Evacuation of retained products of conception (ERPC) may be required at any stage of pregnancy, but it occurs most commonly in early pregnancy following incomplete miscarriage or early fetal demise. It is also required during the puerperium following retention of placental tissue (see Chapter 40, Removal of retained placenta and perineal suturing).
Problems and special considerations
ERPC following spontaneous abortion at 8 weeks’ gestation may be a minor routine gynaecological emergency for the anaesthetist, but the mother may have lost a much- wanted baby.
The urgency of the procedure varies greatly. The majority of ERPCs are performed as scheduled emergencies in fit young women, and this may lull the inexperienced anaesthetist into a false sense of security. Death may occur from spontaneous abortion; blood loss may be heavy and is frequently underestimated.
The possibility of coexisting uterine or systemic sepsis must always be considered, especially in postpartum ERPC or in a repeat procedure following incomplete evacuation.
Management options
Diagnostic ultrasound scanning is frequently used to confirm a non-viable early pregnancy or the presence of retained placental tissue. Transabdominal and transvaginal ultrasonography are now considered to be complementary to each other, with most women requiring a transvaginal ultrasound. Most units now operate a policy of fully assessing mothers on the day of admission in an early pregnancy advisory unit (EPAU), allowing them home and re-admitting them the following day for planned ERPC. This facilitates planning of medical and nursing staffing levels, reduces prolonged periods of waiting and starvation for the mother, and can be economically advantageous.
Expectant management may be offered as a first-line management strategy, unless there are particular risks of haemorrhage or infection. Medical treatment is increasingly used, and this enables women to be allowed home after treatment with prostaglandin analogues to await events. Analgesia and antiemetics should be offered as required. Non-surgical methods are associated with longer and heavier bleeding, and 15-50% of these women will need surgical management if the products of conception are not fully expelled. If required, surgical management of miscarriage may occur under local, regional or general anaesthetic.
Preoperatively, a full assessment is required. Assessment of blood loss may be difficult; fit young women may lose a significant proportion of their blood volume without becoming hypotensive. Tachycardia should alert the anaesthetist to possible hypovolaemia. Signs of sepsis should be sought, and prophylactic antibiotics may be considered.
General anaesthesia is most commonly used in the UK, although in the absence of uncorrected hypovolaemia or other contraindications, regional anaesthesia is entirely suitable. The puerperal mother in particular may wish to stay awake if offered a choice, and she should be advised to do so if she is at risk of regurgitation.
Rapid-sequence induction of general anaesthesia is indicated for the non-fasting mother requiring urgent surgery (uncommon) and for the mother who is at risk of regurgitation (see Chapter 59, Aspiration of gastric contents). Anaesthesia using a laryngeal mask airway or facemask using any standard day-case anaesthetic technique is appropriate for the majority of women needing ERPC. Sedative premedication is rarely needed. Intravenous anaesthesia, for example with propofol, or inhalational anaesthesia, are acceptable, though if the latter is used high concentrations of volatile anaesthetic agents (> 1 minimum alveolar concentration (MAC)) should be avoided because of the uterine relaxation that may ensue.
Oxytocic drugs may be requested by the surgeon, although there is little evidence for their efficacy at gestations of less than 15 weeks. A single intravenous bolus of 5 U oxytocin usually suffices. Ergometrine causes increased intracranial and systemic pressure, and nausea and vomiting, and should not be used routinely.
Spinal anaesthesia produces more rapid and dense anaesthesia than epidural anaesthesia, and an anaesthetic level of at least T8 is recommended. Clinical experience shows that the traditionally taught anaesthetic level of T10 is insufficient to prevent pain occurring when the uterine fundus is manipulated or curetted.
Postoperatively, the aim is rapid recovery and discharge home. Requirement for postoperative analgesia rarely exceeds simple non-opioid drugs. Non-steroidal antiinflammatory agents may be beneficial in relieving uterine cramps. Routine administration of antiemetics should be considered, since these women are at risk of postoperative nausea and vomiting. Thromboprophylaxis may be indicated depending on risk factors.
Key points
• A sensitive and sympathetic approach to the mother is necessary.
• Prolonged preoperative waiting and starvation reflects poor communication and inefficiency.
Further reading
National Institute for Health and Care Excellence. Ectopic Pregnancy and Miscarriage: Diagnosis and Initial Management. Clinical Guideline 154. London: NICE, 2012. www.nice.org.uk/guidance/c g154 (accessed December 2018).