5.1 The Breathless Pregnant Woman
EXPLANATION OF CONDITION
Breathlessness is the sensation of feeling out-of-breath or unable to catch your breath. The normal respiratory rate is 12–20 breaths/minute at rest. A persistent respiratory rate at rest >24 breaths/minute is abnormal1.
Breathlessness in pregnancy is extremely common and may reflect the normal anatomical and physiological changes that occur in pregnancy or may be a consequence of an underlying pathology.
The normal changes of pregnancy that may influence the respiratory rate, perception of breathlessness and decreased exercise capacity comprise:
- Increase in weight
- Elevation of the diaphragm by up to 4 cm, although its excursion is not impaired
- Capillary enlargement throughout the respiratory tract with increased mucosal oedema and hyperaemia
- Increased transverse and antero-posterior diameter leading to an increase in the sub-costal angle and up to 7 cm increase in chest circumference
- 20% increase in oxygen consumption
- 15% increase in maternal metabolic rate
- Increased tidal volume but normal respiratory rate
- Increased progesterone leading to hyperventilation
- Increased free cortisol
Pathological Causes of Breathlessness
- Respiratory disease:
- asthma
- chest infection and/or pneumonia
- thrombo-embolic disease
- interstitial lung disease, e.g. sarcoid or secondary to a connective tissue disorder
- pneumothorax
- amniotic fluid embolism
- asthma
- Cardiac disease:
- arrhythmias
- ischaemic heart disease
- cardiomyopathy
- arrhythmias
- Endocrine disease:
- diabetes mellitus leading to hyperventilation in the setting of acute ketoacidosis
- acute thyrotoxicosis
- diabetes mellitus leading to hyperventilation in the setting of acute ketoacidosis
- Haematological:
- chronic anaemia
- acute haemorrhage
- chronic anaemia
- Renal disease:
- hyperventilation to compensate for metabolic acidosis secondary to acute renal failure
This list is not exhaustive and further details on all of these conditions are outlined in the relevant chapters.
COMPLICATIONS
Breathlessness is experienced by 60–70% of women during pregnancy, especially in the second and third trimesters. Physiological breathlessness does not cause complications.
Breathlessness due to a pathological cause can result in complications and these are detailed in the chapters relating to specific conditions.
NON-PREGNANCY TREATMENT AND CARE
Breathlessness is a normal physiological response to exercise. However, breathlessness at rest and breathlessness in response to minimal exercise out of proportion to an individual’s normal level of fitness needs to be investigated. When a pathological cause of breathlessness is suspected, a detailed history and examination need to be taken.
First line investigations should include:
- Full blood count
- Renal function
- Glucose
- Simple lung function tests
- Urine dipstick
- Chest radiograph
Additional tests may include:
- D-dimers
- ECG
- Full lung function tests
- Thyroid function tests
- Computed tomography of the chest, with or without pulmonary angiography
- Echocardiogram
- Detailed cardiopulmonary exercise testing
Treatment should be directed at the specific cause. In the setting of hyperventilation, physiotherapy to instruct patients in breathing control techniques may be of benefit.
PRE-CONCEPTION ISSUES AND CARE
Whether the cause of breathlessness has pre-conception implications is dependent upon the cause of the breathlessness, and the reader needs to refer to the individual chapters on the management of specific conditions that can cause breathlessness.
Strongly encourage smoking cessation.
