Clinical Approach to Patients with COVID-19 and Unrecognized Obstructive Sleep Apnea.

Purpose: We conducted a retrospective case series of seven male COVID-19 patients with respiratory failure and suspected OSA based on clinical features to evaluate the effects of undiagnosed obstructive sleep apnea (OSA) on COVID-19 outcomes and the response to a continuous positive airway pressure (CPAP) treatment. Cardiorespiratory polygraphy (CRP) and a continuous positive airway pressure treatment were used for diagnosis and management. They confirmed severe obstructive sleep apnea in all patients (apnea/hypopnea index > 30) and improved overnight oxygenation and symptoms at the 1-month follow-up. Conclusions: Undiagnosed obstructive sleep apnea may negatively impact COVID-19 outcomes by exacerbating respiratory failure. Recognition and treatment with continuous positive airway pressure can optimize the management of such patients.

Vaccination provides superior in vivo recall capacity of SARS-CoV-2-specific memory CD8 T cells.

Memory CD8 T cells play an important role in the protection against breakthrough infections with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Whether the route of antigen exposure impacts these cells at a functional level is incompletely characterized. Here, we compare the memory CD8 T cell response against a common SARS-CoV-2 epitope after vaccination, infection, or both. CD8 T cells demonstrate comparable functional capacity when restimulated directly ex vivo, independent of the antigenic history. However, analysis of T cell receptor usage shows that vaccination results in a narrower scope than infection alone or in combination with vaccination. Importantly, in an in vivo recall model, memory CD8 T cells from infected individuals show equal proliferation but secrete less tumor necrosis factor (TNF) compared with those from vaccinated people. This difference is negated when infected individuals have also been vaccinated. Our findings shed more light on the differences in susceptibility to re-infection after different routes of SARS-CoV-2 antigen exposure.

Arterial blood gases' analysis in elite breath-hold divers at extreme depths.

PURPOSE: To showcase results of arterial blood gases' analysis in elite breath-hold divers sampled at depths where their total lung capacities are below their residual lung volume on surface. METHODS: Three male elite breath-hold divers performed body plethysmographies to determine their lung volumes. Two dives were performed, one on normal inhalation to 60 m of depth and the second on complete exhalation to 10 m of depth. Blood samples were taken on five occasions; before the first dive, at 60 and 10 m of depth and immediately after resurfacing after both dives. RESULTS: Arterial blood gases' analysis at 60 m of depth showed an increase in partial pressures of oxygen and carbon dioxide, a consequent decrease in pH and an increase in concentration of HCO3-. After resurfacing, in two divers, values mostly returned to normal; hypoxemia was observed in one diver. At 10 m of depth, all values showed similar variation, and hypoxemia was observed in the same diver but at depth. Upon resurfacing, all values returned to normal. CONCLUSION: This is the first study performed at depths where the total lung capacities of participants are below their residual lung volumes at the surface. Partial pressure of carbon dioxide increases at depth to higher than normal values causing pH to decrease thus exceeding the buffering potential of the blood. In addition, previous assumptions that maximum depth in breath-hold divers is where total lung capacity is reduced to their residual volume proved wrong as our group of divers had no symptoms after resurfacing.

Extreme anaerobic exercise causes reduced cytotoxicity and increased cytokine production by peripheral blood lymphocytes.

Exercise has many beneficial effects for our body, but can become detrimental at high intensity, especially for our immune system. Little is known about the underlying mechanism of impaired immune functionality under conditions of intense physical strain. Freedivers, people who dive to high depths on a single breath, perform extreme exercise under anaerobic conditions. In this study, we investigated the impact of freediving on the cytotoxic arm of the immune system. At rest, elite freedivers did not display changes in their immunological profile compared to non-diving controls. In contrast, after a freedive, granzyme B and IL-2 production were reduced, whereas IFNγ and TNF secretion were increased by cytotoxic immune cells. Using in vitro models mimicking freedive conditions, we could show that hypoxia in combination with stress hyperglycemia had a negative impact on Granzyme B secretion, whereas IL-2 production was inhibited by stress hormones. Our findings suggest that in response to extreme exercise, cytotoxic immune cells transiently change their functional profile to limit tissue damage.

Haemoptysis in breath-hold divers; where does it come from?

