Description

A 48-year-old woman was transferred to our hospital because of non-resolving pneumonia with rapidly progressive respiratory failure.

She had no remarkable medical history or history of illicit drug use. She was admitted to her local hospital 5 days before coming to our hospital with 4 days of fever and dry cough. With a tentative diagnosis of atypical pneumonia, she was treated with intravenous minomycin (200 mg/day).

On admission (day 1), she was fully conscious and her vital signs were: temperature 37.2°C; heart rate 85 bpm; blood pressure 104/70 mm Hg; SpO₂ 90% on oxygen at 10 L/min by mask (arterial blood gas (ABG): pH 7.453, pCO₂ 39.1 Torr, pO₂ 54.4 Torr, HCO₃⁻ 27 mmol/L) and respiratory rate 36 bpm.

On physical examination, no adventitious breath sounds were noted, but the chest wall moved in during inhalation and out during exhalation together with dyssynchrony between the rib cage and abdomen (video 1), in a ‘seesaw’ type of motion, suggesting acute respiratory failure.

Chest X-ray (figure 1A) and thoracic CT (figure 1B) showed massive consolidation with air bronchogram and ground glass opacities in bilateral middle to lower lung lobes. Based on the radiological findings, the patient was diagnosed with acute interstitial pneumonia and was immediately treated with nasal high-flow oxygen therapy, intravenous steroid pulse therapy (1000 mg/day for 3 days/course for 3 courses) and an oral immunosuppressive drug (cyclosporine 150 mg/day). Three weeks later, her seesaw motion disappeared with respiratory status improvement (SpO2 98% on 3 L/min oxygen via nasal cannula, ABG: pH 7.431, pCO₂ 40.9 Torr, pO₂ 59.7 Torr, HCO₃^– 26.7 mmol/L). At that time, the lung lesions markedly improved as well (figure 1C, D).

• Download figure
• Open in new tab
• Download powerpoint

Figure 1

The pattern of respiration showing deflation of the lung during inspiration and inflation of the lung during expiration. Chest X-ray (A) and thoracic CT (B) on admission showed massive consolidation with air bronchogram and ground glass opacities in bilateral middle to lower lung fields. Three weeks later, those lesions almost disappeared except for faint ground glass opacities with mild consolidation and/or bronchiectasis (C and D).

Paradoxical respiration (seesaw motion) is a hallmark of inhibition of gas exchange due to diaphragmatic or respiratory muscle fatigue (ie, chronic obstructive lung disease)1 or traumatic injury to the thorax (flail chest), which may require urgent mechanical ventilation.