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Obstetric emergencies 

Obstetric emergencies
Chapter:
Obstetric emergencies
Author(s):

Heather Baid

, Fiona Creed

, and Jessica Hargreaves

DOI:
10.1093/med/9780198701071.003.0016
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date: 05 May 2021

The pregnant patient in critical care

Admission to critical care

Pregnant women may be admitted to critical care units for a variety of reasons. Admission may be triggered by complications of pregnancy or pre-existing medical conditions. Common causes of critical care admission during pregnancy include:

  • pre-eclampsia or eclampsia

  • postpartum haemorrhage

  • placental abruption

  • amniotic fluid embolism

  • infection

  • cardiac complications

  • severe gestational diabetes

  • stroke.

The effect of critical care on the pregnant mother and fetus will depend upon the severity of the illness. It is important to remember that because care interventions may have a profound impact on both mother and fetus, they must be carefully considered by the critical care team in order to minimize complications.

Additional considerations

The maintenance of fetal oxygenation is an important consideration. Therefore careful attention must be paid to:

  • adequate maternal blood pressure and cardiac output

  • adequate oxygenation

  • adequate perfusion to the fetus

  • appropriate monitoring.

Early involvement of the midwifery and obstetric team is essential, and the decision may be made to monitor the fetus while the mother is critically ill. Fetal monitoring and interpretation of the monitoring remain the responsibility of the midwifery/obstetric team. However, some important issues that critical care staff should be aware of include:

  • normal fetal heart rate (110–160 beats/min)

  • decelerations from baseline may indicate fetal distress

  • abnormal fetal heart rates or tracings require prompt intervention.

Close liaison between critical care staff and the obstetric/midwifery team is vital, and any concerns about the mother or fetus should be escalated immediately, as interventions such as early Caesarean section may be required.

Indications for early Caesarean section

Caesarean section may be indicated for the following reasons:

  • critical deterioration in maternal health

  • death of the mother (in which case it needs to be performed within 4 min of cessation of maternal circulation)

  • instability of the fetus

  • the decision by the team that Caesarean section is safest for mother and fetus.

Caesarean section can normally be considered as an option once the fetus has reached 24 weeks, as it is then considered viable.

In addition to the indications listed on Obstetric emergencies p. [link], Caesarean section may be performed to assist with maternal resuscitation in maternal collapse from 20 weeks’ gestation (see Obstetric emergencies p. [link]).1

Equipment for emergency Caesarean section should be available whenever there is a pregnant patient in the critical care area.

Reference

1 Royal College of Obstetricians and Gynaecologists. Maternal Collapse in Pregnancy and the Puerperium (Green-top Guideline No. 56). RCOG: London, 2011.Find this resource:

Pre-eclampsia and eclampsia

Definition

Pre-eclampsia is defined by NICE as new hypertension presenting after 20 weeks’ gestation with significant proteinuria.2 (Significant proteinuria is diagnosed if the urinary protein:creatinine ratio is higher than 30 mg/mmol or a validated 24-h urine collection result shows more than 300 mg protein.)

It is a relatively common occurrence in pregnancy, affecting 2–8% of all pregnancies. It has associated mortality and morbidity risks to the patient, and is one of the leading causes of maternal death in the UK. The risk to the mother is relatively small if pre-eclampsia occurs after 36 weeks’ gestation, but it increases significantly if it occurs before 33 weeks’ gestation. Complications of pre-eclampsia include:

  • pulmonary oedema

  • seizures (i.e. eclampsia)

  • intracerebral haemorrhage.

Risk factors for the development of pre-eclampsia include:

  • primigravidae

  • multiple pregnancies

  • obesity

  • age > 40 years

  • previous history of pre-eclampsia

  • family history of pre-eclampsia

  • pregnancy interval of more than 10 years

  • diabetes mellitus.

Eclampsia is typically defined as a complication of severe pre-eclampsia, resulting in new onset of grand mal seizure activity and/or unexplained coma during pregnancy or postpartum in a woman with signs or symptoms of pre-eclampsia.

Urgent diagnosis and intervention are required for pre-eclampsia and eclampsia.

Assessment

Assessment of the mother should follow a systematic ABCDE approach (see Obstetric emergencies p. [link]). Two cardinal signs should be present to confirm severe pre-eclampsia requiring admission to a higher level of care. These are:

  • systolic blood pressure > 140 mmHg systolic or 90 mmHg diastolic

  • protein urea > 300 mg in 24 h.

