The incidence of NF progressively increases among patients aged 50 years and olderNecrotizing fasciitis generally affects patients with chronic illnessesMore than half of patients have pre-existing medical conditions and 35% have at least twoDespite improved recognition, NF continues to be associated with a high mortality—in the past decade, reported to be between 15% to 45%Luca-Harari B, Ekelund K, van der Linden M, Staum-Kaltoft M, Hammerum AM, Jasir A. Clinical and epidemiological aspects of invasive Streptococcus pyogenes infections in Denmark during 2003 and J Clin Microbiol. 2008;46:O’Loughlin RE, Roberson A, Cieslak PR, et al; Active Bacterial Core Surveillance Team. The epidemiology of invasive group A streptococcal infection and potential vaccine implications: United States, 2000–2004. Clin Infect Dis. 2007;45:Goh T, Goh LG, Ang CH, Wong CH. Early diagnosis of necrotizing fasciitis. Br J Surg. 2014;101:e119-e125.
13 Microbial invasion of the subcutaneous tissues occurs either through: Pathophysiology of NFMicrobial invasion of the subcutaneous tissues occurs either through:External traumaDirect spread from a perforated viscusFrom a hematogenous sourceNF can affect any part of the body; extremities and the perineum are most commonly affectedSalcido RS. Necrotizing fasciitis: reviewing the causes and treatment strategies. Adv Skin Wound Care 2007;20:288–293.
14 Pathophysiology of NF (2) As infection progresses, the skin becomes more tense and red with indistinct marginsLocal pain is replaced by numbness (from compression or infarction of nerves)Next, skin becomes pale, then mottled and purple looking, and finally gangrenousIf gas-forming bacteria are present, air under the skin (crepitus) may be palpatedJones J. Investigation upon the nature, causes, and treatment of hospital gangrene, as it prevailed in the confederate armies Cambridge: Riverside Press. In: Hamilton FH, ed. Surgical Memoirs of the War of the Rebellion. New York, NY: Hurd & Houghton for the United States Sanitary Commission; 1871.
15 Evolution of Physical Signs in NF A clinical staging of the disease has been proposed based on cutaneous signs (see below)Symptoms may occur over hours to days and patients may present with sepsis or septic shockStage 1 (early)Stage 2 (intermediate)Stage 3 (late)Warm to palpationBlister or bullae formation (serous fluid)Hemorrhagic bullaeErythemaSkin fluctuanceSkin anesthesiaTenderness to palpitation (extending beyond apparent areas of skin involvement)Skin indurationCrepitusSwellingSkin necrosis with dusky discoloration progressing to frank gangreneWang YS, Wong CH, Tay YK. Staging of necrotizing fasciitis based on the evolving cutaneous features. Int J Dermatol. 2007;46:
16 Microbiology of NFHistorically, group A–beta-hemolytic streptococcus has been identified as the major cause of this infectionMore recently, researchers report NF is usually polymicrobial (Type I NF) rather than monomicrobial (Type II NF)Patient in case had NF secondary to methicillin-resistant Staphylococcus aureus (MRSA)Though not particularly common, community-acquired MRSA causing NF is an emerging clinical entityAndreasen TJ, Green SD, Childers BJ. Massive infectious soft-tissue injury: diagnosis and management of necrotizing fasciitis and purpura fulminans. Plast Reconstr Surg. 2001;107:Rouse TM, Malangoni MA, Schulte WJ. Necrotizing fasciitis: a preventable disaster. Surgery. 1982;92:765–770.McHenry CR, Piotrowski JJ, Petrinic D, Malangoni MA. Determinants of mortality for necrotizing soft-tissue infections. Ann Surg. 1995;221: 558–565.
