Grand Rounds

Coping with necrotizing fasciitis

By Donald G. Gallup, MD, and Ramon V. Meguiar, MD

The challenge is to identify this potentially life-threatening infection in time—and to treat it aggressively. The condition can appear seemingly out of the blue after vaginal delivery, C/S, or any gynecologic surgery.

Necrotizing fasciitis (NF)—a fast-moving soft-tissue infection that involves extensive necrosis of subcutaneous tissue—is still fatal to one in five female patients with this rare infection—making it just as dire a surgical emergency in 2004 as when Meleney first described it in 1924.¹ While mortality rates for all necrotizing soft-tissue infections (including cellulitis, fasciitis, and myositis) range from 6% to 76%,^2,3 the prognosis is poorer when NF involves a woman's perineum or vulva.^3-6 Because NF often comes on suddenly—and severely enough to involve extensive soft-tissue necrosis that may rapidly lead to death—it demands rapid diagnosis and prompt medical and surgical intervention. Our goal is to provide pointers to help diagnose this painful but often subtle infection—which may develop from complications of childbirth, gynecologic surgery, or even from burns, bites, and abscesses—and to offer guidelines for its management.

Predisposing factors include diabetes

Which women will develop NF? In profiling patients at risk, every current retrospective study has noted conditions like diabetes mellitus, obesity, heart disease, hypertension, and chronic renal disease among possible comorbidities.^4,5,7-9 Other comorbidities linked with NF are alcoholism with malnutrition, chemotherapy and radiation therapy, and conditions resulting in relative immunoincompetence, such as steroid use or HIV, older age, IV drug abuse, and organ transplants. In our retrospective series, we reported three or more comorbid conditions in 47% of nonpuerperal patients.⁸ Suspect the presence of NF in women with vulvar infections or postoperative patients with these predisposing comorbidities. In sites farther from the abdominal wall, insect bites and IV drug abuse have also been implicated. Unfortunately, though, about 10% of cases of NF from all sites have no predisposing factors.

Signs and symptoms

The presence of severe agonizing pain has repeatedly been a presenting symptom ever since NF was first reported.¹ However, some patients may present with a "minor" labial infection such as a boil or small abscess and there may be various local effects of edema and discoloration in the perineal area. Suspect NF in a postoperative patient with an abdominal incision when bluish-brown skin discoloration coexists with comorbid conditions like diabetes. Tense edema associated with NF from other sites, including the extremities, is seen in up to 38% of patients, while approximately 14% have sensory or motor deficits.^10,11 However, only 4.4% of our reported patients had a sensory deficit—the so-called "needle-prick" test.⁸ This test is easily done by inserting a sterile needle into a discolored area to evaluate numbness or anesthesia. Rarely can you elicit crepitance. Patients who've had abdominal incisions may release copious amounts of serous "dishwater" discharge.

Most importantly, for patients having a high-risk profile and a lesion suspicious for NF, draw a "circle" around the affected area and re-evaluate them promptly—within 2 to 4 hours. Don't wait until the next day. If the area increases or changes in character, consider operative intervention. We've also noticed a characteristic triad of sepsis, inordinate pain, and unilateral edema in postpartum patients with perineal NF—a triad that should arouse suspicion.⁸

Diagnosing an elusive disorder

NF infections in women, whether in the abdominal wall or vulvar area, are usually polymicrobial.^7,12,13 In female patients, NF is usually caused by a synergistic polymicrobial infection, often seen in patients with comorbidities. Fulminant septicemia, which is probably associated with toxins, enzymes, or even antigens, has been linked with NF of the pelvis or abdomen. So have indolent infections, wherein NF develops in a compromised host.¹⁴ The two are most likely the same disease with different presentations. The organisms most commonly involved with rapid spread are clostridia species and group A beta-hemolytic streptococcus.^15,16

While blood cultures are seldom helpful in treating patients with suspected NF, they may be worthwhile for women with secondary Candida septicemia, which often occurs in patients with comorbid conditions. Gram's stains, on the other hand, may help. Fifty percent of our patients have a paucity of white blood cells in Gram's stains, which suggests some unknown pathophysiologic process.⁸ The relative lack of WBCs may be due to toxins, such as pyogenic exotoxins A and B, M proteins of Streptococcus pyogene, and various enzymes produced by the synergistic bacterial infection.

CT may be pivotal. Wall and colleagues noted gas on plain films in 32% and 39% of patients in their two series of cases.^10,11 CT or magnetic resonance imaging has helped to distinguish NF from cellulitis and may assist in early intervention.^17-19 Radiographic studies of any type may lack sufficient sensitivity to make a critical diagnosis. Even so, if the diagnosis is in doubt, emergent studies, preferably CT, may be pivotal in achieving appropriate early surgical intervention (Figure 1).

