Localized soft tissue injury resulting from unrelieved pressure. Normally over a bony prominence.
Pathophysiology:
- When compression of soft tissue exceeds the capillary pressure it leads to ischemia that if not relieved will progress to necrosis and ulceration even in well-vascularized areas
Factors that directly contribute to pressure sore formation:
- Decreased mobility
- Decreased sensation
- Friction
- Moisture
Factors the indirectly contribute to pressure sore formation:
- Poor nutrition
- Diabetes
- Age
Staging:
- Stage I – well circumscribed, nonblanching erythema
- Stage II – partial thickness skin loss
- Stage III – full thickness skin loss involving subcutaneous tissue down to muscle fascia
- Stage IV – through muscle, to bone, with undermining or sinus tracts
- Suspected Deep Tissue Injury: maroon color to intact skin with likely underlying deep tissue injury
- Unstageable: full thickness ulcer with eschar at the base
Treatment – directed by stage
- Stage I-II – nonsurgical
- protective barriers
- maintain moist wound environment
- III-IV
- Debridement
- Dressings to encourage healing
- Reconstructive surgery (last level on the treatment ladder)
Reconstruction:
- Given the high risk of recurrence of pressure sores following reconstruction, the is to optimize the patient prior to surgery and design a flap that has the possibility for future re-advancement
- Preoperative Optimization:
- Nutrition:
- Serum albumin > 2.0
- 1.5 to 3.0 g/kg/d of protein
- 25-35 cal/kg of non-protein calories
- Infection:
- Soft Tissue:
- Common among wounds – debridement of all non-viable tissue is necessary for wound healing
- Osteomyelitis:
- Diagnosis:
- *bone biopsy is gold standard. However, imaging can also be used. A gadolinium MRI is the best imaging study
- Treatment:
- Both abx and surgical
- Relief of Pressure:
- Need to come up with strategies preoperatively for relieving pressure over the site of the pressure sore (ex. Air fluid mattress and wheelchair fitting to relieve pressure points).
- Relieving pressure for 5 minutes every 2 hours will allow adequate perfusion and prevent breakdown
- Spasm/Contractures:
- These are both common in patients with spinal cord injuries and can contribute to the formation of pressure sores
- Treatment of spams: medical – baclofen, diazepam, dantrolene
- Treatment of contractures: start with physical therapy
- Management of AIC
- Discussion of fecal or urinary diversion if needed
Common Flaps Used for Pressure Sore Reconstruction by Site:
- Trochanteric – TFL
- Sacral – lumbosacral advancement
- Gluteal/ischial – VY advancements
- Posterior thigh flap
- Pedicle: inferior gluteal artery
- Design: fasciocutaneous – VY, or superiorly based tongue flap
- Note: severs all connections from semitendinosus/semimembranosus/biceps femoris to skin so cannot use any of those as musculocutaneous flaps
- If the patient is non-ambulatory, muscle can be used for reconstruction – this provides the best coverage with the most reliable blood supply without risk of functional imbalance
- Options: gracilis, gluteal muscle flap
Miscellaneous
- Treatment of Paraplegic Patients:
- Autonomic dysreflexia
- Signs: headache, hypertension, bradycardia, flushing, and sweating due to uncontrolled sympathetic response to a stimulus, usually in paraplegics above T6. Stimuli generally include: bladder distention, rectal distention, musculoskeletal injury, pregnancy/labo
- Anesthetic Considerations
- administration of succinylcholine in paraplegics may cause hyperkalemia (upregulated receptors in damaged muscles).
- Signs of hyperkalemia: early: peak T waves late: cardiac arrhythmias. Treatment: calcium carbonate, to stabilize cellular membranes, then bicarb and glucose/insulin to offset the acidosis and bring K back into cells