The importance of critical care provision in pregnancy is increasingly being recognised. In 2013, a study by the Intensive Care National Audit and Research Centre (ICNARC) and the Obstetric Anaesthetists’ Association (OAA) examined a large dataset of obstetric admissions to the intensive care unit (ICU). Women were more likely to be admitted to ICU in the postpartum period than while pregnant, and haemorrhage was the commonest cause in this group, followed by hypertensive disorders. Antenatal admissions were more heterogeneous but pneumonia, respiratory failure and sepsis predominated.
Most series give an overall ICU admission rate of 0.2-9 per 1000 deliveries, although there is much variation between countries and even units as a result of differences in patient population and selection. Most patients stay in the ICU for less than 3-4 days. Mortality rates are difficult to estimate for the above reasons but are generally low overall (in the order of 3-4% in reported UK series), although they range from 0% to 20% in published series worldwide. Objective prediction of mortality is hampered by the relative inability of standard scoring systems (e.g. APACHE) to allow for the physiological changes of pregnancy or the particular spectrum of conditions seen in pregnancy (e.g. platelet count has greater importance in obstetric patients than in the non-pregnant population).
However, such data only provide information on women who were admitted to ICU, and not those who were managed on the ward. The Confidential Enquiries into Maternal Deaths (CEMD) focus on deaths and therefore do not give a complete picture of critical illness and pregnancy, although recent reports have included sections about ICU management and selected causes of morbidity, in order to extract lessons to be learned. The need for adequate provision of ICU or high-dependency beds, especially in smaller delivery units, is repeatedly stressed. Some units have the facilities to provide high-dependency care on the labour ward; if not, clinicians will have a lower threshold for transfer to a general ICU. More recently, emphasis has been on providing ‘intensive care’ to the sick mother within the maternity unit - i.e. before she is actually admitted to the ICU; critical care outreach teams can provide valuable support.
Problems and special considerations
A modification of the Department of Health’s 2000 classification of critical care has been suggested for obstetrics (Table 155.1).
General ICU care is as for non-obstetric patients. Particular points to note include:
• The risks to the fetus and the need for fetal monitoring (if antepartum)
Table 155.1 Classification of criticalcare, modified for obstetrics
|
Level 0 |
Normal ward care of low-risk mother |
|
Level 1 |
Additional monitoring or intervention, or step down from higher level of care (e.g. risk of haemorrhage, neuraxial analgesia, oxytocin infusion, mild pre-eclampsia, medical condition such as congenital heart disease or diabetes) |
|
Level 2 |
Single organ support • Respiratory (e.g. requiring continuous oxygen, continuous positive airway pressure, bi-level positive airway pressure) • Cardiovascular (e.g. pre-eclampsia requiring intravenous antihypertensives, arterial or central venous lines, cardiac output monitoring, intravenous antiarrhythmic/antihypertensive/vasoactive drugs) • Neurological (e.g. magnesium to control seizures, intracranial pressure monitoring) • Hepatic (e.g. acute fulminant hepatic failure with consideration of transplantation) |
|
Level 3 |
Advanced respiratory support or two other organ systems support |
• The requirements of the patient’s partner and family
• The midwifery care required in the puerperium (if postpartum)
• The need for attention to drug safety if breastfeeding
• The physiological changes of pregnancy, including especially:
- Increased risk of aspiration and higher incidence of a difficult airway
- Increased oxygen demands and changes in respiratory function
- Apparently increased propensity of critically ill obstetric patients to develop acute lung injury
- Susceptibility to aortocaval compression
- Increased cardiac output and other cardiovascular changes
- Haematological changes including anaemia, increased risk of deep-vein thrombosis (DVT) and susceptibility to disseminated intravascular coagulation
These effects of pregnancy may be overlooked by staff unfamiliar with managing pregnant women. This problem may increase with the separation of anaesthesia and intensive care medicine training in the UK, as non-anaesthetic intensivists are less likely to have spent time on the labour ward during their training.