If the diagnosis is still unclear. Roberts advocated examination under anesthesia and excision if a high index of suspicion for vulvar and perineal NF exists.^4,20 If you find tissue necrosis, perform radical excision, as outlined later. Wound exploration is a valid approach if there's any doubt about NF versus cellulitis. When the diagnosis is unclear, another option is to perform a frozen section biopsy, which can be done at the bedside, and can often distinguish NF from other inflammatory conditions.²¹

Management demands aggressive surgical, medical treatment

NF is a surgical emergency for which an early, aggressive surgical procedure is the single most important approach. Debridement must consist of resection of all necrotic tissue until bleeding is encountered (Figures 2 and 3). Whether NF occurs in the abdominal wall or vulvar/perineal area, our practice (which is supported by others) is to start broad-spectrum antibiotics, including penicillin, as soon as we suspect NF (Table 1).²²

TABLE 1
Strategies for managing patients with necrotizing fasciitis

Obtain WBC count, serum electrolytes, serum calcium

If the diagnosis is in doubt, order radiographic studies

Obtain aerobic, anaerobic cultures plus Gram's stain of wound

Place central line and Foley catheter

Have plastic surgeon, gynecologic oncologist—or both—present at surgery to help evaluate resection for later flaps or grafts

Perform complete and radical dissection of all necrotic tissue at initial surgery

Be prepared to reexamine and excise tissue in the operating room

Consider diverting loop colostomy or ileostomy in patents with large perineal defects close to the anus

Consider TPN or enteral feedings

Consider hyperbaric oxygen postoperatively

TPN—total parental nutrition

For patients with large defects close to the anus, a temporary loop colostomy or ileostomy (which can often be done laparoscopically) may prevent contamination, particularly when flaps are necessary to cover defects. Because these patients are often nutritionally depleted, they may benefit from postoperative enteral alimentation or total parenteral nutrition. In our series, we used synthetic grafts for abdominal fascial defects or myocutaneous or rotational skin flaps in 39% of our patients.⁸ Flaps, which accelerate the healing process and restore a cosmetically appealing appearance, are constructed once healthy granulation tissue is present and can often be tailored from surrounding tissues, depending on the defect (Figure 4).²³ If your institution is equipped, seriously consider administering hyperbaric oxygen postoperatively, because it may play a supportive role, and has reduced morbidity and mortality rates in selected patients.^11,24

These aggressive surgical and medical approaches have reduced the mortality rate to 13% in recent series (Table 2).^8,25,26 (Delaying surgery for more than 48 hours resulted in the death of 66.7% of our patients with NF.⁸) The mortality in another series of women was 73.3% when surgery was delayed for more than 48 hours.⁷

TABLE 2
Comparative survival for patients with NF

Although relatively rare, NF of the perineum or abdominal wall in ob/gyn patients is a life-threatening surgical emergency. Many of these patients also have diabetes and hypertension and are older. In the postpartum patient, the triad of sepsis, inordinate pain, and unilateral perineal edema should raise your suspicion for NF. Adherence to the management guidelines listed in Table 1 can improve recovery rates and reduce mortality rates.

REFERENCES

1. Meleney FL. Hemolytic streptococcus gangrene. Arch Surg. 1924;9:317-364.

2. Sudarsky LA, Laschinger JC, Coppa GF, et al. Improved results from a standardized approach in treating patients with necrotizing fasciitis. Ann Surg. 1987;206:661-665.

3. Stone HH, Martin JD Jr. Synergistic necrotizing cellulitis. Ann Surg. 1972;175:702-711.

4. Roberts DB, Hester LL. Progressive synergistic bacterial gangrene arising from abscesses of the vulva and Bartholin's gland duct. Am J Obstet Gynecol. 1972;114:285-291.

5. Addison WA, Livengood CH 3rd, Hill GB, et al. Necrotizing fasciitis of vulvar origin in diabetic patients. Obstet Gynecol. 1984;63:473-479.

6. Fisher JR, Conway MJ, Takeshita RT, et al. Necrotizing fasciitis. Importance of roentgenographic studies for soft-tissue gas. JAMA. 1979;241:803-806.

7. Stephenson H, Dotters DJ, Katz V, et al. Necrotizing fasciitis of the vulva. Am J Obstet Gynecol. 1992;166:1324-1327.

8. Gallup DG, Freedman MA, Meguiar RV, et al. Necrotizing fasciitis in gynecologic and obstetric patients: a surgical emergency. Am J Obstet Gynecol. 2002;187:305-311.

