Spontaneous pneumothorax in the third trimester of pregnancy
- Abriel Avital,
- Published 18 November 2009
The present report concerns a young woman previously diagnosed as having childhood asthma who presented with a secondary spontaneous pneumothorax during the third trimester of pregnancy; at term a caesarean section was recommended for safety reasons. Post partum a severe fixed ventilatory defect unresponsive to inhaled bronchodilator and a short oral course of steroids ruled out asthma. Diffuse bronchiectasis was found on her chest CT scan, although this was not evident clinically. Known aetiologies for diffuse bronchiectasis (cystic fibrosis, anti-α1 antitrypsin deficiency, rheumatic diseases, mycobacterial infections, childhood infections and immune deficiencies) were ruled out. Therefore it is believed her bronchiectasis was idiopathic or congenital. No recommendations from recent guidelines on how to manage labour in a woman after a spontaneous pneumothorax could be found. However, a literature search revealed that pregnant women usually experience primary pneumothorax and may continue in natural labour; however, it is unknown how best to manage a woman with secondary spontaneous pneumothorax.
Several guidelines have been published on the management of patients with spontaneous pneumothorax (SP).1,2 SP is more frequent among men; women accounted for only 27.8% in a large group of Israeli patients and none was pregnant.2,3 The younger age group (15–34 years) predominantly has primary SP without underlying lung disease in contrast to older patients who usually have secondary SP due to various lung conditions.2
No recommendation is available as to how to manage a pregnant woman with a third trimester pneumothorax, and as to whether she should be allowed to continue with natural labour and childbirth and whether she should be evaluated for an underlying lung condition. We report on such a patient and review the available case reports.
A 17-year-old Bedouin woman, primigravida, was admitted in the 36th week of gestation with shortness of breath and right-sided chest pain of 3 days duration.
She had had bronchial asthma from 7 months of age. As a toddler she had two admissions; one with Haemophilus influenzae pneumonia and one to the paediatric intensive care unit for acute exacerbation of asthma aged 23 months. She denied having had recurrent childhood respiratory tract infections. In recent years she had been treated with a combination inhaler containing fluticasone 500 μg and salmeterol 50 μg/dose twice daily, and inhaled salbutamol as needed; she reported no limitations in her daily activities. On admission her shortness of breath was different from her usual experiences when having an acute asthma attack.
She had conceived naturally and had had an uneventful pregnancy while continuing her asthma medications. She did not smoke.
On admission her respiratory rate was 26 breaths/min and she had an oxygen saturation of 93% on ambient air. She was afebrile with a blood pressure 128/66, pulse was 100 beats/min and regular. She had diffused wheezing bilaterally and reduced lung sounds over the right hemithorax. Obstetric examination showed a normal pregnancy for the gestational age.
Her arterial blood gases while receiving oxygen (FiO2=0.3) revealed partial CO2 (pCO2): 3.879 kPa (29.1 mm Hg), pO2: 18.1 kPa (135.7 mm Hg), O2 saturation: 99.7%. Her haemoglobin, white blood cell count, platelets, kidney function and electrolytes were normal. Due to her respiratory distress a chest x ray in the supine position covering her womb was performed, showing a right-sided pneumothorax with a rim of 1.8 cm without shifting of the mediastinum.
She received oxygen (FiO2=0.3), nebulised salbutamol and ipratropium bromide. An intercostal tube was inserted and sealed under water for 3 days; when air leakage ceased it was removed. On discharge she received a recommendation for a pulmonary consultation; 4 weeks later (40 weeks of gestation) she was admitted in labour with ruptured membranes. The pulmonologist recommended performing a caesarean section to prevent recurrent pneumothorax. She was prepared for surgery with intravenous 80 mg methylprednisolone and underwent a caesarean lower segment transverse section with a spinal block. A healthy baby boy was delivered weighing 2510 g with Apgar scores of 9 and 10 after 1 and 5 min, respectively.
At 2 months post partum she was examined in the outpatient pulmonary clinic feeling well and continuing use of her inhaler; a repeat chest x ray was normal. Her pulmonary function tests showed a severe obstructive ventilatory defect with forced expiratory flow in the first second (FEV1): 0.72 litres (24% predicted for age and height), forced vital capacity (FVC): 1.41 litres (45% predicted), FEV1/FVC ratio: 51% and pulse oximetry saturation: 95%. After inhaled bronchodilator and a course of systemic oral steroid for 12 days her pulmonary function tests confirming a severe chronic obstructive lung disease without reversibility.
A CT scan of her chest (fig 1) revealed bilateral cystic diffuse bronchiectasis without consolidation, pleural effusion and lymphadenopathy; no fibrosis was evident. She underwent a sweat test and α1 antitrypsin, both was normal. The sputum was negative for acid-fast bacilli. Her rheumatic factor, anti-nuclear factor and complement C3 and C4 were in normal ranges, ruling out collagen vascular diseases. Her immunoglobulins were not reduced. She continues treatment with her combination inhaler with fluticasone 500 μg and salmeterol 50 μg/dose twice daily.
We report a young woman who experienced SP during the 36th week of pregnancy. The need for removal of pleural air depends on the cardiopulmonary condition of the patient and whether a tension pneumothorax develops.1,2 Our patient was quite symptomatic and had signs of respiratory distress (saturation 93%, respiratory rate 26 and pulse 100/min), and an intercostal tube was inserted.
