Sepsis is the sixth leading cause of death in the 2018 Confidential Enquiries into Maternal Death (CEMD) report. While deaths from indirect causes of sepsis such as influenza and pneumonia seem to be decreasing, the incidence of deaths from pregnancy-related sepsis appears fairly constant.
In recent years there has been a drive for increased awareness of sepsis, and in conjunction with the National Institute for Health and Care Excellence (NICE), the UK Sepsis Trust has released clinical toolkits to aid early recognition and management of sepsis in pregnant women, both in the community and in hospital.
Sepsis in the pregnant population may occur at any time; it may arise from a number of sources and not just the genital tract, and it may range from mild sepsis to severe systemic infection leading to multi-organ failure and maternal or fetal demise. In non-pregnant patients, sepsis is a clinical syndrome manifested by infection and a systemic inflammatory response (which is identified by deviations from normal temperature, heart rate, respiration rate and white blood cell count). Current diagnosis of sepsis is based on the sepsis-related organ failure assessment (SOFA) score, which includes respiratory function, coagulation, liver function, blood pressure, conscious level and renal function. Applying such diagnostic criteria to pregnant patients is difficult, as many of these parameters change in pregnancy; the UK Sepsis Trust has defined sepsis ‘red flags’ to be used in the maternal population (Table 139.1).
Pregnancy is associated with certain risk factors for sepsis, which can be divided into:
• Patient factors, e.g. diabetes, obesity, history of streptococcal B infection or of pelvic infection
• Obstetric factors, e.g. prolonged rupture of membranes, caesarean section, retained products
The most common organisms associated with bacteraemia or sepsis in pregnancy include Escherichia coli, enterococci, Klebsiella, Staphylococcus aureus, Streptococcus pneumoniae, H1N1 and β-haemolytic streptococci. The recognition and aggressive management of developing sepsis, involving a multidisciplinary approach, is thought to be key in preventing morbidity and mortality from a potentially very rapidly evolving condition.
Problems and special considerations
Severe sepsis in obstetrics is usually associated with bacterial infection. Rather than the traditional view that pregnant women are more predisposed to infection owing to a general reduction in immunity during pregnancy, it is now thought that pregnancy may exhibit a modified response to infection owing to an altered reactivity of the immune system that serves to protect both mother and baby.
Table 139.1 Maternalsepsis 'red flags’ (UK Sepsis Trust, 2016)
Responds only to voice or pain/unresponsive
Systolic BP < 90 mmHg (or drop > 40 mmHg from normal)
Heart rate > 130/minute
Respiratory rate > 25/minute
Needs oxygen to keep SpO2 > 92%
Non-blanching rash, mottled/ashen/cyanotic
Not passed urine in last 18 h or urine output < 0.5 ml/kg/h
Lactate > 2 mmol/l
Adapted with permission from UKSepsis Trust, Inpatient maternalsepsis tool: https://sepsistrust.org/wp-content/ uploads/2018/06/Inpatient-maternal-NICE-Final-1107-2.pdf.
The physiological changes that occur in pregnancy, such as vasodilatation and increased blood volume and heart rate, mean that the signs and symptoms of sepsis are often masked; thus, diagnosis and management may be delayed. Severe sepsis associated with bacteraemia may present with non-specific signs such as abdominal pain and diarrhoea, with or without pyrexia. Typically it is rapidly progressive, and when death occurs it may do so within hours of presentation.
A raised white blood cell count, which might support a diagnosis of infection in the nonpregnant population, is less useful in the obstetric setting, since the white cell count is commonly increased by labour and by steroids given to aid fetal lung maturation in prematurity. Thus counts of up to 30 x 109/l are not uncommon in the absence of infection.
Institution of an epidural or spinal block in the presence of systemic infection is potentially very hazardous since cardiovascular compensation, which may be just adequate to maintain blood pressure within normal limits, may be abolished, with catastrophic results as sympathetic blockade develops. In addition, there is a risk of epidural or meningeal infection arising from blood-borne organisms. A more common occurrence is a request for regional analgesia in an otherwise asymptomatic woman with pyrexia (see Chapter 144, Pyrexia during labour).
The fetus is at increased risk from many infections during pregnancy, whether manifested by increased incidence of congenital malformations, premature delivery, the consequences of general maternal illness or neonatal infection. Chorioamnionitis itself has been implicated in causing premature labour; thus prophylactic antibiotics have been studied as a means of delaying onset of labour in premature rupture of membranes.