Additional assessment findings may include changes to renal, neurological, abdominal, and haematological function, and may cause:

  • oliguria

  • elevated serum creatinine levels

  • elevated LFTs

  • pulmonary oedema or decreased saturations

  • severe headache

  • visual disturbances

  • seizures

  • epigastric or upper right quadrant pain

  • thrombocytopenia.

NICE3 highlights the need for transfer to higher levels of care if the patient requires:

  • stabilization of blood pressure

  • support of failing systems (haematological, respiratory, or cardiovascular)

  • assessment following neurological changes

  • mechanical ventilation.

Management

Management of pre-eclampsia is based on continuous assessment of the mother and fetus and associated:

  • management of hypertension

  • accurate fluid balance

  • management of complications

  • preparedness for early fetal delivery.

Management of hypertension

NICE3 highlights the need for continuous blood pressure assessment and control of blood pressure using oral or intravenous medication. This may include:

  • labetalol

  • nifedipine

  • hydralazine.

Responses to antihypertensive treatment should be closely monitored, as should adverse complications of treatment for the mother and fetus.

Strict fluid balance

  • Accurate intake and output are essential, and urinary catheterization may be required.

  • Fluid resuscitation may be required if the mother’s blood pressure falls in response to antihypertensive medication (this is especially likely when administering hydralazine).

  • Limit IV fluid to 80 mL/h unless there are ongoing fluid losses or hypotension.

Management of complications

  • The risks and manifestation of ongoing complications should be assessed.

  • Severe hypertension (160/110 mmHg) may require the administration of IV magnesium sulfate, as does the presence of eclamptic convulsions.3

Preparedness for early delivery

  • Steroids should be administered if early delivery is likely to occur at 24–35 weeks’ gestation.

  • Normal delivery can be considered if blood pressure is controlled.

  • Mothers with uncontrolled blood pressure despite medication may require operative delivery.

Eclampsia and pre-eclampsia normally begin to resolve after the removal of the placenta, but it is necessary to continuing monitoring for pre-eclampsia and eclampsia after delivery, as complications can occur and continue for 48–72 h after delivery.

References

2 National Institute for Health and Care Excellence (NICE). Hypertension in Pregnancy: the management of hypertensive disorders during pregnancy. CG107. NICE: London, 2010. Obstetric emergencieswww.nice.org.uk/guidance/cg107Find this resource:

3 National Institute for Health and Care Excellence (NICE). Severe Hypertension, Severe Pre-Eclampsia and Eclampsia in Critical Care. NICE: London, 2011. Obstetric emergencies https://pathways.nice.org.uk/pathways/hypertension-in-pregnancy/severe-hypertension-severe-pre-eclampsia-and-eclampsia-in-critical-care

Further reading

European Society of Intensive Care Medicine. Obstetric Critical Care: clinical problems. Obstetric emergencieshttp://pact.esicm.org/media/Obstetric%20critical%20care%2030%20April%202013%20final.pdf

Royal College of Obstetricians. Obstetric emergencieshttps://www.rcog.org.uk/

HELLP syndrome

Definition

HELLP is an acronym that stands for Haemolysis, Elevated Liver Enzymes and Low Platelets. It is considered to be a varying presentation of severe pre-eclampsia. It can arise either in the antenatal period or shortly after delivery. Mortality and morbidity rates are high. The pathophysiology relating to HELLP is unclear. It may occur without hypertension and other signs of pre-eclampsia.

Assessment

Some of the signs and symptoms are related to vasospasm of the hepatic vessels. They include:

  • nausea

  • vomiting

  • abdominal pain (typically epigastric or right upper quadrant pain)

  • generalized oedema

  • malaise.

Laboratory investigations may indicate:

  • reduced haematocrit

  • elevated bilirubin

  • reduced platelet count

  • elevated AST/ALT and APT.

Complications include:

  • DIC (see Obstetric emergencies p. [link])

  • pulmonary oedema

  • hepatic dysfunction

  • hepatic rupture and infarction.

Management

Some of the management is similar to that of pre-eclampsia. Treatment should focus on:

  • control of symptoms

  • stabilization of the patient

  • observing for signs of haemorrhage (see Obstetric emergencies p. [link])

  • management of bleeding or transfusion of blood products (see Obstetric emergencies p. [link])

  • urgent Caesarean section.

Postpartum haemorrhage

Definition

Postpartum haemorrhage (PPH) may be primary or secondary. Primary PPH is the loss of 500 mL or more of blood from the genital tract within 24 h of the birth of the baby. According to the Royal College of Obstetricians and Gynaecologists, PPH can be minor (500–1000 mL) or major (> 1000 mL). Secondary PPH is defined as abnormal or excessive bleeding from the birth canal between 24 h and 12 weeks postnatally.4

PPH is the leading cause of maternal death worldwide, and accounts for 30% of maternal deaths. Around 1% of deliveries are associated with PPH.

