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Pressure Sores

Table of Contents

Introduction

Tissue ischemia due to prolonged compression, usually against a bony prominence, leading to wounds

Background

Etiology & Pathophysiology

  • Compression of soft tissue, usually against a bony prominence, exceeding capillary pressure leads to decreased perfusion → tissue ischemia → tissue necrosis → ulceration → wound
    • Capillary blood pressure = 12 – 32 mmHg
    • Degree of pressure is inversely proportional to time to ulceration 
      • Greater pressure →  less time required to injure tissue
    • Muscle is more susceptible to ischemia injury than skin
      • Cone shaped volume of injury
Pressure vs. time to ulceration curve
Cone shaped ischemia injury

Staging

  • Based on the National Pressure Sore Advisory Panel (last updated 2007)
 Stage IStage IIStage IIIStage IV
 
Depth of Soft Tissue Loss
  • None
  • Skin intact
  • Partial thickness skin
  • Full-thickness skin
  • Subcutaneous fat
  • Down to, but not through, fascia
  • Full-thickness skin loss
  • Subcutaneous fat
  • Muscle
  • Bone
  • Tendon
  • Ligament
  • Joint capsule
Clinical Features
  • Non-blanchable erythema
  • Blister, abrasion or shallow ulcer
  • +/- undermining, tunneling
  • +/- undermining, tunneling

Presentation

History

Physical Exam

  • Most common sites affected
    1. Ischial tuberosity (28%)
    2. Trocanter (19%)
    3. Sacrum (17%)
    4. Heel (9%)
    5. Scalp
  • Other sites that can be affected
    • Nose
      • Typically due to nasal cannula or nasotracheal tube
    • Ears 
      • Typically due to nasal cannula tubing or turned head
    • Scapula 
  • When supine, maximal pressure over heels, buttocks, sacrum
  • When sitting, maximal pressure over ischial tuberosities

Evaluation

Laboratory

  • Complete blood count (CBC)
  • Electrolyte panel
  • Hemoglobin A1C
  • Albumin
    • Half-life = 
  • Transferrin
    • Half-life =
  • Pre-albumin
    • Half-life =
    • Inverse relationship with C-reactive protein (CRP)

Imaging

  • Plain Xray
  • Bone scan
  • MRI

Microbiology

  • Presence of osteomyelitis
    • Bone biopsy = gold standard for diagnosis

Treatment

Goals

  • Eradication of infection
  • Closure of wound

Non-Surgical

Surgical

References