Safety of Air Travel in H1N1-positive Patient with Hydropneumothorax.

Sir,

A 23-year-old tourist on a visit to India presented to the emergency department with fever, vomiting, and loose motions for past 7 days, followed by breathlessness and chest pain for the past 1 day. Clinical examination revealed tachypnea with room air saturation of 79%, bilateral crackles, and decreased air entry over the right base. Nonhomogeneous opacities were seen bilaterally in lower lobes of lung on chest X-ray. H1N1 infection was confirmed by using real-time reverse-transcriptase polymerase chain reaction. She was admitted in an intensive care unit where broad-spectrum antibiotics and oseltamivir (150 mg bid) were administered to her.

During her stay, she developed right-sided pleural effusion, which was drained twice at an interval of 2 days, 1 l and 500 ml in amount, respectively. It was exudative with neutrophilic predominance (90%) and sterile on bacterial and fungal cultures. The patient developed breathlessness and drop in PaO2 following second pleural tap. Chest X-ray, ultrasound, and contrast-enhanced computerized tomography of chest reported loculated hydropneumothorax with consolidation and multiple areas of necrosis and breakdown in the right lung. Clinical improvement was seen after insertion of intercostal chest drain (ICD). Oxygenation was maintained by using a face mask (FiO2=0.5), and she did not require any mechanical ventilation. ICD was removed after 5 days, and she was discharged after radiologic clearance of hydropneumothorax.

The patient boarded a 13-h long flight just 5 days after the removal of her chest drain. She remained asymptomatic in the flight but a repeat chest radiograph taken a day after demonstrated a small pneumothorax, which was managed conservatively.

Modern airlines are pressurized up to 549.5 mm Hg (three fourths of the normal atmospheric pressure), which corresponds to an altitude of 8000 ft. A person with a history of pneumothorax may have some air trapped in the thoracic cavity and this reduction in the external pressure can lead to expansion of this air, reoccurrence of pneumothorax, and lung collapse.[1] Breathing in pure oxygen from a face mask tightly sealed to the nasal and mouth region is the best approach to manage such a situation during air travel.

The Aerospace Medicine Association has suggested the avoidance of air travel for 2–3 weeks after radiographic resolution of pneumothorax,[2] but the British Thoracic Society guidelines recommend a delay of 6 weeks after an episode of primary spontaneous pneumothorax.[3] There is one previous study of 12 patients that establishes the safety of air travel 14 days after radiographic resolution of traumatic pneumothorax.[4] However, complications were reported in 2 patients who flew before 14 days.[4] The most feared complication is the development of tension pneumothorax.

Our patient had traveled against medical advice and developed clinically silent pneumothorax. In the case of pandemics such as H1N1 in which lung involvement is common, it is thus important to have a chest radiography to detect any underlying lung pathology for all tourists planning air travel and formulate stringent guidelines related to this. An alternative is to travel with a chest drain, and recommendations for air travel of passengers with chest tubes advocate the use of a Heimlich valve assembly in the chest drain to guarantee continuous aspiration during the flight.[5]