9. Roberts DB. Necrotizing fasciitis of the vulva. Am J Obstet Gynecol. 1987;157:568-571.

10. Wall DB, Klein SR, Black S, et al. A simple model to help distinguish necrotizing fasciitis from nonnecrotizing soft tissue infection. J Am Coll Surg. 2000;191:227-231.

11. Wall DB, de Virgilio C, Black S, et al. Objective criteria may assist in distinguishing necrotizing fasciitis from nonnecrotizing soft tissue infection. Am J Surg. 2000; 179:17-21.

12. Goepfert AR, Gunn DA, Andrews WW, et al. Necrotizing fasciitis after cesarean delivery. Obstet Gynecol. 1997;89:409-412.

13. Schorge JO, Granter SR, Lerner LH, et al. Postpartum and vulvar necrotizing fasciitis. Early clinical diagnosis and histopathologic correlation. J Reprod Med. 1998;43: 586-590.

14. Meltzer RM. Necrotizing fasciitis and progressive bacterial synergistic gangrene of the vulva. Obstet Gynecol. 1983;61:757-760.

15. Soper DE. Clostridial myonecrosis arising from an episiotomy. Obstet Gynecol. 1986;68(3 suppl):26S-28S.

16. Golshani S, Simons AJ, Der R, et al. Necrotizing fasciitis following laparoscopic surgery. Case report and review of the literature. Surg Endosc. 1996;10:751-754.

17. Schmid MR, Kossmann T, Duewell S. Differentiation of necrotizing fasciitis and cellulitis using MR imaging. AJR Am J Roentgenol. 1998;170:615-620.

18. Meltzer DL, Kabongo M. Necrotizing fasciitis: a diagnostic challenge. Am Fam Physician. 1997;56:145-149.

19. Walshaw CF, Deans H. CT findings in necrotising fasciitis—a report of four cases. Clin Radiol. 1996; 51:429-432.

20. Roberts DB. Necrotizing fasciitis of the vulva. Am J Obstet Gynecol. 1987;157:568-571.

21. Majeski J, Majeski E. Necrotizing fasciitis: improved survival with early recognition by tissue biopsy and aggressive surgical treatment. South Med J. 1997; 90:1065-1068.

22. Majeski JA, John JF Jr. Necrotizing soft tissue infections: a guide to early diagnosis and initial therapy. South Med J. 2003;96:900-905.

23. El-Khatib HA. V-Y fasciocutaneous pudendal thigh flap for repair of perineum and genital region after necrotizing fasciitis: modification and new indication. Ann Plast Surg. 2002;48:370-375.

24. Riseman JA, Zamboni WA, Curtis A, et al. Hyperbaric oxygen therapy for necrotizing fasciitis reduces mortality and the need for debridements. Surgery. 1990;108:847-850.

25. McHenry CR, Azar T, Ramahi AJ, et al. Monomicrobial necrotizing fasciitis complicating pregnancy and puerperium. Obstet Gynecol. 1996;87:823-826.

26. Cabrera H, Skoczdopole L, Marini M, et al. Necrotizing gangrene of the genitalia and perineum. Int J Dermatol. 2002;41:847-851.

DR. GALLUP is Director of Gynecologic Oncology and Professor and Chair of the Department of Obstetrics and Gynecology at Mercer University School of Medicine, Savannah, Ga., and Director of Gynecologic Oncology at Memorial Health University Medical Center, Savannah, Ga. He was a speaker on incisions and closures at this year's annual ACOG meeting.

DR. MEGUIAR is Assistant Professor, Department of Obstetrics and Gynecology, Mercer University School of Medicine and Memorial University Medical Center, Savannah, Ga.

Take-home messages

• A characteristic triad of sepsis, inordinate pain, and unilateral edema should raise a red flag for perineal necrotizing fasciitis (NF).

• Because NF is a surgical emergency, early aggressive surgery is the single most important approach. It's also crucial to start broad-spectrum antibiotics, which include penicillin, as soon you suspect NF.

• For high-risk patients with a suspicious lesion for NF, draw a "circle" around the affected area and re-evaluate within 2 to 4 hours. If the area increases or changes in character, consider surgery.

• CT studies may be pivotal in achieving appropriate early surgical intervention.

• Suspect NF in a postoperative patient with an abdominal incision when bluish-brown skin discoloration coexists with comorbid conditions like diabetes.

 

Donald Gallup, Ramon Meguiar. Grand Rounds: Coping with necrotizing fasciitis. Contemporary Ob/Gyn Jun. 1, 2004;49:38-46.