Risk factors include:

  • previous PPH

  • increased BMI

  • four or more previous babies

  • antepartum haemorrhage

  • over-distended uterus

  • uterine abnormalities

  • low-lying placenta

  • women over 35 years of age.

Labour risks include:

  • induction

  • prolonged stages of labour

  • use of oxytocin

  • operative birth.

Causes of PPH include:

  • tone—uterine atony (inability to contract)

  • trauma—tear of uterus, cervix, or vaginal wall

  • tissue—retained placenta

  • thrombin—coagulation deficits.

Assessment

Assessment of the mother should follow a systematic ABCDE approach (see Obstetric emergencies p. [link]). Particular attention must be focused on assessment of signs of hypovolaemic shock or massive haemorrhage. This will include:

  • obvious signs of haemorrhage (see Obstetric emergencies p. [link])

  • hypotension

  • tachycardia

  • tachypnoea

  • increased capillary refill time

  • decreased urine output

  • increased SVR

  • decreased level of consciousness.

Management

Management is based on accurate assessment, fluid resuscitation, stabilization of the patient, intervention to stop further bleeding, and monitoring for complications arising from PPH. Note that accurate assessment of blood loss in PPH is difficult, as blood loss may be concealed and other fluids such as amniotic fluid may also be present.

Assessment of the patient

Timely and accurate assessment using an ABC approach is required to determine the consequences of PPH for the mother.

Fluid resuscitation

Massive fluid resuscitation may be required, using blood products, colloids, and crystalloid.

  • Guidelines relating to massive haemorrhage should be followed (see Obstetric emergencies p. [link]).

  • Two wide-bore peripheral cannulae should be inserted.

  • Central line insertion may also be required.

  • FBC and coagulation tests will be needed.

  • Techniques to increase uterine contraction may be required.

Stabilization of the patient

Interventions and/or medications may be needed to stabilize the patient. These may include:

  • high-flow oxygen in self-ventilating patients

  • mechanical ventilation if the patient’s condition is poor

  • vasopressors to maintain appropriate cardiac output and blood pressure

  • invasive blood pressure monitoring (see Obstetric emergencies p. [link])

  • measurement of cardiac output (see Obstetric emergencies p. [link]).

Intervention to stop further bleeding

If bleeding is not stopped by conservative measures, administration of haemostatic agents may be recommended.

If this fails, surgical or radiological intervention may be needed. This may include:

  • manual removal of the placenta if it has not already been delivered

  • uterine tamponade

  • haemostatic brace suturing (e.g. B-Lynch suture)

  • surgical ligation of uterine and/or internal iliac arteries

  • radiological embolization

  • hysterectomy.

Monitoring for complications

There are several potential complications of PPH. Some of these relate to massive blood transfusion, while others are directly linked to the PPH. It is important that the critical care nurse closely monitors the patient for these complications. They include:

  • acute lung injury

  • electrolyte imbalance

  • coagulopathies

  • increased risk of thrombosis

  • increased risk of acute kidney injury

  • Sheehan’s syndrome (damage to the anterior lobe of the pituitary gland, which inhibits lactation).

Reference

4 Royal College of Obstetricians and Gynecologists (RCOG). Postpartum Haemorrhage, Prevention and Management (Green-top Guideline No. 52). RCOG: London, 2011.Find this resource:

Further reading

Pollock W and Fitzpatrick C. Pregnancy and postpartum considerations. In: D Elliott, L Aitken and W Chaboyer (eds) ACCN’s Critical Care Nursing, 2nd edn. Elsevier Australia: Chatswood, NSW, 2012. pp. 710–45.Find this resource:

Amniotic fluid embolism

Definition

Amniotic fluid embolism (AFE) is a rare and potentially catastrophic complication of pregnancy. Its incidence is about 8–10 per 100 000 pregnancies. It predominantly occurs as a result of labour, but can occur throughout pregnancy. Its aetiology is not known, but it is suggested that exposure of amniotic fluid to the maternal circulation is the catalyst for AFE. Recent discussions relating to AFE have likened its consequences to a severe anaphylactoid response, and the term ‘anaphylactoid syndrome of pregnancy (ASP)’ has been suggested. Regardless of the mechanism involved, mothers with AFE/ASP will deteriorate rapidly, and require urgent medical intervention.

