10.2 Puerperal Wound Infection, Mastitis & Breast Abscess

Puerperal Wound Infections: Cesarean & Perineal

Cesarean Incisional Surgical Site Infection (SSI)

• Incidence: Occurs in 3% to 5% of cesarean births, typically presenting between postpartum days 4 and 7.
• Clinical Features: Focal erythema, induration, localized warmth, severe incisional pain, and purulent or serosanguinous drainage from the incision.
• Management:
  1. Open the surgical incision by removing staples or sutures over the affected area.
  2. Evacuate all hematomas, seromas, or purulent exudate.
  3. Palpate the Rectus Fascia: Thoroughly inspect and palpate the deep fascial layer to ensure fascial integrity. If the fascia is intact, the infection is superficial. If the fascia is disrupted (fascial dehiscence), immediate surgical reclosure in the operating room is mandatory to prevent evisceration.
  4. Irrigate the wound thoroughly with normal saline and pack loosely with sterile saline-moistened gauze (wet-to-dry dressings) or apply a negative pressure wound therapy (wound VAC) device.
  5. Initiate oral antibiotics active against S. aureus and streptococci (Cephalexin 500 mg PO QID).

Perineal Laceration & Episiotomy Breakdown

• Infection & Dehiscence: Characterized by localized perineal edema, purulent exudate along suture lines, foul odor, and gaping wound edges.
• Midwifery Management: Remove loose sutures, debride necrotic debris, clean the base, and promote healing. While minor superficial breakdowns heal well by secondary intention with sitz baths, extensive third- or fourth-degree perineal breakdowns can be surgically re-repaired early (after infection is cleared and the tissue bed is clean and healthy).
• Life-Threatening Emergency — Necrotizing Fasciitis:
  • A rare, rapidly progressive, fulminant polymicrobial infection dissecting along the deep fascial planes of the perineum and vulva (Fournier gangrene).
  • Warning Signs: Severe, excruciating pain out of proportion to physical exam findings, wooden hardness of subcutaneous tissues extending beyond visible margins, dusky purplish-blue skin discoloration, skin bullae or blister formation, subcutaneous crepitus (gas in tissues), cutaneous anesthesia (from destruction of dermal nerves), and rapid progression to septic shock.
  • Immediate Action: Emergent surgical consultation for radical operative debridement, broad-spectrum IV antibiotics (vancomycin + piperacillin-tazobactam + clindamycin to inhibit toxin production), and critical care resuscitation.

Postpartum Mastitis & Breast Abscess

Lactational mastitis is an infection of the parenchymal breast tissue, affecting up to 10% to 20% of breastfeeding individuals, most commonly occurring during the second to fourth weeks postpartum.

Pathophysiology & Etiology

• The Two Core Drivers: (1) Milk Stasis (infrequent feedings, missed feeds, ineffective latch, or plugged lactiferous ducts) leads to overdistension of alveoli and retrograde milk extravasation into surrounding perilobular connective tissue, creating an ideal bacterial culture medium; (2) Bacterial Inoculation occurs through damaged, cracked, or excoriated nipple skin from infant oral flora or maternal skin colonization.
• Causative Organisms: Staphylococcus aureus is the causative agent in >70% to 80% of acute mastitis cases, with an increasing prevalence of Community-Acquired Methicillin-Resistant Staphylococcus aureus (CA-MRSA). Other organisms include Staphylococcus epidermidis, Streptococcus pneumoniae, Escherichia coli, and Enterococcus species.

Clinical Presentation

• Unilateral Distribution: Mastitis is almost exclusively unilateral (bilateral mastitis is rare and raises suspicion for streptococcal infection).
• Physical Signs: Sudden appearance of a hard, exquisitely tender, hot, swollen, wedge-shaped area of intense erythema radiating from the areola toward the periphery of one breast.
• Systemic Symptoms: High fever (typically ≥38.5°C / 101.3°F), accompanied by severe rigors, exhaustion, generalized myalgias, headache, and a feeling of acute systemic toxicity ("flu-like illness").