INTRODUCTION: The aim of reporting these two cases is to present visual evidence by bronchoscopy of the origin of haemoptysis in two elite breath-hold divers. CASE REPORTS: Two male elite breath-hold divers of similar physical characteristics presented to our clinic after performing dives of up to 75 and 59 meters of seawater depth for 2:30 and 2:35 (minutes:seconds) respectively. Both patients presented with haemoptysis. Lung ultrasound was performed. The first patient had crackles on chest auscultation, overt pulmonary oedema clinically and 90 ultrasound lung comets. The second patient had no oedema or crackles, but presented with 20 ultrasound lung comets. Video bronchoscopy was performed which showed traces of blood coming from all three segments of the right upper lobe in both patients. The rest of the airways and lungs were intact. CONCLUSIONS: These finding suggest that the apical parts of the lungs are the most prone to deep-dive induced damage. The precise mechanism of lung barotrauma and haemoptysis in breath-hold divers remains to be elucidated. These findings may be of importance for a better understanding of the underlying pathology of haemoptysis.

Hyperbaric oxygen treatment: A complementary treatment modality of Modic changes?

Modic changes (MCs) have attracted great interest in recent years. The complex process of MC development and progression seems to involve interplay between mechanical, infective, inflammatory, and degenerative processes that cannot be clearly differentiated. Based on signal intensity on T1- and T2-weighted MRI scans, MCs can be divided three types: Type 1, Type 2, and Type 3. Predominantly Type 1 MCs are commonly associated with chronic low back pain that is unresponsive to classic treatment options. Infection with low-virulent anaerobic microorganisms, most commonly Propionibacterium acnes, has been implicated in MC development following a disc herniation when a tear enables bacteria to enter the disc. Recent studies in patients with chronic low back pain following a lumbar disc herniation associated with Type 1 MCs have reported promising results following prolonged systemic antibiotic treatment with amoxicillin-clavulanate. Hyperbaric oxygen therapy, as primary or adjuvant treatment in association combination with systemic antibiotics or anti-inflammatory therapy, could offer important advantages in treating patients with suspected low-virulent disc infections due to anaerobic microorganisms associated with Type 1 MCs. We believe that hyperbaric oxygenation could contribute to faster resolution of Type 1 MCs and associated pain through multiple effects-including direct antimicrobial effects through formation of reactive oxygen species (ROS), altering the favorable low oxygen tension milieu such that it becomes unfavorable for bacterial growth and survival, and anti-biofilm effects. Additionally, hyperbaric oxygenation could contribute to faster pain resolution via direct and indirect anti-inflammatory effects. As an adjuvant treatment administered in combination with systemic antibiotics, HBOT could increase the sensitivity of Propionibacterium acnes to antimicrobial drugs under hyperoxic conditions, resulting in faster MC resolution. Overall, the faster infection resolution, diminished bacterial load, and anti-inflammatory effects due to reduced cytokine expression and levels of infectious by-products could lead to faster pain resolution following HBOT, and a significant improvement of quality of life in these patients.

Accuracy of targeted wire guided tube thoracostomy in comparison to classical surgical chest tube placement - A clinical study.

BACKGROUND: Chest tube malfunction, after the tube thoracostomy, is often the result of an inappropriate chest tube tip position. The aim of this study was to analyse the precision of chest tube placement using the targeted wire guide technique (TWG technique) with curve dilator and to compare it to the classical surgical technique (CS technique). MATERIALS AND METHODS: In this clinical study 80 patients with an indication for thoracic drainage, due to pneumothorax or pleural effusion were included. Experimental group contained 39 patients whose chest tube was placed using the TWG technique. The control group contained 41 patients whose chest tube was placed using the CS technique. RESULTS: The comparison of the outcomes of the two techniques applied suggests that the TWG technique was significantly more successful in achieving adequate (precise) chest tube placement, irrespective of patient diagnosis (TWG vs. CS in all patients, 78.4% vs. 36.6%, p<0.001). In the pleural effusion group, TWG and CS had success rates of 78.2% and 37.5% (p=0.005), respectively, while in pneumothorax group, TWG and CS had success rates of 78.6% and 35.3% (p=0.029), respectively. CONCLUSIONS: Using a curved dilator and the TWG technique for the thoracic drainage procedure we found statistically significant advantage to the TWG technique in comparison to the CS technique (78% vs. 37%) regarding precise chest tube placement within the pleural cavity. Introducing the materials and technique used in this clinical trial into clinical practice may improve the quality of thoracic drainage, including residual volume of air and/or fluid, poor functioning of the chest tube, and, as a consequence of both, prolonged hospitalisation.