Management options
Prophylactic intraoperative antibiotic therapy has been shown to reduce the incidence of sepsis following caesarean section and should be routine. Usually this is given by the anaesthetist. Administration has traditionally been delayed until after delivery to avoid passage of drugs to the fetus, and because, should an allergic reaction occur, the baby will already have been delivered. However, recent guidance from NICE recommends administration before skin incision, on the basis of greater efficacy. Great care must be taken when following this advice, since thiopental/antibiotic syringe-swap drug errors are easily made, especially in emergencies.
Developing sepsis is easily missed, even by experienced medical staff. A high index of suspicion is therefore important. Use of a modified early obstetric warning score chart can help identify the deteriorating parturient (see Chapter 156).
It is recommended that the management of septic obstetric patients follows the guidelines of the Surviving Sepsis Campaign, a collaboration between the European Society of Intensive Care Medicine, the Society of Critical Care Medicine and the International Sepsis Forum. These aim to standardise care and improve the outcome in sepsis generally; the main points of care are aggressive resuscitation, adequate oxygenation and appropriate and prompt antibiotic treatment.
Resuscitation with fluids and vasopressors is necessary to ensure oxygenation and prevent tissue hypoxia; noradrenaline is usually the first vasopressor of choice. Appropriate resuscitation before organ failure occurs is thought to improve survival by approximately 20%. Fluid overload is always a concern in obstetric patients because of the haemodynamic changes of pregnancy, especially those that occur in the peripartum period, and because of the use of uterotonic drugs (e.g. oxytocin), which are associated with fluid retention. Thus, some clinicians advocate invasive monitoring with central venous lines, but these are not without hazard (see Chapter 157, Invasive monitoring). Successive CEMD reports have stressed the importance of involving intensivists early in the care of critically ill women, and that ‘intensive care’ can be provided outside the intensive care unit.
Blood culture samples should be taken and intravenous antibiotics administered within the first hour of diagnosis, which is considered the ‘golden hour’. This is thought to be key to improving maternal and fetal outcome; from the recognition of sepsis, each hour’s delay in antibiotic treatment has been associated with an increase in mortality of 8%. It is good practice to seek advice from the microbiology department regarding the most appropriate choice of antibiotics. If there is a focus of infection that can be removed surgically, then this should be done.
When and how to deliver the baby is an obstetric decision, but the discussion should involve the anaesthetist with regard to timing and whether the mother’s clinical condition has been or can be stabilised. The choice of anaesthetic is dependent on each individual case; the presence of systemic infection and a developing coagulopathy secondary to sepsis may preclude the use of a neuraxial technique. Moreover, the risk of cardiovascular block secondary to sympathetic blockade caused by a regional technique should also be considered. General anaesthesia may be the preferred choice of anaesthesia for delivery; however, it must be remembered that general anaesthesia may also result in cardiovascular instability. Invasive blood pressure monitoring and central venous access are useful, regardless of the mode of anaesthesia.
Transfer of the patient to a more appropriate environment, such as the high-dependency or intensive care unit, should be discussed between the obstetrician, anaesthetist and intensivist. Decision to extubate will be influenced by the patient’s condition.
Key points
• Sepsis is the one of the leading causes of death in pregnancy.
• Diagnosis is not always immediate because of the physiological changes in pregnancy, and clinical deterioration may therefore not be recognised until too late.
• Management involves aggressive treatment with fluid resuscitation and cardiovascular support, appropriate antibiotic treatment and adequate oxygenation.
• Early transfer to high-dependency or intensive care facilities may be advisable.
Further reading
Galvagno SM, Camann W. Sepsis and acute renal failure in pregnancy. Anesth Analg 2009; 108: 572-5.
Knight M, Bunch K, Tuffnell D, etal.; MBRRACE-UK. Saving Lives, Improving Mothers’ Care: Lessons learned to inform maternity care from the UK and Ireland Confidential Enquiries into Maternal Deaths and Morbidity 2014-16. Oxford: National Perinatal Epidemiology Unit, University of Oxford, 2018.
Levy MM, Dellinger RP, Townsend SR, et al.; Surviving Sepsis Campaign. The Surviving Sepsis Campaign: results of an international guideline-based performance improvement program targeting severe sepsis. Crit Care Med 2010; 38: 367-74.
Lucas DN, Robinson N, Nel MR. Sepsis in obstetrics and the role of the anaesthetist. Int J Obstet Anesth 2012; 21: 56-67.
Paruk F. Infection in obstetric critical care. Best Pract Res Clin Obstet Gynaecol 2008; 22: 865-83.