- If a pathological cause is suspected the woman needs to be investigated2 and, in particular, conditions that are more common in pregnancy, e.g. pulmonary emboli, need to be considered
- Treatment needs to be specific for the cause of breathlessness but the potential risks of treatment need to be considered, e.g. antibiotic choice for pneumonia
- Details of the management of specific conditions are outlined in the other relevant chapters
- The midwifery care needs to be tailored to the woman’s needs3. This should be focused on education through antenatal care and support for physiological breathlessness. With pathological breathlessness this will involve referral to a consultant obstetrician to assess the woman’s case and need for further investigations
- Regular antenatal appointments with the community midwife to ensure that the baby is not compromised and to ensure the woman’s health does not deteriorate
- At all stages of pregnancy, whether at the booking visit or mid-trimester the midwife must recognise any complications and give full explanations of these and potential consequences to the mother. This is important in order for her to make informed decisions about where she may want to give birth. If she had intended to give birth at home or in a midwifery-led unit this may not be the most appropriate place
- In the setting of pathological breathlessness, augmented labour or early caesarean section may need to be considered
- On admission to delivery suite the midwife needs to make an initial assessment of her immediate condition and needs
- This should involve basic observations – recording of maternal pulse, blood pressure, temperature and respiratory rate
- Take a detailed history taking into account any investigations which may recently have been carried out
- Carry out abdominal palpation and auscultation of the fetal heart. If maternal or fetal observations are outside of normal parameters then the midwife should refer to a doctor for further advice. This is also true if the woman has been admitted to a midwifery-led unit or is labouring at home
- If pathological breathlessness is suspected then the baby needs to be continuously monitored with maternal vital signs recorded at more frequent intervals
- Postpartum breathlessness should be taken seriously
- It is important to be mindful of the potential pathological causes of postpartum breathlessness, e.g. pulmonary emboli or anaemia
- A low threshold for seeking further medical advice is required
- The midwife needs to be mindful of the potential seriousness of a woman with postpartum breathlessness
- A mother with signs of breathlessness should not be discharged from hospital without having first had a medical review
- Once home, thorough postnatal examinations with astute observation of the physical condition should be conducted. Where necessary instigate appropriate investigations and refer to the primary care physician, or as an emergency to hospital, as warranted
5.2 Asthma
EXPLANATION OF CONDITION
Asthma is a common condition in western societies, affecting 5–15% of the population and its prevalence and incidence are increasing.
Asthma is a chronic inflammatory disease of the airways, which is characterised by intermittent episodes of wheeze, shortness of breath, chest tightness and cough. It is a variable disease in which, in response to certain stimuli, or triggers, inflammation and structural changes occur in the lungs. This causes airway hyper-responsiveness and variable airflow obstruction leading to the symptoms described. Symptoms of asthma tend to be variable, intermittent and worse at night.
Patients suffer from flare-ups or exacerbations of their disease either in response to an acute infection, which is usually viral in origin, or due to poor control of their airway inflammation.
Triggers for Asthma
- Smoking
- Allergens, e.g. house dust mite, pollen, etc.
- Exercise
- Occupational exposure
- Pollution
- Drugs, e.g. aspirin, beta-blockers, including eye drops and as part of an anaphylactic response to other drugs
- Food and drinks such as dairy produce, alcohol, peanuts and orange juice
- Additives such as monosodium glutamate and tartrazine
- Medical conditions, e.g. rhinitis and gastric reflux
- Hormonal, e.g. pre-menstrual conditions and pregnancy
There is a strong link between asthma and atopy (the tendency to become sensitised to allergens and to develop allergic disease).
COMPLICATIONS
Asthma is a major burden not only on the patient, but also for health care provision and on society, causing time off work.
There are currently around 1500 asthma deaths per year. Many factors are believed to be responsible for these, including:
- A long history of asthma
- Marked peak flow variability
- Non-adherence to medication, especially inhaled corticosteroids
- Psychosocial problems
- Previous admissions with asthma, particularly if ventilated or if life-threatening features were present
The majority of asthma deaths occur in patients who present late for treatment, often despite having symptoms. Poor patient education, an underestimation of the severity of the asthma by both the patient and the health care professional, and inappropriate treatments have also been implicated in asthma deaths. On occasion, fatal attacks occur rapidly with little time for intervention, but this is uncommon3.
NON-PREGNANCY TREATMENT AND CARE
British Thoracic Society (BTS) guidelines for the management of asthma have been in existence since the 1990s. These are now living guidelines and can be accessed through the BTS website (www.brit-thoracic.org.uk).
