Pressure Ulcers

Pressure Ulcers

Pressure ulcers are a serious health problem. Although prevalence statistics may vary, what’s become starkly evident are the cost associated with pressure ulcers – cost in terms of suffering and diminished quality of life for patients. The cost to the health care industry in terms of resources consumed and manpower hours dedicated to managing to problem, and the very real monetary cost to individuals, health ensures and the government.

The cost implication is not the only consideration when a patient develops a pressure ulcer, these chronic wounds has a psychological effect on the patient and as could lead to health complications and even death.

Superman’s kryptonite was in fact septicemia due to a pressure ulcer.

Introduction

This article aims to define pressure ulcers, their Aetiology, treatment and most importantly prevention strategies.

Definition

A localised area of tissue necrosis that tends to develop when soft tissue is compressed between a bony prominence and an external surface for a prolonged period of time Bryant et al (1992)

Pressure ulcers are clinical manifestations of localized tissue death due to lack of blood flow in areas under pressure.

Aetiology

Pressure ulcers are caused by a combination of Extrinsic or External and Intrinsic or Internal factors

EXTERNAL FACTORS

–PRESSURE

–SHEAR

–FRICTION

–MOISTURE

INTRINSIC FACTORS

–AGE

–IMMOBILITY

–SENSORY DEFECTS

–BODY WEIGHT

–NUTRITION

–MEDICATION

–INCONTINENCE

–SMOKING

–INFECTION

–UNDERLYING DISEASE

–SKIN CONDITION

–OTHER

Pressure causing prolonged hypoperfusion can result in a cascade of hypoxia, acidosis, haemorrhage into the interstisium (non-blanchable erythema) and accumulation of toxic cellular waste leading to cell death and tissue necrosis.

Thus, if the pressure continues long enough tissues die. Muscle and fat are less tolerant of interruptions in blood flow than skin. Consequently, by the time sings of impeding necrosis appear on the skin, underlying tissue has probably suffered substantial damage. This contributes to the “Ice-berg effect” that describes the cone shaped tissue damage due to the pressure gradient.

Pressure over a bony prominence is transmitted in a cone-shape from the skin to the underlying bone. When an external force produces pressure against the skin, the bony prominence produces a counter-pressure

Shear force, or a force created when the skin of a patient stays in one place as the deep fascia and skeletal muscle slide down with gravity. This can also cause the pinching off of blood vessels which may lead to ischemia and tissue necrosis

Friction or a force resisting the shearing of skin. This may cause excess shedding through layers of epidermis.

Friction is the force between two surfaces rubbing together

Friction is the force that opposes the relative motion or tendency toward such motion of two surfaces in contact. It is not a fundamental force, as it is made up of electromagnetic forces between atoms. When contacting surfaces move relative to each other, the friction between the two objects converts kinetic energy into thermal energy, or heat.

Prolonged exposure to moisture can waterlog or macerate the skin. Maceration softens the connective tissue; the epidermis erodes more easily, degenerates and eventually sloughs off.

INTRINSIC FACTORS

Herewith just a brief overview of the most important factors

AGE

With advancing age come significant skin changes. A reduction in epidermal regeneration leads to skin thinning and ultimately will influence the skin’s protective function. Evagination of the papillary layer causes instability in the skin and lead to haemorrhage between the skin layers and risk of injury.

Aging results in a reduction of connective tissue resulting in a reduction of tensile strength, thus increasing the risk of damage.

A delayed immune response and reduction in blood supply to the dermis results in impaired healing.

Thus, elderly skin is more prone to damage due to pressure, friction or shear.

IMMOBILITY and SENSORY DEFECTS

This leads to an inability to relieve pressure or to react to pressure impulses.

MEDICATION

Taking into consideration medication that will have a negative effect on wound healing or influence the auto regulation capability of the capillaries.

UNDERLYING DISEASES

Especially diabetes and other diseases like Alzheimer’s

SMOKING

Smoking leads to vasoconstriction and reduced tissue perfusion.

CO2 binds to hemoglobin forming carboxyhemoglobin – Oxygen dissociation curve shifts to left exacerbating poor tissue oxygenation.

Nicotine also affects macrophage activity

Loss in appetite can lead to a Vitamin deficiency

INFECTION

A systemic infection leads to an increased metabolism and tissue breakdown

A systemic infection causes the wound to stay in the inflammatory stage

Research found that infection may reduce the pressure needed to cause tissue necrosis, thus influencing autoregulation of the capillaries, or there ability to resist pressure.

STAGING OF PRESSURE ULCERS

PREVENTION STATEGIES

Risk Assessment

It is absolutely vital that risk assessment is done on the patient to identify the presence of extrinsic and intrinsic factors that are known to increase the patient’s risk for pressure ulcer development. Risk assessment plays a vital role in prevention.

Various tools are available i.e. Braden or Norton risk assessment tools.

Specific prevention strategies

Managing pressure consists of the following aspects:

Positioning to address mobility deficit

Support aid and cushions

Beds and Mattresses

Managing skin integrity

Inspection

Cleaning

Moisturizing

Managing nutrition

Dietaryintake - focussing on protein intake, macro and micro nutrients and fluid maintenance.

SITES PRONE TO PRESSURE ULCERATION

Make use of cushions and pressure relieving devises to position you patient.

Semi-fowler’s position at 30° reduces friction

Rotating the patient at a 30° angle reduces pressure over the sacrum.