Finally, there may be psychological problems in the mother who is, or has been, critically ill, both before and after delivery. The fetus is likely to have been affected by her illness, increasing the stress upon her. The ICU environment is a far from ideal place to deliver or care for a baby.
Management options
The CEMD reports emphasise prompt recognition of the deteriorating parturient, early involvement of senior clinical staff and multidisciplinary team working.
Routine ICU support includes prophylaxis against DVT and stress ulcers. Management of any associated organ failure is along standard lines. In severe respiratory failure in pregnancy, early referral to a specialist unit able to provide extracorporeal membrane oxygenation (ECMO) is advised. Premature labour is always a risk of severe maternal illness; however, the use of tocolytic drugs may be considered too risky for the mother. Aortocaval compression must be avoided at all times.
Caesarean section may be required in order to improve the mother’s condition, for example in severe cardiac or respiratory disease or hypertensive disorders. A perimortem caesarean delivery may be required in the event of maternal cardiac arrest; critical care staff should be alerted to this possibility, and appropriate equipment should be readily available.
Postpartum haemorrhage may be severe if a coagulopathy is present. Breast milk may be collected postpartum but may be unsuitable for use because of maternally administered drugs. If breast milk is not collected for neonatal feeding or to maintain lactation until the mother is well enough to nurse, lactation can be suppressed with bromocriptine, although this is not recommended routinely (especially in pre-eclampsia) since hypertension, stroke and myocardial infarction have followed its use.
Regular obstetric review should occur on the ICU, and neonatal support must be accessible. Management specific to the obstetric population must be clearly communicated - for example fluid therapy in pre-eclampsia. Good communication between all the involved clinicians (obstetricians, intensivists, etc.) and between the midwife and ICU nursing staff is vital to ensure that continuity of care is achieved with regard to treatment decisions and information given to relatives. Once discharged from hospital, outpatient obstetric and critical care follow-up should be offered to discuss events and monitor recovery from critical illness.
Key points
• Worldwide, between 0.2 and 9 obstetric patients per 1000 are admitted to the intensive care unit.
• Hypertensive disorders and haemorrhage are the most common causes of admission.
• Basic principles apply, but the special needs of the fetus and the neonate, the mother and her family, and the physiological effects of pregnancy, must be remembered.
• Overall mortality of obstetric ICU admissions in UK series is 3-4%.
Further reading
American College of Obstetricians and Gynecologists. Practice Bulletin No. 158: Critical care in pregnancy. Obstet Gynecol 2016; 127: e21-8.
Gaffney A. Critical care in pregnancy: is it different? Semin Perinatol 2014; 38: 329-40.
Guntupalli KK, Hall N, Karnad DR, et al. Critical illness in pregnancy: part I: an approach to a pregnant patient in the ICU and common obstetric disorders. Chest 2015; 148: 1093-104. Guntupalli KK, Karnad DR, Bandi V, et al. Critical illness in pregnancy: part II: common medical conditions complicating pregnancy and puerperium. Chest 2015; 148: 1333-45.
Intensive Care National Audit and Research Centre. Female admissions (aged 16-50 years) to adult, general critical care units in England, Wales and Northern Ireland, reported as ‘currently pregnant’ or ‘recently pregnant’, 1 January 2009 - 31 December 2012. London: ICNARC, 2013. www .icnarc.org/Our-Audit/Audits/Cmp/Our-National-Analyses/Obstetrics (accessed December 2018).
Plaat F, Wray S. Role of the anaesthetist in obstetric critical care. Best Pract Res Clin Obstet Gynaecol 2008; 22: 917-35.
Royal College of Anaesthetists, Royal College of Obstetricians and Gynaecologists, Royal College of Midwives, et al. Care of the Critically Ill Woman in Childbirth: Enhanced Maternal Care. London: RCoA, 2018. www.rcoa.ac.uk/document-store/enhanced-maternal-care-2018 (accessed December 2018).