Aims of Asthma Management
- Control of symptoms
- Prevention of exacerbation
- Achievement of the best pulmonary function for the patient with minimal side effects
Good Asthma Care4
- Correct diagnosis: a history consistent with a diagnosis of asthma, supported by objective tests and after consideration of possible differential diagnoses
- Control of symptoms
- Pharmacological management – in a stepwise manner
- Non-pharmacological management: avoidance of triggers3,5
- Smoking cessation advice: to avoid fixed airway obstruction in later life6
- Self-management: essential for any chronic disease5
In a third of patients symptoms will get better, in a third symptoms will worsen and in a third they will stay the same.
PRE-CONCEPTION ISSUES AND CARE
It is important that women with asthma are optimally managed in the pre-conception period. The treatment may require review, and the woman might need to be re-referred to a specialist clinic. The Royal College of Physicians suggests three questions3, which can be incorporated as part of the woman’s assessment:
- Have you had difficulty sleeping because of your asthma symptoms, including a cough?
- Have you had your usual asthma symptoms during the day, such as a cough, wheeze, chest tightness or breathlessness?
- Has your asthma interfered with your usual activities, e.g. housework, work, school, etc.?
- Poorly-controlled asthma confers an increased risk to the mother and fetus2,6
- Asthmatic women are more at risk of low birth weight neonates, pre-term delivery and complications such as pre-eclampsia, especially in the absence of actively managed asthma treated with inhaled corticosteroids2
- There is no contraindication to most first-line treatments for asthma when used in pregnancy
- Smoking cessation is an important part of general obstetric advice, but is important in asthma to reduce symptoms and the efficacy of inhaled corticosteroids is reduced in asthmatics who smoke
- Carrying a female fetus has been associated with worse maternal asthma. (Kwon HL, Belanger K, Holford TR et al. in BTS Sign)
- Studies reported in the BTS guidance suggest 11–18% of pregnant women with asthma will have at least one emergency department visit for acute asthma and of these 62% will require admission
- It is important to optimise the control of the woman’s asthma, as this will reduce the potential of asthma-related morbidity during pregnancy. This includes addressing issues related to trigger factors and adherence to medication
- Inhaled corticosteroids alone or in combination with long-acting bronchodilators are safe in pregnancy
- Leukotriene antagonists are relatively contraindicated in pregnancy due to the lack of information about possible teratogenic effects. These medications are rarely a critical part of asthma care and therefore should not be initiated in pregnancy. Alternative therapy should be considered
- Oral corticosteroids should be used for acute severe exacerbations
- Maintenance systemic corticosteroids should be reserved for women with severe refractory asthma and need to be reviewed by respiratory and obstetric specialists
- Pregnancy does not appear to have a consistent effect on asthma control, which can either worsen or improve. Hence, it should be stressed to the woman that well-controlled asthma is better for baby and pregnancy outcomes
- Explain that asthma medication is generally safe in pregnancy
- Education about good control and adherence to medication is an essential part of early antenatal care8
- In unstable asthma, shared care with obstetrician, midwife and GP is advisable
- Advise women who smoke about the dangers and give appropriate advice about smoking cessation
- Encourage attendance at parent-craft and relaxation classes
- Reinforce health education advice with appropriate leaflets (see Appendix 5.2.1 for an example)
- Acute, severe or life-threatening exacerbations of asthma during labour are extremely rare
- Women who have been on regular oral steroids may require hydrocortisone during labour
- Ergometrine6, Syntometrine and prostaglandin may cause bronchoconstriction and should be used with caution
- In the absence of acute asthma, caesarean section should only be carried out when indicated
- If anaesthesia is required then an epidural is preferential to a general anaesthetic6
- Advise women that acute asthma is rare in labour
- Women should continue their usual asthma medications in labour
- A mother who has well-controlled asthma should be able to have low risk care, with labour managed normally by the midwife
- Normal pain relief can be given and Entonox is considered safe6
- Syntocinon is the preferable drug for active third stage management
- Women need to continue on their regular medication
- It is unusual for asthma to become uncontrolled in the immediate postpartum period
- Generally there are no changes in therapy requirements
- Breast-feeding should be discussed in the antenatal period for the mother to gain greater awareness of the long-term health benefits of breast-feeding and feel more confident to try breast-feeding
- Advise the mother that food allergy appears less likely if foods are introduced at a later stage
- As outlined for medical care above, standard asthma therapy can be used as normal during breast-feeding6
5.3 Pneumonia and Chest Infections
EXPLANATION OF CONDITION
Pneumonia is an acute infection within the lower respiratory tract occurring twice as often in the winter months as in the summer.
