54. Principles of restricted mobility management
prevention of thromboembolism
CHAPTER CONTENTS
Thrombus formation 377
Role and responsibilities of the midwife 380
Summary 381
Self-assessment exercises 381
References 381
LEARNING OUTCOMES
Having read this chapter the reader should be able to:
• discuss the risk factors for VTE in childbearing women
• describe the leg and breathing exercises that can be undertaken during any periods of immobility
• discuss briefly when and how anticoagulation therapy may be prescribed
• discuss how graduated compression stockings are correctly applied and worn
• highlight the midwife’s role and responsibility in relation to the prevention of VTE.
This chapter focuses on the principles of preventing the formation of thromboembolism. Venous thromboembolism (VTE) remains a significant cause of maternal mortality (Lewis 2007). Restricted mobility is one of several risk factors that affect its incidence. Complications such as thromboembolism affect physical, psychological and social aspects of the woman’s care at a time when she should be preparing for/enjoying motherhood. As well as life threatening, the implications may also be both short and long term. The current risk factors are highlighted, prophylactic measures (exercises, deep breathing, anticoagulation and graduated compression stockings) are discussed and the role and responsibilities of the midwife are summarised.
Thrombus formation
There is a higher risk of blood clot formation (thrombus) if there is stasis in blood flow, greater coagulation of the blood and damage to vessel walls (Elliott & Pavord 2008). Child bearing, with changes in blood chemistry, pressure from the gravid uterus and relaxation of the vessel walls, has all three of these risks physiologically. It is suggested that pregnancy increases the risk of VTE 10-fold, the puerperium 25-fold (McColl et al 1997). The risks in pregnancy are immediate; 10 women died from pulmonary embolism (migration of the thrombus from leg or abdominal veins to the lungs) in their first trimester in the period 2003–2005 (Drife 2007).
Midwives need to be alert to additional risk factors that women may have:
• previous venous thromboembolism or family history
• increasing age, over 35 years
• existing or acquired haematological abnormalities, e.g. clotting disorders, sickle-cell disease, lupus anticoagulant
• obesity (particularly morbidly obese women), where body mass index is >30 at booking
• parity 4 or higher
• gross varicosities
• medical illness (particularly inflammatory disorders), paralysis of lower limbs
• pregnancy-related disorders: pre-eclampsia, hyperemesis, ante- or postpartum haemorrhage, prolonged labour
• surgery in pregnancy or puerperium
• delivery by midcavity forceps
• significant infection, e.g. pyelonephritis
• immobility more than 4 days, particularly after delivery
• ovarian hyperstimulation syndrome.
(Adapted from Drife 2007)
The greater the number of risks, the higher the possibility of thrombus formation. It should also be noted that as situations change, the need for risk assessment is ongoing.
Prophylaxis
For all childbearing women immobolisation should be kept to a minimum and dehydration avoided (RCOG 2004). This means that all women should be encouraged to remain active, but if for whatever reason there are longer periods of inactivity then specific exercises to aid venous blood flow should be undertaken. The midwife can utilise the skills of an obstetric physiotherapist, particularly for a woman in high dependency care or on long-term bed rest.
