Corticosteroid treatment has no effect on hospital mortality in COVID-19 patients.

Since the start of the novel coronavirus 2019 (COVID-19) pandemic, corticosteroid use has been the subject of debate. The available evidence is uncertain, and knowledge on the subject is evolving. The aim of our cohort study was to evaluate the association between corticosteroid therapy and hospital mortality, in patients hospitalized with COVID-19 after balancing for possible confounders. One thousand four hundred forty four patients were admitted to our hospital with a positive RT-PCR test for SARS-CoV-2, 559 patients (39%) were exposed to corticosteroids during hospital stay, 844 (61%) were not exposed to corticosteroids. In the cohort of patients exposed to corticosteroids, 171 (30.6%) died. In the cohort of patients not exposed to corticosteroids, 183 (21.7%) died (unadjusted p < 0.001). Nonetheless, exposure to corticosteroids was not associated with in-hospital mortality after balancing with overlap weight propensity score (adjusted p = 0.25). Patients in the corticosteroids cohort had a reduced risk of ICU admission (adjusted p < 0.001). Treatment with corticosteroids did not affect hospital mortality in patients with COVID-19 after balancing for confounders. A possible advantage of corticosteroid therapy was to reduce Intensive Care Unit admission, which could be useful in reducing pressure on Intensive Care Units in times of limited resources, as during the COVID-19 pandemic.

Normal values of exhaled carbon monoxide in healthy subjects: comparison between two methods of assessment.

BACKGROUND: In a previous study, exhaled carbon monoxide (eCO) has been assessed in healthy non-smokers with a photo acoustic spectrometer Brüel&Kjær 1312. Unexpectedly, values were higher than those reported in literature, which were mostly obtained with electrochemical analysers. This study was aimed to compare eCO values obtained with Brüel&Kjær 1312 and PiCO + Smokerlyzer, a largely utilized electrochemical analyser. METHODS: Thirty-four healthy subjects, 15 non-smokers and 19 smokers, underwent eCO assessment with Brüel&Kjær 1312 and PiCO + Smokerlyzer during a prolonged expiration (15 seconds). Brüel&Kjær 1312 assessed CO concentration 7 and 12 seconds after the beginning of expiration and displayed the mean value. PiCO + Smokerlyzer was utilized according to the manufacturer's recommendations. In vitro, the two devices were tested with standard concentrations of CO in nitrogen (5, 9.9, 20, and 50 ppm), and the time needed by PiCO + Smokerlyzer readings to stabilize was assessed at different gas flows. RESULTS: Both Brüel&Kjær 1312 and PiCO + Smokerlyzer presented very good internal consistency. The values provided were strictly correlated, but at low test concentrations, the Brüel&Kjær 1312 readings were greater than the PiCO + Smokerlyzer, and vice versa. PiCO + Smokerlyzer overestimated the CO standard concentrations at 5 and 9.9 ppm by 20%, while Brüel&Kjær 1312 measures were correct. PiCO + Smokerlyzer readings stabilized in 12 seconds during in vitro tests and in 15 seconds during in vivo measurements, suggesting that the values displayed corresponded to the initial phase of expiration. CONCLUSIONS: Differences between Brüel&Kjær 1312 and PiCO + Smokerlyzer may be explained because Brüel&Kjær 1312 measured CO levels in the middle and at the end of expiration while PiCO + Smokerlyzer assessed them in the initial part of expiration.

Ultrasound artifacts mimicking pleural sliding after pneumonectomy.

STUDY OBJECTIVE: To determine the presence of pleural sliding on chest ultrasonography (US) in a series of patients admitted to a surgical intensive care unit (SICU). DESIGN: Prospective, observational study. SETTING: 16-bed SICU of a University hospital. PATIENTS: 8 patients (7 men, 1 woman), aged 64 - 73 years (mean 67.5 yrs). Seven patients underwent pneumonectomy for pulmonary neoplasms; one patient underwent an atypical lung resection after having undergone a pneumonectomy one year before. INTERVENTIONS: None. MEASUREMENTS: Chest ultrasounds were performed during mechanical ventilation and spontaneous ventilation after endotracheal tube removal. In both examinations, pleural sliding was searched bilaterally in brightness mode (B-mode) and motion mode (M-mode) on the anterior thoracic wall in the least gravitationally dependent areas. RESULTS: During mechanical ventilation, pleural sliding was always absent on the side of the pneumonectomy and present on the other side. During spontaneous ventilation, some artifacts mimicking pleural sliding were noted on the side of the pneumonectomy both in B-mode and M-mode (presence of the seashore sign) in all patients, except for the one patient who had undergone a pneumonectomy one year earlier. Those artifacts became more pronounced during deep breaths. CONCLUSIONS: Ultrasound artifacts mimicking pleural sliding may be observed in the absence of the lung and may originate from the activity of intercostal muscles since they become more evident during deep breathing.

Compression of the inferior vena cava in bowel obstruction.