During pregnancy, to provide sufficient oxygen to the fetus increased ventilation is necessary. This is accomplished by increased tidal volume and respiratory rate as the functional residual capacity gradually decreases from the influence of the growing womb. The ventilatory needs are even higher during labour, with oxygen consumption increasing more than 50%.2 When a SP causes ventilatory compromise it adversely influences the outcome for mother and fetus, in particular when secondary SP occurs.2 A recent case series estimated that in the UK there was 1 SP event among 10 000 deliveries.4 However there is no recommendation in the recent guidelines on how a pregnant woman after SP should be managed when labour starts.1,2
On reviewing case series of 48 patients with SP, their mean age was 26.4 years and SP occurred at a mean gestational age of 24.1 weeks.4 In all, 7 women (14.6%) were 19 years of age or younger and had SP at 32.7 weeks of gestation, 29 women (60.4%) were aged 20–29 with SP occurring at 20.8 weeks of gestation and 12 women (25%) in the age group 30–39 years had SP at 25.6 weeks gestation.4 The youngest patients experienced SP at a later stage of pregnancy than their older peers. Importantly, none of the women died. Among 41 women after SP, 24 (58.5%) had a spontaneous delivery, 11 (26.8%) underwent forceps delivery and 6 women (14.6%) had a caesarean section.4 Spontaneous delivery is safe following a primary SP, however, it is suggested that these women should be closely monitored during labour as the risk of recurrence is not negligible and reported to be difficult to identify during labour.4
Recurrence of SP has been associated with presence of pulmonary fibrosis, being of tall and slender build and younger age.2 Smoking is reported to increase the risk of recurrence and was the only aetiology among the pregnant women.2,4 Recurrence of SP in pregnant women has been reported to be about 44% which is considerably higher than the rate seen among patients who were not pregnant, reported to be 30%.4,5 In a patient with little pulmonary reserve, there may be catastrophic consequences should an unrecognised large SP occur.1,4 The aetiology of SP is thought to be rupture of subpleural blebs2 and is clearly seen in our patient’s chest CT scan (fig 1). After SP in a pregnant woman it has been speculated that subsequent natural labour with increasing intrathoracic pressures from the repeated Valsalva manoeuvres may cause recurrence of SP.4 We therefore felt it safer for mother and child to undergo caesarean section considering the considerable distress she experienced during her pneumothorax.
The British guideline for management of SP is very detailed as how to manage the acute event of SP, however there are no recommendations whether or not to evaluate the patient for the presence of an underlying condition.1 Our patient had been diagnosed as having childhood asthma, although a fixed obstructive lung disease was revealed in this young non-smoking woman. Pneumothorax may occur during an acute asthma attack, but it is a rare event reported as 1 case of pneumothorax and 1 of pneumomediastinum among 1016 adults admitted over a 4-year period.5
The most common cause of secondary SP is chronic obstructive pulmonary disease (COPD) and is correlated with FEV1 being less than 1 litre.2 Our patient had a severe obstructive ventilatory defect and lack of reversibility, even after a course of systemic oral steroids for 12 days. She is very young, has not smoked and her α1 antitrypsin was normal, ruling out known aetiologies of COPD. Her chest CT scan revealed bilateral diffuse bronchiectasis (fig 1) a condition often confused clinically with asthma.6 She underwent a comprehensive evaluation for known causes of this condition, which is also associated with an obstructive ventilatory defect. Our main concern was cystic fibrosis (CF) although she did not have typical issues such as cough and spit; she became pregnant naturally, there was no family history of CF, and it was ruled by a normal sweat test.6 Among patients with CF the occurrence of SP is far more common than in the general population (3.5% of all patients with CF) and is related to having reduced pulmonary function tests and it is associated with a subsequent higher mortality. Other known causes of bronchiectasis include rheumatic disease, immune deficiencies, inflammatory bowel disease, mycobacterial infections and repeated childhood infections, which we ruled out clinically, serologically and by sputum sample,6 thus concluding our patient had idiopathic or congenital bronchiectasis, which recently has been associated with chronic infection with non-typeable Haemophilus influenzae and an aberrant immune response.7
In summary, we report a young pregnant woman with a third trimester SP. We recommended caesarean section when she presented in labour 4 weeks later. Most reported pregnant women with SP have no underlying lung disease but are often found to be smokers and they may continue in natural childbirth. Our patient was found to have had secondary SP with a severe fixed obstructive ventilatory defect and diffuse bilateral bronchiectasis on CT scan. The latter is most likely either congenital or idiopathic, as we have ruled out known causes. It is unknown how best to manage labour after a secondary SP. We recommend close follow-up during any future pregnancy because of her limited ventilatory reserve. Surgical or chemical pleurodesis should be considered and is recommended by the guidelines, although her physiological and radiological findings would suggest that in the future she may be a candidate for lung transplantation, which may be very difficult after pleurodesis.
Young women who experience a spontaneous pneumothorax should be evaluated for an underlying lung condition in order for appropriate recommendations to be made during labour and any future pregnancy.
A pregnant woman having had a primary spontaneous pneumothorax may proceed in natural labour under close monitoring for recurrence (reported to be about 40%).
There are no clear recommendations how to manage a woman with secondary spontaneous pneumothorax due to underlying lung conditions, in which case a caesarean section should be considered.
Women younger than 20 years of age appear to be more likely to have a spontaneous pneumothorax at a later stage of pregnancy than their older peers.
Competing interests: None.
Patient consent: Patient/guardian consent was obtained for publication.