Primary spontaneous pneumothorax and mitral valve prolapse are not associated.

BACKGROUND: Mitral valve prolapse (MVP) is a common diagnosis in patients with primary spontaneous pneumothorax (PSP). This description assumes that MVP and PSP might be manifestations of a systemic connective tissue abnormality. The purpose of this study was to determine the prevalence of MVP in PSP patients of Croatian origin and evaluate their relationship with connective tissue disorders. We also examined the prevalence of PSP in patients with primary MVP. METHODS: Thirty-two patients with PSP and without underlying pulmonary disease or connective tissue disease underwent two-dimensional transthoracic echocardiography performed by a certified cardiologist. Echocardiography and demographic features were analyzed using descriptive statistics. We also examined the medical records of 60 patients with primary MVP. RESULTS: MVP was found in none of the 32 patients suffering from PSP. The age, sex, smoking status, body mass index, side, rate, and family history were similar to previous investigations. Likewise, none of the 60 patients with primary MVP ever had PSP. CONCLUSION: By applying an updated definition of MVP, we found no MVP case among PSP patients of Croatian origin. We also found no PSP in the primary MVP group. Ethnicity may influence the occurrence of MVP in PSP patients, and PSP in primary MVP patients.

Pneumocephalus after an uneventful scuba dive.

Scuba diving has become increasingly popular in the last 20 yr. Although it is considered safe, accidents, sometimes with fatal outcomes, do occur. The incidence of diving-related CNS barotrauma is low and it has been reported very infrequently. The clinical presentation may range from minimal dysesthesias to complete quadriplegia, encephalopathy, or death. In this paper we present a case of pneumocephalus in a 36-yr-old male scuba diver that presented with minor neurologic symptoms. A discussion, including a review of the literature, is also presented. The authors recommend that diving-induced neurologic dysbarism syndromes, including pneumocephalus, should be considered a possible cause when a scuba diver presents with neurologic symptoms, even minor ones.

Targeted wire-guided chest tube placement: a cadaver study.

OBJECTIVE: Chest tube thoracostomy is a standard procedure for pleural fluid and air drainage. The aim of this study is to compare the success rate of the targeted tube thoracostomy using two different techniques: a targeted wire-guided (TWG) technique and a classical surgical (CS) technique. METHODS: The study was performed on 153 human cadavers without documented pleural pathology, mechanically ventilated during the procedure. They were divided into two groups and to each cadaver a software generated random number was assigned. The TWG technique was applied on 76 and the CS technique on 77 cadavers. The TWG and CS groups were divided into four subgroups according to the four intended positions of the chest tube tip (target position in the pleural cavity): back-down-right, front-up-right, front-up-left and back-down-left. The precise position of the chest tube tip after thoracostomy was determined by autopsy. The placement of the thoracostomy tube was marked successful if the chest tube tip was located at an intended position. RESULTS: The success rate with the TWG technique was 79%, whereas with the CS technique it was 30%. CONCLUSION: A higher success rate was achieved with the TWG than with the CS thoracostomy technique.

[Malignant pleural mesothelioma in patients hospitalised at the Clinical Hospital Centre Rijeka between 1989 and 2008]. / Maligni mezoteliom pleure u bolesnika lijecenih u klinickome bolnickom centru Rijeka tijekom 1989-2008. Godine.

Malignant pleural mesothelioma (MPM) is a relatively rare tumour, mainly associated with occupational exposure to asbestos. We retrospectively analysed the records of MPM patients treated at the Pulmonology Department of the Clinic for Internal Diseases, Clinical Hospital Centre Rijeka between 1989 and 2008. to establish the incidence of MPM in that period. Between 1989 and 2008 the hospital received 121 MPM patients, 117 of whom were men and four women. We observed a continued increase in newly diagnosed MPM patients from year to year. Occupational exposure to asbestos was established in 72 patients who worked in shipbuilding. In our region the incidence of MPM has been rising significantly. We believe that this is not related to improved diagnostics, but to the long latency of the disease. This is why we expect this trend to continue for a while. In the U.S.A. and Europe, MPM incidence is expected to peak by 2020, while in countries with poor control over asbestos use this may take longer.