INTRODUCTION: We investigated whether (a) the inferior vena cava (IVC) is compressed in bowel obstruction and (b) some tracts are more compressed than others. METHODS: Two groups of abdominal computed tomography (CT) examinations were collected retrospectively. Group O (N = 69) scans were positive for bowel obstruction, group C (N = 50) scans were negative for diseases. IVC anteroposterior and lateral diameters (APD, LAD) were assessed at seven levels. RESULTS: In group C, IVC section had an elliptic shape (APD/LAD: .76 ± .14), the area of which increased gradually from 1.9 (confluence of the iliac veins) to 3.1 cm²/m² of BSA (confluence of the hepatic veins) with a significant narrowing in the hepatic section. In group O, bowel obstruction caused a compression of IVC (APD/LAD: .54 ± .17). Along its course, IVC section area increased from 1.3 to 2.5 cm²/m². At ROC curve analysis, an APD/LAD ratio lower than 0.63 above the confluence of the iliac veins discriminated between O and C groups with sensitivity of 74% and specificity of 96%. CONCLUSIONS: Bowel obstruction caused a compression of IVC, which involved its entire course except for the terminal section. APD/LAD ratio may be useful to monitor the degree of compression.

Sonographic assessment of abdominal vein dimensional and hemodynamic changes induced in human volunteers by a model of abdominal hypertension.

OBJECTIVE: In patients affected by intra-abdominal hypertension, bladder or gastric pressure measurement may be usefully integrated by ultrasounds in order to detect early hemodynamic impairment. The purpose of this study was to search for changes in abdominal vein size and flow induced by intra-abdominal hypertension. DESIGN: Physiologic study. SETTING: Postoperative intensive care unit of a university hospital. SUBJECTS: Sixteen healthy volunteers. INTERVENTIONS: Four echographic assessments of vessel sizes and blood velocities were randomly performed in the following settings: 1) baseline, 2) intra-abdominal hypertension simulated by a tight pelvic stabilizer around the waist, 3) noninvasive ventilation with a facial mask, and 4) intra-abdominal hypertension plus noninvasive ventilation. MEASUREMENTS AND MAIN RESULTS: The model of intra-abdominal hypertension was validated in eight subjects by measuring gastric pressure. During intra-abdominal hypertension, 1) the inferior vena cava was compressed (significant decrease of both anteroposterior and lateral diameters) and deformed (decreased anteroposterior/lateral diameter ratio), and deformation, but not compression, was attenuated by noninvasive ventilation associated with intra-abdominal hypertension; 2) the portal vein was also compressed (decreased diameter); and 3) blood velocities did not change significantly in the inferior vena cava, portal vein, right suprahepatic vein, or right external iliac vein. In the receiver operating characteristic curve analysis, an inferior vena cava section area (normalized for body surface) of lower than 1 cm²/m² discriminated between intra-abdominal hypertension presence and absence with a sensitivity of 65.6% and a specificity of 87.5% (p = .0001). Noninvasive ventilation alone did not significantly affect vein sizes and velocities. The resistive index, calculated by pulse wave Doppler signal from segmental branches of the right renal artery, increased slightly, but significantly, during intra-abdominal hypertension alone, suggesting an increase of intrarenal pressure. CONCLUSIONS: Simulated intra-abdominal hypertension was associated with decreased inferior vena cava section area and increased resistive index in renal arteries. Further studies are now needed to investigate whether these changes may be of value to integrate bladder or gastric pressure measurement in clinical practice.

Effects of acute hypoventilation and hyperventilation on exhaled carbon monoxide measurement in healthy volunteers.

BACKGROUND: High levels of exhaled carbon monoxide (eCO) are a marker of airway or lung inflammation. We investigated whether hypo- or hyperventilation can affect measured values. METHODS: Ten healthy volunteers were trained to achieve sustained end-tidal CO2 (etCO(2)) concentrations of 30 (hyperventilation), 40 (normoventilation), and 50 mmHg (hypoventilation). As soon as target etCO(2) values were achieved for 120 sec, exhaled breath was analyzed for eCO with a photoacoustic spectrometer. At etCO(2) values of 30 and 40 mmHg exhaled breath was sampled both after a deep inspiration and after a normal one. All measurements were performed in two different environmental conditions: A) ambient CO concentration = 0.8 ppm and B) ambient CO concentration = 1.7 ppm. RESULTS: During normoventilation, eCO mean (standard deviation) was 11.5 (0.8) ppm; it decreased to 10.3 (0.8) ppm during hyperventilation (p < 0.01) and increased to 11.9 (0.8) ppm during hypoventilation (p < 0.01). eCO changes were less pronounced than the correspondent etCO(2) changes (hyperventilation: 10% Vs 25% decrease; hypoventilation 3% Vs 25% increase). Taking a deep inspiration before breath sampling was associated with lower eCO values (p < 0.01), while environmental CO levels did not affect eCO measurement. CONCLUSIONS: eCO measurements should not be performed during marked acute hyperventilation, like that induced in this study, but the influence of less pronounced hyperventilation or of hypoventilation is probably negligible in clinical practice.