Respiratory rehabilitation for patients with COVID-19 infection and chronic respiratory failure: a real-life retrospective study by a Lombard network

The Lombardy region has been one of the areas most affected by the COVID-19 pandemic since the first months of 2020, providing real-life experiences in the acute phase. It is unclear how the respiratory rehabilitation network responded to this emergency. The aims of this retrospective study were: i) to analyze clinical, functional, and disability data at admission; ii) describe assessment tools and rehabilitative programs; iii) evaluate improvement after rehabilitation. The study was conducted on data collected from ten pulmonary rehabilitation centers in Lombardy, between the period of March 1st 2020 to March 1st 2021, in patients with respiratory failure recovering from COVID-19 both at admission and discharge. The study included demographics, comorbidities, nutritional status, risk of falls, disability status (Barthel index; Short Physical Performance Battery (SPPB); 6 minutes walking test (6MWT), symptoms (dyspnoea with Barthel Dyspnoea and MRC Dyspnoea Scale), length of stay, discharge destination, need for mechanical ventilation, respiratory function, assessment/outcomes indices, and prescribed rehabilitative programs. 413 patients were analyzed. Length of stay in acute and rehabilitative units was less than 30 days. Fifty % of patients used non-invasive ventilation during their stay. Functional status was mildly compromised for forced volumes and oxygenation, while severely compromised for diffusion capacity. Independency was low while physical performance status very low.  At discharge, 318 (77%) patients were sent home, 83 (20.1%) were transferred to an acute unit and 12 (2.9%) passed away. Barthel Index and 6MWT were the most used, while MRC score was the least used outcome parameter. The 5 main rehabilitative activities were walking (90.8 %), transfer from bed to armchair (77.5%), limb mobilization in bed (76%), balance (71.2%), and cycle-ergometer or treadmill (43.1%). A huge difference was found in admission, discharge, and delta change among different rehabilitative centers. When available, all outcomes showed a significant improvement. With the limitation of a retrospective study with a clear amount of missing data, COVID-19 subjects admitted to rehabilitative centers presented a reduced physical performance, symptoms of dyspnoea, and severe disability. The 6MWT and Barthel index were the most used measurement.

Controlled administration of dehydrochloromethyltestosterone in humans: Urinary excretion and long-term detection of metabolites for anti-doping purpose

Dehydrochloromethyltestosterone (DHCMT) is an anabolic-androgenic steroid that was developed by Jenapharm in the 1960s and was marketed as Oral Turinabol®. It is prohibited in sports at all times; nevertheless, there are several findings by anti-doping laboratories every year. New long-term metabolites have been proposed in 2011/12, which resulted in adverse analytical findings in retests of the Olympic games of 2008 and 2012. However, no controlled administration trial monitoring these long-term metabolites was reported until now. In this study, DHCMT (5 mg, p.o.) was administered to five healthy male volunteers and their urine samples were collected for a total of 60 days. The unconjugated and the glucuronidated fraction were analyzed separately by gas chromatography coupled to tandem mass spectrometry. The formation of the described long-term metabolites was verified, and their excretion monitored in detail. Due to interindividual differences there were several varieties in the excretion profiles among the volunteers. The metabolite M3, which has a fully reduced A-ring and modified D-ring structure, was identified by comparison with reference material as 4α-chloro-17β-hydroxymethyl-17α-methyl-18-nor-5α-androstan-13-en-3α-ol. It was found to be suitable as long-term marker for the intake of DHCMT in four of the volunteers. In one of the volunteers, it was detectable for 45 days after single oral dose administration. However, in two of the volunteers M5 (already published as long-term metabolite in the 1990s) showed longer detection windows. In one volunteer M3 was undetectable but another metabolite, M2, was found as the longest detectable metabolite. The last sample clearly identified as positive was collected between 9.9 and 44.9 days. Furthermore, the metabolite epiM4 (partially reduced A-ring and a modified D-ring structure which is epimerized in position 17 compared to M3) was identified in the urine of all volunteers with the help of chemically synthesized reference as 4-chloro-17α-hydroxymethyl-17β-methyl-18-nor-androsta-4,13-dien-3β-ol. It may serve as additional confirmatory metabolite. It is highly recommended to screen for all known metabolites in both fractions, glucuronidated and unconjugated, to improve identification of cheating athletes. This study also offers some deeper insights into the metabolism of DHCMT and of 17α-methyl steroids in general.

Syncope at SARS-CoV-2 onset

We describe clinical and laboratory findings in 35 patients tested positive for SARS-CoV-2 by reverse transcriptase-polymerase chain reaction on nasopharyngeal swab experiencing one or multiple syncope at disease onset. Clinical neurologic and cardiologic examination, and electrocardiographic findings were normal. Chest computed tomography showed findings consistent with interstitial pneumonia. Arterial blood gas analysis showed low pO2, pCO2, and ratio of arterial oxygen partial pressure to fractional inspired oxygen (PaO2/FiO2) indicating hypocapnic hypoxemia. Patients who presented with syncope showed significantly lower heart rate as compared to 68 SARS-CoV-2 positive that did not. Such poorer than expected compensatory heart rate increase may have led to syncope based on individual susceptibility. We speculate that SARS-CoV-2 could have caused angiotensin-converting enzyme-2 (ACE2) receptor internalization in the nucleus of the solitary tract and other midbrain nuclei, impairing baroreflex and chemoreceptor response, and inhibiting the compensatory tachycardia during acute hypocapnic hypoxemia.

Long-term non-invasive ventilation increases chemosensitivity and leptin in obesity-hypoventilation syndrome

BACKGROUND

Long-term nocturnal non-invasive mechanical ventilation (NIMV) is an effective treatment for obesity-hypoventilation syndrome (OHS), improving central carbon dioxide (CO(2)) sensitivity. Leptin might contribute to sustain adequate ventilation in obesity. The aim of the study was to investigate the role of leptin in the OHS pathogenesis looking at its relationship to CO(2) sensitivity before and after NIMV in OHS patients.

METHODS

In six obese patients (3F/3M; aged 63+/-9 yr; BMI 47.0+/-4.5 kg/m(2)) with OHS and without obstructive sleep apnoea-hypopnoea (OSAH) diurnal arterial blood gases, fasting plasma leptin concentration and CO(2) chemosensitivity were determined before and after 10.3+/-5.6 (range 6-20) months of NIMV.

RESULTS

After NIMV improvements were observed in gas exchange (PaO(2) from 51.3+/-6.7 to 75.0+/-10.3 mmHg, p<0.01; PaCO(2) from 55.5+/-4.8 to 43.7+/-1.2 mmHg, p<0.01; [HCO(3)(-)] from 33.3+/-3.8 to 29.8+/-1.7 mmol/l, p<0.05) and CO(2) chemosensitivity, measured as P(0.1)/PetCO(2) slope (from 0.09+/-0.07 to 0.18+/-0.07 cmH(2)O/mmHg, p<0.05) and V(E)/PetCO(2) slope (from 0.4+/-0.3 to 0.9+/-0.5l/min/mmHg, p=0.07). Plasma leptin increased from 34.5+/-21.1 ng/ml to 50.2+/-22.9 ng/ml (p<0.01) after NIMV and changes of the P(0.1)/PetCO(2) slope correlated with percent changes of plasma leptin (r(2)=0.79, p<0.05).

CONCLUSIONS

These findings suggest a possible role of leptin in the recovery of neuromuscular response to hypercapnia obtained during long-term nocturnal NIMV in OHS patients without OSAH.