17 Early Diagnosis of NFEarly diagnosis and adequate debridement within 24 hours are the most important factors impacting survivalPatients who receive surgery in the first 24 hours have mortality rate of 4.2%−6.7%Delaying surgery more than 24 hours is associated with mortality rates of 23%−75%Thus the relative risk of death is increased by more than 9 timesAndreasen TJ, Green SD, Childers BJ. Massive infectious soft tissue injury: diagnosis and management of necrotizing fasciitis and purpura fulminans. Plast Reconstr Surg. 2001;107:Wong CH, Chang HC, Pasupathy S, Khin LW, Tan JL, Low CO. Necrotizing fasciitis: clinical presentation, microbiology, and determinants of mortality. J Bone Joint Surg Am. 2003;85-A:
18 Challenges in Diagnosis Early diagnosis of necrotizing fasciitis (NF) is notoriously difficult and misdiagnosis is commonIn one study, NF was initially misdiagnosed 71.4% of the timeGoh T, Goh LG, Ang CH, Wong CH. Early diagnosis of necrotizing fasciitis. Br J Surg. 2014;101:e119-e125.
19 Challenges in Diagnosis (2) Multiple factors contribute to missed or delayed diagnosis:NF is a rare disease and many practitioners may be encountering it for the first timeNF initially can present similarly to other common soft tissue infections (as in this patient where it appeared he had simple bruising after his fall)The cutaneous signs of NF usually lag behind disease pathologySystemic signs of NF may not correlate with the cutaneous signs and vice versa; patients with extensive infection may not be systemically ill
20 Challenges in Diagnosis (3) The ʺhard signsʺ (e.g., bullae, numbness, crepitus, and skin necrosis) may be absentIn one study, they were present in only 43% of patients with NFFever may not be presentIn one review, only 32%−56% of patients with NF had a feverIn addition, initial symptoms of NF can be mild until the patient rapidly deteriorates and develops septic shockHong YC, Chou MH, Liu EH, et al. The effect of prolonged ED stay on outcome in patients with necrotizing fasciitis. Am J Emerg Med. 2009;27:Chan T, Yaghoubian A, Rosing D, Kaji A, de Virgilio C. Low sensitivity of physical examination findings in necrotizing soft tissue infection is improved with laboratory values: a prospective study. Am J Surg. 2008;196:
21 Strategies to Improve Diagnosis Multiple specific strategies may help prevent missing a diagnosis of NFRecognize pain out of proportion to the skin manifestations is a consistent feature of NFIn this case, the patient's severe pain requiring increasing intravenous opiates and a PCA pump should have been a sign that this was a more serious infectionRecognize NF often has rapid progression of infection with migration of the margins of erythema and skin induration despite use of antibioticsThis extension can progress over the course of hoursGreen RJ, Dafoe DC, Raffin TA. Necrotizing fasciitis. Chest. 1996;110:Patiño JF, Castro D. Necrotizing lesions of the soft tissue: a review. World J Surg. 1991;15:
22 Strategies to Improve Diagnosis (2) Three other cutaneous features can serve as diagnostic clues:Margins may be indistinct and poorly definedTenderness may extend beyond the apparent involved area of skinLymphangitis (inflammation of lymphatics, seen as streaking along skin) is rarely seen in NFUse of clinical pathways may also help aid in diagnosesInstitutions should involve multidisciplinary teams (often including surgeons, infectious disease specialists, and wound care experts)Education of frontline clinicians is also crucialMajeski J, Majeski E. Necrotizing fasciitis: improved survival with early recognition by tissue biopsy and aggressive surgical treatment. South Med J. 1997;90:Schuster L, Nuñez DE. Using clinical pathways to aid in the diagnosis of necrotizing soft tissue infections synthesis of evidence. Worldviews Evid Based Nurs. 2012;9:
23 Patient in this scenario presented with a history of trauma This CasePatient in this scenario presented with a history of traumaBased on initial clinical exam and diagnostic tests, it appeared to be a simple bruiseOver time, the patient exhibited a cardinal sign of NF—pain out of proportion to working diagnosisThe need for escalating intravenous opiates should have raised concerns for NF and prompted further diagnostic testing
24 Take-Home PointsEarly diagnosis of necrotizing fasciitis and early debridement is crucial to survival and reduction in morbidity and need for amputationEarly presenting signs of necrotizing fasciitis can be non-specificPain out of proportion to what one would expect for simple cellulitis should ring alarm bells and prompt physicians to expand the differential diagnosis to include NFThere is an evolution of clinical signs of necrotizing fasciitis—from early to late stagesA keen sense of suspicion and constant review of a patient are the only ways to reliably detect necrotizing fasciitis at an early stage