COMPLICATIONS
Most cases of pneumonia are not severe and can be easily managed at home with appropriate rest and, if necessary, antibiotics. Complications are unusual but include:
- Severe respiratory failure requiring ventilatory support and admission to intensive care
- Parapneumonic pleural effusion and empyema which may require pleural intubation and drainage and sometimes surgery for decortication
- Abscess formation and embolic abscesses
- Generalised septicaemia
NON-PREGNANCY TREATMENT AND CARE
British Thoracic Society guidelines for the management of community-acquired pneumonia1 have been in existence since the 1990s. These are now living guidelines and can be accessed through the BTS website (www.brit-thoracic.org.uk).
The treatment of pneumonia is guided by an assessment of the severity of the pneumonia and knowledge of the likely causative pathogens1. This is often influenced by host factors, epidemiological or circumstantial factors and geographical variations.
In adults, 70% of community-acquired pneumonia cases are caused by bacteria; atypical bacteria cause 20% of cases, and 10% of cases are viral. Streptococcus pneumoniae is the commonest pathogen found in around half of identified cases. Other pathogens will vary in importance in relation to host or environmental factors.
Hospital-acquired pneumonia is unusual in pregnancy and mostly affects the elderly in hospital with multiple medical problems. Hospital-acquired pneumonia is often due to the aspiration of bacteria which then colonises the upper respiratory tract, often in association with impaired immunological and mechanical host defences2.
Assessment
Severity of pneumonia is assessed by scoring one point for each of these factors that are present1:
- Confusion
- Urea >7 mmol/l
- Respiratory rate ≥30/min
- Blood pressure (systolic <90 mmHg or diastolic ≤60 mmHg)
- Age ≥65 years
Interpretation of score:
- 0–1: likely suitable for home treatment
- 2: consider supervised hospital treatment
- short stay in-patient
- hospital supervised out-patient
- short stay in-patient
- >3: manage in hospital as severe pneumonia
- 4–5: assess for intensive care unit admission
Treatment
Treatment includes supportive care such as bed-rest, analgesia, anti-pyretics, fluids and oxygen if required. In addition, antibiotics are usually given empirically, guided by the severity of the pneumonia, but if there is microbiological confirmation of the causative organism and sensitivities the antibiotic therapy needs to be adjusted accordingly.
The empirical antibiotics of choice, based on severity, are as outlined below1:
- Home-treated, not severe: oral amoxicillin or, if penicillin allergic, oral erythromycin or clarithromycin
- Hospital-treated, not severe (admitted for non-clinical reasons or previously untreated in the community): as for home-treated, not severe
- Hospital-treated, not severe:
- either oral amoxicillin plus erythromycin or clarithromycin 500 mg bd
- or, if intravenous therapy is needed, use ampicillin plus erythromycin/clarithromycin
- in cases of penicillin allergy, or where penicillin has already been given, treat with either levofloxacin or moxifloxacin
- either oral amoxicillin plus erythromycin or clarithromycin 500 mg bd
- Hospital-treated, severe: intravenous co-amoxiclav or cefuroxime plus erythromycin or clarithromycin
- in cases of penicillin allergy use levofloxacin
PRE-CONCEPTION ISSUES AND CARE
Pneumonia is an acute infection and not a chronic condition and therefore does not have significant pre-conception effects. However, antibiotics do reduce the efficacy of the oral contraceptive pill and women need to be advised about alternative contraception whilst treated with antibiotics.
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