Clinical Differentiation: Breast Engorgement vs. Plugged Duct vs. Mastitis vs. Abscess
├── Engorgement  ──> Bilateral, generalized hard/warm/swollen breasts, low fever (<38°C), postpartum days 2-4
├── Plugged Duct ──> Unilateral, localized palpable tender lump, NO systemic symptoms, normal temperature
├── Mastitis     ──> Unilateral, focal wedge-shaped erythema, intense pain, FEVER ≥38.5°C, systemic flu-like chills
└── Abscess      ──> Unilateral, fluctuant tender mass, persistent fever after 48h antibiotics, ultrasound fluid pocket

Midwifery Management of Lactational Mastitis

1. Continued, Frequent & Complete Milk Drainage (Essential Rule):
   • The single most vital management principle is frequent, complete emptying of the affected breast.
   • The mother must be strongly encouraged to continue breastfeeding or pumping every 1.5 to 2.5 hours.
   • Infant Safety: Nursing from the infected breast is entirely safe for the healthy, term infant. Breast milk contains maternal antibacterial enzymes, lactoferrin, and secretory IgA; the infant's nasopharynx is already colonized with maternal skin organisms.
   • Caution: Abrupt cessation of breastfeeding (weaning) during active mastitis is strictly contraindicated! Sudden weaning dramatically worsens milk stasis, accelerating bacterial multiplication and markedly increasing the risk of progression to a fluctuant breast abscess.
2. Supportive Comfort Measures:
   • Apply warm, moist compresses to the breast immediately prior to nursing or pumping to facilitate the let-down reflex.
   • Apply cold compresses or chilled cabbage leaves between feedings to alleviate localized tissue edema and pain.
   • Ensure maternal bedrest, vigorous fluid hydration, and supportive, non-constrictive bras.
   • First-line analgesia: Ibuprofen (600–800 mg PO q6–8h) provides superior pain relief and reduces localized parenchymal inflammation.
3. Antimicrobial Pharmacotherapy:
   • If symptoms are mild and present for <12–24 hours, conservative breast emptying may be trialed. However, with documented fever ≥38.5°C or systemic symptoms, oral antibiotics must be initiated immediately for a full 10- to 14-day course:
   • First-Line Regimens:
     • Dicloxacillin 500 mg PO four times daily (QID) OR
     • Cephalexin (Keflex) 500 mg PO four times daily (QID).
   • In Severe Penicillin Allergy or Suspected CA-MRSA:
     • Clindamycin 300 mg PO four times daily (QID) OR
     • Trimethoprim-Sulfamethoxazole (TMP-SMX, Bactrim DS) 1 to 2 tablets PO twice daily (BID).
     • Lactation Caution with TMP-SMX: Avoid TMP-SMX in mothers nursing neonates under 1 month of age, jaundiced infants, or infants with known or suspected glucose-6-phosphate dehydrogenase (G6PD) deficiency due to the theoretical risk of kernicterus (sulfonamides displace bilirubin from albumin binding sites).

Breast Abscess

• Pathophysiology: Develops in 3% to 11% of mastitis cases, resulting from delayed antibiotic therapy, inadequate milk evacuation, or virulent MRSA infection. Bacterial necrosis produces a walled-off collection of purulent fluid within breast parenchyma.
• Clinical Signs: A well-demarcated, exquisitely tender, fluctuant, palpable mass, frequently accompanied by persistent high fever and systemic malaise despite 48 to 72 hours of appropriate oral antibiotics.
• Diagnostic Evaluation: Immediate high-resolution breast ultrasonography confirms the fluid collection and differentiates an abscess from inflammatory phlegmon or galactocele.
• Treatment:
  • Ultrasound-Guided Needle Aspiration: The preferred first-line, minimally invasive approach. A 16- to 18-gauge needle evacuates the cavity, repeated every 2 to 3 days if fluid reaccumulates. Minimizes tissue scarring and allows continued lactation.
  • Surgical Incision & Drainage (I&D): Reserved for multilocular abscesses, very large collections (>5 cm), or aspiration failures. Packed with sterile gauze or drained via a silicone catheter.
  • Continue antistaphylococcal antibiotics.
  • Feeding Instructions: The mother should continue breastfeeding from the unaffected breast. On the affected side, she should pump and discard milk if the drainage catheter or incision is within the areolar boundary, but may resume direct nursing as soon as the infant's mouth does not contact the wound.