Susana Moreira

Hypoxia challenge test and retinal circulation changes - a study using ocular coherence tomography angiography

Previous studies report that the response of retinal vessels to a decrease in oxygen (hypoxia) is vasodilation, thus increasing blood flow. We aimed to characterize the changes in retinal microvasculature induced by a mild hypoxia stress test in a healthy population, using ocular coherence tomography angiography (OCT‐A) technology.

An Unusual Association in an Uncommon Disease: Two Cases of Spontaneous Pneumomediastinum Associated with Pneumorrhachis

Pneumomediastinum, the presence of free air in the mediastinum, is described as spontaneous pneumomediastinum when there is no apparent cause such as trauma, surgery, interventional procedures, or intrathoracic infections. Pneumorrhachis is a rare clinical condition, consisting of intraspinal air. The main causes are iatrogenic, traumatic, and nontraumatic. Spontaneous mediastinum is usually associated with subcutaneous emphysema and, occasionally, with pneumothorax; however, its association with pneumorrhachis is extremely rare. Here, we present two rare cases of spontaneous pneumomediastinum associated with pneumorrhachis caused by vigorous coughing.

Morgagni Hernia as a Reversible Cause of Hypercapnic Respiratory Failure

The three basic types of congenital diaphragmatic hernia (CDH) include hiatus hernia, posterolateral Bochdalek hernia and anterior Morgagni hernia (MH), the last being the rarest type (2–3% of all cases).1,2 The diagnosis of MH in adults is very rare and usually is incidental or presents with non-specific chronic respiratory or gastrointestinal symptoms.2,3 It can also be present with acute bowel obstruction or intestinal strangulation.3 Late-presenting CDH is often difficult to diagnose, and delays in treatment are common.4 Few cases have been described in the literature. A 64-year-old non-smoker caucasian woman, with previous diagnosis of morbid obesity (BMI of 50 kg/m2), arterial hypertension, hypertensive heart disease, hypothyroidism and depression was first admitted to our department in 2007 with a one-month history of progressive exertional dyspnoea, paroxysmal nocturnal dyspnoea and lower limb oedema, with no other symptoms. There was no history of recent trauma or surgery. On admission, she was started on non-invasive ventilation (NIV) for hypercapnic respiratory failure (pH 7.35, PaCO2 72.4 and PaO2 40.2 mmHg). The initial chest radiographs showed an hypotransparency on the right pulmonary lower lobe. The chest CT scan identified a large Morgagni hernia on the right side, with the compromise of the right lung volume and contralateral mediastinal deviation, as well as signs of pulmonary hypertension. The echocardiogram confirmed mild pulmonary hypertension (PSAP 49 mmHg). She was referred to Cardiothoracic Surgery but was refused because of her surgery-related risk. She was discharged on long-term supplemental oxygen therapy and domiciliary NIV. Between 2008 and 2012 she was admitted three times for decompensated hypercapnic respiratory failure and for oxygen and ventilatory parameters adjustment. Diaphragmatic hernia was also bigger on the chest radiographs. In 2013 she was admitted five times in the context of emesis and gastroparesis. Despite a significant weight loss (BMI 50 to 41 kg/m2), she maintained the need for both long-term supplemental oxygen therapy and NIV. At that time her lung function test showed a moderately severe obstructive pattern (FVC 1.05 mL (67%); FEV1 0.64 mL (52%); FEV1/FVC ratio 61.14%; TLC 2.87 mL (82%); RV 1.76 mL (106%); ITGV 2.50 (112%)). A new CT scan showed increased volume of the Morgagni hernia, which contained part of the transverse colon, all the ascending colon, loops of ileum and distal jejunum, with the insinuation of gastric antrum, leading to passive atelectasis of the middle lobe

The importance of completing the hipoxic challenge test in assessing the risk of altitude in air travel: Experience of flight fitness evaluation

The atmospheric pressure in cabin of the pressurized commercial aircraft is not equivalent to the pressure at sea level. If this hypobaric environment doesn9t trigger symptoms in most of people, the same is not true for patients with respiratory disease. Since the increase of air travel and the need to advice the patients to this particular setting, British Thoracic Society (BTS) have published recommendations to evaluate and prescript supplemental oxygen in these conditions. The present study describes 2 years9 experience in advice respiratory patients on flight fitness in Hospital Santa Maria. During this period, 64 patients were evaluated (54% men, mean age 46±21 years) and underwent Hypoxic Challenge Test (HCT) with a protocol in agreement with BTS guidelines. Relatively to diagnosis, 46% had cystic fibrosis, 18% chronic obstructive pulmonary disease, 12% intersticial lung disease, 7% thoracic neoplasm, 7% bronchiectasis and 3% had obstructive sleep apnoea. Six of these patients had respiratory failure and were on long-term oxygen therapy (LTOT). At baseline, 60% of patients had SpO 2 > 95%, 31% between 92-95% and 9% 2 >95% maintained their PaO 2 >55 mmHg. Twelve patients with a sea level SpO 2 between 92-95% desaturated to PaO 2 Supplemental oxygen therapy was prescribed to 31 patients and in the 6 patients on LTOT the debit was measured and increased in all of them. In conclusion, despite the recommendations indicate only the HCT for patients with SpO 2