Acute respiratory failure (ARF) occurs in less than 0.1% of pregnancies; however, it is one of the most common reasons for obstetric admissions to the intensive care unit (ICU) and carries a high mortality for both mother and fetus. Pulmonary physiological and anatomic adaptations during pregnancy affect the overall management, as well as predispose patients to complications during respiratory illness. Pregnancyrelated upper airway mucosal oedema may obstruct visualisation of the airway during intubation and can make invasive airway management difficult. The pregnant female requiring endotracheal intubation has a four-fold higher risk of having a difficult airway and an eight-fold higher risk of a failed intubation [1].The application of noninvasive ventilation (NIV) in the treatment of ARF continues to expand as its benefits are increasingly recognised. NIV is often avoided in pregnancy due to the theoretical risk of aspiration. However, our current knowledge regarding the safety and efficacy of NIV for the management of respiratory failure in pregnancy is based on weak evidence. Only a few case reports and small case series have been published. Given the limited data, we review the current literature and report two cases of pregnant females who developed ARF from acute respiratory distress syndrome (ARDS) and were successfully and safely managed with NIV.
Case 1A 30-year-old gravida 2 para 1 with an uncomplicated twin pregnancy presented with premature rupture of membranes at 30 weeks of gestation. She had also complained of a dry cough for 1 week prior to presentation and a low grade fever. Corticosteroids, antibiotics and tocolytic therapy were administered. On day 2 of admission, she developed acute shortness of breath and complained of severe chest pressure and worsening cough. Her oxygen saturation was 87% while breathing room air. On physical examination, she appeared to be in moderate respiratory distress, was alert and awake, and had reduced breath sounds bilaterally. Rhonchi were auscultated over her right lung field and she was subsequently transferred to the medical ICU.Arterial blood gas (ABG) results on 100% oxygen via a non-rebreather mask showed an oxygen tension (PO 2 ) of 58 mmHg, pH of 7.49 and a carbon dioxide tension (PCO 2 ) of 27 mmHg. Her breathing became more laboured and the decision was made to place her on NIV with an inspiratory pressure of 12 cmH 2 O and an expiratory pressure of 5 cmH 2 O. Inspiratory oxygen fraction (FIO 2 ) was set to 100%. Fetal monitoring was initiated. Her work of breathing and oxygenation rapidly improved. Repeat ABG analysis 1 h later revealed a PO 2 of 152 mmHg on the same settings. Clindamycin was added for suspected aspiration pneumonia. Computed tomography of the chest showed diffuse, bilateral airspace disease. An echocardiogram was unremarkable. Over the next 2 days she was weaned off NIV and her clinical condition continued to improve. She tolerated the mask well and no episodes of aspiration or other complications occurred. However, her contractions...