NIV is a form of ventilatory support that is increasingly used in patients in hypercarbic respiratory failure (1
). However, there is still no consensus on its use in hypoxic respiratory failure (4
). Nevertheless, a growing number of studies have demonstrated that NIV prevents the need for intubation and decreases mortality and hospitalisation time when it is used in hypoxic respiratory failure (1
). The primary goal of the use of NIV is to restore the gas exchange and reduce the respiratory workload without intubation.
Asthma is the most common disease leading to complications during pregnancy (6
). It affects 3-12% of pregnant women worldwide, and its prevalence in this subset is increasing (7
). Asthma may improve, worsen or remain unchanged during pregnancy. The worsening of asthma during pregnancy has been associated with the patient previously being asthmatic, discontinuation of inhaled corticosteroids, and viral infections, to which pregnant women are more prone due to changes in cell-mediated immunity. This may be one of the main underlying causes of asthma attacks (7
). Severe attacks requiring hospitalisation may be seen during all stages of pregnancy, but they often occur at 21-24 weeks. Attacks requiring hospitalisation occur in 1.6% of asthmatic pregnant women, while 12.6% of these women present to emergency departments (9
). Also, intubation is eight times more likely to be difficult in pregnant women than in non-pregnant women (10
). Soft tissue oedema makes the airway anatomy invisible, increasing the risk for hypoxaemic cardiac arrest and pulmonary aspiration. Therefore, NIV administered under close monitoring may be life-saving in cases of respiratory failure in pregnant women, as demonstrated here.
Treatment of asthmatic pregnant women requires special consideration to protect the foetus from hypoxic injury. Hormones such as progesterone and β-human chorionic gonadotropin cause changes in the respiratory system during pregnancy, such as the height of the diaphragm, which rises approx. 2 cm due to changes in the anteroposterior and transverse diameter of the rib cage in response to increased respiratory stimulation. This factor must be considered in NIV implementation, and lower pressures must be used in the initial stages to avoid dynamic hyperinflation and reduce the respiratory workload (6
The objective in pregnant women with respiratory failure is to provide efficient oxygenation and simultaneously implement mechanical ventilation to protect the lungs.
In spite of these data, there are few case reports of NIV implementation (10
). In these series, NIV successfully prevented the need for intubation and decreased hospitalisation time. In four cases with acute chest syndrome due to sickle-cell anaemia, Al-Ansari et al
. successfully applied NIV and stated that its implementation under close monitoring in hypoxic respiratory failure in pregnant women would shorten hospitalisation and ICU times (11
). Banga et al
. managed acute respiratory distress and hypoxic respiratory failure that had developed due to community-acquired pneumonia in a pregnant woman similar to our case with 3 days of NIV, after which the patient was transferred to the ward on the third day (12
). In our patient, NIV was implemented for 27 h, after which she was disconnected from the ventilator and taken to the ward. Several studies have reported that early NIV implementation is beneficial in pneumonia cases and ARDS, but there is still no consensus on this issue (1
This case contained some clinical features that should be emphasised. First, it demonstrated that viral infections may induce an asthma attack and facilitate pneumonia. Also, discontinuation of inhaled steroids can lead to hyper-reactivity of the airway towards respiratory tract irritants. As a result, the patient developed an asthma attack and lobar pneumonia with hypoxic respiratory failure. Since reduction of the respiratory workload was impossible with medical therapy at this stage, NIV was required, which avoided intubation and its resultant complications.
In conclusion, pneumonia may worsen hypoxia in a pregnant woman in asthma attack. Efficient monitoring and NIV with controlled increases in pressure can eliminate the need for intubation and can overcome acute hypoxic respiratory failure. Since NIV has been utilised in a very limited number of cases, this report is considered a successful clinical contribution.