Risk factors include:

  • induction of labour

  • forceful uterine contractions

  • Caesarean section or instrumental delivery

  • placenta praevia and abruptio placentae

  • cervical lacerations

  • eclampsia.

Assessment

A thorough assessment of the mother with AFE is essential, and it should follow a systematic ABCDE approach (see Obstetric emergencies p. [link]). The symptoms are likely to present in phases.

  • The initial phase is characterized by disturbances in respiratory function and severe pulmonary oedema.

  • The second stage is characterized by cardiovascular changes secondary to left-sided cardiac failure.

  • Finally, haemorrhagic complications may follow, causing DIC (see Obstetric emergencies p. [link]).

The patient is likely to present with:

  • acute dyspnoea

  • severe hypoxaemia

  • pulmonary oedema

  • ARDS

  • hypotension

  • coagulopathies

  • severe haemorrhage (see Obstetric emergencies p. [link]).

Management

Management is mostly supportive in nature and directed towards failing systems.

  • Intubation is likely to be needed, due to respiratory failure.

  • Mechanical ventilation may be required, and it may be necessary to use high concentrations of oxygen to correct the hypoxaemia.

  • In severe cases, nitric oxide therapy or ECMO may be needed.

  • Haemodynamic monitoring and restoration of blood pressure are required.

  • Fluid resuscitation should follow massive haemorrhage protocols (see Obstetric emergencies p. [link]).

  • Strict fluid assessment is required.

  • Support of failing cardiovascular status with inotropes and vasopressors may be necessary.

  • DIC is a likely consequence, so blood, blood components, and clotting factors will be required to reduce the effects of DIC (Obstetric emergencies p. [link]).

  • Delivery of the fetus should be expedited if AFE occurs antepartum.

Further reading

European Society of Intensive Care Medicine. Obstetric Critical Care: clinical problems. Obstetric emergencieshttp://pact.esicm.org/media/Obstetric%20critical%20care%2030%20April%202013%20final.pdf

Pollock W and Fitzpatrick C. Pregnancy and postpartum considerations. In: D Elliott, L Aitken and W Chaboyer (eds) ACCN’s Critical Care Nursing, 2nd edn. Elsevier Australia: Chatswood, NSW, 2012. pp. 710–45.Find this resource:

Cardiac arrest in pregnancy

Special precautions

Significant physiological changes in cardiac output, oxygenation, and circulatory volume occur in pregnancy, and these need to be considered in the event of a maternal cardiac arrest. In addition, the impact of the uterus in the later stages of pregnancy can adversely affect cardiac output.

Although cardiac arrest in pregnancy is relatively rare (1 in 300 000 deliveries), common causes have been identified. These include:

  • cardiac disease

  • pulmonary embolus

  • severe hypertension

  • haemorrhage

  • severe infection

  • AFE/ASP

  • ectopic pregnancy.

Resuscitation following cardiac arrest will largely follow the guidelines for general resuscitation (see Obstetric emergencies p. [link]). However, there are some important modifications of this that should be considered.

  • When summoning immediate assistance it is important to contact an obstetrician as well as the cardiac arrest team.

  • CPR should commence as soon as possible, and the evidence suggests that good-quality cardiac compressions increase the likelihood of success.

  • After 20 weeks’ gestation, care should be taken with maternal positioning. The gravid uterus may compress the inferior vena cava and decrease venous return and preload. The mother should therefore be positioned to avoid this. The uterus should be manually displaced, and once this has been done the mother should be placed in a position that provides a left lateral tilt (with pillows and/or specially designed wedges). The tilt should be approximately 15–30° and should facilitate Caesarean delivery if this is deemed necessary.

  • Equipment should be available for an emergency Caesarean section if this is deemed appropriate by the medical team.

  • If there is no response to correctly performed CPR within 4 min of maternal collapse, or if resuscitation is continued beyond this in women beyond 20 weeks’ gestation, delivery should be undertaken to assist maternal resuscitation. This should be achieved within 5 min of the collapse.5

  • As there is an increased risk of pulmonary aspiration, early tracheal intubation is recommended.

Reference

5 Royal College of Obstetricians and Gynaecologists (RCOG). Maternal Collapse in Pregnancy and the Puerperium (Green-top Guideline No. 56). RCOG: London, 2011.Find this resource:

Further reading

Resuscitation Council (UK). Cardiac Arrest in Special Circumstances. Obstetric emergencies https://lms.resus.org.uk/modules/m10-v2-cardiac-arrest/10346/resources/chapter_12.pdf