Introduction

Most women of childbearing age are healthy; however, in a small proportion, severe and sometimes life-threatening complications occur during pregnancy. In unplanned admissions to the intensive care unit (ICU), critical illness in pregnancy is often due to direct complications of pregnancy rather than exacerbations of pre-existing conditions. This cohort of patients is unique in that their management requires consideration of the physiological changes associated with pregnancy as well as concern for the well-being of the foetus. The management of ICUs may facilitate timely recognition and management of acute illness. In this chapter, we review the role of ICUs, early warning scores and critical care outreach services in relation to maternal morbidity and mortality.

History of intensive care

Florence Nightingale first described the concept of an ‘ICU’ during the Crimean War, when she recognised that some soldiers required more frequent monitoring and more intense care. Focussing time and resources to an area of the ward or hospital designed to look after the sickest patients improved the care of the critically ill. However, it was only when large number of patients required organ support, in the form of manual ventilation during the polio epidemic of 1952, that modern intensive care was propagated. Care was most effective when centralised to one location in the hospital, leading to the organisation of respiratory ICUs.

History of intensive care

Florence Nightingale first described the concept of an ‘ICU’ during the Crimean War, when she recognised that some soldiers required more frequent monitoring and more intense care. Focussing time and resources to an area of the ward or hospital designed to look after the sickest patients improved the care of the critically ill. However, it was only when large number of patients required organ support, in the form of manual ventilation during the polio epidemic of 1952, that modern intensive care was propagated. Care was most effective when centralised to one location in the hospital, leading to the organisation of respiratory ICUs.

The ICU in modern practice

The fundamental concepts of intensive care remain unchanged – creation of designated areas to look after the sickest patients with high nurse-to-patient and physician-to-patient ratios. Continuous monitoring of vital signs and the institution of organ support are often required in the care of the critically ill patient. Patients with established acute organ dysfunction should clearly be considered for an ICU admission. Those who have undergone a major procedure and are at risk of deterioration should be closely monitored in the ICU for early identification of clinical deterioration and prompt treatment.

Members of the team

Critical care management of the obstetric patient requires a multidisciplinary approach. Members of this team include physicians specialised in maternal medicine, neonatologists, anaesthetists, intensivists, midwives, nurses and other allied health-care team members, including physiotherapists, pharmacists, nutritionists and bio-technicians. Neonatologists are an important resource for patients and families when making decisions regarding the intervention on behalf of mother and foetus and in helping define the complications arising from premature delivery and issues of viability. With one physician as a primary provider, the interdisciplinary team can work together and provide optimum care. A patient-centred approach incorporating all members of the team and families is desired to provide quality evidence-based care. Multidisciplinary teams with protocol-driven care to assist with the critical-care decision-making process have been shown to improve patient outcome . The unique area of expertise that each team member can provide allows for an effective and efficient use of resources .

There is heterogeneity in the staffing models, admission criteria and sub-specialisation of ICUs globally. The concept of open ICU is where the attending or consultant physician of the patient with appropriate privileges to treat may admit the patient to an ICU with minimal screening. Intensivists in this situation are available as consultants with the attending physician making the management and treatment plans. This maintains continuity of care; however, there may be delays in patient management due to inconsistent primary physician availability. A closed ICU model provides a specialist intensivist directing the care of the critically ill patient with adherence to well-defined admission and discharge criteria. Approximately, one-quarter of units in the US are closed units . There is increasing evidence that ICUs led by intensive care medicine specialists improve patient outcome . However, the hybridisation of the open and closed critical care unit designs usually provides the best care. Considerations must be made such as the location of critical care unit within the hospital together with practicalities such as appropriateness of population size. For many hospital settings, a separate obstetric ICU is not a practical use of resources.

Maternal high-dependency units

Table 1 summarises the four levels (0–3) commonly used to describe patient-care requirements within the hospital. Many women who are admitted to ICUs do not require mechanical ventilation and are only admitted for <24 h . There may be insufficient resources to admit all level 2 patients to ICU. Patients may still be pregnant while requiring intensive care therapy, and some aspects of the maternal and foetal management might be better cared for in the obstetric unit.

Many of these patients may be successfully managed on a specialist-maternity high-dependency unit (HDU) on the labour ward. The delivery suite also has the advantages of allowing mother and baby to remain together following delivery and increased staff familiarity with conditions such as pre-eclampsia and post-partum haemorrhage. However, midwives within the UK (and elsewhere) have limited nursing experience as well as management of the severe end of the spectrum of medical conditions. Sufficient training is necessary, if midwives are expected to look after women with invasive monitoring (e.g., arterial lines). If this can be provided, some of these patients can be looked after on HDUs located on the labour ward. In smaller hospitals, transfer to a medical or surgical ICU may be preferable .

Whether patients are managed within the delivery suite, the general critical care facility or jointly with a general critical care outreach team, a multidisciplinary approach is of paramount importance, for example, with regular multidisciplinary team ward rounds . While round-the-clock anaesthetic input working in conjunction with senior obstetricians is available on labour wards within the UK and US to facilitate the delivery of high-quality level 2 care, a close communication with intensive care and other medical specialties must still be maintained . Ultimately, the level of care is allocated according to the clinical need, not the location, which may be a designated room, a normal labour room or a recovery area.

All obstetric units should be able to initiate emergency treatment until the patient is transferred to an ICU . Specialist obstetric units that provide high-dependency care facilities have lower rates of maternal transfer to ICUs and improved continuity of care before and after labour . The benefits of obstetric HDUs are likely to be determined by the hospital size and available resources. The safety, efficacy and cost of a HDU on the labour ward need to be evaluated further.